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This is a continuation-in-part of application Ser. No. 641,557 filed Aug. 16, 1984 and now U.S. Pat. No. 4,533,606.
INTRODUCTION
The present invention relates to an aqueous composition and process for electrodepositing a layer of zinc containing silicon and phosphorus on a metal substrate to improve wear resistance; protect against galling; and to improve resistance of the metal against corrosion and stress corrosion cracking. While essentially all metals of industrial importance may be plated, this process is especially important for ferrous metals, steels, stainless steels, copper, aluminum and titanium.
BACKGROUND OF THE INVENTION
Many attempts have been made in the past to improve the surface properties of metals in order to widen their applications. An early attempt was to improve corrosion resistance by coating one metal with one or more suitable metals. For instance, base metals have been coated with silver and/or gold, and iron has been coated with tin.
It is also known to use zinc or cadmium to protect iron or steel galvanically against corrosion.
A known process for providing an adherent, protective coating of zinc or zinc compounds on iron or steel is by hot dip galvanizing. This involves immersing the iron or steel object in a bath of molten zinc. However, the degree of protection provided by this process is highly dependent on the bath temperature, immersion time, rate of cooling or subsequent reheating. Moreover, the strength and impact toughness of the substrate is generally reduced, and the zinc coating tends to craze or crack if the hot dip galvanized substrate is subsequently formed by sharp bending.
Processes to electroplate a layer of zinc on steel have also been suggested. However, it is recognized that the protective effect of a zinc coating on steel is mainly sacrificial protection and only partially provided by the formation of an insoluble surface coating. The degree of protection against corrosion depends on the formation of an insoluble basic carbonate film. Any condition which interferes with the formation of this film will lead to rapid attack of the zinc coating and negate the protective effects provided. Further, zinc plating has proven to be unsatisfactory for protection against the corrosive effects of severe industrial environments.
Besides providing corrosion resistance, metals have been coated with cadmium to provide lubricity, solderability, and compatible electrical conductivity. Products coated with cadmium have found application particularly in the aerospace and automobile industries. Cadmium coated steels are used in aircrafts, aerospace fasteners, disc-brake components, radiator hose fittings, door latches and torsion-bar bolts. However, because of the toxicity of cadmium and the potential health hazards resulting therefrom, there are stringent federal and local regulations controlling the use of cadmium. This limits its application and increases its cost.
With the growth in use of metals in many industries, methods of joining metals together have been found to be essential. This led to the use of fasteners such as bolts, screw, springs, pins, etc. Many of these rely upon the use of threaded parts which are subjected to high torque loads to keep the metal components from pulling apart or becoming unfixed.
However, it has been found that when the threaded parts are highly torqued, they become susceptible to corrosion, such as by hydrogen sulfide attack, hydrogen embrittlement, chloride corrosion, stress corrosion cracking and oxidative attack.
To protect against such corrosive attacks, methods of plating or coating the threaded parts have been developed.
It is important that the coating or plating on the threaded parts be very thin so that it does not interfere with the thread make up. It is also important that the coating or plating adhere to the base metal, to provide a low coefficient of friction and protect against corrosive attack.
Methods of coating or plating threaded parts most commonly used today are galvanizing, zinc plating, phosphating, cadmium plating or coating with fluorocarbon polymers. However, these methods suffer from many disadvantages.
As an example, an ASTM B-7 bolt should have a maximum tensile strength of 80,000 lbs. and a usable temperature range of subzero to 600° C.
Galvanizing can only provide a coating with a tensile strength of about 40,000 lbs. The deposited layer is thick and special nuts are required for thread make up. Further, the smallest breakdown in the coating provides sites for accelerated corrosion whereby the nuts and bolts fuse together resulting in extra expenses for removal during maintenance.
Zinc electroplating also provide poor tensile strength and low resistance to corrosion.
Cadmium electroplating can provide a tensile strength of 70,000 lbs. and a low coefficient of friction. However, it only provides moderate protection against corrosion and any breakdown in the coating accelerates corrosive attack. And as stated previously, cadmium is highly toxic with severe environmental implications.
Phosphating can provide good mechanical properties, and act as a substrate for paints and fluorocarbon polymer coatings. However, by itself, phosphating does not provide sufficient protection against corrosion.
Fluorocarbon polymer coatings do provide good corrosion resistance and a low coefficient of friction. However, the usable temperature range is very limited and fluorocarbon polymers tend to flow excessively under stress.
Therefore, there is a critical need for a coating that is resistant to corrosion and will prevent galling, particularly in the oil exploration field.
Galling is a problem encountered frequently in oil and gas exploration. Galling describes a phenomenon when threads of connectors become forged or welded together as a result of having been subjected to high torque loading.
In the oil and gas exploration field increasing depths of drilling have been found to be necessary to obtain much needed energy resources. High temperatures and pressures coupled with aggressively corrosive environments such as hydrogen sulfide, hot boiling chlorides, carbon dioxide gas have compounded the problems of oil exploration and expensive metal alloys have been developed to meet the challenge.
Since it is not uncommon to drill wells of 15,000 feet or deeper, drilling pipes must be threaded together. Further, tool joints, pulsation dampers, blow out preventers, valves, electric measuring devices are used and all of these have threaded connections. The galling of threaded connections have been a severe problem in oil and gas exploration causing increased expenses in time and money.
Attempts have been made to overcome this problem with specially designed pipe threads and coatings such as electroless nickel, hard chromium. However, none of the coatings provide a satisfactory solution since most of the coatings break down under the high stress load required, and some of the coatings such as electroless nickel or hard chromium have uneven throwing power which leads to distortion of threaded parts which are specially designed to have close tolerance.
It has been found that the zinc/silicon/phosphorous deposit according to the present invention is surprisingly effective against corrosion of threaded joints and is particularly suitable for applications in the oil exploration field.
Another serious problem recently encountered is stress corrosion cracking of high strength alloys. These high strength alloys have been used in many different areas from satellites and space vehicles to cars, bridges and nuclear reactors. It is recognized that stress corrosion cracking is related to hydrogen embrittlement or attack by sulfides and chlorides in the environment. Sulfide induced stress corrosion cracking is generally considered to be a result of hydrogen embrittlement. When hydrogen atoms evolve cathodically on the surface of a metal, as a result of corrosion, the presence of hydrogen sulfide causes the hydrogen atoms to stay within the surface of the metal. These hydrogen atoms diffuse to regions of high triaxial tensile stress or regions where the microstructural configuration causes the hydrogen atoms to be trapped. The presence of hydrogen atoms increases the brittleness of the metal. Stress failure has been the major cause of airplane and auto crashes, and flaws in bridges and nuclear reactors. Up to the present, no viable solution to stress corrosion cracking of high strength alloys has been provided.
It has been found further that the zinc/silicon/phosphorus coating according to the present invention can improve the stress corrosion cracking resistance of these high strength alloys.
Wear and friction are also serious problems in metal engine components, where parts are in contact with each other, especially piston rings, cylinders, and auto transmission shafts. The rate of wear is directly related to the amount of friction between two moving components. Lubricants are used to reduce friction. However, in certain cases, lubricant oils may interfere with the function of the parts; furthermore dirty lubricant oils must be changed frequently, thus increasing the cost of operation and present disposal problems. Since the zinc/silicon/phosphorus coating provides a low coefficient of friction, it is particularly useful on metal parts which are in contact with each other.
The recognition of the need to improve resistance to corrosion, galling, wear, and stress corrosion cracking has led to the development of many methods of improving the surface characteristics of metals. One such known method is to "siliconize" metal substrates by exposing the metal substrate to high temperatures, in the range of 800°-1400° C., in an atmosphere of silicon tetrachloride and hydrogen. Alternatively, metal substrates may be siliconized by heating the metal sutstrates in the presence of silicides at a temperature sufficient to cause thermal decomposition of the silicide. Such siliconized metal substrates are found to be highly resistant to oxidative attack, and possess anti-corrosion characteristics.
However, these processes consume extremely high amounts of energy and are difficult to control and impractical.
Research data in phosphorus implantation have been reported to show improved corrosion resistance of stainless steel. However, this process requires expensive and sophisticated processing equipment and at the present time, is impractical for use in production.
Surprisingly, it has been found according to the present invention that a zinc/silicon/phosphorus coating can provide a solution to all of the above problems. The zinc/silicon/phosphorous coating has a low coefficient of friction, equivalent to that provided by cadmium. The coating adheres well and is not destroyed when subjected to full torque and tensile loading. Further, only a layer of 0.2 to 0.3 mil thickness is sufficient to provide excellent corrosion resistance. The coating can be deposited on any conductive substrate, including but not limited to aluminum, titanium, chromium, stainless steels and alloys, high strength metals used by the aerospace industry. Moreover, the coating eliminates galling problems associated with high strength alloy steels.
Another area where the present invention has application is in the plating of difficult to plate metal substrates, such as aluminum, titanium and stainless steel. Up to the present, it is difficult to obtain good adhesion to these metal substrates because of the presence of a film of metal oxide on the surface. The metal oxide film can be removed by immersion in acidic or alkaline solutions. However, the oxide film re-forms immediately when the metal substrate is removed from the de-oxidizing solution. Although methods to improve adhesion are available, these generally involve additional processing steps and increased production costs.
For example, in the production of magnetic recording discs, aluminum is provided with a layer of electroless nickel to provide adhesion for subsequent deposition of a magnetic coating. However, nickel is expensive and it provides a hard surface which is difficult to grind smooth for subsequent processing.
Although stainless steel is easier to plate than aluminum, the formation of an adherent coating by electrodeposition is extremely difficult. In fact, stainless steel is frequently used as the substrate when it is desired to form a coating which can be subsequently removed from the substrate for mechanical testing. The process for electrodepositing a coating on stainless steel involves several pickling steps prior to electrodeposition and, even then, a
Titanium is extremely difficult to plate because of the formation of an extremely stable oxide film, which prevents the formation of an adherent coating. Therefore, the pickling step to remove this stable oxide film is even more crucial, and hydrofluoric acid is often used. Clearly, this is undesirable because of the corrosive nature and the danger of this solution.
It is desirable, therefore, to provide electrodeposition methods for the plating of these metals.
Attempts to electroplate silicon have been made in research laboratories. Unfortunately, these processes require the use of extremely high temperatures or of non-aqueous solvents. The former results in high energy consumption, while the problem of water removal and waste disposal has to be overcome with non-aqueous solvents.
Recently, three patents have issued describing methods of producing inorganic multi-metal polymeric complexes containing hydrophosphide groups in aqueous solutions. U.S. Pat. No. 4,029,747 described a polymeric-metal complex of a non-alkaline metal and an alkali metal in ammonia, for example silicon-sodium in ammonia and aluminum/sodium/calcium complex in ammonia. U.S. Pat. No. 117,088 describes an inorganic polymeric metal complex of non-alkaline metal of Group I-VIII, an alkali metal and a phosphorous compound in aqueous solutions. Specifically, Example 11 discloses a silicon-sodium-phosphorus polymeric complex. U.S. Pat. No. 4,117,099 describes an inorganic polymeric metal complex of non-alkaline metal of Group I-VIII, an alkali metal and a sulfur containing compound.
It is indicated that the polymeric solutions may be useful in plating. Specifically U.S. Pat. No. 4,029,747 suggests that the complexes may be used to plate silicon. U.S. Pat. No. 4,117,088 does not disclose or suggest the plating of silicon, and it was found that a solution prepared according to Example 11 of U.S. Pat. No. 4,117,088 did not produce an electrodeposit of silicon. Surprisingly, the applicants found that when zinc ions were added to the silicon-containing solutions, silicon was co-deposited with zinc. It is to be noted, however, none of the disclosures in these patents suggest that a co-deposit of silicon and phosphorus with zinc by electrodeposition can be obtained.
It is an object of the present invention to provide an economical and practical method to improve the resistance of metals to corrosion, wear, galling and stress corrosion cracking.
It is another object of the present invention to provide a method of electrodepositing a zinc/silicon/phosphorus coating on metal to improve the resistance of the metal to corrosion, wear, galling and stress corrosion cracking.
It is a further object of the present invention to provide an aqueous composition to electrodeposit a zinc/silicon/phosphorus coating on metals including difficult to plate metals, such as aluminum, stainless steel and titanium.
It is another object of the present invention to electrodeposit reliably silicon-comprising coatings.
It is a further object of the present invention to provide a metallic article having a surface coating comprising zinc/silicon/phosphorus.
BRIEF DESCRIPTION OF THE INVENTION
According to the present invention, methods and aqueous compositions suitable for electrodepositing a co-deposit of zinc/silicon/ phosphorus on various metal substrates have been developed.
The methods comprise preparing an aqueous solution suitable for electrodeposition, comprising about 0.5 g to about 50 g per liter of zinc, about 0.01 g to about 10 g per liter of silicon and about 10 g to about 250 g per liter of phosphorus.
The aqueous solution is prepared either by contacting zinc and silicon metals in the presence of each other with a phosphorus containing acid and alkali metal hydroxide or ammonium hydroxide, or by contacting the zinc and silicon metals with said acid and alkali in separate vessels and mixing the reaction product after the completion of the individual reactions.
Preferably the pH of the solution for electrodeposition is in the range of about 2 to about 5 or about 8 to about 14. More preferably, the pH is in the range of about 2.5 to about 4 and about 10 to about 12.
Further, it is preferred that the reaction is allowed to proceed for about 16 hours.
The aqueous solutions prepared according to the present invention is viscous.
The metal substrate to be coated by electrodeposition is cleaned and immersed in a solution prepared as decribed above. The metal substrate is connected as the cathode.
Using a current density of about 1 A/dm 2 (amps/square decimeter) to about 7 A/dm 2 for about 20 minutes, a coating of about 10 microns on the metal substrate with at least about 70% by weight of zinc, at least about 0.10% by weight of silicon and at least about 0.5% by weight of phosphorus is obtained.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a typical EDX spectrum of the surface of the steel subtrate after electrodeposition using the solution according to the invention. The spectrum shows the presence of zinc, silicon and phosphorus in the surface layer of the steel.
FIG. 2 is a scanning electron microscope picture of the surface with zinc/silicon/phosphorus coating.
FIG. 3 is a graph plotting torque against loss of weight of the block in milligrams. This shows the degree of wear of the objects tested. The straight line shows the rate of wear of a coated block against an uncoated-ring. The curve shows the rate of wear of an uncoated block against an uncoated ring.
FIG. 4 is a graph plotting degree of stress versus time-to-failure in hours for coated and uncoated casing material after these have been subjected to various stress levels. The upper curve is the result obtained for a coated casing, the lower curve is the result obtained for an uncoated casing.
FIG. 5 is a graph comparing the corrosion rate (mpy=mils per year) of coated and uncoated metal specimens made of AISI 410, 9Cr-1MO and AISI 4130, steels.
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, aqueous solutions can be used to electrodeposit a coating of zinc/silicon/phosphorus on a metal substrate.
By using the solution prepared according to U.S. Pat. No. 4,117,088, it was found possible to electrodeposit zinc onto a metallic substrate. This was expected because zinc may be electroplated using a variety of known electrolytic zinc-containing solutions.
However, when the teaching described in U.S. Pat. No. 4,117,088 was used to prepare silicon-containing solutions, silicon-containing species were not electrodeposited. See Example 4.
Surprisingly, however, applicants found that when zinc-containing solutions were added to silicon-containing solutions, silicon was routinely and reliably co-deposited with zinc on the cathode. It was further found by applicants that when solutions are prepared according to the present invention, a co-deposit of zinc, silicon and phosphorous was formed on the surface. See Example 12. Thus, a composite deposit containing zinc, silicon, and phosphorus was formed by electrodeposition from these solutions.
Because a deposit containing these three species was unknown prior to the present invention, the properties of such a deposit were completely unknown. It was surprising to find superior galling-resistant, wear-resistant, corrosion-resistant and stress corrosion-resistant properties.
The solution according to the present invention comprises about 0.5 g to about 50 g per liter of zinc, about 0.01 g to about 50 g per liter of silicon and about 10 g to about 250 g per liter of phosphorus. Preferably, a solution for electrodepositing a zinc/silicon/phosphorus coating comprises about 1 g to about 20 g per liter of zinc, about 0.1 to about 10 g per liter of silicon and about 40 g to about 200 g per liter of phosphorus. More preferably, the solution for electrodeposition comprises about 10 g to about 20 g per liter of zinc, about 0.5 to about 2 g per liter of silicon and about 50 g to about 120 g per liter ofphosphorus.
The aqueous solution is prepared either by contacting zinc and silicon metals with a phosphorus-containing acid and an alkali metal hydroxide or ammonium hydroxide in the presence of each other, or by contacting the zinc and silicon metals with said acid and alkali in separate vessels and mixing the reaction product after the completion of the individual reactions. Preferably, the silicon and the zine metal are in the form of large granules.
In the first method, the aqueous solution is prepared by contacting silicon metal in the presence of zinc in an aqueous solution of a phosphorus-containing acid and adding an alkali metal hydroxide or ammonium hydroxide in increments until the pH is in the range of about 1.5 to about 14. The solution is allowed to react for from about 16 hours to a few days without stirring. Alternatively, the solution may be prepared by contacting silicon metal in the presence of zinc with concentrated alkali metal hydroxide solution and then adding a solution of a phosphorus-containing acid in increments until the pH is in the range of about 1.5 to about 14. The solution is then allowed to react for from about 16 hours to a few days without stirring. In both cases, the reaction continues until all the metal has dissolved, or, as is more common, the product solution is decanted from the excess metal when the desired metal ion concentration in the product solution is reached.
In the second method, zinc and silicon concentrated solutions are prepared separately, and the solutions are mixed after preparation. The separate concentrated solutions are first prepared by contacting zinc metal and silicon metal in separate vessels with a phosphorus containing acid and adding increments of an alkali metal or ammonium hydroxide. Alternatively, the separate solutions can be prepared by contacting zinc metal or silicon metal with concentrated alkali metal hydroxide or ammonium hydroxide and then a phosphorus containing acid in increments. The pH of the mixture should be in the range of about 1.5 to about 14. The reaction is allowed to proceed for from about 16 hours to a few days without stirring. Again, the reaction continues until all the metal has reacted, or the product solution is decanted from the excess metal when the desired metal ion concentration in the product solution is reached. The zinc-containing solution is then mixed with the silicon-containing solution such that the ratio of zinc to silicon is in the range of about 8:1 to about 30:1.
The addition of alkali metal hydroxide to a phosphorus-containing acid or a phosphorus-containing acid to alkali metal hydroxide generates heat and raises the solution temperature. During the contacting of the metals with a phosphorus-containing acid and alkali metal hydroxide, the solution temperature should not exceed the boiling point of the solution and, preferably, should not exceed 80° C. The temperature can be controlled by controlling the rate of addition of the phosphorus-containing acid to the alkali mixture, the rate of addition of alkali metal hydroxide to the acid mixture, or by conventional cooling apparatus.
The alkali metal hydroxide is selected from a group consisting of sodium, potassium and lithium, preferably sodium or potassium. The phosphorus containing acid may be phosphorus acid, phosphoric acid or orthophosphoric acid, preferably orthophosphoric acid.
Alternatively, silicon metal is reacted with concentrated aqueous alkali metal hydroxide or ammonium hydroxide. The resulting product is then combined with a solution of zinc in phosphoric acid and allowed to react without stirring for several days.
Electrodeposition is carried out at a pH in the range of about 2 to about 14, preferably at a pH of about 2 to about 5 or about 8 to about 14, more preferably at a pH in the range of about 2 to about 4 or about 10 to about 12 and most preferably at a pH in the range of about 2.5 to about 3.5. The pH of the solution prepared according to the methods described above is adjusted by using a concentrated alkali metal hydroxide solution or concentrated phosphoric acid solution.
The deposition is carried out by electrodeposition. Insoluble anodes such as carbon or precious metal coated titanium (DSA anodes from Diamond Shamrock) as well as soluble anodes, e.g. zinc metal, may be used to co-deposit zinc/silicon/phosphorus from the solution of the present invention. The ratio of the area of the anode to the cathode should be about 1:1 or higher. The anode and cathode are placed about 7 cm to about 18 cm apart, preferably 10 cm apart. The current density is in the range of about 0.5 A/dm 2 to about 10 A/dm 2 , preferably about 1.6 A/dm 2 to about 4 A/dm 2 . Plating current densities higher than 10 A/dm 2 are possible when special agitation techniques are used, such as ultrasonic stirring or jet impingement.
Electrodeposition from a solution according to the present invention shows a cathodic efficiency of about 75%. At an optimium current density of about 3.3 A/dm 2 a layer of about 10 micron is deposited on a metal substrate in about 15 minutes. The pH and specific gravity of the solution remains almost unchanged even when the solution is depleted down to 50% of the amount of zinc, silicon or phosphorus initially present.
The depleted zinc and silicon in solution is replenished by addition of concentrated solution of zinc and silicon, or when a zinc anode is used, by addition of a concentrated solution of silicon. The required amount of zinc or silicon can be determined by an analysis of the amount of zinc or silicon remaining in the depleted solution. This analysis can be made either by wet or instrumental methods.
An electrodeposition bath according to the present invention has very good macro throwing power. However, for metal parts with intricate or special shapes, conforming anodes or auxiliary anodes may be required to provide sufficient micro throwing power.
The zinc/silicon/phosphorus coating of the present invention formed by electrodeposition is matte gray in color. If desired, the appearance of coated parts may be improved by dipping into a solution of about 0.5 to 1% nitric acid, rinsed with water and dried. It has been found the coated surface treated with nitric acid is whiter and smoother. The coated parts may also be subjected to chromate conversion coating process to provide a clear blue or gold finish. The chromate conversion coating process further improves the corrosion resistance of the parts with a zinc/silicon/phosphorus coating.
Parts which have been subjected to the electrodeposition process according to the present invention were analyzed by electron dispersive x-ray analysis (EDX) to determine the presence of zinc, silicon and phosphorus on the surface of the metal part. In this method, a selected area of the specimen is bombarded with electrons at a typical accelerating voltage of 10 to 30 Kev. The electron bombardment causes the emission of an x-ray spectrum of the characteristic x-ray lines of each of the elements present on the surface of the specimen.
It is believed that the coating should comprise at least about 70% by weight of zinc, at least about 0.1% by weight of silicon, and at least about 0.5% by weight of phosphorus. Preferably, the ranges should be 88% by weight of zinc, 9% by weight of silicon and 3% by weight of phosphorus. It is extremely difficult to measure the composition of surface coatings. EDX is a good compromise combining good sensitivity with reasonable cost and can be used for routine analysis. The coating is believed to contain oxygen in the form of metal oxides and of oxygenated-phosphorus moieties; however, oxygen is not detected by EDX. The EDX analysis is usally reported as percent by weight of zinc, silicon and phosphorus with a total of 100%, although it is actually the weight ratio of zinc to silicon to phosphorus that is measured.
The solutions for electrodeposition may be prepared in various ways as shown in the following examples.
EXAMPLES FOR POLYMER PREPARATION
EXAMPLE 1
An electroplating solution was prepared as follows: 50 g of silicon granules (20 mesh, 99.999%) was mixed with 252 ml H 3 PO 4 (85%) and 520 ml deionized water in 1 liter beaker. The temperature of the solution was maintained at 30°-35° C. in an ice bath. 135 g of sodium hydroxide pellets were added in increments of 10 g every 15 minutes with gentle stirring. The total amount of time required is about 3.5 hours. 8 g of zinc granules were added to the solution. The solution was allowed to react without stirring for 5 days. The pH of the solution was found to be 2.97. A current density of 3.2 A/dm 2 was used to electrolytically co-deposit a coating on a steel substrate. A 10-micron layer of Zn/Si/P was deposited on the surface in about 20 minutes. An electron dispersive X-ray analysis (EDX) indicated the characteristic X-ray lines of zinc, silicon and phosphorus in the coating.
EXAMPLE 2
Premix A was prepared by mixing 250 g of zinc with 126 ml H 3 PO 4 (85%) and 360 ml of deionized water in a 1-liter beaker. The temperature of the solution was maintained at 30°-35° C. in an ice bath. The mixture was allowed to react for 1 hour. 85 g of potassium hydroxide (KOH) was added with gentle stirring in increments of 3 g every 15 minutes. The amount of time taken was about 61/2 hours. The solution was allowed to react for 5 days.
Premix B was prepared by mixing 50 g of silicon granules with 126 ml H 3 PO 4 (85%) and 360 ml of deionized water in a 1-liter beaker. The temperature was maintained at about 30°-35° C. by immersing the beaker in an ice bath. 115 g of KOH pellets in increments of 5 g every 15 minutes was added to the solution with gentle stirring. The solution (Premix B) was allowed to react for 5 days.
Premix A and Premix B were then mixed in a ratio of 1:1 by volume.
This mixture with a pH of 2.92 was used to coat a steel substrate by electrodeposition. The plated surface was then subjected to analysis by EDX which showed the presence of 82.2% by weight of zinc, 3.8% by weight of silicon and 14.0% by weight of phosphorus. The ratio of zinc: silicon:phosphorus is 82.2: 3.8: 14.0.
EXAMPLE 2A
The above Premixes A and B were mixed in a ratio of 1:3 and used to electrodeposit a coating on a steel substrate. The pH of the solution was 3.25. EDX analysis of the coating revealed the presence of 72.6% by weight zinc, 8.8% by weight of silicon and 18.6% by weight of phosphorus. The ratio of zinc: silicon: phosphorus is 72.6: 8.8: 18.6.
EXAMPLE 3
45 g zinc pellets, 5.7 g of granular silicon was mixed with 252 ml H 3 PO 4 (85%) and 720 ml deionized water in a 1-liter beaker maintained at the temperature of 30°-35° C. 170 g of KOH pellets were added to the mixture in increments of 7 g every 15 minutes over a period of 61/2 hours.
A 100 ml solution of 5.7 g Si and 40 g KOH were reacted for 4 hours. This solution was slowly added to the zinc/silicon/phosphoric acid mixture and allowed to react for 5 days.
A steel substrate was coated by electrodeposition in the above solution with a pH of 3.25. The surface of the plated substrate was analyzed by EDX and found to contain silicon, phosphorus and zinc.
EXAMPLE 4
An electroplating solution in accordance with U.S. Pat. No. 4,117,088 was prepared as follows: 85 g of silicon lumps were washed with hydrochloric acid solution (HCl diluted 1:1 with water). The silicon was then filtered from the solution and added to a mixture of 50 ml of 85% H solution and 200 ml of deionized water in a 1 liter beaker. The reaction was allowed to proceed for 2 days at 60° C. After this period, the silicon was filtered, and the concentration of silicon-containing species remaining in the solution was 44 g/l and the pH was 11.2. The pH of the solution was adjusted to 2.9 and the silicon concentration was adjusted to 1.3 g/l by adding 85% H 3 PO 4 solution. A current density of 5 A/dm 2 was then used to pass a current through the solution using a copper cathode and a pyrolytic graphite anode. An EDX analysis indicated no characteristic X-ray line of silicon, and it was concluded that silicon-containing species were not electrodeposited from the solution.
EXAMPLE 5
Premix A was prepared by mixing 150 g of silicon powder (20 mesh, 99.999%) with 1500 ml of concentrated ammonium hydroxide. Ammonia gas was bubbled slowly through the solution. 125 g NaOH pellets were added to the solution over a period of 3 hours in increments of about 3.5 every 5 minutes. The temperature of the reaction is controlled at 30°-5° C. for 48 hours.
Premix B was prepared by reacting 30 g of zinc powder in 250 ml of H 3 PO 4 (85%) and 750 ml of deionized water. The solution is gently stirred for about 5 hours until all of the zinc has dissolved.
The electroplating solution is prepared by mixing Premix A and Premix B in a ratio of 1:3 with stirring.
EDX Analysis of the surface of a steel substrate electroplated in the above solution at pH 2.5 indicates the presence of 9% by weight of silicon, 3% by weight of phosphorus and the balance as zinc.
EXAMPLE 6
Solutions were prepared in accordance with the methods described. The results are indicated in the following table.
______________________________________ Solution Composition CoatingMe- Spec. Zn P Si Compositionthod pH Gravity g/l g/l mg/l Zn Si P______________________________________ Ex-am-ple1 2.97 1.250 7.4 110 240 + + +2 2.92 1.154 8.3 70 60 + + +2A 3.25 1.158 4.1 60 90 + + +3 3.25 1.148 5.2 60 2.250 + + +4 2.48 1.122 14.5 51 625 + + +______________________________________
EXAMPLE 7
10 liters of H 3 PO 4 (85%) and 10 liters of water were added to a 5 gallon reactor. Cooling water (10° C) was run in the cooling water bath until the acid mixture has cooled to less than 25° C. 9 Kg of zinc metal granules were added to the acid mixture and allowed to react for 15 minutes. 168 grams of NaOH pellets were added every 15 minutes until 4.2 Kg total has been added. The solution mixture was controlled at 35° C. (30°-40°) for four days. After which the clear solution containing the solubilized zinc is poured off.
A silicon premix solution was prepared as follows:
400 g granular silicon, 300 ml deionized water and 300 ml phosphoric acid (85%) were added to a 1-liter beaker. 30 g of NaOH pellets were added initially. A total of 480 g NaOH added in increments of 30 g every 15 minutes. The reaction temperature was controlled to 50° C. and the reaction carried out for 24 hours. The solution was diluted with water back to 1 liter. The clear silicon premix solution was poured off.
600 ml of silicon premix solution was slowly mixed into 20 liters of the zinc premix solution.
A steel substrate was electrocoated in the above solution. The surface analysis of the coating by EDX revealed zinc, silicon and phosphorus.
EXAMPLE 8
A zinc premix solution was prepared: 980 kg of zinc nuggets were added to a stainless steel reactor. 1860 kg of 85% phosphoric acid and 1060 liters of water were mixed into the reactor with stirring. The cooling water of the reactor was turned on to maintain a temperature of 38° C. 23 kg. of caustic soda pellets were added to the reactor. Agitation was applied until the temperature was below 38° C. When a minimum of 15 minutes has passed, an additional 23 kg. of caustic were added and agitated. The addition and agitation repeated until a total of 460 kg. of caustic soda pellets have been added. The agitator was turned off and the solution was allowed to react for at least 84 hours. The clear solution was drained into drums.
The silicon premix was prepared as follows:
190 kg. of silicon granules were added to the polyethylene tank with 425 liters of water. 235 kg. of 85% phosphoric acid were mixed in the tank. 23 kg. of caustic soda pellets were added every 15 minutes until a total of 230 kg. have been added. The reaction temperature was maintained at 52°-74° C. by running cooling water through the reactor coils. The batch was held at 52°-74° C. for 24 hours. The clear solution was drummed out.
The plating solution was prepared by mixing the zinc premix solution and the silicon premix solution in a ratio of 12:1 with stirring. Analysis of the coating of a steel substrate using electrodeposition in the above solution indicates 94.7% by weight of zinc, 3.7% by weight of silicon and 1.6% by weight of phosphorus. The ratio of zinc: silicon: phosphorus is 94.7: 3.7: 1.6.
Metal parts can be coated by electrodeposition using any one of the above solutions at a pH in the range of about 2 to about 14, preferably about 2 to about 5, or about 8 to 14, the pH being adjusted with concentrated phosphoric acid or alkali metal hydroxide. The electroplating process is carried out at ambient room temperature, i.e., in a range of about 10° to 32° C. The metal substrate to be coated is connected as the cathode. The anode may be insoluble, e.g. carbon or precious metal coated titanium, or soluble, e.g. zinc. Generally the surface area of the anode to the cathode should be in a ratio of 1:1 or higher, placed about 7 cm to 18 cm apart preferably about 10 cm apart. The current density applied is in the range of about 0.5 to about 10 A/dm 2 , preferably about 1.6 A/dm 2 to 4 A/dm 2 . At about 3.2 A/dm 2 , the amount of time needed to deposit a 10 microns layer is about 15 to 20 minutes.
The metal parts may be made of various metals selected from the group comprising steel, stainless steel, copper, zinc, aluminum and titanium.
EXAMPLE 8A
770 grams of zinc metal nuggets and 19 grams of granular silicon metal were added to a reactor containing 1 liter of water. 400 ml of 85% phosphoric acid were slowly added to the mixture with constant stirring. The solution was allowed to proceed for 30 minutes. Then, 38 grams of sodium hydroxide was added every 30 minutes and the reaction was allowed to proceed with constant stirring. When the pH reached about 3, feed of NaOH was stopped. The reaction was allowed to proceed for 3 to 4 days. The solution was removed by decantation. This solution showed 11 g/1 of zinc, 28 mg/1 of silicon and 90 g/1 of phosphorus.
A steel substrate was electrodeposited in the above solution. The surface analysis of the coating by EDX revealed 0.1% by weight of silicon, 0.5% by weight of phosphorus and 99.4% by weight of zinc.
EXAMPLE 9
2.3 kg of zinc metal nuggets was added to a reactor with 3 liters of water, and 57 grams of granular silicon metal was added to the mixture. 1.2 liters of 85% phosphoric acid were slowly added with constant stirring over a 1/2 hour period. The reaction of phosphoric acid and zinc was allowed to proceed for another 1/2 hour. 114 grams of KOH were added every 30 minutes and reaction allowed to proceed with constant stirring and controlling the temperature of the reactor to between 21°-32° C. When the pH reached about 2, feed of KOH was stopped. The reaction was allowed to proceed for 3 to 4 days with the temperature at 90° C. or lower. As zinc granules reacted and went into solution the pH gradually climbed to about 3.5. After 3-4 days, the solution was removed by decantation. This solution was used to electrodeposit a steel substrate. EDX analysis of the electrodeposited surface detected the presence of zinc, silicon and phosphorus.
EXAMPLE 10
400 ml of zinc concentrate as prepared in example 7 was added to 400 ml of D.I. water. 50% NaOH solution was added to raise pH to 7.0. Then 20 ml of the silicon concentrate as prepared in Example 7 was added. The pH was adjusted with 50% NaOH resulting in pH of 7.0 with a total volume of 1 liter.
Some white precipitate slowly settled out. Analysis showed zinc to be 0.20 g/1. A current density of 3.2 A/dm 2 was applied to a cathode immersed in the clear liquid for 15 minutes. A very thin white deposit was observed.
EXAMPLE 11
25 ml of 50% NaOH was added to 800 ml of D.I. water. 20 ml of silicon concentrate as prepared in Example 7 was added to the alkali water. Then 40 ml of zinc concentrate as prepared in Example 7 was slowly added with stirring. A white precipitate slowly settled. The volume was adjusted to a total of 1 liter. pH of this solution was 13.5. The soluble zinc measured at 1 g/l. A current density of 3.2 A/dm 2 was applied for 15 minutes to the cathode immersed in this clear solution. A smooth dark gray deposit resulted.
EXAMPLE 12
A solution was prepared by the method described in Example 11 of U.S. Pat. No. 4,117,088:
422.1 g of high purity silicon lumps were mixed with 800 g deionized water. 200 g of sodium hydroxide pellets were added to the solution. The reaction temperature was kept at 53° C. for dissolution of silicon. A slow feed, drop by drop, of 85% phosphoric acid was added to the reaction vessel. The phosphoric acid feed was stopped when the pH reached about 12. The reaction was allowed to proceed for 14 hours. Heat was removed and more phosphoric acid was added. The reaction was allowed to react overnight. The pH was 10.8. The solution was used to plate on a steel panel. There was no visual coating observed. EDX also did not detect any silicon on the panel.
A zinc premix solution was prepared according to the procedure described in Example 8. This zinc premix solution was added to the silicon solution described above.
The plating solution thus prepared deposited a coating on the steel substrate. Analysis of the coating by EDX indicates the presence of zinc, silicon and phosphorus.
Examples Showing Improved Corrosion Resistance
EXAMPLE 13
Five test cups made of iron were coated by electrodeposition in a solution prepared according to the procedure described in Example 9.
The five coated cups were cleaned by successive dipping and washing in Hexane and allowed to air dry. Three of the cups were dipped in Ferrocote 366 oil. All of the cups were placed in a humidity cabinet and subjected to a standard 30-day humidity cycle. After 30 days, the cups were removed and visually inspected.
The coated cups, both with and without Ferrocote oil coating, successfully passed the 30-day humidity cabinet test. There was no evidence of any iron rusting on the five cups. Several of the coated cups did show a soft white deposit in several areas. Under normal conditions and using the Ferrocote 366 mixture, some corrosion would have been expected. This did not occur with the coated cups.
The electrodeposition appears to have pacified the iron surface, since no corrosion was observed-even in areas where the surface coating was badly scratched.
EXAMPLE 14
Samples of 11/8" diameter×8" ASTM A-193 B7 stud bolts with ASTM A-194 grade 2H nuts ware electrolytically coated to provide a zinc-silicon-phosphorus coating layer of 8 microns in thickness. The bolts and nuts were torqued to 100% of minimum yield strength in a simulated flange fixture incorporating a strain gauged load cell for load monitoring. After this, the five bolts and nuts were placed in an ASTM B-117 salt fog test chamber for corrosion testing. Two bolts with nuts were removed after 300 hours; one bolt with nut was removed after 700 hours; another bolt with nut was removed after 1000 hours and the final bolt was removed after 1350 hours. Results of the salt fog tests were as follows:
After 300 hours, no visible corrosion product was observed.
After 700 hours, no visible corrosion was observed.
After 1000 hours, slight surface corrosion was present; however, pitting of the steel substrate was not observed.
After 1350 hours, the bolt threads were filled with salt residue and/or corrosion products. The residue was easily removed, and no gross deterioration of the fastener was observed. There was some minor corrosion pitting. However, on testing, it was found that the strength of the fastener has not been reduced by the minor corrosion found.
EXAMPLE 15
Four 2"×3" 1010 low carbon steel panels were electrodeposited in a solution described in Example 7. An acid zinc coated 1010 steel was chromated and used as a control panel. All five panels were exposed to salt fogging as described in ASTM B117 test procedures, for 1,000 hours or until there was sufficient apparent degradation to warrant close examination. After an exposure of 700 hours, the control panel exhibited apparently severe corrosion over 90% of its surface, while the Zn/Si/P coated panels were discolored over about 70% of the surface areas. Upon close examination, the nature and extent of the corrosion at the surfaces were found to differ. On the control panel, numerous pits, up to about 2.5 mm deep, were found. Further, wherever red iron oxide was observed on the surface, the underlying steel showed signs of pitting due to corrosion. By contrast, on the Zn/Si/P coated panels, no pits deeper than about 5.3 microns were found. Many areas of the coating were stained red by iron oxide, but there was no corrosion damage of the steel substrate. It appears that corrosion products from small areas made it appear as if large areas have been severely affected.
Examples Illustrating Improved Wear Resistance
EXAMPLE 16
A Timken block was coated electrolytically in a solution described in Example 9. The lubricity measurement was performed using the coated block and an uncoated ring, which were immersed in 15W-40 grade motor oil during the test. The ring and block did not seize at the maximum torque of the Timken Tester, i.e., 410 in.-lb., after which the test was terminated. Results are shown in FIG. 3, a graph plotting torque vs. weight loss.
EXAMPLE 17
Three sets of Timken blocks and rings were tested on the Timken Tester and were identified as follows:
#1 Uncoated ring and block
#2 Coated ring--uncoated block
#3 Coated ring and block
The pieces were electrolytically coated in a solution described in Example 1.
The loss of weight of the block in milligrams was plotted against the torque meter reading, giving a visual indication of the rate of wear and the torque value at which the scoring of parts observed. No scoring of any of the three samples was observed at 320 in.-lbs. Scoring of the uncoated ring and uncoated block started to appear at 350 in-lbs. The coated ring and uncoated block showed a steady rate of wear but did not score even at the maximum torque of the Timken instrument. The coated ring and coated block also showed a steady but higher wear rate. There was some evidence of scoring at the maximum torque of 410 in-lbs.
Examples Illustrating Improved Galling Resistance
EXAMPLE 18
Four Timken blocks were coated by electroplating from a solution decribed in Example 9. They were tested on the Timken Test Machine.
The four treated blocks and one untreated block, for comparison, were tested on the Timken Test Machine using the "oil-off" procedure. All tests were performed using a standard untreated T48651 test cup.
The cup and block were mounted in the Test Machine and flooded with lubricant (Mobil Jet II oil, 100° F. inlet temperature). The Test Machine was started, and the speed adjusted to 1200 rpm.
Loads were added at a rate of one pound per minute until the total weight was ten pounds. A baseline running torque was established.
After a ten minute "run-in", the oil flow was stopped and residual oil at the cup-block interface was purged using an air nozzle.
The machine was then run until the torque had increased to ten inch-pounds above baseline or reached a total running time of 50 minutes.
The "oil-off" test blocks (four treated and one untreated) were started with an initial no load running torque of 12 lb-ft/in. with a range of 19 to 22 lb-ft/in. The torque remained fairly constant during the ten minute "run-in" portion of the test.
Almost immediately upon removal of the oil flow, there was a drop in running torque of one to two lb-ft/in. in all of the runs. The untreated block exceeded the 10 lb-ft/in. criteria within 11/2 minutes and was terminated. The treated blocks ran an average of 14.5 minutes under the no load condition. None of the wear patterns on the treated blocks reached the depth or width observed on the untreated block.
EXAMPLE 19
Four standard A.P.I. (American Petroleum Institute) L-80 couplings (23/8' & 27/8' OD) were electrolytically coated in solution as described in Example 1. They were doped with regular A.P.I. pipe on a regular "buck-on" machine to 800 lbs. torque and standard A.P.I. stand off. The couplings were then removed and inspected. No galling was apparent on the pin or the coupling. This operation was repeated eight times without any observed galling.
EXAMPLE 20
A 23/8" L-80 coupling and a pin were coated by electrodeposition in a solution as described in Example 2. The coupling and pin were doped and buck on and off a L-80 pipe 4 times. No apparent galling or damage to threads was observed.
EXAMPLE 21
A 27/8" coated coupling and coated pin were plated from a solution described in Example 2. They were undoped and bucked on and off one time with no apparent galling. Coupling was overtorqued on the second run and resulted in severe galling.
EXAMPLE 22
A set of threaded components 1 5/16 through 18 UNEF-2 were plated from the solution described in Example 7. The coated set was subjected to torsional/loading to about 120 ft. to the pound. There was no thread galling when the components were unscrewed.
A set of uncoated set was loaded to about 40 ft. to the pound. When the uncoated component was unscrewed, the threads galled. It appeared that the coefficient of friction had been reduced for the coated components.
EXAMPLE 23
Five samples of 11/8" diameter×8" long ASTM A-193B7 stud bolts with ASTM A-194 grade 2-H nuts were plated with Zn/Si/P coating of 8 microns thick. The bolts and nuts were mechanically tested by applying a torque to 100% of minimum yield strength. After this, the five bolts and nuts were placed in an ASTM B-117 salt fog test chamber for corrosion testing. Two bolts with nuts were removed after 300 hours. The nuts turned freely by hand along the entire length of the bolt. One bolt with nut was removed from the fog chamber after 700 hours. The nut also turned freely by hand along the entire length of the bolt. The set of bolt and nut removed after 1000 hours had a prevailing break-out torque on the order of 20 to 35 ft. lbs. After starting, the nut could be turned easily by hand. The final bolt threads removed after 1350 hours were filled with salt residue and/or corrosion products. The nut was easily removed from bolt. The nut could not be threaded on other areas of the bolt which were not protected by the nut during testing.
Examples Illustrating Improved Stress Corrosion Cracking Resistance
EXAMLE 24
ASTM A-194 Grade 2-H thread stud bolts (11/8"×8") steel were coated electrolytically in a solution prepared according to the procedure described in Example 8, using a current density of 3.2 A/dm 2 . Two test blocks of hardened 4140 steel, in which 11/4" holes had been bored, were clamped together. Four (4) of the bolts were installed in the test block at 1,800 ft. of torque which create 85,000 pounds load. The test block created a stress length of 4" in each of the four bolts. The test assembly was then wetted with tap water and placed on the ground outside for 14 days. There was no evidence of stress corrosion cracking during this period. The assembly was then installed in a 100% condensing humidity cabinet at 35° C. and remained there for 9 days. The assembly was then removed and returned to the outside environment for 14 days. No indication of any cracking in the material was observed.
EXAMPLE 25
Threaded stud bolts made of 4140 Steel were coated electrolytically in a solution prepared according to the procedure described in Example 7. An attempt to promote stress corrosion cracking failure was done by dissembling the fixture described in Example 24, removing the studs, greasing the threads, and re-assembling the fixture using the original bolt which had been previously exposed in Example 24, and retorquing until the nut threads galled and further torquing could not be accomplished. The bolts did not crack or fail and the test was suspended.
EXAMPLE 26
Eight tensile tests were conducted on P-110 casing steel (yield strength, 128 psi) in accordance with NACE Standard TM-01-77. Four of these specimens were coated by electrodeposition in a solution described in Example 8. The other four specimens remained uncoated. Samples were prepared and tested using the NACE Standard.
During start-up, the NACE solution (5% NaCl, 0.5% Acetic Acid in distilled water saturated with H 2 S at 75° F. and 15 psi) in which the coated casing were immersed turned milky when H 2 S was introduced. The solution with the uncoated specimens remained clear. It appeared that H 2 S may have reacted with the zinc/silicon/phosphorus coating to cloud the solution.
Four stress levels were tested. The results are shown below:
______________________________________Stress (%) Specimen Time to Failure (hrs)______________________________________80 coated 7.380 uncoated 1.660 coated 13.560 uncoated 2.540 coated 21.740 uncoated 4.620 coated NF20 uncoated 20.2______________________________________ NF = no failure
It is evident that the coating extended the time to failure of this particular material. Consistently, at all stress levels examined, the coated specimens had longer time-to-failure than uncoated specimens. See FIG. 4.
EXAMPLE 27
Weight loss corrosion coupons of three standard steels: AISI 4130, 9Cr-1Mo, and AISI 410 were exposed to NACE solution (5% NaCl, 0.5% Acetic acid in distilled water saturated with H 2 S at 75° C. and 15 psi). Samples were exposed for a period of thirty days. Corrosion rates, as measured by weight loss, were calculated from specimen weight measurements made before and after exposure. Sample dimensions were 1-inch×2-inches×1/16-inch. Multiple samples of materials were coated with Zn/Si/P coating. All coated samples were tested simultaneously. Uncoated samples were exposed to NACE solution in a separate vessel.
The results of the corrosion tests are shown in FIG. 5. For AISI 4130, the average corrosion rates for the coated samples were approximately the same as the uncoated AISI 4130. The average corrosion rates for the coated 9Cr-1Mo and AISI 410 were generally lower than those found for the uncoated samples. pH measurements of the solution made after the completion of the test revealed that the pH of the solutions from the two tests involving the coated and uncoated samples were approximately the same (pH=3.7). This suggests that any differences in corrosion behavior were not the result of pH differences that may have been caused by the coating or the corrosion products.
EXAMPLE 28
A single tensile test was conducted in NACE solution by methods in accordance with NACE Standard TM-01-77. The material was P-110 (Y.S.=128 psi). The specimen was coated with Zn/Si/P by electrodeposition and stressed to 80% of the material yield strength.
The time-to-failure of the coated tensile specimen of P-110 was 15.0 hours. This is substantially longer than those found for the uncoated specimen and coated specimen tested in Example 23 at 80 percent of yield stress.
Examples Illustrating Adhering Coating on Difficult to Plate Metals
EXAMPLE 29
Five 4 inch×5 inch 304 stainless steel sheets were alkaline degreased, immersed in phosphoric acid solution, and electroplated with the Zn/Si/P coating from a solution described in Example 8. The adhesion of the deposited coating on the stainless steel substrate was tape tested. All showed good adhesion.
EXAMPLE 30
Five 304 stainless steel sheets (4"×5") were treated by nitric acid to passivate the surface (a common treatment to prevent adhesion of electroplated metal to the substrate). These passivated stainless steel sheets were electrodeposited with a Zn/Si/P coating from the solution described in Example 8. A thick coating of more than 25 microns was deposited. Edges of the coating were cut by a sharp razor. It was not possible to peel off the coating from the substrate.
The surfaces of another five sample sheets were further passivated by anodic current and electrolytically deposited with Zn/Si/P coating. Again no coating could be peeled from the substrate. The coated stainless steel samples were forced to bend and stretch many times. No peeling or breaking in the coating was observed.
EXAMPLE 31
Five 2 inch×3 inch 5052 aluminum coupons were alkali degreased and immersed in acid without any special treatment. They were electrodeposited with a Zn/Si/P coating from the solution described in Example 7. The coupons were tape tested and bend tested. No peeling of the coating from the aluminum substrate was observed.
It is to be understood that the examples are illustrative in nature and are not to be construed in a limiting sense. It is recognized that various modifications are possible within the scope of the invention claimed.
EXAMPLE 32
A plating solution was prepared using the concentrate of Example 8. Ten liters of the zinc concentrate was diluted with 28 liters of de-ionized water, and then 0.79 liters of the silicon concentrate was slowly stirred into the solution.
A plating barrel was loaded with type 430 stainless steel stampings. The stampings were anodicaly cleaned at 6 volts and 70° C. by immersing the barrel in the alkaline cleaning solution (Dynadet™, commercially available from Oakite Products Inc., Berkley Heights, NJ).
After the alkaline cleaner the barrel was immersed in first a hot water rinse at 60° C. and then a cold water rinse. The barrel with the load of stainless steel stampings was immersed in a solution of 1 part 85% phosphoric acid and 9 parts water. After rinsing in cold water, the barrel was immersed in the plating bath and the stainless steel stampings were electroplates to have a plating of approximately 75 micrometers of zinc/silicon/phosphorus coating at a current density of approximately 2.5 amperes/sq. decimeter.
The zinc/silicon/phoshorus coating, after rinsing and drying, had surprisingly excellent adhesion to the stainless steel. The plated stainless steel stampings were painted with a coating supplied by PPG Industries, Inc., Pittsburgh, PA. The adhesion of the coating over the stainless steel was excellent. There was no blistering or degradtion of the adhesion of the coating or the zinc plating during humidity testing. | The present invention provides an aqueous composition and process for the electrodeposition of a layer of zinc containing silicon and phosphorus on a metal substrate. The electrodeposition composition is prepared by reacting metallic silicon and zinc with phosphoric acid and an alkali metal hydroxide in the ratio of between 0.4 and 1.3 moles of alkali metal hydroxide per mole of phosphoric acid, and adjusting the solution to a pH of 2 or higher after completion of the reaction. The coating is deposited on the metal substrate by electrodeposition and comprises about 70% to about 99.5% by weight of zinc, and about 0.10% to about 10% by weight of silicon, and about 0.5% to about 20% by weight of phosphorus.
The resultant zinc/silicon/phosphorus coating improves the resistance of the metal substrate to corrosion, wear, galling and stress corrosion cracking. While essentially all metals of industrial importance may be coated, this process is especially important for ferrous metals, steels, stainless steels, copper, aluminum and titanium. The coated metal substrates are useful in various industries, including appliance, automobile, oil field equipment, nuclear reactor equipment, aerospace equipment, etc. | 2 |
REFERENCE TO RELATED APPLICATIONS
This application claims the priority of United Kingdom Application No. 1004812.2 filed Mar. 23, 2010, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to an accessory for a fan. Particularly, but not exclusively, the present invention relates to an accessory for a floor or table-top fan, such as a desk, tower or pedestal fan.
BACKGROUND OF THE INVENTION
A conventional domestic fan typically includes a set of blades or vanes mounted for rotation about an axis, and drive apparatus for rotating the set of blades to generate an air flow. The movement and circulation of the air flow creates a ‘wind chill’ or breeze and, as a result, the user experiences a cooling effect as heat is dissipated through convection and evaporation. The blades are generally located within a cage which allows an air flow to pass through the housing while preventing users from coming into contact with the rotating blades during use of the fan.
The use of fans in hospitals to keep patients cool is widespread, both in general wards and in isolation wards. For example, depending on the medical condition of the patient it may be preferable to reduce the body temperature of the patient using a fan rather than by using pharmaceuticals. When a fan is assigned to a patient, generally that fan is treated as an item of medical equipment and so, like other medical equipment, will require frequent cleaning by a nurse or other hospital employee. The cleaning of bladed fans can be time consuming for the employee, as the cage housing the blades of the fan needs to be disassembled before the blades of the fan can be cleaned. This disassembly usually requires the use of a screw driver, which cannot be carried by a nurse on a hospital ward. Often, it can be more convenient for the hospital to engage a specialist cleaning company to clean the fan off site, although this can be very expensive.
WO 2009/030879 describes a fan assembly which does not use caged blades to project air from the fan assembly. Instead, the fan assembly comprises a base which houses a motor-driven impeller for drawing a primary air flow into the base, and an annular nozzle connected to the base and comprising an annular slot through which the primary air flow is emitted from the fan. The nozzle defines a central opening through which air in the local environment of the fan assembly is drawn by the primary air flow emitted from the mouth, amplifying the primary air flow.
The time required to clean off the external surfaces of this type of “bladeless” fan is much shorter than that required to clean a fan having caged blades, as there is no requirement to dismantle any parts of the fan to access any exposed parts of the fan. For example, the external surfaces of the fan may be wiped clean using a cloth. While this level of cleaning may be sufficient for bladeless fans which are assigned to patients on general wards, when the bladeless fan is assigned to a patient in an isolation ward or infection containment ward there remains a need to keep the internal components of the base clean to avoid cross-contamination when the fan is assigned to another patient.
SUMMARY OF THE INVENTION
In a first aspect the present invention provides an external accessory for a portable fan comprising a base having an air inlet located in a side wall of the base, and an air outlet detachably connectable to the base, the accessory comprising a high energy particle arrester filter and attachment means for detachably connecting the accessory to the fan so that the filter is located upstream from the air inlet of the fan.
The accessory is preferably in the form of a disposable filter unit which can be replaced when, for example, the fan is assigned to a different patient, when the fan is moved with the patient from an isolation ward to a general ward, or when the filter has reached the end of a prescribed usage period. This can significantly reduce the costs associated with the use of the fan, as the frequency with which the fan may need to be taken off site for cleaning can be significantly reduced.
The accessory is particular suitable for use with a portable bladeless fan, such as the Dyson Air Multiplier™ fan, in which the fan comprises a base having an air inlet located in a side wall of the base, and an air outlet detachably connectable to the base. In this case, the accessory may be locatable over or around the base so that the filter is located upstream from the air inlet of the base to remove airborne particulates from the air flow generated by the fan before the air flow enters the base. However, the accessory can be used with any fan which generates an air flow of sufficient pressure that the air flow is not choked by the attachment of the accessory to the fan. For example, the accessory may be used with a fan which is arranged to generate an air flow with a static pressure of at least 150 Pa so that the air flow is not choked when the accessory is attached to the fan, and so in a second aspect the present invention provides an accessory for a fan for generating an air flow with a static pressure of at least 150 Pa, the accessory comprising a high energy particle arrester filter and attachment means for detachably attaching the accessory to the fan.
The attachment means are preferably manually operable to allow a user to attach the accessory to the fan, and subsequently detach the accessory from the fan, without the need for a tool.
In addition to a high energy particle arrester (HEPA) filter, the accessory may comprise one or more of a foam, carbon, paper, or fabric filter.
The accessory preferably comprises at least one seal for engaging an outer surface of the fan. This can enable the accessory to form one or more air-tight seals with the fan to ensure that the air flow generated by the fan passes through the filter and not around the filter.
In a preferred embodiment the accessory is in the form of a sleeve which is locatable about the side wall of the base of the fan. Forming the accessory in the form of a sleeve can enable the accessory to be easily pushed or pulled over the fan as required.
The filter preferably has a surface area in the range from 0.5 to 1.5 m 2 which is exposed to the air flow generated by the fan. To minimize the volume of the filter, the filter is preferably pleated to form a filter which is substantially annular in shape for surrounding an air inlet of the fan. In this case, the accessory may comprise two annular discs between which the filter is located. These discs can be easily wiped clean during use of the accessory. Each disc may comprise a raised rim extending towards the other disc for retaining the filter between the discs. The filter may be readily adhered to the discs during the construction of the accessory. The discs may together be considered to form at least part of a filter unit to which the filter is adhered during construction of the filter unit.
The accessory may comprise an outer cover comprising a plurality of apertures through which air enters the accessory. This outer cover can provide a first, relatively coarse filter of the accessory to prevent airborne objects such as insects or large particles of dust from coming into contact with the filter, and can prevent the filter from being contacted by a user, particularly during the attachment of the filter to the fan, and so prevent damage to the filter. The outer cover is preferably transparent to allow a user to see the amount of dust or debris which has been captured by the filter.
In a third aspect the present invention provides a combination of an accessory as aforementioned and a portable fan. The fan is preferably arranged to generate an air flow having a static pressure of at least 150 Pa, more preferably in the range from 250 to 1.5 kPa.
Preferably, the fan comprises an air inlet for admitting air into the fan and an air outlet for exhausting air from the fan, with the accessory being attachable to the fan so that the filter is located upstream from the air inlet of the fan. Preferably, the accessory is attachable to the fan so that the filter is located over the air inlet of the fan.
The fan may comprise a base to which the accessory is attachable, the base comprising the air inlet over which the filter is locatable. The air inlet may extend at least partially about the base, and may comprise an array of apertures. The base may be substantially cylindrical in shape. The base of the fan may house means for generating an air flow from the air inlet to the air outlet. The means for generating the air flow preferably comprises an impeller driven by a motor. A diffuser is preferably located downstream from the impeller.
The accessory may be attachable to the portable fan between the base and the air outlet of the fan so that the filter is located upstream of the air inlet of the base.
Part of the accessory may be surrounded by part of the air outlet when the accessory is attached to the fan. For example, the air outlet may comprise a base which is located over part of the accessory when the air outlet is connected to the accessory.
The accessory may comprise a first seal for engaging the base of the fan, and a second seal for engaging the air outlet of the fan so that an air flow is drawn through the filter unit between the seals and through the filter.
The attachment means may comprise means for connecting the accessory to the base, and means for connecting the accessory to the air outlet. The air outlet of the fan is preferably detachably connected to the base of the fan. The air outlet of the fan preferably comprises means for connecting the air outlet to the base, which is preferably substantially the same as the means for connecting the accessory to the base. Similarly, the base of the fan preferably comprises means for connecting the base to the air outlet, which is preferably substantially the same as the means for connecting the accessory to the air outlet. This can simplify the attachment of the accessory to the fan, as the technique for connecting the air outlet to the base is the same as that for connecting the accessory to the base, and for connecting the air outlet to the accessory.
The air outlet may comprise an interior passage for receiving an air flow and a mouth for emitting the air flow. The interior passage may extend about an opening through which air is drawn by the air flow emitted from the mouth.
In a fourth aspect the present invention provides a portable fan comprising a casing having an air inlet, a filter unit connected to the casing, the filter unit comprising a filter located upstream from the air inlet, and an air outlet connected to the filter unit.
As mentioned above, the filter unit preferably comprises means for connecting the filter unit to the base, and means for connecting the filter unit to the air outlet. The air outlet preferably comprises means for connecting the air outlet to the base, and the means for connecting the filter unit to the base is preferably substantially the same as the means for connecting the air outlet to the base. The base preferably comprises means for connecting the base to the air outlet, and the means for connecting the filter unit to the air outlet is preferably substantially the same as the means for connecting the base to the air outlet.
Features described above in connection with the first aspect of the present invention are equally applicable to any of the second to fourth aspects of the invention, and vice versa.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred features of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
FIG. 1 is a front view of a fan;
FIG. 2 is a perspective view of the base of the fan of FIG. 1 ;
FIG. 3 is a perspective view of the air outlet of the fan of FIG. 1 ;
FIG. 4 is a lower perspective view of a portion of the air outlet of the fan of FIG. 1 ;
FIG. 5 is a sectional view of the fan of FIG. 1 ;
FIG. 6 is an enlarged view of part of FIG. 5 ;
FIG. 7 is a side view of an accessory for attachment to the fan of FIG. 1 ;
FIG. 8 is a perspective view, from above, of the accessory of FIG. 7 ;
FIG. 9 is a sectional view of the accessory of FIG. 7 ;
FIG. 10 is a perspective view of the fan of FIG. 1 with the accessory of FIG. 7 attached thereto; and
FIG. 11 is a sectional view of the fan of FIG. 10 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a front view of a fan 10 . The fan 10 is preferably in the form of a bladeless fan 10 comprising a base 12 and an air outlet 14 connected to the base 12 . With reference also to FIG. 2 , the base 12 comprises a substantially cylindrical outer casing 16 having a plurality of air inlets 18 in the form of apertures formed in the outer casing 16 and through which a primary air flow is drawn into the base 12 from the external environment. The base 12 further comprises a plurality of user-operable buttons 20 and a user-operable dial 22 for controlling the operation of the fan 10 . In this example the base 12 has a height in the range from 200 to 300 mm, and the outer casing 16 has an external diameter in the range from 100 to 200 mm.
As shown in FIG. 3 , the air outlet 14 has an annular shape and defines an opening 24 . The air outlet 14 has a height in the range from 200 to 400 mm. The air outlet 14 comprises a mouth 26 located towards the rear of the fan 10 for emitting air from the fan 10 and through the opening 24 . The mouth 26 extends at least partially about the opening 24 , and preferably surrounds the opening 24 . The inner periphery of the air outlet 14 comprises a Coanda surface 28 located adjacent the mouth 26 and over which the mouth 26 directs the air emitted from the fan 10 , a diffuser surface 30 located downstream of the Coanda surface 28 and a guide surface 32 located downstream of the diffuser surface 30 . The diffuser surface 30 is arranged to taper away from the central axis X of the opening 24 in such a way so as to assist the flow of air emitted from the fan 10 . The angle subtended between the diffuser surface 30 and the central axis X of the opening 24 is in the range from 5 to 25°, and in this example is around 15°. The guide surface 32 is arranged at an angle to the diffuser surface 30 to further assist the efficient delivery of a cooling air flow from the fan 10 . The guide surface 32 is preferably arranged substantially parallel to the central axis X of the opening 24 to present a substantially flat and substantially smooth face to the air flow emitted from the mouth 26 . A visually appealing tapered surface 34 is located downstream from the guide surface 32 , terminating at a tip surface 36 lying substantially perpendicular to the central axis X of the opening 24 . The angle subtended between the tapered surface 34 and the central axis X of the opening 24 is preferably around 45°. The overall depth of the air outlet 14 in a direction extending along the central axis X of the opening 24 is in the range from 100 to 150 mm, and in this example is around 110 mm.
FIG. 5 illustrates a sectional view through the fan 10 . The base 12 comprises a lower base member 38 , an intermediary base member 40 mounted on the lower base member 38 , and an upper base member 42 mounted on the intermediary base member 40 . The lower base member 38 has a substantially flat bottom surface 43 . The intermediary base member 40 houses a controller 44 for controlling the operation of the fan 10 in response to depression of the user operable buttons 20 shown in FIGS. 1 and 2 , and/or manipulation of the user operable dial 22 . The intermediary base member 40 may also house an oscillating mechanism 46 for oscillating the intermediary base member 40 and the upper base member 42 relative to the lower base member 38 . The range of each oscillation cycle of the upper base member 42 is preferably between 60° and 120°, and in this example is around 90°. In this example, the oscillating mechanism 46 is arranged to perform around 3 to 5 oscillation cycles per minute. A mains power cable 48 extends through an aperture formed in the lower base member 38 for supplying electrical power to the fan 10 .
The upper base member 42 may be tilted relative to the intermediary base member 40 to adjust the direction in which the primary air flow is emitted from the fan 10 . For example, the upper surface of the intermediary base member 40 and the lower surface of the upper base member 42 may be provided with interconnecting features which allow the upper base member 42 to move relative to the intermediary base member 40 while preventing the upper base member 42 from being lifted from the intermediary base member 40 . For example, the intermediary base member 40 and the upper base member 42 may comprise interlocking L-shaped members.
The upper base member 42 has an open upper end, and comprises an array of apertures 50 which extend at least partially about the upper base member 42 . The apertures 50 provide the air inlet 18 of the base 12 . The upper base member 42 houses an impeller 52 for drawing the primary air flow through the apertures 50 and into the base 12 . Preferably, the impeller 52 is in the form of a mixed flow impeller. The impeller 52 is connected to a rotary shaft 54 extending outwardly from a motor 56 . In this example, the motor 56 is a DC brushless motor having a speed which is variable by the controller 44 in response to user manipulation of the dial 22 . The maximum speed of the motor 56 is preferably in the range from 5,000 to 10,000 rpm. The motor 56 is housed within a motor bucket comprising an upper portion 58 connected to a lower portion 60 . The motor bucket is retained within the upper base member 42 by a motor bucket retainer 62 . The upper end of the upper base member 42 comprises a cylindrical outer surface 64 . The motor bucket retainer 62 is connected to the open upper end of the upper base member 42 , for example by a snap-fit connection. The motor 56 and its motor bucket are not rigidly connected to the motor bucket retainer 62 , allowing some movement of the motor 56 within the upper base member 42 .
Returning to FIG. 2 , the upper end of the upper base member 42 comprises two pairs of open grooves 66 formed by removing part of the outer surface 64 to leave a shaped ‘cutaway’ portion. The upper end of each of the grooves 66 is in open communication with the open upper end of the upper base member 42 . The open groove 66 is arranged to extend downwardly from the open upper end of the upper base member 42 . A lower part of the groove 66 comprises a circumferentially extending track 68 having upper and lower portions bounded by the outer surface 64 of the upper base member 42 . Each pair of open grooves 66 is located symmetrically about the upper end of the upper base member 42 , the pairs being spaced circumferentially from each other. An annular sealing member 69 extends about the outer surface of the upper base member 42 , and is located beneath the tracks 68 of the grooves 66 .
The cylindrical outer surface 64 of the upper end of the upper base member 42 further comprises a pair of wedge members 70 having a tapered part 72 and a side wall 74 . The wedge members 70 are located on opposite sides of the upper base member 42 , with each wedge member 70 being located within a respective cutaway portion of the outer surface 64 .
The motor bucket retainer 62 comprises curved vane portions 76 , 78 extending inwardly from the upper end of the motor bucket retainer 62 . Each curved vane 76 , 78 overlaps a part of the upper portion 58 of the motor bucket. Thus the motor bucket retainer 62 and the curved vanes 76 , 78 act to secure and hold the motor bucket in place during movement and handling. In particular, the motor bucket retainer 62 prevents the motor bucket from becoming dislodged and falling towards the air outlet 14 if the fan 10 becomes inverted.
With reference again to FIG. 5 , one of the upper portion 58 and the lower portion 60 of the motor bucket comprises a diffuser 80 in the form of a stationary disc having spiral fins 82 , and which is located downstream from the impeller 52 . One of the spiral fins 82 has a substantially inverted U-shaped cross-section when sectioned along a line passing vertically through the upper base member 42 . This spiral fin 82 is shaped to enable a power connection cable to pass through the spiral fin 82 to the motor 56 .
The motor bucket is located within, and mounted on, an impeller housing 84 . The impeller housing 84 is, in turn, mounted on a plurality of angularly spaced supports 86 , in this example three supports, located within the upper base member 42 of the base 12 . A generally frusto-conical shroud 88 is located within the impeller housing 84 . The shroud 88 is preferably connected to the outer edges of the impeller 52 , and is shaped so that the outer surface of the shroud 88 is in close proximity to, but does not contact, the inner surface of the impeller housing 84 . A substantially annular inlet member 90 is connected to the bottom of the impeller housing 84 for guiding the primary air flow into the impeller housing 84 . The top of the impeller housing 84 comprises a substantially annular air outlet 92 for guiding air flow emitted from the impeller housing 84 towards the air outlet 14 .
Preferably, the base 12 further comprises silencing members for reducing noise emissions from the base 12 . In this example, the upper base member 42 of the base 12 comprises a disc-shaped foam member 94 located towards the base of the upper base member 42 , and a substantially annular foam member 96 located within the impeller housing 84 .
A flexible sealing member is mounted on the impeller housing 84 . The flexible sealing member inhibits the return of air to the air inlet member 90 along a path extending between the outer casing 16 and the impeller housing 84 by separating the primary air flow drawn in from the external environment from the air flow emitted from the air outlet 92 of the impeller 52 and the diffuser 80 . The sealing member preferably comprises a lip seal 98 . The sealing member is annular in shape and surrounds the impeller housing 84 , extending outwardly from the impeller housing 84 towards the outer casing 16 . In the illustrated embodiment the diameter of the sealing member is greater than the radial distance from the impeller housing 84 to the outer casing 16 . Thus the outer portion 100 of the sealing member is biased against the outer casing 16 and caused to extend along the inner face of the outer casing 16 , forming a seal. The lip seal 98 of the preferred embodiment tapers and narrows to a tip 102 as it extends away from the impeller housing 84 and towards the outer casing 16 . The lip seal 98 is preferably formed from rubber.
The sealing member further comprises a guide portion 104 for guiding a power connection cable 106 to the motor 56 . The guide portion 104 of the illustrated embodiment is formed in the shape of a collar and may be a grommet. The electrical cable 106 is in the form of a ribbon cable attached to the motor at joint 108 . The electrical cable 106 extending from the motor 56 passes out of the lower portion 60 of the motor bucket through spiral fin 82 . The passage of the electrical cable 106 follows the shaping of the impeller housing 84 and the guide portion 104 is shaped to enable the electrical cable 106 to pass through the flexible sealing member. The guide portion 104 of the sealing member enables the electrical cable 106 to be clamped and held within the upper base member 42 . A cuff 110 accommodates the electrical cable 106 within the lower portion of the upper base member 42 .
FIG. 6 illustrates a sectional view through the air outlet 14 . The air outlet 14 comprises an annular outer casing section 120 connected to and extending about an annular inner casing section 122 . Each of these sections may be formed from a plurality of connected parts, but in this embodiment each of the outer casing section 120 and the inner casing section 122 is formed from a respective, single molded part. The inner casing section 122 defines the central opening 24 of the air outlet 14 , and has an external peripheral surface 124 which is shaped to define the Coanda surface 28 , diffuser surface 30 , guide surface 32 and tapered surface 34 .
The outer casing section 120 and the inner casing section 122 together define an annular interior passage 126 of the air outlet 14 . Thus, the interior passage 126 extends about the opening 24 . The interior passage 126 is bounded by the internal peripheral surface 128 of the outer casing section 120 and the internal peripheral surface 130 of the inner casing section 122 . As shown in FIG. 4 , the outer casing section 120 comprises a base 132 having an inner surface 134 . Formed on the inner surface 134 of the base 132 are two pairs of lugs 136 and a pair of ramps 138 for connection to the upper end of the upper base member 42 . Each lug 136 and each ramp 138 upstands from the inner surface 134 . Thus the base 132 is connected to, and over, the open upper end of the motor bucket retainer 62 and the upper base member 42 of the base 12 . The pairs of lugs 136 are located around the outer casing section 120 and spaced from each other so that the pairs of lugs 136 correspond to the spaced arrangement of the pairs of open grooves 66 of the upper end of the upper base member 42 and so that the location of the pair of ramps 138 corresponds to the location of the pair of wedge members 70 of the upper end of the upper base member 42 .
The base 132 of the outer casing section 120 comprises an aperture through which the primary air flow enters the interior passage 126 of the air outlet 14 from the upper end of the upper base member 42 and the open upper end of the motor bucket retainer 62 .
The mouth 26 of the air outlet 14 is located towards the rear of the fan 10 . The mouth 26 is defined by overlapping, or facing, portions 140 , 142 of the internal peripheral surface 128 of the outer casing section 120 and the external peripheral surface 124 of the inner casing section 122 , respectively. In this example, the mouth 26 is substantially annular and, as illustrated in FIG. 4 , has a substantially U-shaped cross-section when sectioned along a line passing diametrically through the air outlet 14 . In this example, the overlapping portions 140 , 142 of the internal peripheral surface 128 of the outer casing section 120 and the external peripheral surface 124 of the inner casing section 122 are shaped so that the mouth 26 tapers towards an outlet 144 arranged to direct the primary flow over the Coanda surface 28 . The outlet 144 is in the form of an annular slot, preferably having a relatively constant width in the range from 0.5 to 5 mm. In this example the outlet 144 has a width of around 1 mm. Spacers may be spaced about the mouth 26 for urging apart the overlapping portions 140 , 142 of the internal peripheral surface 128 of the outer casing section 120 and the external peripheral surface 124 of the inner casing section 122 to maintain the width of the outlet 144 at the desired level. These spacers may be integral with either the internal peripheral surface 128 of the outer casing section 120 or the external peripheral surface 124 of the inner casing section 122 .
Referring to FIGS. 3 and 4 , to attach the air outlet 14 to the base 12 , the air outlet 14 is inverted from the orientation illustrated in FIG. 4 and the base 132 of the air outlet 14 is located over the open upper end of the upper base member 42 . The air outlet 14 is aligned relative to the base 12 so that the lugs 136 of the base 132 of the air outlet 14 are located directly in line with the open upper ends of the open grooves 66 of the upper base member 42 . In this position the pair of ramps 138 of the base 132 is directly in line with the pair of wedge members 70 of the upper base member 42 . The air outlet 14 is then pushed on to the base 12 so that the lugs 136 are located at the base of the open grooves 66 . The sealing member 69 of the base 12 engages the inner surface 134 of the base 132 of the air outlet 14 to form an air-tight seal between the base 12 and the air outlet 14 .
To secure the air outlet 14 to the base 12 , the air outlet 14 is rotated in a clockwise direction relative to the base 12 so that the lugs 136 move along the circumferentially extending tracks 68 of the open grooves 66 . The rotation of the air outlet 14 relative to the base 12 also forces the ramps 138 to run up and slide over the tapers 72 of the wedge member 70 through localized elastic deformation of the open upper end of the upper base member 42 . With continued rotation of the air outlet 14 relative to the base 12 , the ramps 138 are forced over the side walls 74 of the wedge members 70 . The open upper end of the upper base member 42 relaxes so that the ramps 138 are generally radially aligned with the wedge members 70 . Consequently, the side walls 74 of the wedge members 70 prevent accidental rotation of the air outlet 14 relative to the base 12 , whereas the location the lugs 136 within the tracks 68 prevents lifting of the air outlet 14 away from the base 12 . The rotation of the air outlet 14 relative to the base 12 does not require excessive rotational force and so the assembly of the fan 10 may be carried out by a user.
To operate the fan 10 the user depresses an appropriate one of the buttons 20 on the base 12 , in response to which the controller 44 activates the motor 56 to rotate the impeller 52 . The rotation of the impeller 52 causes a primary air flow to be drawn into the base 12 through the air inlet 18 . Depending on the speed of the motor 56 , the primary air flow generated by the impeller 52 may be between 20 and 30 liters per second. The pressure of the primary air flow at the outlet 92 of the base 12 may be at least 150 Pa, and is preferably in the range from 250 to 1.5 kPa. The primary air flow passes sequentially through the impeller housing 84 , the upper end of the upper base member 42 and open upper end of the motor bucket retainer 62 to enter the interior passage 126 of the air outlet 14 . The primary air flow emitted from the air outlet 92 of the base 12 is generally in an upward and forward direction.
Within the air outlet 14 , the primary air flow is divided into two air streams which pass in opposite directions around the central opening 24 of the air outlet 14 . Part of the primary air flow entering the air outlet 14 in a sideways direction (generally orthogonal to the axis X) passes into the interior passage 126 in a sideways direction without significant guidance, whereas another part of the primary air flow entering the air outlet 14 in a direction parallel to the axis X is guided by the curved vanes 76 , 78 of the motor bucket retainer 62 to enable the air flow to pass into the interior passage 126 in a sideways direction. As the air streams pass through the interior passage 126 , air enters the mouth 26 of the air outlet 14 . The air flow into the mouth 26 is preferably substantially even about the opening 24 of the air outlet 14 . Within each section of the mouth 26 , the flow direction of the portion of the air stream is substantially reversed. The portion of the air stream is constricted by the tapering section of the mouth 26 and emitted through the outlet 98 .
The primary air flow emitted from the mouth 26 is directed over the Coanda surface 28 of the air outlet 14 , causing a secondary air flow to be generated by the entrainment of air from the external environment, specifically from the region around the outlet 98 of the mouth 26 and from around the rear of the air outlet 14 . This secondary air flow passes through the central opening 24 of the air outlet 14 , where it combines with the primary air flow to produce a total air flow, or air current, projected forward from the air outlet 14 . Depending on the speed of the motor 56 , the mass flow rate of the air current projected forward from the fan 10 may be in the range from 300 to 400 liters per second, and the maximum speed of the air current may be in the range from 2.5 to 4 m/s.
The even distribution of the primary air flow along the mouth 26 of the air outlet 14 ensures that the air flow passes evenly over the diffuser surface 30 . The diffuser surface 30 causes the mean speed of the air flow to be reduced by moving the air flow through a region of controlled expansion. The relatively shallow angle of the diffuser surface 30 to the axis X of the opening 24 allows the expansion of the air flow to occur gradually. A harsh or rapid divergence would otherwise cause the air flow to become disrupted, generating vortices in the expansion region. Such vortices can lead to an increase in turbulence and associated noise in the air flow which can be undesirable, particularly in a domestic product such as a fan. The air flow projected forwards beyond the diffuser surface 30 can tend to continue to diverge. The guide surface 32 extending inwardly towards the axis X converges the air flow towards the axis X. As a result, the air flow can travel efficiently out from the air outlet 14 , enabling rapid air flow to be experienced at a distance of several meters from the fan 10 .
FIGS. 7 to 9 illustrate an external accessory for the fan 10 . The accessory is in the form of a filter unit 200 which is detachably attachable to the fan 10 to allow the filter unit 200 to be removed for cleaning or replacement.
The filter unit 200 is in the form of a generally cylindrical sleeve which is locatable around the upper base member 42 of the base 12 so that the filter unit 200 is located over the air inlet 18 of the fan 10 , as illustrated in FIGS. 10 and 11 . This allows the filter unit 200 to remove airborne particles from the primary air flow generated by the fan 10 before the primary air flow enters the base 12 of the fan 10 .
The filter unit 200 comprises a generally annular filter 202 for removing airborne particles from the primary air flow. The filter 202 is preferably in the form of a radially pleated high energy particle arrester (HEPA) filter. The filter 202 has a surface area that is exposed to the incoming primary air flow generated by the fan which is in the range from 0.5 to 1.5 m 2 , and in this example is around 1.1 m 2 . The filter 202 is surrounded by a cylindrical outer cover 204 , which is preferably formed from plastics material, to protect the filter 202 and thus allows a user to handle the filter unit 200 without contacting the filter 202 . The cover 204 is preferably transparent to allow a user to examine visually the state of the filter 202 during use or after a period of use. The cover 204 comprises a plurality of apertures (not shown) through which the primary air flow enters the filter unit 200 , and thus provides a relatively coarse first stage of filtration of the filter unit 200 to prevent relatively large airborne objects or insects from entering the filter unit 200 . The filter unit 200 may further comprise additional filter media between the filter 202 and the cover 204 , or downstream from the filter 202 . For example, this additional filter media may comprise one or more of foam, carbon, paper, or fabric.
The filter 202 and the cover 204 are sandwiched between two annular plates 206 , 208 of the filter unit 200 . Each plate 206 , 208 includes a circular inner rim 210 and a circular outer rim 212 which both extend partially towards the other plate 206 , 208 . The filter 202 and the cover 204 are located between the rims 210 , 212 of the plates 206 , 208 , and are preferably secured to the plates 206 , 208 using an adhesive.
The upper plate 206 comprises a lower collar 214 which is located radially inwardly from the inner rim 210 of the upper plate 206 . The lower collar 214 extends axially downwards from the upper plate 206 . The inner diameter of the lower collar 214 is substantially the same as the inner diameter of the base 132 of the air outlet 14 of the fan 10 . Similar to the base 132 of the air outlet 14 , the inner surface of the lower collar 214 comprises two pairs of lugs 216 and a pair of ramps (not shown) for connection to the upper end of the upper base member 42 of the base 12 of the fan 10 . The shape of the lugs 216 and the ramps of the lower collar 214 , and the angular spacing between the lugs 216 and the ramps of the lower collar 214 , are substantially identical to those of the lugs 136 and ramps 138 of the base 132 of the air outlet 14 .
The upper plate 206 further comprises an upper collar 218 which is located radially inwardly from the lower collar 214 . The upper collar 218 extends axially upwards from the inner circumferential periphery of the upper plate 208 . The outer diameter of the upper collar 218 is substantially the same as the outer diameter of the outer surface 64 of the open upper end of the upper base member 42 . Similar to the upper base member 42 , the upper collar 218 comprises two pairs of open grooves 220 and a pair of wedge members 222 . The open grooves 220 are substantially identical to the open grooves 66 of the outer surface 64 of the upper base member 42 , and the spacing between the open grooves 220 is substantially the same as that between the open grooves 66 . The wedge members 222 are substantially identical to the wedge members 70 of the outer surface 64 of the upper base member 42 , and the spacing between the wedge members 222 is substantially the same as that between the wedge members 70 . A first annular sealing member 224 of the filter unit 200 extends about the outer surface of the upper collar 218 , and is located beneath the circumferentially extending tracks 226 of the grooves 220 .
The collars 214 , 218 are preferably integral with the upper plate 206 , which is preferably formed from plastics material.
The lower plate 208 includes a relatively small collar 228 which extends axially downwardly from the inner rim 210 of the lower plate 208 . The collar 228 comprises a circumferentially extending groove located on its inner surface. A second annular sealing member 230 of the filter unit 200 is located within this groove. The collar 228 is preferably integral with the lower plate 208 , which is also preferably formed from a plastics material.
To attach the filter unit 200 to the fan 10 , first the air outlet 14 is detached from the base 12 . To detach the air outlet 14 from the base 12 , the air outlet 14 is twisted relative to the base 12 in the opposite direction (anti-clockwise) to that for attaching the air outlet 14 to the base 12 . With a suitable torque applied manually by the user, the upper end of the upper base member 42 is again caused to flex locally radially inwardly. This localized deformation of the upper base member 42 allows the ramp 138 to be rotated over the wedge members 70 , while the lugs 136 are moved simultaneously along the tracks 68 of the grooves 66 . Once the lugs 136 reach the ends of the tracks 68 , the air outlet 14 may be lifted from the base 12 .
Although the detachment of the air outlet 14 from the base 12 requires a greater force to be applied to the air outlet 14 than the force required for attachment, the resilience of the upper base member 42 is selected so that the detachment of the air outlet 14 may be performed manually
The user then attaches the filter unit 200 to the base 12 . The technique for attaching the filter unit 200 to the base 12 is essentially the same as that for attaching the air outlet 14 to the base 12 . The user locates the open lower end of the collar 228 of the lower plate 208 over the open upper end of the upper base member 42 , and lowers the filter unit 200 around the base 12 . When the bottom end of the lower collar 214 of the upper plate 206 is located immediately above the open upper end of the upper base member 42 , the user rotates the filter unit 200 until the lugs 216 of the filter unit 200 are located directly in line with the open upper end of the open grooves 66 of the upper base member 42 . In this position the pair of ramps of the filter unit is directly in line with the pair of wedge members 70 of the upper base member 42 . The filter unit 200 is then pushed further on to the base 12 so that the lugs 216 of the filter unit 200 are located at the base of the open grooves 66 of the base 12 . To secure the filter unit 200 to the base 12 , the filter unit 200 is rotated in a clockwise direction relative to the base 12 so that the lugs 216 move along the circumferentially extending tracks 68 of the open grooves 66 . The rotation of the filter unit 200 relative to the base 12 also forces the ramps to run up and slide over the tapers 72 of the wedge members 70 through localized elastic deformation of the upper base member 42 . With continued rotation of the filter unit 200 relative to the base 12 , the ramps are forced over the side walls 74 of the wedge members 70 . The upper base member 42 relaxes so that the ramps are generally radially aligned with the wedge members 70 . Consequently, the side walls 74 of the wedge members 70 prevent accidental rotation of the filter unit 200 relative to the base 12 , whereas the location the lugs 216 within the tracks 68 prevents lifting of the filter unit 200 away from the base 12 .
As shown in FIG. 11 , when the filter unit 200 is attached to the base 12 the second sealing member 230 of the filter unit 200 is located beneath the air inlet 18 of the base 12 , and engages the outer surface of the base 12 to form an air-tight seal between the base 12 and the filter unit 200 . As also shown in FIG. 10 , the buttons 22 and user operable dial 22 of the base 12 remain accessible by the user when the filter unit 200 is attached to the base 12 .
The air outlet 14 is then attached to the filter unit 200 . The attachment of the air outlet 14 to the filter unit 200 is essentially the same as the attachment of the air outlet 14 to the base 12 . The base 132 of the air outlet 14 is located over the upper collar 218 of the filter unit 200 , and the air outlet 14 is aligned relative to the base 12 so that the lugs 136 of the base 132 of the air outlet 14 are located directly in line with the open upper end of the open grooves 220 of the filter unit 200 . The air outlet 14 is then pushed on to the filter unit 200 so that the lugs 136 are located at the base of the open grooves 220 . The first sealing member 224 of the filter unit 200 engages the inner surface 134 of the base 132 of the air outlet 14 to form an air-tight seal between the filter unit 200 and the air outlet 14 . Again, to secure the air outlet 14 to the filter unit 200 the air outlet 14 is rotated in a clockwise direction relative to the filter unit 200 so that the lugs 136 move along the circumferentially extending tracks 226 of the open grooves 220 of the filter unit 200 . The rotation of the air outlet 14 relative to the filter unit 200 also forces the ramps 138 to run up and slide over the tapers of the wedge members 222 of the filter unit 200 through localized elastic deformation of the upper collar 218 . With continued rotation of the air outlet 14 relative to the filter unit 200 , the ramps 138 are forced over the side walls of the wedge members 220 . The upper collar 218 relaxes so that the ramps 138 are generally radially aligned with the wedge members 220 . Consequently, the side walls of the wedge members 200 prevent accidental rotation of the air outlet 14 relative to the filter unit 200 , whereas the location the lugs 136 within the tracks 226 of the grooves 200 prevents lifting of the air outlet 14 away from the filter unit 200 .
The assembled combination of the fan 10 and the filter unit 200 is shown in FIGS. 10 and 11 . The air-tight seals that the filter unit 200 makes with the base 12 and the air outlet 14 force the primary air flow to pass through the filter 202 of the filter unit 200 to remove airborne particulates from the primary air flow before it enters the base 12 . In addition to purifying the air in the local environment of the fan 10 , the removal of airborne particulates from the primary air flow before it enters the base 12 can significantly reduce the rate at which dust and debris can build-up on the internal components of the fan 10 , thereby reducing the frequency at which the fan 10 needs to be cleaned. The filter unit 200 may be easily replaced for cleaning or replacement by detaching the air outlet 14 from the filter unit 200 , which is performed in the same manner as the removal of the air outlet 14 from the base 12 , and subsequently detaching the filter unit 200 from the base 12 . This can be performed quickly and easily without the use of any tools. When the use of the filter unit 200 is no longer required, the filter unit 200 can be rapidly removed from the fan 10 by detaching the filter unit 200 from the base 12 , and re-attaching the air outlet 14 directly to the base 12 . | An external accessory for a portable fan including a base having an air inlet located in a side wall of the base, and an air outlet detachably connectable to the base, the accessory including a high energy particle arrester filter and connectors for detachably connecting the accessory to the fan so that the filter is located upstream from the air inlet of the fan. | 5 |
BACKGROUND OF THE INVENTION
[0001] This invention relates to an electric shower-waste pump and control unit. Self-contained shower-waste pump and control units are known, and can be obtained from Autumn (UK) Limited of Ashton-under-Lyne, Lancashire, United Kingdom, Impey (UK) Limited of Ilton, Somerset, United Kingdom, and Digital Pumps Limited of Blackpool, Lancashire, United Kingdom.
[0002] Prior art examples of such units 1 are shown in FIGS. 1 to 3 . Each unit 1 comprises a water-tightly sealable housing 2 in which is housed a shower-waste pump 3 and appropriate electronic control circuitry 4 . An external mains AC electricity supply, typically of 230 or 240 volts, is connected via a connector 5 to a power transformer 6 forming part of the electronic control circuitry within the housing. The power transformer converts the mains voltage to a lower voltage suitable for operating the pump and the control circuitry.
[0003] Such a unit 1 is typically connected to a shower 7 as shown in FIG. 4 . The shower head 8 is provided above a shower tray 9 having a waste outlet 10 . The shower head is connected to a, typically wall-mounted, shower unit 11 , which in turn is connected to a mains water supply 12 .
[0004] A flow sensor 13 or sensors is/are connected to the shower-waste pump and control unit 1 and monitor operation of the shower unit. The shower-waste pump and control unit itself is connected to a mains power supply 14 .
[0005] The waste outlet of the shower tray is connected to one port 15 of the pump 3 of the shower-waste pump and control unit, and another port 16 of the pump discharges to a drain pipe 17 and then to a soil pipe 18 of the building.
[0006] The problem with such prior art arrangements is that, should the pump leak, the water-tightly sealed box can fill with water. This leads to direct contact with the electrically energised control circuitry. The water leaking from the pump thus forms a conduction path back to the floor of the shower tray or base presenting a serious and potentially fatal risk of electrocution.
[0007] The pump utilised in such units is often of a diaphragm variety, and this kind of pump is well known to fail through diaphragm wear. Leakage of water through a worn diaphragm frequently occurs. The water can thus pass out of a pump housing and into the housing of the unit by flowing through an air vent hole intentionally provided for venting air from behind the diaphragm.
[0008] This is a known problem which has not heretobefore been addressed, and the present invention seeks to provide a solution.
SUMMARY OF THE INVENTION
[0009] According to the present invention, there is provided an electric shower-waste pump and control unit for pumping run-off shower water from a waste outlet to a drain, the unit comprising a housing having a first chamber and a separate second chamber which is water-tightly sealable, a removable housing cover for closing the housing, an electric pump provided in the first chamber, electronic control circuitry provided in the second chamber, and a removable second chamber cover for water-tightly sealing the second chamber against ingress of water leakage from the pump.
[0010] The present invention will now be more particularly described, by way of example only, with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIGS. 1 to 3 show first to third prior art electric shower-waste pump and control units;
[0012] FIG. 4 shows a known standard installation of the electric shower-waste pump and control unit;
[0013] FIG. 5 shows a perspective view of a first embodiment of an electric shower-waste pump and control unit, in accordance with the invention and with a housing cover and a second chamber cover removed;
[0014] FIG. 6 is a view similar to FIG. 5 , but with a shower-waste pump removed;
[0015] FIG. 7 is a plan view of the unit shown in FIG. 5 , but with the second chamber cover in place;
[0016] FIG. 8 is a perspective view of the unit shown in FIG. 5 , but with the housing cover in place;
[0017] FIG. 9 is diagrammatic side view of a second embodiment of an electric shower-waste pump and control unit, in accordance with the invention; and
[0018] FIG. 10 is a perspective view of a third embodiment of an electric shower-waste pump and control unit, in accordance with the invention and with the front housing cover and pump removed for clarity.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Referring to FIGS. 5 to 8 , there is shown a first embodiment of an electric shower-waste pump and control unit 110 which comprises a, typically moulded plastics, housing 112 having a first pump chamber 114 and a second control-circuitry chamber 116 , a removable housing cover 118 for closing the housing 112 , and a removable second chamber cover 120 for closing the second chamber 116 .
[0020] An electric shower-waste pump 122 is provided in the first chamber 114 , and electronic control circuitry 124 is provided in the second chamber 116 . The electronic control circuitry 124 includes a power transformer 126 , and user-controls 128 for controlling and setting characteristics and/or parameters of the pump 122 , such as ramp-up and ramp-down times, delay times, and pumping rate.
[0021] The second chamber 116 is separate of the first chamber 114 , and is defined by a continuous wall 130 which is provided within the first chamber 114 . The continuous wall 130 of the second chamber 116 is typically integrally moulded as part of the housing 112 .
[0022] An opening (not shown) is typically provided in the wall of the second chamber 116 , so that the pump 122 can be electrically connected to the control circuitry 124 . A water-tight gland is provided in the opening.
[0023] The second chamber 116 also includes a second opening or openings 131 for the passage of a mains electricity supply cable (not shown). Again, the or each second opening 131 includes a water-tight gland 131 a.
[0024] The second chamber cover 120 watertightly seals the second chamber 116 to IPx4 or IPx5 according to British Standard EN 60529. A sealing gasket (not shown) can be provided on a lower surface of the second chamber cover 120 to receive the continuous wall 130 of the second chamber 116 .
[0025] Spaced-apart screw-port bosses 132 are integrally moulded within the first chamber 114 and are spaced from the continuous wall 130 of the second chamber 116 . However, the continuous wall of the second chamber can include the spaced-apart screw-port bosses.
[0026] The second chamber cover 120 is thus releasably fastened to an upper edge 134 of the continuous wall 130 , via screw-threaded fasteners 136 received in the screw-port bosses 132 , in order to water-tightly seal the second chamber 116 .
[0027] An access opening 138 is provided in the second chamber cover 120 . The access opening 138 is positioned to allow simple unhindered access to the user-controls 128 and/or connectors 140 of the control circuitry 124 for use in commissioning purposes.
[0028] In this embodiment, a removable access cover 142 water-tightly closes the access opening 138 , typically via a sealing gasket (not shown) and screw-threaded fasteners 144 , to maintain the water-tight sealing of the second chamber 116 .
[0029] Referring to FIG. 9 , a second embodiment of an electric shower-waste pump and control unit 210 is shown. This embodiment is similar to that of the first embodiment, except a second chamber cover 220 is provided in or on a rear surface of housing 212 .
[0030] Access cover 242 is spaced from the second chamber cover 220 , and is accessible from the front of the housing 212 by removal of housing cover 218 , as in the first embodiment.
[0031] As such, electronic control circuitry 224 is positioned within second chamber 216 from the rear of the housing 212 and prior to installation of the unit 210 . Once installed, typically on a wall, access to the control circuitry 224 is only possible via access opening 238 , and even then, only user-controls and/or connectors are typically accessible.
[0032] As in the first embodiment, the second chamber cover 220 and the access cover 242 water-tightly seal the second chamber 216 .
[0033] Referring to FIG. 10 , a third embodiment of an electric shower-waste pump and control unit 310 is shown. This embodiment is again similar to that of the first embodiment, and therefore like parts have like references, except with ‘ 300 ’ added. FIG. 10 only shows a base of the housing 312 in which can be seen the first pump chamber 314 , the second control-circuitry chamber 316 , and the second chamber cover 320 .
[0034] In this case, the second chamber 316 provides a bridge-shaped recess 346 for a pump motor (not shown), such that the second chamber 316 straddles the pump motor, when assembled.
[0035] The access cover 342 of this embodiment cannot be removed, and is instead a waterproof transparent or translucent flexible plastics membrane 348 which seals the access cover against the ingress of liquid. Since the membrane 348 is flexible, a user can manipulate the controls therebeneath through the membrane 348 .
[0036] As such, with a housing cover removed, but with the second chamber cover 320 in place, the user controls 328 of the control circuitry 324 are only accessible via the access opening 338 , although without requiring removal of the access cover 342 .
[0037] Although the access cover of this embodiment is provided in the second chamber cover, similar to the first embodiment, it can be provided separately of the second chamber cover, similarly to the second embodiment.
[0038] The flexible access cover may be opaque with the controls embossed or printed thereon. Alternatively, the access cover can be a waterproof touch-sensitive control panel, such as a capacitative, inductive and/or piezoelectric device.
[0039] The housing cover of the embodiments described above not only closes the housing, but also closes the first chamber. The housing cover does not water-tightly seal the housing or the first chamber, thereby allowing drainage of water within the first chamber.
[0040] Screw-threaded fasteners are suggested, and these can be formed to be engagable by hand, instead of or in addition to the use of a tool, in order to simply removal and relocation of the second chamber cover and/or the access cover.
[0041] Alternatively, a releasable snap-lock fastening device or any other suitable device can be utilised in place of the afore-mentioned screw-threaded fastener.
[0042] Sealing of the second chamber cover and/or the access cover can alternatively be achieved by a moulded-in flexible gasket material applied to a bottom surface to form a compressible self-bonding sealing element.
[0043] Although the second chamber is formed integrally as part of the housing, the second chamber can be independent of the housing and simply attached therein when required.
[0044] It is thus possible to provide of a self-contained electric shower-waste pump and control unit which liquidly-isolates electronic control circuitry from its associated electric shower-waste pump and from water ingress via a misdirected shower head. It is also possible to provide such a unit which still allows simple user access to the control-circuitry.
[0045] The embodiments described above are given by way of examples only, and various other modifications will be apparent to persons skilled in the art without departing from the scope of the invention, as defined by the appended claims. | An electric shower-waste pump and control unit for pumping run-off shower water from a waste outlet to a drain, the unit comprising a housing having a first chamber and a separate second chamber which is water-tightly sealable, a removable housing cover for closing the housing, an electric pump provided in the first chamber, electronic control circuitry provided in the second chamber, and a removable second chamber cover for water-tightly sealing the second chamber against ingress of water leakage from the pump. | 5 |
BACKGROUND OF THE INVENTION
1) Field of the Invention
The present invention relates to an actuator for a vehicle, and more specifically, to an actuator for a door locking device of a four-wheel automobile.
2) Description of the Related Art
It is a common practice to provide a door locking device between an outside handle and a latch mechanism of a door provided in the chassis of the automobile. The latch mechanism normally includes a latch and a ratchet. When the automobile door is shut against the chassis, the latch engages in a striker provided on the chassis and the ratchet maintains this locked state.
The door locking device is locked and unlocked in a switchable manner by manual operation or electronic control. The manual operation involves using a key on the externally provided key cylinder or from within the chassis by pushing a locking button provided inside. The electronic control is performed, for example, by a so-called keyless entry with a remote controller.
The door locking device allows, when being in an unlocked condition, the door to be opened with the outside handle. Concretely, the ratchet releases its hold on the latch and the striker, thus enabling the door to be opened.
On the other hand, the door locking device does not allow, when being in a locked condition, the door to be opened with the outside handle. In other words, the ratchet maintains its hold on the latch and the striker.
Such a door locking mechanism includes an actuator disclosed in, for example, Japanese Utility Model Laid-Open Publication No. H5-52150, Japanese Utility Model No. 2513398, and Japanese Utility Model No. 2529569. FIG. 8 is a plan view of a conventional actuator. The actuator 100 includes a driving motor 110 , a worm wheel 120 , and an output lever 130 .
The driving motor 110 is housed in a casing 1 and can turn both clockwise and counter-clockwise. The driving motor 110 is driven according to the electronic control, and has a driving shaft 1110 and a cylindrical worm 1120 mounted on the driving shaft 1110 . The driving shaft 1110 and the worm 1120 turn in unison.
The worm wheel 120 is disc-shaped and is housed in the casing 1 . The worm wheel 120 is rotatably supported by a supporting shaft 1210 . The worm wheel 120 is engaged with the worm 1120 at a periphery of the worm wheel 120 . Consequently, the worm wheel 120 is a rotor that turns in a normal direction or the opposite direction through the worm 1120 driven by the driving motor 110 . The worm wheel 120 is illustrated in FIG. 8 as a rotor that turns clockwise or counter-clockwise. The worm wheel 120 is provided with a protrusion 200 that projects from the worm wheel 120 .
The fan-shaped output lever 130 is swingably supported by an output shaft 1310 disposed on one side of the worm wheel 120 . Precisely, the output lever 130 gradually broadens from a base 1320 of the output lever 130 towards a front end 1330 of the output lever 130 . The base 1320 is shaft-supported and the front end 1330 swings freely. A groove 300 into which the protrusion 200 of the worm wheel 120 engages is provided on the front end 1330 that faces the worm wheel 120 .
On the output shaft 1310 that shaft-supports the output lever 130 , an output arm 1340 is shaft-supported. The output arm 1340 moves in unison with the output lever 130 through the output shaft 1310 . The output arm 1340 is connected to a locking lever 140 which is a switching member. The locking lever 140 switches the door locking device between locked and unlocked condition by switching between a locked position and an unlocked position.
The actuator 100 electronically works in the manner described below when the door locking device is in a locked condition (that is, when the locking lever 140 is in the locked position). The driving motor 110 is driven to turn the worm wheel 120 in counter-clockwise direction. By this action the protrusion 200 of the worm wheel 120 engages in a first contact portion 300 a of the groove 300 of the output lever 130 . Once the worm wheel 120 and the output lever 130 are engaged in this fashion, further counter-clockwise rotation of the worm wheel 120 makes the protrusion 200 push the first contact portion 300 a and makes the output lever 130 swing counter-clockwise. The output lever 130 switches the locking lever 140 to the unlocked position through the output arm 1340 which turns in unison with the output lever 130 . Thus, the door locking device is in an unlocked condition. When the worm wheel 120 turns a complete 360 degrees and the protrusion 200 is back in its original position, the driving motor 110 ceases its operation.
The actuator 100 electronically works in the manner described below when the door locking device is in an unlocked condition (that is, when the locking lever 140 is in the unlocked position). The driving motor 110 is driven to turn the worm wheel 120 in clockwise direction. By this action the protrusion 200 of the worm wheel 120 engages in a second contact portion 300 b of the groove 300 of the output lever 130 . Once the worm wheel 120 and the output lever 130 are engaged in this fashion, further clockwise rotation of the worm wheel 120 makes the protrusion 200 push the second contact portion 300 b and makes the output lever 130 swing clockwise. The output lever 130 switches the locking lever 140 to the locked position through the output arm 1340 which turns in unison with the output lever 130 . Thus, the door locking device is in a locked condition. In this case too, when the worm wheel 120 turns a complete 360 degrees and the protrusion 200 is back in its original position, the driving motor ceases to be driven.
In the case of manual operation such as by insertion of key into the key cylinder or operation of the inside locking button, the locking lever 140 switches between the locked position and the unlocked position by a linking unit such as a link or a wire that links the locking lever 140 and the key cylinder or the inside locking button. The door locking device switches between locked and unlocked state in accordance with the locked or unlocked position of the locking lever 140 . The actuator works in the following manner under such circumstances. The output lever 130 swings in unison with the output arm 1340 in accordance with the locked or unlocked position of the locking lever 140 , while the protrusion 200 of the worm wheel 120 shifts in the groove 300 . As a result, the output lever 130 stops at a predetermined position. Consequently, the switching of position of the locking lever by manual operation does not get transmitted to the worm wheel 120 .
In the conventional actuator 100 , the protrusion 200 provided on the worm wheel 120 moves in the groove 300 provided in the output lever 130 upon manual operation or electronic control of the door locking device. Consequently, it is necessary to have a fan-shaped output lever 130 which is sufficiently broad. In addition, it is necessary to make the sliding area of the output lever 130 to also cover the area outside of the perimeter of the worm wheel 120 . Hence, the actuator cannot be made compact.
SUMMARY OF THE INVENTION
It is an object of the present invention to at least solve the problems in the conventional technology.
An actuator for a vehicle according to an aspect of the present invention includes a rotatable rotor; a lever that is disposed so as to be swingable between a first position and a second position; and an engagement mechanism through which the lever is engaged with the rotor, the engagement mechanism including a protrusion that engages with the rotor; and a guide mechanism that makes, along with rotation of the rotor, the lever swing between the first position and the second position, and allows, when the rotor stops rotating, a movement of the lever without turning the rotor.
The other objects, features and advantages of the present invention are specifically set forth in or will become apparent from the following detailed descriptions of the invention when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view illustrating the main parts of an actuator for a door locking device (an automobile part) according to the present invention;
FIG. 2 is a plan view illustrating the mechanism of the actuator;
FIG. 3 is a plan view illustrating the mechanism of the actuator;
FIG. 4 is a plan view illustrating the mechanism of the actuator;
FIG. 5 is a plan view illustrating the mechanism of the actuator;
FIG. 6 is a plan view illustrating the mechanism of the actuator;
FIG. 7 is a plan view illustrating the mechanism of the actuator; and
FIG. 8 is a plan view illustrating a conventional actuator.
DETAILED DESCRIPTION
Exemplary embodiments of an actuator for a vehicle according to the present invention will be explained below with reference to the accompanying drawings. For the sake of convenience, an actuator for a door locking device will be explained as a specific example of the actuator for an automobile door lock.
FIG. 1 is a plan view illustrating the main parts of the actuator for a door locking device (automobile part) according to the present invention. FIG. 2 through FIG. 7 are plan views illustrating the mechanism of the actuator shown in FIG. 1 . In FIG. 1 through FIG. 7 , the actuator 10 includes a driving motor 11 , a worm wheel 12 , and an output lever 13 .
The driving motor 11 is housed in a not shown casing and can turn both clockwise and counter-clockwise. The driving motor 111 is driven electronically, and has a driving shaft 111 and a cylindrical worm 112 mounted on the driving shaft 111 . The driving shaft 111 and the worm 112 turn in unison.
The worm wheel 12 is disc-shaped and is housed in a casing. The worm wheel 12 is rotatably supported by a supporting shaft 121 . One portion of the worm wheel 12 is engaged with the worm 112 . Consequently, the worm wheel 12 is a rotor that turns in a normal direction or the opposite direction through the worm 112 driven by the driving motor 11 . The worm wheel 12 is illustrated in FIG. 1 as a rotor that turns clockwise or counter-clockwise. A groove (an engaging guiding member) 30 , which is a part of an engaging unit, is formed on worm wheel 12 .
The output lever 13 is shaft-supported by an output shaft 131 disposed on a predetermined position on one side of the worm wheel 12 , and is swingable. Precisely, a base 132 of the output lever 13 is shaft-supported by the output shaft 131 disposed away from the driving motor 11 and the worm wheel 12 . A front end 133 of the output lever 13 swings freely. In other words, the output lever 13 slides between a first position in FIG. 1 and a second position in FIG. 7 . The output lever 13 shown in the drawings broadens gradually from the base 132 to the front end 133 . The base 132 is connected to a locking lever 14 which is a switching member. The locking lever 14 switches the door locking device between a locked position and an unlocked position. To be more specific, when the output lever 13 is at the first position (see FIG. 1 ), the locking lever 14 , which is connected to the output lever 13 , is in the unlocked position, and when the output lever 13 is at the second position (see FIG. 7 ), the locking lever 14 is in the locked position.
A protrusion 20 projects toward the worm wheel 12 from the portion of the front end 133 of the output lever 13 that faces the end facet of the worm wheel 12 . The protrusion 20 along with the groove 30 forms the engaging unit.
In the actuator 10 according to the present invention, the protrusion 20 on the output lever 13 moves within the groove 30 provided in the worm wheel 12 . The output lever 13 engages with the worm wheel 12 when the protrusion 20 engages into the groove 30 . The groove 30 includes a first sliding member 31 , a second sliding member 32 , a contact member 33 , a guiding member 34 , and an allowing member 35 . The first sliding member 31 has a first sliding surface 310 along the outer periphery of the worm wheel 12 , and the second sliding member 32 has a second sliding surface 320 along the outer periphery of the worm wheel 12 . The first sliding surface 310 and the second sliding surface 320 face each other with a supporting shaft 121 between them. When the worm wheel 12 turns, the first sliding member 31 and the second sliding member 32 slide and come in contact with the protrusion 20 of the output lever 13 and guide the protrusion 20 to the guiding member 34 and the allowing member 35 , respectively.
The contact member 33 is pinned on the worm wheel 12 by the supporting shaft 121 . The contact member 33 includes a first contact member 331 and a second contact member 332 which extend in different directions with respect to the supporting shaft 121 .
When the worm wheel 12 turns clockwise, the first contact member 331 attaches with the protrusion 20 of the output lever 13 and swings the output lever 13 counter-clockwise. The first contact member 331 is disposed in such a way that it does not attach with the protrusion 20 when due to the turning of the worm wheel 12 the protrusion 20 is moving along the second sliding surface 320 .
When the worm wheel 12 turns counter-clockwise, the second contact member 332 attaches with the protrusion 20 of the output lever 13 and swings the output lever 13 clockwise. The second contact member 332 is disposed in such a way that it does not attach with the protrusion 20 when due to the turning of the worm wheel 12 the protrusion 20 is moving along the first sliding surface 310 .
The guiding member 34 is disposed between and in continuation with the first sliding member 31 and the second sliding member 32 . When the worm wheel 12 turns clockwise, the guiding member 34 guides the protrusion 20 that slides from the first sliding member 31 so that the protrusion 20 comes in contact with the first contact member 331 , and when the worm wheel 12 turns counter-clockwise, the guiding member 34 guides the protrusion 20 that slides from the second sliding member 32 such that the protrusion 20 comes in contact with the second contact member 332 .
The allowing member 35 (allowing means) is disposed in continuation with the first sliding member 31 and the second sliding member 32 and facing the guiding member 34 , with the supporting axis 121 (the contact member 33 ) disposed in between. The allowing member 35 has an arc track R with the output shaft 131 as its center. The allowing member 35 allows the movement of the protrusion 20 of the output lever 13 when the output lever 13 slides between the first position and the second position at the time when the worm wheel 12 is not turning.
The actuator 10 that has the structure described above works in the manner described below when operated electronically and manually. An electronic control of the actuator 10 will be explained followed by explanation of manual operation. The electronic control refers to the so-called keyless entry involving usage of a remote controller for locking and unlocking the door locking device in a switchable manner.
As illustrated in FIG. 1 , the output lever 13 and the worm wheel 12 are engaged when the protrusion 20 at a position (hereinafter also “first halting position”) near the first sliding position 31 in the allowing member 35 of the groove 30 . When the output lever 13 and the worm wheel 12 are engaged, the output lever 13 is in the first position and the locking lever 14 which is connected to the output lever 13 is in the unlocked position. Consequently, the door locking mechanism is in the unlocked condition.
When the driving motor 11 is driven electronically, the worm wheel 12 turns clockwise through the driving shaft 11 and the worm 112 . When the worm wheel 12 turns a complete 360 degrees, the driving motor 11 ceases to be driven.
When the worm wheel 12 turns clockwise, as shown in FIG. 2 , the protrusion 20 of the output lever 13 moves along the first sliding surface 310 of the groove 30 of the worm wheel 12 . When the worm wheel 12 turns further clockwise, as shown in FIG. 3 , the protrusion 20 moves from the first sliding surface 310 to the guiding member 34 .
Upon further turning of the worm wheel 12 , as shown in FIG. 4 , the protrusion 20 that has moved to the guiding member 34 is further guided by the guiding member 34 to the first contact member 331 . The protrusion thus guided to the first contact member 331 comes in contact with the first contact member 331 by further turning of the worm wheel 12 , as shown in FIG. 5 . This action swings the output lever 13 counter-clockwise.
Upon further turning of the worm wheel 12 , the protrusion which is in contact with the first contact member 331 moves along the second sliding surface 320 , as shown in FIG. 6 , and comes in contact with the allowing member 35 , as shown in FIG. 7 . At this point, the worm wheel 12 completes a full 360 degrees, and stops turning. As a result, the driving motor 11 ceases to be driven. Consequently, the output lever 13 and the worm wheel 12 are engaged with the protrusion 20 of the output lever 13 at a position (hereinafter also “second halting position”) near the second sliding member 32 on the allowing member 34 of the groove 30 . The output lever 13 is thus in the second position. Therefore, the locking lever 14 , which is connected to the output lever 13 , switches to the locked position, thus leaving the door locking device in the locked state.
Explained below is the working of the actuator 10 when the door locking device changes from the locked to the unlocked condition electronically.
When the output lever 13 and the worm wheel 13 are engaged with the protrusion of the output lever 13 at the second halting position, or in other words, when the output lever 13 is in the second position, the driving motor 11 is electronically driven to turn the worm wheel 12 counter-clockwise. Due to the turning of the worm wheel 12 , the protrusion 20 of the output lever 13 moves along the second sliding surface 320 and reaches the guiding member 34 . Further turning of the worm wheel 12 , the protrusion 20 is guided by the guiding member 34 into the second contact member 332 . When the protrusion 20 comes in contact with the second contact member 332 , the output lever 13 swings clockwise. When the worm wheel 12 turns further, the protrusion 20 moves along the first sliding surface 310 and comes in contact with the allowing member 35 . With this, the worm wheel completes a full 360 degrees turn and stops turning. As a result, the driving motor 11 ceases to be driven. Consequently, the output lever 13 and the worm wheel 12 are now engaged with the protrusion 20 of the output lever 13 at the first halting position. The output lever 13 is thus in the first position. Therefore, the locking lever 14 , which is connected to the output lever 13 , switches to the unlocked position, thus leaving the door locking device in the unlocked state.
The working of the actuator 10 when operated manually will be described next. Manual operation refers to using a key on the externally provided key cylinder or from within the chassis by pushing a locking button provided inside in order to lock and unlock the door locking device in a switchable manner. Precisely, the door locking device is rendered in a locked or unlocked state in a switchable manner by switching the position of the locking lever 14 between the locked and unlocked position.
In the case of manual operation, the driving motor 11 of the actuator 10 is not driven and hence the worm wheel also does not turn. Therefore, while the locking lever 14 is switched between the unlocked and the locked position by manual operation, the output lever 13 which is connected to the locking lever 14 slides between the first position and the second position.
When the locking lever 14 is in the unlocked position (that is, when the door locking device is in the unlocked state), the output lever 13 of the actuator 10 is in the first position as shown in FIG. 1 , and the protrusion 20 is in the first halting position.
When the locking lever 14 is switched from the unlocked position to the locked position by manual operation, the output lever 13 swings counter-clockwise. In other words, the output lever 13 slides from the first position to the second position. When the output lever 13 slides, the protrusion 20 of the output lever 13 slides along the arc track R from the first halting position to the second halting position and stops there.
When the locking lever 14 is switched from the locked position to the unlocked position by manual operation, the protrusion 20 of the output lever 13 slides along the arc track R from the second halting position to the first halting position and stops there. This sliding of the protrusion 20 is not transmitted to the worm wheel 12 . Consequently, the manual switching of the locking lever between the locked and unlocked position can be carried out smoothly.
To sum up, in the actuator 10 according to the present invention, by providing a mechanism in which the protrusion 20 provided in the front end 133 of the output lever 13 engages into and slides in the groove 30 provided on the end facet of the worm wheel 12 and thereby engaging the output lever 13 and the worm wheel 12 , a compact output lever 13 can be realized since the width of the output lever 13 need not exceed the size of the protrusion 20 .
In the actuator 10 according to the present invention, by providing a mechanism in which the protrusion 20 provided in the front end 133 of the output lever 13 engages into and slides in the groove 30 provided on the end facet of the worm wheel 12 and thereby engaging the output lever 13 and the worm wheel 12 , the sliding area of the output lever 13 can be restricted within the perimeter of the worm wheel 12 . Consequently, the actuator 10 can be made compact.
In the actuator 10 according to the present invention, the locking lever 14 can be switched between the locked and unlocked state by the turning of the worm wheel 12 to a full 360 degrees and by the sliding of the output lever 13 that engages with the worm wheel 12 . Consequently, the need for an elastic body such as a spring, and the like, for returning the worm wheel 12 to a neutral position is obviated.
Although the invention has been described with respect to a specific embodiment for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art which fairly fall within the basic teaching herein set forth. | An actuator for a vehicle, in particular for an automobile door lock includes a rotatable rotor; a lever that is disposed so as to be swingable between a first position and a second position; and an engagement mechanism through which the lever is engaged with the rotor. The engagement mechanism also includes a protrusion that engages with the rotor; and a guide mechanism that makes, along with rotation of the rotor, the lever swing between the first position and the second position, and allows, when the rotor stops rotating, a movement of the lever without turning the rotor. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 60/856,676, filed Nov. 3, 2006, the disclosure of which is incorporated by reference herein in its entirety.
TECHNICAL FIELD
The present invention relates to movable partitions and, more particularly, to systems, apparatuses and methods for reducing or eliminating fluid flow across such movable partitions.
BACKGROUND
Movable partitions are utilized in numerous situations and environments for a variety of purposes. Such partitions may include for example, foldable or collapsible doors configured to close-off an opening in order to enclose a room or to subdivide a single large room into one or more smaller rooms. The subdivision of a larger area may be desired, for example, to accommodate the simultaneous meeting of multiple groups. In such applications movable partitions are useful, among other things, for providing privacy and noise reduction.
Movable partitions may also be used to act as a security barrier, a fire barrier or as both. In such a case, the movable partition may be configured to automatically close upon the occurrence of a predetermined event such as the actuation of an associated alarm. For example, one or more movable partitions may be configured as a fire door or barrier wherein each door is formed with a plurality of panels connected to each other by way of hinge mechanisms. The hinged connection of the panels allows the door to fold-up in a compact unit on one side of the opening or it may be stored in a pocket formed within a wall, the pocket being designed to conceal the door and preserve the aesthetics of the room in which the door is installed. When deployment of the door is necessary, the door is driven by a motor along a track (the track often being incorporated into the header above the door), until the leading edge of the door, often defined by a component called the lead post, complementarily engages a mating receptacle. Such a mating receptacle may be referred to as a jamb or a door post when formed in a fixed structure (such as a wall), or as mating lead post when formed in another door or movable partition. The lead post, when properly engaged with the door jamb (or the mating lead post), allows corresponding latching mechanisms to engage if desired, and helps to provide a desired seal (e.g., a seal with respect to airflow, sound waves or both).
However, even when a movable partition is properly closed, due to the various and numerous moving components associated with a movable partition, the movable partition may not always provide the desired level of “seal” from one side of the deployed movable partition to the other. In other words, fluid flow through one or more locations may reduce the effectiveness of the door to act, for example, as a smoke barrier or a sound barrier.
Some efforts have been made to prevent the lateral displacement of the lower edge of such a movable partition to prevent fluid flow beneath the movable partition. For example, U.S. patent application Ser. Nos. 11/097,101 entitled METHOD, APPARATUS, AND SYSTEM FOR DIRECTIONALLY CONTROLLING A MOVABLE PARTITION, 11/796,325 entitled METHOD, APPARATUS AND SYSTEM FOR CONTROLLING A MOVABLE PARTITION, and Provisional Application No. 60/856,957 entitled MOVABLE PARTITIONS WITH LATERAL RESTRAINT DEVICES AND RELATED METHODS (the disclosures of each of which are hereby incorporated by reference in their entireties) discuss various means of reducing or preventing the lateral displacement of the lower edge of a movable partition.
However, even if the lower edge of a movable partition is restrained, “leaks” across the partition may still occur at various locations. In certain circumstances, such “leaks” may individually represent a relatively small flow of air or other fluid across the partition, but the cumulative effect of such leaks can be deleterious to the performance of the partition regardless of whether the partition is being used, for example, as a smoke barrier or a sound barrier.
Reduction in fluid flow across a partition, such as a movable partition used as, for example, a fire, smoke, security or sound barrier in order to make such apparatuses and systems more effective and more efficient is a continued pursuit of the industry.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to movable partitions, components for movable partitions, systems including movable partitions and related methods. In accordance with one embodiment of the present invention, a track and trolley system for a movable partition is provided. The system may include a track having a central channel extending longitudinally therethrough, a first outer channel located on a first lateral side of the central channel and a second outer channel located on a second lateral side of the central channel. One or more rollers may be coupled to a frame member. The frame member and the roller or rollers may each be disposed in the central channel and longitudinally displaceable relative to the track.
Additionally, the track and trolley system may be configured such that the central channel defines a pathway for a drive chain and such that the frame member and the roller or rollers are located and configured to avoid interference with the pathway.
In accordance with another embodiment of the present invention, a track for a movable partition is provided. The track may include a structure having at least one elongated channel formed therein and defining a longitudinally extending opening in a surface of the structure. A first seal component may have a seal lip that extends at least partially across the opening in a first lateral direction. A second seal component may further have a seal lip extending at least partially across the opening in a second lateral direction. The seal components may be configured such that their respective seal lips are contiguous with one another or such that they laterally overlap.
In accordance with yet another embodiment of the present invention, a movable partition is provided. The movable partition may include a track having at least one elongated channel formed therein and defining a longitudinally extending opening in a surface of the channel. A first seal component may include a seal lip that extends at least partially across the opening in a first lateral direction and a second seal component may have a seal lip that extends at least partially across the opening in a second lateral direction. A plurality of panels is hingedly coupled to one another to form a plicated structure and at least one pin is coupled to at least one panel of the plurality of panels. The pin may extend from the at least one panel, through the opening and into the at least one elongated channel. At least one roller may be coupled to the at least one pin and disposed in the at least one elongated channel.
In another embodiment of the movable partition, at least one channel may include a first channel and a second channel with a central channel being located between the first channel and the second channel. The movable partition may further include a trolley including a frame member having a web member, a first leg on a first side of the web member and a second leg member on a second side of the web member. A first roller may be coupled to the first leg and a second roller may be coupled to the second leg. The frame member, the first roller and the second roller may each be disposed in the central channel and longitudinally displaceable relative to the track.
In accordance with yet another embodiment of the present invention, another movable partition is provided. The partition includes a first plicated structure having a plurality of hingedly coupled panels and a second plicated structure having a plurality of hingedly coupled panels. A track includes a central channel extending longitudinally therethrough, a first outer channel located on a first lateral side of the central channel and a second outer channel located on a second lateral side of the central channel. The first plicated structure is associated with the first outer channel and the second plicated structure is associated with the second outer channel. A trolley comprising a frame member and at least one roller coupled to the frame member are disposed in the central channel and longitudinally displaceable relative to the track.
In accordance with a further embodiment of the present invention, another movable partition is provided. The movable partition includes a plurality of panels hingedly coupled to one another to form a plicated structure. A layer of insulation is disposed on a surface of the plicated structure and at least one fastening apparatus is coupled to at least one panel of the plurality of panels, the at least one fastening apparatus being located and configured to substantially fix the layer of insulation relative to the plicated structure. A layer of sealant is configured and located to substantially fluidly seal the layer of insulation and the plurality of panels.
In accordance with yet another embodiment of the present invention, a method of operating a movable partition is provided. The method includes suspending a first plicated structure having a plurality of panels from a first channel of a track and suspending a second plicated structure having a plurality of panels from a second channel of the track. A trolley is at least partially disposed in a third channel of the track, wherein the third channel of the track is disposed between the first and second channels. A first fluid seal is substantially formed between the first plicated structure and a surface above the first plicated structure and a fluid seal is substantially formed between the second plicated structure and a surface above the second plicated structure. The trolley is longitudinally displaced along the track while the trolley is maintained within an envelope defined by the first fluid seal and the second seal.
Various other embodiments of the invention are described herein and will become apparent to one of ordinary skill in the art upon reading of the detailed description.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The foregoing and other advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:
FIG. 1 is a perspective view of a system and movable partition in accordance with an embodiment of the present invention;
FIG. 2 is a plan view of the partition shown in FIG. 1 ;
FIG. 3 a perspective view of a movable partition shown in FIGS. 1 and 2 with various components and sections stripped away to show certain details in accordance with an embodiment of the present invention;
FIG. 4 is an end view of an overhead track used in certain embodiments of the present invention;
FIG. 5 is a partial cross-sectional view of a prior art device;
FIG. 6 is a perspective view of a trolley in accordance with an embodiment of the present invention;
FIG. 7 is a partial cross-section view of an overhead track and a trolley in accordance with an embodiment of the present invention;
FIG. 8 is an end view of a seal component in accordance with an embodiment of the present invention;
FIG. 9 is a perspective view of the inside surface of a set of panels used to form a movable partition in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 through 3 , a system 100 is shown which includes a movable partition, for example, in the form of an accordion-type door 102 . The door 102 may be used, for example, as a security and/or fire door. In other embodiments, the door 102 need not be utilized as a fire or security door, but may be used, for example, for the subdividing of a larger space into smaller rooms or areas or it may be used as a sound barrier. The door 102 may be formed with a plurality of panels 104 that are connected to one another with hinges 106 or other hinge-like members. The hinged connection of the individual panels 104 enables the panels 104 to fold relative to each other in an accordion or a plicated manner such that the door 102 may be compactly stored in a pocket 108 formed in a wall 110 A of a building when in a retracted or folded state.
When it is desired to deploy the door 102 to an extended position, for example, to secure an area such as an elevator lobby 112 during a fire, the door 102 is displaced along a track 114 and across the space to provide an appropriate barrier. When in a deployed or an extended state, a leading edge of the door 102 , shown as a male lead post 116 , complementarily or matingly engages with a jamb or door post 118 ( FIG. 2 ) that may be formed in a wall 110 B of a building. As can be seen in FIG. 2 , an accordion-type door 102 may include a first accordion-style partition 102 A and a second accordion-style partition 102 B which is laterally spaced from the first partition 102 A (it is noted that only one panel is shown in FIG. 3 for purposes of convenience and clarity in describing embodiments of the invention). Such a configuration may be utilized, for example, as a fire door wherein one partition 102 A may act as a primary fire and smoke barrier, the space 122 between the two partitions 102 A and 102 B may act as an insulator or a buffer zone, and the second partition 102 B may act as a secondary fire and smoke barrier. Such a configuration may also be useful in providing an acoustical barrier when the door 102 is used to subdivide a larger space into multiple, smaller rooms.
A drive, which may include, for example, a motor 124 and a transmission member such as a drive belt or chain 125 ( FIG. 2 ), may be configured to open and close the door 102 upon actuation thereof. A trolley 128 is coupled to a portion of the chain 125 and configured to ride or slide along the track 114 . The trolley 128 may be coupled to, for example, the lead post 116 such that displacement of the trolley 128 results in corresponding displacement of the lead post 116 and the various panels 104 attached thereto. Referring briefly to FIG. 4 , an end view of a track 114 is shown which may be used in accordance with an embodiment of the present invention. A first channel 130 may be configured for receipt of slide mechanisms or rollers 132 ( FIGS. 3 and 7 ) that may be attached to individual panels 104 associated with a first partition (e.g., partition 102 A) while a second channel 134 may be configured for receipt of similar slide mechanisms or rollers associated with a second partition (e.g., partition 102 B). A central channel 136 may be disposed between the two partition channels 130 and 134 and may be configured for receipt of the trolley 128 as well as provide a raceway for the belt or chain 125 .
Referring back to FIGS. 1 through 3 , the door system 100 may further include various sensors and switches to assist in the control of the door 102 through appropriate connection with the motor 124 (such as by way of an appropriate controller as will be appreciated by those of ordinary skill in the art). For example, as shown in FIG. 1 , when used as a fire door, the door 102 may include a switch or actuator 126 , commonly referred to as “panic hardware.” Actuation of the panic hardware 126 enables a person located on one side of the door 102 to cause the door to open if it is closed, or to stop the door 102 while it is closing, allowing access through the barrier formed by the door 102 for a predetermined amount of time.
It is noted that, while the presently described embodiment is more specifically directed to a single accordion-type door 102 , other movable partitions may be utilized. For example, a two-door, or bi-part door, system may be utilized wherein two similarly configured doors extend across a space and join together to form an appropriate barrier. Also, the present invention is applicable to movable partitions or barriers other than the accordion-type doors that are specifically shown and described herein.
Referring briefly now to FIG. 5 , a partial cross-sectional view is shown of portions of a prior art device including a track 200 and a trolley 202 for a lead post. FIG. 5 also includes portions that are not part of the prior art device, which are shown in dashed lines. The trolley 202 includes a frame member 204 having rollers 206 coupled to laterally spaced ends thereof. The track 200 includes a central channel 214 in which a portion of the trolley 202 is disposed, and which acts as a raceway for a drive chain (chain not shown in FIG. 5 ). A first channel 210 is located on a first side of the track 200 and receives a first set of rollers 206 of the trolley 202 . A second channel 212 is located on an opposing side of the track 200 and receives a second set of rollers 206 of the trolley 202 . The central channel 214 is disposed between the first and second channels 210 and 212 and provides a raceway for a drive belt or drive chain as well as receives a portion of the trolley 202 such as a structure that may be coupled to the drive chain or a structure that may act as a chain (or belt) tensioner or idler.
As also shown FIG. 5 , as parts that are not part of the prior art device, but are used to illustrate possible hinged panels 216 (superimposed in dashed lines for purposes of clarity) as they may be used with the prior art device of FIG. 5 . In this possible implementation, a flexible seal component 218 is located at the upper portion of the panels and is intended to be in contact with the track 200 and ceiling or other supporting structure to which the track 200 is affixed. However, because the frame member 204 of the trolley extends across the centerline of each the first and second channels 210 and 212 , and therefore across the centerline 220 of each pathway of the suspended panels 216 , the frame member 204 of the trolley 202 penetrates through the region in which the flexible seal component 218 is disposed and causes the flexible seal to be displaced away from the track 200 (as indicated by dashed lines 222 ) and creates a significant gap 224 through which fluid flow may occur. The gap 224 allows a certain amount of air, smoke or noise to pass across the partitions 216 . In accordance with one embodiment of the present invention, the gaps 224 created by the prior device are substantially reduced or eliminated to improve the ability to seal a door and prevent, or at least minimize, fluid flow from one side of the door to the other.
Referring now to FIGS. 6 and 7 (with general reference to FIGS. 1 through 4 ), an embodiment of the present invention is shown regarding a track 114 and trolley 128 arrangement. The trolley 128 may include a frame member 140 having a web portion 140 A and two downwardly extending leg portions 140 B and 140 C. One or more rollers 142 A may be coupled to the first leg portion 140 B and one or more rollers 142 B may be coupled to the second leg portion 140 C. It is noted that, in the embodiment depicted by FIGS. 6 and 7 , the frame member 140 is oriented and configured substantially opposite to that of the prior art device described with respect to FIG. 5 . In other words, the legs of the frame member used in the prior art device extended substantially upward from the web member of the frame in contrast with the embodiment described with respect to FIGS. 6 and 7 . While the orientation described with respect to FIGS. 6 and 7 may provide certain advantages, the prior art orientation may also be utilized in conjunction with the present invention.
When installed in the track 114 , the rollers 142 A and 142 B are disposed in the central channel 136 of the track 114 . This is in contrast with the prior art device which was configured such that the rollers associated with the frame member were disposed in the laterally outward partition channels and not in the central channel. By configuring the frame member 140 and the associated rollers 142 A and 142 B such that the rollers 142 A and 142 B are located within the central channel 136 , there is no structural member or other component of the trolley 128 that extends beyond the centerline 144 of either of the first or second channel 130 and 134 (and, thus, of the corresponding centerline path of each partition 102 A and 102 B or individual panels 102 thereof).
Because there are no components extending through the centerline 144 , the flexible seal components 146 located at the top of the panels 102 remain in substantial contact with the track 128 and the ceiling 148 or other structure in which the track 128 may be installed, eliminating the gaps created by the prior art device previously described with respect to FIG. 5 .
It is further noted that the embodiment shown and described with respect to FIGS. 6 and 7 still maintains the ability for the chain 125 (or drive belt) to pass through the channel 136 without interference with the trolley 128 . Additionally, the reduced width of the frame member 140 and corresponding positioning of the rollers 142 A and 142 B (or sliding structures or other mechanisms) provides increased stability to the lead post 116 which is attached to the trolley 128 (e.g., by way of frame components 143 ) due to the reduced bending of the frame member 140 and corresponding lateral displacement of the lead post 116 . Indeed, the configuration of the trolley 128 in conjunction with its cooperative positioning within the central channel 136 of the track 114 enables the trolley to support a greater load as compared to the previously described prior art device.
Referring briefly back to FIG. 4 in conjunction with FIG. 7 , another embodiment of the present invention is shown and described. As already described, a number of the panels 102 of the partitions 102 A and 102 B (in some embodiments, all of them) have rollers 132 or slide mechanisms attached to them to support them from the first and second channels 130 and 134 of the track 114 . The rollers 132 may be coupled to the panels 104 by way of a pin 150 or other similar structure fastened to the panel 102 . The pins 150 , since they extend between the panels 102 and the channels 130 and 134 in which the associated rollers 132 are disposed, provide another point of potential leakage or fluid flow across the partitions 102 A and 102 B of the door 102 . Because each panel 102 straddles the centerline 144 of an associated channel 130 and 134 from which they are supported, fluid flow may occur from a location exterior to the partition (e.g., partition 102 A), into the associated channel (e.g., 130 ) and into the space 122 ( FIG. 2 ) between the two partitions 102 A and 102 B. Fluid flow may then occur across the other partition (e.g., partition 102 B) in a similar manner.
In one embodiment of the present invention, seal components 152 are installed in association with the channels 130 and 134 of the track 114 to further reduce fluid flow across the door 102 . Referring briefly to FIG. 8 , an example of a seal component 152 is shown. The seal component 152 may include an L-shaped component, such as shown, or may exhibit various other cross-sectional configurations. Example dimensions of a seal component 152 according to one embodiment include the following: dimension A may be approximately 0.335 inch (approximately 8.5 millimeters (mm)); dimension B may be approximately 0.375 inch (approximately 9.5 mm); dimension C may be approximately 0.04 inch (approximately 1 mm); dimension D may be approximately 0.4 inch (approximately 10 mm); dimension E may be approximately 0.963 inch (approximately 24 mm); dimension F may be approximately 0.015 inch (approximately 0.04 mm) and R may be approximately 0.04 inch (approximately 1 mm). However, such dimensions are merely examples and it will be appreciated by those of skill in the art that other configurations may be utilized. The seal component 152 includes a seal lip 154 which is substantially flexible and is substantially elastically deformable. In one embodiment, such a seal component may be formed of a material such as polyvinylchloride (PVC), although other materials may be utilized.
As seen in FIG. 4 , two such seal components may be utilized in conjunction with a channel (e.g., channel 130 ) with the seal lips 154 of each seal component being substantially contiguous with each other or even overlapping each other by a desired dimension. The seal components 152 may be installed, for example, using an adhesive material 156 ( FIG. 8 ) disposed between the seal component 152 and the track 114 .
The pins 150 associated with the panels 104 protrude through the seal formed by the seal components 152 causing the seal lips 154 to deflect as indicated in FIG. 7 . The seal components 152 substantially wrap around the pins 150 and, when the pins 150 are displaced along the track (such as when the door 102 is deployed or retracted), the seal lips 154 return to their normal position such as shown in FIG. 4 in the absence of such pins 150 . Thus, the seal components 152 serve to minimize fluid flow that may otherwise occur across a partition (e.g., 102 A) by way of the associated channel (e.g., channel 130 ).
Referring now to FIG. 9 , another embodiment of the present invention is shown and described. One or more layers of insulation 160 may be disposed on or adjacent an inner surface 162 of the partition 102 A (i.e., the surface of the partition located within the space 122 of the door 102 ). For example, a layer of fiberglass insulation 160 having a foil backing may be installed near the upper edge of the partition 102 A. Clips 164 or other fasteners may be used to fix the insulation 160 in place relative to the panels 104 . However, even with the clips 164 or other fasteners holding the insulation 160 in place, fluid flow may occur along a path traveling between the insulation 160 and the individual panels 104 . To prevent or minimize such fluid flow, a sealant, such as a foil tape 166 may be placed over an edge of the insulation 160 and also adhered to the inner surface 162 of the partition 102 A. Other means of sealing may likewise be used to form a seal between the insulation 160 and the inner surface of the partition 102 A.
While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims. | Movable partitions and various components for use with movable partitions are disclosed along with related systems and methods. In one embodiment, a track and trolley system for use with a movable partition is described. In one embodiment, the track and trolley system may include a track having three channels wherein a first partition is suspended from the first channel, a second partition is suspended from the second channel, and a trolley is partially disposed in the third channel and between the first and second channels. Seal components may be used to substantially provide a fluid seal between the partitions and a surface from which the partitions are suspended. The trolley is configured to be longitudinally displaceable along the third channel while maintaining its components within an envelope defined by the seal components. In other words, such seal components are not penetrated or otherwise breached by the displaced trolley. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a national stage application based International Application No. PCT/EP99/10394, filed Dec. 27, 1999, which claims priority from German Application No. 198 60 892.6, filed Dec. 31, 1998, and German Application No. 199 07 995.1, filed Feb. 25, 1999.
BACKGROUND OF THE INVENTION
The invention relates to a system for monitoring supply lines, such as gas lines laid underground.
In the prior art, gas supply lines are monitored with the aid of a measuring group, comprising a path finder and a tracer. Such measuring groups carry out checks on the gas supply lines for their tightness at regular intervals, on account of the statutory monitoring obligation of the power supply companies.
The actual activity of such a measuring group consists in patroling the gas supply lines and determining a possible escape of supply gas by using a gas tracing instrument. The course of gas supply lines, generally laid underground, is naturally not readily detectable, so that a pathfinder, as a part of the measuring group, is responsible for the proper following of the measuring path. The gas tracing instrument is guided by the “tracer” in accordance with the navigation instructions from the pathfinder.
This procedure is relatively complicated, since the pathfinder, in the initial part of the monitoring operation, has to draw up extracts from maps and work out a suitable tracing path. During the measuring operation, the pathfinder is normally responsible for monitoring the completeness of the measurement and recording the measured results.
In this case, the line sections inspected are marked in writing with the points of note relevant to the operation of the line system. The recordings are used with respect to the responsible inspecting authorities as proof of the monitoring obligation placed by statute on the power supply company.
In the procedure described above, the use of at least two persons is absolutely necessary.
Furthermore, the reliability of the measurement depends both on the care of the pathfinder and the care of the tracer. For example, it is conceivable for the pathfinder, in the event of an inaccurate procedure, to deviate from the measurement path necessary for the verification of a gas escape and, as a result, a gas escape location will be overlooked. In addition, there is the risk of information losses arising from incomplete or faulty recording of the monitoring results.
BRIEF SUMMARY OF THE INVENTION
The invention is, then, based on the object of providing a monitoring system which avoids the aforementioned disadvantages and permits reliable monitoring.
The problem is solved by the independent claim 1 . Advantageous embodiments are reproduced in the subclaims.
In detail, the problem of the invention is solved by a mobile measuring device being combined with an electronic guidance system which preferably has recourse to existing satellite-assisted navigation system in conjunction with a geographical information system for generating the navigation information.
Particular preference is given to a combination of a mobile measuring device with navigation system with automatic documentation of the measured results and/or acoustic or optical guidance of the operator by using the navigation data determined.
With the aid of the measuring device according to the invention, the monitoring operation can be carried out by a single person. By using the computer-controled navigation and documentation, the monitoring becomes largely independent of the reliability of the operator.
A particular advantage consists in the fact that the safety of the operator during the monitoring operation is increased considerably. Because of the actual course of the gas line, it is often necessary to inspect locations at risk from traffic during a monitoring operation. The fact that substantial monitoring functions are performed by the mobile device permits the operator to direct his concentration to avoiding hazards during the inspection. In particular if an acoustic guidance system is used, the concentration potential of the operator is largely free and is therefore available, for example, for avoiding hazards.
A recording of the track of the path patroled, as implemented by one embodiment of the measuring device, provides the advantage of permitting exact local allocation of the measured values.
In the following text, the invention will be described in detail using an exemplary embodiment illustrated in the drawing, in which:
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 shows a mobile measuring device according to the invention;
FIG. 2 shows a flow diagram of a monitoring inspection with the aid of the measuring device according to the invention;
FIG. 3 shows a flow diagram of a first-time determination of a track with the aid of the measuring device according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
The mobile measuring device 1 comprises a frame 2 having rollers 4 , 6 and a guide arm 8 with a guide handle 10 . Arranged on the frame are measuring electronics 12 with satellite and dead-reckoning navigation devices, gas testing devices and a power supply. In addition, the frame has an antenna 14 to receive satellite and correction data, and also a table 16 arranged in the area of the guide arm 8 and having a computing unit 18 .
The frame is equipped with three running wheels, the central running wheel 6 being used at the same time as a measuring wheel for the distance and being connected to the computing unit.
The computer is arranged on the table in such a way that the operator, when guiding the mobile measuring device 1 at the handle 10 can read data displayed on the monitor 20 of the computer 18 during the inspection. The computer 18 also has a device for transmitting an acoustic signal to the operator.
For the purpose of determining position with the aid of the satellite navigation device 12 and the antenna 14 , recourse is initially made to existing satellite navigation systems, such as GPS (USA) and Glonass (Russia). A differential method is added to the aforementioned systems in order to increase the accuracy of the location determination. For this purpose, recourse can be made to correction methods which are already available, such as the SAPOS-HEPS real-time positioning system of the German land survey offices or a known reference station of the power supply company or line operator. If the accuracy of the pure satellite navigation position is adequate, the system may also be operated without reference points.
In order to bridge brief outages during the reception of the satellite signals, the use of an additional dead-reckoning navigation system is advantageous. With the latter system, the last position determined by the satellite system is extrapolated in terms of magnitude and direction by means of a distance vector until the satellite system supplies reliable data again.
The magnitude of the distance vector can be recorded, for example, by means of sensors in the measuring wheel 6 . An indirect distance measurement can be achieved with the aid of speed sensors, by means of simple integration of the measured signal. A further indirect possibility for measuring the distance consists in the double integration of the measured signal from an acceleration transmitter.
The direction of the distance vector can be obtained directly via an electronic compass or indirectly via an orthogonal pair of speed sensors. In addition, an inertia measuring system, for example in the form of a gyroscope or a two-axis orthogonal acceleration sensor, can be used to record the direction.
For the purpose of navigating the gas tracing instrument, use is preferably made of a geographic information system which is matched to the actual conditions of the area being monitored. It permits the position information to be linked to the topographic information about the area being monitored. Initialization of the position measuring system is needed as a basis for this linking. For this purpose, use may be made of correction data from external providers or correction data determined with the aid of dedicated stations at points whose coordinates are known. Also suitable is the determination of correction data by means of the operation of reference stations arranged in any desired way in the environment of such points. The coordinates of the reference station are then determined by means of measurements with reference to at least one point whose coordinates are known.
The aforementioned initialization methods supply positioning coordinates in a reference system which is defined mathematically uniquely, such as WGS 84 , which may be converted into real topographical information via appropriate transformation formulations.
The topographical information needed for navigation can be derived from existing network information systems from the power supply companies and, before the beginning of the inspection, can be transmitted to the computer unit 18 for the area to be examined.
The control path to be patroled does not have to agree with the actual course of the supply lines. This is particularly the case in gas lines which are laid under sealed surfaces, since an escape of gas can be measured only in the edge regions of the sealed surface.
After being input into the computer unit 18 , specialist information of this type is balanced with the positioning and distance data and taken into account in the guidance of the operator by means of the measuring device according to the invention. This can be carried out, for example, by means of integration of a digital track into the system. The track may be derived from available data and knowledge and entered into the computer unit 18 .
A particular advantage of the measuring device according to the invention is that it permits automatic track recordings. The track, for example recorded within the context of a first inspection, can be used for all subsequent measurements.
FIG. 2 illustrates a flow diagram of the inspection over a gas line using the device according to the invention, while FIG. 3 illustrates a flow diagram of a recording of a digital track in the course of the first inspection.
In the procedure illustrated in FIG. 2, the operator is guided along the track predefined by the computer. In the process, the computer takes into account a tolerance band to the left and right of the desired path, and if this path is left, this is pointed out, and the operator, if this is intended, must react with an input of the reason for leaving the desired path. This reason is in turn processed in the documentation system of the computer unit and may be available during the next inspection.
In the event of an increased gas concentration being determined by the gas tracing instrument, the operator is given specific, standardized instructions in order to ensure reproducible documentation of the gas escape.
It is particularly advantageous to use a cable-free earpiece/microphone combination for the communication between the operator and computer unit, in addition to the display, loud speaker and keyboard. By means of these measures, the concentration of the operator is largely released for other tasks.
Overall, the invention therefore permits secure line monitoring with a low outlay on personnel. | The invention relates to a mobile measuring device that monitors potential leaks of gas conduits. The device includes a navigation system. | 5 |
BACKGROUND OF THE INVENTION
The invention is based on a fuel injection nozzle in which a fuel conduit leads via a filter body located in the nozzle housing to an injection valve at the injection ports, and a check valve which is installed in the fuel conduit and opens in the direction of fuel flow. This check valve may be provided in order to maintain a certain static pressure in the injection nozzle, so that when the injection valve closes combustion gases are prevented from reaching its valve seat and contaminating it. This could happen, for instance, in injection systems intended for small, high-speed motors in which the buildup of fuel pressure takes place very quickly following the end of injection. The check valve may additionally serve as a relief means and for receiving the positively-displaced fuel volume, thereby preventing the after-injections this fuel volume causes.
In a known injection nozzle of the type generally described above (German Pat. No. 715 51), the check valve is built into the fuel conduit directly, and the valve seat and the support surface for the closing spring are embodied on adjacent parts of the nozzle housing. This kind of embodiment makes the final assembly of the injection nozzle difficult, because additional care must then be taken that the valve elements are inserted correctly, and it may even be necessary to take measures to prevent the valve elements from falling out unintentionally from the hollow spaces provided in the nozzle housing for receiving them.
OBJECT AND SUMMARY OF THE INVENTION
The apparatus according to the invention and having the characteristics of the main claim has the advantage over the prior art that the check valve and the filter body represent a single functional group, which can be assembled beforehand as a unit and then inserted or pressed into the nozzle housing, for instance into the nozzle holder. As a result, the final assembly of the injection valve becomes substantially simplier, and the further advantage is attained that the exact bores and fittings of the check valve can be disposed on the relatively small filter body, independently of the nozzle housing.
As a result of the characteristics disclosed, advantageous further embodiments of the apparatus disclosed can be attained.
The closing member of the check valve can also, when disposed in the filter body, be embodied as a relief piston, in order to receive the displacement volume of the injection valve and prevent after-injections.
The embodiment of the filter body as a linear-type filter which is inserted into the fuel conduit and which together with the surrounding walls of the fuel conduit defines filter gaps is particularly well suited for the installation of a check valve.
Th structural characteristics result in a compact realization of the filter body, in which the check valve, which may also be assigned a relief function, does not impair the filtering effect.
The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of a preferred embodiment taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an injection nozzle in longitudinal section, having a rod-type filter embodied in accordance with the invention;
FIG. 2 shows the rod-type filter of FIG. 1 on an enlarged scale and in an upright position;
FIG. 3 is a section taken along the line III--III of FIG. 2; and
FIG. 4 is a section taken along the line IV--IV of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The injection nozzle has a nozzle body 10 which together with a shim 11 is firmly fastened to a nozzle holder 14 via a tensioning nut 12. The nozzle body 10, in the conventional manner, contains a valve needle 17 which is displaceable counter to the force of a closing spring 16, the valve needle 17 monitors a valve seat which is disposed in the nozzle body 10 preceding injection ports 18. The nozzle holder 14 contains a fuel inflow conduit, which comprises three bore segments 20, 22, 24 of differing diameters. The bore segment 24 corresponds with a conduit 25 in the nozzle body 10, which discharges into a pressure chamber surrounding the valve needle 17. In the vicinity of the pressure chamber, the valve needle 17 is provided with a pressure shoulder, and the pressure chamber communicates via an annular chamber between the valve needle 17 and the bore of the nozzle body 10 with the valve seat. The valve needle 17 is displaced by the pressure of the inflowing fuel counter to the force of the closing spring 16, as a result of which the valve is opened and the fuel travels to the injection ports 18. The leakage oil entering the chamber 26 receiving the closing spring 16 is carried via a further bore 28 to a fitting, not visible in the drawing, intended for effecting the connection of a leakage oil line.
A linear-type filter body 30 is inserted into the bore segment 20 of the fuel inflow conduit, forcing the inflowing fuel to pass through narrow gaps formed between the shaped outer periphery of the filter body 30 and the surrounding wall 31 of the bore segment 20. The fuel is thereby filtered, and any dirt particles, chips and the like carried along with it which are beyond a predetermined size are restrained there.
Going into detail, the filter body 30 is provided at each of its two ends which a collar 32, 34 (FIG. 2), between which a middle segment 36 of slightly reduced diameter is located. The two collars 32, 34 fill up the bore segment 20 in the nozzle holder 14 completely in a fitting manner and thus hold the filter body 30 firmly therein by frictional force. As a result of this embodiment of the filtered body 30, an annular chamber 38 is formed between its middle segment 36 and the bore wall 31 of the nozzle holder 14, by way of which annular chamber 38 the fuel must pass in the manner to be described in further detail below.
The filter body 30 is provided with a longitudinal bore 40 extending all the way therethrough, into which a hollow screw 42 is inserted on the inflow side and which is closed off at the output side by a threaded plug 44. The hollow screw 42 is provided with an axial extension 46 and a central bore 48, which discharges at the end 50 of the extension 46. The threaded plug 44 has an extension 52, which has an end tang 54 and supports a closing spring 56, which passes a piston-like closing member 60 against the end 50 of the hollow screw 42.
A first transverse bore 62 leads out from the longitudinal bore 40; this transverse bore 62 has a rectangular cross section, and its wall segment 63 on the inflow side is offset by the dimension a from the end 50 of the hollow screw 42. The transverse bore 62 leads into a longitudinal groove 64 on the jacket periphery of the filter body 30, which when viewed in the direction of fuel flow has a V-shaped cross section of continuously descreasing size and terminates at both ends prior to the end faces of the filter body 30. The first flank 66 (FIG. 3) of the longitudinal groove 64 is located in a plane 68, which extends at a distance b from a plane 72 including the longitudinal axis 70 of the filter body 30. The other flank 74 of the longitudinal groove 64 is located upright on the flank 66 and extends at an angle c (FIG. 2) relative to the longitudinal axis 70 of the filter body 30. As a result of this cross-sectional embodiment and disposition, the decreasing depth of the longitudinal groove 64 is attained automatically during the milling process.
A second transverse bore 76 having a circular cross section leads out from the longitudinal bore 40 in the vicinity of the end tang 54, and discharges into a longitudinal groove 78 on the jacket periphery of the filter body 30. The longitudinal groove 78 is embodied in cross section as a mirror image of the longitudinal groove 64 and, like it, is disposed at an angle c with respect to the longitudinal axis 70. The longitudinal groove 78 is located, however, such that it pierces the collar 34 on the outflow side and discharges at the annular end face 80 defining this collar 34. Two further longitudinal grooves 82, 84 are disposed in the filter body 30, being embodied and disposed like the longitudinal groove 78 and forming respective angles of 120° both between each other and with the longitudinal groove 78. Each longitudinal groove 78, 82 and 84 forms a peripheral recess 86 in the collar 34, by way of which recess the annular chamber 38 communicates with the ongoing bore segments 22, 24, 25 of the fuel inflow conduit.
The closing member 60, together with the end face 50 and the edge formed at the point where the transverse bore 62 discharges into the longitudinal bore 40, forms a check valve, shown in FIG. 4 and identified there as a unit by reference numeral 90. This check valve 90 is located in the line conection 48, 40, 62, 64 leading into the annular chamber 38 on the inflow side. From there, the fuel travels via the longitudinal grooves 78, 82, 84 and the three peripheral recesses 86 in the collar 34 into the continuing fuel conduit. The fuel is deflected multiple times thereby and forced to flow through narrow gaps, as a result of which the desired filtering effect takes place.
The fuel pressure, which at the beginning of an injection event is increasing, displaces the closing member 60 away from the end face 50 counter to the force of the closing spring 56, until the closing member 60 opens the transverse bore 62 and the fuel can pass over to the gaps and conduits continuing on from there. The fuel volume positively displaced by the closing member during this process can pass over via the transverse bore 76 and the longitudinal groove 78 into the fuel conduit continuing from there. At the end of the injection event, the closing spring 56 rapidly returns the closing member 60 back to the end face 50, thereby closing the transverse bore 62 and causing the reaspiration via the transverse bore 76 of a certain volume of fuel into the space between the closing member 60 and the threaded plug 44. The distance a is dimensioned such that the reaspirated fuel volume approximately corresponds to the positively displaced volume of the injection valve 17.
Thus, as the closing member 60 moves across transverse bore 62 to close bore 48 further inflow of fuel toward the injection valve is prevented at such time that the transverse bore 62 is closed. As the closing member 60 moves the distance "a" from the transverse bore 62, fuel under pressure between the injection valve 17 and the second transverse bore 76 enters the longitudinal bore 40 via the second transverse bore 76 to fill the space in bore 40 due to movement of closing member 60, as the closing member moves the distance a. Since no fuel is added from the inlet to the injection valve via transverse bore 62, the fuel entering bore 40 relieves the fuel pressure on the injection valve 17 so that the injection valve closes. The volume of fuel that replaces the area in bore 40 due to movement of closing member 60 and the area of the channel upstream of injection valve 17 due to a closing movement of the injection valve relieves the pressure on the injection valve so that the injection valve will remain closed. Therefore, the closing movement of closing member 60 functions as a relief valve to relieve the fuel pressure on the injection valve thereby preventing after-injections.
The foregoing relates to a preferred exemplary embodiment of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims. | A fuel injection nozzle for internal combustion engines having a filter body inserted into the fuel inflow conduit, an injection valve and a check valve, which maintains a static pressure in the injection nozzle and can also perform a relief function for the prevention of after-injections. The check valve is integrated into the filter body thereby simplifying the final assembly of the injection nozzle. The filter body is advantageously embodied as a rod-type filter, which by the appropriate shaping of its jacket periphery forms gap-like spaces between itself and the surrounding wall of the nozzle holder through which spaces the fuel must pass such that it is deflected multiple times. | 5 |
BACKGROUND OF THE INVENTION
[0001] In elegant and upscale dining, it is common to serve wine tableside. It is well known that red wine and white wine are to be served at different temperatures. However, their optimum storage temperature is the same (53-57° F.). Stored wine is defined as, the place wine is kept when one is riot drinking it, be it for a day, a week, or a year, etc. Although the temperature at which wine is stored at is important, it's just as important to take note of the temperature at which wine is served.
[0002] Because of the difference in storage temperatures and service temperatures for red wine and white wine, users who use a single temperature wine refrigerator, are often required to place the white wine into a refrigerator for a half an hour prior to service and the red wine must be taken out of storage a half an hour prior to service (this allows time for white wine to chill and red wine to increase from the storage temperature).
[0003] Yet if one does not use this kind of storing method, but instead the wine is kept at room temperature or in a conventional refrigerator (which can be as cold as 40° F.). The opposite steps would be taken. Put the red wine in the refrigerator for a half an hour and take the white wine out of the refrigerator for a half an hour (this allows for the white wine to increase from the refrigerator temperature and the red wine to decrease from the room temperature).
[0004] Ideally, white wine should be served between refrigerator temperature (40° F.) and storage temperature (55° F.) and red wine should be served somewhere between storage temperature (55° F.) and room temperature of about 70° F. While, red wine and white wine both have different ideal serving temperature, they both have the same ideal storage temperature (53-57° F.); however, they are not always stored at the same temperature or even at their ideal storage temperature.
[0005] As can be seen in a case, whereby a user would like to be able to take wine directly from storage and immediately serve it.
[0006] In order for red wine and white wine to be immediately servable, at its appropriate service temperatures, when they are taken directly from storage. Both wines will have had to have been stored previously in a two temperature wine refrigerator or in two different single temperature wine refrigerators (each one set at different but appropriate temperatures). Here the white wine is kept at around 47 degrees and the red wine is kept at around 56 degrees.
[0007] It should be noted, that even though these wines were able to be served immediately after they were taken from their storage. They will still often be kept in different locations, in order to keep their appropriate serving temperatures.
[0008] From these examples, it can be seen, that regardless of the manner in which red wine and white wine are stored (together or in separate locations), when these wines are served, they will often be required to be held in different location, in order to accommodate their different desired serving temperatures. This is why red wine is typically placed on a table and white wine is typically placed in an ice bucket or the other way around (depending on the way the wine had been previously stored).
[0009] The present invention provided, allows for both red wine and white wine, to be able to be stored in any appropriate manner and regardless of the manner at which the user has chosen to store the wine (room temperature, conventional refrigerator, a two temperature wine refrigerator unit or one or two single temperature wine refrigerator units).
[0010] The wine will be able to be served at their appropriate service temperature; while at the same time allowing them to be located in the same location.
[0011] The system and method of the present invention addresses the need and desire to serve white wine and red wine tableside from a single holding vessel.
BRIEF SUMMARY OF THE INVENTION
[0012] The present invention holds the red and white wine into one configuration and in one location. This is done so that when the wine is in served, the configuration will be able to accommodating the necessary service temperatures, for both the red wine and the White wine.
[0013] The present invention allows both red wine and white wine to be stored in each of their usual accustomed environments, whereby they may be both stored together or in different locations. This is possible because the user has the ability to separate the said configuration in to two parts that may be placed in two different locations, to accommodate different storage means.
[0014] However, it should be noted that the present invention is the accommodation of service temperatures for both red and white wine, from within one single configuration, held in one location and that any configuration arranged in such a way to accommodate the service temperatures for both red and white wine, from within one single configuration, held in one location. Will be considered an infringement of the teaching disclosed herein, regardless of the configurations ability or inability to separate in to two parts.
[0015] The present invention is a system of connecting two bottles having:
[0000] a. a first bottle constructed and arranged with a connection means; and
b. a second bottle constructed and arranged with a connection means;
wherein each of said first bottle connection means and said second bottle connection means secure two bottles in a configuration that provides only a single bottle be at least partially placed in ice or ice with water when connected bottles are placed in a tableside bottle serving chiller.
[0016] In a preferred embodiment, the bottles are detachably connected.
[0017] In a preferred embodiment, the system connecting means is a male-female snap fit configuration. Alternatively, either or both of said first bottle connection means and said second bottle connection means is a plurality of spring-loaded locking pins.
[0018] In one embodiment, one of either said first bottle connection means and said second bottle connection means is a connecting collar.
[0019] In yet another embodiment, each of said first bottle connection means and said second bottle connection means are spring loaded locking pins and each bottle is joined by interaction with a connecting collar.
[0020] Said first bottle connection means and said second bottle connection means, in one embodiment, are bottle sleeves constructed and arranged with one open end and one closed end, at least one spring positioned in an interior base region of said closed end, said spring urges a bottle placed therein towards said open end, said bottle urged against a locking ring placed around a bottleneck.
[0021] Although many of the embodiments depict bottles that are detachably connected one to another, it is also contemplated that permanently connected bottles constructed and arranged to achieve the goals of service at different service temperatures.
[0022] Also contemplated as part of the present invention is a method of serving wine tableside comprising:
[0000] a. selecting a first wine to be served chilled;
b. selecting a second wine to be served at under room temperature;
c. providing a system according to claim 1 ;
d. providing a vessel containing ice, cold water, or a combination thereof;
e. connecting each of said first and second bottles, said first wine residing in said first bottle and said second wine residing in said second bottle;
f. placing said first bottle in said vessel;
g. waiting a sufficient time for said first wine in said first bottle to chill;
h. removing said system from said vessel;
i. serving wine selected from said first wine, said second wine, or a combination thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a side view and partial section view of connected bottles in an ice bucket.
[0024] FIG. 2A is a side view of a wine bottle with a male snap fit arrangement formed on the base of the bottle.
[0025] FIG. 2B is a side view of a wine bottle with a female snap fit arrangement formed on the base of the bottle.
[0026] FIG. 3 is a partial sectional side view of locking pins incorporated into the base of each bottle and the bottles secured one to another with a securing ring.
[0027] FIG. 4 is a partial sectional side view of locking pins incorporated into the base of each bottle and separated from one another above and below a securing ring.
[0028] FIG. 5 is a top view of an embodiment having one bottle on a flat platform area of a second bottle.
[0029] FIG. 6 is a side view of an embodiment having one bottle on a flat platform area of a second bottle.
[0030] FIG. 7 is a front view of an embodiment having one bottle on a flat platform area of a second bottle.
[0031] FIG. 8 is a front section view along line A-A of FIG. 5 of an embodiment having one bottle snap fit on a flat platform area of a second bottle.
[0032] FIG. 9 is a side partial section view of an arrangement of two wine bottles each held in a sleeve with a spring urging each bottle towards a locking ring.
[0033] FIG. 10 is a partial side view from FIG. 9 showing the securing ring and locking screw.
[0034] FIG. 11 is a section partial side view of separated two bottles, with the first bottle having a receiving ring incorporated into the base of the bottle and the second bottle having locking pins incorporated into the base of the bottle.
[0035] FIG. 12 is a section partial side view of connected bottles from FIG. 11 .
[0036] FIG. 13 is a section partial side view of connected bottles from FIG. 1 .
[0037] FIG. 14 is a section view along line C-C from FIG. 1 .
[0038] FIG. 15 is a partial section side view of a first bottle nesting on a second bottle.
[0039] FIG. 15A is a partial section side view of the second bottle from FIG. 15 .
[0040] FIG. 15B is a partial section side view of the first bottle from FIG. 15 .
[0041] FIG. 16 is a partial section side view of two connected bottles from FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] The present invention may be accomplished in any of the varied embodiments set forth herein. As shown in FIGS. 1 , 2 A, and 2 B, a first bottle 18 has a basic constructs and arranged with a snap fit female connector 20 . Snap fit female connector 20 is complementary with male snap fit connector 14 that is constructed and arranged on a base of second bottle 12 .
[0043] Although, FIG. 1 , depicts a single in embodiments where first bottle 18 is positioned vertically above second bottle 12 in a vessel 24 containing ice 26 , it is contemplated that any of the end to end bottle arrangements may be similarly utilized.
[0044] Indeed embodiments depicted in FIGS. 3 and 4 , each of a first bottle 30 and the second bottle 44 are constructed and arranged with interlocking spring-loaded pins 32 incorporated into the base of each respective first bottle 30 and second bottle 44 . Each pin 32 is placed in cavity 46 . Cavity 46 is defined by a rear wall 46 a , a circumferential side wall 46 b and front wall 46 c . Pin 32 is urged outward by spring 34 placed within cavity 46 .
[0045] First bottle 30 and second bottle 44 are secured at each base by placing each respective bottle 30 and bottle 44 into cavity 42 of connecting collar 40 . Each pin 32 will recede under pressure during insertion a bottle into connecting collar 40 . When pin 32 is aligned with collar orifice 38 , and 32 is urged outward through collar orifice 38 by spring 34 .
[0046] In the embodiment depicted in FIGS. 5-8 , a base bottle 50 is constructed and arranged to secure a nesting model 52 thereupon. Base bottle 50 has nesting plaque 458 constructed and arranged with male interconnect 54 that interacts with female interconnect 56 . Female interconnect 56 is formed in the base of nesting bottle 52 .
[0047] In the embodiment of FIGS. 9-10 , a vertical holder 98 has a first cavity 74 constructed and arranged to hold first bottle 60 . Vertical holder 98 has a second cavity 90 constructed and arranged to hold second bottle 76 . First bottle 60 is secured into position with a ring and 64 that encircles bottleneck 62 . Securing rod 66 is operatively connected to ring 64 and extends along the side of vertical holder 98 . Securing rod 66 is fixed into position and released as desired when wing nut 70 is either tightened or loosened about screw 70 .
[0048] The securing arrangement is similar for second bottle 76 . Second bottle 76 is secured into position with a ring 80 that encircles bottleneck 78 . Securing rod 82 is operatively connected to ring 80 and extends along the side of vertical holder 98 . Securing rod 82 is fixed into position and released as desired when wing nut 86 is either tightened or loosened about screw 84 .
[0049] In the embodiment of FIGS. 11 and 12 , first bottle 100 is constructed and arranged with receiving collar 102 that encompasses a receiving cavity 104 . Second bottle 110 has incorporated therein pin 114 , positioned within cavity 120 Cavity 120 is formed of rear wall 120 a , circumferential side wall 120 b , and front wall 120 c . Each pin 114 is urged outward by spring 118 that is placed within cavity 120 .
[0050] As depicted by FIGS. 11-12 , each pin 114 , is urged centrally inward when second bottle 110 is placed into receiving cavity 100 for a first bottle 100 . When pin 114 is aligned with orifice 106 , spring 118 urges pin 114 out word creating the desired interlocking relationship.
[0051] In the embodiment of FIGS. 15 , 15 A, and 15 B, first bottle 130 is constructed and arranged with an interior cavity 132 that nests on bottleneck 138 of second bottle 136 . A snap fit arrangement between male snap fit member 140 and female snap fit member 134 is accomplished when bottleneck 138 is placed fully inside cavity 132 .
[0052] While the invention has been described in its preferred form or embodiment with some degree of particularity, it is understood that this description has been given only by way of example and that numerous changes in the details of construction, fabrication, and use, including the combination and arrangement of parts, may be made without departing from the spirit and scope of the invention. | A system and method that configures a connecting relationship between two wine bottles (or one wine bottle with two wine compartments) such that wine in one bottle/compartment may be served chilled and wine in a second bottle/compartment may be served at a higher temperature than the chilled bottle, while both wines are presented tableside from a single holding vessel. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to improvements made to remote manipulation apparatuses of the "master-slave" type which are intended to allow the remote manipulation of any object by a direct mechanical transmission.
An apparatus of this kind allows an operator, actuating a "master" device lying in a control space, to manipulate objects using the "slave" device lying in a distance and inaccessible work space. This apparatus may be arranged in such a way that it modifies the amplitude of the movements made by the operator, for example to reduce it, this then making it possible to operate in a small work space homothetic with the control space.
The known remote manipulation apparatuses are generally made from articulated mechanical structures of the "series" type: they therefore have their drawbacks of heaviness and bulkiness.
BRIEF SUMMARY OF THE INVENTION
The object of the present invention is essentially to propose an improved remote manipulation apparatus which enjoys the advantages of an appreciable reduction in weight and of bulk as exhibited by articulated structures of the parallel type, and more particularly by those described in document FR-A-2 672 836 in the name of the Applicant. Furthermore and above all, the object of the invention is to allow the numerous types of mobility of the articulations disclosed in the aforementioned document to be put to good use in order to achieve remote manipulation devices with six degrees of freedom which offer optimum flexibility for use.
To this end, a remote manipulation apparatus of the "master-slave" type with six degrees of freedom, three in rotation and three in translation, designed in accordance with the invention, is essentially characterized in that it comprises:
an articulated structure in the form of a deformable parallelogram, comprising two parallel arms each joined, on the one hand, to a crossmember by an articulation with one degree of freedom in rotation about an axis perpendicular to the plane of the parallelogram and, on the other hand, to a structure by an articulation with two degrees of freedom in rotation about two axes, the first axis being perpendicular to the plane of the parallelogram and the second axis being supported by the fourth side of the parallelogram, the four articulations lying at the vertices of the parallelogram, the two arms extending beyond their respective articulation to the structure;
two articulation devices with parallel structure, namely a "master" device and a "slave" device, these devices being arranged respectively at the free end of each arm, each device comprising:
a base supported by the free end of the corresponding arm,
a member which can move relative to the base, forming either the control member in the "master" device, or the controlled member in the "slave" device, the moving member being articulated at its center, with three degrees of freedom in rotation, to a support mounted on the base with the possibility of axial displacement parallel to the axis of the arm, by virtue of which arrangement the moving member has a degree of freedom in axial translation relative to said arm,
four actuator devices approximately parallel to the axis of the arm, inserted between the base and the moving member and surrounding the support, each actuator device comprising
a linkage approximately parallel to the axis of the arm and supported by the base so as to be capable of sliding therein parallel to the axis of the arm,
and a connecting piece of fixed length connected with articulations in rotation to the end of the linkage and to the moving member, the respective positions of the linkages on the base and of the articulations of the connecting pieces on the moving element being such that the connecting pieces are capable of creating moments about three axes of rotation on the moving member, giving it three degrees of freedom in rotation with respect to the corresponding arm,
and five devices for the two-way transmission of linear movement which are inserted
in the case of four of them, between the four actuator devices of the "master" device and the four corresponding actuator devices of the "slave" device,
and, in the case of the fifth one, between the respective supports of the moving control member of the "master" device and of the moving controlled member of the "slave" device,
these two-way transmission devices being arranged in such a way that the linear displacement of one actuator device or of the support of the moving control member of the "master" device is transmitted in the form of a linear displacement in the same sense of the corresponding actuator device or of the support of the moving controlled member of the "slave" device.
An articulation device for the parallel structure like the aforementioned one is already known from the document cited earlier--FR-A-2 672 836 (see claim 5 and FIG. 1 of said document), while the design of a "master-slave" apparatus using two such articulation devices is also mentioned (claim 12 and FIG. 10) without practical embodiments actually having been put forward. The abovementioned provisions for an apparatus in accordance with the invention characterize a novel technical solution and form the basis of a functionally effective apparatus which has six degrees of freedom.
It may also be noted that the device of the invention combines a mechanical structure with two degrees of freedom, forming a tool support, in the form of a parallelogram, and two hand grips of parallel structure derived from the structure described in the document FR 2 672 836. The improvement made to the hand grip consists in employing an actuator dealing exclusively with the degree of freedom in translation, which leads to a master-slave structure with four degrees of freedom and redundancy of means in rotation. A device of this kind offers capabilities for displacement which cannot be obtained using devices of the prior art.
Advantageously, each movement transmission device comprises a flexible transmitter member designed to transmit both pulling forces and thrusting forces, each transmission device comprising a flexible cable enclosed, with the possibility of free longitudinal sliding, in a sheath, each end of which is anchored to the base of an arm; an inverter device designed so that the two ends of the transmitter member, which ends are directed parallel to the axis of the arms, on the bases, will have displacements in the same sense is functionally associated with each movement transmission device thus constructed. Use of the technical solution just proposed makes it possible to establish a flexible and wire-like link between the "master" device and the "slave" device, which leads to an apparatus which is simple to produce and has a small bulk, which relies upon crude but effective and therefore inexpensive members. In particular, it is thus possible to produce the two arms in the form of tubes, these arms containing the respective ends of the aforementioned two-way transmission devices.
Furthermore, it is possible, and advantageous in certain applications, for the two arms of the articulated structure in the form of a deformable parallelogram to have, beyond their articulation with the structure, different lengths, the amplitude of the displacement transmitted by the two-way transmission device inserted between the respective supports of the moving control and controlled members being modified in the same ratio as the ratio of the lengths of the two arms; thanks to this arrangement the extent of the field of operation of the remote manipulation apparatus is transformed in the ratio of the lengths of the arms; in this case it is possible, in particular, to contrive for the length of the arm of the "slave" articulation device to be shorter than the length of the arm of the "master" articulation device, thanks to which arrangement the movements of the "master" articulation device are demultiplied with a reduction ratio that is equal to the ratio of the lengths of the arms with respect to the corresponding movements performed, under its control, by the "slave" articulation device; it is then desirable for the remote manipulation apparatus additionally to comprise, associated with the "slave" articulation device, a viewing device, especially a stereoscopic viewing device, arranged in such a way that it provides an image of the field of operation of the "slave" articulation device with a magnification that is the inverse of the aforementioned reduction ratio, so as to form a complete apparatus which is very easy for the operator to use.
It may be noted at this point that the apparatus of the invention has a wire-like structure which lends itself well to use in the field of surgery or in any field which requires intervention in a restricted work space, such as microelectronics for example. However, the benefit of the apparatus of the invention is not simply restricted to these applications but covers all the conventional fields of remote manipulation.
It will also be noted that with the exception of the accessory special-purpose sensors which are associated with the anticipated application of the apparatus (generally a camera), the apparatus of the invention, by feeding back forces both in terms of pulling and in terms of compression and rotation, requires no sensors, no electronics and therefore no computer systems to control it. A direct consequence of this novel feature is of course that it appreciably reduces the cost of manufacture.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood from reading the detailed description which follows of a number of preferred embodiments which are given merely by way of nonlimiting examples. In this description, reference is made to the appended drawings in which:
FIG. 1 is a highly diagrammatic view of a remote manipulation apparatus of the "master-slave" type arranged in accordance with the invention;
FIG. 2 is a view, on a larger scale and in greater detail, of the end of one of the arms of the apparatus of FIG. 1;
FIGS. 3 and 4 are views, on a larger scale, of each of two alternative embodiments of articulations of the apparatus of FIG. 1;
FIG. 5 is a view, on a larger scale, of other articulations of the apparatus of FIG. 1;
FIGS. 6 and 7 are views, on a larger scale and in greater detail, of each of two alternative embodiments of an inverter device of the apparatus of FIG. 1; and
FIG. 8 is a highly diagrammatic view of an alternative form of the apparatus of FIG. 1.
FIG. 9 shows an enlargement of FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
Depicted overall and diagrammatically in FIG. 1 is a remote manipulation apparatus of the "master-slave" type arranged in accordance with the invention.
It comprises an articulated structure 1 in the form of a deformable parallelogram, comprising two parallel arms 2, a crossmember 3 and a structure 4. The crossmember 3 is connected, with free rotation, by articulations 5 with one degree of freedom, to the ends of the arms 2; the structure 4 is connected with free rotation, by articulations 6 with two degrees of freedom, to intermediate points A and A' respectively on the arms 2; the arms 2 thus extend beyond the articulations 6.
The articulations 6 have the two necessary degrees of rotation about two coplanar and mutually perpendicular axes at the points A and A' respectively. FIG. 3 shows a first possible arrangement, of the Cardan type, in which the arm 2 can pivot about the axis v, and the arm 2 and the axis v can pivot about the axis u supported by the fourth side AA' of the parallelogram; the axis u may be a shaft pivoting at its end on the fixed structure 4.
Use may also be made of a spherical articulation 6, supported by the structure 4, as shown in FIG. 4.
The two articulations 5 may be arranged as depicted in FIG. 5, to provide just one degree of freedom in rotation about an axis w. Of course, the axes w of the articulations 5 and the axes v of the articulations 6 are mutually parallel and are perpendicular to the plane of the parallelogram.
Placed respectively at the respective free ends of the two arms 2 are two articulation devices with parallel structure--a "master" device 8, and a "slave" device 9. The two devices--the "master" device 8 and the "slave" device 9--are constructed identically and are arranged, in a way known per se, in accordance with the teachings of document FR-A-2 672 836 to correspond to the embodiment of FIG. 10 and claim 5. This being the case, each device 8, 9 comprises, as can be seen more particularly in FIG. 2, the following elements:
A base 10 which consists of the free end of the arm 2; this may, as shown in FIG. 2, be an end fitting attached and fixed to or into the end of the arm 2.
A member 11 (comprised of a plate 11a and protrusions 11b) that can move relative to the base 10, constituting the actual control member of the "master" device 8 and the controlled member (especially tool-holding gripper) of the "slave" device 9. This moving member 11 is supported centrally, with an articulation 12 that has three degrees of freedom in rotation, on a support 13 mounted on the base 10 with the possibility of axial displacement relative to said arm. In this instance the support 13 consists of a rod approximately coaxial with the arm 2 and sliding axially with respect thereto. In the instance depicted, the base 10 supports the rod 13 so that it is free to slide. It will be noted that it would have been possible also for the support 13 to have been secured to the base 10, which would have been mounted so that it could slide on or in the arm 2. Thanks to this arrangement, the moving member 11 has a degree of freedom in axial translation.
Four actuator devices 14 approximately parallel to the axis of the arm, inserted between the free end of the arm and the moving member 11. These four actuator devices 14 are distributed around the support 13 (only two actuators have been depicted in FIG. 2). Each actuator device 14 comprises:
a linkage 15 approximately parallel to the axis of the arm 2 and supported by the base 10 in which it slides freely,
and a connecting piece 16 of fixed length connected with articulations in rotation to the end of the linkage 15 and to the moving member 11,
the respective positions of the linkages 15 on the base 10 and of the articulations of the connecting pieces 16 on the moving member 11 being such that the connecting pieces 16 are capable of creating moments about three axes of rotation on the moving member 11, giving it three degrees of freedom in rotation relative to the arm 2.
It will be noted at this point that the connections 17 between the connecting pieces 16 and the respective linkages 15 are connections which are articulated in space, such as balljoints or Cardan joints, and that the connections 18 between the connecting pieces 16 and the moving member 11 are connections which are articulated in space such as balljoints.
And finally, five devices 19 for the two-way transmission of linear movement (that is to say devices capable of transmitting a linear movement selectively in the two possible senses in a given direction) which are inserted
in the case of four of them, between the four actuator devices 14 of the "master" device 8 and the corresponding four actuator devices 14 of the "slave" device 9,
and, in the case of the fifth, between the respective supports 13 of the moving control member of the "master" device 8 and of the moving controlled member of the "slave" device 9.
An economical and simple way of producing the force-transmission devices consists in using a connection using piano wire or a similar cable 20 (see FIGS. 6 and 7) contained in a flexible sheath 21 anchored at its ends and which is capable of transmitting forces in both directions. Recourse could, of course, be had to other known means, such as controls with balls.
In order to maintain the sense of the transmission of the displacement from the moving control member to the moving controlled member, an inverter device 22, arranged in such a way that the two ends of the transmitter member, in this case the cable 20, have displacements in the same sense at the respective ends of the arms 2, is associated with each transmission device 19.
The inverter device 22 may be produced as shown in FIG. 6. The transmission device 19 is split into two parts 19a and 19b arranged more or less end to end; the ends of the half cables 20 are connected to or shaped in the form of respective racks 23 arranged face to face and meshing with an inserted cog wheel 24 mounted to rotate freely on the casing 25 of the device.
The inverter device can also be constructed as shown in FIG. 7. The two parts 19a and 19b of the transmission device 19 are joined together side by side, as a bundle, and are secured by any known means, by soldering or alternatively, as depicted, by being crimped into a sleeve 26, which is installed with free axial sliding in a guide bushing consisting of a casing 27 and, preferably, with the insertion of ball guides 28.
It will be noted that the arms 2 may advantageously be produced in the form of tubes, not only so that they will be non-deformable for a minimum weight, but also to serve as a guide for the five transmission devices 19, in the end regions thereof.
Furthermore, it will also be noted that the remote manipulation device depicted in FIG. 1 with arms 2 of the same length gives the control member and the controlled member the same amplitudes of operation. It is envisageable for the two arms 2 to be given different lengths (this referring to the length of each arm between its articulation 6 and its free end) and for use to be made of an inverter device 22 in which the displacement-transmission ratio is other than unity, in the transmission device inserted between the supports 13 of the moving members 11 of each arm 2; this then gives different amplitudes of linear displacement for the control member and the controlled member, the angles of rotation being kept the same. In particular, as shown in FIG. 8, the arm 2 of the "master" device 8 may have a length k times greater than that of the arm 2 of the "slave" device 9: the linear displacements of the control member of the "master" device 8 are then transmitted to the controlled member of the "slave" device 9 with a demultiplication by a ratio k. Depending on the envisaged application, this remote manipulation device could be coupled to a viewing device, especially a stereoscopic viewing device which reproduces, within the operator's eyepiece, a three-dimensional virtual image, enlarged in the homothetic ratio k so that the operator has the feeling that he is working directly on this virtual image. Furthermore, combining two complete remote manipulation devices may allow an operator to work with both hands.
As goes without saying and as is already obvious from the foregoing, the invention is not in any way restricted to those of its applications and embodiments which have been more specifically envisaged; to the contrary, it encompasses all alternative forms thereof. | A "master-slave" remote manipulation apparatus having six degrees of freedom. The apparatus includes a flexible parallelogram with two parallel arms hinged to a cross member with one degree of rotational freedom and to a frame with two degrees of rotational freedom; two parallel-hinged "master" and "slave" devices at the end of each respective arm; and five two-way linear motion transmitting devices between the "master" and "slave" devices. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is the U.S. National Phase of International Application No. PCT/US2008/003072, filed Mar. 7, 2008, entitled “BORON-DOPED SINGLE-WALLED NANOTUBES (SWCNT)”, which claims the benefit of U.S. Provisional Patent Application No. 60/893,513, filed Mar. 7, 2007, which applications are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention generally relates to methods and apparatus for the synthesis or preparation of boron-doped single-walled carbon nanotubes (B-SWCNTs).
BACKGROUND OF THE INVENTION
[0003] This invention relates to nano-materials and methods and apparatuses for forming nano-materials and, more particularly, to boron-doped carbon nanotubes and a method and an apparatus for forming the same.
[0004] Carbon nanotubes (CNT) possess unique properties such as small size, considerable stiffness, and electrical conductivity, which makes them suitable for a wide range of applications, including use as nanocomposites, molecular electronics, and field emission displays. Carbon nanotubes may be either multi-walled (MWCNTs) or single-walled (SWCNTs), and have diameters on the nanometer scale.
[0005] A single-walled carbon nanotube (SWCNT) consists of a single atomic layer of carbon wrapped into a seamless long cylinder. They are typically a few nanometers in diameter and many microns long. They often appear as bundles of tubes. Depending on the values of the so-called “chirality integers” (n,m) that define the way the carbon hexagons spiral up the tube axis, these atomic filaments can be shown to be either semiconducting or metallic.
[0006] In many large batch processes that produce carbon nanotubes, a mixture of nanotubes with various (n,m) and diameters is obtained. Furthermore, it is commonly believed that these various (n,m) are present in a statistical mixture of about ⅓ metallic and ⅔ semiconducting tubes.
[0007] It is known from semiconductor physics that chemical doping (i.e., the addition of impurity atoms to the semiconductor) can lead to a substantial increase in the free carrier concentration and therefore to an enhancement in the electrical and thermal conductivity.
[0008] In applications of nanotubes that require highly conducting filaments, it is either desirable to produce nanotubes powders that exhibit an increase in the fraction of metallic tubes in the material, or one can endeavor to increase the conductivity of the semiconducting fraction. This invention is about the latter, i.e., enhancing the conductivity of the semiconducting fraction of the tubes via chemical doping, and doing so during the synthesis of the nanotubes (in situ). The present invention makes use of the concept of chemical doping to SWCNT tubes during their production by the “Arc discharge” method.
BRIEF SUMMARY OF THE INVENTION
[0009] Two approaches to doping and enhanced electrical and thermal conductivity in SWCNT are possible: (1) via several chemical approaches, attach a molecule or atom to the outside or inside of the tube wall (attachment doping). These attachments can be carried out during the synthesis of the nanotube, or afterwards. For example, a potassium atom, when fixed on the side of the nanotube wall would rather be a charged positive ion (K+) than a neutral atom (K). Consequently, the electron given up by the neutral atom in producing the ion is transferred to lower lying states in the conduction band of the nanotube wall. This transfer results in an enhanced electron population in the tube wall and an increase in the free carrier (electron) concentration. A second route to enhanced free carrier concentration in the SWCNT wall is also possible. In (2), an element (e.g., boron or B) is substituted for some of the carbon atoms in the tube wall. This second form of chemical doping (called substitutional doping) also leads to an enhanced free carrier concentration and higher electrical conductivity.
[0010] The advantage of “substitutional” doping over “attachment” doping is in the stability of the material. Unfortunately, not many atom types can be substituted for carbon in the nanotube wall. From work in graphite, it is known that boron is the only atom that is small enough to be substituted for a C-atom in an sp2-bonded carbon layer in graphite (graphene layer) and have the layer structure retain the characteristic in-plane honeycomb structure. One therefore expects B-substitution to be possible in the wall of carbon nanotubes with a minimal distortion of neighboring carbon hexagons. Therefore, a semiconducting tube doped with boron, i.e., a B-doped SWCNT (i.e., B-SWCNT) is anticipated and this doped tube would be expected to exhibit more free carries than in the undoped state and therefore be a significantly better electrical and thermal conductor than a pristine (undoped) semiconducting tube with the same chiral indices (n,m).
[0011] This prediction indicates that B-SWCNTs should be the desirable form of nanotube in applications where a highly electrical conducting composite media are required via the mixing of nanotubes and say a polymer host, such as for the case of low mass density electromagnetic interference (EMI) shielding and for a transparent conductive films, such as required in touch screen technology. When polymer-nanotube composites are mentioned for high strength EMI applications, one should consider B-doped SWCNTs as the most appropriate way to add mechanical strength and raise the conductivity in the nanotube composite.
[0012] Carbon nanotubes can be grown in an arc discharge between carbon electrodes in the presence of He and other gases. One of the electrodes should contain a catalyst in the form of small particles well dispersed amongst the carbon. The ion current between the electrodes vaporizes the material in the consumable catalyzed carbon (CC) electrode and presumably small metal particles form in the plasma discharge which can seed the growth of either individual SWCNT or bundles of SWCNTs; the tails of these filaments are attached to the metal particles during growth.
[0013] Surprisingly, the present invention provides for materials and methods of introducing boron into the vapor phase in the discharge along with the carbon vapor, to form boron-doped, single-walled carbon nanotubes (B-SWCNTs). There have been claims that B-doping has occurred during synthesis, but there has not been substantial proof provided that the boron is indeed substituted in the tube wall. Therefore, the present invention provides for the two-fold discovery: (1) in situ boron-doping has not been demonstrated via demonstration of p-type conduction of the nanotubes and (2) the present invention is able to introduce B-dopant in a large production scale Arc Discharge process.
[0014] The electrodes for the arc discharge method are prepared by incorporating ˜1-10 atomic % boron as boron carbide (B 4 C) or some suitable other form, e.g., boron oxide (B 2 O 3 ), boron nitride (BN) and boron phosphide (BP), with the main ingredients, e.g., carbon and binder. The electrodes are hot pressed at 1-4 tons for 2-10 h at 200 C and then annealed at 1000 C in nitrogen gas (N 2 ) for 5-10 h.
[0015] In one embodiment of the present invention, the electrodes are introduced into the Arc Discharge (AD) chamber and a gap of 1-4 mm is maintained between the electrodes while passing currents of ˜100-400 A between the electrodes. The discharge vaporizes the carbon and produces a SWCNT soot.
[0016] In one embodiment, a catalyst is incorporated into one or more electrodes. The catalyst is preferably one or more Group VI or VIII transition metals. In another embodiment, boron and nickel are incorporated in one or more carbon electrodes. The electrode may also incorporate one or more binders. In another embodiment, the catalyst is Fe, Co or Ni and/or their alloys. In another embodiment, a third element, e.g., Mo or a rare earth, e.g., Y is added. In another embodiment, boron and nickel-yttrium are incorporated in one or more carbon electrodes.
[0017] In one embodiment, the methods of the present invention produce 100 grams SWCNT soot in ˜2 hours.
[0018] In another embodiment, the SWCNTs are processed by post synthesis purification by selective oxidation and acid reflux.
[0019] In the present invention, boron is substituted for carbon in the sp2 framework of SWCNTs. The B-doped SWCNT can be produced in an industrial scale with controlled boron concentration.
[0020] In one embodiment, boron-doped nanotube films can be deposited on a wide range of substrates with desired thickness. Such B-SWCNT films have a much lower sheet resistance than that of similar thickness SWCNT films.
[0021] In another embodiment, a method for producing tubular carbon molecules of about 5 to 500 nm in length is also disclosed. The method includes the steps of forming single-wall nanotube containing-material to form a mixture of tubular carbon molecules having lengths in the range of 5-500 nm and isolating a fraction of the molecules having substantially equal lengths.
[0022] In one embodiment, the nanotubes disclosed are used, singularly or in multiples, in power transmission cables, in solar cells, in batteries, as antennas, as molecular electronics, as probes and manipulators, and in composites.
[0023] Accordingly, it is an object of this invention to provide a high yield, single step method for producing large quantities of continuous macroscopic carbon fiber from single-wall carbon nanotubes using inexpensive carbon feedstocks wherein the carbon nanotubes are produced by in situ boron substitutional doping.
[0024] It is another object of this invention to provide macroscopic carbon fiber made by such a method.
[0025] The invention provides nanotube films and articles and methods of making the same. Under one aspect of the invention, a conductive article includes an aggregate of nanotube segments in which the nanotube segments contact other nanotube segments to define a plurality of conductive pathways along the article.
[0026] Under other aspects of the invention, the nanotube segments may be single walled carbon nanotubes, or multi-walled carbon nanotubes. The various segments may have different lengths and may include segments having a length shorter than the length of the article.
[0027] The articles so formed may be disposed on substrates, and may form an electrical network of nanotubes within the article itself. Under other aspects of the invention, conductive articles may be made on a substrate by forming a nanotube fabric on the substrate, and defining a pattern within the fabric in which the pattern corresponds to the conductive article.
[0028] Under other aspects of the invention, the nanotube fabric is formed by depositing a solution of suspended nanotubes on a substrate. The deposited solution may be spun to create a spin-coating of the solution. Under other aspects of the invention, the solution may be deposited by dipping the substrate into the solution. Under other aspects of the invention, the nanotube fabric is formed by spraying an aerosol having nanotubes onto a surface of the substrate. The invention provides a method of making a film of conductive nanotubes.
[0029] It is also an object of this invention to provide a molecular array of purified boron-doped single-wall carbon nanotubes for use as a template in continuous growing of macroscopic carbon fiber.
[0030] It is also an object of the present invention to provide a new class of tubular boron-doped carbon molecules, optionally derivatized with one or more functional groups.
[0031] It is also an object of this invention to provide a number of devices employing the carbon fibers, nanotube molecular arrays and tubular carbon molecules of this invention.
[0032] It is an object of this invention to provide composite material containing boron-doped carbon nanotubes.
[0033] It is another object of this invention to provide a composite material that is resistant to delamination.
[0034] In another embodiment, a macroscopic molecular array comprising at least about 10 6 single-wall carbon nanotubes in generally parallel orientation and having substantially similar lengths in the range of from about 5 to about 500 nanometers is disclosed.
[0035] In another embodiment, a composition of matter comprising at least about 80% by weight of single-wall carbon nanotubes is disclosed.
[0036] In still another embodiment, macroscopic carbon fiber comprising at least about 10 6 single-wall carbon nanotubes in generally parallel orientation is disclosed.
[0037] In another embodiment, a composite material containing boron-doped nanotubes is disclosed. This composite material includes a matrix and a carbon nanotube material embedded within the matrix.
[0038] In another embodiment, a method of producing a composite material containing boron-doped carbon nanotube material is disclosed. It includes the steps of preparing an assembly of a fibrous material; adding the carbon nanotube material to the fibrous material; and adding a matrix material precursor to the carbon nanotube material and the fibrous material.
[0039] In another embodiment, a three-dimensional structure of derivatized single-wall nanotube molecules that spontaneously form is disclosed. It includes several component molecule having multiple derivatives brought together to assemble into the three-dimensional structure.
[0040] In another embodiment, a method for forming a macroscopic molecular array of tubular carbon molecules is disclosed. This method includes the steps of providing at least about 10 6 SWCNTs; introducing a linking moiety onto at least one end or side wall of the tubular carbon molecules; providing a substrate coated with a material to which the linking moiety will attach; and contacting the tubular carbon molecules containing a linking moiety with the substrate.
[0041] In a further embodiment, the SWCNTs are of substantially similar length in the range of 50 to 500 nm. In another embodiment, the SWCNTs have a length as long as 5, 10, 15 or 20 microns, or longer depending upon the growth conditions used.
[0042] The above summary of the present invention is not intended to describe each embodiment or every implementation of the present invention. Advantages and attainments, together with a more complete understanding of the invention, will become apparent and appreciated by referring to the following detailed description and claims taken in conjunction with the accompanying drawings.
[0043] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices and materials similar or equivalent to those described herein may be used in the practice or testing of the invention, the preferred methods, devices and materials are now described.
[0044] All publications mentioned herein are incorporated herein by reference for the purpose of describing and disclosing the compositions and methodologies which are described in the publications which might be used in connection with the presently described invention. The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the invention is not entitled to antedate such a disclosure by virtue of prior invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention. In the drawings:
[0046] FIG. 1( a ) depicts a percolating network of SWCNT bundles (schematic). FIG. 1 b . Percolation theory predicts that a sharp threshold for rapid increase in the conductivity will be observed as the density of the tubes per unit area is increased. The data are for SWCNTs dispersed in a polymer from work of P. Eklund and Y Chen et al.
[0047] FIG. 2 shows the results of electron energy loss spectroscopy (EELS) study of a B-doped SWCNT bundle produced in the CarboLex Arc. The material was produced by adding 1 at % B 4 C to the electrode(s). Electron Energy Loss Spectroscopy performed on a spot in the bundle confirms B is present at the sub 1% level. The results are shown: (a) a transmission electron microscopy (TEM) micrograph of Bundle 1A of the boron-doped SWCNTs; (b) a graph of the energy loss of Bundle 1A as determined by electron energy loss spectroscopy (EELS); (c) a transmission electron microscopy (TEM) micrograph of Bundle 2 of the boron-doped SWCNTs; (d) a graph of the energy loss of Bundle 2 as determined by electron energy loss spectroscopy (EELS). In electron energy loss spectroscopy (EELS), a material is exposed to a beam of electrons with a known, narrow range of kinetic energies. Some of the electrons will lose energy by inelastic scattering, which is primarily an interaction of the beam electron with an electron in the sample. This inelastic scattering results in both a loss of energy and a change in momentum.
[0048] FIG. 3 depicts the experimental setup used for the post-synthesis B-doping via exposure to B 2 O 3 and NH 3 after electric arc synthesis of the boron-doped, single-walled carbon nanotubes (B-SWCNTs) useful in one embodiment of the present invention wherein the arc discharge created SWCNTs and boron oxide (B 2 O 3 ) are reacted under ammonia gas pressure of from 0 to ˜200 torr and at a temperature of ˜1150° C. FIG. 1( a ) depicts typical furnace conditions for the B-doping of post arc synthesis SWCNT bundles. A stream of NH 3 is passed over B 2 O 3 /SWCNT mixture and induces the B-doping. FIG. 1( b ) a graph showing the Raman spectra showing changes in the G-band region due to B-doping as Raman shift (cm −1 ) versus the intensity (in arbitrary units). The pressure refers to reaction conditions in FIG. 3 a . The curves (from bottom to top) show the pristine sample, 0 torr, 20 ton and 1000 ton, respectively.
[0049] FIG. 4 is a graphical representation of boron substitution for carbon in the sp2 framework.
[0050] FIG. 5 shows the results of electron energy loss spectroscopy (EELS) study of post synthesis B-doping. Here, the sample was doped after arc synthesis by B 2 O 3 /NH 3 reaction. The results are shown: (a) a transmission electron microscopy (TEM) micrograph of 1% boron-doped SWNTs; (b) a graph of the energy loss as determined by electron energy loss spectroscopy (EELS); (c) a transmission electron microscopy (TEM) micrograph of 3% boron-doped SWNTs; (d) a graph of the energy loss as determined by electron energy loss spectroscopy (EELS).
[0051] FIG. 6 depicts the Raman Spectrum of SWCNTs. FIG. 6( a ) shows the tube wall damage (via the D-band scattering at ˜1350 cm-1) incurred via oxidation in can be annealed away. The band at 1350 cm-1 is the so-called disorder band (or D-band). Purification refers to HNO 3 reflux—this removes some C from the tube walls as CO2. The dangling bonds terminate later with —COOH or —OH. Annealing at 1100 C for 24 h removes these functional groups and restores wall order. In Fig. (b), the D-band must be due to B-doping, not wall disorder, as annealing cannot remove the D-band. The D-band is due to boron in the tube walls. Samples are analyzed using a laser at 514 nm and 0.46 mw power.
[0052] FIG. 7 shows the Raman spectra of a nanotube powder (a) The boron-doped, single-walled carbon nanotubes (B-doped SWNTs) are analyzed using a laser at 514 nm and 0.46 mw power. Each graph represents (from bottom to top) a spectral graph of undoped SWNT, 1% boron-doped SWNT; 2% boron-doped SWNT; and 3% boron-doped SWNT. These % refer to B at % added to the arc electrode. In the analysis, SWNT Raman G-band dominates the spectrum and boron substitution induces “D-band” scattering at 1350 cm −1 and broadens nanotube peaks at low frequency (R-band) and high frequency (G-band).
[0053] FIG. 8 is a graph showing boron-doping induced E 11 S peak shift. FIG. 6( a ) shows the optical density of the boron-doped, SWNTs where X is equal to the at. % of boron in the electrode of the SWNTs. Above 2 wt. %, the E 11 S peak is suppressed due to higher tube wall conductivity. FIG. 6( b ) shows the blue shift of the E 11 S peak with increasing percentages of boron doping. This upshifting of the peak can be interpreted as further direct evidence of B in the tube wall.
[0054] FIG. 9 is graphical depiction of sheet resistance (Rs) measurements wherein sheet resistance is calculated according to the following formula: Rs=exp(−πRA/Rs)+exp(−πRB/Rs)=1.
[0055] FIG. 10 is (a) an optical photograph of a SWNT film (˜3 mm×3 mm) deposited on quartz and (b) the experimental set-up showing the SWNT being deposited onto the substrate mounted on a glass slide. The tubes are dispersed in ethanol and sprayed through a mask with an air brush to produce a uniform film.
[0056] FIG. 11 is a graph showing (a) the percent transmittance (% T) of the SWNT film as a function of the wavelength (nm) and (b) the film (sheet) resistance (Rs) of doped and undoped SWNT as a function of the energy (eV). The graphs represent SWNT RAW, 3 mm×3 mm area, 2 h at 200° C. in N 2 wherein R A =543 Ohms; R B =583 Ohms; and R s =1276 Ohms per square.
[0057] FIG. 12 is a graph showing the sheet resistance (R s ) of doped and undoped SWNT as a function of percent transmittance at 550 nm. The decrease in the sheet resistance is evidence that the B-doping has increased the electrical conductivity of the film, as expected.
[0058] Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings. Alternate embodiments will also be discussed.
DETAILED DESCRIPTION OF THE INVENTION
[0059] Before the present methods and devices are disclosed and described, it is to be understood that this invention is not limited to the particular process steps and materials disclosed herein as such process steps and materials may vary somewhat. It is also to be understood that the terminology used herein is used for the purpose of describing particular embodiments only and is not intended to be limiting since the scope of the present invention will be limited only by the appended claims. It must be noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise.
[0060] The present invention is directed to a novel composite that comprises boron-doped, single walled carbon nanotubes in an inorganic matrix. Because of the highly dispersed nature of the CNTs, these composites are electrically conductive at low levels of CNTs. Such composites can be fabricated in a variety of shaped articles, such as rods, or in the form of thin films on substrates. These composites are useful in various electronic devices, especially nano-sized devices, such as but not limited to chemical or biological sensor, molecular transistor, optoelectronic device, field-emission transistor, artificial actuators, or single-electron device.
[0061] In describing and claiming the present invention, the following terminology will be used in accordance with the definitions set out below.
[0062] The term “CNT” means carbon nanotube; “MWCNT” means multi-walled nanotube; and “SWCNT” means single walled nanotube.
[0063] The term “carbon nanotube” refers to a hollow article composed primarily of carbon atoms. The carbon nanotube can be doped with other elements, e.g., metals. In a preferred embodiment, the metal is attached on the outside of the nanotubes wall. In the present invention, Boron is used to substitute for carbon atoms in the sp2 structure of the wall. The nanotubes typically have a narrow dimension (diameter) of about 1-200 nm and a long length, where the ratio of the long dimension to the narrow dimension, i.e., the aspect ratio, is at least 10. In general, the aspect ratio is between 10 and 100000.
[0064] Carbon nanotubes of the invention are generally about 0.5-2 nm in diameter where the ratio of the length dimension to the diameter, i.e., the aspect ratio, is at least 10. In general, the aspect ratio is between 10 and 100,000. Carbon nanotubes are comprised primarily of carbon atoms, however, they may be doped with other elements, e.g., metals, which reside on the outside of the tube. The carbon-based nanotubes of the invention are single-walled nanotubes (SWCNTs). A MWCNT, for example, includes several concentric nanotubes each having a different diameter. Thus, the smallest diameter tube is encapsulated by a larger diameter tube, which in turn, is encapsulated by another larger diameter nanotube. A SWCNT, on the other hand, includes only one nanotube. CNT's have a variety of conductive properties but are typically classified as metallic or semiconducting depending on their relative conductance. For a review of the electronic properties of CNT's see Avouris et al., Applied Physics of Carbon Nanotubes (2005), 227-251. Editor(s): Rotkin, Slava V.; Subramoney, Shekhar. Publisher: Springer GmbH, Berlin, Germany.
[0065] Carbon nanotubes, and in particular the single-wall carbon nanotubes of this invention, are useful for making electrical connectors in micro devices such as integrated circuits or in semiconductor chips used in computers because of the electrical conductivity and small size of the carbon nanotube. The carbon nanotubes are useful as antennas at optical frequencies, and as probes for scanning probe microscopy such as are used in scanning tunneling microscopes (STM) and atomic force microscopes (AFM). The carbon nanotubes may be used in place of, or in conjunction with, carbon black in tires for motor vehicles. The carbon nanotubes are also useful as supports for catalysts used in industrial and chemical processes such as hydrogenation, reforming and cracking catalysts. They are also useful for EMI and filed emission devices FEDs.
[0066] Ropes of B-doped single-wall carbon nanotubes made by this invention are metallic, i.e., they will conduct electrical charges with a relatively low resistance. Ropes are useful in any application where an electrical conductor is needed, for example as an additive in electrically conductive paints or in polymer coatings or as the probing tip of an STM.
[0067] In defining carbon nanotubes, it is helpful to use a recognized system of nomenclature. In this application, the carbon nanotube nomenclature described by M. S. Dresselhaus, G. Dresselhaus, and P. C. Eklund, Science of Fullerenes and Carbon Nanotubes, Chap. 19, especially pp. 756 760, (1996), published by Academic Press, 525 B Street, Suite 1900, San Diego, Calif. 92101-4495 or 6277 Sea Harbor Drive, Orlando, Fla. 32877 (ISBN 0-12-221820-5), which is hereby incorporated by reference, will be used. The single wall tubular fullerenes are distinguished from each other by double index (n,m) where n and m are integers that describe how to cut a single strip of hexagonal “chicken-wire” graphite so that it makes the tube perfectly when it is wrapped onto the surface of a cylinder and the edges are sealed together. When the two indices are the same, m=n, the resultant tube is the to be of the “arm-chair” (or n,n) type, since when the tube is cut perpendicular to the tube axis, only the sides of the hexagons are exposed and their pattern around the periphery of the tube edge resembles the arm and seat of an arm chair repeated n times. Arm-chair tubes are a preferred form of single-wall carbon nanotubes since they are metallic, and have extremely high electrical and thermal conductivity. In addition, all single-wall nanotubes have extremely high tensile strength.
Arc Discharge Boron Doping
[0068] In a first embodiment of the present invention, a method for forming boron-doped carbon nanotubes comprises the following steps:
a) providing a first and second carbon sources wherein at least one carbon source is a carbon rod (the first, cathode connected rod) that comprises boron; b) connecting a boron-containing carbon rod to a negative terminal (cathode) of the electric arc discharge supply; c) connecting a second rod to a positive terminal (anode) of an electric arc discharge supply; d) placing the first and second rods adjacent to each other in order to create an arc gap; e) putting the rods into an arc discharge reaction chamber, creating a vacuum in the reaction chamber, and introducing a protecting gas (e.g., He) at a predetermined pressure therein; and f) applying a discharge current between the first and second rods whereby boron-doped carbon nanotubes are formed.
[0075] In one embodiment, the second rod is a carbon rod. In another embodiment, the second rod is a substantially pure graphite rod or a boron-containing carbon rod. In another embodiment, the second rod is not consumed in the reaction. In another embodiment, the second rod is a boron-containing carbon rod that is consumed by alternating the current direction of the arc discharge current. In another embodiment, the alternating frequency of the current direction of the arc discharge current is between 1 second and 1 KHz. In another embodiment, the second rod is substantially free of interfering materials.
[0076] In another embodiment, the first and second carbon sources are first and second carbon rods formed by pressing a catalyst powder and high purity graphite particles. In another embodiment, the carbon source further comprises from about 5 to about 50% of a binder. In another embodiment, the binder is Grade GC Dylon paste carbon cement supplied by Dylon, a commercially available binding paste made of graphite, carbon, furfuryl alcohol, and phenolic resin. In another embodiment, the carbon source further comprises from about 10 to about 30% of Grade GC Dylon paste carbon cement. In another embodiment, the carbon source further comprises from about 0.1 to about 10% carbon fibers. In another embodiment, the carbon fibers are in the range of about 0.5 to about 30 microns.
[0077] In another embodiment, the anodes comprise uniformly mixed composite rods made by mixing a paste produced from mixing high-purity metals or metal oxides at the ratios given below with graphite powder and Grade GC Dylon paste carbon cement supplied by Dylon and placing the mixture in a mold and hot pressing at from about 1 to about 4 tons or more of pressure for about 2 to about 10 h at 200 C and then annealing in an inert gas (N 2 ) for about 1-24 hours, preferably 5-10 hours. The rod annealing temperature range may be 400 to 1500 C., most preferably 700 to 1200 C. In one embodiment, the rods are annealed at 1000 C.
[0078] In another embodiment, the mixed composite rods comprise from about 5 to about 50% of the electrode mass.
[0079] The boron-carbon electrodes for the arc discharge method are prepared by incorporating from about 0.1 atomic weight percent (at. wt. %) to about 15 at. wt. % of boron. In another embodiment, the boron-carbon electrodes for the arc discharge method are prepared by incorporating from about 1 at. wt. % to about 10 at. wt. % of boron.
[0080] In one embodiment, the boron is supplied as elemental boron, as boron carbide (B 4 C) or some suitable other form, e.g., boron oxide (B 2 O 3 ), boron nitride (BN) and boron phosphide (BP), along with the main ingredients, e.g., carbon and binder.
[0081] In one embodiment of the present invention, the electrodes are introduced into the Arc Discharge (AD) chamber and a gap of 1-4 mm is maintained between the electrodes while passing currents of ˜100-400 A between the electrodes. The discharge vaporizes the carbon and produces a SWCNT soot.
[0082] In another embodiment, the catalyst powder comprises nickel powder, ytterbia powder, a composite of nickel powder and ytterbia powder, or cobalt powder. In alternative embodiments, other suitable materials such as pure cobalt powder, pure nickel powder or the like can be used as the catalyst and pressed with the graphite particles. In another embodiment, ytterbium metal is used.
[0083] In one embodiment, the protecting gas comprises helium, argon, nitrogen, hydrogen or mixtures thereof. Furthermore, a cooling jacket can be used around the arc discharge reaction chamber to avoid excessive build-up of heat therein.
[0084] In another embodiment, the carbon rods each have a diameter in the range from 2 to 100 millimeters. In another embodiment, the carbon rods each have a diameter in the range from 6 to 50 millimeters.
[0085] In one embodiment, the arc gap is about in the range from about 1 to about 6 mm. In another embodiment, the arc gap is about in the range from about 1 to about 4 mm. In another embodiment, the arc gap is maintained at about 1.5 to 2 millimeters. In another embodiment, the arc gap is maintained at a distance of at least 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2 mm.
[0086] In another embodiment, the discharge current is in the approximate range from 50 to 400 amps. In another embodiment, the discharge current is in the approximate range from 90 to 300 amps. In another embodiment, the discharge current is in the approximate range from 100 to 200 amps.
[0087] In another embodiment, diborane gas (B 2 O 6 ) is introduced into the arc discharge during nanotube synthesis in order to increase boron substitution in the SWCNTs.
Post-Synthesis Boron Doping
[0088] In a second embodiment of the present invention, a method for forming boron-doped carbon nanotubes comprises the following steps:
a) providing SWCNT's; b) mixing the SWCNTs with a boron-containing and reactive material; c) reacting the SWCNTs with the boron-containing and reactive material by increasing the temperature and adding ammonia; whereby boron-doped carbon nanotubes are formed.
[0093] In one embodiment, the boron-containing and reactive material is a boron metal or boron compound such as boron carbide, boron oxides, boron nitrides, borated ceramics, borated hydrocarbons, boron glass, and boron mixtures with other neutron reactive elements and nuclides.
[0094] In another embodiment, the boron-containing and reactive material is boric oxide (B 2 O 3 ). In another embodiment, the boron-containing and reactive material is boron carbide (BC 4 ).
[0095] In one embodiment, the SWCNTs with boric oxide (B 2 O 3 ) mixture is first degassed with an inert gas, e.g., nitrogen (N 2 ) before reacting or during reaction. In other embodiments, the choice of boron-containing and reactive material may necessitate the addition of an additional carrier gas component to induce decomposition and/or reaction with the SWCNT.
[0096] In another embodiment, the system pressure is maintained at about 50 to about 1000 ton. In another embodiment, the system pressure is maintained at about 100 to about 400 torr. In another embodiment, the system pressure is maintained at about 200 torr. In another embodiment, a boron-containing compound is used to react with SWCNTs under heat and a gas is also added to the arc chamber to promote the decomposition of the B-containing chemical thereby inducing the boron-substitution.
[0097] In another embodiment, the system temperature is maintained at about 600 to about 1400 C. In another embodiment, the system temperature is maintained at about 800 to about 1200 C. In another embodiment, the system temperature is maintained at about 800 to about 1100 C. In another embodiment, the system temperature is maintained at about 800 to about 950 C. In another embodiment, the system temperature is maintained at about 825 to about 925 C. In another embodiment, the system temperature is maintained at about 900 C.
[0098] In another embodiment, the reaction time is from about 1 hour to about 24 hours. In another embodiment, the reaction time is from about 2 hour to about 8 hours. In another embodiment, the reaction time is from about 1 hour to about 4 hours.
[0099] In another embodiment, the method further comprises cooling the formed boron-doped nanotubes. In another embodiment, the method further comprises washing the boron-doped nanotubes to remove residual reactants. In another embodiment, the method further comprises dispersing the collected boron-doped nanotubes in a solvent. In another embodiment, the solvent is an alcohol. In another embodiment, the solvent is ethanol. In another embodiment, the method further comprises spraying the solvent-dispersed boron-doped nanotubes onto a substrate to form a thin film. In one embodiment, the substrate is formed of a material such as silicon, glass, quartz, silicon oxide (SiO 2 ), or aluminum oxide (Al 2 O 3 ).
[0100] In another embodiment, the SWCNTs used for the post-synthesis boron doping are produced by arc discharge, laser ablation and/or chemical vapor deposition. Nanotubes of varying purity may also be purchased from several vendors, such as Carbon Nanotubes, Inc., Carbolex, Southwest Nanotechnologies, EliCarb, Nanocyl, Nanolabs, and BuckyUSA
[0101] In selecting a solvent for a nanotube composition, the intended application for the nanotube composition is considered. The solvent meets or exceeds purity specifications required in the fabrication of intended application. The semiconductor manufacturing industry demands adherence to the specific standards set within the semiconductor manufacturing industry for ultra-clean, static-safe, controlled humidity storage and processing environments. Many of the common nanotube handling and processing procedures are simply incompatible with the industry standards. Furthermore, process engineers resist trying unfamiliar technologies. According to one aspect of the present invention, a solvent for use in a nanotube composition is selected based upon its compatibility or compliance with the electronics and/or semiconductor manufacturing industry standards.
[0102] Exemplary solvents that are compatible with many semiconducting fabrication processes, including but not limited to CMOS, bipolar, biCMOS, and MOSFET, include ethyl lactate, dimethyl sulfoxide (DMSO), monomethyl ether, 4-methyl-2 pentanone, N-methylpyrrolidone (NMP), t-butyl alcohol, methoxy propanol, propylene glycol, ethylene glycol, gamma butyrolactone, benzyl benzoate, salicyladehyde, tetramethyl ammonium hydroxide and esters of alpha-hydroxy carboxylic acids. In one or more embodiments, the solvent is a non-halogen solvent, or it is a non-aqueous solvent, both of which are desired in certain electronic fabrication processes. In one or more embodiments, the solvent disperses the nanotubes to form a stable composition without the addition of surfactants or other surface-active agents.
Alternate Boron Doping
[0103] In another embodiment, the SWCNTs used for post-synthesis boron doping are produced by arc discharge, laser ablation and/or chemical vapor deposition.
[0104] In one embodiment, boron-containing and reactive material is dissolved or suspended in nanoparticulate form in an appropriate solvent or surfactant and then a plurality of SWCNTs are added to form a mixture providing improved contact between the boron-containing and reactive material and the SWCNTs thereby improving the production of the boron-doped nanotubes.
[0105] In one embodiment, the boron-doping process comprises the steps:
(a) providing a plurality of single-walled carbon nanotubes synthesized in a process that provides for a limited amount of wall defects (reactive sites); (b) reacting a boron-containing and reactive material and single-walled carbon nanotubes in an appropriate solvent or surfactant to form a product; and (c) heating the product to a temperature of about 600 to about 1400 C for a time sufficient to produce boron-doped single-walled carbon nanotubes.
[0109] In another embodiment, the boron-doping process comprises the steps:
(a) providing a plurality of SWCNTs synthesized in a process that provides for a limited amount of wall defects (reactive sites); (b) mixing boron-containing and reactive material and SWCNTs in an appropriate solvent or surfactant to form a mixture; (c) combining the boron-containing and reactive material and SWCNTs in the mixture and allowing the material to react with the SWCNTs for an appropriate time to produce a product (a boron-SWCNT product); and (d) heating the product to a temperature of about 600 to about 1400 C for a time sufficient to produce a boron-doped SWCNT product.
[0114] Optionally, the method further comprises step (e), filtering and/or drying to obtain the SWCNT product or evaporate the solvent to produce a Boron-SWCNT product before, during or after heating in step (d). In one embodiment, the drying is by evaporating the solvent.
[0115] In another embodiment, the boron-containing and reactive material is ultrasonically dissolved in an appropriate solvent or surfactant. In another embodiment, the boron-containing and reactive material is dispersed into a metastable suspension with sufficient life to allow good mixing between nanotubes and suspension.
[0116] In another embodiment, the boron-containing and reactive material is dissolved in an appropriate solvent to form a saturated solution. In certain embodiments, the solvent may comprise an organic solvent, and in other embodiments the solvent may comprise an aqueous solvent. The method further comprises that at least one component in solution or suspension interacts (attaches, binds, etc.) to the SWCNT surface.
[0117] In one embodiment, the boron-containing and reactive material is a boron metal or boron compound such as boron carbide, boron oxides, boron nitrides, borated ceramics, borated hydrocarbons, boron glass, and boron mixtures with other neutron reactive elements and nuclides.
[0118] In another embodiment, the boron-containing and reactive material is boric oxide (B 2 O 3 ). In another embodiment, the boron-containing and reactive material is boron carbide (BC 4 ).
[0119] In another embodiment, the boron-containing and reactive material is ultrasonically dissolved in an appropriate solvent or surfactant. In another embodiment, the boron-containing and reactive material is dissolved in an appropriate solvent or surfactant to form a saturated solution. In certain embodiments, the solvent may comprise an organic solvent, and in other embodiments the solvent may comprise an aqueous solvent. The method further comprises the at least one polymer interacting with at least one SWCNT surface. In certain embodiments, the at least one polymer functionalizes the at least one carbon nanotube.
[0120] In some embodiments, the solvent comprises one selected from the group consisting of: chloroform, chlorobenzene, water, acetic acid, acetone, acetonitrile, aniline, benzene, benzonitrile, benzyl alcohol, bromobenzene, bromoform, 1-butanol, 2-butanol, carbon disulfide, carbon tetrachloride, cyclohexane, cyclohexanol, decalin, dibromethane, diethylene glycol, diethylene glycol ethers, diethyl ether, diglyme, dimethoxymethane, N,N-dimethylformamide, ethanol, ethylamine, ethylbenzene, ethylene glycol ethers, ethylene glycol, ethylene oxide, formaldehyde, formic acid, glycerol, heptane, hexane, iodobenzene, mesitylene, methanol, methoxybenzene, methylamine, methylene bromide, methylene chloride, methylpyridine, morpholine, naphthalene, nitrobenzene, nitromethane, octane, pentane, pentyl alcohol, phenol, 1-propanol, 2-propanol, pyridine, pyrrole, pyrrolidine, quinoline, 1,1,2,2-tetrachloroethane, tetrachloroethylene, tetrahydrofuran, tetrahydropyran, tetralin, tetramethylethylenediamine, thiophene, toluene, 1,2,4-trichlorobenzene, 1,1,1-trichloroethane, 1,1,2-trichloroethane, trichloroethylene, triethylamine, triethylene glycol dimethyl ether, 1,3,5-trimethylbenzene, m-xylene, o-xylene, p-xylene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, and 1,4-dichlorobenzene.
[0121] In another embodiment, the solvent is an alcohol, water or mixtures thereof. In another embodiment, the alcohol is selected from the group consisting of methanol, ethanol, 2,2,2-trifluoroethanol, 2-propanol, 2-butanol, n-pentanol, n-hexanol, cyclohexanol and n-heptanol.
[0122] “Surfactants” are generally molecules having polar and non-polar ends and which commonly position at interfaces to lower the surface tension between immiscible chemical species. Anionic, cationic or nonionic surfactants, with anionic and nonionic surfactants being more preferred, can be used in an appropriate solvent medium. Water is an example of an appropriate solvent medium. Examples of anionic surfactants include, but are not limited to SARKOSYL® NL surfactants (SARKOSYL® is a registered trademark of Ciba-Geigy UK, Limited; other nomenclature for SARKOSYL NL surfactants include N-lauroylsarcosine sodium salt, N-dodecanoyl-N-methylglycine sodium salt and sodium N-dodecanoyl-N-methylglycinate), polystyrene sulfonate (PSS), sodium dodecyl sulfate (SDS), sodium dodecyl sulfonate (SDSA), sodium alkyl allyl sulfosuccinate (TREM) and combinations thereof. A preferred anionic surfactant that can be used is sodium dodecyl sulfate (SDS). Examples of cationic surfactants that can be used, include, but are not limited to, dodecyltrimethylammonium bromide (DTAB), cetyltrimethylammonium bromide (CTAB), cetyltrimethylammonium chloride (CTAC) and combinations thereof. An example of a preferred cationic surfactant that can be used is dodecyltrimethylammonium bromide. Examples of nonionic surfactants include, but are not limited to, SARKOSYL® L surfactants (also known as N-lauroylsarcosine or N-dodecanoyl-N-methylglycine), BRIJ® surfactants (BRIJ® is a registered trademark of ICI Americas, Inc.; examples of BRIJ surfactants are polyethylene glycol dodecyl ether, polyethylene glycol lauryl ether, polyethylene glycol hexadecyl ether, polyethylene glycol stearyl ether, and polyethylene glycol oleyl ether), PLURONIC® surfactants (PLURONIC® is a registered trademark of BASF Corporation; PLURONIC surfactants are block copolymers of polyethylene and polypropylene glycol), TRITON®-X surfactants (TRITON® is a registered trademark formerly owned by Rohm and Haas Co., and now owned by Union Carbide; examples of TRITON-X surfactants include, but are not limited to, alkylaryl polyethether alcohols, ethoxylated propoxylated C 8 -C 10 alcohols, t-octylphenoxypolyethoxyethanol, polyethylene glycol tert-octylphenyl ether, and polyoxyethylene isooctylcyclohexyl ether), TWEEN® surfactants (TWEEN® is a registered trademark of ICI Americas, Inc; TWEEN surfactants include, but are not limited to, polyethylene glycol sorbitan monolaurate (also known as polyoxyethylenesorbitan monolaurate), polyoxyethylene monostearate, polyoxyethylenesorbitan tristearate, polyoxyethylenesorbitan monooleate, polyoxyethylenesorbitan trioleate, and polyoxyethylenesorbitan monopalmitate), polyvinylpyrrolidone (PVP) and combinations thereof. Preferred nonionic surfactants that can be used are alkylaryl polyethether alcohols, commercially known as TRITON-X® surfactants.
[0123] In one embodiment, the solvent comprises a surfactant and water. In another embodiment, the surfactant is selected from the group consisting of anionic surfactant, cationic surfactant and nonionic surfactant.
[0124] In another embodiment, the anionic surfactant is selected from the group consisting of N-lauroylsarcosine sodium salt, N-dodecanoyl-N-methylglycine sodium salt and sodium N-dodecanoyl-N-methylglycinate, polystyrene sulfonate, sodium dodecyl sulfate, sodium dodecyl sulfonate, sodium alkyl allyl sulfosuccinate and combinations thereof.
[0125] In another embodiment, the cationic surfactant is selected from the group consisting of dodecyltrimethylammonium bromide, cetyltrimethylammonium bromide, cetyltrimethylammonium chloride and combinations thereof.
[0126] In another embodiment, the nonionic surfactant is selected from the group consisting of N-lauroylsarcosine, N-dodecanoyl-N-methylglycine, polyethylene glycol dodecyl ether, polyethylene glycol lauryl ether, polyethylene glycol hexadecyl ether, polyethylene glycol stearyl ether, polyethylene glycol oleyl ether, block copolymers of polyethylene and polypropylene glycol, alkylaryl polyethether alcohols, ethoxylated propoxylated C 8 -C 10 alcohols, t-octylphenoxypolyethoxyethanol, polyethylene glycol tert-octylphenyl ether, polyoxyethylene isooctylcyclohexyl ether, polyethylene glycol sorbitan monolaurate, polyoxyethylene monostearate, polyoxyethylenesorbitan tristearate, polyoxyethylenesorbitan monooleate, polyoxyethylenesorbitan trioleate, and polyoxyethylenesorbitan monopalmitate, polyvinylpyrrolidone, and combinations thereof.
[0127] In another embodiment, the surfactant is sodium dodecyl sulfate. In another embodiment, the surfactant is dodecyltrimethylammonium bromide. In another embodiment, the surfactant is a selected from the group consisting of alkylaryl polyethether alcohols, ethoxylated propoxylated C 8 -C 10 alcohols, t-octylphenoxypolyethoxyethanol, polyethylene glycol tert-octylphenyl ether, polyoxyethylene isooctylcyclohexyl ether, and combinations thereof. In another embodiment, the surfactant comprises a polymer and water.
[0128] In another embodiment, the system temperature is maintained at about 600 to about 1400 C. In another embodiment, the system temperature is maintained at about 680 to about 1200 C. In another embodiment, the system temperature is maintained at about 800 to about 1100 C. In another embodiment, the system temperature is maintained at about 800 to about 950 C. In another embodiment, the system temperature is maintained at about 825 to about 925 C. In another embodiment, the system temperature is maintained at about 900 C.
[0129] In another embodiment, a carrier gas is optionally used to remove undesirable volatile reaction products. In another embodiment, the carrier gas comprises an inert gas. In another embodiment, the carrier gas comprises argon, helium, xenon, krypton, neon, oxygen, nitrogen or mixtures thereof.
[0130] In another embodiment, the boron-containing and reactive material and SWCNTs are reacted for at least 0.1, 0.5, 1, 2, or 3 or more hours.
[0131] In some embodiments of the invention, the plurality of SWCNTs form an aggregate (such as a rope or bundle).
In Situ and Post-Synthesis Boron Doping
[0132] In another embodiment of the present invention, a method for forming boron-doped carbon nanotubes comprises the following steps:
a) providing a first and second carbon sources wherein at least one carbon source is a carbon source that comprises boron; b) connecting one carbon source to a negative terminal (cathode) of the electric arc discharge supply; c) connecting a second carbon source to a positive terminal (anode) of an electric arc discharge supply; d) placing the first and second rods adjacent to each other in order to create an arc gap; e) putting the rods into an arc discharge reaction chamber, creating a vacuum in the reaction chamber, and introducing a protecting gas at a predetermined pressure therein; f) applying a discharge current between the first and second rods whereby boron-doped carbon nanotubes are formed; g) collecting the SWCNTs; and h) reacting the SWCNTs with a boron-containing and reactive material; whereby boron-doped carbon nanotubes are formed.
[0142] In another embodiment of the present invention, a method for forming boron-doped carbon nanotubes comprises the following steps:
a) providing a plurality of SWCNTs synthesized in a process that provides for a limited amount of wall defects (reactive sites); and b) reacting the SWCNTs with a boron-containing and reactive material; whereby boron-doped carbon nanotubes are formed.
[0146] In one embodiment, the boron-containing carbon source is connected to the negative terminal (cathode) of the electric arc discharge supply.
[0147] In another embodiment, the method further comprises step i) reacting the SWCNTs with the boron-containing and reactive material by increasing the temperature.
[0148] In another embodiment, the method further comprises the step of adding a carrier gas which promotes the reaction and/or carries away undesired reaction products. In one embodiment, the gas is ammonia, argon, hydrogen, methane, nitrogen, thiophene or mixtures thereof.
[0149] In one embodiment, the boron-containing and reactive material is a boron metal or boron compound such as boron carbide, boron oxides, boron nitrides, borated ceramics, borated hydrocarbons, boron glass, and boron mixtures with other neutron reactive elements and nuclides.
[0150] In another embodiment, the boron-containing and reactive material is boric oxide (B 2 O 3 ). In another embodiment, the boron-containing and reactive material is boron carbide (BC 4 ). In another embodiment, the boron-containing and reactive material is boric oxide (B 2 O 3 ) and the carrier gas is ammonia.
[0151] In another embodiment, the method further comprises refluxing the SWCNTs in an acidic environment prior to reacting with boric oxide (B 2 O 3 ). In one embodiment; the nanotubes are refluxed by placing the nanotubes in a strong acid to oxidize amorphous carbon to CO and produce defect sites in the wall of the carbon nanotube. In one embodiment; the acid is nitric acid. In one embodiment; the nitric acid is at a concentration of 1-5M. In one embodiment; the nitric acid is at 1M, 2M, 3M, 4M or more in concentration. In another embodiment the acid is a mixture of sulfuric and nitric acid. In another embodiment, the acid is hydrochloric. In another embodiment, the second carrier gas is ammonia.
[0152] In another embodiment, the method further comprises one or more steps including washing, filtering and adjusting the pH. In another embodiment, the method further comprises adjusting the pH to a neutral pH. In another embodiment, the pH is adjusted by washing with solvent. In another embodiment, the solvent is hot water.
[0153] In one embodiment, the present invention provides for a method of forming tubular carbon nanostructures which comprises discharging a direct current arc between an anode and a cathode, the anode comprising a conducting electrode containing a carbon precursor, the discharging in the presence of a gas at a temperature and pressure such that the carbon precursor is maintained in a solid phase and for a period of time sufficient to form the tubular carbon nanostructures on the anode from the carbon precursor.
[0154] In one embodiment, the carbon precursor is selected from non-graphitizable carbon and graphitizable carbon. In another embodiment, the non-graphitizable carbon includes fullerene soot, carbon black or sucrose carbon. Graphitizable carbon includes PVC.
[0155] In another embodiment, the electrodes are prepared by incorporating ˜1-10 atomic % boron as boron carbide (B 4 C) or some suitable other form, e.g., boron oxide (B 2 O 3 ), boron nitride (BN) and boron phosphide (BP), with the main ingredients, e.g., carbon and binder. The electrodes are hot pressed at 1-4 tons for 2-10 h at 200 C and then annealed at 1000 C in nitrogen gas (N 2 ) for 5-10 h.
[0156] In another embodiment, the pressure is from about 50 Torr to atmospheric. In one embodiment, the tube furnace temperature for B 2 O 3 post synthesis doping is in a range from about 650 C. to about 1200 C. In one embodiment, the gas is an inert gas or nitrogen.
[0157] The present invention also provides an apparatus for forming tubular carbon nanostructures which is preferably an arc-furnace. The apparatus comprises a cathode, an anode opposite the cathode, a source of voltage and current in an amount sufficient to create charged particles and to produce an arc between the anode and cathode, a source of gas to surround the arc, and the source of carbon precursor positioned adjacent the anode and within the arc, such that the arc has a sufficiently high temperature and is maintained at a pressure for a time sufficient to heat the carbon precursor to form carbon nanotubes upon the anode. The anode may have different geometries, e.g., flat or rounded.
[0158] The present invention also provides an apparatus for forming tubular carbon nanostructures which includes a resistance furnace having at least one opening adapted to receive a conveyor belt. The furnace further includes a source of carbon precursor, a gas source for adjusting the pressure, a heat source sufficient for the formation of tubular carbon nanostructures at the desired pressure. The conveyor belt is operably connected to the resistance furnace and is utilized to retain the source carbon precursor in the resistance furnace for a period of time sufficient to form the tubular carbon structures. Once they have been formed the conveyor belt takes the carbon nanotubes out of the resistance furnace for delivery to a user.
[0159] The present invention provides a method for making single-wall carbon nanotubes in which an arc discharge vaporizes material from an electrode comprising, consisting essentially of, or consisting of a mixture of carbon and one or more Group VI or Group VIII transition metals. In another embodiment, boron and nickel are incorporated in one or more carbon electrodes. The electrode may also incorporate one or more binders. In another embodiment, the catalyst is Fe, Co or Ni and/or their alloys. In another embodiment, a third element, e.g., Mo or a rare earth, e.g. Y is added. In another embodiment, boron and nickel-yttrium are incorporated in one or more carbon electrodes.
[0160] In one embodiment, the method also permits continuous operation, and the method produces single-wall carbon nanotubes in higher yield and of better quality. As described herein, the method may also be used to produce longer carbon nanotubes and longer ropes.
[0161] Carbon nanotubes may have diameters ranging from about 0.6 nanometers (nm) for a single-wall carbon nanotube up to 3 nm, 5 nm, 10 nm, 30 nm, 60 nm or 100 nm for single-wall or multi-wall carbon nanotubes. The carbon nanotubes may range in length from 50 nm up to 1 millimeter (mm), 1 centimeter (cm), 3 cm, 5 cm, or greater. The yield of single-wall carbon nanotubes in the product made by this invention is unusually high. Yields of single-wall carbon nanotubes greater than 10 wt %, greater than 30 wt % and greater than 50 wt % of the material vaporized are possible with this invention.
[0162] As will be described further, the one or more Group VI or VIII transition metals catalyze the growth in length of a carbon nanotube and/or the ropes. The one or more Group VI or VIII transition metals also selectively produce single-wall carbon nanotubes and ropes of single-wall carbon nanotubes in high yield. The mechanism by which the growth in the carbon nanotube and/or rope is accomplished is not completely understood. However, it appears that the presence of the one or more Group VI or VIII transition metals on the end of the carbon nanotube facilitates the addition of carbon from the carbon vapor to the solid structure that forms the carbon nanotube. Even if the mechanism is proved partially or wholly incorrect, the invention which achieves these results is still fully described herein.
[0163] Carbon nanotubes having at least one live end are formed when the target also comprises a Group VI or VIII transition metal or mixtures of two or more Group VI or VIII transition metals. In this application, the term “live end” of a carbon nanotube refers to the end of the carbon nanotube on which atoms of the one or more Group VI or VIII transition metals are located. One or both ends of the nanotube may be a live end. A carbon nanotube having a live end is initially produced in the apparatus of this invention by using an arc discharge to vaporize material from a target comprising carbon and one or more Group VI or VIII transition metals and then introducing the carbon/Group VI or VIII transition metal vapor to an annealing zone. A carbon nanotube having a live end will form in the annealing zone and then grow in length by the catalytic addition of carbon from the vapor to the live end of the carbon nanotube. Additional carbon vapor is then supplied to the live end of a carbon nanotube to increase the length of the carbon nanotube.
[0164] The carbon nanotube that is formed is not always a single-wall carbon nanotube; it may be a multi-wall carbon nanotube having two, five, ten or any greater number of walls (concentric carbon nanotubes). Preferably, though, the carbon nanotube is a single-wall carbon nanotubes.
[0165] The atmosphere in the reaction zone will comprise a carrier gas. Any gas that does not prevent the formation of carbon nanotubes will work as the carrier gas, but preferably the carrier gas is an inert gas such as helium, neon, argon, krypton, xenon, radon, or mixtures of two or more of these. Helium and Argon are most preferred. In one embodiment, the carrier gas introduced is a make-up amount of He, so that the gaseous contents of the arc chamber are turned over approximately once every 30 min. Typical chambers have volumes from about 1 to about 3 cubic feet. In another embodiment, the chamber is stainless steel and the walls are water cooled so that the temperature of the walls remains in the range about 20-40° C.
[0166] In one embodiment, the carrier gas is maintained at an internal pressure in the range from about 50-600 Torr during the synthesis process and a flow rate in the range from 100-500 sccm (standard cubic centimeters per minute). In another embodiment, the carrier gas is maintained at an internal pressure in the range from about 100-200 Ton during the synthesis process and a flow rate in the range from 200-500 sccm (standard cubic centimeters per minute).
[0167] In one embodiment, the carrier gas is a mixture of one or more inert gases combined with carbon dioxide gas (CO 2 ).
[0168] In another embodiment, the gas supplied is configured for introducing a reactant gas containing a carbon source gas into the reaction chamber for synthesizing single-wall carbon nanotubes. The carbon source gas is usually a hydrocarbon gas, such as methane, ethylene, acetylene, etc.; or a mixture of hydrocarbon gases. The reactant gas supplied also can provide hydrogen gas and/or an inert gas, which can be supplied together with the carbon source gas. The reactant gas supplier generally includes a valve for controlling a flow rate of the reactant gas.
[0169] In some embodiments of the invention, when other materials are being vaporized along with carbon, for example one or more Group VI or VIII transition metals, those compounds and vapors of those compounds will also be present in the atmosphere of the reaction zone. If a pure metal is used, the resulting vapor will comprise the metal. If a metal oxide is used, the resulting vapor will comprise the metal and ions or molecules of oxygen.
[0170] It is important to avoid the presence of too many materials that kill or significantly decrease the catalytic activity of the one or more Group VI or VIII transition metals at the live end of the carbon nanotube. It is known that the presence of too much water and/or oxygen will prevent or significantly decrease the catalytic activity of the one or more Group VI or VIII transition metals. Therefore, water and oxygen are preferably excluded from the atmosphere in the annealing zone. Ordinarily, the use of a carrier gas having less than 5 wt %, more preferably less than 1 wt % water and oxygen will be sufficient. Most preferably the water and oxygen will be less than 0.1 wt %.
[0171] In one embodiment, the electrodes are mounted inside a chamber. The reaction chamber may be made from any material that can withstand the temperatures and pressures involved. In one embodiment, stainless steel or aluminum are used.
[0172] Any Group VI or VIII transition metal may be used alone or in combination in this invention to promote CNT growth. Group VI transition metals are chromium (Cr), molybdenum (Mo), and tungsten (W). Group VIII transition metals are iron (Fe), cobalt (Co), nickel (Ni), ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), Iridium (Ir) and platinum (Pt).
[0173] In one embodiment, the one or more Group VIII transition metals are selected from the group consisting of iron, cobalt, ruthenium, nickel and platinum. In another embodiment, mixtures of yttrium and nickel are used. In another embodiment, the metallic catalyst is composed of yttrium and nickel powder in the ratio of 1:4. In one specific embodiment, the yttrium and nickel powders are mixed with powdered graphite and pressed into a graphite rod, which is then used as the cathode in an electric arc discharge. In one embodiment, the anode is made in pure graphite. In another embodiment, the catalyst is Fe, Ni, Co and mixtures thereof. In one embodiment, a 50/50 mixture (by weight) of Ni and Co is used. In one embodiment, a 50/50 mixture (by weight) of Ni and Co is mixed in a 4:1 ratio with yttrium. In another embodiment, mixtures of cobalt and nickel or mixtures of cobalt and platinum are used with yttrium.
[0174] The one or more Group VI or VIII transition metals useful in this invention may be used as pure metal, oxides of metals, carbides of metals, nitrate salts of metals, or other compounds containing the Group VI or VIII transition metal. Preferably, the one or more Group VI or VIII transition metals are used as pure metals, oxides of metals, or nitrate salts of metals. The amount of the one or more Group VI or VIII transition metals that should be combined with carbon to facilitate production of carbon nanotubes having a live end, is from 0.1 to 10 atom percent, more preferably 0.5 to 5 atom percent and most preferably 0.5 to 1.5 atom percent. In this application, atom percent means the percentage of specified atoms in relation to the total number of atoms present. For example, a 1 atom % mixture of nickel and carbon means that of the total number of atoms of nickel plus carbon, 1% are nickel (and the other 99% are carbon).
[0175] In another embodiment, the electrode comprises Ni 4 Y at 4 at. wt. % relative to carbon. In another embodiment, a carbon anode containing 10 atomic percentage of yttrium and 42 at % of nickel as catalyst is used. In yet another embodiment, the carbon, nickel and yttrium catalyst (C/Ni/Y) ratio is 94.8:4.2:1).
[0176] The one or more Group VI or VIII transition metals should be combined with carbon to form an electrode target for vaporization by an arc discharge as described herein. The remainder of the electrode should be carbon and may include carbon in the graphitic form, carbon in the fullerene form, carbon in the diamond form, or carbon in compound form such as polymers or hydrocarbons, or mixtures of two or more of these. In one embodiment, the carbon used to make the electrode is graphite.
[0177] It is understood that the apparatus can have yet another suitable configuration, such as an arc discharge apparatus with a plurality (e.g., a three or more) of the graphite electrodes installed therein to perform an arc discharge process.
[0178] Carbon is mixed with the one or more Group VI or VIII transition metals in the ratios specified and then combined to form an electrode that comprises the carbon and the one or more Group VI or VIII transition metals. The electrode may be made by uniformly mixing carbon and the one or more Group VI or VIII transition metals with carbon cement at room temperature and then placing the mixture in a mold. The mixture in the mold is then compressed and heated to about 130° C. for about 4 or 5 hours while the binder of the carbon cement cures. The compression pressure used should be sufficient to compress the mixture of graphite, one or more Group VI or VIII transition metals and carbon cement into a molded form that does not have voids; the molded form should maintain structural integrity. The molded form is then carbonized by slowly heating it to a temperature of 900° C. for about 8 hours under an atmosphere of flowing argon. The molded and carbonized targets are then heated to about 1200° C. under flowing argon for about 12 hours prior to their use as an electrode.
[0179] The invention may be further understood by reference to FIG. 2 which is a cross-section view of the arc discharge reaction chamber. An electrode is positioned within reaction chamber. The electrode will comprise carbon and may comprise one or more Group VI or VIII transition metals.
[0180] In one embodiment, the reaction chamber is positioned in oven, which in one embodiment comprises insulation and a heating element zone.
[0181] An inert gas such as argon or helium may be introduced to the upstream end of reaction chamber so that flow is from the upstream end of reaction chamber to the downstream end. In operation, oven is heated to the desired temperature, preferably 700 to 1300° C., usually about 900° C. Argon is introduced to the upstream end as a carrier gas. The argon may optionally be preheated to a desired temperature, which should be about the same as the temperature of oven. The arc discharge vaporizes the carbon electrodes. Vapor from target is carried toward the downstream end by the flowing carrier gas stream. If the target is comprised solely of carbon and boron, the vapor formed will be a carbon and boron vapor. If one or more Group VI or VIII transition metals are included as part of the target, the vapor will comprise carbon and one or more Group VI or VIII transition metals.
[0182] The heat from the oven and the flowing helium or argon maintain a certain zone within the inside of the reaction chamber as an annealing zone.
[0183] In one embodiment, the apparatus includes a water-cooled collector mounted inside the reaction chamber at the downstream end of reaction chamber. The water cooled collector may be maintained at a temperature of 700° C. or lower, preferably 500° C. or lower on the surface to collect carbon nanotubes that were formed in the annealing zone.
[0184] In one embodiment of the invention, carbon nanotubes having a live end can be caught or mounted on a tungsten wire in the annealing zone portion of reaction chamber.
[0185] In another embodiment of the invention, when the target comprises one or more Group VI or VIII transition metals, the vapor formed will comprise carbon and the one or more Group VI or VIII transition metals. That vapor will form carbon nanotubes in the annealing zone that will then be deposited on water cooled collector. The presence of one or more Group VI or VIII transition metals in the vapor along with carbon in the vapor preferentially forms carbon nanotubes instead of fullerenes, although some fullerenes and graphite will usually be formed as well. In the annealing zone, carbon from the vapor is selectively added to the live end of the carbon nanotubes due to the catalytic effect of the one or more Group VI or VIII transition metals present at the live end of the carbon nanotubes.
[0186] The annealing zone temperature in this embodiment can be lower than the annealing zone temperatures necessary to initially form the single-wall carbon nanotube having a live end. Annealing zone temperatures can be in the range of 400 to 1500° C., preferably 400 to 1200° C., most preferably 500 to 700° C. The lower temperatures are workable because the Group VI or VIII transition metal(s) catalyze the addition of carbon to the nanotube at these lower temperatures.
Purification of Single-Wall Nanotubes
[0187] Carbon nanotubes in material obtained according to any of the foregoing methods may be purified according to the methods of this invention. A mixture containing at least a portion of single-wall nanotubes (“SWCNT”) may be prepared, for example, as described by Iijima, et al, or Bethune, et al. However, production methods which produce single-wall nanotubes in relatively high yield are preferred.
[0188] The product of a typical process for making mixtures containing single-wall carbon nanotubes is a tangled felt which can include deposits of amorphous carbon, graphite, metal compounds (e.g., oxides), spherical fullerenes, catalyst particles (often coated with carbon or fullerenes) and possibly multi-wall carbon nanotubes. The single-wall carbon nanotubes may be aggregated in “ropes” or bundles of essentially parallel nanotubes.
[0189] When material having a high proportion of single-wall nanotubes is purified as described herein, the preparation produced will be enriched in single-wall nanotubes, so that the single-wall nanotubes are substantially free of other material. In particular, single-wall nanotubes will make up at least 80% of the preparation, preferably at least 90%, more preferably at least 95% and most preferably over 99% of the material in the purified preparation.
[0190] The purification process of the present invention comprises heating the SWCNT-containing felt under oxidizing conditions to remove the amorphous carbon deposits and other contaminating materials. In a preferred mode of this purification procedure, the felt is heated in an aqueous solution of an inorganic oxidant, such as nitric acid, a mixture of hydrogen peroxide and sulfuric acid, or potassium permanganate. Preferably, SWCNT-containing felts are refluxed in an aqueous solution of an oxidizing acid at a concentration high enough to etch away amorphous carbon deposits within a practical time frame, but not so high that the single-wall carbon nanotube material will be etched to a significant degree. Nitric acid at concentrations from 2.0 to 2.6 M have been found to be suitable. At atmospheric pressure, the reflux temperature of such an aqueous acid solution is about 120° C.
[0191] In a preferred process, the nanotube-containing felts can be refluxed in a nitric acid solution at a concentration of 2.6 M for 24 hours. Purified nanotubes may be recovered from the oxidizing acid by filtration through, e.g., a 5 micron pore size TEFLON filter, like Millipore Type LS. Preferably, a second 24 hour period of refluxing in a fresh nitric solution of the same concentration is employed followed by filtration as described above.
[0192] Refluxing under acidic oxidizing conditions may result in the esterification of some of the nanotubes, or nanotube contaminants. The contaminating ester material may be removed by saponification, for example, by using a saturated sodium hydroxide solution in ethanol at room temperature for 12 hours. Other conditions suitable for saponification of any ester linked polymers produced in the oxidizing acid treatment will be readily apparent to those skilled in the art. Typically the nanotube preparation will be neutralized after the saponification step. Refluxing the nanotubes in 6M aqueous hydrochloric acid for 12 hours has been found to be suitable for neutralization, although other suitable conditions will be apparent to the skilled artisan.
[0193] After oxidation, and optionally saponification and neutralization, the purified nanotubes may be collected by settling or filtration preferably in the form of a thin mat of purified fibers made of ropes or bundles of SWCNTs, referred to hereinafter as “bucky paper.” In a typical example, filtration of the purified and neutralized nanotubes on a TEFLON membrane with 5 micron pore size produced a black mat of purified nanotubes about 100 microns thick. The nanotubes in the bucky paper may be of varying lengths and may consists of individual nanotubes, or bundles or ropes of up to 103 single-wall nanotubes, or mixtures of individual single-wall nanotubes and ropes of various thicknesses. Alternatively, bucky paper may be made up of nanotubes which are homogeneous in length or diameter and/or molecular structure due to fractionation as described hereinafter.
[0194] The purified nanotubes are finally dried, for example, by baking at 850° C. in a hydrogen gas atmosphere, to produce dry, purified nanotube preparations.
[0195] In another embodiment, a slightly basic solution (e.g., pH of approximately 8-12) may also be used in the saponification step. The initial cleaning in 2.6 M HNO3 converts amorphous carbon in the raw material to various sizes of linked polycyclic compounds, such as fulvic and humic acids, as well as larger polycyclic aromatics with various functional groups around the periphery, especially the carboxylic acid groups. The base solution ionizes most of the polycyclic compounds, making them more soluble in aqueous solution. In a preferred process, the nanotube containing felts are refluxed in 2-5 M HNO3 for 6-15 hours at approximately 110-125° C. Purified nanotubes may be filtered and washed with 10 mM NaOH solution on a 3 micron pore size TSTP Isopore filter. Next, the filtered nanotubes polished by stirring them for 30 minutes at 60 C. in a S/N (Sulfuric acid/Nitric acid) solution. In a preferred embodiment, this is a 3:1 by volume mixture of concentrated sulfuric acid and nitric acid. This step removes essentially all the remaining material from the tubes that is produced during the nitric acid treatment.
[0196] Once the polishing is complete, a four-fold dilution in water is made, and the nanotubes are again filtered on the 3 micron pore size TSTP Isopore filter. The nanotubes are again washed with a 10 mM NaOH solution. Finally, the nanotubes are stored in water, because drying the nanotubes makes it difficult to resuspend them.
[0197] The conditions may be further optimized for particular uses, but this basic approach by refluxing in oxidizing acid has been shown to be successful. Purification according to this method will produce single-wall nanotubes for use as catalysts, as components in composite materials, or as a starting material in the production of tubular carbon molecules and continuous macroscopic carbon fiber of single-wall nanotube molecules.
[0198] Preparation of homogeneous populations of short carbon nanotube molecules may be accomplished by cutting and annealing (reclosing) the nanotube pieces followed by fractionation. The cutting and annealing processes may be carried out on a purified nanotube bucky paper, on felts prior to purification of nanotubes or on any material that contains single-wall nanotubes. When the cutting and annealing process is performed on felts, it is preferably followed by oxidative purification, and optionally saponification, to remove amorphous carbon. Preferably, the starting material for the cutting process is purified single-wall nanotubes, substantially free of other material.
[0199] The short nanotube pieces can be cut to a length or selected from a range of lengths, that facilitates their intended use. For applications involving the individual tubular molecules per se (e.g., derivatives, nanoscale conductors in quantum devices, i.e., molecular wire), the length can be from just greater than the diameter of the tube up to about 1,000 times the diameter of the tube. Typical tubular molecules will be in the range of from about 5 to 1,000 nanometers or longer. For making template arrays useful in growing carbon fibers of SWCNT as described below, lengths of from about 50 to 500 nm are preferred.
[0200] Any method of cutting that achieves the desired length of nanotube molecules without substantially affecting the structure of the remaining pieces can be employed. The preferred cutting method employs irradiation with high mass ions. In this method, a sample is subjected to a fast ion beam, e.g., from a cyclotron, at energies of from about 0.1 to 10 giga-electron volts. Suitable high mass ions include those over about 150 AMU's such as bismuth, gold, uranium and the like.
[0201] Preferably, populations of individual single-wall nanotube molecules having homogeneous length are prepared starting with a heterogeneous bucky paper and cutting the nanotubes in the paper using a gold (Au+33) fast ion beam.
[0202] Oxidative etching, e.g., with highly concentrated nitric acid, can also be employed to effect cutting of SWCNTs into shorter lengths. For example, refluxing SWCNT material in concentrated HNO3 for periods of several hours to 1 or 2 days will result in significantly shorter SWCNTs. The rate of cutting by this mechanism is dependent on the degree of helicity of the tubes. This fact may be utilized to facilitate separation of tubes by type, i.e., (n,n) from (m,n).
[0203] The cleaned nanotube material may be cut into 50-500 nm lengths, preferably 100-300 nm lengths, by this process. The resulting pieces may form a colloidal suspension in water when mixed with a surfactant such as Triton X-100™ (Aldrich, Milwaukee, Wis.). These sable suspensions permit a variety of manipulations such as sorting by length using field flow fractionation, and electrodeposition on graphite followed by AFM imaging. Combination of the foregoing cutting techniques can also be employed.
[0204] Homogeneous populations of single-walled nanotubes may be prepared by fractionating heterogeneous nanotube populations after annealing. The annealed nanotubes may be disbursed in an aqueous detergent solution or an organic solvent for the fractionation. Preferably the tubes will be disbursed by sonication in benzene, toluene, xylene or even molten naphthalene. The primary function of this procedure is to separate nanotubes that are held together in the form of ropes or mats by van der Waals forces. Following separation into individual nanotubes, the nanotubes may be fractionated by size by using fractionation procedures which are well known, such as procedures for fractionating DNA or polymer fractionation procedures. Fractionation also can be performed on tubes before annealing, particularly if the open ends have substituents (carboxy, hydroxy, etc.), that facilitate the fractionation either by size or by type. Alternatively, the closed tubes can be opened and derivatized to provide such substituents. Closed tubes can also be derivatized to facilitate fractionation, for example, by adding solubilizing moieties to the end caps.
[0205] Electrophoresis is one such technique well suited to fractionation of SWCNT molecules since they can easily be negatively charged. It is also possible to take advantage of the different polarization and electrical properties of SWCNTs having different structure types (e.g., arm chair and zig-zag) to separate the nanotubes by type. Separation by type can also be facilitated by derivatizing the mixture of molecules with a moiety that preferentially bonds to one type of structure.
Use of Boron-Doped SWCNTs
[0206] The nanotube composition can be placed or applied on a substrate to obtain a nanotube film, fabric or other article. A conductive article includes an aggregate of nanotubes (at least some of which are conductive), in which the nanotubes contact other nanotubes to define a plurality of conductive pathways in the article. The nanotube fabric or film desirably has a uniform porosity or density. In many applications, the nanotube fabric is a monolayer.
[0207] Many methods exist for the application procedure including spin coating, spray coating, dipping and many others known for dispersing solutions onto substrates. For thicker fabrics beyond a monolayer, more applications or more concentrated solutions may be required. In fact other techniques for application of the fabric may be required as has been outlined elsewhere (See Nanotube Films and Articles (U.S. Pat. No. 6,706,402) filed Apr. 23, 2002 and Methods of Nanotube Films and Articles (U.S. patent application Ser. No. 10/128,117) filed Apr. 23, 2002).
[0208] A further example is to coat polymer resin with the CNTs. The resultant polymer composite is then available for use as a conductive and/or reinforced material.
[0209] A further example of an application in which CNTs may be used is to form an EMI (Electro Magnetic Interference) shield. The CNTs may be formed in a composite material (e.g. glass, metal, ceramic, polymer, graphite or any combination of these), wherein the composite material is then able to shield devices or people from RF or microwave radiation.
[0210] The B-SWCNTs may also be deposited on a paper substrate to form a circuit. The paper circuit may then be used as a biodegradable electronic device, which is easily and cheaply manufactured, and can be thrown away when no longer required.
[0211] CNTs have special qualities such as good electrical and thermal conductivity and resistance to temperature. Ropes of CNTs have good tensile strength, which is useful in applications where durability are required. Also, as carbon is not easily detectable, it is also possible to make CNT circuits that can be hidden.
[0212] The tubular carbon molecules of this invention may also be used in RF shielding applications, e.g., to make microwave absorbing materials.
[0213] Single-walled nanotube molecules may serve as catalysts in any of the reactions known to be catalyzed as fullerenes, with the added benefits that the linear geometry of the molecule provides. The carbon nanotubes are also useful as supports for catalysts used in industrial and chemical processes such as hydrogenation, reforming and cracking catalysts. Materials including the SWCNT molecules can also be used as hydrogen storage devices in battery and fuel cell devices.
[0214] The tubular carbon molecules produced according to this invention can be chemically derivatized at their ends (which may be made either open or closed with a hemi-fullerene dome). Derivatization at the fullerene cap structures is facilitated by the well-known reactivity of these structures. See, “The Chemistry of Fullerenes” R. Taylor ed., Vol. 4 of the advanced Series in Fullerenes, World Scientific Publishers, Singapore, 1995; A. Hirsch, “The Chemistry of the Fullerenes,” Thieme, 1994. Alternatively, the fullerene caps of the single-walled nanotubes may be removed at one or both ends of the tubes by short exposure to oxidizing conditions (e.g., with nitric acid or O2/CO2) sufficient to open the tubes but not etch them back too far, and the resulting open tube ends maybe derivatized using known reaction schemes for the reactive sites at the graphene sheet edge.
[0215] Process parameters, including but not limited to, voltage, temperature, current density, and gas pressure, are selected that are appropriate for forming SWCNTs at an efficient rate without harming or otherwise damaging the semiconducting or metallic carbon nanotubes.
[0216] Since the period of applying the voltage depends on the discharge voltage, the discharge environment, the state of the magnetic field, the various temperatures, the shape and the type of the electrodes and the like, and thus, is not generalized, the period should be properly selected. When it is necessary to control the average length of the manufactured carbon nanotubes more precisely, the discharge period realizing the desired length of the carbon nanotubes is selected after the working curve for the discharge period and the average length of the carbon nanotubes is obtained in advance.
[0217] When the discharge plasma is generated between the electrodes, carbon is separated from the surface of the electrode, and then reacts to generate carbon nanotubes. The generated carbon nanotubes are deposited on the surface of the tip of the electrode, a neighborhood of it, and also the inner wall of the reaction container.
[0218] In one embodiment, a cooling unit (a heat releasing member and tubes) is provided to cool the magnets and it is possible to maintain stably generating discharge plasma for a long period.
[0219] In general, when carbon nanotubes are manufactured with arc discharge or the like, amorphous carbon, graphite particles, and the like are generated simultaneously with the carbon nanotubes. Namely, since other impurities are generated along with the carbon nanotubes, the supplied carbon source does not always contribute to the growth of the carbon nanotubes.
[0220] As described above, with the present invention, by manufacturing carbon nanotubes with discharge plasma such as arc discharge which enables simple manufacturing and requires only low cost, it is possible to obtain high purity carbon nanotubes while properly controlling the shape, especially the length and diameter.
[0221] The unique properties of the nano-carbon fiber produced by the present invention also permit new types of composite reinforcement. It is possible, for example, to produce a composite fiber/polymer with anisotropic properties. This can, for example, be accomplished by dispersing a number of metallic carbon nanotube fibers (e.g., from (n,n) SWCNTs) in a prepolymer solution (e.g., a poly methymethacrylate) and using an external electric field to align the fibers, followed by polymerization. Electrically conductive components can also be formed using the metallic forms of carbon nanotubes.
[0222] Applications of these carbon nanotubes containing composites include, but are not limited to, all those currently available for graphite fibers and high strength fibers such as Kevlar, including: structural support and body panels and for vehicles, including automobiles, trucks, and trains; tires; aircraft components, including airframes, stabilizers, wing skins, rudders, flaps, helicopter rotor blades, rudders, elevators, ailerons, spoilers, access doors, engine pods, and fuselage sections; spacecraft, including rockets, space ships, and satellites; rocket nozzles; marine applications, including hull structures for boats, hovercrafts, hydrofoils, sonar domes, antennas, floats, buoys, masts, spars, deckhouses, fairings, and tanks; sporting goods, including golf carts, golf club shafts, surf boards, hang-glider frames, javelins, hockey sticks, sailplanes, sailboards, ski poles, playground equipment, fishing rods, snow and water skis, bows, arrows, racquets, pole-vaulting poles, skateboards, bats, helmets, bicycle frames, canoes, catamarans, oars, paddles, and other items; mass-produced modular homes; mobile homes; windmills; audio speakers; furniture, including chairs, lamps, tables, and other modern furniture designs; soundboards for string instruments; lightweight armored products for personnel, vehicle, and equipment protection; appliances, including refrigerators, vacuum cleaners, and air conditioners; tools, including hammer handles, ladders, and the like; biocompatible implants; artificial bones; prostheses; electrical circuit boards; and pipes of all kinds.
EXAMPLES
Example 1
B-SWCNT Material Characterization (e.g., B-Content in the Tube Wall)
[0223] The B-content in the SWCNTs has been determined by transmission electron microscopy (EELs) and neutron activation methods. Some fraction ˜½ of the boron in the electrodes is preferentially lost to carbon particles and amorphous carbon also produced in the ARC reaction. Electrical conductivity measurements in thin films of tangled bundles of SWCNTs deposited on glass substrates indicate a factor of 2-10 increase in the conductivity within the sheet. Raman scattering studies of the B-SWCNTs show an increase in D-band strength (˜1350 cm −1 ) that correlates with the amount of boron introduced into the electrode. The sharp line character of the nanotube G-band is maintained upon B-doping, indicating that the B-substitution maintains the integrity of the structure in the tube wall. So-called van Hove (H) optical absorption bands are observed in the B-SWCNTs, but they appear upshifted in photon energy relative to their positions in pristine tubes when the B-doping is high. The upshift increases with increasing B-content in the electrodes. The vH features are only characteristic of one-dimensional filaments (e.g., carbon nanotubes). These vH features are, therefore, not present in the optical spectra of other carbons produced in the arc (e.g., amorphous carbon carbon onions, carbon shells, graphitic flakes).
[0224] Thus, it can be seen that the objects of the invention have been satisfied by the structure and its method for use presented above. It is to be understood that the invention is not limited thereto or thereby. Accordingly, for an appreciation of true scope and breadth of the invention, reference should be made to the following claims. | The present invention generally relates to methods and apparatus for the synthesis or preparation of boron-doped single-walled carbon nanotubes (B-SWCNTs). The invention provides a high yield, single step method for producing large quantities of continuous macroscopic carbon fiber from single-wall carbon nanotubes using inexpensive carbon feedstocks wherein the carbon nanotubes are produced by in situ boron substitutional doping. In one embodiment, the nanotubes disclosed are used, singularly or in multiples, in power transmission cables, in solar cells, in batteries, as antennas, as molecular electronics, as probes and manipulators, and in composites. It is another object of this invention to provide macroscopic carbon fiber made by such a method. | 2 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a phase difference control component comprising a liquid crystal material, which has excellent symmetry with respect to the angle of visibility and is optically compensable, and a process for producing the same, and a liquid crystal display device comprising said phase difference control component.
[0003] 2. Background Art
[0004] Color liquid crystal displays (hereinafter often referred to as “LCDs”) have features such as thin shape, light weight, low power consumption, and flickerless, and the market of color liquid crystal displays for PCs including notebook computers has been rapidly grown. In recent years, regarding displays for PCs, there is an increasing demand for desktop monitors which are larger in size than notebook computers. Further, LCDs have become utilized in PCs, as well as in TVs for which CRTs have hitherto been mainly utilized.
[0005] A small angle of visibility is a problem inherent in LCDs. This problem is caused by light leakage from pixels, which should originally display black, when LCDs are viewed in an oblique direction. Due to this light leakage, the inversion of contrast takes place, and proper display becomes impossible. As a result, the angle of visibility is lowered.
[0006] In order to solve the above problem, LCDs with a high angle of visibility using a phase different film have been proposed. The phase difference film is also used in combination with a linear polarization plate for creating various polarized states. For example, circularly polarized light can generally be constituted by a combination of a linearly polarizing plate with a λ/4 (quarter-wave) phase difference plate.
[0007] In these phase difference films, transparent polymeric films such as polycarbonate films subjected to stretching treatment such as monoaxial stretching have hitherto been used. In addition to these film, films formed by aligning and fixing a liquid crystal material having refractive index anisotropy while imparting given regularity can also be used. The phase difference film using a liquid crystal material can constitute, through alignment control of liquid crystal molecules, positive and negative A plates, positive and negative C plates, and a phase difference layer with hybrid alignment in which the aligned state is continuously varied (see, for example, Japanese Patent Laid-Open No. 153712/1999).
[0008] An aligning film subjected to alignment treatment is necessary for horizontally aligning liquid crystal molecules against a base material in a monoaxial direction. In general, polyimide films subjected to rubbing treatment are generally used as the aligning film. When liquid crystal molecules are aligned in a rubbing direction on the aligning film subjected to rubbing treatment, a pretilt angle (an angle of liquid crystal molecules to the base material) is created so that the end of the liquid crystal molecules are lifted in the rubbing direction relative to the base material. This pretilt angle plays an important role in regulating the liquid crystal molecules so that, upon voltage application, the liquid crystal molecules are lifted unidirectionally. Therefore, the presence of a pretilt angle in the liquid crystal molecules is indispensable, and, at the same time, the pretilt angle should be controlled.
[0009] When a fixed liquid crystal material is used as the phase difference control component, however, the presence of a pretilt angle in liquid crystal molecules causes a change in the level of phase difference to become asymmetrical with respect to the vertical direction upon a change in angle of visibility in a direction other than the phase advance axis. In particular, when the angle of visibility is varied in an optical axis direction of liquid crystal molecules, the asymmetry of a change in level of the phase difference is most significant.
[0010] Specifically, in the formation of an aligning film by the conventional rubbing method, as shown in FIG. 2 , an aligning film 22 is coated on a base material 21 ( FIG. 2 ( a )). The aligning film is rubbed, for example, by a rubbing roller 23 or the like ( FIG. 2 ( b )). Next, a liquid crystal material is coated on the aligning film subjected to rubbing treatment. Molecular liquid crystals 24 make a pretilt angle θ with the direction of rotation of the rubbing roller 23 for alignment ( FIG. 2 ( c )).
[0011] For this reason, when the level of phase difference is measured by varying the observation angle in a direction other than the phase advance axis, the level of the phase difference is asymmetrical with respect to 0 (zero) degree (vertical direction). In particular, when the level of phase difference is measured by varying the observation angle in the direction of the slow phase axis, the asymmetry of the level of the phase difference is most significant. For this reason, a liquid crystal display device to which a phase difference control component formed of a liquid crystal material with a pretilt angle θ has been applied, suffers from a problem that, except for a change in observation angle in the phase advance axis, display images are different.
[0012] Since the pretilt angle also propagates in the thickness-wise direction of the film, when the phase difference layer comprises a plurality of liquid crystal layers stacked on top of each other, the alignment at the interface of the liquid crystal layers is adversely affected.
[0013] For oblique compensation of angle of visibility, the necessary phase difference level should be calculated for design of the phase difference control component. When the level of the symmetry of the angle of visibility is low, a desired phase difference level can be realized only in any one direction and a phase difference control component, which can realize a satisfactorily large angle of visibility, cannot be provided.
[0014] In large-size liquid crystal televisions, due to properties of angle of visibility within a display face attributable to the large area, the symmetry of the angle of visibility poses a severe problem.
SUMMARY OF THE INVENTION
[0015] The present inventors have now found that, when the pretilt angle of liquid crystal molecules constituting a phase difference control component is substantially 0 (zero) degree, the asymmetry of the phase difference does not occur. The present invention has been made based on such finding.
[0016] Accordingly, an object of the present invention is to provide a phase difference control component, which has excellent phase difference symmetry and is optically compensable, capable of realizing a liquid crystal display device having a wide angle of visibility, and a process for producing the same.
[0017] The phase difference control component according to the present invention comprises: a base material; and a phase difference control layer formed of a fixed liquid crystal material provided on said base material through an aligning film, characterized in that
[0018] the angle of liquid crystal molecules, present at the interface of the aligning film and the phase difference control layer, to the base material is substantially 0 (zero) degree.
[0019] The process for producing a phase difference control component according to the present invention is characterized by comprising at least the steps of:
[0020] forming an aligning film on a base material; and
[0021] providing a liquid crystal material on said aligning film and applying alignment controlling force to the liquid crystal material to form a phase difference control layer,
[0022] the application of the alignment controlling force to the liquid crystal material being carried out by a photoalignment method in which collimated deflected light is applied to the alignment film from the vertical direction.
[0023] In the present invention, the expression “a pretilt angle of substantially 0 degree” means that, although, when liquid crystal molecules are microscopically observed, the liquid crystal molecules are very slightly tilted against the base material surface, since there is no regularity in the direction of lifting of the tilt, when the liquid crystal molecules are macroscopically observed, lifting angles are offset and, consequently, the pretilt angle is observed to be 0 degree.
[0024] In the phase difference control component according to the present invention, any pretilt angle does not exist in the liquid crystal molecules constituting the phase difference member. Therefore, the level of the phase difference symmetry is so high that the angle of visibility of the liquid crystal display device can be effectively increased. Further, a liquid crystal display device, which is excellent in symmetry of the angle of visibility, can be realized.
[0025] Further, in the process according to the present invention, in constructing a phase difference control component using a liquid crystal material, a phase difference layer having a pretilt angle of substantially 0 degree can be formed by using a photoalignment method and applying ultraviolet light in the vertical direction. Therefore, when the level of phase difference is measured by varying the observation angle in the slow phase axis direction, highly symmetrical phase difference control can be realized and, thus, a phase difference control component which can realize higher-accuracy optical compensation can be provided.
[0026] Further, according to the present invention, when the phase difference control component is stacked directly on a color filter, a higher-performance phase difference control component free from shrinkage with the elapse of time and peel-off which are problems of the conventional film-type phase difference control component can be provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a cross-sectional view illustrating a production process of a phase difference control component comprising a liquid crystal material by a photoalignment method according to the present invention;
[0028] FIG. 2 is a cross-sectional view illustrating the step of aligning an aligning film by the conventional rubbing method;
[0029] FIG. 3 is an explanatory view illustrating the case where the level of the phase difference is measured by varying the observation angle in the slow phase axis direction to positive values and negative values relative to 0 degree;
[0030] FIG. 4 is a diagram showing the results of measurement of retardation values (RE; nm) representing the level of phase difference by varying the observation angle (an elevation angle) of a phase difference control component in the working example in the range of −45 degrees to +45 degrees in the slow phase axis direction; and
[0031] FIG. 5 is a diagram showing the results of measurement of retardation values (Re in nm) representing the level of phase difference by varying the observation angle (an elevation angle) of a phase difference control component in the range of −45 degrees to +45 degrees in the slow phase axis direction by the conventional rubbing method for comparison with the working examples of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0032] Embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0033] The phase difference control component according to the present invention has a structure comprising a phase difference control layer provided on a base material through an aligning film. Individual layers constituting the phase difference control component according to the present invention will be descried.
[0034] Base Material
[0035] As shown in FIG. 1 ( a ), a base material 11 on which an aligning film 12 is provided is either an inorganic base material, for example, a glass substrate formed of glass or quartz or silicon, or an organic base material.
[0036] Organic base materials include plastic substrates or films formed of polymethyl methacrylate or other acrylic resins, polyamides, polyacetals, polybutylene terephthalates, polyethylene terephthalates, polyethylene naphthalates, triacetylcelluloses, syndiotactic polystyrenes, polyphenylene sulfides, polyether ketones, polyether ether ketones, fluororesins, polyethernitriles, polycarbonates, modified polyphenylene ethers, polycyclohexenes, polynorbornenes resins, polysulfones, polyethersulfones, polysulfones, polyallylates, polyamide-imides, polyetherimides or thermoplastic polyimides. However, it should be noted that the organic base material is not limited to those described above and conventional plastic films and the like may also be used.
[0037] Further, the above-described glass substrates, plastic substrates and substrates comprising a color filter provided on a film may also be used as the base material.
[0038] The thickness of the base material 11 is not particularly limited and may vary depending upon applications, and, for example, base material having a thickness of about 1 nm to 5 μm may be used.
[0039] A substrate provided with a color filter may also be used as the base material. For example, a construction may also be adopted in which an aligning film is provided on a color filter and a phase difference control layer formed of a liquid crystal material is then stacked.
[0040] Aligning Film
[0041] The aligning film used in the present invention may be formed by the following method. A solution of an aligning film material dissolved in a solvent is prepared. This solution is coated onto the base material 11 by spin coating, flexographic printing or the like to form a coating film. Thereafter, the solvent is removed from the coating film to form an unaligned aligning film. Next, the aligning film is subjected to alignment treatment. Alignment methods usable in the present invention for bringing the pretilt angle of liquid crystal molecules to substantially 0 degree include photoalignment, and rubbing treatment for aligning liquid crystal molecules in a direction perpendicular to the rubbing direction.
[0042] FIG. 1 ( b ) shows the step of subjecting an aligning film by photoalignment to alignment treatment. Specifically, collimated polarized light (ultraviolet light) 13 is applied to the aligning film 12 provided on the base material 11 for alignment of the aligning film 12 by photoalignment. In the present invention, alignment methods using the photoalignment are roughly divided into photoisomerization types and photoreaction types according to the reaction mechanism. Photoreaction types are further subdivided into dimerization types, decomposition types, bonding types and the like.
[0043] One example of the photoisomerization type is azobenzene which causes cis-trans isomerization. Azobenzene absorbs ultraviolet light of an electric field vector parallel to the molecular axis and consequently is converted from trans form to cis form. Liquid crystal molecules are aligned parallel to azobenzene in trans form and thus are aligned in a direction perpendicular to the polarization direction of ultraviolet light. Accordingly, an aligning film having a pretilt angle of substantially 0 degree can be prepared.
[0044] Photoreaction types include dimerization of polyvinyl cinnamate, decomposition of polyimide resin, and bonding of polyimide having a benzophenone skeleton. All of these methods can form aligning films having a pretilt angle of 0 degree.
[0045] A rubbing technique for aligning liquid crystal molecules in a direction vertical to the rubbing direction may be mentioned as another alignment method for brining the pretilt angle of liquid crystal molecules to substantially 0 degree.
[0046] For example, conventional aligning films disclosed in Japanese Patent Laid-Open Nos. 62427/2002 and 268068/2002 may be used as the aligning film in this method. Specifically, aligning films, in which the pretilt angle of liquid crystal molecules is substantially 0 degree, can be prepared by using modified polyvinyl alcohols or polyimide or polyamic acid having a carbazole skeleton on its side chain.
[0047] Phase Difference Control Layer
[0048] In the present invention, the phase difference control layer 14 provided on the aligning film 12 is formed of a liquid crystal material. After the alignment treatment, the liquid crystal material should be fixed while maintaining the alignment. FIG. 1 ( c ) shows a phase difference control layer 14 in such a state that liquid crystal molecules 15 have been aligned to a pretilt angle of substantially 0 degree. In the drawing, the liquid crystal molecules 15 are shown in a typically enlarged state.
[0049] Subsequently, the liquid crystal material is fixed while holding the alignment of the liquid crystal molecules 15 . In this case, from the above viewpoint, preferred liquid crystal materials include polymeric liquid crystal materials, which have a glass transition temperature and, at a temperature below the glass transition temperature, can realize fixation of the liquid crystal structure, and photopolymerizable liquid crystal materials which can be cured by three-dimensional crosslinking upon exposed to ultraviolet light.
[0050] Monomer molecules which are three-dimensionally crosslinkable upon exposure to ultraviolet light include a mixture of a liquid crystal monomer and a chiral compound, as disclosed, for example, in Japanese Patent Laid-Open No. 258638/1995 and Published Japanese Translation of PCT Publication No. 508882/1998. For example, compounds represented by the following formulae (I) to (XI) or a mixture composed of two or more of them are suitable for use as the photopolymerizable liquid crystal material. In the liquid crystal monomer represented by formula (XI), preferably, X is 2 to 5 (integer).
[0051] Compounds having chemical structures represented by the following formulae (XII) to (XIV) are suitable as chiral agents.
[0052] In the chiral agents represented by formulae (XII) to (XIII), Y represents any one substituent selected from substituents represented by the following formulae (i) to (xxiv) and R 4 represents hydrogen or a methyl group. X is preferably 2 to 12 (integer).
[0053] In the chiral agent represented by formula (XIV), X is preferably 2 to 5 (integer).
[0054] The phase difference control layer 14 may be formed by providing the above photopolymerizable liquid crystal material or polymeric liquid crystal material, optionally dissolving or diluting the material with a solvent, coating the material onto a base material by spin coating, die coating, slit coating or other proper method, and removing the residual solvent, for example, by heat drying. Thereafter, a liquid crystal structure in which liquid crystal molecules have been aligned at a pretilt angle of substantially 0 degree is developed in the liquid crystal material.
[0055] When a photopolymerizable liquid crystal material is used, as shown in FIG. 1 ( d ), ultraviolet light 16 is then applied to polymerize the photopolymerizable liquid crystal material, whereby a phase difference control layer 14 formed of a liquid crystal material, which holds a liquid crystal structure with liquid crystal molecules aligned at a pretilt angle of substantially 0 degree, can be formed.
[0056] In the present invention, preferably, the phase difference control layer has positive birefringence properties, and the optical axis thereof is parallel to the plane of the phase difference control layer.
[0057] In the present invention, a two-layer construction may also be adopted in which a second phase difference control layer, which has negative birefringence properties and has an optical axis perpendicular to the plane of the phase difference control component is stacked on the phase difference control layer which has positive birefringence properties and has an optical axis parallel to the plane of the phase difference control component.
[0058] Further, in the present invention, another two-layer construction may also be adopted in which a second phase difference control layer, which has positive birefringence properties and has an optical axis perpendicular to the plane of the phase difference control layer is stacked on a first phase difference control layer which has positive birefringence properties and has an optical axis parallel to the plane of the phase difference control layer.
[0059] The phase difference control component according to the present invention, together with a color filter, may constitute a laminate structure. For example, when a phase difference control layer having an optical axis parallel to the plane of the phase difference control layer is stacked on a color filter, a method may be adopted in which a photopolymerizable liquid crystal composition comprising a photopolymerization initiator incorporated in a polymerizable liquid crystal monomer is coated onto one side of a color filter to form a coating which is then exposed to ultraviolet light or the like to form a continuous one layer stacked on the color filter. On the other hand, when a phase difference control layer having an optical axis perpendicular to the plane of the phase difference control layer is stacked, this layer can be formed in the same manner as described above, except that a photopolymerizable liquid crystal composition containing a polymerizable chiral agent is used.
[0060] The laminate structure in which the phase difference control component is stacked directly on the color filter can realize a high-performance phase difference control component free from shrinkage with the elapse of time and peeling which are problems of the conventional film-type phase difference control component.
[0061] In forming the phase difference control component on the color filter, in some cases, the underlying color filters are different from each other in thickness depending upon color patterns of red, blue, and green, that is, the surface of the color filters is uneven. In this case, preferably, a method is adopted in which the color filter is flattened by providing a transparent flattening layer on the color filter and the phase difference control component is then formed on the flattening layer.
[0062] Further, in an embodiment of the present invention, a color filter is stacked on a phase difference control component.
EXAMPLES
[0063] The following Examples further illustrate the present invention. However, it should be noted that the present invention is not limited to these Example.
[0000] 1. Preparation of Base Material With Aligning Film
[0064] A glass substrate (1737 glass, manufactured by Corning Inc.) which had been cleaned by a predetermined method was provided as a base material, and AL 1254 (manufactured by JSR Corporation) was provided as an aligning film material. The aligning film material was coated by flexographic printing onto the glass substrate to form a 600 angstrom-thick aligning film.
[0065] Next, polarized ultraviolet light was applied to the aligning film at 5 J/cm 2 in a direction vertical to the base material to form an aligning film by a photoalignment method to which monoaxial anisotropy had been imparted.
[0066] For comparison, a base material provided with an aligning film subjected to the conventional rubbing treatment was prepared.
[0000] 2. Preparation of Ink for Phase Difference Control Layer
[0067] Ultraviolet-curable acrylate group-containing RMM 34 (manufactured by Merck & Co., Inc.) was used as a liquid crystal material for phase difference control layer formation. 20 parts by weight of RMM 34 was dissolved in propylene glycol monomethyl ether acetate as a solvent to prepare a composition for phase difference control layer formation.
[0000] 3. Formation of Phase Difference Control Layer
[0068] Next, the composition for phase difference control layer formation prepared above was spin coated onto the base material with the aligning film formed thereon by the photoalignment method. For comparison, the same composition was coated on the base material with the aligning film formed thereon by the rubbing method.
[0069] Both the substrates with the composition coated thereon were heated on a hot plate at 100° C. for 5 min to remove the residual solvent and thus to develop a liquid crystal structure. Next, ultraviolet light was applied (500 mJ/cm 2 , 365 nm) to fix the liquid crystal structure and thus to form a phase difference control layer.
[0070] Thus, phase difference control components comprising a phase difference control layer provided on a base material through an aligning film were prepared.
[0000] 4. Measurement of Level of Phase Difference in Phase Difference Control Component
[0071] Next, for the phase difference control components, retardation values (RE; nm) representing the level of phase difference were measured by varying the observation angle (an elevation angle) in the range of −45 degrees to +45 degrees in the slow phase axis direction. RFTS-3100 VA, manufactured by Otsuka Electronics Co., Ltd. was used for the measurement. The results of measurement are shown in FIGS. 4 and 5 .
[0072] FIG. 4 shows the results of measurement for the phase difference control component according to the present invention prepared by forming an aligning film by photoalignment and providing a phase difference control layer formed of a liquid crystal material on the aligning film. FIG. 5 shows the results of measurement for the comparative phase difference control component prepared by forming an aligning film by the conventional rubbing method and providing a phase difference control layer formed of a liquid crystal material on the aligning film.
[0073] In the case of the photoalignment method shown in FIG. 4 , phase difference properties are symmetrical with respect to the angle of visibility. On the other hand, as can be seen from FIG. 5 , in the case of the aligning film formed by the rubbing method, phase difference properties are asymmetrical. These results show that, in the phase difference control component according to the present invention prepared by the photoalignment method, bringing the pretilt angle of liquid crystal molecules constituting the phase difference layer to substantially 0 degree can realize a high level of symmetry of the phase difference and an effective increase in angle of visibility.
[0074] Further, a liquid crystal display device prepared using the phase difference control component by the photoalignment method according to the present invention shown in FIG. 4 exhibited display which was excellent in symmetry of the angle of visibility. | There are provided a phase difference control component, which can realize a liquid crystal display device having a wide angle of visibility, has excellent phase difference symmetry and can realize optical compensation, and a process for producing the same. The phase difference control component comprises a base material; and a phase difference control layer formed of a fixed liquid crystal material provided on the base material through an aligning film and is characterized in that the angle of liquid crystal molecules, present at the interface of the aligning film and the phase difference control layer, to the base material being substantially 0 (zero) degree. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to radiant tube heating systems and, in particular, to such a system which incorporates catalytic combustion and air preheating capabilities.
Radiant tube heating systems are used primarily for heat treating various fluids and materials, usually in a controlled ambient such as an inert gas or a vacuum. For example, Kendall et al U.S. Pat. No. 4,204,829 discloses a catalytic combustion tube heating system which provides radiant heating of a fluid heat sink, such as water, for extraction of the energy at an external heat exchanger.
However, to our knowledge, gas-fired radiant tube combustors employing high temperature heterogeneous catalytic combustion have not existed previously. Such a gas-fired radiant tube would be useful in many industrial process heating furnace applications. Presently, industrial process heating furnaces may typically employ conventional gas burners which fire into one end of a tube and, in particular, electric resistance elements, as sources of radiant heat. The electric resistance elements provide certain desirable operating characteristics including high temperatures (2,000° F. and above), precise temperature control and relatively high firing rates (Btu/hr).
A gas-fired radiant tube employing high temperature heterogeneous catalytic combustion would be highly desirable for such industrial process heating furnaces and other similar applications because of potential catalytic combustion advantages such as low emissions levels and uniform radiant energy transfer. However application of such gas-fired radiant tube combustors imposes the requirements of high combustion efficiency and high system thermal efficiency in addition to those of uniform radiant energy transfer and low emission levels.
To our knowledge, the radiant tube heating technology has not previously had available a simple catalytic combustion radiant tube heating system which efficiently satisfies the above requirements.
SUMMARY OF THE INVENTION
In view of the above discussion, it is a primary object of the present invention to provide a gas-fired radiant tube combustor employing high temperature heterogeneous catalytic combustion, the operation of which is characterized by uniform radiant energy transfer, low emission levels and high volumetric heat release rates.
It is another primary object of the present invention to provide a catalytic combustion, radiant tube heating system, the operation of which is characterized by high combustion efficiency and high thermal efficiency, as well as by uniform radiant energy transfer, and low NO x emission levels.
In one aspect, the above objectives are achieved in a catalytic combustion, gas-fired radiant tube comprising a ceramic tube having a combustion catalyst such as platinum coated on its inside surface for providing high temperature heterogeneous catalytic combustion.
In another aspect, the above objectives are achieved in a radiant tube heating system which incorporates a radiative catalytic combustion chamber, as described above, having a combustion flow path therethrough and a pair of substantially identical, inlet and outlet units which feed into opposite ends of the combustion flow path. Each inlet/exhaust unit comprises a conduit which is connected to the combustion chamber flow path, a fuel inlet, a heat regenerator, and an air inlet and an exhaust outlet which can be selectively opened and closed.
In a preferred method of operation, the two air inlets and the two exhaust outlets are selectively opened and closed so that air and fuel mixture from one inlet/exhaust unit is ignited and passed through the catalytic combustion chamber, then transmitted to the regenerator of the second inlet/exhaust unit and exhausted from that unit, thereby heating the second regenerator. The flow is then reversed through the system, from the second input/exhaust unit through the combustion chamber and then through the regenerator and the exhaust of the first unit. During this second, reversed-flow cycle, the previously-heated second regenerator preheats the inlet air prior to combustion, thereby increasing the combustion efficiency, while the first regenerator is heated by the exhaust flow preparatory to the initiation of the first cycle. In short, in each cycle of the two-cycle operation, the regenerator in the inlet side preheats the inlet air to increase combustion efficiency in that cycle, while the exhaust-side regenerator is heated preparatory to preheating the inlet air during the next, reverse-flow cycle.
Thus, the present catalytic combustion, gas-fired radiant tube and the associated reverse cycling system and process adapt radiant tube heating technology to the use of catalytic combustion and extract high combustion and thermal efficiency and provide uniform radiant energy transfer, while suppressing NO x emissions to low levels.
In a presently preferred embodiment, the two air inlets and the two exhaust outlets are controlled by valves which selectively open and close the associated inlet and exhaust paths. The valves can be manually operated. However, in systems where the cycle time is short, it is preferable to incorporate a timer-, or computer-, or controller-operated valving system.
BRIEF DESCRIPTION OF THE DRAWING
The above and other aspects of the invention are described in the drawings, in which:
FIG. 1 schematically depicts a preferred embodiment of our dual preheating unit, catalytic combustion radiant thermal heating system; and
FIG. 2 schematically depicts a box furnace which employs the gas-fired radiant tubes of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Construction of Radiant Tube Heating System 10
As shown in the figure, our radiant tube heating system 10 comprises a radiant heating chamber 11 which includes a tube-type catalytic combustor 12 which extends through the insulated walls 13 of the chamber. Typically, the walls 13 are made of insulating material such as refractory brick. Radiant energy emitted from the combustor 12 is absorbed by heat sink material such as heat exchanger fluid or a metal "workpiece" (not shown) within the chamber 11, thereby heating the material. The chamber 11 may be provided with a controlled gaseous environment such as nitrogen or a vacuum for purposes such as heat treating a product. As shown, the tubular catalytic combustion chamber 12 may comprise a ceramic tube 14 coated with a layer of surface-active catalyst, e.g., a noble metal such as platinum and honeycombs 16--16 which are spaced within the tube 14 and are also coated with the catalyst. The choice of a particular catalyst material depends upon the desired application and its operating conditions and requirements.
In a presently preferred working embodiment, our tube-type catalytic combustor 12 comprised a twenty-two inch long, 1.75 inch outside diameter, thin walled ceramic (silicon carbide) tube that was coated on its inside surface with a platinum combustion catalyst. The operational characteristics of this combustor 12 were demonstrated by a series of tests in which a near stoichiometric (91% TA to 130% TA) mixture of natural gas and preheated air (preheated to 830° F. to 1060° F.) was passed through the tube. The reactants burned catalytically on the inside surface of the tube wall, which caused the tube wall to be heated to almost 2000° F. The operational parameters and the results are summarized in the accompanying table.
__________________________________________________________________________SUMMARY OF TEST RESULTSINDEPENDENT VARIABLESPreheat Firing Stoich-Tube Temperature Rate iometry Emissions UHC DEPENDENT VARIABLES(Coating)(°F.) (MBtu/hr) (% TA) O2 (%) CO2 (%) (ppm × 10.sup.3) CO (ppm) Temperatures__________________________________________________________________________Platinum830 23.5 130 13.8 3.3 45 61 19451060 23.5 91 7.5 4.5 65 3.8% 1958879 23.5 121 12.5 4.2 47 200 >1999948 24.7 101 10.0 5.5 50 195 >1999950 25.8 97 9.5 5.1 54 200 >1999__________________________________________________________________________
One of the most important results was the demonstration of the attainment of self-sustaining high temperature (2000° F.) incandescent radiant operation in the silicon carbide tube 12. The radiant condition was caused solely by the conduction of heat from the catalytic surface combustion of natural gas and air on the inside surface of the tube and achieved a surface heat flux density of from 15 to 30 MBtu/hr-ft 2 (30 to 61 W/in 2 ). This is comparable to the flux density of existing ceramic electric resistance units, which produce about 22 to 37 MBtu/hr-ft 2 (45 to 75 W/in 2 ) in furnaces rated at 2200° F. The heat flux density of our catalytic tube in fact exceeded that of existing gas-fired radiant tubes, which produce typical flux densities of 6 to 8 MBtu/hr-ft 2 (12 to 16 W/in 2 ).
Secondly, the gas temperature rise through the tube 12 was only about 200° F. This is desirable because it indicates that heterogeneous (i.e., catalytic surface) combustion dominated over homogeneous (conventional flame-type) combustion. The outlet temperature of about 1200° F. would have been much higher (probably closer to the 2000° F. wall temperature) if the bulk gases had been reacting. Instead the fuel that was consumed was burned on the catalytic surface. This translates into lower NO x emissions (due to the lower combustion temperature) and lower pressure drop across the tube (i.e., <0.5 inches w.c., due to the absence of a flame front).
Thirdly, the combustion efficiency, that is, the percentage of the fuel that was burned, was about fifty percent, which is a higher percentage than had been predicted by computer models. It is significant to note that the above-described heat flux densities were achieved without heat recuperation and at this relatively low combustion efficiency.
FIG. 2 depicts application of the above-described catalytic tubes 12 in a 120 kW (400 MBtu/hr) standard box-type furnace 70 having a five foot long working space or chamber 71. The tubes 12--12 are positioned vertically against the side walls of the working chamber 71 and are connected between an upper reactant inlet manifold 72 and a lower exhaust manifold 73. Access is provided to the chamber by a door 74 which is raised and lowered by a wheel-actuated lift mechanism 76. In this exemplary box furnace, twenty tubes approximately two feet long and 1.5 inches in diameter and spaced evenly apart on six inch centers would each release heat at the rate of 20 MBtu/hr (at a heat flux density of about 25 MBtu/hr-ft 2 ), which would generate the required furnace power of about 120 kW (400 MBtu/hr). Quite obviously, these figures are given by way of example only and the size of the furnace, number of tubes, etc., will be varied in accordance with the particular power requirements for a given application.
As mentioned above, the excellent heat flux density has been achieved for radiant tube 12 at relatively low combustion efficiencies of about fifty percent. Referring again to FIG. 1, in a presently preferred system embodiment, our radiant tuve includes (1) downstream catalyst coated honeycomb monoliths 31a and 51a which consume the fuel that remains after the reactants pass over the tube surface, (2) heating elements or regenerators 29 and 49 which recover heat in the exit gas and (3) a dual inlet/exhaust unit construction which permits recycling preheating operation. As described below, the overall construction and operation of system 10 including the honeycombs, the regenerators and the recycling feature, permits catalytic-tube heating system combustion efficiency of nearly one hundred percent and seventy-eighty percent thermal efficiency.
In system 10, the reverse-flow cycling system comprises a pair of inlet-exhaust units 21 and 41. The inlet/exhaust units 21 and 41 include tubes or conduits 22 and 42, respectively, which communicate with the catalytic combustor 12 at opposite ends of the tube 14. In the illustrated embodiment, the tubes 22, 14, 42 can be conveniently formed as a unitary, continuous tube or, alternatively, can be formed as separate tubes which are joined.
Considering now the construction and operation of inlet/exhaust unit 21, tube 22 includes an air inlet 23 and an exhaust 26. Inlet 23 is connected to a source of pressurized air (not shown). Air flow into the main tube 22 and exhaust flow from the main tube are controlled, respectively, by valves 24 and 27. The main conduit 22 also includes a regenerator unit 28 comprising the regenerators or heating elements 29 of a suitable temperature-resistant material such as ceramic spheres or pellets which are positioned between the coated and uncoated honeycomb end units 31a and 31b, respectively. As mentioned, the regenerator 28 is heated by hot exhaust gases during one cycle and in turn preheats the incoming air stream during the succeeding, reverse flow cycle. Fuel is added to the inlet air flow by an inlet jet 32 which is adjacent opposed-jet igniter 33 of the left side of furnace 11.
Inlet/exhaust unit 41 is essentially identical to unit 21 and includes a main conduit or tube 42; a pressurized air inlet 43 and an exhaust conduit 46; inlet and exhaust valves 44 and 47; regenerator 48, comprising heating elements 49 and uncoated honeycomb ends 51; and fuel injector 52. A suitable ignition system such as a pilot flame jetting from an igniter at the right side of furnace 11 can be provided for unit 41, in addition to the igniter 33 provided for unit 21. However, ignition normally is required only once during each operation sequence and each operation sequence can be started using unit 21 in its inlet mode and 41 in its exhaust mode. Thus, only the single igniter 33, for unit 21, is required. After start-up, the igniter 33 can be withdrawn from the main flow stream, as indicated by arrow 38.
When the time, Δt, for each combustion cycle is sufficiently long, it may be convenient to use manually-operated valves 24, 27, 44 and 47. Alternatively, and in particular where the cycle time Δt is relatively short, it is convenient to use solenoid-controlled valves and to incorporate a timing circuit, such as that illustrated at 60, for automatically opening and closing the valves 24, 27, 44 and 47 to initiate and terminate each cycle. Each cycle time Δt is predetermined in accordance with factors such as the rate of inlet air flow, the heat capacity/retention of the regenerators 28 and 48 and the operating temperature.
In the simplified timing control circuit 60 shown in the figure, a conventional electronic timer 61 applies control signals over output lines or buses 34 and 54 at intervals Δt to set and reset flip-flops 36 and 56. The flip-flops selectively turn on and off power transistors 37 and 57 to open and close valves 24, 27, 44 and 47. Of course, various ether control circuits using dedicated microprocessors, computers or controller units can be used. Also, depending upon the size of the system 10 and the size of the various inlet and exhaust conduits, it may be desirable to use larger valve means such as gate valves or to use vanes or other types of flow control devices.
Operation of Radiant Tube Heating System 10
During the initial cycle, inlet/exhaust unit 21 is set in the inlet mode and inlet/exhaust unit 41 is in the exhaust mode. These modes are implemented by setting the valves or vanes 24 and 47 open and 27 and 44 closed, either manually, or automatically using control circuit 60. Air flows through the open inlet valve 23, regenerator 28, and past fuel inlet 32 and igniter 33 into the tubular combustion chamber 12. The gaseous combustion products from the combustion chamber then flow through regenerator unit 48 and are exhausted through open exhaust valve 47. At the start of this initial cycle, fuel is added at and ignited by opposed-jet igniter 33, creating a bow flame which forms upstream of the igniter and heats the tubular combustion chamber 12, (i.e., heats the honeycombs 16--16 and the tube 14). When the chamber reaches a desired operating temperature (for example, 1600° F.), fuel is added via inlet jet 32 and the igniter 33 is turned off and retracted from the stream as indicated by arrow 38. The flows of fuel and air are continued for the cycle time, Δt, maintaining the combustion and thereby heating the chamber 11 and the heat sink material therein and heating the second regenerator 48 in the hot exhaust flow.
At the end of this first cycle, at t=Δt, the gas flow through the system 10 is reversed by opening valves 44 and 27 and closing valves 24 and 47 to set the inlet/exhaust unit 41 in the inlet mode and the inlet/exhaust unit 21 in the exhaust mode. During this second, reversed flow cycle, inlet air from the open valve 44 is preheated by the previously heated regenerator unit 48 and passes fuel inlet 52, where fuel is added. Then, the air and fuel mixture enters the tubular combustion chamber 12 and undergoes combustion and the gaseous combustion products flow through the first regenerator unit 28 and are exhausted through the open exhaust valve 27.
During this second cycle, the hot exhaust gases heat the first regenerator unit 28 preparatory to reversing the flow at t=2Δt and starting another cycle. Thus, during each cycle of the two-cycle operation after the first cycle, the previously heated inlet side regenerator preheats the incoming air stream and the exhaust side regenerator is heated by the exhaust gases. These alternating cycles provide a continuous supply of preheated air that ensures a high combustion efficiency, high thermal efficiency operation for the catalytic combustion chamber 12. In short, the construction of the chamber 12 and the two-cycle reverse flow system and operation thereof achieve the four critical objectives of high combustion efficiency, high system thermal efficiency, uniform radiant energy transfer, and low emission levels of combustion products such as NO x .
The foregoing description of the preferred and alternative embodiments of our invention is presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obviously, modifications and variations will be possible to those of usual skill in the art in light of the above teachings. The preferred embodiment was chosen and described in order to best explain the principles of the invention and its practical application and to thereby enable others skilled in the art to best utilize the invention and various embodiments and with various modifications as are suited to the particular use contemplated. It is thus intended that the scope of the invention be defined only by the claims which follow. | A gas-fired radiant tube that employs heterogeneous catalytic combustion, and a high combustion efficiency, low NO x catalytic combustion radiant tube heating system, incorporating the radiant tube, are disclosed. In the system, essentially mirror image, combined inlet/exhaust units containing heat regenerator units are connected at opposite ends of the catalytic combustion tube. Combustion flow is cycled back and forth through the units and the combustion tube so that during any given cycle the hot exhaust gases heat the regenerator in the exhaust side of the flow for preheating the inlet gases during the next, reversed flow cycle and the natural gas fuel is completely oxidized. Thus, the cycled flow completely consumes the fuel and constantly preheats inlet air so that the sytem provides both high combustion efficiency and high thermal efficiency. | 5 |
FIELD OF THE INVENTION
The present invention relates to a hand-held electronic device including a mobile telecommunications device such as a mobile phone or PDA, having loudspeakers mounted therein. The invention also relates to a method of controlling such a device.
BACKGROUND OF THE INVENTION
Recent developments in hand-held electronic devices such as mobile phones have resulted in improvements in the quality of sound reproduction, thereby enabling music to be played though such devices. Conventionally, it is common for the sound to be reproduced through headphones and an internally mounted loudspeaker is used only to produce general sounds such as ring-tones and other individual tones to signify key-presses. However, these devices are increasingly being provided with internal loudspeakers that can be used to project sounds/music directly from the device towards the listener in a hands-free format in addition to ring-tones and other more general sounds relating to the operation of the device. It will be appreciated that, if an internal loudspeaker is used to enable a user to listen to music, the quality of sound reproduction becomes an important consideration.
To maximise quality, it is desirable to be able to reproduce stereo effect sound to give the listener a greater 3-D or ‘spatial’ effect of the projected sound. However, producing stereo sound from a device as small as a mobile phone presents a number of problems. Firstly, two separate loudspeakers are required and, when the device is orientated in a position of use, the loudspeakers must be spaced horizontally from each other by a minimum distance so that sound is directed to either side of the listener to effectively reproduce a stereo effect. As mobile telecommunication devices are relatively small, obtaining the minimum horizontal spacing between the loudspeakers is difficult. However, if suitable digital processing is used, it is possible to spatially enhance the sound to expand the sound stage dramatically and produce a stereo effect.
The requirement for a minimum horizontal spacing between loudspeakers so as to direct sound towards either side of a listener leads to a problem when the device is intended for use in both an upright or ‘portrait’ position and also in a sideways or ‘landscape’ position. These two positions are illustrated by schematic front views of a prior art mobile device 10 comprising a mobile phone, shown in FIGS. 1A and 1B . When the phone 10 is being used, it is intended that it will be placed so as to face the listener in one of these positions. The ‘landscape’ position may be preferable, for example, when the user is also viewing information displayed on the screen in a landscape orientation, at the same time as listening to sound as the screen may be rectangular, as opposed to square in shape and the information or picture displayed may be viewed more easily in a landscape orientation. It can be seen that the phone 10 is rotated through an angle of 90 degrees between these two positions. The mobile phone 10 , shown in the portrait position in FIG. 1A , has a left loudspeaker 12 and a right loudspeaker 14 , separated from each other by a horizontal spacing H p which is sufficient to enable spatial enhancement and reproduction of stereo sound. However, the mobile phone 10 is shown rotated clockwise by 90 degrees (see arrow A) into the landscape position in FIG. 1B and the loudspeaker 12 is now located directly above the loudspeaker 14 . This means that the horizontal spacing of the two loudspeakers 12 , 14 in the landscape position H 1 , is reduced to zero, so that they provide no spatial effect, thereby rendering production of stereo sound impossible. An example of a device of this type is known from U.S. Pat. No. 6,760,447 (P. A. Nelson et al).
One solution to the problem referred to above is to provide a first pair of loudspeakers spaced from each other in the horizontal direction to provide stereo sound when the phone is in the portrait position, and a second pair of loudspeakers displaced from each other in a vertical direction perpendicular to the direction of displacement of the first pair of loudspeakers such that, when the phone is rotated into the landscape position, the second pair of loudspeakers are horizontally displaced from each other and are thereby able to produce stereo sound.
However, this prior art solution suffers from the drawback that two pairs of loudspeakers are required in the mobile phone, which in turn leads to increased production costs and an increase in the size of the device. An alternative solution could be to provide three loudspeakers in an ‘L’ formation to make up the two ‘pairs’ of loudspeakers in which one speaker would be used when the device is in the portrait position and also when the device is in the landscape position. However, this arrangement would also suffer the drawback that three loudspeakers would be required, again, leading to increased production costs and an increase in the size of the device.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a mobile device that substantially alleviates or overcomes the problems mentioned above.
Accordingly, the present invention provides a hand-held electronic device configured to reproduce stereo effect sound in both a first and a second orientation of the device perpendicular to each other, comprising a single pair of loudspeakers spaced from each other in two directions perpendicular to each other such that one of the directions always lies in a horizontal plane irrespective of whether the device is in its first or second orientation.
As there is a horizontal separation of the loudspeakers irrespective of whether the device is in the first or second orientation, sound is directed towards both sides of the listener and the spatial effect is maintained.
The mobile device is intended for use in a first upright or portrait position, and a second sideways or landscape position, the mobile device being rotated through 90 degrees between said first and second positions. The spacing between the loudspeakers in a first direction may be equal to the spacing between the loudspeakers in a second perpendicular direction. Alternatively, the spacing between the loudspeakers in a first direction may be less than or greater than the spacing between the loudspeakers in a second perpendicular direction.
The device may further include a controller configured to automatically change a digital processing algorithm used to produce the stereo effect sound to compensate for the difference in spacing between the loudspeakers in the first and second directions, when the device is rotated between the first and second positions.
The control unit may also be configured to swap the stereo sound signals fed to the loudspeakers when the orientation of the mobile device is changed between the first and second positions if, when changing the orientation of the mobile device between the first and second positions, the loudspeakers exchange places as the left-most speaker and right-most speaker respectively.
The hand-held electronic device may include a housing, the loudspeakers being disposed so as to face outwardly towards a user of the device from the housing. Alternatively, the housing may have a peripheral edge face, and at least one, or both of the loudspeakers may be disposed on the peripheral edge face of the housing. In one embodiment, the loudspeakers may be orientated so as to at least partially direct sound away from each other.
The present invention also provides a mobile telecommunications device for producing stereo effect sound in both a first and a second orientation of the device perpendicular to each other, comprising a single pair of loudspeakers spaced from each other in two directions perpendicular to each other such that one of the directions always lies in a horizontal plane irrespective of whether the device is in its first or second orientation.
The present invention also provides hand-held electronic device intended for use in two different orientations substantially at right angles to each other and configured to reproduce stereo effect sound in both said orientations, the device comprising a single pair of loudspeakers which, when the device is being used in either orientation, are spaced from each other in a direction which is substantially parallel to a fixed imaginary line of reference extending through the user's ears
According to another aspect of the invention, there is provided a method of controlling a hand-held electronic device configured to reproduce stereo effect sound in both a first and a second orientation of the device perpendicular to each other, comprising a single pair of loudspeakers spaced from each other in two directions perpendicular to each other such that one of the directions always lies in a horizontal plane irrespective of whether the device is in its first or second orientation, the method including the step of altering a digital processing algorithm to compensate for the difference in spacing between the loudspeakers when the device is rotated between the first and second orientations.
According to yet another aspect of the invention, there is provided a method of controlling a hand-held electronic device configured to reproduce stereo effect sound in both a first and a second orientation of the device perpendicular to each other, comprising a single pair of loudspeakers spaced from each other in two directions perpendicular to each other such that one of the directions always lies in a horizontal plane irrespective of whether the device is in its first or second orientation, the method including the step of swapping the stereo sound signals fed to the loudspeakers when the orientation of the mobile device is changed between the first and second orientations if, when changing the orientation of the mobile device between the first and second orientations, the loudspeakers exchange places as the left-most speaker and right-most speaker respectively.
Embodiments of the present invention will now be described, with reference to FIGS. 2A-5 of the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a schematic view of a prior art hand-held electronic device in an upright, portrait position;
FIG. 1B is the prior art device of FIG. 1A in a sideways, landscape position;
FIG. 2A is a schematic view of a hand-held electronic device according to a first embodiment of the invention in an upright, portrait position;
FIG. 2B is the device of FIG. 2A in a sideways, landscape position;
FIG. 3A is a schematic view of a hand-held electronic device according to a second embodiment of the invention in an upright, portrait position;
FIG. 3B is the device of FIG. 3A in a sideways, landscape position;
FIG. 4A is a schematic view of a hand-held electronic device according to a third embodiment of the invention in an upright, portrait position;
FIG. 4B is the device of FIG. 4A in a sideways, landscape position; and
FIG. 5 is a schematic view of a hand-held electronic device according to a fourth embodiment of the invention.
DETAILED DESCRIPTION
Referring now to FIGS. 2A and 2B , there is shown a first embodiment of a hand-held electronic device according to the present invention comprising a mobile telephone 100 having a housing 101 including a front face 106 and first and second loudspeakers 102 , 104 mounted in the housing 101 so as to direct sound through apertures (not shown) in the front face 106 . The front face 106 includes a display screen 108 , the loudspeakers 102 , 104 being disposed one either side of the display screen 108 . The phone 100 is shown in the portrait position in FIG. 2A and, as a user views the front face 106 of the phone 100 , the first loudspeaker 102 is on the left and the second loudspeaker 104 is on the right so as to direct sound towards the left and right hand sides of a listener, respectively. In this portrait position, the first and second loudspeakers 102 , 104 are spaced from one another in the horizontal direction by a distance D 1 shown in FIG. 2A . This spacing D 1 between the loudspeakers is sufficient to enable the reproduction of stereo effect sound when the phone 100 is in the portrait position. However, it can be seen from FIGS. 2A and 2B that the first and second loudspeakers 102 , 104 are also diagonally disposed from one another which means that they are spaced from each other in a vertical direction D 2 . Although this vertical spacing D 2 has no discernable effect on the reproduction of stereo sound when the phone 100 is in the portrait position, when it is rotated by 90 degrees clockwise into the landscape position shown in FIG. 2B , the spacing D 2 becomes a horizontal spacing of the first and second loudspeakers 102 , 104 and so the phone 100 is still capable of reproducing stereo effect sound.
When stereo sound is produced, whether by conventional two-channel signals sent to two separate loudspeakers or by spatially digitally-processed signals sent to two separate loudspeakers, the electronic sound signals sent to each loudspeaker are not the same but are speaker-specific. When the phone 100 is rotated through 90 degrees clockwise (shown by arrow X) from the portrait position in FIG. 2A to the landscape position shown in FIG. 2B , from the user's view point, the first loudspeaker 102 remains on the left-hand side and the second loudspeaker 104 remains on the right-hand side. Therefore, the signals transmitted to each loudspeaker 102 , 104 by a signal processing unit do not need to be swapped over for the phone 100 to continue to reproduce stereo effect sound.
A second embodiment of the present invention is shown in FIGS. 3A and 3B comprising a mobile telephone 200 having a housing 201 and first and second loudspeakers 202 , 204 mounted on a front face 206 of the housing 201 . The front face 206 includes a display screen 208 and the loudspeakers 202 , 204 are disposed one either side of the display screen 208 . The phone 200 is shown in the portrait position in FIG. 3A and, as a user views the front face 206 of the phone 200 , the first loudspeaker 202 is on the left-hand side and the second loudspeaker 204 is on the right-hand side so as to direct sound towards either side of a listener facing the device. In this portrait position, the first and second loudspeakers 202 , 204 are spaced from one another in the horizontal direction by a distance D 3 which is sufficient for the device to be able to produce stereo effect sound. As with the first embodiment 100 described above, the first and second loudspeakers 202 , 204 are diagonally disposed from one another and so are spaced from each other in a vertical direction (shown as D 4 in FIGS. 3A and 3B ) perpendicular to the horizontal direction D 3 . Therefore, when the phone 200 is rotated by 90 degrees clockwise (shown by arrow Y) to the landscape position shown in FIG. 3B , the spacing D 4 becomes the horizontal spacing of the loudspeakers 202 , 204 , thus ensuring that the phone is capable of reproducing stereo effect sound.
It can be seen that in this second embodiment, the distance D 4 between the first and second loudspeakers 202 , 204 in the vertical direction when the phone 200 is in the portrait position, is greater than the distance D 3 in the horizontal direction. The electronic sound signals transmitted to each loudspeaker to produce stereo effect sound are calculated by a digital signal-processing audio algorithm in dependence upon a number of parameters, one of which is the spacing between the two loudspeakers. Therefore, because the horizontal spacing between the first and second loudspeakers 202 , 204 differs between when the phone 201 is in the portrait position relative to the landscape position, the digital audio algorithm parameter must be changed to take account of the change in loudspeaker spacing so that the electronic signals transmitted to each loudspeaker 202 , 204 are correct depending on whether the phone is in the portrait or landscape position. It has been found that a change in distance between the loudspeakers 202 , 204 by a factor of up to 1.5 without changing the parameter of the digital audio algorithm to alter the electronic sound signals, has a relatively small detrimental effect on the quality of the stereo sound reproduction. For example, if D 3 was 4 cm, and D 4 was 6 cm, the effect on the sound quality would be negligible. However, if the factor is greater than 2, then a more serious deterioration in stereo sound reproduction is noticed and the digital algorithm parameter must be altered to take account of this when the orientation of the phone is changed. For example, if D 3 is 4 cm and D 4 is 8 cm, then the phone 200 would include a controller configured to detect the orientation of the phone 200 and to cause the digital audio algorithm to alter the electronic sound signals transmitted to the loudspeakers 202 , 204 to take account of the difference in horizontal distance between the loudspeakers 202 , 204 in the portrait position and the landscape position. As mentioned above, a user may wish to view information displayed on the screen 208 in a landscape orientation, in which case, the phone would have a control function to allow the user to manually select the desired screen orientation. In this case, the controller would not need a means to detect which orientation the phone is to be used in, as instead, the information could be taken from the manually operated control function used to display information on the screen in the correct orientation and, from this, the controller would select the correct parameter for the digital audio algorithm appropriate to the horizontal spacing of the loudspeakers.
A third embodiment of the present invention is shown in FIGS. 4A and 4B comprising a mobile telephone 300 having a housing 301 and first and second loudspeakers 302 , 304 mounted on a front face 306 of the housing 301 . The front face 306 includes a display screen 308 and the loudspeakers 302 , 304 are disposed one either side of the display screen 308 . The phone 300 is shown in the portrait position in FIG. 4A and, as a user views the front face 306 of the phone 300 , the first loudspeaker 302 is on the left-hand side and the second loudspeaker 304 is on the right-hand side. As with the first embodiment shown in FIGS. 2A and 2B , the first and second loudspeakers 302 , 304 are spaced from each other in the horizontal direction by a first distance D 5 , and are spaced from each other in the vertical direction by a second distance D 6 (see FIG. 4A ). In this embodiment, the position of the loudspeakers 302 , 304 is such that in the portrait position, the first loudspeaker 302 is on the left and the second loudspeaker 304 is on the right. However, when the phone 300 is rotated by 90 degrees clockwise into the landscape position as shown by arrow and FIG. 4B , the first loudspeaker 302 becomes the right loudspeaker and the second loudspeaker 304 becomes the left loudspeaker. Likewise, this loudspeaker reversal would also occur if the first and second embodiments of the invention described above and illustrated in FIGS. 2A , 2 B, 3 A, and 3 B were rotated anti-clockwise into the landscape position. As mentioned above, to reproduce stereo effect sound, the electronic signals sent to each loudspeaker 302 , 304 are not identical, but are specific to whether the loudspeaker is the right or the left loudspeaker. Therefore, to allow for the swapping of sides of the loudspeakers 302 , 304 in moving between the portrait and the landscape positions, the mobile phone 300 includes a controller (not shown) to automatically detect which position the phone 300 is in and transmit the appropriate electronic signals to the correct left/right loudspeaker accordingly.
It is envisaged within the scope of the invention that a further, unillustrated embodiment may include controller functions of the second embodiment in FIGS. 3A and 3B and also of the third embodiment in FIGS. 4A and 4B . This would allow the device to be capable of detecting the horizontal spacing between the loudspeakers in the portrait and landscape positions and to alter the electronic stereo sound signals transmitted to each loudspeaker accordingly if the horizontal spacing changes, and also to detect which loudspeaker was the left loudspeaker and which was the right loudspeaker for whichever orientation the device was positioned in to ensure that each loudspeaker receives the correct electronic stereo sound signal to reproduce the desired stereo effect sound.
The various embodiments described above have all been shown with the loudspeakers positioned on one single face of the device. However, further embodiment 400 , illustrated in FIG. 5 , shows how the loudspeakers could be arranged in an alternative configuration. This fourth embodiment 400 comprises a housing 401 having a front face 406 with a display screen 408 , a rear face 410 and a peripheral edge face 412 . First and second loudspeakers 402 , 404 are disposed at diagonally opposed corners of the device 400 , with the first loudspeaker 402 extending over one corner of the front face 406 and the peripheral edge face 412 at the top and one side of the device, and the second loudspeaker 404 extending over the diagonally opposite corner of the front face 406 and the peripheral edge face 412 at the bottom and opposite side so that sound is directed towards the user of the device from both the front and side of the device. The device would operate as described above with reference to the first to third embodiments of the invention, except that the sound projection from the first and second loudspeakers 402 , 404 would be improved due to the outward projection of sound that could be achieved over flat face-mounted speakers.
It is also envisaged that the speakers could be located so as to face wholly outwardly from either side of the housing rather that having at least a portion facing towards the user. In such a configuration, the design tuning of the device would be critical to maximise performance.
Many modifications and variations of the invention falling within the terms of the appended claims will be apparent to those skilled in the art and the foregoing description should be regarded as a description of the preferred embodiments only. | A hand-held electronic device for producing stereo effect sound in both a first and a second orientation of the device. The first and second directions are perpendicular to each other. The device comprises a pair of loudspeakers spaced from each other in two directions perpendicular to each other. One direction always lies in a horizontal plane irrespective of whether the device is in its first or second orientation. | 6 |
[0001] This application claims priority from U.S. Provisional patent application Ser. No. 60/ 514,946 filed Oct. 28, 2003.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a method for delignifying softwood or hardwood pulp in a slurry at low consistency using a reaction device and oxygen.
[0003] Oxygen delignification of cellulosic material is generally practiced at medium consistency (8 to 16%) a region where it has been determined makes it both relatively easy to operate and economical. In such operations partially delignified pulp is reacted with oxygen in the presence of alkali (pH>11) using high shear mixers and pressurized upflow reactors with retention times of 20 to 60 minutes at pressure in excess of 90 psi and temperatures as high as 110° C. The high shear mixers facilitate the contacting of the pulp slurry with the oxygen containing gas in a very turbulent state lasting a few seconds prior to entering the pressurized vessels.
[0004] Using such equipment in single and two-stage configurations have resulted in reported delignification of up to 45%. However, many of such systems perform below 40% kappa reduction due to less than optimal contacting of oxygen with the pulp. In addition, implementation of medium consistency oxygen delignification require high capital expenditures for high shear mixers, medium consistency pumps and large contact towers and have thus far excluded many mills from economically modifying their processes and taking advantage of this technology. Low consistency oxygen delignification has not been practiced commercially due to cost of chemicals and steam that would be required.
[0005] Oxygen delignification systems have traditionally been located after the brownstock washers on a fiber line where the slurry is relatively cold and have been stripped of all caustic thus requiring the addition of the full complement of steam and caustic. As a result of the high capital cost, energy costs and anticipated higher cost of chemicals, low consistency, or below 8% cellulosic material, oxygen delignification has not been practiced commercially.
SUMMARY OF THE INVENTION
[0006] The present invention provides a method for delignifying softwood or hard wood pulp in a slurry at low consistency by adding to the pulp slurry oxygen and adding this pulp slurry reaction mixture to a reaction system comprising an efficient mixer and contact tank. Preferably the pulp is removed from the brownstock processing section (between the blow tank and the bleach section of the papermaking system. The reaction system is physically located after the knotters and before the brown stock washers to make more effective use of the residual alkali and heat content in the incoming black liquor. The physical location of the reaction system can be at a convenient position along the papermaking system; only the pulp slurry that is removed is “fixed” in that it is removed from the point between the knotters and the brown stock washers.
[0007] For purposes of the present invention, “low consistency” is defined as that pulp containing less than 8% by weight of cellulosic material.
[0008] In practicing the methods of the present invention, the reaction system may also be physically located and the pulp slurry drawn from the section of the fiber line after the digester and before the brown stock washers, or in between any two stages of a multi-stage brownstock washing step.
[0009] The hot pulp slurry is taken from the knotters with the black liquor still present. The black liquor results from cooking pulpwood in an aqueous solution in the sulfate or kraft papermaking process. Steam may be added to heat the slurry as well as caustic which can be used to adjust the pH. Oxygen is injected into the mixture which is then sent to the gas liquid mixer. The pulp slurry containing the oxygen is mixed at conditions of temperature and pressure whereby the oxygen begins to react with the lignin to effect delignification. This reaction mixture is then sent from the mixer to a retention tank which is also capable of being kept at pressure, where the delignification reaction will continue further. The reaction products are then sent into a blow tank or a gas-liquid separator where reaction gases and unused oxygen gas is disengaged or removed from the liquid product and scrubbed and either vented to the atmosphere or recycled.
[0010] The invention may be implemented as a retrofit in existing mills as well as new ones at relatively low capital cost. The placement of the system takes advantage of the residual caustic and heat that will be present in the slurry as it leaves the knotters. Furthermore a low consistency oxygen delignification reaction will be easier to control compared to operations at medium and high consistencies of pulp. Accordingly low consistency oxygen delignification before the brown stock washers of a fiber line is achieved.
[0011] The reactor assembly consists of a controlled cavitation device or other efficient mixing device, coupled with a residence tank.
[0012] The heat and alkali requirements for the delignification reaction will be obtained primarily from the residual alkali and heat content in the incoming black liquor and an oxygen containing gas.
[0013] The amount of oxygen present can be an excess so as to react with some of the organic acids in the black liquor to reduce the heat value of the black liquor, and to react with sulfur compounds in the black liquor to reduce or eliminate the potential for total reduced sulfur (TRS) emissions.
[0014] A further advantage of the present invention is that un-oxidized white liquor is employed as the source of needed alkali. Additionally the excess oxygen is employed to oxidize some of the sulfur compounds in the white liquor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The FIGURE is a schematic representation of an oxygen delignification process according to the practice of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] The present invention provides for the low consistency oxygen delignification of pulp and comprises the following steps:
[0017] Taking pulp slurry at consistencies between 2 to 8% from the fiber line, at an appropriate location;
[0018] The pulp slurry drawn from the fiber line may be removed between the knotters and the brown stock washers, or before the brown stock washers and after the digester, or in between any two stages of a multi-stage brownstock washing step.
[0019] When necessary, adding a small amount of caustic to bring the slurry pH to at least 11 to 12;
[0020] Adding steam (when needed) to bring slurry temperature to between 85° C. to 120° C.;
[0021] Introducing the slurry and an oxygen containing gas into a high efficiency mixer for intense mixing under pressure of between 20 and 160 psig for up to 2 minutes;
[0022] Sending the slurry and oxygen mixture to a holding tank and maintaining it under pressure of 20 to 160 psig for 5 to 30 minutes;
[0023] Sending the reaction mixture to a disengagement tank where the reaction gases are separated from the slurry and sent for treatment and disposal; and
[0024] Sending the slurry to the next stage in the bleach line of the papermaking process, which could be the screens or brown stock washers.
[0025] In the embodiment shown in FIG. 1 , pulp slurry from the knotters is contacted with oxygen in the presence of caustic, temperature and allowed a short residence time in a retention tank for the oxygen to react with and delignify the pulp. The oxygen also reacts with the organic solid in the black liquor resulting in a reduction of the heat value of the black liquor going to the recovery boiler. Additional reactions take place between the oxygen and sulfur compounds in the liquor, thus reducing or eliminating potential sources of total reduced sulfur (TRS) emissions by the pulp mill.
[0026] In the process, pulp slurry from the knotters with the black liquor still present and at a consistency of between 2 to 8% is transferred by a pump 30 through pipelines 10 and 40 to a steam mixer 50 . Caustic, if needed may be added to the pulp slurry through side pipe 20 to maintain the pH of the pulp slurry between 11 and 12. At the steam mixer, steam is added to the pulp slurry through pipe line 130 to bring the temperature of the slurry to between 90 and 110° C. before it flows into the efficient mixing device which could be a cavitation type reactor 70 through line 60 . Oxygen containing gas is introduced through a side inlet 140 and enters the efficient mixing device with the pulp slurry stream.
[0027] The pulp slurry and the oxygen containing gas are brought into intimate contact by the shearing and cavitation and mechanical forces generated as the rotor rotates at a high speed in the mixing device 70 . The contacting is performed under suitable conditions of temperature and pressure whereby the oxygen begins to react with the lignin under caustic conditions to effect delignification. The reaction mixture proceeds through pipe line 80 into a retention tank 90 where under conditions of temperature, pressure and time the delignification reaction is continued further.
[0028] In order for the reaction to proceed as mentioned above, an oxygen containing gas must be used. Preferably oxygen with a minimum purity of 93% is employed. The preferred total reaction pressure should be not less than 80 psig and more preferably above 90 psig. The preferred minimum reaction temperature is 90° C. but could be as high as 110° C.
[0029] The residence time of the reaction mixture in the retention tank is not less than 10 minutes but preferably up to 30 minutes. The reaction mixture is withdrawn through outlet 100 into a blow tank or gas-liquid separator 110 where reaction gases and unused oxygen gas disengages from the liquid product and is scrubbed and vented. The pulp slurry is withdrawn through line 120 and sent to the washing stage of the bleach line of the pulp and papermaking process.
[0030] By practicing the methods of the present invention, bleaching can be done with much less capital, specifically by not having to build, own, operate and maintain separate pressure towers for traditional oxygen delignification. Un-oxidized white liquor can be used as the source of caustic as the oxidation of the white liquor also takes place in the mixer. Also, the exothermic heat of reaction of oxidation of white liquor raises the temperature of the pulp resulting in steam savings for oxygen delignification and most of the oxygen delignification reactions can be done at the existing pulp temperature.
[0031] Oxygen delignification before the brown stock washers lowers the BTU value of the black liquor allowing for increased capacity of steam limited recovery boilers. Additionally, less oxidized white liquor will be needed in this sequence than traditional two stage oxygen delignification thus taking the load off the lime kiln and other white liquor systems.
[0032] The black liquor produced will have a lower viscosity because of the reaction of the oxygen with the Na 2 S and a portion of the dissolved lignin allowing for a higher percentage solids firing in the recovery boiler. Methanol and other alcohols present in the black liquor before the brown stock washers will react to form a reducing environment in the pulp. With the availability of hydrogen limited, the side reactions that hurt pulp strength will also be limited. Indeed pulp strength may increase.
[0033] The following is an example of a practice of the invention in accordance with the embodiment illustrated in FIG. 1 . In this example a side stream of softwood slurry at a consistency of 2.5% and containing residual black liquor was withdrawn with a Gould's pump 30 at a flow rate of 50 gallons per minute (gpm) through a side pipe 10 on the stock line going from the knotters to the first brown stock (BS) washers. The pH of the slurry was above 11.5 and so no additional caustic was added. Slurry temperature was 87° C. The slurry was heated to 90° C. adding low-pressure steam through pipe 130 and mixed into the slurry with the steam mixer 50 . Pure oxygen was added to the slurry through a side pipe 140 at a rate of 60 pounds per hour before it entered a high efficiency gas-liquid mixer, in this case a controlled cavitation reactor 70 . The slurry and gas were mixed for a few seconds at about 90 pounds per square inch (psi) in the reactor 70 , the stock was transferred into a retention tank 90 and kept for 10 minutes and was finally returned to the bleach line just before the first BS washer. The pulp Kappa # is the amount of lignin in the pulp sample. Samples were taken from the exit slurry stream for analysis. The following results were obtained:
TABLE 1 Inlet Outlet % Reduction Pulp Kappa # 25.8 16.5 37 Na 2 S, mg/kg 21000 <200 almost solids (non detect) 100 Dissolved Lignin, 32.1 29.1 9.3 As % solids
[0034] Comparatively, for conventional single stage oxygen delignification systems operating under similar conditions of temperature and pressure on a 10% consistency pulp, residence times of 40 minutes and higher will be required to achieve the 37% delignification.
[0035] While this invention has been described with respect to particular embodiments thereof, it is apparent that numerous other forms and modifications of this invention will be obvious to those skilled in the art. The appended claims and this invention generally should be construed to cover all such obvious forms and modifications which are within the true spirit and scope of the present invention.
[0036] Having thus described the invention, | The present invention provides for a method for delignifying softwood or hardwood pulp in a fiber line of a pulp and papermaking system having a slurry at low consistency by adding to the pulp slurry oxygen and adding this pulp slurry reaction mixture to a reaction system comprising an efficient mixer and contact tank. The reaction system is preferably physically located after the knotters and before the brown stock washers to make more effective use the residual alkali and heat content in the incoming black liquor. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of the U.S. national stage designation of International Application PCT/EP01/00450 filed Jan. 17, 2001, the entire content of which is expressly incorporated herein by reference thereto.
TECHNICAL FIELD
[0002] The present invention relates to a valve arrangement for providing clinical nutrition, a flow set comprising the valve arrangement, a method of production of the valve arrangement, use of the valve arrangement in providing nutrition to a patient and a method of treatment of a patient that comprises administering an effective amount of a composition via the valve arrangement.
BACKGROUND ART
[0003] Systems for administration of fluids to a patient are widely known. The manner of propelling the fluid to the patent may be by gravitation, by means of pressure applied on a deformable container, or by means of a pump. In pump-operated administration systems, the pump must be capable of administering the fluid in a controlled, continuous manner.
[0004] Pumps are employed to meet the need for a high degree of accuracy in the administration of fluids, to protect the patient and to maximize the effectiveness of medication.
[0005] WO98/46293 discloses the administration of two fluids to a patient. According to this document, a flow set is described which enables sequential administration of two fluids from a pair of containers to a patient. The flow set has a pair of valve assemblies each in communication with a container. Each valve assembly has a chamber; an inlet port sealed with a first one-way valve allowing flow of fluid through it only into the chamber; an outlet port being sealed with a second one-way valve allowing flow of fluid through it only out of the chamber; and a pump port located between the one-way valves. Inlet tubes connect a container to the inlet ports of each valve assembly. A connecting tube connects the pump ports of the valve assemblies to a pump. Outlet tubes are connected to the outlet port of each valve assembly for delivery of the two fluids to a patient. By reversing the pumping direction of the pump, fluid can be sequentially drawn from one container or the other. Generally, a sensor is associated with the pump for sensing when the containers are empty so that when no fluid passes the sensor the pump is switched off and an alarm sounds to alert an operator to the fact that more fluid is required.
[0006] This arrangement works well, but it has been found that it suffers from the problem that air entrained in the fluid can be released from solution and sensed by the sensor. This can result in activation of the alarm and switching off of the pump even when more fluid is not required. This is inefficient. Indeed, when the alarm sounds, it generally indicates a) the container is empty and more fluid is required or b) feeding is finished and no more fluid is necessary for this feeding. Thus, when entrained air falsely trips the alarm (often referred to as a nuisance alarm), a nurse may either a) believe that she must renew the fluid supply as more fluid is required or b) falsely believe feeding is finished and no more fluid is required or c) have the experience and sense to check the fluid supply, realize it was only a nuisance alarm and re-start the pump with the same fluid supply (preferably shaking to remove any air bubbles).
[0007] Therefore, a need exists for a valve assembly which achieves a good flow and which can be used in the efficient administration of two fluids to a patient, which is safe, relatively simple, easy to use, and requires a single pump. Furthermore, there is a need for a solution to the problem of unnecessary switching off of the pump and activation of the alarm.
[0008] The present invention addresses and resolves the problems of the art.
SUMMARY OF THE INVENTION
[0009] Remarkably, it has now been found that if a critical distance is maintained between the pump port and the inlet valve more efficiency can be achieved and unnecessary switching off of the pump and activation of alarms can be avoided.
[0010] Consequently, in a first aspect, the present invention provides a valve arrangement having a chamber and three ports which include an inlet port sealed with a first one-way valve allowing flow of fluid through it only into the chamber, an outlet port sealed with a second one-way valve allowing flow of fluid through it only out of the chamber and a pump port located between the one-way valves, wherein the first one-way valve is not directly adjacent the pump port.
[0011] In a second aspect the invention provides a flow set for the sequential administration of two fluids from a pair of containers to a patient which comprises two valve arrangements according to an embodiment of the invention; a pair of inlet tubes for connecting containers to the inlet port of each valve arrangement; connecting tubes for connecting a pump to the pump ports; and a pair of outlet tubes for connecting the outlet of each valve arrangement for the delivery of two fluids to a patient.
[0012] In a third aspect the invention provides a method of production of the valve arrangement which comprises making a chamber, making three ports including an inlet port, an outlet port and a pump port, fixing a first one way valve adjacent the inlet port and not directly adjacent the pump port for allowing fluid only into the chamber and fixing a second one-way valve adjacent the outlet port for allowing fluid only out of the chamber.
[0013] In a forth aspect the invention provides use of a valve arrangement according to an embodiment of the invention for providing nutrition to a patient.
[0014] In a fifth aspect the invention provides a method of treatment of a patient that comprises administering an effective amount of a fluid via a valve arrangement according to an embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0015] Additional features and advantages of the present invention are described in, and will be apparent from, the description of the presently preferred embodiments which are set out below with reference to the drawings in which:
[0016] [0016]FIG. 1 shows a flow set having a known valve assembly;
[0017] [0017]FIG. 2 shows a flow set having a valve assembly according to an embodiment of the invention; and
[0018] [0018]FIG. 3 shows a valve arrangement in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] A valve arrangement according to an embodiment of the invention provides the advantage of permitting simple and safe switching between fluids from two containers to which a flow set is connected. Fluid may be drawn from one container, into an embodiment of the valve assembly and out through its pump port to a second embodiment of a valve assembly through its pump port. Fluid may flow out of the outlet port of the second valve assembly to a patient. By merely reversing the pumping direction a fluid may be drawn from a second container into the second embodiment of the valve assembly and hence to a patient in a manner mirroring the first. No disconnection of tubing is required and no manual adjustment of valves is required.
[0020] Another advantage of the present invention is that the flow of fluid from the outlet port of the valve arrangement can be accurately controlled. In view of the fact that the pump port is not directly adjacent the inlet one-way valve, any air released from solution does not enter the pump port. Consequently, air is not sensed by a sensor associated with the pump and unnecessary triggering of alarms and switching off of the pump can be avoided. Known valve arrangements have suffered from the problem that they have been prone to developing an air trap here and this has inhibited their efficiency.
[0021] Yet another advantage of the present invention is that it provides an arrangement that is easier and less expensive to make than known arrangements. Standard commercially available parts eg valves can be employed. In addition, a simple construction method can be carried out from available parts comprising a simple housing and membranes and this increased simplicity adds to the speed at which production can be achieved. With regard to the fluid flow, two liquids can be administered to a patient with no cross contamination. Advantageously this can be carried out with a single pump to manage two fluids.
[0022] In addition, the switching between fluids may be rapid because no disconnection of tubing or changing of pumps is required. Furthermore, two separate fluids can be managed independently with regard to volume and flow rate. Preferably, these fluids include a nutritional composition for the patient.
[0023] Preferably, an embodiment of a valve arrangement according to the present invention includes a distance of about 20 cm to about 60 cm between the axis of the pump port and the surface of the inlet one-way valve. More preferably the distance is about 30 cm to about 50 cm. Most preferably the distance is about 40 cm.
[0024] Remarkably, it has now been found that these specific distances are critical to the efficiency of the valve arrangement. They are not merely a result of optimization of the known apparatus. Mere optimization would be expected to lead to no distance. In contrast, it has surprisingly been found that the distances help ensure that an air trap does not inhibit the smooth flow of fluid.
[0025] Preferably, the inlet valve has a low cracking pressure and the outlet valve has a high cracking pressure. More preferably, the cracking pressure of the inlet valve is close to and is approximately 0 kPa. More preferably, the cracking pressure of the outlet valve exceeds about 10 kPa. More preferably it exceeds about 15 kPa.
[0026] It has been found that these cracking pressures provide the advantage that, if a pump is disconnected from the valve arrangement fluid is not able to pass through the outlet valve to a patient. Therefore, uncontrolled flow to the patient is prevented.
[0027] Preferably the chamber has an internal diameter of about 1 mm to about 5 mm. More preferably it is about 2 mm to about 4 mm. Most preferably it is about 3 mm. Preferably it is provided by tubing having this internal diameter.
[0028] It has suprisingly been found that these specific internal diameters give rise to the advantage that less dissolved air is present in the chamber compared to known valve arrangements. In the light of this the air does not come out of solution and form an air pocket.
[0029] Preferably, an embodiment of a valve arrangement according to the present invention includes a valve which comprises a flexible membrane which is deformable under pressure in a desired flow direction. Each flexible membrane has perforations through it which open at a selected extent of deformation of the flexible membrane to permit flow. Each valve assembly may be provided with a support associated with each flexible membrane for preventing the flexible membrane from deforming sufficiently in a direction opposite the flow direction for preventing back flow. In accordance with a preferred embodiment the invention the membrane of the inlet valve deforms at a low cracking pressure and the membrane of the outlet valve deforms at a high cracking pressure.
[0030] Preferably, an embodiment of a valve arrangement according to the present invention is obtained by modification of known apparatus. Suitable starting materials are for example: a housing manufactured of metal or plastics material, preferably rigid plastics material including ABS, polycarbonate, PVC, acrylic or MABS; and a valve membrane manufactured of a resilient material including polyurethane, silicon or rubber.
[0031] Preferably, a method of treatment according to the present invention includes the steps of sequentially administering two fluids from a pair of containers to a patient using a pump to propel the fluids and a valve arrangement according to an embodiment of the invention by:
[0032] operating a pump in one pumping direction for pumping fluid from a first container through a pump system, the fluid flowing in a first flow path through an inlet tube connected to the first container to the inlet port of a first valve assembly, out through the pump port of the first valve assembly, in the pump port of the second valve assembly, and through an outlet tube to a patient; and
[0033] reversing the pumping direction of the pump for pumping fluid from the second of the containers in a second flow path through an inlet tube connected to a second container to the inlet port of the second valve assembly, out through the pump port of the second valve assembly and in the pump port of the first valve assembly, and through an outlet tube to a patient.
[0034] Preferably the pumping direction of the pump is reversed automatically in accordance with instructions stored within a control unit associated with the pump. The pumping direction is preferably reversed at least twice.
[0035] A known flow set which may be used to sequentially administer two fluids is illustrated for comparison with the invention in FIG. 1. The flow set 1 is made up of a tubing set comprising a pair of tube branches. Each branch has a drip chamber 2 , 3 , and a valve arrangement 10 , 20 . The valve arrangements are connected together by a connecting tube 30 . A pair of outlet tubes 11 , 21 , one for each branch, is connected to the valve arrangement at one of their ends and they are connected together at their other end by a Y connector 40 . The connecting tube 30 is positioned upstream of Y-connector 40 . An administration tube 41 is connected to the Y connector at one end and its other end is connected to a connector 42 . As is conventional, the connector 42 may be connected to a catheter, an enteral feeding tube, etc. When not in use, the free end of the connector 42 is covered by a cover 43 .
[0036] Each tube branch is made up of a pair of inlet tubes 12 , 22 and a pair of outlet tubes 11 , 21 . One end of each inlet tube 12 , 22 is connectable to a separate fluid container 4 , 5 . The other end of each inlet tube 12 , 22 is connected to an inlet 13 , 23 of a valve arrangement 10 , 20 . Drip chambers 2 , 3 are provided in series with the inlet tubes 12 , 22 . One end of each outlet tube 11 , 21 is connected to the Y-connector 40 . A connecting tube 30 spans between the two valve arrangements 10 , 20 ; connecting to a pump port 14 , 24 of each valve arrangement 10 , 20 . A shaped connecting element 31 is provided in series with the connecting tube 30 .
[0037] Referring now to FIGS. 2 and 3, each valve arrangement 10 , 20 according to an embodiment of the invention comprises a housing 50 formed of three body members; a first body member 51 , a second body member 60 and a third body member 70 .
[0038] The first body member 51 comprises a channel having a chamber 58 at one end. The lower end of the chamber is closed by a base plate 52 which has an opening 53 having an annular rim 54 that projects downwards. An annular projection 55 projects from the periphery of the lower end of the base plate 52 . A lateral pump port 56 is provided in a side wall of the chamber and a connecting tube 30 can be connected to this port. An annular shoulder 57 is located atop the chamber around its inner surface.
[0039] The second body member 60 is sized so that at least a lower portion of it fits snugly into an opening atop the first body member 51 to abut the shoulder and form a seal with chamber 58 . The second body member 60 has an annular projection 65 projecting downwards from its lower end. The annular projection 65 has a shape that is complementary to the annular shoulder 57 of the first body member 51 . In this way, when the second body member 60 is fitted into the first body member 51 , the annular shoulder 57 and the annular projection 65 form an annular clamp. It will be appreciated that the shoulder 57 and the projection 65 could be reversed. A flexible membrane 59 is clamped between the annular shoulder 57 and the annular projection 65 . The distance (I) between the top surface of this flexible membrane 65 and the central axis of the pump port 56 is at least about 20 cm. This helps ensure that an air pocket does not pass into the pump port and to a pump where it may be detected by a sensor associated with the pump.
[0040] An opening 61 in the upper surface of the second body member 60 provides an inlet port and an inlet tube 12 , 22 may extend from this port. An opening 62 in the lower surface of the second body member 60 has an annular rim 64 which projects into the chamber 58 .
[0041] The third body member 70 is in the form of a channel. An annular shoulder 77 is provided atop the third body member 70 around its inner surface. The annular shoulder 77 has a shape complementary to the lower end of the annular projection 55 of the first body member 51 . In this way, when the first body member 51 abuts the third body member 70 , the annular projection 55 and the annular shoulder 77 form an annular clamp. It will be appreciated that the annular shoulder 77 and the projection 55 could be reversed. Further, the annular projection 55 of the first body member 51 is sized to fit snugly in the bore of the third body member 70 to form a seal. A flexible membrane 69 is clamped between the annular projection 55 of the first body member 51 and the annular shoulder 77 of the third body member 70 . A lower opening 72 in the third body member 70 provides an outlet from which an outlet tube 11 , 21 may extend.
[0042] In an alternative embodiment, for example as shown in FIG. 2, the chamber may include tubing. The first body member may include a chamber which has and inlet port, an outlet port, and a pump port. The second body member may hold a first flexible membrane and it may be connected via tubing to the first body member. The third body member may hold a second flexible membrane and it may be connected via tubing to the first body member.
[0043] The two flexible membranes 59 , 69 are made of a resilient flexible material, typically a sterilisable material such as silicon, rubber or any other suitable material. The membranes each have a plurality of slits (for example two) which, in the rest state, are closed and do not permit flow of fluid. Typically, the membranes 69 are designed so that their slits 66 will open only when the pressure differential over the membrane exceeds about 20 kPa. This prevents undesired free flow of the fluid from the containers 4 , 5 , which in a clinical setting are typically placed on a stand of a height of about 1.5 metres. Typically, the membranes 59 are designed so that their 67 slits will open under a small pressure differential of about 0 kPa.
[0044] A pump 32 of a pump unit 33 is coupled to the connecting tube 30 . The pump 32 is preferably a peristaltic pump but any pump which is able to pump fluid at controlled flow rates in both directions and which is suitable for clinical applications may be used. The pump unit 33 may include a control unit 34 . The control unit 34 typically comprises a control panel which has a display and a key pad. The key pad may be used for manual control of the pump, data entry, and the like. The control unit may include a microprocessor for controlling and activating the pump. A memory may be associated with, or be incorporated in, the microprocessor. If desired, the control unit may include an audio, visual or dual alarm signalling means.
[0045] The pump unit 33 has a socket which is complementary to the shaped connecting element 31 . When the pump system is correctly assembled, the shaped element 31 fits into the socket in the pump unit 33 . The pump unit 33 may be provided with a micro switch in the socket which generates a signal when the shaped connecting element 31 is fitted in the socket. This signals to the control unit that the pump system has been correctly assembled. The control unit may be programmed not to initiate the pump 32 unless the correct signal has been received.
[0046] The flow set 1 is typically mounted on a stand with the containers 4 and 5 being held by an arm at the top of the stand.
[0047] Drip chambers 2 , 3 may be provided adjacent the outlets 72 of the valve arrangements 10 , 20 or between the containers and the inlets of the valve arrangements.
[0048] In use, pump 32 pumps fluid from one of the containers 4 or 5 to a patient. For example, the pump 32 draws fluid from the left hand container 4 of FIG. 2. The fluid is drawn into the inlet tube 12 , through the drip chamber 2 , and into the inlet 61 of the valve arrangement 10 .
[0049] Prior to pumping by the pump 32 , the flexible membranes 59 , 69 are in the rest state. When fluid is drawn through the inlet tube 12 , the flexible membrane 59 is stretched. Once a selected small threshold pressure differential is reached and the first flexible membrane 59 is sufficiently stretched, it deforms and slits in the membrane 59 widen and open to allow flow of fluid from the inlet tube 12 into the chamber 58 .
[0050] Simultaneously, the suction of the pump 32 reduces the pressure in the pump port, in the connecting tube 30 and in the chamber 58 . This causes the second flexible membrane 69 to seal against the annular rim of base plate 52 of the first body member 51 . Fluid flows from the chamber 58 through the pump port 56 and into the connecting tube 30 . Fluid is unable to penetrate through the second flexible membrane 69 .
[0051] Fluid is propelled by the pump 32 along the connecting tube to the chamber of a second valve arrangement 20 . Fluid enters the valve arrangement 20 through its lateral pump port 56 . Once in the chamber 58 of a second valve arrangement, the fluid pressure forces the first flexible membrane 59 for the valve arrangement upwards against the annular rim of second body member 60 . This membrane cannot deflect sufficiently to permit fluid flow through it. However, when the positive pressure induced in the chamber 58 by the pump 32 reaches a pressure of at least about 20 kPa it causes the second flexible membrane 69 to stretch and deform. Once the selected threshold pressure differential is reached and the second flexible membrane 69 is sufficiently stretched, slits in the membrane 69 widen and open to allow flow of fluid from the chamber 58 out of the outlet port 72 to outlet tube 21 .
[0052] The fluid flows through the outlet tube 21 , through a Y-connector 40 , and into an administration tube 41 . A small amount of fluid may initially flow into the left-hand second tubing element 11 but it is prevented from entering the first valve arrangement 10 by the second flexible membrane 69 of this valve arrangement.
[0053] Administration of a second fluid is achieved by reversing the pumping direction of the pump 32 . The pumping direction of the pump 32 may be reversed manually or automatically at selected times by a control unit.
[0054] The system provides a safe and rapid means of sequentially administering two fluids to a patient which is extremely simple to operate.
[0055] It will be appreciated that numerous modifications may be made to the preferred embodiments by one of ordinary skill I the art. For example, it is not essential for drip chambers 2 , 3 to be connected in the flow set 1 . It is also not essential to provide the pump 32 with a socket and the connecting tube 30 with a shaped connecting element 31 . Similarly, the Y-connector 40 may be replaced with any suitable connector. Similarly, the flow set need not use the membrane type valves described above. Other valves may be used; for example each valve may be replaced with a one way valve which opens upon the correct threshold pressure being reached. The connecting tube 30 may then extend from a position between the pair of one way valves of each assembly. These and other modifications and variations that do not depart from the spirit and scope of the invention form part of the subject matter that is set forth in the following claims. | A valve arrangement is described for providing clinical nutrition. The arrangement comprises a split flushing valve. Also described are a method of production of the valve arrangement, use of the valve arrangement in providing nutrition to a patient and a method of treatment of a patient that comprises administering an effective amount of a composition via the valve arrangement | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to a method of constructing brass instruments and more particularly to a method of forming the mouthpipe of a brass instrument to include a zone of increased taper which significantly improves the intonation of the entire upper octave of the instrument's normal playing range. (I.e., for purposes of this application, brass instruments comprise wind instruments having a cup mouthpiece and a cylindrical bore.)
Although the origins of brass instruments have been traced back hundreds of years to man's primitive ancestors, the basic form of the modern valved trumpet derived in the early 1800's. Since that time, consistent efforts have been made to improve the harmonic or intonation qualities of the instrument. To date, most of these improvements have focused upon the configuration of the bell portion of the trumpet.
In relation to the bell portion, it has been found that by flaring the open end of the trumpet to increase in diameter as the opened end is approached, the frequencies of the lower note resonances are shifted upward. Additionally, if the total length of the trumpet is properly adjusted for the particular bell shape, the higher note resonances will remain unchanged. Thus, with a properly shaped bell portion, the majority of note frequencies will be shifted into a form approximating a true harmonic series.
Although these improvements have proven beneficial in their general application, there exists inherent limitations in their operation which must be constantly corrected during playing by the musician. In particular, it is well known that trumpets constructed of conventional design fail to provide a chromatic scale that is nominally true to desired pitch for the entire upper octave of the instrument. (I.e., from the D natural (D 5 ) above the 4 partial C-natural (C 5 ) to the A natural (A 5 ) above.) Thus, with a conventional soprano trumpet in "C", the E 5 (659 Hz) note is typically flat enough to be audibly detectable in many playing situations, whereas the F 5 , G 5 (740 Hz) G sharp 5 (831 Hz) and A 5 (880 Hz) notes are all very sharp. Heretofore, to intonate these upper octave notes in proper pitch, the musician would be required to conscienciously correct these normally out-of-tune notes by either extending a valve slide and/or false fingering of the trumpet valves.
Additionally, in the conventional trumpet design, the tuning slide is utilized to initially tune the instrument to desired pitch, being typically pulled outward away from the upper branch through a distance of 3/8 to 3/4 of an inch in order for the musician to play at a pitch corresponding to A=440 Hz (standard orchestration pitch). This extension of the tuning slide locally increases the bore of the instrument both in the upper and lower branch which flattens certain notes (i.e., the D sharp 5 and E 5 ) on the chromatic scale as well as produces turbulence within the instrument. This turbulence adversely affects the playability or action of the instrument which must further be constantly compensated for by the musician. Thus, there exists a need in brass instruments for a construction which corrects the chromatic scale throughout the entire upper octave of the normal playing range without adversely affecting the action and total resonance of the instrument.
SUMMARY OF THE PRESENT INVENTION
The present invention provides a novel construction for trumpets and other brass instruments which results in an improved acoustical shape of the air column between the mouthpiece and valve section of the instrument. This improved acoustical shape comprises a zone of increased taper which is precisely located for each particular instrument along the length of the mouthpipe and merges smoothly with the main cylindrical bore of the instrument. The zone of increased taper coincides with the pressure maximum points of the standing waves of selected notes to correct the pitch of the notes propogated through the instrument.
The improved instrument construction of the present invention specifically results in improved intonation (i.e., corrected pitch) in the chromatic scale from the D natural above the 4th partial (C natural) to the B natural and above without adversely altering the remaining playing range of the instrument. For example, when the construction of the present invention is employed on a soprano "C" trumpet, the 5th partial E natural is raised (as compared with conventional trumpet construction) to its proper pitch in the tempered scale and the 6th partial G natural is lowered (as compared with conventional construction) to its proper pitch. Further, the construction of the present invention also raises the normally flat E flat note immediately above the 5th partial and lowers the normally sharp G sharp and A natural above the 6th partial. As such, the present invention provides a brass instrument which is capable of intonating a chromatic scale that is nominally true to pitch for the entire upper octave of the instrument and thereby eliminates the need to consciously employ valve slide extensions and false fingering techniques heretofore required of musicians during playing of the instrument.
Further, the present invention eliminates the manditory incorporation of a movable double branch tuning slide with tuning of the instrument being accomplished by the position of the mouthpipe. Moreover, the mouthpipe is constructed to merge smoothly with the main cylindrical bore of the instrument thereby eliminating the zone of locally increased bore attendant with the conventional trumpet's tuning slide design.
DESCRIPTION OF THE DRAWINGS
These and other features of the present invention will become more apparent upon reference to the drawings wherein:
FIG. 1 is a cross-sectional view of the upper and lower branch of a conventional trumpet showing the mouthpiece, mouthpipe, and tuning slide and depicting the zones of increased bore;
FIG. 2 is a cross-sectional view of the upper and lower branch of a trumpet constructed in accordance with the present invention showing the mouthpiece, mouthpipe, and mouthpipe receiver and depicting a zone of increased taper;
FIG. 3 is a schematic representation of the displacement and pressure curves of the standing wave generated in a trumpet;
FIG. 4 is a graph of the radius of taper through the mouthpipe of the present invention plotted against the distance from the mouthpiece end of the mouthpipe;
FIG. 5 is a graph of the deviation in semi-tones in the upper octave of the chromatic scale produced by the conventional trumpet construction of FIG. 1;
FIG. 6 is a graph of the deviation in semi-tones of notes of the upper octave of the chromatic scale produced by the trumpet shown in FIG. 2 and constructed in accordance with the present invention; and
FIG. 7 is a graph of FIGS. 5 and 6 superimposed upon one another illustrating the decrease in deviation between a conventional trumpet and a trumpet produced in accordance with the teachings of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown the upper and lower branch 1 and 3, respectively, of a conventional trumpet. The upper branch 1 is composed of a mouthpiece 5, mouthpiece receiver 7, mouthpiece (or leadpipe) 9, and a tuning slide receiver 11 which are connected in an end-to-end relationship. As is well known, a valve set (not shown) and valve extension (not shown) are additionally included to selectively vary the effective tubing length of the instrument. Typically, the tuning slide receiver 11 is rigidly connected at one end to the mouthpipe 9 (as by a solder joint) and slidingly receives at the other end one leg of a tuning slide 13 which interconnects the upper and lower branches 1 and 3, respectively. The lower branch 3 additionally includes a tuning slide receiver 15 which similarly receives the lower leg of the tuning slide 13. As will be recognized, by manually sliding the tuning slide 13 toward and away from the mouthpiece 5, the effective tubing length of the instrument may be varied to properly tune the instrument to a desired pitch. Additionally, the extension of the tuning slides forms an upper and lower zone of increased bore 17 and 19 on both the upper and lower branches 1 and 3, respectively, of the instrument, which, as will be explained in more detail below, may adversely effect the intonation of the instrument.
The mouthpiece 5 and mouthpipe 9 are both formed having a tapered or conical shaped inner wall 21 and 23 which has been found to yield a suitable air column for the intonation of a harmonic standing wave series. As is well known, an energy impulse may be created by expelling air under pressure through the mouthpiece 5 to produce a vibration. The mouthpiece 5 and mouthpipe 9 as well as the remainder of the trumpet provides an open-ended air column which propogates the standing wave produced by the vibration.
Referring to FIG. 3, the details of the standing wave produced within the instrument are illustrated schematically. At point A (corresponding to the throat of the mouthpiece 5 in FIG. 1), the expulsion of air by the musician generates a compression impulse which moves within the tube 22 of the trumpet from left to right. This compression impulse produces a displacement impulse D 1 which additionally travels within the tube 22 from left to right) in a sinusoidal wave configuration. Upon reaching the open end B of the air column (representing the bell portion (not shown) of the instrument), the displacement impulse D 1 is reflected unchanged in the opposite direction (i.e., from right to left), producing a reflected displacement impulse D 2 . Since the displacement curves D 1 and D 2 are mirror images of one another, a standing longitudinal displacement wave is produced within the tube 22 of the instrument.
As the displacement waves D 1 and D 2 travel within the tube 22, the air molecules of the air column are pulled apart and crowded together creating regions of lower and higher pressure, respectively. Thus, a pair of pressure waves P 1 and P 2 may be plotted within the air column corresponding to the displacement waves D 1 and D 2 .
As shown in FIG. 3, at the open end of the tube 22, the pressure initiates at a maximum value PM 1 (i.e., the 1st pressure maximum point) and propogates as a sinusoidal wave P 1 through the length of the air column having a 2nd pressure maximum point PM 2 , etc. Similarly, a second sinusoidal wave P 2 propogates through the air column in a direction opposite P 1 and following the reflected displacement curve D 2 . As shown, the pressure curves P 1 and P 2 are out of phase with the displacement curves D 1 and D 2 such that maximum pressure is developed at points PM 1 and PM 2 corresponding to minimum displacement within the tube 22.
Although for illustration purposes FIG. 3 has been presented with a straight cylindrical tube air column configuratiion, the same principles apply to conical shaped air columns with the only exception being the elongation of the wave series as they expand in an increasing area air column. Thus, by propogating the standing wave in a conical shaped air column, the location of maximum pressure points PM 1 and PM 2 , etc., along the air column may be longitudinally expanded or displaced along the length of the tube. A more complete discussion of the propogation of standing waves through brass instruments is presented in the ACOUSTICAL FOUNDATIONS OF MUSIC, 2nd edition, John Backus, 1977, W. W. Norton & Company, Inc., the disclosure of which is expressly incorporated herein by reference.
As will be recognized, each note initiated by a musician into the mouthpiece 5 of the trumpet will generate a displacement and pressure curve series similar to that shown in FIG. 3 with each note having a different sinusoidal wave pattern and varying locations of their maximum pressure PM 1 and PM 2 and maximum displacement points along the air column.
Based upon this physical relationship of standing waves in air columns, it has long been known that by locally increasing the bore (i.e., the diameter) of the air column at the location of a pressure maximum point of a particular note, the pitch of that particular note or any other note having a pressure maximum point at the same location will be lowered.
Thus, during playing of the conventional trumpet of FIG. 1, the notes generated by the musician whose pressure maximum points are located in either of the zones of increased bore 17 and 19 will have their pitch lowered. In conventional "C" trumpet designs, the particular notes having their pressure maximum points PM 2 , etc., coincident with the zones of increased bore 17 and 19 are the D sharp 5 and E 5 notes. As such, these two notes are normally out-of-tune in conventional trumpet designs.
Thus, heretofore musicians playing a conventional trumpet were required to consciously correct the normally out-of-tune notes as by false valving, "lipping", or valve slide extension techniques.
Further, by use of the conventional tuning slide design, a shoulder 27 is formed at both ends of the zones of increased bore 17 and 19 by the difference in diameters between the tuning slide 13 and the upper and lower branch 1 and branch 3 of the instrument. These shoulders 27 often disrupt the normal sinuosidal wave of the note propogated through the instrument and increase turbulence within the air column which may adversely effect the sound of the instrument.
Referring to FIG. 2, the modified construction of the present invention which provides an improved acoustical shape of the air column of the trumpet is shown. The construction includes an upper and lower branch 31 and 33 which are interconnected by way of a conventional tuning slide 35. However, in the preferred embodiment, the tuning slide 35, although being typically reciprocal, which is desirable for cleaning purposes as in a conventional trumpet, is continuously maintained in its retracted position during playing such that a continuous bore diameter 34 is maintained at its interface with the upper and lower branches 31 and 33. As such, the prior art zones of increased bore (17 and 19 in FIG. 1) and the turbulence producing shoulders (27 in FIG. 1) are completely eliminated by the present invention construction.
The upper branch 31 is preferably formed as the straight cylindrical tubular section 37 which slidingly receives at one end thereof a mouthpipe assembly 39. The mouthpipe assembly 39 comprises an elongate tube being preferably formed by a mouthpiece receiver section and a bore section 38 and 40, respectively, which are mounted to one another as by a solder joint 42. The mouthpiece 41 is mounted to the receiver section 38 in a well known manner and the entire mouthpipe assembly 39 may reciprocate within the length of the tubular section 37 and be locked in a desired position by a clamping screw 41.
The mouthpipe assembly 39 includes an internal bore 43 formed in a conical or tapered configuration which is maintained in a substantially lineal configuration throughout the majority of its length. However, at the distal end thereof, the taper of the internal bore 43 is increased to provide a zone of increased taper 45. This zone of increased taper 45 has been found to correct certain intonation faults in the instrument as will be discussed in more detail below.
To initially tune the trumpet of the present invention to a desired orchestral pitch, it is not necessary and actually undesirable to reciprocate the tuning slide 35 within the upper and lower branches 31 and 33 as in the conventional trumpet design, but rather the mouthpipe assembly 39 (and thus the mouthpiece 41) need only be reciprocated within the tubular section 37. By this reciprocation, the effective length of the air column in the trumpet is altered thereby adjusting the overall pitch of the instrument.
The particular location of the zone of increased taper 45 of the present invenion as well as the amount or slope of increased taper is critical and varies between individual instruments but in all cases is maintained such that the zone 45 coincides with the maximum pressure points of the notes of the chromatic scale desired to be corrected. In this same regard, the taper of the substantially cylindrical bore 43 of the bore section 40 which is formed similar to the tapered mouthpipe of a conventional trumpet must be maintained unchanged to insure that the many desirable pitch qualities of the conventional trumpet are retained.
While being played, the zone of increased taper 45 of the present invention functions to selectively increase the bore diameter of the air column of the instrument. As such, particular notes having their pressure maximum points located within the zone 45 are effectively lowered in pitch. By properly positioning the zone 45 along the length of the air column and determining the amount of increased slope of the taper zone 45, the pitch of multiple notes may be lowered or corrected in varying magnitude.
With particular reference to a soprano "C" trumpet, the applicant has found that the normally out-of-tune upper octave (i.e., from the D natural above the 4th partial (C natural) to the A natural above) may be corrected by initiating the zone of increased taper at a distance of approximately 2.75 plus or minus 0.065 inches from the end of the mouthpiece 41. This particular location has been experimentally determined to be between the 2nd pressure maximum points (as shown in FIG. 3) of the A 5 and A sharp 5 notes such that the zone of increased taper lowers the pitch of the A 5 note without lowering the pitch of the A sharp 5 note which is a half-tone higher along the chromatic scale.
Referring to FIG. 4, the particular construction of the taper within the bore section 40 of the mouthpipe assembly 39 for the soprano "C" trumpet (as illustrated in FIG. 2) is depicted in graphic form. As shown, the radius of the taper increases gradually to form a slight curved line which approximates a substantially linear rate (i.e., slope ≈0.011) to a distance of approximately 2.75 inches from the small end of the mouthpiece 41. From this location (labelled T on FIG. 4) the taper is substantially increased (i.e., slope ≈0.020) through a distance of slightly less than one inch (to a position T 1 indicated on FIG. 4). Thus, the magnitude of taper in the zone 45 (i.e., from T 1 to T 2 ) is approximately twice the magnitude of taper in the remainder of the bore section 40 of the mouthpipe assembly 39.
The dramatic improvement in the intonation of notes of the upper octave of the soprano "C" trumpet by use of the construction of the present invention is shown in FIGS. 5, 6, and 7. All test data plotted in FIGS. 5, 6, and 7 was obtained under tests conducted by carefully blowing the trumpet of FIGS. 1 and 2, using a commercial electronic tuning meter to determine the pitches produced.
In these figures, the notes of the upper octave of the trumpet are plotted on the horizontal axis of the graph whereas the amount of deviation from the true note on a tempered scale is plotted on the vertical axis (being represented in hundredths of a semi-tone flat or sharp). Further, since the human ear is capable of only differentiating discrepancies in pitch of approximately 5/100ths of a semi-tone, the graphs in FIGS. 5, 6 and 7 include a zone of acceptable deviation in pitch defined by the area between the horizontal lines labelled P 1 and P 2 .
In FIG. 5, the data obtained by testing one of the most popular conventional design models of soprano "C" trumpets (Bach "large" bore C trumpet with 229 bell, manufactured by Vincent Bach Corporation, Elkhart, Indiana) is reproduced. For purposes of this series of tests, the instrument was tuned to G 4 , a tuning which keeps the C 6 note comfortably within the limits of audible detectability, i.e., within the region between lines P 1 and P 2 .
As shown, the conventional trumpet, although being utilized by many of the major symphony orchestras, has substantial intonation deficiences in the upper octave that would require conscious correction (as by slide extension or false fingering) by the performer. Thus, the E 5 is significantly flat enough to be audibly detected in many playing situations. Additionally, the F 5 (one-half tone higher) is quite sharp, being over 20/100ths of a semi-tone sharper in deviation than the E 5 . Further, the G sharp 5 and E sharp 5 are extremely sharp, approximately 25 to 28/100ths of a semi-tone, respectively.
In FIG. 6, the data obtained in a similarly conducted test with the same model trumpet as FIG. 5 but modified according to the teachings of the present invention is reproduced. It is evident from the graph that all of the formerly defective note pitches are now substantially in tune with the majority of the notes lying between the lines P 1 and P 2 . In particular, the notes D sharp 5, E 5 , F sharp 5, and G 5 are all within the limits of human detectability. Further, the notes G sharp 5 and A 5 are only 1/100th semi-tone outside the limits of human detectability and can be easily lipped into tune with normal fingering and without valve slide extension.
This dramatic improvement in intonation made possible by the modified construction of the present invention is graphically depicted in FIG. 7 wherein FIGS. 5 and 6 are superimposed onto one another. As will be recognized, the modification of the present invention has lowered (by way of the zone of increased taper 45 in FIG. 2) the G sharp 5 and A 5 note approximately 27 and 26/100ths of a semi-tone, respectively, and additionally has raised (by way of the elimination of the zones of locally increased bore 17 and 19 in FIG. 1) the D sharp 5 and E 5 notes 10/100ths of a semi-tone. Thus, by way of the present invention, a chromatic scale that is nominally true to the desired pitch for the entire upper octave of the instrument is provided.
Those skilled in the art will realize that the teachings of the present invention, although being illustrated in relationship to a soprano "C" trumpet, are additionally applicable to other trumpets such as B flat, D, E flat, or F, as well as other cup mouthpiece brass instruments. Further, although for the key of C trumpet tested and disclosed herein, the beginning of the zone of increased tape is located precisely at 2.75 inches from the small end of the mouthpiece, other trumpets as well as other brass instruments may require a relocation of the zone of increased taper to correct the higher octaves which are normally out of tune. In this same regard, the amount or magnitude of increased taper of the present invention which is illustrated in FIG. 4 may be varied between the normal mouthpiece configuration (represented by the dash line in FIG. 4) to a line approaching vertical on the graph. In such a manner, any particular trumpet may be finely tuned to compensate for the discrepancies of the intonation of different instruments to produce a true tempered scale for an instrument. | A method of constructing a trumpet or other brass instrument is disclosed wherein a zone of increased taper is formed on the cylindrical inner surface of the mouthpipe to provide an improved air column between the mouthpiece and valve sections of the instrument. The zone of increased taper is critically positioned along the length of the mouthpipe to coincide with the pressure maximum points of selected notes in the upper octave of the normal playing range of the instrument to yield a chromatic scale that is nominally true to desired pitch. | 6 |
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] The present application claims priority to Japanese Patent Application JP 2007-297321 filed in the Japanese Patent Office on Nov. 15, 2007, Japanese Patent Application JP 2007-297323 filed in the Japanese Patent Office on Nov. 15, 2007, and Japanese Patent Application JP 2007-297325 filed in the Japanese Patent Office on Nov. 15, 2007, the entire contents of which are being incorporated herein by reference.
BACKGROUND
[0002] The present application relates to a piezoelectric device used in a piezoelectric sensor, a piezoelectric actuator, and a pyroelectric infrared ray sensor, an angular velocity sensor including the piezoelectric device, and a method of manufacturing a piezoelectric device.
[0003] From the past, lead zirconium titanate (Pb 1+X (Zr Y T 1−Y )O 3+X ) (hereinafter, referred to as PZT) is used as a piezoelectric material of a piezoelectric thin film used for a piezoelectric sensor such as an angular velocity sensor, an ink jet head, and the like. Various techniques are proposed for improving piezoelectric characteristics, ferromagnetic material characteristics, pyroelectric characteristics, and the like of the PZT (see, for example, Japanese Patent Application Laid-open No. Hei 06-350154 (paragraphs (0030) to (0044), (0060) to (0073), FIGS. 3 , 4 , etc.) and Japanese Patent Application Laid-open No. Hei 09-298324 (paragraphs (0007) to (0009), FIG. 5 ); hereinafter, will respectively be referred to as Patent Document 1 and Patent Document 2).
[0004] Patent Document 1 discloses a PZT thin film whose crystalline structure is rhombohedral, in which, when lead zirconium titanate is represented by Pb 1+Y (Zr X T 1−X )O 3+Y , a PbO excessive composition ratio Y is within a range of 0≦Y≦0.5, and a Zr composition ratio X is within a range of 0≦Y≦0.55. The PZT thin film of Patent Document 1 exhibits favorable piezoelectric characteristics. Moreover, there is also disclosed a PZT thin film whose crystalline structure is tetragonal, in which the PbO excessive composition ratio Y is within a range of 0≦Y<0.5, and the Zr composition ratio X is within a range of 0.55≦X<1.
[0005] Patent Document 2 discloses a piezoelectric thin film having a thickness of 1 μm or more and 10 μm or less, a crystal grain size of 0.55 μm or less, and surface roughness of 1 μm or less at R MAX . The piezoelectric thin film is useful as a piezoelectric thin film for an ink-jet-type storage apparatus that requires a predetermined film thickness or more.
SUMMARY
[0006] Incidentally, when heated, the piezoelectric material is known to deteriorate in piezoelectric performance, which is called depolarization. However, because heating processing by solder reflow and the like is generally carried out in a process of manufacturing an electronic apparatus that includes the piezoelectric material, there is a problem that the piezoelectric performance of the piezoelectric material deteriorates due to the heat.
[0007] Particularly in recent years, a solder reflow temperature is increasing due to lead-free soldering in consideration of environmental problems, and heat caused by the solder reflow causes the piezoelectric performance of the piezoelectric material to deteriorate, which is problematic. However, Patent Documents 1 and 2 above give no consideration to the effect of heat.
[0008] Further, there is a problem that when the piezoelectric member is to have a film thickness of 1 μm or more as described in Patent Document 2, a possibility of cracks being caused or crystallinity being deteriorated increases. The deterioration of the crystallinity may also become a cause of the depolarization due to the heating processing.
[0009] In view of the above circumstances, there is a need for a piezoelectric device excellent in piezoelectric characteristics and heat resistance, an angular velocity sensor including the piezoelectric device, and a method of manufacturing a piezoelectric device.
[0010] According to an embodiment, there is provided a piezoelectric device including a piezoelectric film and an electrode film. The piezoelectric film is constituted of lead zirconium titanate represented by Pb 1+X (Zr Y Ti 1−Y )O 3+X , where X is 0 or more and 0.3 or less and Y is 0 or more and 0.55 or less, the piezoelectric film having a tension stress. The electrode film applies a voltage to the piezoelectric film.
[0011] By setting a PbO excessive composition ratio X of the PZT to be 0 or more and 0.3 or less and a Zr composition ratio Y to be 0 or more and 0.55 or less, a piezoelectric device excellent in piezoelectric characteristics can be obtained. If the Zr composition ratio Y is 0 or more and 0.55 or less, depolarization hardly occurs and excellent heat resistance can be obtained.
[0012] In addition, by providing the tension stress to the piezoelectric film, a piezoelectric device with additionally-improved heat resistance can be obtained.
[0013] In the piezoelectric device according to an embodiment, the tension stress of the piezoelectric film may be 50 MPa or more and 500 MPa or less. Accordingly, a piezoelectric device with additionally-improved heat resistance can be obtained.
[0014] In the piezoelectric device according to an embodiment, the piezoelectric film may have a film thickness of 400 nm or more and 1,000 nm or less.
[0015] Accordingly, a piezoelectric device with additionally-improved piezoelectric characteristics can be obtained.
[0016] In the piezoelectric device according to an embodiment, the electrode film may have a tension stress of 500 MPa or more and 1,500 MPa or less.
[0017] Accordingly, a piezoelectric device with additionally-improved heat resistance can be obtained.
[0018] In the piezoelectric device according to an embodiment, the piezoelectric film may have an orientation of 80% or more in a <111> direction.
[0019] Accordingly, a piezoelectric device with additionally-improved heat resistance can be obtained.
[0020] In the piezoelectric device according to an embodiment, the piezoelectric film may include at least one of additive elements selected from the group consisting of Cr, Mn, Fe, Ni, Mg, Sn, Cu, Ag, Nb, Sb, and N.
[0021] In the piezoelectric device according to an embodiment, the electrode film may be formed of at least one of Ti and Pt. The electrode film may also be formed of Ir, Au, and Ru, or oxides of Ti, Pt, Ir, Au, and Ru.
[0022] According to another embodiment, there is provided a piezoelectric device including a piezoelectric film and an electrode film. The piezoelectric film is constituted of lead zirconium titanate represented by Pb 1+X (Zr Y Ti 1−Y )O 3+X , where X is 0 or more and 0.3 or less and Y is 0 or more and 0.55 or less. The electrode film has a tension stress of 500 MPa or more and 1,500 MPa or less and applies a voltage to the piezoelectric film.
[0023] By setting the PbO excessive composition ratio X of the PZT to be 0 or more and 0.3 or less and the Zr composition ratio Y to be 0 or more and 0.55 or less, a piezoelectric device excellent in piezoelectric characteristics can be obtained. If the Zr composition ratio Y is 0 or more and 0.55 or less, depolarization hardly occurs and excellent heat resistance can be obtained.
[0024] In addition, by providing the tension stress of 500 MPa or more and 1,500 MPa or less to the electrode film, a piezoelectric device with additionally-improved heat resistance can be obtained.
[0025] In the piezoelectric device according to an embodiment, the piezoelectric film may have a film thickness of 400 nm or more and 1,000 nm or less.
[0026] Accordingly, a piezoelectric device with additionally-improved piezoelectric characteristics can be obtained.
[0027] In the piezoelectric device according to an embodiment, the piezoelectric film may have a tension stress of 50 MPa or more and 500 MPa or less.
[0028] Accordingly, a piezoelectric device with additionally-improved heat resistance can be obtained.
[0029] In the piezoelectric device according to an embodiment, the piezoelectric film may have an orientation of 80% or more in a <111> direction.
[0030] Accordingly, a piezoelectric device with additionally-improved heat resistance can be obtained.
[0031] In the piezoelectric device according to an embodiment, the piezoelectric film may include at least one of additive elements selected from the group consisting of Cr, Mn, Fe, Ni, Mg, Sn, Cu, Ag, Nb, Sb, and N.
[0032] In the piezoelectric device according to an embodiment, the electrode film may be formed of at least one of Ti and Pt. The electrode film may also be formed of Ir, Au, and Ru, or oxides of Ti, Pt, Ir, Au, and Ru.
[0033] According to another embodiment, there is provided a piezoelectric device including a piezoelectric film and an electrode film. The piezoelectric film is constituted of lead zirconium titanate represented by Pb 1+X (Zr Y Ti 1−Y )O 3+X , where X is 0 or more and 0.3 or less and Y is 0 or more and 0.55 or less, the piezoelectric film having a film thickness of 400 nm or more and 1,000 nm or less. The electrode film applies a voltage to the piezoelectric film.
[0034] By setting the PbO excessive composition ratio X of the PZT to be 0 or more and 0.3 or less and the Zr composition ratio Y to be 0 or more and 0.55 or less, a piezoelectric device excellent in piezoelectric characteristics can be obtained. If the Zr composition ratio Y is 0 or more and 0.55 or less, depolarization hardly occurs and excellent heat resistance can be obtained.
[0035] In addition, by setting the film thickness to be 400 nm or more and 1,000 nm or less, a piezoelectric device with additionally-improved piezoelectric characteristics can be obtained.
[0036] In the piezoelectric device according to an embodiment, the piezoelectric film may have an orientation of 80% or more in a <111> direction.
[0037] Accordingly, a piezoelectric device with additionally-improved heat resistance can be obtained.
[0038] In the piezoelectric device according to an embodiment, the piezoelectric film may include at least one of additive elements selected from the group consisting of Cr, Mn, Fe, Ni, Mg, Sn, Cu, Ag, Nb, Sb, and N.
[0039] In the piezoelectric device according to an embodiment, the electrode film may be formed of at least one of Ti and Pt. The electrode film may also be formed of Ir, Au, and Ru, or oxides of Ti, Pt, Ir, Au, and Ru.
[0040] According to another embodiment, there is provided an angular velocity sensor including a substrate, a first electrode film, a piezoelectric film, and a second electrode film. The first electrode film is formed on the substrate. The piezoelectric film is constituted of lead zirconium titanate represented by Pb 1+X (Zr Y Ti 1−Y )O 3+X , where X is 0 or more and 0.3 or less and Y is 0 or more and 0.55 or less, the piezoelectric film having a tension stress and formed on the first electrode film. The second electrode film is formed on the piezoelectric film.
[0041] According to another embodiment, there is provided an angular velocity sensor including a substrate, a first electrode film, a piezoelectric film, and a second electrode film. The first electrode film has a tension stress of 500 MPa or more and 1,500 MPa or less and is formed on the substrate. The piezoelectric film is constituted of lead zirconium titanate represented by Pb 1+X (Zr Y Ti 1−Y )O 3+X , where X is 0 or more and 0.3 or less and Y is 0 or more and 0.55 or less, the piezoelectric film formed on the first electrode film. The second electrode film is formed on the piezoelectric film.
[0042] According to another embodiment, there is provided an angular velocity sensor including a substrate, a first electrode film, a piezoelectric film, and a second electrode film. The first electrode film is formed on the substrate. The piezoelectric film is constituted of lead zirconium titanate represented by Pb 1+X (Zr Y Ti 1−Y )O 3+X , where X is 0 or more and 0.3 or less and Y is 0 or more and 0.55 or less, the piezoelectric film having a film thickness of 400 nm or more and 1,000 nm or less and formed on the first electrode film. The second electrode film is formed on the piezoelectric film.
[0043] According to an embodiment, a piezoelectric device excellent in piezoelectric characteristics and heat resistance, an angular velocity sensor including the piezoelectric device, and a method of manufacturing a piezoelectric device can be provided.
[0044] Additional features and advantages are described herein, and will be apparent from the following Detailed Description and the figures.
BRIEF DESCRIPTION OF THE FIGURES
[0045] FIGS. 1 are diagrams showing a piezoelectric device and an angular velocity sensor including the piezoelectric device according to a first embodiment;
[0046] FIG. 2 is a diagram showing an XRD (X-ray diffraction) pattern of a PZT thin film;
[0047] FIG. 3 is a diagram showing a relationship between a film thickness (100 nm to 1,400 nm) of the PZT thin film and a piezoelectric constant d31;
[0048] FIG. 4 is a diagram showing relationships of a PbO excessive composition ratio X (−0.1 to 0.5) of the PZT thin film with the piezoelectric constant d31 and a loss rate tan δ;
[0049] FIG. 5 is a diagram showing a relationship between a Zr composition ratio Y (0.35 to 0.65) of the PZT thin film and the piezoelectric constant d31;
[0050] FIG. 6 is a diagram showing a relationship between the Zr composition ratio Y (0.35 to 0.7) of the PZT thin film and an attenuation rate of a vibration arm after application of heat;
[0051] FIG. 7 is a diagram showing a relationship between a heating time and the amplitude attenuation rate after application of heat in a case where a heating temperature is set to 240°;
[0052] FIG. 8 is a diagram showing a relationship between the heating temperature and the amplitude attenuation rate after application of heat;
[0053] FIG. 9 is a diagram showing a relationship between a stress (−100 MPa to 600 MPa) of the PZT thin film and the amplitude attenuation rate after application of heat;
[0054] FIG. 10 is a diagram showing a relationship between a stress (−500 MPa to 2,000 MPa) of a first electrode film and the amplitude attenuation rate after application of heat;
[0055] FIG. 11 is a diagram showing a relationship between an orientation degree of the PZT in a <111> surface direction and the amplitude attenuation rate of the vibration arm after application of heat;
[0056] FIG. 12 is a diagram showing a relationship between a ratio of a polarization voltage in polarization processing with respect to a coercive electric field (1 to 20-times the coercive electric field E c ) and the amplitude attenuation rate of the vibration arm after application of heat;
[0057] FIG. 13 is a diagram showing a relationship between a ratio of a withstanding voltage of the PZT thin film with respect to the coercive electric field and a polarization temperature;
[0058] FIG. 14 is a diagram showing a relationship between a ratio of the polarization temperature in the polarization processing with respect to the Curie temperature ( 1/16 to 5/4-times the Curie temperature T c ) and the amplitude attenuation rate after application of heat;
[0059] FIG. 15 is a diagram showing relationships of a ratio of a prebake temperature with respect to the Curie temperature (½ to 5/4 the Curie temperature T c ), with the amplitude attenuation rate after application of heat and a post-baking/post-polarization amplitude attenuation rate;
[0060] FIG. 16 is a plan diagram showing an angular velocity sensor according to a second embodiment;
[0061] FIG. 17 is a schematic diagram of the angular velocity sensor shown in FIG. 16 ; and
[0062] FIG. 18 is a cross-sectional diagram taken along the line A-A of FIG. 16 .
DETAILED DESCRIPTION
[0063] An embodiment will be described with reference to the drawings.
First Embodiment
[0064] A first embodiment will be described. FIGS. 1 are diagrams showing a piezoelectric device and an angular velocity sensor including the piezoelectric device according to the first embodiment.
[0065] An angular velocity sensor 31 includes a base body 130 and a vibration arm 132 that extends from the base body 130 and is capable of vibrating. FIG. 1B is a cross-sectional diagram of a surface vertical to a longitudinal axis (Z axis) of the vibration arm 132 .
[0066] The angular velocity sensor 31 includes a semiconductor arm base 133 made of, for example, silicon, and a piezoelectric device 139 disposed on the arm base 133 . As shown in FIG. 1B , for example, a first electrode film 34 a as a common electrode is laminated on a silicon substrate, and a piezoelectric film 33 is laminated on the first electrode film 34 a . On a first surface 33 a as an upper surface of the piezoelectric film 33 , a second electrode film 34 b , a first detection electrode 34 c , and a second detection electrode 34 d each having a predetermined elongated shape are formed.
[0067] Also on the base body 130 , a lead electrode including lead wires 136 , electrode pads 138 , bumps 134 a to 134 d , and the like is formed. The bump 134 a is connected to the second electrode film 34 b , the bumps 134 b and 134 c are respectively connected to the first detection electrode 34 c and the second detection electrode 34 d , and the bump 134 d is connected to the first electrode film 34 a . An external connection to a control circuit (not shown) such as an IC is made via the bumps 134 a to 134 d . The bumps 134 a to 134 d are each formed of metal, for example, but are not limited thereto.
[0068] After the first electrode film 34 a , the second electrode film 34 b , the first detection electrode 34 c , the second detection electrode 34 d , the lead wires 136 , and the like are formed as described above, the angular velocity sensor 31 of a shape as shown in FIG. 1A is cut out from a silicon wafer.
[0069] Next, a typical example of an operation of the angular velocity sensor 31 will be described.
[0070] The first electrode film 34 a of the piezoelectric device 139 is connected to a DC power supply, and an AC power supply is connected between a first electrode film 34 a and the second electrode film 34 b . Accordingly, a voltage is applied to the piezoelectric film 33 disposed between the first electrode film 34 a and the second electrode film 34 b so that the vibration arm 132 is caused of a flexion movement in a vertical direction (Y direction).
[0071] When an angular velocity ω 0 is applied to the vibration arm 132 during the flexion movement, Coriolis force is generated in the vibration arm 132 . The Coriolis force is generated in a direction vertical (X direction) to a direction of the flexion movement of the vibration arm 132 (Y direction), a magnitude of which is proportional to a value of the applied angular velocity ω 0 . The Coriolis force is converted into an electric signal by the piezoelectric film 33 , and the converted signal is detected by the first detection electrode 34 c and the second detection electrode 34 d.
[0072] Next, piezoelectric performance and heat resistance performance of the piezoelectric device 139 will be described while describing a method of manufacturing the angular velocity sensor 31 . It should be noted that descriptions will mainly be given on a method of forming the piezoelectric device 139 formed on the arm base 133 .
[0073] First, a silicon wafer is prepared. An oxidation protection film may be formed on the silicon wafer by thermal oxidation processing.
[0074] The first electrode film 34 a is formed by depositing Ti of 30 nm on the silicon wafer by a sputtering method, and then depositing Pt of 100 nm thereon, for example. The deposition method of the first electrode film 34 a is not limited to the sputtering method, and a vacuum vapor deposition method or other deposition methods may be used. Moreover, the metal materials that constitute the first electrode film 34 a are not limited to Ti and Pt, and examples thereof include Ir, Au, and Ru, or oxides of Ti, Pt, Ir, Au, and Ru. The second electrode film 34 b may also be constituted of those metal materials.
[0075] Subsequently, the piezoelectric film 33 is formed by forming a PZT thin film on the first electrode film 34 a by, for example, the sputtering method. The deposition method of the piezoelectric film 33 is not limited to the sputtering method, and deposition methods such as a vacuum vapor deposition method, a PLD (pulsed laser deposition) method, a sol-gel method, an aerosol deposition method, and the like may be used. A substrate temperature when depositing the PZT thin film 33 may either be at room temperature or at a high temperature.
[0076] In the deposition of the PZT thin film 33 , a PbO excessive composition ratio X is set to be −0.1 or more and 0.5 or less, and a Zr composition ratio Y is set to be 0.35 or more and 0.65 or less. For realizing such a PZT composition ratio, a target composition, sputtering conditions, annealing conditions, and the like are set appropriately. For increasing a perovskite structure of the PZT after the PZT thin film 33 is formed on the first electrode film 34 a , heating processing at 700°, for example, may be carried out on the PZT thin film 33 . A crystalline structure of the PZT thin film 33 in this case is tetragonal.
[0077] A film thickness of the PZT thin film 33 formed as described above is 100 nm to 1,400 nm.
[0078] After the PZT thin film 33 is formed, Pt of 200 nm is deposited on the PZT thin film 33 by the sputtering method to thus form the second electrode film 34 b . The deposition method of the second electrode film 34 b in this case is not limited to the sputtering method, and a vacuum vapor deposition method or other deposition methods may be used.
[0079] Next, a voltage is applied between the first electrode film 34 a and the second electrode film 34 b in an atmosphere heated to 240°, and polarization processing is carried out on the PZT thin film 33 . The voltage applied between the first electrode film 34 a and the second electrode film 34 b is 1 to 20-times as large as a coercive electric field E c . Moreover, a polarization temperature in the polarization processing is, compared to a Curie temperature, 1/16 to 5/4 the Curie temperature. It should be noted that the polarization processing may be carried out in any of an atmosphere, an oxygen atmosphere, and a nitrogen atmosphere.
[0080] After the polarization processing, prebake processing is carried out on the deposited PZT thin film 33 . A prebake temperature of the prebake processing is ½ to 5/4 the Curie temperature.
[0081] The PZT thin film 33 described above may have a tension stress. For providing the tension stress to the PZT thin film 33 , the PZT thin film 33 may be subjected to heating processing at, for example, 650° C. to 750° C. after being formed on the first electrode film 34 a . Accordingly, crystallization of the PZT thin film 33 is accelerated, thus obtaining the tension stress. In addition, in this case, the target composition, the sputtering conditions, the annealing conditions, and the like are set appropriately such that the PbO excessive composition ratio X of the PZT becomes 0.04, the Zr composition ratio Y thereof becomes 0.35 to 0.65, and the tension stress becomes −100 MPa to 600 MPa, for example.
[0082] Further, the first electrode film 34 a described above may also have the tension stress. For providing the tension stress to the first electrode film 34 a , the first electrode film 34 a may be subjected to the heating processing at, for example, 100° C. to 800° C. after the PZT thin film 33 is formed thereon. Alternatively, it is also possible to provide the tension stress to the first electrode film 34 a by the heating processing carried out during deposition instead of after the deposition of the first electrode film 34 a and the PZT thin film 33 . By changing deposition conditions, heating processing conditions, and the like, a tension stress of a wide range can be provided to the first electrode film 34 a . The tension stress of the first electrode film 34 a formed as described above is −200 MPa to 2,000 MPa.
[0083] (Evaluation of Piezoelectric Characteristics)
[0084] Next, descriptions will be given on piezoelectric characteristics of the piezoelectric device 139 thus formed on the silicon wafer.
[0085] FIG. 2 is a diagram showing an XRD (X-ray diffraction) pattern of the PZT thin film 33 . The PZT is oriented to a <111> surface and has an orientation degree of 97%. In FIG. 2 , the film thickness of the PZT thin film 33 whose XRD pattern has been measured is 900 nm, the voltage used in the polarization processing is 6-times the coercive electric field, and the polarization temperature is 240° C. In addition, the prebake temperature is 200° C. for 100 s.
[0086] It should be noted that in the following descriptions made on the figures, unless specified otherwise, the film thickness of the PZT thin film 33 is 900 nm.
[0087] FIG. 3 is a diagram showing a relationship between the film thickness (100 nm to 1,400 nm) of the PZT thin film 33 and a piezoelectric constant d31. As shown in FIG. 3 , the PZT thin film 33 shows favorable piezoelectric characteristics when the film thickness is 400 nm to 1,000 nm. Consequently, piezoelectric characteristics sufficient for the piezoelectric device 139 of the angular velocity sensor 31 can be obtained when the film thickness is within the range of 400 nm to 1,000 nm.
[0088] The piezoelectric constant d31 decreases when the film thickness of the PZT thin film 33 is 1,000 nm or more. This is probably because when the film thickness is 1,000 nm or more, crystals grow in a direction other than the <111> surface direction, such as a <001> surface direction, and thus a peak intensity in the <111> surface direction is saturated. Therefore, by setting the film thickness of the PZT thin film 33 to be less than 1,000 nm, peak growths in directions other than the <111> surface direction can be suppressed. It should be noted that a main peak of a crystal mainly contributes to the piezoelectric characteristics.
[0089] Meanwhile, the film thickness of less than 400 nm leads to an increase in leak current, whereby it becomes difficult to obtain piezoelectric characteristics sufficient for the piezoelectric device 139 .
[0090] FIG. 4 is a diagram showing relationships of the PbO excessive composition ratio X (−0.1 to 0.5) of the PZT thin film 33 with the piezoelectric constant d31 and a loss rate tan δ. The orientation degree of the PZT thin film 33 in the <111> surface direction is 80% or more and less than 100%, and the Zr composition ratio Y is 0.5.
[0091] It can be seen from FIG. 4 that the piezoelectric constant d31 and the loss rate tan δ are both favorable when the PbO excessive composition ratio X is within the range of 0 to 0.3. The piezoelectric characteristics deteriorate when the PbO excessive composition ratio X is less than 0. This is probably because PZT crystallinity deteriorates when the PbO excessive composition ratio X is small. On the other hand, the loss rate tan δ increases and the piezoelectric characteristics deteriorate when the PbO excessive composition ratio X is 0.3 or more. This is probably because an insulation property of the PZT thin film 33 deteriorates when the PbO excessive composition ratio X is large, thus resulting in a decrease in piezoelectric characteristics.
[0092] FIG. 5 is a diagram showing a relationship between the Zr composition ratio Y (0.35 to 0.65) of the PZT thin film 33 and the piezoelectric constant d31. As shown in FIG. 5 , the PZT thin film 33 shows maximum piezoelectric characteristics when the Zr composition ratio Y is 0.51 and favorable piezoelectric characteristics when the Zr composition ratio Y is 0.4 or more and 0.55 or less. As long as the Zr composition ratio Y is 0.4 or more and 0.55 or less, piezoelectric characteristics sufficient for the piezoelectric device 139 of the angular velocity sensor 31 can be obtained.
[0093] Incidentally, it is known that a bulk PZT shows favorable piezoelectric characteristics when the Zr composition ratio Y thereof is 0.5 or more and 0.53 or less. However, the piezoelectric characteristics of the bulk PZT deteriorate precipitously when the Zr composition ratio Y becomes less than 0.5. On the other hand, as shown in FIG. 5 , the PZT thin film deposited by, for example, the sputtering method shows favorable piezoelectric characteristics even when the Zr composition ratio Y is 0.4 or more and 0.5 or less.
[0094] (Evaluation of Heat Resistance)
[0095] Next, an evaluation on the heat resistance will be described, but first, descriptions will be given on a method of evaluating heat resistance.
[0096] The angular velocity sensor 31 of a shape as shown in FIG. 1A is cut out from the silicon wafer on which the piezoelectric device 139 including the first electrode film 34 a , the PZT thin film 33 , and second electrode film 34 b , the lead wires 136 , and the like are formed. An MEMS (Micro Electro Mechanical Systems) technique is typically used for the cutout from the silicon wafer. It should be noted that length, width, and thickness of the vibration arm 132 are, for example, 2,000 μm, 150 μm, and 150 μm, respectively.
[0097] The heat resistance is evaluated by measuring an amplitude of the vibration arm 132 of the thus-formed angular velocity sensor 31 in the Y direction. Specifically, the heat resistance of the piezoelectric device 139 is evaluated by measuring the amplitude of the vibration arm 132 in the Y direction, applying to the PZT thin film 33 heat that takes into account the heating processing carried out at the time of manufacturing the device, such as solder reflow, and re-measuring the amplitude of the vibration arm 132 in the Y direction thereafter. It should be noted that the heat applied to the PZT thin film 33 is, considering the heating processing at the time of manufacturing the device, 180° C. to 300° C., and a heating time thereof is 30 s to 300 s. In addition, the voltage applied between the first electrode film 34 a and second electrode film 34 b is an AC voltage of, for example, 1 kHz, 1V.
[0098] FIG. 6 is a diagram showing a relationship between the Zr composition ratio Y (0.35 to 0.7) of the PZT thin film 33 and an attenuation rate of the vibration arm 132 after application of heat. The heating temperature and the heating time are 240° C. and 90 s, respectively.
[0099] It can be seen from FIG. 6 that attenuation of the amplitude of the vibration arm 132 after application of heat increases when the Zr composition ratio Y exceeds 0.55, whereas the attenuation thereof is hardly observed when the Zr composition ratio Y is 0.55 or less. In other words, the PZT thin film 33 with the Zr composition ratio Y of 0.55 or less has excellent heat resistance.
[0100] FIG. 7 is a diagram showing a relationship between the heating time and the amplitude attenuation rate after application of heat in a case where the heating temperature is set to 240°. The Zr composition ratio Y of the PZT thin film 33 is within the range of 0.35 to 0.60. It can be seen from FIG. 7 that when the Zr composition ratio Y is 0.55 or less, the amplitude attenuation after application of heat hardly occurs even when the heating time is extended, which implies excellent heat resistance.
[0101] FIG. 8 is a diagram showing a relationship between the heating temperature and the amplitude attenuation rate after application of heat. The Zr composition ratio Y of the PZT thin film 33 is within the range of 0.35 to 0.60. It can be seen from FIG. 8 that when the Zr composition ratio Y is 0.55 or less, the amplitude attenuation after application of heat hardly occurs even when the heating temperature is increased, which implies excellent heat resistance.
[0102] FIG. 9 is a diagram showing a relationship between a stress (−100 MPa to 600 MPa) of the PZT thin film 33 and the amplitude attenuation rate after application of heat. In this case, the tension stress of the first electrode film 34 a is 1,000 MPa. In addition, the heating temperature and heating time of the PZT thin film 33 are 240° C. and 90 s, respectively. It should be noted that in FIG. 9 , a stress of a positive value represents a tension stress, and a stress of a negative value represents a compression stress.
[0103] Now, a method of measuring a stress of the PZT thin film 33 will be described. An X-ray reciprocal lattice map measurement method is used as the method of measuring a stress of the PZT thin film 33 , and an X-ray diffraction apparatus X'pert PRO MRD (registered trademark) from PANalytical (registered trademark) is used as a measurement apparatus therefor. In the reciprocal lattice map technique, a measurement target sample is tilted about a φ axis orthogonal to a θ axis, and diffraction from a crystal surface of the sample is detected. Identification of the measurement target sample is made based on the detected diffraction peak.
[0104] For example, in a case where there is no distortion or stress in the crystal of the measurement target sample, no change in diffraction angle occurs at any φ angle regarding a main orientation peak of the PZT <111> diffraction (in the vicinity of (2θ, φ)=(38°, 0°), (2θ, φ)=(38°, 70°)). However, in a case where there is a tension stress in the measurement target sample, the diffraction angle when φ=70° shifts more on a low-angle side than the diffraction angle when φ=0. On the other hand, in a case where there is a compression stress in the measurement target sample, the diffraction angle when φ=70° shifts more on a wide-angle side than the diffraction angle when φ=0. By evaluating a magnitude of the shift, it is possible to measure the stress of the PZT thin film 33 .
[0105] The method of measuring a stress of the PZT thin film 33 is not limited to the X-ray reciprocal lattice map measurement method, and other methods may be used instead. For example, as described in the following reference, a value of the stress may be evaluated by using Stoney Expression after measuring a warpage of a substrate on which a film is deposited (reference: “Basics and Application of Thin Films by a Plasma Process”, Hiroshi Ichimura, Masaru Ikenaga, THE NIKKAN KOGYO SHIMBUN, LTD., 2005). For measuring Young's modulus necessary for derivation of a stress, a nanoindentation method is used as described in the reference, for example. The X-ray reciprocal lattice map measurement method, the measurement method described in the reference, or the like is also used as a measurement method of the first electrode film 34 a to be described later.
[0106] As shown in FIG. 9 , the amplitude after application of heat is not attenuated when the tension stress of the PZT thin film 33 is 50 MPa or more and 500 MPa or less. In other words, the PZT thin film 33 with the tension stress of 50 MPa to 500 MPa has favorable heat resistance. In particular, the PZT thin film 33 with the tension stress of 100 MPa to 300 MPa has favorable heat resistance.
[0107] The reason why the PZT thin film 33 has favorable heat resistance when provided with the tension stress that is within the range described above is that a crystal lattice of the PZT is distorted to thus suppress a movement of domains.
[0108] As shown in FIG. 9 , the amplitude after application of heat is attenuated when the tension stress of the PZT thin film 33 exceeds 500 MPa. This is probably because cracks increase due to the stress of the PZT thin film 33 , and the distortion of the crystal lattice is thus eliminated. On the other hand, the amplitude after application of heat is attenuated when the tension stress is less than 50 MPa. This is probably because the movement of domains is facilitated since there is no distortion in crystal lattice due to a low stress of the PZT thin film 33 .
[0109] FIG. 10 is a diagram showing a relationship between a stress (−500 MPa to 2,000 MPa) of the first electrode film 34 a and the amplitude attenuation rate after application of heat. In this case, the tension stress of the PZT thin film 33 is 200 MPa. In addition, the heating temperature and heating time of the PZT thin film 33 are 240° C. and 90 s, respectively.
[0110] As shown in FIG. 10 , the amplitude after application of heat is not attenuated when the tension stress of the first electrode film 34 a is 500 MPa or more and 1,500 MPa or less. In other words, it can be seen that the piezoelectric device 139 including the first electrode film 34 a with the tension stress of 500 MPa to 1,500 MPa has favorable heat resistance. In particular, it can be seen that when the first electrode film 34 a has a tension stress of 700 MPa to 1,200 MPa, the PZT thin film 33 formed on the first electrode film 34 a has favorable heat resistance.
[0111] The reason why the piezoelectric device 139 has favorable heat resistance when the first electrode film 34 a is provided with the tension stress that is within the range described above is that a crystal lattice of the PZT thin film 33 is distorted to an appropriate degree by the tension stress of the first electrode film 34 a , to thus suppress the movement of domains.
[0112] The amplitude after application of heat is attenuated when the tension stress of the first electrode film 34 a exceeds 1,500 MPa. This is probably because cracks of the PZT thin film 33 increase by the tension stress of first electrode film 34 a , and the distortion of the crystal lattice is thus eliminated. In this case, cracks have actually been observed on the surface of the PZT thin film 33 . Moreover, a peeling has been observed between the first electrode film 34 a having the tension stress of more than 1,500 MPa and the arm base 133 .
[0113] On the other hand, the amplitude after application of heat is attenuated also when the tension stress of the first electrode film 34 a is less than 500 MPa. This is probably because the movement of domains is facilitated since there is no distortion in crystal lattice due to a low stress of the first electrode film 34 a.
[0114] FIG. 11 is a diagram showing a relationship between an orientation degree of the PZT in the <111> surface direction and the amplitude attenuation rate of the vibration arm 132 after application of heat. The PbO excessive composition ratio X and Zr composition ratio Y of the PZT thin film 33 are 0.04 and 0.48, respectively. It can be seen from FIG. 11 that when the orientation degree of the PZT in the <111> surface direction is 80% or more, the amplitude attenuation after application of heat hardly occurs, which implies excellent heat resistance. On the other hand, it can be seen that when the orientation degree of the PZT in the <111> surface direction is less than 80%, the amplitude attenuation after application of heat is apt to occur.
[0115] Next, descriptions will be given on relationships of the amplitude attenuation rate of the vibration arm 132 after application of heat with polarization processing conditions and prebake conditions. It should be noted that in FIGS. 12 to 15 in descriptions below, the PbO excessive composition ratio X and Zr composition ratio Y of the PZT thin film 33 are 0.04 and 0.48, respectively. Moreover, the heating temperature and heating time of the PZT thin film 33 are 240° C. and 90 s, respectively.
[0116] FIG. 12 is a diagram showing a relationship between a ratio of a polarization voltage in the polarization processing with respect to a coercive electric field (1 to 20-times the coercive electric field E c ) and the amplitude attenuation rate of the vibration arm 132 after application of heat. As shown in FIG. 12 , the amplitude attenuation after application of heat hardly occurs when the polarization voltage is 2 to 20-times the coercive electric field E c , which implies excellent heat resistance. FIG. 13 shows a relationship between a ratio of a withstanding voltage of the PZT thin film 33 with respect to the coercive electric field and the polarization temperature. As shown in FIG. 13 , an increase in polarization temperature leads to a decrease in ratio of the withstanding voltage of the PZT with respect to the coercive electric field. A dielectric breakdown of the PZT occurs when a polarization voltage that is 20-times or more the coercive electric field is applied to the PZT at the polarization temperature of 180° C. or more. Therefore, it can be seen that applying the polarization voltage that is 20-times or more the coercive electric field E c to the PZT is inappropriate, and an appropriate polarization voltage is a voltage that is 2 to 20-times the coercive electric field E c .
[0117] FIG. 14 is a diagram showing a relationship between a ratio of the polarization temperature in the polarization processing with respect to a Curie temperature ( 1/16 to 5/4 the Curie temperature T c ) and the amplitude attenuation rate after application of heat. The polarization voltage is 6 -times the coercive electric field Ec. As shown in FIG. 14 , when the polarization temperature is ¼ or more and equal to or smaller than the Curie temperature T c , the amplitude attenuation after application of heat hardly occurs, which implies excellent heat resistance. The reason why the amplitude attenuation is large when the polarization temperature is less than ¼ the Curie temperature T c is probably because, due to insufficient polarization processing, the movement of domains of the PZT thin film 33 is suppressed. On the other hand, the reason why the amplitude attenuation is large when the polarization temperature exceeds the Curie temperature T c is probably because, due to a cubic crystalline structure of the PZT thin film 33 , the movement of domains is facilitated after the polarization processing.
[0118] FIG. 15 is a diagram showing relationships of a ratio of a prebake temperature Ta with respect to the Curie temperature (½ to 5/4 the Curie temperature T c ), with the amplitude attenuation rate after application of heat (abscissa axis and right-hand side ordinate axis) and a post-baking/post-polarization amplitude attenuation rate (abscissa axis and left-hand side ordinate axis).
[0119] Specifically, in FIG. 15 , the amplitude attenuation rate in the prebake processing is evaluated by measuring the amplitude of the vibration arm 132 after the polarization processing, and re-measuring the amplitude of the vibration arm 132 after the prebake processing (½ to 5/4 the Curie temperature T c ) (abscissa axis and left-hand side ordinate axis). After that, heat that takes into account the heating processing at the time of manufacturing the device is applied to the PZT thin film 33 that has been subjected to the prebake processing, the amplitude of the vibration arm 132 after application of heat is measured, and the amplitude attenuation rate after application of heat is thus measured (abscissa axis and right-hand side ordinate axis). It should be noted that the polarization voltage is 6 -times the coercive electric field E c , and the polarization temperature is 260° C.
[0120] As shown in FIG. 15 , it can be seen that when the prebake temperature Ta is ¾ or less the Curie temperature T c , the amplitude of the vibration arm 132 after the prebake processing is not attenuated as much as that after the polarization processing. Moreover, it can be seen that when the prebake temperature Ta is ¼ or more the Curie temperature T c , the amplitude after application of heat is not attenuated as much as that after the polarization processing, meaning that the piezoelectric device 139 has excellent heat resistance. Therefore, by setting the prebake temperature Ta in the prebake processing to be ¼ or more and ¾ or less the Curie temperature T c , it becomes possible to obtain a piezoelectric device 139 with excellent heat resistance.
Second Embodiment
[0121] Next, a second embodiment will be described.
[0122] FIG. 16 is a plan diagram showing an angular velocity sensor according to this embodiment. In addition, FIG. 17 is a schematic diagram of the angular velocity sensor according to this embodiment, and FIG. 18 is a cross-sectional diagram taken along the line A-A of FIG. 16 .
[0123] As shown in the figures, an angular velocity sensor 200 includes a base body 214 , an arm retention portion 215 provided on one side of the base body 214 , and a vibration arm portion 216 provided on a tip end side of the arm retention portion 215 .
[0124] The vibration arm portion 216 includes a first vibration arm 211 , and second and third vibration arms 212 and 213 sandwiching the first vibration arm 211 . The first vibration arm 211 is constituted of an arm base 210 a and a piezoelectric device 239 a formed thereon, the second vibration arm 212 is constituted of an arm base 210 b and a piezoelectric device 239 b formed thereon, and the third vibration arm 213 is constituted of an arm base 210 c and a piezoelectric device 239 c formed thereon. In other words, the angular velocity sensor 200 according to this embodiment is a so-called triple-branch tuning-fork type angular velocity sensor.
[0125] The first to third vibration arms 211 to 213 have the same width and thickness, for example. Moreover, a gap between the first and second vibration arms 211 and 212 and a gap between the first and third vibration arms 211 and 213 are the same.
[0126] As shown in FIG. 18 , first electrode films 221 to 223 are respectively formed on the arm bases 210 a to 210 c , and PZT thin films 231 to 233 each as a piezoelectric film are respectively formed on the first electrode films 221 to 223 . Further, second electrode films 241 to 243 each as a drive electrode are respectively formed on the PZT thin films 231 to 233 . Moreover, a first detection electrode 251 and a second detection electrode 252 are formed on the piezoelectric thin film 231 of the first vibration arm 211 in the middle of the vibration arm portion 216 .
[0127] A film thickness of each of the PZT thin films 231 to 233 and the PbO excessive composition ratio X and Zr composition ratio Y of the PZT are the same as that of the PZT thin film 33 according to the first embodiment. Further, the PZT thin films 231 to 233 each have a tension stress of the same level as the PZT thin film 33 . Furthermore, the first electrode films 221 to 223 also have a tension stress of the same level as the first electrode film 34 a of the first embodiment.
[0128] The plurality of electrodes 221 to 223 , 241 to 243 , 251 , and 252 included in the respective piezoelectric devices 239 are respectively connected to lead wires 261 to 268 . The lead wires 261 to 268 pass through a surface of the arm retention portion 215 to be respectively connected to lead terminals 271 to 278 provided on a surface of the base body 214 . The lead terminals 271 to 278 are provided four each on both sides in an X direction on the surface of the base body 214 .
[0129] Next, an operation of the angular velocity sensor 200 according to this embodiment will be described.
[0130] The first vibration arm 211 is caused of a flexion movement in the vertical direction of FIG. 18 when a voltage is applied to the first electrode film 221 and the second electrode film 241 . Meanwhile, the second and third vibration arms 212 and 213 are caused of a flexion movement in the vertical direction at a phase opposite to that of the first vibration arm 211 , when a voltage is applied to the first electrode films 222 and 223 and second electrode films 242 and 243 .
[0131] Specifically, the second and third vibration arms 212 and 213 move downward when the first vibration arm 211 move upward, and the second and third vibration arms 212 and 213 move upward when the first vibration arm 211 move downward. Moreover, by the second and third vibration arms 212 and 213 being caused of the flexion movement at an amplitude half the amplitude of the first vibration arm 211 , moments generated by the first to third vibration arms 211 to 213 are canceled out.
[0132] As a result of evaluating the piezoelectric devices 239 of the thus-structured angular velocity sensor 200 in the same manner as in FIGS. 2 to 15 , it has been confirmed that each of the piezoelectric devices 239 has the same piezoelectric performance and heat resistance as the piezoelectric device 139 of the angular velocity sensor 31 according to the first embodiment.
[0133] It should be noted that although the second electrode films 241 to 243 for driving the respective vibration arms are provided to the respective vibration arms in this embodiment, it is also possible to form the second electrode film on only the first vibration arm 211 , for example. In this case, the second and third vibration arms 212 and 213 vibrate at phases opposite to that of the first vibration arm 211 by a counteraction of the vibration of the first vibration arm 211 .
[0134] Alternatively, it is also possible to form the second electrode films on only the second and third vibration arms 212 and 213 . In this case, the first vibration arm 211 vibrates at a phase opposite to that of the second and third vibration arms 212 and 213 by a counteraction of the vibration of the second and third vibration arms 212 and 213 .
[0135] The piezoelectric device and angular velocity sensor described above are not limited to the above embodiments, and various modifications can be made.
[0136] For example, in the deposition of the PZT thin film 33 above, although the PZT is formed so as to have an orientation in the <111> surface direction, the present application is not limited thereto, and the PZT may be deposited so as to have an orientation in a <100> surface direction or a <001> surface direction. Even when the PZT is deposited as described above, a piezoelectric device 139 with excellent piezoelectric characteristics and heat resistance can still be obtained.
[0137] In the above embodiments, descriptions have been given on the case where the crystalline structure of the PZT thin film 33 is tetragonal. However, the crystalline structure of the PZT thin film 33 may be rhombohedral, pseudo tetragonal, pseudo rhombohedral, or the like. Moreover, the PZT thin film 33 may include at least one of additive elements selected from the group consisting of Cr, Mn, Fe, Ni, Mg, Sn, Cu, Ag, Nb, Sb, and N.
[0138] Instead of the angular velocity sensor 31 , the piezoelectric device 139 can also be applied to, for example, a pyroelectric infrared ray sensor, a liquid injection apparatus, a semiconductor storage apparatus, and the like. It should be noted that in this case, the piezoelectric device 139 only needs to be provided with at least one of the first and second electrode films, and the first and second detection electrodes do not necessarily need to be provided thereto.
[0139] The above embodiments respectively illustrate the so-called single-branch tuning-fork type angular velocity sensor 31 and triple-branch tuning-fork type angular velocity sensor 200 . However, the number of vibration arms may be 2 or more than 3. Alternatively, although the angular velocity sensors 31 and 200 each have a cantilever structure, the sensors may each have a center impeller structure.
[0140] It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims. | A piezoelectric device includes a piezoelectric film and an electrode film. The piezoelectric film is constituted of lead zirconium titanate represented by Pb 1+X (Zr Y Ti 1−Y )O 3+X , where X is 0 or more and 0.3 or less and Y is 0 or more and 0.55 or less, the piezoelectric film having a tension stress. The electrode film applies a voltage to the piezoelectric film. | 7 |
DESCRIPTION
The invention concerns an electrical reversing switch according to the specifications of patent claim 1.
Further applications have been found for plasma production in plants which deposit and strip thin films by using high frequency fields. The switches required for reversing the high frequency electrodes can transmit currents up to 50 A at typical frequencies of 13.56 MHz. These switches should be compact and have an open flash-over resistance of about 10 kV. The switch-over process is currentless.
The goal of the invention is to produce a switch of the above mentioned kind.
This problem is solved according to specifications of patent claim 1.
The particular advantage achieved by this invention is the large conducting surface which the surface current created by current displacement has at its disposal. In addition, the switch is self-locking, i.e. it is stable in every switch position. Compressed air is only required during the switching process, and the contacting surfaces clean themselves during switch-over.
A model example of this invention is depicted by the drawing and will be described in detail in the following.
The single figure shows a section through switch 1 according to the invention, which is made of a housing 2 composed of an insulating material, which contains a switching drum 3 with a mid-wall 4. This switching drum is supported on both sides by pilot cylinders 5, 6, of which one pilot cylinder, 5, is shown in cross section and the other pilot cylinder, 6, is drawn closed. In this example the pilot cylinders 5, 6 are solid and made of a synthetic material. Through each one of these cylinders passes one axial bore 7, going through an injection nozzle, 8, which is connected with its corresponding compressed air hose 9, 10. Both compressed air hoses 9, 10 are hooked up to a common pressure distributor 11, which is equipped with a mechanical reversing switch 12. A container with compressed air 13 is connected with the pressure distributor 11. The compressed air hoses 9, 10 have special injection nozzles 14, 15, which are fitted into the side wall of the housing 2. Fitted into the housing are also ring-shaped mountings 16, 17, 18, with multiple contact strips 19, 20, 21 on their inside-facing ends. When making an electric connection these contact strips lie against the outer wall of the switching drum 3. In the example shown both contact strips 19, 20 are in contact with the switching drum 3, while contact strip 21 is not. Thus, there exists an electric connection between the two strips 19, 20 and thus between the mountings 16, 17. If, for example, the mountings 16, 17, 18 are coupled with electric lines 22 thru 27, then, in the arrangement according to the figure, there is a connection between lines 22 and 23 or 25 and 26.
The invention makes it possible to change the electric connection depicted in the figure. To do this the compressed air lever 12 is swung to the right, such that the compressed air is supplied by hose 9 and bore 7 to the mid-wall 4. Due to the air pressure the switching drum then moves to the right guided by cylinders 5, 6. Once it arrives on the right side, it is no longer the contacting strips 19 and 20 but 20 and 21 which are electrically connected.
The switching drum 3 can be brough back to the position shown in the figure by swinging the lever 12 to the left. Thus, the switching drum moves like a free floating piston, for example, such as used in A.C. generators (DE-PS 26 24 283). | The invention concerns an electrical reversing switch, which is especially suited for switching of high-frequency electrodes. This switch has an over mounted pneumatic cylinder, which moves on pistons arranged on both sides, and thus produces electric contacts. | 7 |
FIELD OF THE INVENTION
This invention relates to fiber laser devices that are laser pumped via a cladding layer.
BACKGROUND OF THE INVENTION
Rare-earth-doped fiber lasers are finding a variety of uses especially in optical communication systems where they can be integrated effectively with fiber links, and active fiber devices such as erbium fiber amplifiers. Fiber lasers are typically laser pumped with inexpensive multi-mode lasers, such as GaAlAs, but have high power, single mode outputs. Fiber laser structures have relatively large active areas so that heating effects, known to be detrimental to the lifetime of other solid state laser structures, are largely absent. See e.g., L. Zenteno, "High-Power Double-Clad Fiber Lasers", Journal of Lightwave Technology, Vol. 11, No. 9, pp. 1435-1446, September 1993.
It is known that the power of fiber lasers scales well with cavity length. However, intrinsic losses in the host fiber material also scale with length, and these losses can vary (increase) over time giving unstable system performance. An attractive alternative for increasing power would appear to be to increase the active core area by increasing the core diameter thus increasing the pump absorbing area for a given fiber length. However, for single mode output, this option requires a low core Δ. In a preferred structure, a threshold level of germanium dopant is desired in order to write Bragg gratings in the fiber core and thereby create a laser cavity. It is also known that dopants such as aluminum aid in solubilizing the active rare earth ions. Without an effective amount of Al for this function, the rare earth dopants crystallize, resulting in excessive scattering losses. However, both of these additives increase the core Δ. To keep the overall level of index-modifying dopants low enough to satisfy the low core Δ requirement mentioned above, the concentration of germanium and aluminum may be too low to meet the above mentioned goals. An approach that would accommodate these conflicting requirements and allow an increase in the active core diameter would represent a significant advance in this technology.
STATEMEMT OF THE INVENTION
A core composition for a fiber laser has been developed which allows a relatively large amount of mixed index-modifying dopants to be incorporated into the core but with a combined effect on the core index that is substantially less than the index-modifying effect of the individual ingredients taken alone. This discovery allows the core diameter of the fiber laser to be increased significantly. The synergistic result is obtained using phosphorus as a counterdopant to offset the index-modifying effect of at least one of the essential ingredients, in this case aluminum.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic representation of a fiber laser device; and
FIG. 2 is an end view of the fiber in the laser device of FIG. 1.
DETAILED DESCRIPTION
Referring to FIG. 1, a typical fiber laser structure is shown with optical fiber coil 11, with a portion of the coil cut away to depict substantial length. The length of the fiber in these structures is usually of the order of tens of meters, so the fiber in the figure represents many turns. The fiber can be supported on a variety of mandrel structures which may be round or oval. In principal, because it is end-pumped as shown, it can be strung out over its length or substantial portions of its length.
The laser cavity is formed by Bragg reflectors 12 and 13, shown here at the ends of the coiled fiber. These reflectors, or gratings, are typically produced by photoinducing refractive index changes in the core of the optical fiber. Preferably the core is appropriately sensitized with e.g. a hydrogen soak prior to writing the grating. The desired grating pattern is formed by using actinic radiation (typically an excimer laser--pumped frequency doubled dye laser operating near 240 nm) with a varying intensity or periodicity along the length of the fiber. This is conveniently done using a photomask, or by using a patterned light beam produced, e.g., by an interference pattern. The refractive index changes are produced typically by UV induced changes at defect sites of an absorbing ion such as germanium. The germanium doped fiber may be sensitized by hydrogen or deuterium treatments known in the art. Very large (>0.01) refractive index changes can be obtained in such a process. These techniques for forming optical gratings are well known in the art and are described in e.g. U.S. Pat. No. 4,725,110, issued Feb. 16, 1988 and 5,327,515, issued Jul. 5, 1994.
Referring again to FIG. 1, the fiber laser is end pumped by laser diode 14. The output of the fiber laser is indicated at 15. It will be evident to those skilled that the figures in this description are not drawn to scale, and the elements are schematically shown. For example, the laser diode is shown separate from the fiber but those skilled in the art recognize that typically the fiber is attached to the laser with a suitable coupler not shown.
Referring to FIG. 2, an end of the fiber laser is shown. This view is also representative of a cross section taken at any position along the fiber. The fiber laser comprises a core 21, a first cladding 22, and a second cladding 23. The fiber is shown with a circular cross section but may be non-circular, i.e. slightly elliptical, to allow mode coupling. The core of the fiber has a composition in accordance with the invention as will be described below. The first cladding layer is preferably a high silica material, preferably pure SiO 2 but at least 85% SiO 2 . If desired the first cladding layer can include dopants, e.g. germanium, aluminum or phosphorus, to increase the refractive index of the cladding and reduce the Δ between the cladding and the core. In principle, this eases the constraints discussed earlier, i.e. the core can be more heavily doped while still retaining the overall core/clad guiding characteristics desired. However, it is preferable to reduce the Δ using the technique of the invention because suitably doped cladding material with sufficient purity is not commercially available.
The second cladding 23 may be any suitable cladding material capable of confining the pump radiation in the first cladding layer, i.e. having a significant Δ with the first cladding layer. A significant Δ in this context is >0.03. A preferred second cladding layer is one of many well known polymer coating materials, doped with fluorine to yield the requisite Δ. An advantage of this choice is that the second cladding layer also can also serve as the primary fiber coating. Examples of a suitable materials are UV-curable fluorinated acrylates.
The dimensions of the structure shown in FIG. 2 may vary substantially. The first cladding layer is typically in the range 50-400 μm, and preferably 100-300 μm. The second cladding layer thickness may range from 10 μm to several hundred μm. For light guiding purposes the layer can be relatively thin. If the second cladding layer also serves as the primary or the sole coating, a substantially greater thickness will generally be desired.
The diameter of the core is the focus of the invention. A core size that is commonly used in commercial practice is of the order of 6 μm. For ease and low loss in interconnecting the fiber laser to standard input/output fiber links, or to other fiber devices, it is important that the core diameters closely match. However, in a typical fiber laser with a typical core composition which allows for UV writing of gratings, the core may be substantially smaller than 6 μm. For example, a typical fiber laser core has the following composition (constituents are expressed in terms of optical index):
Yb +3 : Δn=0.001
Al: Δn=0.004
Ge: Δn=0.004
total: Δn=0.009
Ytterbium is included at a concentration sufficient to absorb enough pump radiation to provide the desired output power level. This concentration will exhibit about 150 dB/m absorption at 915 nm. Aluminum is included to solubilize the ytterbium. Germanium is included in an amount sufficient to write Bragg gratings.
For single mode operation at 1060 μm, the core size for this fiber laser would have to be 4.7 μm. In a 200 μm overall diameter fiber the length of the fiber laser would be greater than 100 m.
According to the invention, the core of the fiber laser is counterdoped with phosphorus. Phosphorus counteracts the index-modifying effect of aluminum, and consequently can be incorporated in the core at levels sufficient for solubilizing the rare earth ions without substantially increasing the core Δ. The objective in general is to produce a core Δ of less than 0.007 (based on pure silica as the first cladding material), using the index compensation technique just described. The following core compositions are given by way of example of the invention. In each case the host material is silica, and the core Δ is calculated based on silica as the first cladding layer.
______________________________________constituent mole % Δn______________________________________Yb.sup.+3 0.5 .002Al 5.7 .0054P 1.4 .0014Ge 0.4 .0006______________________________________ Δn = .0066
The net contribution to Δn from the combined Al and P constituents is 0.004 since they offset one another. This fiber had a core diameter of 5.0 μm and cutoff wavelength <950 nm. The inner cladding was 200 μm in diameter and showed 0.18 dB/m absorption at 915 nm. The device length was approximately 70 m. These properties are desirable except that the Ge concentration for the device in this example is too low for strong gratings to be written. Increasing the Ge concentration to 1.5% to accommodate written gratings, while keeping other concentrations the same would result in a device length of approximately 110 m.
In the following example the Ge concentration has been increased to allow gratings to be written in the device, and the concentrations of Al and P are balanced to exactly offset their contribution to Δn.
______________________________________constituent mole % Δn______________________________________Yb.sup.+3 0.5 .002Al 4.3 .004P 4.3 .004Ge 1.5 .0022______________________________________ Δn = .0042
The core diameter of this fiber is 6.2 μm and cutoff wavelength <950 nm. The 200 μm cladding has an absorption of 0.28 dB/m, and the device length is approximately 45 m, substantially reduced from the device of Example I. Gratings can easily be written in this fiber. However, it was found that in drawing fibers with this composition the drawing conditions must be carefully controlled to avoid crystallization.
______________________________________constituent mole % Δn______________________________________Yb.sup.+3 0.5 .002Al 5.7 .0054P 8.6 .0081Ge 1.5 .0022______________________________________ Δn = .0069
The core diameter in this device was 5.1 μm and cutoff wavelength <950 nm. The 200 μm cladding had an absorption of 0.2 dB/m, and the device length is approximately 66 m. This fiber structure has strong grating writing capabilities, and is easily drawn without crystallization.
The rare earth used in most of these examples, and the preferred rare earth for the invention, is ytterbium, and the output wavelength is 1060 nm. Other rare earths, e.g., Ho, Nd, Er, Tm, Dy, may be substituted in whole or part. The ion concentration will vary depending on the absorption level of the pump radiation used, but is typically 0.1-3.0 mole %, usually 0.1-2.0 mole %. The quantity of aluminum needed to solubilize the rare earth in these compositions is in the range 0.5-8.0 mole %, and the amount of phosphorus added to counteract the index-modifying effect of the aluminum is in the range, 0.5-8.0 mole %. For effective writing of Bragg gratings the amount of germanium required is generally in the range 0.2-3.0%. Fibers with these core dopants are produced following well established methods by mixing the ingredients in the form of their oxides during manufacture of the fiber preform.
In addition to the constraints given above for the ranges of ingredients, the overall index variation, i.e. the core Δ, should be minimized to achieve the goal of the invention. The combined mole % of the dopants should be consistent with producing an overall index difference between the core and the first cladding layer of less than 0.008, and preferably less than 0.0072.
The pump diode used in these demonstrations was a relatively broad band GaAlAs device. However, other semiconductor laser pump sources such as InGaAs or InGaAsP can be substituted. Semiconductor pump lasers are preferred but other pump sources, e.g. Nd-glass, Ti-sapphire, can be used.
The fiber laser devices in these examples had fiber core diameters of approximately 6 μm. Although this is less than 30% larger than the core diameter of the prior art structure described, the difference is more than 60% in terms of the effective area of the core that is exposed to pump radiation. Therefore for a given output power, the length of this fiber laser can be less than half the length of the corresponding prior art fiber laser. Moreover, the flux on the Bragg gratings is reduced by the same area factor, thus reducing the potential for damage of the reflectors during the device lifetime. Using the teachings of the invention it will be routinely possible to produce fiber lasers with cores that essentially match the common fiber core diameters, i.e. 5.5 μm to 7.5 μm.
In Example II above the aluminum and phosphorus ingredients were used in equal amounts, i.e. amounts appropriate to largely offset the index-modifying effects of each ion and minimize the core Δ. It was found in the course of this work that when equal molar amounts of Al and P were used, which would appear to be the most effective approach for minimizing core Δ, the rare earth constituent tended to crystallize. Upon further investigation it was determined that solubilization of the rare earth ingredient is more effective if an excess of either aluminum or phosphorus is used. Therefore it will be noticed that in Examples I and III above, the molar amounts of aluminum and phosphorus are not the same. The excess of one over the other should be in the range 5-75% and preferably in the range of 5-50% .
It was also discovered in the course of this work that aluminum is somewhat more effective in solubilizing the rare earth ingredient. Accordingly, the preferred compositions are those which in which the molar quantity of Al present is from 5-75% or preferably 5-50% greater than the amount of P. On the other hand, in applications in which high levels of ionizing radiation and high optical power levels are experienced it may be beneficial to have high phosphorus levels, and a phosphorus rich composition may be desirable.
The fiber laser structures described in this work are dual clad designs which facilitate end or cladding pumping. Single clad structures, which may also be side pumped, are also known in the art and could benefit from the teachings set forth above. The term cladding layer in the context of the invention means a layer that performs some light guiding function. In the dual clad structures described above the second cladding layer also functions as a protective layer, and in performing this function may be referred to as a fiber coating. However, dual cladding fiber laser structures of the kind described above may also have a coating in addition to the second cladding layer.
Various additional modifications of this invention will occur to those skilled in the art. All deviations from the specific teachings of this specification that basically rely on the principles and their equivalents through which the art has been advanced are properly considered within the scope of the invention as described and claimed. | The specification describes fiber laser devices with cores containing aluminum in which the composition of the core is modified to minimize the core Δ, thereby allowing a larger core diameter, and a reduction in the fiber laser length by a factor equal to the square of the diameter difference. This result is achieved by compensation doping the core with phosphorus to offset the index-modifying contribution of aluminum. | 2 |
FIELD OF THE INVENTION
This invention relates to a phase control mechanism for controlling a predetermined phase relationship of at least one output.
BACKGOUND AND SUMMARY OF THE INVENTION
Many situations exist in industry and transport where it is necessary to be able to alter the phase relationship between concentric rotating shafts, parallel shafts or other similar elements while they are in motion and under load.
Examples of this need, include the control of the pitch of propellers of aircraft and boats, particularly ships; controlling the pitch of power producing windmills; opening and closing lathe and drill chucks while they are in motion during production runs; controlling the eccentricity of some forms of continuously variable transmissions and determining the valve timing of cam shafts in internal combustion engines.
Operations of the type mentioned above is usually achieved by using electric devices or sliding mechanical mechanisms. These mechanisms all have difficulty with high levels of torque, and in general, with reliability.
A need therefore exists for a mechanical rotating mechanism which is able to alter the phase relationship between two or more concentric or parallel shafts while they are in motion and under load.
The invention may be said to reside in a phase control mechanism including:
an input for supplying input rotary power;
a plurality of outputs each for providing output rotary power;
a plurality of first gear members each coupled to a corresponding output of the plurality of outputs;
drive means for transmitting rotary power from the input to the outputs so that when the input is driven, power is supplied to the outputs for driving the outputs;
a phase adjusting means for causing the first gear members to advance or regress relative to one another; and
means for actuating the phase adjusting means to thereby cause the first gear members to advance or regress relative to one another to change the phase relationship between the outputs.
Thus, in order to change the phase relationship between the outputs the actuating means is moved to adjust the position of the adjusting means which in turn causes the first gear members to regress or advance relative to each other to change the phase relationship between the outputs. The phase between the outputs can therefore be adjusted to not only supply rotary power from the input to the outputs but also to alter the position of a device or article coupled on the outputs relative to one another. The phase relationship can be changed with the mechanism operating (that is supplying rotary power) or with the mechanism stationary. It is not necessary to stop the mechanism to change the phase relationship and therefore the phase relationship of the input and output can then be adjusted during operation as required.
In one embodiment of the invention the input is integral with a first of the output shafts and a second of the output shafts is mounted concentrically on the first output shaft, the drive means comprises:
in respect of the first output, the integral coupling of that output to the input, and
in respect of the second output comprises;
(a) a fixed spur gear having a first set of teeth which mesh with teeth of the first gear member on the first output, the fixed spur gear having a second set of teeth which mesh with teeth on an idler gear rotatable relative to the outputs;
a second spur gear which has a first set of teeth meshing with the idler gear and a second set of teeth meshing with the first gear member coupled to the second output; and
wherein said second spur gear is mounted in a yoke pivotal relative to the outputs and wherein the second spur gear forms said phase adjusting means and the yoke forms said actuating means so that when the yoke is pivoted relative to the input and output, the second spur gear is driven around the first gear on the second output and the idler gear to cause the first gear on the second output to regress or advance relative to the first gear on the first output to alter the phase relationship between the input and output.
In a second embodiment of the invention, the input has a cage which supports at least one pinion gear, the pinion gear engaging a first bevel gear mounted on first output and a second bevel gear mounted on a second output;
wherein said pinion gear and said first and second bevel gears form said drive means;
said first gear member coupled to the first output being arranged on said cage and being coupled to the first output by the cage, the pinion gear and the first bevel gear, the first gear member on the cage engaging a first set of teeth of a fixed spur gear, the fixed spur gear having a second set of teeth for engaging an idler gear rotatable relative to the outputs, a second spur gear mounted in a yoke pivotable relative to the outputs, the second spur gear having a first set of teeth engaging said idler gear and a second set of teeth engaging said first gear member coupled to the second shaft; and
wherein said second spur gear forms the phase adjusting means and wherein the yoke forms the actuating means so that upon pivoting movement of the yoke, the second spur gear is rotated around the idler gear and the first gear member on the second output to thereby cause the second gear member on the second output and the second bevel gear to advance or regress relative to the first gear member on the cage and the first bevel gear on the first output to thereby alter the phase relationship between the outputs.
In the second embodiment of the invention, the bevel gears and pinion gears, together with the intermediate shaft, take up a reaction caused by torque in the system rather than having the reaction applied against the moveable yoke.
Further, the bevel gears also distribute the torque equally between the output shafts. Furtherstill, these arrangements cause both shafts to be counter-rotated equally during the phase change operation.
In a third embodiment of the invention, the drive means comprises a cage coupled to the input which carries at least one planet shaft, the planet shaft carrying a first planet gear which meshes with the first gear fixed to the first output, the planet shaft also carrying a second planet gear which meshes with the first gear mounted on the second output;
a first orbit gear arranged for rotation relative to the outputs and meshing with the first planet gear and a second orbit gear arranged for rotation relative to the outputs and engaging the second planet gear, one of the first or second orbit gears being fixed and the other of the first or second orbit gears being moveable relative to the said one of the orbit gears;
wherein the phase adjusting means comprises the moveable orbit gear which, upon rotation relative to the fixed orbit gear, causes the first gear fixed to the first output to advance or regress relative to the first gear fixed to the second output to in turn cause the phase relationship between the outputs to change; and
wherein the actuating means comprises a handle on the moveable orbit gear for moving the moveable orbit gear relative to the fixed orbit gear.
In a fourth embodiment of the invention, a first of the output shafts includes a first cage and a second of the output shafts includes a concentric second cage:
the plurality of first gear members comprising a plurality of first bevel gears and a plurality of second bevel gears;
the first plurality of bevel gears being mounted on the first cage, and the second plurality of bevel gears being mounted on the second cage;
the input having a first bevel gear for engaging the first plurality of bevel gears on the first cage for driving the first cage to in turn rotate the first output shaft;
the input having a second bevel gear for engaging the second plurality of bevel gears on the second cage for rotating the second cage to in turn rotate the second output shaft;
the drive means comprising the first and second bevel gears of the input and the first and second plurality of bevel gears mounted on the first cage and the second cage.
In the fourth embodiment of the invention, the phase adjusting means comprises at least one control rod having a bevel gear thereon for engaging the first plurality of bevel gears or the second plurality of bevel gears so that upon rotation of the control rod, the bevel gear on the control rod is rotated to causes the-first plurality of bevel gears to advance or regress relative to the second plurality of bevel gears to thereby change the phase relationship between the first and second output shafts.
Preferably the means for actuating the phase adjusting means comprises a bevel gear mounted on the control rod and a motor for driving the bevel gear on the control rod to in turn rotate the control rod.
Preferably first and second control rods are included each carrying first and second bevel gears for engaging respectively the first plurality of bevel gears on the inner cage and the second plurality of bevel gears on the outer cage and preferably first and second motors and first and second bevel gear arrangements are arranged for rotating the first and second control rods to cause the first plurality of bevel gears on the inner cage to advance or regress relative to the second plurality of bevel gears on the outer cage to thereby change the phase relationship between the first and second output shafts.
The invention in a further aspect may be said to reside in a phase control mechanism, including:
an input for supplying input rotary power;
a plurality of outputs, each for providing output rotary power;
a plurality of first gear members each coupled to a corresponding output of the plurality of outputs;
drive means for transmitting rotary power from the inputs to the outputs so that when the input is driven, power is supplied to the outputs for driving the outputs;
a transfer gear for rotation or operation independently of the input, the transfer gear being meshingly coupled to the first gear members for allowing rotary motion to be transferred between the first gear members; and
phase adjusting means for causing the first gear members to advance or regress relative to one another to change the phase relationship between the outputs.
In some embodiments of the invention, the transfer gear may form part of the drive means and be one of the gears in the drive means for transmitting rotary power from the input to the outputs. In other embodiments, the transfer gear may be separate from the drive means and not directly be involved in transmitting drive from the input to the outputs.
Preferably the transfer gear is meshingly coupled with the first gear members by being enmeshed with ancillary gears fixedly attached to the first gear members.
Preferably the transfer gear is mounted on the input.
Preferred embodiments of the invention will be described, by way of example, with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of a phase control mechanism according to a first embodiment of the invention;
FIG. 2 is a view of a phase control mechanism according to a second embodiment of the invention;
FIG. 3 is a view of a phase control mechanism according to a third embodiment of the invention; and
FIG. 4 is a view of a phase control mechanism according to a fourth embodiment of the invention;
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, an input shaft 1 carries an integral first output shaft 1a which is provided with a concentric second output shaft 2 which are both supported in a suitable casing (such as casing 7 which is only partly shown in FIG. 1). The input shaft 1 and output shaft 2 can rotate freely relative to one another and thus the output shafts 1a and 2 rotate freely relative to one another.
The output shaft 1a is provided with a first gear 3 which may be integral with the output shaft 1a or mounted on the shaft 1a for rotation with the shaft 1a. The output shaft 2 is also provided with a first gear 4 which may be integral with the output shaft 2 or fixed to the output shaft 2 for rotation with the output shaft 2. The casing 7 supports a fixed lay shaft 6 upon which is rotatably mounted a fixed spur cluster 8. The fixed spur cluster 8 has a first set of teeth 8a which mesh with teeth on the gear 3 and a second set of teeth 8b which mesh with a transfer gear 5 which is mounted on the shafts 1a and 2 for rotation relative to the shafts 1a and 2.
A yoke 10 is rotatably mounted on the shafts 1a and 2 for pivoting movement about the shafts 1a and 2. The yoke 10 supports a lay shaft 11 upon which is mounted a spur cluster 9. The cluster 9 has a first set of teeth 9a which engage teeth on the gear 4 and a second set of teeth 9b which engage the transfer gear 5.
A predetermined ratio exists between the teeth 9a and 9b, the purpose of which will be described in more detail hereinafter.
Drive is transmitted from the input shaft 1 to rotate the shaft 1a by virtue of the integral nature of shafts 1 and 1a. Rotation of shaft 1a rotates the gear 3. Rotation of the gear 3 drives the spur cluster 8 which in turn rotates the transfer gear 5. The transfer gear 5 therefore rotates the spur cluster 9 which in turn rotates the gear 4 and the output shaft 2. Thus, drive is transmitted from the input shaft 1 to the output shaft 2. If the yoke 10 is held in one position and the input shaft 1 rotated, drive is therefore transmitted to the output shafts 1a and 2 as described above so that the output shaft 1a and output shaft 2 rotate in unison.
To alter the phase relationship between the output shaft 1a and output shaft 2, the yoke 10 is pivoted about the shafts 1a and 2. Thus, if the yoke 10 is now rotated through some arc, the spur gear 9 and lay shaft 11 are moved with the yoke 10 about the shafts 1a and 2 and transfer gear 5 and gear 4. Movement of the spur gear 9 against the transfer gear 5 will cause the gear 4 to advance or regress its rotation in relation to the gear 3. This will therefore alter the phase relationship between the gear 3 and the gear 4 and therefore between the output shaft 1a and the output shaft 2. This action occurs both with the shafts rotating or stationary. Thus, in order to change the phase relationship between the output shaft 1a and output shaft 2, it is not necessary to stop a machine to which the mechanism is connected and the phase relationship between the shafts can be adjusted or changed simply by pivoting the yoke 10 about the shafts 1 and 2. The yoke 10 may be manually pivoted or depending on the environment in which the mechanism is used, pivoted or fully rotated by a suitable actuating mechanism (not shown).
The transfer gear 5 forms a transfer gear which, as explained above, meshes with the gears 8 and 9 which in turn mesh with the first gears 3 and 4 attached to the output shafts 1a and 2. The transfer gear is mounted on the input but is able to rotate or otherwise operate independently of the input and allows rotary motion to be transferred between the gears 3 and 4.
In the embodiment of FIG. 1, the torque of the system will cause a reaction in the moveable yoke 10 which, in some environments, may make it difficult or uncomfortable to move the yoke 10.
FIG. 2 shows a second embodiment of the invention in which this problem is overcome. In FIG. 2, similar reference numerals indicate similar parts to those described with reference to FIG. 1.
In this embodiment of the invention the input shaft 1 carries a pinion cage 15. The pinion cage 15 carries the first gear 3 which meshes with the teeth 8a of fixed spur 8. The cage 15 carries a pair of shafts 15a upon which right angled pinion gears 14 are mounted.
Gear 4 which is coupled to second output shaft 2 carries a bevelled gear 12 which meshes with the pinion gears 15a. First output shaft 1a is arranged concentrically in the output shaft 2 and carries a pinion gear 13 which also meshes with the gears 15. The shaft 2 is hollow to accommodate the intermediate shaft 1a. The shaft 1a has an extension 1b which is accommodated rotatably within the input shaft 1 so the shafts 1, 1a and 2 can rotate relative to one another.
As in the earlier embodiments, the yoke 10 carries the moveable cluster 9 which has teeth 9a in intermeshing engagement with the transfer gear 5 which in turn meshes with teeth 8b of fixed cluster 8. The moveable cluster 9 also meshes with gear 4 as in the previous embodiment.
In the embodiment of FIG. 2, the yoke 10 is designed so that it sits over the cage 15 so that the yoke 10 can be pivoted on the shafts 1 and 2 relative to the shafts 1a and 2 and cage 15.
When the input shaft 1 is rotated, cage 15 is also rotated to cause the pinion gears 14 to rotate the gears 12 and 13 so that the output shaft 2 is rotated. The phase relationship between the output shaft 1a and output shaft 2 is adjusted by simply pivoting or fully rotating the yoke 10 to cause the spur gear 9 to rotate about gears 4 and 5 to cause the gear 4 and therefore the bevel gear 12 to advance or regress relative to the gear 3 carried by cage 15 and therefore the bevel gear 13. Thus, the phase relationship between the output shaft 1a and output shaft 2 can again be adjusted by rotating the yoke 10.
The amount of phase change upon a predetermined amount of pivoting of the yoke 10 is set by the gear ratio between the teeth 9a and 9b on the cluster 9. Thus, the ratio between the teeth 9a and 9b can be set to provide a large amount of phase shift between the shafts 1 and 2 upon a predetermined amount of pivoting of the yoke 10 or a small amount of phase shift with the same amount of rotation of the yoke 10.
The arrangement described with reference to FIG. 2 reduces the reaction back to the moveable yoke 10 thereby making the moveable yoke 10 more easy to move particularly if manual adjustment of the yoke 10 is desired.
The transfer gear 5 in this embodiment also forms a transfer gear which operates in a similar manner to the transfer gear 5 described with reference to FIG. 1.
A third embodiment of the invention is shown in FIG. 3. Once again, like reference numerals indicate like parts to those described with reference to FIGS. 1 and 2.
In this embodiment of the invention, the input shaft 1 carries a moveable circular cage 1c. Arranged in cage ic are planet shafts 1d upon which two sets of planet gears 18 and 18' are arranged. One set of planet gears 18 mesh with first gear 3 connected to first output shaft 1a and the other set 18' meshes with gear 4 coupled to second output shaft 2. A fixed orbit gear 16 meshes with the planet gears 18' and a moveable orbit gear 17 meshes with the planet gears 18. The moveable orbit gear 17 can have a handle 19 to facilitate its rotation relative to gear 16.
When the input shaft 1 is rotated, the cage 1c is also rotated to thereby rotate the planet gears 18 and 18'. This causes the gears 3 and 4 to rotate in unison. If the moveable orbit gear 17 is rotated, it will alter the phase relationship between the gears 3 and 4 and therefore between the output 1a and output 2.
In FIG. 3, the orbit gears 16 and 17 form transfer gears which perform the same function as the gears 5 described with reference to FIGS. 1 and 2. In this embodiment, as explained above, the gear 17 is moveable relative to the gear 16.
FIG. 4 shows a further embodiment of the invention which is adapted for use in outboard motors for controlling the pitch of a propeller.
In this embodiment, the phase control mechanism has an input shaft 50 which carries a first bevel gear 52 and a second bevel gear 54 which are arranged in back to back relationship as seen in FIG. 4. The first bevel gear 52 meshes with a plurality of bevel gears 56 which are arranged on axles 58 coupled to an inner cage 60. The inner cage 60 forms part of an output shaft 61 and the output shaft 61 also includes an integral output shaft portion 62.
The second bevel gear 54 meshes with a plurality of bevel gears 64 which are mounted on axles 66 coupled to an outer cage 68. The outer cage 68 has a front cover plate 70 and forms part of a second concentric output shaft 71 which also includes an integral second output shaft portion 72. The cover plate 70 is bolted to a flange 72 of the cage 68 by bolts or screws 74.
As can be seen in FIG. 4, the first output shaft 62 is concentric with the shaft 72 and arranged within the shaft 72. The shaft 72 is obviously hollow to accommodate the shaft 62.
The input shaft 50 is hollow and a first control rod 80 is arranged within the input shaft 50 for rotation relative to shaft 50 and passes through the bevel gears 54 and 52. A bevel gear 82 is fixed to the shaft 80 and meshes with the bevel gears 56 which are coupled to the inner cage 60. The shaft 62 has a recess 84 for accommodating the end of the control rod 80. The control rod 80 is not coupled in the recess 84 so that the control rod 80 can rotate relative to the shaft 62.
A second control rod 86 is provided with a bore 88 and is arranged on the input shaft 50 and controller rod 80 as shown in FIG. 4 for location relative to the shaft 50 and rod 80. The second control rod 86 has a bevel gear 90 which meshes with the bevel gears 64 coupled to the outer cage 68.
The control rod 80 is provided with a bevel gear 92 and the control rod 86 is provided with a bevel gear 94. The bevel gear 92 engages with a bevel gear 96 which is coupled to a drive rod 98 which in turn can be driven by a motor 100. The bevel gear 94 engages with a bevel gear 102 which is mounted on a drive rod 104 which in turn can be rotated by a motor 102.
In order to provide output drive to the shafts 62 and 72, the input shaft 50 is driven by a power supply (not shown) such as the outboard motor (not shown) with which the phase control mechanism shown in FIG. 4 can be used. Rotation of the input shaft 50 will rotate the bevel gears 52 and 54 which in turn will drive the bevel gears 56 and 66 so that the inner cage 60 and outer cage 68 are rotated about the longitudinal axis of the input shaft 50 to in turn rotate the output shafts 72 and 62 to provide output power.
In order to adjust the phase of the shaft 62 with respect to the shaft 72 to, for example, alter the pitch of a propeller driven by the outboard motor, (not shown) either the control rod 80 or control rod 86 is rotated or, indeed, both control rods 80 and 86 can be rotated. Rotation of the control rod 80 will rotate the bevel gear 82 which will cause the bevel gears 56 to advance or regress relative to the bevel gears 64 to in turn cause the inner cage 60 to rotate relative to the outer cage 68 to thereby change the phase relationship between the shafts 72 and 62. Similarly, if the second control rod 86 is rotated, the bevel gear 90 will be rotated to cause the bevel gears 64 to advance or regress relative to the bevel gears 56 to also cause the cage 68 to rotate relative to the cage 60 to thereby change the phase relationship between the shafts 62 and 72. Thus, the phase relationship between the shafts 62 and 72 can be altered by rotation of the control rod 80, or rotation of the control rod 86 or rotation of both control rods 86 and 80.
The control rods 80 and 86 are preferably controlled by motors 100 and 102 which are preferably electric motors which can be actuated by an electric supply (not shown). Actuation of the motors 100 and 102 will rotate drive shafts 98 and 104 to in turn rotate bevel gears 96 and 102 so that the bevel gears 92 and 94 are driven to rotate the control rod 80 or control rod 86 about their respective longitudinal axes.
Thus, in the case of an outboard motor, the motors 102 and 100 can be actuated to selectively shift the phase of the rods 62 and 72 relative to one another to place a propeller (not shown) at a predetermined pitch suitable for take-off so that the outboard motor need not be highly revved in order to propel the boat from a stationary position. As the boat picks up speed, the pitch of the propeller can be altered accordingly by adjustment of the control rods 80 or 86 under the influence of motors 100 and 102 to set the pitch of the propellers for continued propulsion as the boat continues to move.
In FIG. 4, the bevel gears 52 and 54, which are effectively integral with one another being provided on the input shaft 50, form transfer gears which operate in the same manner as the gears 5 described with reference to FIGS. 1 and 2.
The phase control mechanism of FIG. 4 may be positioned beneath water level so it is water cooled and appropriate seals may be included to ensure that the mechanism is water-tight. A bearing 106 may be disposed between the control rod 86 and the cage 68 for supporting relative rotation of the cage 68 with respect to the control rod 86.
In the preferred embodiments of the invention described above, the phase relationship between two output shafts is adjusted. It would also be possible to alter the phase relationship between more than two output shafts by adding additional output shafts concentric with the output shafts 1a and 2 and duplicating the mechanism described above so that there would be a series of yokes 10 or moveable orbit gears 17 which can be adjusted to alter the phase relationship between three or more shafts.
Since modifications within the spirit and scope of the invention may readily be effected by persons skilled within the art, it is to be understood that this invention is not limited to the particular embodiment described by way of example hereinabove. | A phase control mechanism controls phase relationship between two shafts. The phase control mechanism may be used to control various mechanical devices such as the pitch of propellers of aircraft and boats, the pitch of power producing windmills, opening and closing lathe and drill chucks and controlling the eccentricity of some forms of continuously variable transmissions when the mechanisms are not only stationary but also in normal operational motion. The phase control mechanism includes first gears 3,4; 56,64 coupled to the output shafts which are to be phase controlled. A transfer gear 5; 16,17; 52,54 is provided for rotation or operation independent of the input and is coupled to the first gears 3,4; 56,64 to allow rotary motion to be transferred between the first gear members and a phase adjuster 10; 80 causes the first gears 3,4; 56,64 to advance or regress relative to one another to change the phase relationship between the outputs. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to the remote connection of subsea flowlines and, in particular, to method and apparatus for connecting subsea pipelines to a submerged structure without the use of divers. More particularly, the invention concerns attaching subsea pipelines to subsea manifolds employing a connecting tool which is capable of aligning, clamping, testing and maintaining the connections between the pipelines and the manifold.
SUMMARY OF THE INVENTION
The present invention provides improved method and apparatus for connecting a spool piece hub, connected to the manifold of a subsea structure or template, to a pipeline hub. In the method a remotely operated pipeline connecting tool is lowered from a surface vessel to the template and properly positioned over the pipeline and manifold hubs. The connector tool is latched to the spool piece and the spool piece hub and pipeline hub are drawn together by hydraulic cylinders attached to sliding frames on the connecting tool. The hubs are then clamped together and pressure tested.
To retrieve a spool piece for replacement the connecting tool is lowered and latched onto the spool piece which is disconnected by unclamping the spool piece hubs from the manifold and pipeline hubs. The sliding frames on the connecting tool spread the manifold and pipeline hubs and the connecting tool is locked to the spool piece which is lifted from between the hubs and retrieved. All connecting tool operations except the alignments are surface controlled, hydraulic power fluid being supplied from a surface vessel.
Prior to lowering the connecting tool a section of the pipeline containing the pipeline hub and a trunnion assembly attached thereto is lowered vertically to adjacent the spool piece hub. As the pipeline hub and trunnion assembly are lowered additional sections of pipe are connected to the initial pipeline section attached to the trunnion assembly. Lowering the continues until the trunnion assembly latches to the template. Additional sections of pipe are laid out and during the laying operations the pipeline pivots 90° to the horizontal at the trunnion assembly which places the pipeline hub in final position for connection to the spool piece hub.
The apparatus for carrying out the method of the invention includes a spool piece having one spool piece hub adjacent said pipeline hub for connection thereto and the other hub thereof connected to a manifold hub which connects to a template; clamp means arranged on the spool piece hub for clamping the spool piece hub and pipeline hub together; and a remotely operated connecting tool having guidance frame means engageable with the manifold hub, landing frame means engageable with the pipeline hub, means connecting the guidance frame means and the landing frame means for moving the spool piece hub into connection with the pipeline hub; means for engaging the clamp means for operating the clamp means to clamp the spool piece hub and pipeline hub together and means for releasably locking the connector tool to the spool piece. In addition, conduit means are provided on the clamp means for supplying fluid to the connected hubs to test the connection and means are provided on the connecting tool for connecting the conduit means to a source of fluid. The spool piece may include a hydraulically operable valve, the operation thereof being controlled from the template through connections in the manifold and spool piece hubs.
Further, the apparatus includes two guide posts connected to guidelines; a pipeline section having a pipeline hub; a trunnion assembly attached to the pipeline section and containing guide funnels and a latch for latching onto the template.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are schematic views of a pipeline hub being positioned on a subsea template in alignment with a spool piece hub in accordance with the method of the invention;
FIG. 3 is a schematic view of a remote pipeline connecting tool positioned on the pipeline and manifold hub assemblies for connecting the spool piece hub to the pipeline hub;
FIG. 4 is a schematic view of the spool piece hub clamped to the pipeline hub;
FIG. 5 is a schematic view illustrating recovery of the connecting tool;
FIG. 6 is a side view which illustrates the apparatus for clamping the spool piece hub to the pipeline and manifold hubs;
FIG. 7 is a view taken along lines 7--7 of FIG. 6;
FIG. 8 is a view illustrating details of the connecting tool;
FIG. 9 is a view taken along lines 9--9 of FIG. 8;
FIG. 10 is a view taken along lines 10--10 of FIG. 8;
FIG. 11 is a fragmentary view illustrating one of the wobble plate assemblies positioned adjacent the spool piece hub;
FIG. 12 is a top view of the wobble plate assembly shown in FIG. 11;
FIG. 13 is a view taken along lines 13--13 of FIG. 12;
FIG. 14 is a view taken along lines 14--14 of FIG. 11; and
FIGS. 15 and 16 are fragmentary views illustrating operation of the latch fingers.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIG. 1 there is shown a subsea template 10 to which is latched a trunnion assembly 11 by latches 13 having latch releasing arms 13A and to which is pivotally attached by pins 11A a pipeline 14 with a connection hub 15. Trunnion assembly 11 also includes a base member 12, guide funnels 12A and other suitable securing means as, for example, tapered pins extending from base member 12 into holes in template 10, not shown, to fix trunnion assembly 11 on template 10. An isolation valve 16 is located on pipeline 14 adjacent trunnion assembly 11 on which pipeline 14 and hub 15 pivot relative to base member 12. Pipeline 14, hub 15 and trunnion assembly 11 are lowered into position on template 10 by two guide posts 17 positioned on template 10 and guide cables 18 connected to the guide posts. Base member 12 is latched to template 10 by latch 13, as shown. A valve spool piece 19 contains a valve 20 and a hub 21 to which hub 15 is to be connected and a hub 22 which is connected to a hub 23 of a manifold hub assembly 24 connected to manifold piping 24. Valve 20 is a balanced stem fail-safe valve such as described and claimed in U.S. No. 3,933,338 by D. P. Herd et al. Hub assembly 24 is supported by and shear pinned to a post 27 supporting cone end support 26. Hubs 22 and 23 are clamped together by a clamp assembly 50 and hub 21 is provided with a clamp assembly 51 which is used to clamp it to hub 15. Each clamp assembly is the type clamp connector described and claimed in U.S. Pat. No. 3,843,168 by C. D. Morrill et al. In FIG. 2 pipeline hub assembly 11 is shown pivoted into horizontal and properly aligned with valve spool 19 for connection of hubs 15 and 21.
Referring to FIG. 3 a remote pipeline connecting tool 30 is lowered on drill pipe 31 from the water's surface guided by guide posts 17 and cables 18 and guide sleeves 17A on the connecting tool onto trunnion assembly 11 and manifold hub assembly 24. Connecting tool 30 includes a support frame 32 which provides structural support for the other components of the connecting tool. A valve operator 33 is supported on frame 32. A wobble plate assembly 34 includes vertical plate assemblies 35 and 36 slidably mounted on guide rods 37 and 38 which are secured to frame 32. A pair of piston-cylinder assemblies 39 connect plate 35 of wobble plate assembly 34 and a guidance frame 40. As shown, guidance frame 40 is positioned adjacent hub 23 of the manifold hub assembly 24. A landing frame 41, shown in landed position on trunnion assembly 11, is located adjacent hub 15. A pair of piston-cylinder assemblies 42 connect landing frame 41 and guidance frame 40. Guidance frame 40 is also slidably mounted on guide rods 37 and 38 while landing frame 41 is slidably mounted on guide rods 37. A pair of piston-cylinder assemblies 43 connect landing frame 41 and support frame 32 as shown. Connecting tool 30 in FIG. 3 is in position for moving hub 21 to hub 15.
In FIG. 4 hubs 15 and 21 are shown made up and clamped together by clamp assembly 51 and valve actuator 33 is in position to open or close isolation valve 16. Manifold piping 25 contains a loop, not shown, that acts as a spring to allow manifold hub movement without overstressing the piping.
In FIG. 5 connecting tool 30 is shown being retrieved to the surface following successful testing of the made up connection. FIG. 5 also illustrates lowering of connecting tool 30 into position on trunnion assembly 11 and the manifold hub assembly 24 for removal of spool piece 19.
Referring now to FIGS. 6 and 7 in which the details of spool piece 19 and clamp assemblies 50 and 51 on hubs 21 and 22 are illustrated. Clamp assemblies 50 and 51 each include a vertical plate 52 bolted to each hub 21 and 22 by bolts 53. A pair of horizontal plates 54 on each clamp assembly support a pair of guide sleeves 55 and clamp operating rods 56 which are provided with hex shaped wrench heads 57. Also supported on one of the horizontal plates 54 is the male half of test hydraulic connector 58 which is connected by a conduit 59 to a port, not shown, on each hub 21 and 22 between seals 60 and 61 (indicated on the contacting surface face of hub 21). Clamp halves 62 are shown threaded onto rods 56. The clamp assemblies are in closed position on hub 22 and in the open position on hub 21. A semicircular saddle sleeve 66 is fixed to the back of plate 52.
Plate 52 has an opening 63 at its upper end forming lug ears 64 which are shown engaged by latch fingers 65 (see FIG. 7).
Guidance frame 40, as seen in FIGS. 8 through 10, includes guide yoke 40A, the lower tapered, wedge-shaped portion of which aids in moving manifold hub assembly 24 into proper position with respect to spool piece 19. Each plate assembly 35 and 36 includes a plate 73 and a wobble plate 74, the latter being pulled against plate 73 by tie rods 75. Guidance frame 40 is attached to sleeves 70 which slide on guide rods 37 and 38. Plates 73 of wobble plate assembly 34 are attached to sleeves 71 which slide on guide rods 37 and 38. Landing frame 41 is attached to sleeves 72 which slide on upper guide rods 37. A plate 76 is movably mounted on a roller 77 which is attached to each wobble plate 74. Attached to the underside of each plate 76 are downwardly extending guide pins 78. Each plate 76 also has a pair of torque motors 79 attached to it.
In FIG. 11 it is seen that each motor 79 is attached to a wrench 80 which extends below plate 76 and is positioned to engage a hex head 57 of the clamp assemblies. Each wobble plate 74 sits on a semicircular shoulder 81 attached to plate 73 by bolts 82. The center portion 83 of the upper surface of each wobble plate 74 is formed as a curved surface having a center point 84 which is also the center point for the semicircular surface 91 on shoulder 81. A roller 85 is mounted on plate 73 and bears against curved surface 83. A pair of centering springs 86 surround pins 87 which are attached to the upper end of plate 74 and extend through spring retainer boxes 88 which are attached to plate 73 by bolts 89. Each of the two tie rods 75 extend through an enlarged opening 90 in plate 73. The limited movement afforded by the mountings of plates 74 and 76 permits adjustments in aligning guide sleeves 55 with guide pins 78 and hex heads 57 with wrenches 80. When the wobble plates are lowered into position on valve spool 19 surfaces 91A engage saddle sleeves 66. In that position of connecting tool 30 guide pins 78 are aligned in sleeves 55 and wrenches 80 engage wrench heads 57.
Referring to FIGS. 12 through 16, in which details of the latch assemblies are shown, latch pins 65 are mounted in openings 95 on a rod 96 which is mounted for rotation in each wobble plate 74. A piston-cylinder assembly 97 is pivotally connected at one end to wobble plate 74, as at 98, and at the other end to link arm 99 which is also attached to rod 96. When shoulder 81 engages saddle sleeve 66 (see FIG. 11) latch fingers 65 are in position within opening 63 to be extended and engage underneath ears 64. Once so extended, spring fingers 76 lock connecting tool 30 to spool piece 19.
In operation, after guide posts 17 and guidelines 18 are installed at a prepared location on template 10 trunnion assembly 11, with pipeline 14 and hub 15 attached, is lowered with guidelines 18 within the two guide funnels 12A of the trunnion assembly. As trunnion assembly 11 is lowered additional sections of pipe are joined to the original pipeline section. Addition of pipe sections continues until guide funnels 12A slide over guide posts 17. Lowering continues until latches 13 latch trunnion assembly 11 to template 10. An additional sections of pipeline are laid out pipeline section 14 is pivoted 90° from vertical to horizontal which places pipeline hub 15 in final position for connection to spool piece hub 21.
Connecting tool 30 is then lowered with guidelines 18 within guide sleeves 17A to guide posts 17 where initial alignment is achieved. As lowering continues guidance yoke 40A of guidance frame 40 engages manifold hub assembly 24 between hub 23 and cone-shaped support 26. The three points of alignment, the two guide posts and the manifold hub correctly position connecting tool 30 over pipeline hub 15 and spool piece hub 21. Lowering continues and the weight of connecting tool 30 is landed on trunnion assembly 11 by landing frame 41. The hydraulically powered landing frame 41 is retracted by piston-cylinders 43 and the entire connecting tool 30 drops from its landing point into position for pipeline connection. During the last downward movement wobble plate assembly 34 permits final alignment of guide pins 78 and sleeves 55. Latch fingers 65 are activated to lock connecting tool 30 and spool piece 19 together. Spool piece hub 21 and pipeline hub 15 are drawn together by hydraulic cylinder assemblies 42 attached to sliding guidance and landing frames 40 and 41, respectively, of connecting tool 30. Movement of manifold piping 25 toward pipeline hub 15 disconnects the manifold piping 25 from post 27 by shearing the pins connecting them. The female half of connector 58 on hydraulic connecting tool 30 is extended to connect with the male half of hydraulic connector 58 on clamp assembly 51, the seals between hubs 15 and 21 are then tested for pressure integrity. A suitable hydraulic connector 58 may be that disclosed and claimed in U.S. Pat. No. 3,918,485 by R. A. Weber et al. After a good pressure test and on command from the surface connecting tool 30 opens manual isolation valve 16 and releases latch fingers 65 from spool piece 19. The tool is retrieved to the surface, guidelines are retrieved and the connection is complete.
To retrieve a spool piece for replacement, connecting tool 30 is lowered and latched onto the installed spool piece 19. Spool piece 19 is disconnected from the manifold and pipeline hubs by operation of torque motors 79 to release clamp assemblies 50 and 51 and by operation of piston-cylinder assemblies 39 and 43 to move guidance frame 40 and landing frame 41 to spread the manifold and pipeline hubs. The wobble plate assembly 34 is centered and spool piece 19 is lifted from between the hubs and connecting tool 30 is retrieved.
In U.S. Pat. No. 3,775,986 entitled "Method and Apparatus of Making Remote Pipeline Connections" a "pull-in" method to align subsea pipelines is disclosed and claimed. The method of the present invention for connecting the pipeline hub to the spool piece hub may also be used with that "pull-in" method once the pipeline hub and spool piece hub are properly positioned and aligned.
Spool piece 19 may be, as described, a valve spool or it may be a pipe, control pod or any other maintainable component. Also, the method for connecting the pipelines may be conducted from a floating vessel or grounded platform. Further, instead of guidelines to guide the trunnion assembly and connecting tool into proper position other known guiding techniques, such as the acoustic positioning technique, may be used. Other changes and modifications may be made in the illustrative embodiments of the invention shown and/or described herein without departing from the scope of the invention as defined in the appended claims. | A subsea pipeline hub is connected to the hub of an adjacent spool piece connected to an in-place manifold of a subsea structure used in the production of oil and/or gas. The pipeline hub is positioned relative to the opposing spool hub and a remotely operated pipeline connecting tool is lowered from the water's surface to the subsea structure using guidelines and structural guidance for alignment of the pipeline hub with the spool piece hub. The spool piece hub is then drawn to the pipeline hub and the hubs are clamped together by operation of the connecting tool. The seal in the connection can be tested by means of the connecting tool. The spool piece may be retrieved and replaced by the connecting tool if maintenance is needed. Connecting tool operations are powered by hydraulic fluid and controlled from the surface. The pipeline hub may be lowered vertically and pivoted into its position adjacent the spool piece or may be pulled into that position. | 4 |
[0001] This application is a continuation-in-part of non-provisional application Ser. No. 09/788,201 filed Feb. 16, 2001, which claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Application Serial No. 60/183,396 filed Feb. 18, 2000.
TECHNICAL FIELD
[0002] The present invention is directed to the field of synthesizing epoxides of steroids.
BACKGROUND OF THE INVENTION
[0003] Steroid epoxides are an important class of oxysterols (oxygenated derivatives of cholesterol) involved in the regulation of cell proliferation and cholesterol homeostasis. They are versatile intermediates for steroid synthesis and useful probes for biochemical studies of enzymes. Steroid epoxides are also useful intermediates for the preparation of other oxysterols. For example, α- and β-epoxides of cholesterol are auto-oxidation products of cholesterol in vivo, and both are cytotoxic and mutagenic. The isomeric α- and β-epoxides are hydrolysed by cholesterol 5,6-epoxide hydrolase to cholestane-3β,5α,6β-triol which has potent hypocholesterolemic activity. On the other hand, both epoxides inhibit the cholesterol 7α-hydroxylase which catalyzes the rate-determining step of bile acid synthesis. As 5α,6α-epoxides are readily available via epoxidation of Δ 5 -unsaturated steroids with peracids, there have been extensive studies on the biological actions of those epoxides and their derivatives. In contrast, much less is known about the 5β,6β-epoxides and their derivatives because they are difficult to obtain in high selectivity. More importantly, the 5β,6β-epoxy functionality is found in a number of naturally occurring steroids of antitumor activities, e.g., jaborosalactone A, withaferin A, and withanolide D.
[0004] Common organic oxidants such as 3-chloroperoxybenzoic acid (mCPBA) generally give α-epoxides as the major products for epoxidation of 3β-substituted Δ 5 -steroids and show poor selectivities for epoxidation of 3α-substituted Δ 5 -steroids except epi-cholesterol. This is because peracid epoxidation follows a concerted pathway via spiro transition states (α-TS and β-TS (TS=transition state); see FIG. 1). The β-TS suffers from steric interactions between the peracid and the C(10) angular methyl group for epoxidation of 3β-substituted Δ 5 -steroids, while both the β-TS and the α-TS encounter similar steric hindrance for epoxidation of 3α-substituted Δ 5 -steroids. Dioxiranes are new-generation reagents for oxidation under mild and neutral conditions. Unfortunately, poor selectivities were reported in epoxidation of 3β-substituted Δ 5 -steroids by either isolated or in situ generated dioxiranes. While dioxiranes also epoxidize olefins through a spiro TS, their steric environment is different from that of peracids. To minimize steric interactions, dioxiranes prefer to approach the C(5)═C(6) double bond of Δ 5 -steroids from the less-substituted side, i.e., away from the C(10)-angular methyl group and the C-ring of steroids (FIG. 1). Therefore, it is the potential steric interactions between the α-substituents of dioxiranes and the 3α and 4β substituents of steroids that determine the facial selectivity of epoxidation.
[0005] Yang et al., in U.S. Pat. No. 5,763,623 and in J. Org. Chem., 1998, vol. 63 pages 8952-8956, disclose the epoxidation of unfunctionalized olefins using various ketones. These references do not teach or suggest the epoxidation of Δ 5 -unsaturated steroids.
[0006] Cicala, G., et al., J. Org. Chem., 1982, vol. 47, pages 2670-2673, disclose the epoxidation of a Δ 5 -unsaturated steroid that is not a 3α-substituted Δ 5 -unsaturated steroid, and in which the ketone catalyst is acetone.
[0007] Marples, B. A., et al. Tetrahedron Lett., 1991, vol. 32, pages 533-536, disclose the epoxidation reactions of four Δ 5 -unsaturated steroids that are not 3ax-substituted Δ 5 -unsaturated steroids, and using a variety of ketones. In these reactions either no epoxide was observed, or the β/α-epoxide ratio was about 1:1.
[0008] Bovicelli, P., et al., J. Org. Chem., 1992, vol. 57, pages 2182-2184, disclose the epoxidation of a Δ 5 -unsaturated steroid that is not a 3α-substituted Δ 5 -unsaturated steroid, and using dimethyldioxirane. The β/α-epoxide ratio was about 3:1.
[0009] Boehlow, T. R., et al., Tetrahedron Lett., 1998, vol. 39, pages 1839-1842, disclose the epoxidation of a Δ 5 -unsaturated steroid that is not a 3α-substituted Δ 5 -unsaturated steroid, and using a variety of ketone catalysts.
[0010] Shi, Y., in PCT Publication No. WO 01/12616 A1, Feb. 22, 2001, discloses an epoxidation method combining an olefin substrate, a ketone catalyst, a nitrile compound, and hydrogen peroxide.
[0011] Shi, Y., in PCT Publication No. WO 98/15544, Apr. 16, 1998, discloses the use of a chiral ketal and an oxidizing agent with an olefin to generate an epoxide with high enantioselectricity.
SUMMARY OF THE INVENTION
[0012] In accordance with the invention, a method is provided for producing mostly 5β,6β-epoxides of Δ 5 -unsaturated steroids using certain ketones as the catalyst along with an oxidizing agent, or by using certain dioxiranes. In another aspect of the invention, a method is provided for producing mostly 5β,6β-epoxides of steroids from Δ 5 -unsaturated steroids having a substituent at the 3α-position by an epoxidation reaction using a ketone along with an oxidizing agent under conditions effective to generate epoxides, or using a dioxirane under conditions effective to generate epoxides.
[0013] A whole range of Δ 5 -unsaturated steroids, bearing different functional groups such as hydroxy, carbonyl, acetyl or ketal group, as well as different side chains, are converted to the corresponding synthetically and biologically interesting 5β,6β-epoxides with excellent β-selectivities and high yields.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a diagrammatic representation of the general epoxidation reaction between Δ 5 -unsaturated steroids and mCPBA or dioxirane;
[0015] [0015]FIG. 2 is a listing of chemical structures corresponding to ketones 1-4 and steroids 5-20;
[0016] [0016]FIG. 3 is a diagrammatic representation of the epoxidation reaction of the present invention; and
[0017] FIGS. 4 - 70 are 1 H NMR spectra of 5,β,6β-epoxides of steroids and 5α,6α-epoxides of steroids including those epoxides of steroids synthesized as products by the method of the present invention and purified epoxides of steroids used as comparative control standards (referred to as “authentic samples”).
DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention provides highly β-selective epoxidation of Δ 5 -unsaturated steroids catalyzed by ketones or mediated by dioxiranes. More specifically, the present invention demonstrates that high β-selectivity can be achieved by increasing the steric size of either the α-substituents of dioxiranes or the 3α substituents of Δ 5 -steroids. In some embodiments of the invention, the epoxidation reaction can provide said epoxides in at least about 5:1β/α-epoxide ratio.
[0019] In one aspect of the invention, a method of producing mostly 5β,6β-epoxides of steroids from Δ 5 -unsaturated steroids comprises an epoxidation reaction using a ketone and an oxidizing agent under conditions effective to generate epoxides, wherein the ketone is selected from compounds of generic formula I,
[0020] in which R 1 or R 4 in formula (I) is selected from alkyl, halogenated alkyl, aryl, OR (where R=H, alkyl or aryl), OCOR (where R=H, alkyl or aryl), OCOOR (where R=alkyl or aryl), OCOOCH 2 R (where R=aryl), OCONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), OSiR 1 R 2 R 3 (where R 1 , R 2 or R 3 =alkyl or aryl), and halogen;
[0021] R 2 or R 3 in formula (I) is selected from H, alkyl, halogenated alkyl, aryl, OR (where R=H, alkyl or aryl), OCOR (where R=H, alkyl or aryl), OCOOR (where R=alkyl or aryl), OCOOCH 2 R (where R=aryl), OCONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), OSiR 1 R 2 R 3 (where R 1 , R 2 or R 3 =alkyl or aryl), and halogen;
[0022] R 5 , R 6 , R 7 or R 8 in formula (I) is selected from H, alkyl, halogenated alkyl, aryl, COOR (where R=H, alkyl or aryl), and CONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl);
[0023] R 9 or R 10 in formula (I) is selected from alkyl, halogenated alkyl, and aryl; and
[0024] A in formula (I) is selected from halogen, OTf, BF 4 , OAc, NO 3 , BPh 4 , PF 6 , and SbF 6 .
[0025] In another aspect of the invention, a method of producing mostly 5β,6β-epoxides of steroids from Δ 5 -unsaturated steroids having a substituent at the 3α-position comprises an epoxidation reaction using a ketone and an oxidizing agent under conditions effective to generate epoxides. The substituent at the 3α-position can be selected from OR (where R=H, alkyl or arly), O(CH 2 ) n OR (where n=1, 2 or 3, R=H, alkyl or aryl), O(CH 2 ) m SO n R (where n=1, 2 or 3; n=0, 1 or 2; R=H, alkyl or aryl), OSiR 1 R 2 R 3 (where R 1 , R 2 or R 3 =alkyl or aryl), OSO n R where n=0, 1 or 2; R=H, alkyl or aryl), OCO n R (where n=1 or 2; R=H, alkyl or aryl), OCONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), OPO n R (where where n=2 or 3; R=alkyl or arly), NR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), NR 1 CO n R 2 (where n=1 or 2; R 1 or R 2 =H, alkyl or aryl), NR 1 CONR 2 R 3 (where R 1 , R 2 or R 3 =H, alkyl or aryl), NR 1 SO n R 2 (where n=1 or 2; R 1 =H, alkyl or aryl, R 2 =alkyl or aryl), NPhth (Phth=phthaloyl group), + NR 1 R 2 R 3 (where R 1 , R 2 , or R 3 =H, alkyl or aryl), SiR 1 R 2 R 3 (where R 1 , R 2 , or R 3 =H, alkyl or aryl), SO n R (where n=0, 1 or 2; R=H, alkyl or aryl), SCO n R (where n=1 or 2; R=H, alkyl or aryl), halogen, CN, NO 2 , alkyl, aryl, COOR (where R=H, alkyl or aryl), and CONR 1 R 2 (where R 1 or R 2 =H, alkyl or arly).
[0026] Further in accordance with this aspect of the invention, the Δ 5 -unsaturated steroid having a substituent at the 3α-position can be selected from the group consisting of Δ 5 -unsaturated steroids having a ketal derivative of ketone group or a thioketal derivative of ketone group at the 3-position.
[0027] Further in accordance with this aspect of the invention, the ketone used in the epoxidation reaction can be selected from the group consisting of compounds of generic formula II, III, IV, and V wherein
[0028] R 1 , R 2 , R 3 , or R 4 in formula (II) is selected from H, alkyl, halogenated alkyl, aryl, OR (where R=H, alkyl or aryl), OCOR (where R=H, alkyl or aryl), OCOOR (where R=alkyl or aryl), OCONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), OSiR 1 R 2 R 3 (where R 1 , R 2 or R 3 =alkyl or aryl), and halogen;
[0029] R 5 , R 6 , R 7 , R 8 , R 9 or R 10 in formula (II) is selected from H, alkyl, halogenated alkyl, aryl, COOR (where R=H, alkyl or aryl), and CONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl);
[0030] A in formula (iI) is selected from halogen, OTf, BF 4 , OAc, NO 3 , BPh 4 , PF 6 , and SbF 6 ;
[0031] X in formula (III) is selected from (CR 1 R 2 ) n (where n=1, 2, 3, 4, or 5; R 1 or R 2 =H, alkyl or aryl), O, S, SO, SO 2 , and NR (where R=H, alkyl or aryl);
[0032] R 11 , R 12 , R 13 , or R 14 in formula (III) is selected from H, alkyl, halogenated alkyl, aryl, OR (where R=H, alkyl or aryl), OCOR (where R=H, alkyl or aryl), OCOOR (where R=alkyl or aryl), OCONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), OSiR 1 R 2 R 3 (where R 1 , R 2 or R 3 =alkyl or aryl), and halogen;
[0033] R 15 , R 16 , R 17 , or R 18 in formula (III) is selected from H, alkyl, halogenated alkyl, aryl, COOR (where R=H, alkyl or aryl), and CONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl);
[0034] R 19 or R 20 in formula (IV) is selected from alkyl, halogenated alkyl, aryl, CR 1 R 2 OCOR 3 (where R 1 , R 2 or R 3 =H, alkyl or aryl), CR 1 R 2 OCOOR 3 (where R 1 or R 2 =H, alkyl or aryl; R 3 =alkyl or aryl), CR 1 R 2 NR 3 COOR 4 (where R 1 , R 2 or R 3 =H, alkyl or aryl, R 4 =alkyl or aryl), CR 1 R 2 NR 3 COR 4 (where R 1 , R 2 , R 3 or R 4 =H, alkyl or aryl), and CR 1 R 2 NR 3 SO 2 R 4 (where R 1 , R 2 or R 3 =H, alkyl or aryl; R 4 =alkyl or aryl); and
[0035] Y in formula (V) is selected from H, alkyl, halogenated alkyl, aryl, NO 2 , CN, F, Cl, Br, I, COOR (where R=H or alkyl), OR (where R=H, alkyl or aryl), OSO 2 R (where R=H, alkyl or aryl), OSOR (where R=H, alkyl or aryl), OSR (where R=H, alkyl or aryl), S0 2 R (where R=H, alkyl or aryl), SO 3 R (where R=H, alkyl or aryl), SOON R 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), NR 1 SOOR 2 (where R 1 =H, alkyl or aryl; R 2 =alkyl or aryl), NR 1 SOR 2 (where R 1 =H, alkyl or aryl; R 2 =alkyl or aryl), CR 1 R 2 OR 3 (where R 1 , R 2 or R 3 =H, alkyl or aryl), CR 1 (OR 2 ) 2 (where R 1 =H or alkyl; R 2 =alkyl), CF 3 , CF 2 CF 3 , OTf, OTs, OCOR (where R=H, alkyl or aryl), and OSiR 1 R 2 R 3 (where R 1 , R 2 or R 3 =alkyl or aryl).
[0036] In yet another aspect of the invention, a method of producing mostly 5,6β-epoxides of steroids from Δ 5 -unsaturated steroids comprises an epoxidation reaction using a dioxirane under conditions effective to generate epoxides, wherein said dioxirane is selected from compounds of generic formula VI,
[0037] R 1 or R 4 in formula (VI) is selected from alkyl, halogenated alkyl, aryl, OR (where R=H, alkyl or aryl), OCOR (where R=H, alkyl or aryl), OCOOR (where R=alkyl or aryl), OCOOCH 2 R (where R=aryl), OCONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), OSiR 1 R 2 R 3 (where R 1 , R 2 or R 3 =alkyl or aryl), and halogen;
[0038] R 2 or R 3 in formula (VI) is selected from H, alkyl, halogenated alkyl, aryl, OR (where R=H, alkyl or aryl), OCOR (where R=H, alkyl or aryl), OCOOR (where R=alkyl or aryl), OCOOCH 2 R (where R=aryl), OCONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), OSiR 1 R 2 R 3 (where R 1 , R 2 or R 3 =alkyl or aryl), and halogen;
[0039] R 5 , R 6 , R 7 or R 8 in formula (VI) is selected from H, alkyl, halogenated alkyl, aryl, COOR (where R=H, alkyl or aryl), and CONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl);
[0040] R 9 or R 10 in formula (VI) is selected from alkyl, halogenated alkyl, and aryl; and
[0041] A in formula (VI) is selected from halogen, OTf, BF 4 , OAc, NO 3 , BPh4, PF 6 , and SbF 6 .
[0042] The dioxirane can be generated in situ from a ketone and an oxidizing agent selected from potassium peroxomonosulfate, sodium hypochlorite, sodium perborate, hydrogen peroxide, and peracids, wherein said ketone is selected from compounds of generic formula I,
[0043] R 1 or R 4 in formula (I) is selected from alkyl, halogenated alkyl, aryl, OR (where R=H, alkyl or aryl), OCOR (where R=H, alkyl or aryl), OCOOR (where R=alkyl or aryl), OCOOCH 2 R (where R=aryl), OCONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), OSiR 1 R 2 R 3 (where R 1 , R 2 or R 3 =alkyl or aryl), and halogen;
[0044] R 2 or R 3 in formula (I) is selected from H, alkyl, halogenated alkyl, aryl, OR (where R=H, alkyl or aryl), OCOR (where R=H, alkyl or aryl), OCOOR (where R=alkyl or aryl), OCOOCH 2 R (where R=aryl), OCONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), OSiR 1 R 2 R 3 (where R 1 , R 2 or R 3 =alkyl or aryl), and halogen;
[0045] R 5 , R 6 , R 7 or R 8 in formula (I) is selected from H, alkyl, halogenated alkyl, aryl, COOR (where R=H, alkyl or aryl), and CONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl);
[0046] R 9 or R 10 in formula (I) is selected from alkyl, halogenated alkyl, and aryl; and
[0047] A in formula (I) is selected from halogen, OTf, BF 4 , OAc, NO 3 , BPh 4 , PF 6 , and SbF 6 .
[0048] In yet another aspect of the invention, a method of producing mostly 5β,6β-epoxides of steroids from Δ 5 -unsaturated steroids having a substituent at the 3α-position comprises an epoxidation reaction using a dioxirane under conditions effective to generate epoxides. In accordance with this aspect of the invention, the substituent at the 3α-position can be selected from OR (where R=H, alkyl or aryl), O(CH 2 ) n OR (where n=1, 2 or 3, R=H, alkyl or aryl), O(CH 2 ) m SO n R (where n=1, 2 or 3; n=0, 1 or 2; R=H, alkyl or aryl), OSiR 1 R 2 R 3 (where R 1 , R 2 or R 3 =alkyl or aryl), OSO n R (where n=0, 1 or 2; R=H, alkyl or aryl), OCO n R (where n=1 or 2; R=H, alkyl or aryl), OCONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), OPO n R (where where n=2 or 3; R=alkyl or aryl), NR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), NR 1 CO n R 2 (where n=1 or 2; R 1 or R 2 =H, alkyl or aryl), NR 1 CONR 2 R 3 (where R 1 , R 2 or R 3 =H, alkyl or aryl), NR 1 SO n R 2 (where n=1 or 2; R 1 =H, alkyl or aryl, R 2 =alkyl or aryl), NPhth (Phth=phthaloyl group), + NR 1 R 2 R 3 (where R 1 , R 2 , or R 3 =H, alkyl or aryl), SiR 1 R 2 R 3 (where R 1 , R 2 , or R 3 =H, alkyl or aryl), SO n R (where n=0, 1 or 2; R=H, alkyl or aryl), SCO n R (where n=1 or 2; R=H, alkyl or aryl), halogen, CN, NO 2 , alkyl, aryl, COOR (where R=H, alkyl or aryl), and CONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl).
[0049] Further in accordance with this aspect of the invention, the Δ 5 -unsaturated steroid having a substituent at the 3α-position can be selected from the group consisting of Δ 5 -unsaturated steroids having a ketal derivative of a ketone group or a thioketal derivative of a ketone group at the 3-position.
[0050] Further in accordance with this aspect of the invention, the dioxirane can be selected from the group consisting of compounds of generic formula VII, VIII, IX and X.
[0051] R 1 , R 2 , R 3 , or R 4 in formula (VII) is selected from H, alkyl, halogenated alkyl, aryl, OR (where R=H, alkyl or aryl), OCOR (where R=H, alkyl or aryl), OCOOR (where R=alkyl or aryl), OCCOOCH 2 R (where R=aryl), OCONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), OSiR 1 R 2 R 3 (where R 1 , R 2 or R 3 =alkyl or aryl), and halogen;
[0052] R 5 , R 6 , R 7 , R 8 , R 9 or R 10 , in formula (VII) is selected from H, alkyl, halogenated alkyl, aryl, COOR (where R=H, alkyl or aryl), and CONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl);
[0053] A in formula (VII) is selected from halogen, OTf, BF 4 , OAc, NO 3 , BPh 4 , PF 6 , and SbF 6 ;
[0054] X in formula (VIII) is selected from (CR 1 R 2 ) n , (where n=1, 2, 3, 4, or 5; R 1 or R 2 =H, alkyl or aryl), O, S, SO, SO 2 , and NR (where R=H, alkyl or aryl);
[0055] R 11 , R 12 , R 13 , or R 14 in formula (VIII) is selected from H, alkyl, halogenated alkyl, aryl, OR (where R=H, alkyl or aryl), OCOR (where R=H, alkyl or aryl), OCOOR (where R=alkyl or aryl), OCOOCH 2 R (where R=aryl), OCONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), OSiR 1 R 2 R 3 (where R 1 , R 2 or R 3 =alkyl or aryl), and halogen;
[0056] R 15 , R 16 , R 17 , or R 18 in formula (VIII) is selected from H, alkyl, halogenated alkyl, aryl, COOR (where R=H, alkyl or aryl), and CONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl);
[0057] R 19 or R 20 in formula (IX) is selected from alkyl, halogenated alkyl, aryl, CR 1 R 2 OCOR 3 (where R 1 , R 2 or R 3 =H, alkyl or aryl), CR 1 R 2 OCOOR 3 (where R 1 or R 2 =H, alkyl or aryl; R 3 =alkyl or aryl), CR 1 R 2 NR 3 COOR 4 (where R 1 , R 2 or R 3 =H, alkyl or aryl, R 4 =alkyl or aryl), CR 1 R 2 NR 3 COR 4 (where R 1 , R 2 , R 3 or R 4 =H, alkyl or aryl), CR 1 R 2 NR 3 SO 2 R 4 (where R 1 , R 2 or R 3 =H, alkyl or aryl; R 4 =alkyl or aryl); and
[0058] Y in formula (X) is selected from H, alkyl, halogenated alkyl, aryl, NO 2 , CN, F, Cl, Br, I, COOR (where R=H or alkyl), OR (where R=H, alkyl or aryl), OSO 2 R (where R=H, alkyl or aryl), OSOR (where R=H, alkyl or aryl), OSR (where R=H, alkyl or aryl), SO 2 R (where R=H, alkyl or aryl), SO 3 R (where R=H, alkyl or aryl), SOON R 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), NR 1 SOOR 2 (where R 1 =H, alkyl or aryl; R 2 =alkyl or aryl), NR 1 SOR 2 (where R 1 =H, alkyl or aryl; R 2 =alkyl or aryl), CR 1 R 2 OR 3 (where R 1, R 2 or R 3 =H, alkyl or aryl), CR 1 (OR 2 ) 2 (where R 1 =H or alkyl; R 2 =alkyl), CF 3 , CF 2 CF 3 , OTf, OTs, OCOR (where R=H, alkyl or aryl), and OSiR 1 R 2 R 3 (where R 1 , R 2 or R 3 =alkyl or aryl).
[0059] The dioxirane can be generated in situ from a ketone and an oxidizing agent selected from potassium peroxomonosulfate, sodium hypochlorite, sodium perborate, hydrogen peroxide, and peracids. In such embodiments of the invention, the ketone can be selected from the group consisting of compounds of generic formula II, III, IV, and V,
[0060] R 1 , R 2 , R 3 , or R 4 in formula (II) is selected from H, alkyl, halogenated alkyl, aryl, OR (where R=H, alkyl or aryl), OCOR (where R=H, alkyl or aryl), OCOOR (where R=alkyl or aryl), OCOOCH 2 R (where R=aryl), OCONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), OSiR 1 R 2 R 3 (where R 1 , R 2 or R 3 =alkyl or aryl), and halogen;
[0061] R 5 , R 6 , R 7 , R 8 , R 9 or R 10 in formula (II) is selected from H, alkyl, halogenated alkyl, aryl, COOR (where R=H, alkyl or aryl), and CONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl);
[0062] A in formula (II) is selected from halogen, OTf, BF 4 , OAc, NO 3 , BPh 4 , PF 6 , and SbF 6 ;
[0063] X in formula (III) is selected from (CR 1 R 2 ) n (where n=1, 2, 3, 4, or 5; R 1 or R 2 =H, alkyl or aryl), O, S, SO, SO 2 , and NR (where R=H, alkyl or aryl);
[0064] R 11 , R 12 , R 13 , or R 14 in formula (III) is selected from H, alkyl, halogenated alkyl, aryl, OR (where R=H, alkyl or aryl), OCOR (where R=H, alkyl or aryl), OCOOR (where R=alkyl or aryl), OCOOCH 2 R (where R=aryl), OCONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), OSiR 1 R 2 R 3 (where R 1 , R 2 or R 3 =alkyl or aryl), and halogen;
[0065] R 15 , R 16 , R 17 , or R 18 in formula (III) is selected from H, alkyl, halogenated alkyl, aryl, COOR (where R=H, alkyl or aryl), and CONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl);
[0066] R 19 or R 20 in formula (IV) is selected from alkyl, halogenated alkyl, aryl, CR 1 R 2 OCOR 3 (where R 1, R 2 or R 3 =H, alkyl or aryl), CR 1 R 2 OCOOR 3 (where R 1 or R 2 =H, alkyl or aryl; R 3 =alkyl or aryl), CR 1 R 2 NR 3 COOR 4 (where R 1 , R 2 or R 3 =H, alkyl or aryl, R 4 =alkyl or aryl), CR 1 R 2 NR 3 COR 4 (where R 1 , R 2 , R 3 or R 4 =H, alkyl or atyl), CR 1 R 2 NR 3 SO 2 R 4 (where R 1 , R 2 or R 3 =H, alkyl or aryl; R 4 =alkyl or aryl); and
[0067] Y in formula (V) is selected from H, alkyl, halogenated alkyl, aryl, NO 2 , CN, F, Cl, Br, I, COOR (where R=H or alkyl), OR (where R=H, alkyl or aryl), OSO 2 R (where R=H, alkyl or aryl), OSOR (where R=H, alkyl or aryl), OSR (where R=H, alkyl or aryl), SO 2 R (where R=H, alkyl or aryl), SO 3 R (where R=H, alkyl or aryl), SOON R 1 R 2 (where R 1 or R 2 =H, alkyl or aryl), NR 1 SOOR 2 (where R 1 =H, alkyl or aryl; R 2 =alkyl or aryl), NR 1 SOR 2 (where R 1 =H, alkyl or aryl; R 2 =alkyl or aryl), CR 1 R 2 OR 3 (where R 1 , R 2 or R 3 =H, alkyl or aryl), CR 1 (OR 2 ) 2 (where R 1 =H or alkyl; R 2 =alkyl), CF 3 , CF 2 CF 3 , OTf, OTs, OCOR (where R=H, alkyl or aryl), and OSiR 1 R 2 R 3 (where R 1 , R 2 or R 3 =alkyl or aryl).
[0068] Epoxidation reactions in accordance with the invention and using dioxiranes can be carried out in a solvent selected from acetonitrile, dimethoxymethane, acetone, dioxane, dimethoxyethane, tetrahydrofuran, dichloromethane, chloroform, benzene, toluene, diethylether, water and mixtures thereof.
[0069] In accordance with one embodiment of the invention herein, a method of producing mostly 5β,6β-epoxides of steroids comprises epoxidation reactions of Δ 5 -unsaturated steroids of generic formula XI catalyzed by ketones of generic formula XII, wherein
[0070] X 1 in formula (XI) is selected from H, OR (where R=H or alkyl), OCH 2 OCH 3 , OCOR (where R=alkyl or aryl), OSiR 1 ′R 2 ′R 3 ′ (where R 1 ′, R 2 ′ or R 3 ′=alkyl or aryl), halogen, CN, alkyl, aryl, and COOR (where R=H, alkyl or aryl);
[0071] R 1 in formula (XI) is selected from H, OR (where R=H or alkyl), OCOR (where R=alkyl or aryl), OCH 2 OCH 3 , halogen, CF 3 , and CF 2 CF 3 ;
[0072] R 2 and R 3 in formula (XI) are each selected from the group consisting of H, alkyl, aryl, halogen, OR (where R=H or alkyl), OCOR (where R=alkyl or aryl), OSiR 1 ′R 2 ′R 3 ′ (where R 1 ′, R 2 ′ or R 3 ′=alkyl or aryl), COR (where R=alkyl), COCH 2 OR (where R=H or alkyl), COCH 2 OCOR (where R=alkyl or aryl), COCH 2 F, COOR (where R=H or alkyl), C(OCH 2 CH 2 O)R (where R=alkyl), C(OCH 2 CH 2 )CH 2 OR (where R=H or alkyl), C(OCH 2 CH 2 O)CH 2 OCOR (where R=alkyl or aryl), and C(OCH 2 CH 2 O)CH 2 F; or, are selected from the group consisting of O, OCH 2 CH 2 O, and OCH 2 CH 2 CH 2 O;
[0073] R 4 in formula (XI) is selected from H, C 1 -C 4 alkyl, halogen, OR (where R=H or alkyl), OCOR (where R=alkyl or aryl), and OSiR 1 ′R 2 ′R 3 ′ (where R 1 ′, R 2 ′ or R 3 ′=alkyl or aryl);
[0074] R 5 in formula (XI) is selected from H, C 1 -C 4 alkyl, halogen, OR (where R=H or alkyl), OCOR (where R=alkyl or aryl), and OSiR 1 ′R 2 ′R 3 ′ (where R 1 ′, R 2 ′ or R 3 ′=alkyl or aryl);
[0075] R 6 in formula (XI) is selected from H, halogen, OR (where R=H or alkyl), and OCOR (where R=alkyl or aryl);
[0076] R 7 in formula (XI) is selected from H, halogen, OR (where R=H or alkyl), and OCOR (where R=alkyl or aryl);
[0077] R 15 and R 16 in formula (XII) are each selected from alkyl and aryl;
[0078] R 17 and R 18 in formula (XII) are each selected from H, alkyl, aryl, COOR (where R=H, alkyl or aryl), and CONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl);
[0079] R 19 and R 20 in formula (XII) are each selected from C 1 -C 4 alkyl, halogenated alkyl, and halogen; and
[0080] A in formula (XII) is selected from OTf, BF 4 , OAc, NO 3 , BPh 4 , PF 6 , and SbF 6 .
[0081] In another embodiment of the instant invention, a method of producing mostly 5β,6 62 -epoxides of steroids comprises epoxidation reactions of Δ 5 -unsaturated steroids of generic formula XIII catalyzed by ketones of generic formula XIV, XV, XVI, and XVII, wherein
[0082] X 2 in formula (XIII) is selected from the group consisting of H, OR (where R=H or alkyl), OCH 2 OCH 3 , OCOR (where R=alkyl or aryl), OSiR 1 ′R 2 ′R 3 ′ (where R 1 ′, R 2 ′ or R 3 ′=alkyl or aryl), halogen, CN, alkyl, aryl, and COOR (where R=H, alkyl or aryl), and,
[0083] X 3 in formula (XIII) is selected from the group consisting of OR (where R=H or alkyl), OCH 2 OCH 3 , OCOR (where R=alkyl or aryl), OSiR 1 ′R 2 ′R 3 ′ (where R 1 40 , R 2 ′ or R 3 ′=alkyl or aryl), halogen, CN, NO 2 , alkyl, and aryl; or,
[0084] X 2 and X 3 in formula (XIII) are selected from the group consisting of O, OCH 2 CH 2 O, and OCH 2 CH 2 CH 2 O;
[0085] R 8 in formula (XIII) is selected from H, OR (where R=H or alkyl), OCOR (where R=alkyl or aryl), OCH 2 OCH 3 , halogen, CF 3 , and CF 2 CF 3 ;
[0086] R 9 and R 10 in formula (XIII) are each selected from the group consisting of H, alkyl, aryl, halogen, OR (where R=H or alkyl), OCOR (where R=alkyl or aryl), OSiR 1 ′R 2 ′R 3 ′ (where R 1 ′, R 2 ′ or R 3 ′=alkyl or aryl), COR (where R=alkyl), COCH 2 OR (where R=H or alkyl), COCH 2 OCOR (where R=alkyl or aryl), COCH 2 F, COOR (where R=H or alkyl), C(OCH 2 CH 2 O)R (where R=alkyl), C(OCH 2 CH 2 O)CH 2 OR (where R=H or alkyl), C(OCH 2 CH 2 O)CH 2 OCOR (where R=alkyl or aryl), and C(OCH 2 CH 2 O)CH 2 F; or R 9 and R 10 in formula (XIII) are selected from the group consisting of O, OCH 2 CH 2 O, and OCH 2 CH 2 CH 2 O;
[0087] R 11 and R 12 in formula (XIII) are each selected from the group consisting of H, C 1 -C 4 alkyl halogen, OR (where R=H or alkyl), OCOR (where R=alkyl or aryl), and OSiR 1 ′R 2 ′R 3 ′ (where R 1 ′, R 2 ′ or R 3 ′=alkyl or aryl);
[0088] R 13 and R 14 in formula (XIII) are each selected from the group consisting of H, halogen, OR (where R=H or alkyl), and OCOR (where R=alkyl or aryl);
[0089] R 15 or R 16 in formula (XIV) is selected from alkyl and aryl;
[0090] R 17 or R 18 in formula (XIV) is selected from H, alkyl, aryl, COOR (where R=H, alkyl or aryl), and CONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl);
[0091] R 19 or R 20 in formula (XIV) is selected from H, C 1 -C 4 alkyl, halogenated alkyl, and halogen; and
[0092] A in formula (XIV) is selected from OTf, BF 4 , OAc, NO 3 , BPh 4 , PF 6 , and SbF 6 ;
[0093] Y in formula (XV) is selected from CH 2 , O, S, SO, SO 2 , and NR (where R=H or alkyl);
[0094] R 21 or R 22 in formula (XV) is selected from H, alkyl, aryl, COOR (where R=H, alkyl or aryl), and CONR 1 R 2 (where R 1 or R 2 =H, alkyl or aryl);
[0095] R 23 or R 24 in formula (XV) is selected from H, halogen, C 1 -C 4 alkyl, halogenated alkyl, and OCOR (where R=alkyl or aryl);
[0096] R 25 or R 26 in formula (XVI) is selected from C 1 -C 4 alkyl, halogenated alkyl, CH 2 OCOR (where R=alkyl or aryl); and
[0097] Z in formula (XVII) is selected from H, C 1 -C 4 alkyl, aryl, NO 2 , CN, F, Cl, Br, I, COOR (where R=alkyl), CH 2 OR (where R=H or alkyl), CH(OR) 2 (where R=alkyl), CF 3 , CF 2 CF 3 , OTf, OTs, OCOR (where R=alkyl or aryl), and OSiR 1 ′R 2 ′R 3 ′ (where R 1 ′, R 2 ′ or R 3 ′=alkyl or
[0098] In each of the disclosed embodiments, C 1 -C 4 alkyl can be selected from the group consisting of methyl, ethyl, normal-propyl, iso-propyl, normal-butyl, iso-butyl, sec-butyl, and tert-butyl; and said aryl can be selected from the group consisting of phenyl, substituted phenyl, naphthyl, and substituted naphthyl groups. The epoxidation reactions can be carried out in a homoogeneous solvent system selected from the group consisting of dimethoxymethane-acetonitrile-water, acetonitrile-water, acetone-water, dioxane-water, dimethoxyethane-water, and tetrahydrofuran-water, and mixtures thereof. Alternatively, the epoxidation reactions can be carried out in a biphasic solvent system selected from the group consisting of dichloromethane-water, chloroform-water, benzene-water, toluene-water, dimethoxymethane-water, or diethylether-water and mixtures thereof.
[0099] Suitable oxidation agents for the epoxidation reactions of the instant invention include potassium peroxomonosulfate, sodium hypochlorite, sodium perborate, hydrogen peroxide, and peracids.
[0100] The epoxidation reactions of the instant invention catalyzed by a ketone can be carried out at a temperature within the range from about −10° C. to about 40° C. Direct dioxirane epoxidation reactions of the instant invention can be carried out at a temperature within the range of from about −40° C. to about 40° C. Some epoxidation reactions of the instant invention can be carried out at about room temperature.
[0101] The epoxidation reactions of the instant invention can be carried out at a pH within the range from about 7.0 to about 12.0. Some such epoxidation reactions can be carried out at a pH within the range from about 7.0 to about 7.5. The pH can be controlled by using a pH-stat machine such as is known in the art, or a buffer. Suitable buffers include solutions of sodium bicarbonate, sodium carbonate, sodium borate, sodium hydrogenphosphate, sodium dihydrogenphosphate, sodium hydroxide, potassium hydrogenphosphate, potassium dihydrogenphosphate, potassium bicarbonate, potassium carbonate and potassium hydroxide.
[0102] We first examined four efficient ketone catalysts 1 - 4 for the in situ epoxidation of cholesterol 5 (FIG. 2). A modified homogeneous solvent system (a mixture of DMM/CH 3 CN/H 2 O in a 3:1:2 ratio) was used to increase the solubility of steroid substrates (FIG. 3). The results are summarized in Table 1. The ratio of β/α-epoxides was determined by integration of C(6) proton signals in the 1 H NMR spectra of the crude residues (δ3.00-3.15 ppm for β-epoxides and 67 2.75-2.95 ppm for α-epoxides). While ketones 1 - 3 exhibited poor β-selectivities (β/α epoxide ratio ca. 1:1; entries 1-3), ketone 4 with the most bulky α-substituent gave the best β-selectivity (β/α epoxide ratio 15.1:1; entry 4). A variety of 3β-substituted Δ 5 -steroids 6 - 10 (FIG. 2) were then subjected to the in situ epoxidation conditions with 20-30 mol % of ketone 4 . The results revealed that ketone 4 generally gave high β-selectivities (β/α epoxide ratio >8.5:1) and high yields (entries 4-10). It is interesting to note that Δ 5 -steroids with a free C3-OH group were directly converted to their 5β,6β-epoxides with high selectivity and yields (entries 4, 5, and 7-9). (Note: The free 3-OH group of Δ 5 -unsaturated steroids is not compatible with some metal-based oxidants in the epoxidation reactions.) Meanwhile, a wide range of functional groups such as hydroxyl, methoxyl, methoxymethyl ether, and carbonyl group were well tolerated under the mild and neutral reaction conditions (room temperature, pH 7-7.5).
[0103] Epoxidation reactions of 3α-substituted Δ 5 -steroids 11 - 20 were also carried out with ketone catalysts 1 - 4 (FIG. 2) and the ketone catalyst acetone. For epicholesterol 11 with a 3α-OH group, the epoxidation reactions catalyzed by ketones 1 and 4 gave much higher ,selectivities than those by ketones 2 and 3 (Table 2; entries 1-4) and acetone (see Table 3). This is because ketones 1 and 4 have larger α-substituents. For substrates with 3α-substituents larger than the OH group ( 12 - 20 ), the in situ epoxidation catalyzed by ketones 1 - 4 and acetone produced almost single 5β,6β-isomers (Table 2, β/α ratio>49:1, entries 5-24; Table 3). Substrates with 3-ketal group are of particular interest since highly α-selective epoxidation with trifluoroperacetic acid has been reported for this class of Δ 5 -steroids. Epoxidation of substrates 13 - 20 with mCPBA gave ca. 1:1 ratio of β/α-epoxides. The epoxidation reactions catalyzed by ketone 2 were highly efficient as only 5 mol % of the catalyst was needed even on a preparative scale. For example, a multi-gram scale (10 mmol) epoxidation of substrate 18 catalyzed by ketone 2 (5 mol %) provided almost a single β-epoxide (β/α-epoxide ratio>99:1) in 88% yield. These results clearly demonstrate the power of ketone-catalyzed epoxidation method.
[0104] In summary, we have developed a general, efficient and environmentally friendly method for highly β-selective epoxidation of Δ 5 -unsaturated steroids. With this method in hand, a library of 5β,6β-epoxides and their derivatives can be readily constructed and then screened for potential ligands that bind to orphan nuclear receptors. This is crucial for elucidating the biological functions of those receptors as well as for drug discovery.
General Experimental
[0105] The 1 H and 13 C NMR spectra (FIGS. 4 - 70 ) were recorded in deuteriochloroform (CDCl 3 ) with tetramethylsilane (TMS) as internal standard at ambient temperature on a Bruker Avance DPX 300 or 500 Fourier Transform Spectrometer. Infrared absorption spectra were recorded as a solution in CH 2 Cl 2 on a Bio-Rad FTS 165 Fourier Transform Spectrophotometer. Mass spectra were recorded with a Finningan MAT 95 mass spectrometer for both low resolution and high resolution mass spectra.
[0106] Substrates 5 , 6 , 8 , 9 , ketone 1 , tetrahydrothiopyran-4-one (precursor of ketone 2 ), and Oxone® were purchased from Aldrich or Acros Chemical Co. and used without further purification. Substrates 7 , 10 , 11 , 12 , 13 - 20 , and ketones 3 , 4 were prepared according to the literature procedures.
Typical Procedure for in situ Epoxidation Reactions
[0107] Epoxidation of Cholesterol 5 Catalyzed by Ketone 4 (Table 1, Entry 4). To a solution of cholesterol 5 (116 mg 0.3 mmol) and ketone 4 (41 mg, 0.09 mmol) in dimethoxymethane (DMM, 9 mL) and acetonitrile (CH 3 CN, 3 mL) at room temperature was added an aqueous Na 2 ·EDTA solution (6 mL, 4×10 −4 M). To this mixture was added in portions a mixture of Oxone® (922 mg, 1.5 mmol) and sodium bicarbonate (391 mg, 4.65 mmol) over the reaction period. The reaction mixture was poured into water, and extracted with ethyl acetate three times. The combined organic layers were dried over anhydrous MgSO 4 and filtered through a pad of silica gel. The ratio of α/β-epoxides was determined by 1 H NMR analysis of the crude residue which was obtained after removal of the solvent under reduced pressure. Pure products were obtained after flash column chromatography on silica gel (99 mg, 82% yield).
[0108] Epoxidation of Substrate 13 Catalyzed by Ketone 2 (Table 2, Entry 8). To a solution of substrate 13 (112 mg 0.3 mmol) and tetrahydrothiopyran-4-one (1.7 mg, 0.015 mmol) in dimethoxymethane (DMM, 9 mL) and acetonitrile (CH 3 CN, 3 mL) at room temperature was added an aqueous Na 2 . EDTA solution (6 mL, 4×10 −4 M). To this mixture was added in portions a mixture of Oxone® (922 mg, 1.5 mmol) and sodium bicarbonate (391 mg, 4.65 mmol) over a period of 1.5 h. The reaction was complete in 2 h as shown by TLC. The reaction mixture was poured into water, and extracted with ethyl acetate three times. The combined organic layers were dried over anhydrous MgSO 4 and filtered through a pad of silica gel. The ratio of α/β-epoxides was determined by 1 H NMR analysis of the crude residue which was obtained after removal of the solvent under reduced pressure. Pure epoxide was obtained after flash column chromatography on silica gel (110 mg, 94% yield).
Procedure for Preparative Scale Epoxidation Reactions
[0109] Epoxidation of Substrate 9 Catalyzed by Ketone 4 (Table 1, Entry 9). To a solution of substrate 9 (3.17 g 10 mmol) and ketone 4 (1.37 g, 3 mmol) in dimethoxymethane (DMM, 300 mL) and acetonitrile (CH 3 CN, 100 mL) at room temperature was added an aqueous Na 2 .EDTA solution (200 mL, 4×10 −4 M). To this mixture was added in portions a mixture of Oxone® (30.74 g, 50 mmol) and sodium bicarbonate (13.02 g, 155 mmol) over a period of 8 h. The reaction was complete in 10 h as shown by TLC. The reaction mixture was poured into water, and extracted with ethyl acetate three times. The combined organic layers were dried over anhydrous MgSO 4 and filtered through a pad of silica gel. The ratio of α/β-epoxides was determined by 1 H NMR analysis of the crude residue which was obtained after removal of the solvent under reduced pressure. Pure products were obtained after flash column chromatography on silica gel (2.86 g, 86% yield).
[0110] Epoxidation of Substrate 18 Catalyzed by Ketone 2 (Table 2, Entry 19). To a solution of substrate 18 (4.03 g 10 mmol) and tetrahydrothiopyran-4-one (58 mg, 0.5 mmol) in dimethoxymethane (DMM, 300 mL) and acetonitrile (CH 3 CN, 100 mL) at room temperature was added an aqueous Na 2 .EDTA solution (200 mL, 4×10 −4 M). To this mixture was added in portions a mixture of Oxone® (30.74 mg, 50 mmol) and sodium bicarbonate (13.02 g, 155 mmol) over a period of 4 h. The reaction was complete in 5 h as shown by TLC. The reaction mixture was poured into water, and extracted with ethyl acetate three times. The combined organic layers were dried over anhydrous MgSO 4 and filtered through a pad of silica gel. The ratio of α/β-epoxides was determined by 1 H NMR analysis of the crude residue which was obtained after removal of the solvent under reduced pressure. Pure epoxide was obtained after flash column chromatography on silica gel (3.68 g, 88% yield).
General Procedure for Epoxidation of Δ 5 -Unsaturated Steroids with mCPBA
[0111] Sodium bicarbonate (0.4 mmol) and mCPBA (0.2 mmol) were added to a solution of substrate (0.1 mmol) in CH 2 Cl 2 (3 ml). The resulting mixture was stirred at room temperature for 2 h and quenched with a solution of saturated aqueous Na 2 S 2 O 3 . The reaction mixture was diluted with ethyl acetate and washed with a solution of saturated aqueous NaHCO 3 and brine. The organic layer was dried over anhydrous MgSO 4 and filtered through a pad of silica gel. The product analysis was performed as above.
Characterization Data for Epoxides
[0112] [0112]
[0113] 5a and 5b (as a mixture of 1:15.1 ratio; Table 1, Entry 4):
[0114] [0114] 1 H NMR (300 MHz, CDCl 3 ) δ3.94-3.86 (m, 1/16.1×1H, 3α-H), 3.74-3.64 (m, 15.1/16.1×1H, 3α-H), 3.06 (d, J=2.2 Hz, 15.1/16.1×1H, 6α-H), 2.90 (d, J=4.3 Hz, 1/16.1×1H, 6β-H), 1.06 (s, 1/16.1×3H, 19-CH 3 ), 0.99 (s, 15.1/16.1×3H, 19-CH 3 ), 0.89 (d, J=6.6 Hz, 15.1/16.1×3H, 21-CH 3 ), 0.86 (d, J=6.6 Hz, 15.1/16.1×6H, 26-CH 3 and 27CH 3 ), 0.64 (s, 15.1/16.1×3H, 18-CH 3 ), 0.61 (s, 1/16.1×3H, 18-CH 3 ); 13 C NMR of 5b (75.5 MHz, CDCl 3 ) δ69.32, 63.76, 63.04, 56.21, 56.20, 51.32, 42.27, 42.18, 39.82, 39.48, 37.22, 36.12, 35.71, 34.84, 32.59, 30.97, 29.76, 28.14, 27.99, 24.18, 23.80, 22.81, 22.55, 21.98, 18.66, 17.05, 11.75.
[0115] 6a and 6b (as a mixture of 1:10.4 ratio; Table 1, Entry 5):
[0116] [0116] 1 H NMR (300 MHz, CDCl 3 ) δ3.95-3.85 (m, 1/11.4×1H, 3α-H), 3.76-3.65 (m, 10.4/11.4×1H, 3α-H), 3.13 (d, J=2.5 Hz, 10.4/11.4×1H, 6α-H), 2.95 (d, J=4.3 Hz, 1/11.4×1H, 6β-H), 1.09 (s, 1/11.4×3H, 19-CH 3 ), 1.03 (s, 10.4/11.4×3H, 19-CH 3 ), 0.85 (s, 10.4/11.4×3H, 18-CH 3 ) 0.82 (s, 1/11.4×3H, 18-CH 3 ); 13 C NMR of 6b (75.5 MHz, CDCl 3 ) δ220.97, 69.21 63.32, 63.05, 51.47, 51.18, 47.49, 42.05, 37.24, 35.74, 35.10, 31.51, 31.46, 30.93, 29.47, 21.73, 21.28, 17.08, 13.47.
[0117] 7a and 7b (as a mixture of 1:9; Table 1, Entry 6):
[0118] [0118] 1 H NMR (500 MHz, CDCl 3 ) δ=3.45-3.38 (m, 1/10×1H, 3α-H), 3.34 (s, 3H, OCH 3 ) 3.28-3.22 (m, 9/10×1H, 3α-H), 3.11 (d, J=2.4 Hz, 9/10×1H, 6α-H), 2.95 (d, J=4.4 Hz, 1/10×1H, 6β-H), 1.18 (s, 9/10×3H, 19-CH 3 ), 1.17 (s, 1/10×3H, 19-CH 3 ), 1.02 (s, 9/10×6H, 20-CH 3 and 21-CH 3 ), 0.87 (s, 9/10×3H, 18-CH 3 ), 0.85 (s, 1/10×3H, 18-CH 3 ); 13 C NMR of 9 b (75.5 MHz, CDCl 3 ) δ=225.00, 77.70, 63.15, 63.04, 55.71, 51.37, 48.52, 48.01, 45.15, 38.63, 37.82, 36.75, 35.54, 32.30, 31.66, 28.93, 27.27, 27.02, 25.95, 21.08, 17.13, 14.08; IR (CH 2 Cl 2 ) 1730 cm −1 ; LRMS (EI, 20 eV) m/z 346 (100), 314 (15), 123 (31), 108 (22); HRMS (EI, 20 eV) calcd for C 22 H 34 O 3 (M + ): 346.2508, found: 346.2508; Anal. Calcd for C 22 H 34 O 3 : C, 76.26; H, 9.89; Found: C, 76.14; H, 9.90.
[0119] 8a and 8b (as a mixture of 1:8.8 ratio; Table 1, Entry 7):
[0120] [0120] 1 H NMR (300 MHz, CDCl 3 ) δ3.95-3.84 (m, 1/9.8×1H, 3α-H), 3.74-3.64 (m, 8.8/9.8×1H, 3α-H), 3.60 (t, J=8.5 Hz, 1H, 17α-H), 3.07 (d, J=2.4 Hz, 8.8/9.8×1H, 6α-H), 2.91 (d, J=4.4 Hz, 1/9.8×1H, 6β-H), 1.07 (s, 1/9.8×3H, 19-CH 3 ), 1.01 (s, 8.8/9.8×3H, 19-Ch 3 ), 0.72 (s, 8.8/9.8×3H, 18-CH 3 ), 0.69 (s, 1/9.8×3H, 18-CH 3 ); 13 C NMR of 8 b (75.5 MHz, CDCl 3 ) δ81.81, 69.31, 63.51, 63.01, 51.48, 50.74, 42.67, 42.15, 37.25, 36.62, 34.99, 32.19, 30.97, 30.42, 29.81, 23.31, 21.60, 17.12, 10.86.
[0121] 9a and 9b (as a mixture of 1:11.6; Table 1, Entry 8):
[0122] [0122] 1 H NMR (300 MHz, CDCl 3 ) δ3.94-3.87 (m, 1/12.6×1H, 3α-H), 3.75-3.65 (m, 11.6/12.6×1H, 3α-H), 3.08 (d, J=2.3 Hz, 11.6/12.6×1H, 6α-H), 2.92 (d, J=4.4 Hz, 1/12.6×1H, 6β-H), 2.11 (s, 11.6/12.6×3H, 21-CH 3 ) 1.06 (s, 1/12.6×3H, 19-CH 3 ), 1.00 (s, 11.6/12.6×3H, 19-CH 3 ), 0.59 (s, 11.6/12.6×3H, 18-CH 3 ) 0.56 (s, 1/12.6×3H, 18-CH 3 ); 13 C NMR of 9b (75.5 MHz, CDCl 3 ) δ209.48, 69.29, 63.67, 63.50, 62.89, 56.33, 51.19, 43.89, 42.12, 38.84, 4.92, 32.51, 31.46, 30.97, 29.76, 24.36, 22.77, 21.96, 17.07, 13.11.
[0123] 10a and 10b (as a mixture of: 18.5; Table 1, Entry 10):
[0124] [0124] 1 H NMR (300 MHz, CDCl 3 ) δ4.73-4.64 (m, 2H, OCH 2 O), 3.83-3.74 (m, 1/9.5×1H, 3α-H), 3.65-3.55 (m, 8.5/9.5×1H, 3α-H), 3.36 (s, 8.5/9.5×3H, OCH 3 ), 3.35 (s, 1/9.5×3H, OCH 3 ), 3.08 (d, J=2.3 Hz, 8.5/9.5×1H, 6α-H), 2.91 (d, J=4.3 Hz, 1/9.5×1H, 6α-H), 2.11 (s, 8.5/9.5×3H, 21-CH 3 ), 1.06 (s, 1/9.5×3H, 19-CH 3 ), 1.00 (s, 8.5/9.5×3H, 19-CH 3 ), 0.60 (s, 8.5/9.5×3H, 18-CH 3 ), 0.56 (s, 1/9.5×3H, 18-CH 3 ); 13 C NMR of 11 b (75.5 MHz, CDCl 3 ) δ209.35, 94.67, 74.18, 63.67, 63.44, 62.82, 56.33, 55.26, 51.08, 43.88, 39.43, 38.84, 37.07, 35.16, 32.48, 31.45, 29.74, 28.13, 24.35, 22.77, 21.94, 17.07, 13.11; IR (CH 2 Cl 2 ) 1700 cm −1 ; EIMS (20 eV) m/z 376 (100), 314 (90), 133 (36), 95 (33); HRMS (EI, 20 eV) calcd for C 23 H 36 O 4 (M + ): 376.2614, found: 376.2617; Anal. Calcd for C 23 H 36 O 4 : C, 73.37; H, 9.64; Found: C, 73.11; H, 9.68.
[0125] 11b:
[0126] [0126] 1 H NMR (300 MHz, CDCl 3 ) δ4.19 (br s, 1H, 3α-H), 3.07 (d, J=2.0 Hz, 1H, 6α-H), 0.97 (s, 3H, 19-CH 3 ), 0.89 (d, J=6.6 Hz, 3H, 21-CH 3 ), 0.86 (d, J=6.6 Hz, 6H, 26-CH 3 and 27-CH 3 ), 0.64 (s, 3H, 18-CH 3 ); 13 C NMR (75.5 MHz, CDCl 3 ) δ67.03, 63.70, 61.97, 56.31, 56.20, 50.38, 42.31, 39.87, 39.86, 39.49, 36.14, 35.74, 35.53, 33.19, 32.37, 29.82, 28.40, 28.17, 27.99, 24.18, 23.83, 22.81, 22.55, 21.69, 18.67, 17.00, 11.78.
[0127] 11a:
[0128] [0128] 1 H NMR (300 MHz, CDCl 3 ) δ4.10-4.07 (m, 1H, 3β-H), 2.87 (d, J=4.5 Hz, 1H, 6β-H), 1.04 (s, 3H, 19-CH 3 ), 0.89 (d, J=6.6 Hz, 3H, 21-CH 3 ), 0.86 (d, J=6.6 Hz, 6H, 26-CH 3 and 27-CH 3 ), 0.61 (s, 3H, 18-CH 3 ); 13 C NMR (75.5 MHz, CDCl 3 ) δ67.98, 65.43, 57.79, 56.86, 55.84, 42.66, 42.32, 39.49, 39.36, 36.41, 36.13, 35.76, 35.52, 29.62, 28.92, 28.63, 28.59, 28.07, 28.00, 24.02, 23.84, 22.82, 22.56, 20.28, 18.64, 15.34, 11.86.
[0129] 12b:
[0130] [0130] 1 H NMR (300 MHz, CDCl 3 ) δ5.12-5.10 (m, 1H, 3β-H), 3.00 (d, J=2.0 Hz, 1H, 6α-H), 2.04 (s, 3H, CH 3 COO), 0.99 (s, 3H, 19-CH 3 ), 0.89 (d, J=6.6 Hz, 3H, 21-CH 3 ), 0.86 (d, J=6.6 Hz, 6H, 26-CH 3 and 27-CH 3 ), 0.65 (s, 3H, 18-CH 3 ); 13 C NMR (75.5 MHz, CDCl 3 ) δ170.52, 70.50, 63.28, 61.69, 56.33, 56.27, 50.20, 42.34, 39.86, 39.49, 36.63, 36.15, 35.76, 35.43, 33.78, 32.43, 29.81, 28.19, 28.01, 25.47, 24.19, 23.85, 22.82, 22.56, 21.71, 21.34, 18.68, 17.13, 11.78.
[0131] 13b:
[0132] [0132] 1 H NMR (300 MHz, CDCl 3 ) δ3.97-3.79 (m, 8H, OCH 2 CH 2 O), 3.06 (d, J=2.1 Hz, 1H, 6α-H), 1.00 (s, 3H, 19-CH 3 ), 0.82 (s, 3H, 18-CH 3 ); 3 C NMR (75.5 MHz, CDCl 3 ) δ119.12, 109.19, 64.97, 64.33, 64.12, 63.94, 62.90, 62.76, 49.81, 49.53, 45.50, 41.29, 35.43, 34.97, 33.91, 31.44, 30.64, 30.38, 29.78, 22.44, 21.20, 16.94, 13.96.
[0133] 14b:
[0134] [0134] 1 H NMR (300 MHz, CDCl 3 ) δ3.97-3.85 (m, 4H, OCH 2 CH 2 O), 3.05 (d, J=1.9 Hz, 1H, 6α-H), 0.99 (s, 3H, 19-CH 3 ), 0.89 (d, J=6.7 Hz, 3H, 21-CH 3 ), 0.86 (d, J=6.6 Hz, 6H, 26-CH 3 and 27-CH 3 ), 0.64 (s, 3H, 18-CH 3 ); 13 C NMR (75.5 MHz, CDCl 3 ) δ109.45, 64.27, 64.09, 63.29, 56.24, 56.15, 49.85, 42.28, 41.46, 39.81, 39.47, 36.11, 35.71, 35.61, 35.01, 32.27, 30.82, 29.67, 28.15, 27.98, 24.16, 23.79, 22.81, 22.54, 21.89, 18.66, 17.06, 11.75.
[0135] 15b:
[0136] [0136] 1 H NMR (300 MHz, CDCl 3 ) δ3.97-3.87 (m, 4H, OCH 2 CH 2 O), 3.60 (t, J=8.5 Hz, 1H, 17α-H), 3.07 (d, J=2.2 Hz, 1H, 6α-H), 1.01 (s, 3H, 19-CH 3 ), 0.72 (s, 3H, 18-CH 3 ); 13 C NMR (75.5 MHz, CDCl 3 ) δ109.41, 81.78, 64.31, 64.14, 63.14, 63.05, 50.79, 50.07, 42.70, 41.45, 36.63, 35.66, 35.17, 31.87, 30.81, 30.45, 29.73, 23.31, 21.53, 17.14, 10.88.
[0137] 16b:
[0138] [0138] 1 H NMR (300 MHz, CDCl 3 ) δ4.56 (dd, J=9.0, 7.9 Hz, 1H, 17α-H), 3.95-3.89 (m, 4H, OCH 2 CH 2 O), 3.07 (d, J=2.2 Hz, 1H, 6α-H), 2.03 (s, 3H, CH 3 COO), 1.00 (s, 3H, 19-CH 3 ), 0.77 (s, 3H, 18-CH 3 ); 13 C NMR (75.5 MHz, CDCl 3 ) δ171.20, 109.34, 82.64, 64.30, 64.14, 63.09, 63.00 50.53, 49.94, 42.33, 41.45, 36.79, 35.68, 35.14, 31.85, 30.78, 29.52, 27.43, 23.44, 21.39, 21.15, 17.11, 11.84.
[0139] 17b:
[0140] [0140] 1 H NMR (300 MHz, CDCl 3 ) δ3.95-3.90 (m, 4H, OCH 2 CH 2 O), 3.07 (d, J=2.1 Hz, 1H, 6α-H), 2.11 (s, 3H, 21-CH 3 ), 1.00 (s, 3H, 19-CH 3 ), 0.60 (s, 3H, 18-CH 3 ); 13 C NMR (75.5 MHz, CDCl 3 ) δ209.41, 109.37, 64.33, 64.16, 63.66, 63.15, 62.95, 56.40, 49.84, 43.92, 41.42, 38.85, 35.71, 35.10, 32.21, 31.47, 30.82, 29.70, 24.36, 22.78, 21.90, 17.09, 13.12.
[0141] [0141] 18 b:
[0142] [0142] 1 H NMR (300 MHz, CDCl 3 ) δ4.04-3.81 (m, 8H, OCH 2 CH 2 O), 3.06 (d, J=1.8 Hz, 1H, 6α-H),1.28 (s, 3H, 21-CH 3 ), 1.00 (s, 3H, 19-CH 3 ), 0.74 (s, 3H, 18-CH 3 ); 13 -C NMR (75.5 MHz, CDCl 3 ) δ111.85, 109.44, 65.16, 64.29, 64.12, 63.26, 63.19, 63.00, 58.21, 56.12, 49.87, 41.75, 9.44, 35.62, 35.06, 32.18, 30.82, 29.22, 24.54, 23.70, 22.90, 21.67, 17.10, 12.76.
[0143] 19b:
[0144] [0144] 1 H NMR (300 MHz, CDCl 3 ) δ4.03-3.81 (m, 9H, 11β-H and OCH 2 CH 2 O), 3.08 (d, J=2.6 Hz1H, 6α-H), 1.28 (s, 3H, 21-CH 3 ), 1.20 (s, 3H, 19-CH 3 ), 0.76 (s, 3H, 18-CH 3 ); 13 C NMR (75.5 MHz, CDCl 3 ) δ111.47, 109.02, 68.68, 64.98, 64.17, 64.04, 63.35, 63.10, 62.90, 57.80, 57.01, 55.22, 50.60, 42.45, 41.81, 37.41, 35.87, 31.40, 30.57, 27.91, 24.40, 23.42, 22.97, 15.55, 13.86.
[0145] 20b:
[0146] [0146] 1 H NMR (300 MHz, CDCl 3 ) δ5.07 (td, J=10.9, 4.8 Hz, 1H, 11β-H), 3.99-3.83 (m, 8H, OCH 2 CH 2 O), 3.08 (d, J=2.7 Hz, 1H, 6α-H), 2.01 (s, 3H, CH 3 COO), 1.24 (s, 3H, 21-CH 3 ), 1.02 (s, 3H, 19-CH 3 ), 0.82 (s, 3H, 18-CH 3 ); 13 C NMR (75.5 MHz, CDCl 3 ) δ169.76, 111.42, 108.87, 72.38, 64.96, 64.28, 64.17, 63.16, 63.02, 62.69, 57.73, 55.09, 53.57, 45.36, 42.23, 41.86, 37.02, 35.85, 31.56, 30.70, 28.09, 24.46, 23.52, 23.19, 21.87, 16.06, 13.58.
Determination of the Ratio of β/α-epoxides
[0147] The ratio of β/α-epoxides was determined by integration of the C(6) proton signals in the 1 H NMR spetra (300 or 500 MHz) of crude residues (δ3.00-3.15 ppm for β-epoxides and δ 2.75-2.95 ppm for α-epoxides). The authentic samples of 5a/5b-20a/20b were prepared by epoxidation of substrates 5 - 20 with mCPBA according to the literature procedure.
EXAMPLES
Example 1
5β,6β-Epoxycholestan-3β-ol (Catalyzed by Ketone 4 )
[0148] To a solution of cholesterol (116 mg 0.3 mmol) and ketone 4 (41 mg, 0.09 mmol) in dimethoxymethane (9 mL) and acetonitrile (3 mL) at room temperature was added an aqueous Na 2 .EDTA solution (6 mL, 4×10 −4 M). To this mixture was added in portions a mixture of Oxone® (922 mg, 1.5 mmol) and sodium bicarbonate (391 mg, 4.65 mmol) over the reaction period. The reaction mixture was poured into water, and extracted with ethyl acetate three times. The combined organic layers were dried over anhydrous MgSO 4 and filtered through a pad of silica gel. 1 H NMR analysis of the product showed that the ratio of β/α-epoxides was 15.1:1. Pure products were obtained after flash column chromatography on silica gel (99 mg, 82% yield).
Example 2
5β,6β-Epoxyandrostene-3,17-dione 3,17-diethylene Ketal (Catalyzed by Ketone 1 )
[0149] To a solution of 5-androstene-3,17-dione 3,17-diethylene ketal (112 mg 0.3 mmol) in dimethoxymethane (9 mL) and acetonitrile (3 mL) was added an aqueous Na 2 ·EDTA solution (6 mL, 4×10 −4 M), the resulting solution was cooled to 0-1° C., followed by addition of 1,1,1-trifluoroacetone (0.54 mL, 6 mmol). To this solution was added in portions a mixture of Oxone® (922 mg, 1.5 mmol) and sodium bicarbonate (391 mg, 4.65 mmol) over a period of 0.5 h. The reaction was complete in 1 h as shown by TLC. The reaction mixture was poured into water, and extracted with ethyl acetate three times. The combined organic layers were dried over anhydrous MgSO 4 and filtered through a pad of silica gel. 1 H NMR analysis of the crude residue showed that the ratio of β/α-epoxides was >99:1. 5β,6β-Epoxyandrostene-3,17-dione 3,17-diethylene ketal was obtained after flash column chromatography on silica gel (101 mg, 86% yield).
Example 3
5β,6β-Epoxyandrostene-3,17-dione 3,17-diethylene Ketal (Catalyzed by Ketone 2 )
[0150] To a solution of 5-androstene-3,17-dione 3,17-diethylene ketal (112 mg 0.3 mmol) and tetrahydrothiopyran-4-one (1.7 mg, 0.015 mmol) in dimethoxymethane (9 mL) and acetonitrile (3 mL) at room temperature was added an aqueous Na 2 .EDTA solution (6 mL, 4×10 −4 M). To this mixture was added in portions a mixture of Oxone® (922 mg, 1.5 mmol) and sodium bicarbonate (391 mg, 4.65 mmol) over a period of 1.5 h. The reaction was complete in 2 h as shown by TLC. The reaction mixture was poured into water, and extracted with ethyl acetate three times. The combined organic layers were dried over anhydrous MgSO 4 and filtered through a pad of silica gel. 1 H NMR analysis of the crude residue showed that the ratio of β/α-epoxides was 96:1. 5β,6β-Epoxyandrostene-3,17-dione 3,17-diethylene ketal was obtained after flash column chromatography on silica gel (110 mg, 94% yield).
Example 4
5β,6β-Epoxyandrostene-3,17-dione 3,17-diethylene Ketal (Catalyzed by Ketone 3 )
[0151] To a solution of 5-androstene-3,17-dione 3,17-diethylene ketal (112 mg 0.3 mmol) and ketone 3 (9 mg, 0.03 mmol) in dimethoxymethane (9 mL) and acetonitrile (3 mL) at room temperature was added an aqueous Na 2 ·EDTA solution (6 mL, 4×10 −4 M). To this mixture was added in portions a mixture of Oxone® (922 mg, 1.5 mmol) and sodium bicarbonate (391 mg, 4.65 mmol) over a period of 1 h. The reaction was complete in 1.5 h as shown by TLC. The reaction mixture was poured into water, and extracted with ethyl acetate three times. The combined organic layers were dried over anhydrous MgSO 4 and filtered through a pad of silica gel. 1 H NMR analysis of the crude residue showed that the ratio of β/α-epoxides was 49:1. 5β,6β-Epoxyandrostene-3,17-dione 3,17-diethylene ketal was obtained after flash column chromatography on silica gel (109 mg, 93% yield).
Example 5
5β,6β-Epoxyandrostene-3,17-dione 3,17-diethylene Ketal (Catalyzed by Acetone)
[0152] To a solution of 5-androstene-3,17-dione 3,17-diethylene ketal (112 mg 0.3 mmol) and acetone (522 mg, 9 mmol) in dimethoxymethane (9 mL) and acetonitrile (3 mL) at room temperature was added an aqueous Na 2 ·EDTA solution (6 mL, 4×10 −4 M). To this mixture was added in portions a mixture of Oxone® (922 mg, 1.5 mmol) and sodium bicarbonate (391 mg, 4.65 mmol) over a period of 4 h. The reaction was complete in 5 h as shown by TLC. The reaction mixture was poured into water, and extracted with ethyl acetate three times. The combined organic layers were dried over anhydrous MgSO 4 and filtered through a pad of silica gel. 1 H NMR analysis of the crude residue showed that the ratio of β/α-epoxides was >99:1. 5β,6β-Epoxyandrostene-3,17-dione 3,17-diethylene ketal was obtained after flash column chromatography on silica gel (110 mg, 94% yield).
Example 6
5β,6β-Epoxyandrostene-3,17-dione 3,17-diethylene Ketal (Acetone as Catalyst and Cosolvent)
[0153] To a solution of 5-androstene-3,17-dione 3,17-diethylene ketal (112 mg 0.3 mmol) in actone (15 mL) at room temperature was added an aqueous Na 2 .EDTA solution (5 mL, 4×10 −4 M). To this mixture was added in portions a mixture of Oxone® (922 mg, 1.5 mmol) and sodium bicarbonate (391 mg, 4.65 mmol) over a period of 1.5 h. The reaction was complete in 2 h as shown by TLC. The reaction mixture was poured into water, and extracted with ethyl acetate three times. The combined organic layers were dried over anhydrous MgSO 4 and filtered through a pad of silica gel. 1 H NMR analysis of the crude residue showed that the ratio of β/α-epoxides was >99:1. 5β,6β-Epoxyandrostene-3,17-dione 3,17-diethylene ketal was obtained after flash column chromatography on silica gel (105 mg, 90% yield).
Example 7
5β,6β-Epoxy-3β-Hydroxypregnan-20-one (Catalyzed by Ketone 4 )
[0154] To a solution of pregnenolone (3.17 g 10 mmol) and ketone 4 (1.37 g, 3 mmol) in dimethoxymethane (300 mL) and acetonitrile (100 mL) at room temperature was added an aqueous Na 2 .EDTA solution (200 mL, 4×10 −4 M). To this mixture was added in portions a mixture of Oxone® (30.74 g, 50 mmol) and sodium bicarbonate (13.02 g, 155 mmol) over a period of 8 h. The reaction was complete in 10 h as shown by TLC. The reaction mixture was poured into water, and extracted with ethyl acetate three times. The combined organic layers were dried over anhydrous MgSO 4 and filtered through a pad of silica gel. 1 H NMR analysis of the product showed that he ratio of β/α-epoxides was 16.0:1. Pure products were obtained after flash column chromatography on silica gel (2.86 g, 86% yield).
Example 8
5β,6β-Epoxy-11α-hydroxypregnene-3,20-dione 3-diethylene Ketal (Catalyzed by Ketone 2 )
[0155] To a solution of 5-pregnene-3,20-dione 3,20-diethylene ketal (4.03 g 10 mmol) and tetrahydrothiopyran-4-one (58 mg, 0.5 mmol) in dimethoxymethane (300 mL) and acetonitrile (100 mL) at room temperature was added an aqueous Na 2 ·EDTA solution (200 mL, 4×10 −4 M). To this mixture was added in portions a mixture of Oxone® (30.74 mg, 50 mmol) and sodium bicarbonate (13.02 g, 155 mmol) over a period of 4 h. The reaction was complete in 5 h as shown by TLC. The reaction mixture was poured into water, and extracted with ethyl acetate three times. The combined organic layers were dried over anhydrous MgSO 4 and filtered through a pad of silica gel. 1 H NMR analysis of the crude residue showed that the ratio of β/α-epoxides was >99:1. 5β,6β-Epoxypregnene-3,20-dione 3,20-diethylene ketal was obtained after flash column chromatography on silica gel (3.68 g, 88% yield).
Example 9
5β,6β-Epoxy-3β-hydroxyandrostan-17-one (Catalyzed by Ketone 4 )
[0156] Following the procedure of Example 1 above, dehydroisoandrosterone was epoxidized to 5β,6β-epoxy-3β-hydroxyandrostan-17-one.
Example 10
5β,6β-Epoxy-16,16-dimethyl-3β-methoxyandrostan-17-one (Catalyzed by Ketone 4 )
[0157] Following the procedure of Example 1 above, 16,16-dimethyl-3β-methoxy-5-androsten-17-one was epoxidized to 5β,6β-epoxy-16,16-dimethyl-3β-methoxyandrostan-17-one.
Example 11
5β,6β-Epoxyandrostane-3β,17β-diol (Catalyzed by Ketone 4 )
[0158] Following the procedure of Example 1 above, 5-androstene-3β,17β-diol was epoxidized to 5β,6β-epoxyandrostane-3β,17β-diol.
Example 12
5β,6β-Epoxy-3β-methoxymethoxypregnan-20-one (Catalyzed by Ketone 4 )
[0159] Following the procedure of Example 1 above, 3β-methoxymethoxy-5-pregnen-20-one was epoxidized to 5β,6β-epoxy-3β-methoxymethoxypregnan-20-one.
Example 13
5β,6β-Epoxycholestan-3α-ol (Catalyzed by Ketone 4 )
[0160] Following the procedure of Example 1 above, epicholesterol was epoxidized to 5β,6β-epoxycholestan-3α-ol.
Example 14
5β,6β-Epoxy-3β-acetoxycholestane (Catalyzed by Ketone 2 )
[0161] Following the procedure of Example 3 above, 3α-acetoxycholest-5-ene was epoxidized to 5β,6β-epoxy-3α-acetoxycholestane.
Example 15
5β,6β-Epoxy-3α-acetoxycholestane (Catalyzed by Ketone 4 )
[0162] Following the procedure of Example 1 above, 3α-acetoxycholest-5-ene was epoxidized to 5β,6β-epoxy-3α-acetoxycholestane.
Example 16
5β,6β-Epoxycholestane-3-one 3-ethylene Ketal (Catalyzed by Ketone 2 )
[0163] Following the procedure of Example 3 above, 5-cholestene-3-one 3-ethylene ketal was epoxidized to 5β,6β-epoxycholestane-3-one 3-ethylene ketal.
Example 17
5β,6β-Epoxycholestane-3-one 3-ethylene Ketal (Catalyzed by Ketone 4 )
[0164] Following the procedure of Example 1 above, 5-cholestene-3-one 3-ethylene ketal was epoxidized to 5β,6β-epoxycholestane-3-one 3-ethylene ketal.
Example 18
5β,6β-Epoxy-17β-hydroxyandrostan-3-one 3-ethylene Ketal (Catalyzed by Ketone 2 )
[0165] Following the procedure of Example 3 above, 17β-hydroxyandrost-5-en-3-one 3-ethylene ketal was epoxidized to 5β,6β-epoxy-17β-hydroxyandrostan-3-one 3-ethylene ketal.
Example 19
5β,6β-Epoxy-17β-hydroxyandrostan-3-one 3-ethylene Ketal (Catalyzed by Ketone 4 )
[0166] Following the procedure of Example 1 above, 17β-hydroxyandrost-5-en-3-one 3-ethylene ketal was epoxidized to 5β,6β-epoxy-17β-hydroxyandrostan-3-one 3-ethylene ketal.
Example 20
5β,6β-Epoxy-17β-acetoxyandrostan-3-one 3-ethylene Ketal (Catalyzed by Ketone 2 )
[0167] Following the procedure of Example 3 above, 17β-acetoxyandrost-5-en-3-one 3-ethylene ketal was epoxidized to 5β,6β-epoxy-17β-acetoxyandrostan-3-one 3-ethylene ketal.
Example 21
5β,6β-Epoxy-17β-acetoxyandrostan-3-one 3-ethylene Ketal (Catalyzed by Ketone 4 )
[0168] Following the procedure of Example 1 above, 17β-acetoxyandrost-5-en-3-one 3-ethylene ketal was epoxidized to 5β,6β-epoxy-17β-acetoxyandrostan-3-one 3-ethylene ketal.
Example 22
5β,6β-Epoxypregnene-3,20-dione 3,20-diethylene Ketal (Catalyzed by Ketone 2 )
[0169] Following the procedure of Example 3 above, 5-pregnene-3,20-dione 3,20-diethylene ketal was epoxidized to 5β,6β-epoxypregnene-3,20-dione 3,20-diethylene ketal.
Example 23
5β,6β-Epoxypregnene-3,20-dione 3,20-diethylene Ketal (Catalyzed by Ketone 4 )
[0170] Following the procedure of Example 1 above, 5-pregnene-3,20-dione 3,20-diethylene ketal was epoxidized to 5β,6β-epoxypregnene-3,20-dione 3,20-diethylene ketal.
Example 24
5β,6β-Epoxypregnene-3,20-dione 3-diethylene Ketal (Catalyzed by Ketone 2 )
[0171] Following the procedure of Example 3 above, 5-pregnene-3,20-dione 3-ethylene ketal was epoxidized to 5β,6β-epoxypregnene-3,20-dione 3-ethylene ketal.
Example 25
5β,6β-Epoxypregnene-3,20-dione 3-diethylene Ketal (Catalyzed by Ketone 4 )
[0172] Following the procedure of Example 1 above, 5-pregnene-3,20-dione 3-ethylene ketal was epoxidized to 5β,6β-epoxypregnene-3,20-dione 3-ethylene ketal.
Example 26
5β,6β-Epoxy-11α-hydroxypregnene-3,20-dione 3-diethylene Ketal (Catalyzed by Ketone 2 )
[0173] Following the procedure of Example 3 above, 11α-hydroxy-5-pregnene-3,20-dione 3-ethylene ketal was epoxidized to 5β,6β-epoxy-11α-hydroxypregnene-3,20-dione 3-diethylene ketal.
Example 27
5β,6β-Epoxy-11α-hydroxypregnene-3,20-dione 3-diethylene Ketal (Catalyzed by Ketone 4 )
[0174] Following the procedure of Example 1 above, 11α-hydroxy-5-pregnene-3,20-dione 3-ethylene ketal was epoxidzed to 5β,6β-epoxy-11α-hydroxypregnene-3,20-dione 3-diethylene ketal.
Example 28
5β,6β-Epoxy-11α-acetoxypregnene-3,20-dione 3-diethylene Ketal (Catalyzed by Ketone 2 )
[0175] Following the procedure of Example 3 above, 11α-acetoxy-5-pregnene-3,20-dione 3-ethylene ketal was epoxidized to 5β,6β-epoxy-11α-acetoxypregnene-3,20-dione 3-diethylene ketal.
Example 29
5β,6β-Epoxy-11α-acetoxypregnene-3,20-dione 3-diethylene Ketal (Catalyzed by Ketone 4 )
[0176] Following the procedure of Example 1 above, 11α-acetoxy-5-pregnene-3,20-dione 3-ethylene ketal was epoxidized to 5β,6β-epoxy-11α-acetoxypregnene-3,20-dione 3-diethylene ketal.
Example 30
5β,6β-Epoxycholestan-3α-ol (catalyzed by Ketone 1 )
[0177] Following the procedure of Example 2 above, epi-cholesterol was epoxidized to 5β,6β-epoxycholestan-3α-ol.
Example 31
5β,6β-Epoxyandrostene-3,17-dione 3,17-diethylene Ketal (Catalyzed by Ketone 4 )
[0178] Following the procedure of Example 1 above 5-cholestene-3-one 3-ethylene ketal was epoxidized to 5β,6β-epoxyandrostene-3,17-dione 3,17-diethylene ketal.
Example 32
5β,6β-Epoxycholestane-3-one 3-ethylene Ketal (Catalyzed by Acetone)
[0179] Following the procedure of Example 5 above, 5-cholestene-3-one 3-ethylene ketal was epoxidized to 5β,6β-epoxycholestane-3-one 3-ethylene ketal.
Example 33
5β,6β-Epoxy-17β-acetoxyandrostan-3-one 3-ethylene Ketal (Catalyzed by Acetone)
[0180] Following the procedure of Example 5 above, 17β-acetoxyandrost-5-en-3-one 3-ethylene ketal was epoxidized to 5β,6β-epoxy-17β-acetoxyandrostan-3-one 3-ethylene ketal.
Example 34
5β,6β-Epoxypregnene-3,20-dione 3-ethylene Ketal (Catalyzed by Ketone 2 )
[0181] Following the procedure of Example 3 above, 5-pregnene-3,20-dione 3-ethylene ketal was epoxidized to 5β,6β-epoxypregnene-3,20-dione 3-ethylene ketal.
Example 35
5β,6β-Epoxypregnene-3,20-dione 3-ethylene Ketal (Catalyzed by Ketone 4 )
[0182] Following the procedure of Example 1 above, 5-pregnene-3,20-dione 3-ethylene ketal was epoxidized to 5β,6β-epoxypregnene-3,20-dione 3-ethylene ketal.
Example 36
5β,6β-Epoxypregnene-3,20-dione 3,20-diethylene Ketal (Catalyzed by Acetone)
[0183] Following the procedure of Example 5 above, 5-pregnene-3,20-dione 3,20-diethylene ketal was epoxidized to 5β,6β-epoxypregnene-3,20-dione 3,20-diethylene ketal.
Example 37
5β,6,-Epoxy-11α-hyrdoxypregnene-3,20-dione 3,20-diethylene Ketal (Catalyzed by Acetone)
[0184] Following the procedure of Example 5 above, 11α-hyrdoxy-5-pregnene-3,20-dione 3,20-diethylene ketal was epoxidized to 5β,6β-epoxy-11α-hyrdoxypregnene-3,20-dione 3,20-diethylene ketal.
Example 38
5β,6β-Epoxy-11α-hyrdoxypregnene-3,20-dione 3,20-diethylene Ketal (Catalyzed by Ketone 2 )
[0185] Following the procedure of Example 3 above, 11α-hyrdoxy-5-pregnene-3,20-dione 3,20-diethylene ketal was epoxidized to 5β,6β-epoxy-11α-hyrdoxypregnene-3,20-dione 3,20-diethylene ketal.
Example 39
5β,6β-Epoxy-11α-hyrdoxypregnene-3,20-dione 3,20-diethylene Ketal (Catalyzed by Ketone 4 )
[0186] Following the procedure of Example 1 above, 11α-hyrdoxy-5-pregnene-3,20-dione 3,20-diethylene ketal was epoxidized to 5β,6β-epoxy-11α-hyrdoxypregnene-3,20-dione 3,20-diethylene ketal.
Example 40
5β,6β-Epoxy-11α-acetoxypregnene-3,20-dione 3,20-diethylene Ketal (Catalyzed by Ketone 2 )
[0187] Following the procedure of Example 3 above, 11α-acetoxy-5-pregnene-3,20-dione 3,20-diethylene ketal was epoxidized to 5β,6β-epoxy-11α-acetoxypregnene-3,20-dione 3,20-diethylene ketal.
Example 41
5β,6β-Epoxy-11α-acetoxypregnene-3,20-dione 3,20-diethylene Ketal (Catalyzed by Ketone 4 )
[0188] Following the procedure of Example 1 above, 11α-acetoxy-5-pregnene-3,20-dione 3,20-diethylene ketal was epoxidized to 5β,6β-epoxy-11α-acetoxypregnene-3,20-dione 3,20-diethylene ketal.
[0189] The invention has been described with reference to preferred embodiments. Those skilled in the art will perceive improvements, changes and modifications. Such improvements, changes and modifications are intended to be within the scope of the claims.
TABLE 1 Stereoselective epoxidation of 3β-substituted Δ 5 -steroids by dioxiranes generated in situ. a catalyst reaction ketone loading time yield β/α-epoxide entry catalyst substrate (equivalent) (h) b (%) c ratio d,e 1 1 f 5 20 1.5 91 1/1.1 (1/4.0) 2 2 5 0.05 1.5 93 1.1/1 3 3 5 0.1 3 92 1/1.1 4 4 5 0.3 16 82 15.1/1 5 4 6 0.2 9 91 10.4/1 (1/3.9) 6 4 7 0.2 20 88 9.0/1 (1/3.1) 7 4 8 0.2 16 85 8.8/1 (1/3.1) 8 4 9 0.2 9 93 11.6/1 (1/4.3) 9 g 4 9 0.3 10 86 16.0/1 10 4 10 0.2 20 83 8.5/1 (1/3.7)
[0190] Note: An additional experiment was performed using ketone 4 and substrate 9 in which the catalyst loading and reaction time were 0.2 and 12 h, respectively. The subsequent epoxidation reaction resulted in an 89% yield and a β/α-epoxide ratio of 11.4/1.
TABLE 2 Stereoselective epoxidation of 3α-substituted Δ 5 -steroids by dioxiranes generated in situ a catalyst reaction loading time yield β/α-epoxide entry ketone substrate (equivalent) (h) b (%) c ratio d,e 1 1 f 11 20 2 90 19:1 2 2 11 0.05 2 93 5:1 3 3 11 0.1 3.5 91 4:1 4 4 11 0.2 8 92 90:1 5 2 12 0.05 4 82 72:1(2:1) 6 4 12 0.3 18 84 g >99:1 7 1 e 13 20 1 86 >99:1 8 2 13 0.05 2 94 96:1 9 3 13 0.1 1.5 93 49:1 10 4 13 0.3 12 84 >99:1 11 2 14 0.05 3.5 95 >99:1 12 4 14 0.3 18 86 h >99:1 13 2 15 0.05 2 88 79:1 (1:1) 14 4 15 0.2 10 83 86:1 15 2 16 0.05 3 95 91:1 16 4 16 0.2 12 82 >99:1 17 2 17 0.05 1 91 84:1 (1:1) 18 4 17 0.2 15 81 66:1 19 2 18 0.05 3.5 96 92:1 20 4 18 0.2 12 84 61:1 21 2 19 0.05 2 92 51:1 22 4 19 0.2 9 91 50:1 23 2 20 0.05 2 92 85:1(1:1) 24 4 20 0.3 12 82 62:1
[0191] [0191] TABLE 3 Stereoselective epoxidation of 3α-substituted Δ 5 -steroids catalyzed by acctonc. catalyst loading reaction time yield β/α-epoxide Entry substrate (equivalent) (h) b (%) c ratio d,e 1 11 20 5 90 3:1 (1:9.5) 2 13 20 5 94 >99:1 [f] (1:1) 3 14 20 6 93 >99:1 (1:1) 4 16 20 3.5 93 >99:1 (1:1) 5 18 20 6 92 >99:1 (1:1) 6 19 20 5 91 43:1 (1:1) | A general, efficient, and environmentally friendly method is provided for producing mostly β-epoxides of Δ 5 -unsaturated steroids using certain ketones as the catalyst along with an oxidizing agent, or by using certain dioxiranes. In another aspect of the invention, a method is provided for producing mostly 5β,6β-epoxides of steroids from Δ 5 -unsaturated steroids having a substituent at the 3α-position by an epoxidation reaction using a ketone along with an oxidizing agent under conditions effective to generate epoxides, or using a dioxirane under conditions effective to generate epoxides. A whole range of Δ 5 -unsaturated steroids, bearing different functional groups such as hydroxy, carbonyl, acetyl or ketal group as well as different side chains, were conveniently converted to the corresponding synthetically and biologically interesting 5β,6β-epoxides with excellent β-selectivities and high yields. | 2 |
FIELD OF INVENTION
This invention relates to a skid steer loader vehicle hereinafter referred to as "of the kind specified" comprising a body having a front end and a rear end and provided with first and second ground engageable propulsion means respectively disposed on opposite sides of the vehicle and in which the first and second propulsion means are driven by first and second transmission means respectively to permit the vehicle to be propelled and steered by driving the propulsion means on one side of the vehicle, independently from the propulsion means on the other side of the vehicle an operator's compartment and a boom assembly, the boom assembly having, at an outer end thereof, connecting means for connecting a material handling implement to the boom assembly and an inner end of the boom assembly being pivotally mounted on the body, adjacent the rear end of the body, for movement between a raised position and a lowered position in which the boom assembly extends forwards alongside the operator's compartment and the material handling implement is disposed forward of the front end of the body.
DESCRIPTION OF THE PRIOR ART
A skid steer loader vehicle of the kind specified is disclosed in U.S. Pat. No. 4,055,262. That vehicle has a single transmission case means in which the first and second transmission means are disposed and which requires the operator to straddle the transmission case means when the operator is seated in the vehicle.
In addition the boom assembly comprises two spaced lift arm assemblies disposed on opposite side of the vehicle with a material handling implement extending there between forward of the front of the vehicle when in a lowered position. Access to an operator's compartment is gained through the front of the compartment by negotiating the implement.
EP 0,443,830B also discloses a skid steer loader vehicle of the kind specified. In that vehicle there are two transversely spaced transmission case means, each containing a single transmission means and disposed apart on opposite sides of the vehicle between which the operator is disposed. In addition the vehicle has a single lift arm assembly which extends forwardly along one side only of the operator's compartment. In such a vehicle although the front access of U.S. Pat. No. 4,055,262 is avoided, since it is possible for the operator to gain access to the operator's compartment from the side of the vehicle, it is necessary for the operator to negotiate one of the transmission case means. In addition visibility to the rear is partly impeded by the presence of a pivot member for the lift aim assembly which extends transversely across the rear of the body so as to be pivotally mounted on the body at the opposite sides thereof.
SUMMARY OF INVENTION
An object of the invention is to provide a skid steer loader vehicle of the kind specified whereby the above mentioned problems are overcome or are reduced.
According to the invention we provide a skid steer loader vehicle of the kind specified comprising a transmission case means, disposed on one side of the vehicle, having therein said first and second transmission means.
The first transmission means may comprise a first drive member projecting from one side of the transmission case means and drivingly connected to the first ground engageable propulsion means and the second transmission means comprises a second drive member projecting from the opposite side of the transmission case means and extending transversely across the vehicle so as to be drivingly connected to the second ground engageable propulsion means.
The first transmission means may comprise a front first drive member and rear first drive member each projecting from one side of the transmission case means and drivingly connected to the first ground engageable propulsion means and the second transmission means comprising a front first drive member and a rear second drive member projecting from the opposite side of the transmission case means and extending transversely across the vehicle and drivingly connected to the second ground engageable propulsion means.
Each drive member may be drivingly connected to a respective driven wheel which is driven from a drive element, preferably by a drive loop.
The transmission case means may comprise a pair of spaced, preferably parallel, side walls between which said first and second transmission means are disposed.
The side walls may be joined by top and bottom walls and by opposite end walls.
The side walls may be provided with extension parts which comprise side walls of an upright disposed on said one side of the vehicle and providing, in an upward region thereof, a pivotal mounting means for a boom assembly comprising a single lift aim assembly which extends forwardly along one side only of the operator's compartment when in said lowered position.
Each ground engageable propulsion means may comprise two ground engageable wheels or an endless track entrained around a pair of guide wheels.
The ground engageable propulsion means, when comprising ground engageable wheels may be arranged so that each ground engageable propulsion wheel of the first ground engageable propulsion means is carried at an outer end of a stub axle which is housed, so as to be rotatable about an axis of rotation, in a stub axle housing member mounted on the body, said stub axle providing, or being drivingly connected, to a said drive member of the first transmission means.
Each second ground engageable propulsion wheel of the second ground engageable propulsion means may be carried at an outer end of an elongate axle which is housed, so as to be rotatable about an axis of rotation, in an elongate axle housing member mounted on the body.
The stub axle housing member may be mounted on said one wall of the transmission case means.
The elongate axle housing may be mounted in an aperture of said opposite wall of the transmission case means adjacent one end and in an aperture or other mounting arrangement provided on an opposite side of the body.
The body may be provided at said one side with said transmission case means and on the opposite side of the body with an opposite side wall which may have therein a downwardly extending recess between the front and rear second drive members to provide access to a region of the body disposed between said opposite sides.
The transmission case means and the opposite side walls of the body may be interconnected by front and rear transversely extending parts of the body. The rear transversely extending part may be disposed forwardly of the rear of the body to provide an engine compartment between side portions of the body adjacent the rear thereof.
Said rear transversely extending part may be disposed in front of said rear drive members.
The or each drive loop may comprise a chain such as roller chain and the drive elements and driven wheels may comprise sprockets for engagement with the chain.
Alternatively, the or each drive loop may comprise a toothed or untouched belt and the drive elements and driven wheels comprise cooperating pulleys.
The drive element may be carried on an output shaft of a motor, or a shaft driven by an output shaft of a motor.
Each motor may be mounted on the same side of the transmission case means as each other.
Each motor may be mounted on the outer or, preferably, the inner wall of the transmission case means so as to be disposed outwardly of the case means with the drive element disposed within the transmission case means.
A vehicle embodying the present invention thus provides easy access to the operators compartment from said other side of the vehicle without requiring the operator to negotiate a transmission case means. The vehicle is provided with improved structural integrity by providing the single tower as described hereinbefore as an extension of the transmission case means allows the input from the loader to be transmitted to the transmission car. In addition the single tower upright provides improved visibility to the rear of the vehicle by virtue of avoiding a pivot member which extends transversely across the rear of the vehicle.
The provision of each motor on the same inner wall of the transmission case means has the advantages of improved protection, a minimised wheel base is possible as there is no intrusion between the tyres of the wheels, servicing is easier and hose runs are easier.
DESCRIPTION OF THE DRAWINGS
An example of the invention will now be described with reference to the accompanying drawings wherein
FIG. 1 is a perspective view of a skid steer loader vehicle embodying the invention,
FIG. 2 is a side elevation of the vehicle of FIG. 1,
FIG. 3 is a plan view of the vehicle of FIG. 1 but with parts omitted for clarity.
FIG. 4 is a perspective view of a body part of the vehicle of FIG. 1 but with parts omitted for clarity,
FIG. 5 is a section on the line 55 of FIG. 4,
FIG. 6 is a perspective view similar to that of FIG. 4 but taken from the opposite side of the vehicle body, and
FIG. 7 is a fragmentary section on the line 77 of FIG. 3 with parts omitted for clarity.
Referring now to the drawings a skid steer loader vehicle 10 comprises a body 11 having a front end 12 and a rear end 13.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The body 11 is provided with first ground engageable propulsion means 14 comprising a front ground engageable wheel 15 and a rear ground engageable wheel 16 and, on the opposite side of the body, a second ground engageable propulsion means 17 similarly comprising a rear wheel 18 and a front wheel 19. The vehicle 10 may be propelled in a straight line forwardly or rearwardly by driving all four wheels at the same speed, or, to steer the vehicle, by driving the wheels 15, 16 of the first ground engageable propulsion means 14 at a different speed and/or direction than the wheels 17, 18 of the second ground engageable means 19. Such skid steer loaders have a high degree of manoeuvrability and to facilitate skid steering and in particular, for example, the ability of the vehicle to turn about a central axis of the ground engageable propulsion means the wheel base is made, in the present example, slightly shorter than the track of the vehicle although, if desired, the wheel base may be the same or longer than the track if desired.
The wheels 15, 16 are carried on hubs 20, non-rotatably fixed to stub axles 21 which are rotatably carried in stub axle housing members 22 by bearings 22a and provide first drive members.
The wheels 18, 19 are carried on hubs 23, non-rotatably fixed to elongate axles 24 which are rotatably mounted in elongate tubular axle housings 25 by bearings 25a and provide second drive members.
Referring now particularly to FIGS. 4 to 6, the body 11 comprises, at one side, a single transmission case means 30 comprising a generally planar outer side wall 31 and a generally planar inner side wall 32. The side walls 31, 32 are connected together by a bottom wall 33 and an inclined top wall member 34 which is connected at its outer end to the outer wall 31 and at its inner upper end is connected to an inwardly and upwardly inclined further part 35 integral with of the inner wall 32. In this example the side walls are generally parallel but if desired they may not be.
An extension part 36 is integral with the further part 35 and projects upwardly and is provided with an inwardly directed flange 37 which provides a mounting 37a, for a rear member of a side frame 38 of an operator's compartment 39. A front member of the side frame 38 and a front member of an opposite side frame 40 of the operators compartment are fastened at 37b and at 40a respectively to an inturned flange 41 of a front wall part 42 of the body which extends transversely across the body at the forward end 12 thereof.
A rear member of the frame 40 is mounted on a second transversely extending wall 50.
The frames 38 and 40 are provided with a top wall 46 and may be glazed and/or provided with other parts in conventional manner as desired.
The front wall part 42 is connected to an opposite side wall 43 of the body which is provided with a cut out part 44 to provide access to an internal cavity 45 of the body in which an operator's seat and conventional controls for driving and operation of the lift arm assembly are provided.
The second transversely extending wall 50, is provided between the inner side wall 32 of the transmission case means 30 and the further and extension parts 35, 36 on the one side of the body and the opposite side wall 43 at a position disposed intermediate the front and rear ends 12,13 of the body. It provides a bulk head between the operator's compartment 39 and the engine of the vehicle. The inner side wall 32 of the transmission case means and the further and extension parts 35, 36 extend rearwardly of the transverse wall 50 and together with an extension part 51 of the side wall 43, provide an engine compartment 53 behind the operator's compartment. The extension part 51 is parallel to the side wall 43 but is spaced outwardly thereof by a transversely extending wall 52 which provides a wheel arch 53. A front wheel arch 54 is provided by a further intermediate wall 55. The walls 52 and 55 are secured to the side wall 43 by screw threaded fasteners.
An extension part 60 of the outer side wall 31 of the transmission case means 30 provides one, outer member of an upright or tower 61 whilst an extension part 62 of the inner wall 32 provides an inner side wall of the tower 61. The extension part 60 is parallel to the outer side wall 31 but is spaced outwardly thereof by an inclined part 60a which is integral with the wall 31 and the extension part 60. The tower 61 is reinforced by a transversely extending member 63 and is further reinforced by members 64 and 65. Provided adjacent an upper end of the tower 61 is a pair of mounting bushes 66 by which a single lift arm assembly 67 is pivotally mounted, at its inner end, to the body 10 adjacent the rear end 13 thereof The lift arm assembly 67 is disposed adjacent one side 68 of the operator's compartment 39. The lift arm assembly 67 has receiving means, not shown, for a pivot pin 70, which is received therein and in said bushes 66 to provide a pivot for the lift arm assembly 67.
At its forward end the lift aim assembly 67 has an implement carrying member 71 which projects from a outer or front end 72 of the lift arm assembly 67 and extends transversely across the front end of the body 12 forwardly thereof and has a material handling implement 73 carried thereby so as to be disposed forward of the front end 12 of the body 11. In the present example, the implement 73 is an earth moving bucket although, if desired, other material handling implements may be provided such as a set of forks.
The lift aim assembly 67 is formed as a generally square section tubular fabrication and comprises a major part 74 which extends generally rectilinearly from the inner end 69a of the lift arm assembly towards the outer end 72 and a minor part 74a which extends generally downwardly and forwardly relative to the main part 74 to terminate at the outer end 72 and provided with the implement carrying means 71.
A hydraulic lift ram 75 is pivotally connected between a reinforced part 76 of the outer wall 31 of the transmission case means 30, where it merges with the outer wall 60 fo the tower, and a bracket 77 welded to the lift aim assembly 67 in the region of the junction between the pairs 74 and 75. The pivotal connection of the lift ram 75 at each end comprises a pivot pin 78 which is mounted in pivot bushes welded in openings provided in the respective plates and bracket and extending through apertures provided in the ram at opposite ends thereof. In addition a crowd ram 80 is provided between a pivot pin 81 disposed in cantilever on the lift arm assembly 69 and pivot pin mounting apertures 81a of the implement carrier 71.
Referring now to FIGS. 3 and 7, the transmission case means 30 has therein first and second transmission means T1, T2 by which the first and second propulsion means 14, 17 are driven. Each drive member 21 is provided with first, front and rear, driven wheels 90, 91 respectively, rigidly connected thereto. The driven wheels 90, 91 are connected, by drive loops 92, 93 respectively, to respective drive elements 94, 95 carried on an output shaft of a first hydro-static drive motor 96.
The drive members 24 are similarly provided with second, front and rear, driven wheels 97, 98 connected by respective drive loops 99, 100 to respective drive elements 101, 102 carried on an output shaft of a second hydro-static drive motor 103 disposed below the motor 96. Of course, if desired, the motor 103 may be disposed above the motor 96.
If desired, the drive elements 94, 95, 101, 102 may be provided on a shaft separate from the motor output shaft but driven thereby.
The first transmission means T1 comprises the first drive member 21, drive wheels 90, 91, drive loops 92,93 and drive elements 94, 95. The second transmission means T2 comprises the second drive members 24, drive wheels 97, 98, drive loops 99, 100 and drive element 101, 102.
In the present example, the driven wheels and drive elements comprise sprockets around which drive loops comprises roller chains are entrained. If desired, however, the drive loops may comprise other means such as toothed or untoothed belts in which case means they would be entrained around suitably configured co-operating drive elements and driven wheels.
The stub axle housings 22 are arranged so that each is bolted to the casing 30 so that it may be rotated and the axis of rotation of the stub shaft being eccentric to the axis of rotation of the housing in a manner similar to that described in EP 0,443,830 so that the tension of the loops 92, 93 may be adjusted.
The tension of the loops 99, 100 is adjusted by moving the drive motor 103 associated therewith vertically up and down relative to the inner member 32 of the loop case means.
If desired, instead of each ground engageable propulsion means comprising two ground engageable wheels each ground engageable propulsion means may comprise an endless track engaged around a pair of guide wheels. At least one of the guide wheels may be carried by hubs 20 or 23 or members similar thereto and have an endless track entrained there around. In this case means, if desired, only one of the guide means may be driven by a guide wheel 90, 91 or 97, 98 from the associated drive element 94, 95 or 101, 102.
Further alternatively, in either case if desired the drive members 21, 24 may be driven by means other than drive loops, for example, by gears or a combination of gears and drive shafts from an associated motor.
An engine, indicated generally at E in FIG. 3 is provided in the engine compartment 50 in conventional manner and connected to one or more hydraulic pumps which are operable by the control means to drive the motors 96, 103 described hereinbefore in conventional manner.
In the above described example the components of the vehicle are conventionally joined together by welding, but if desired, may be joined together by other means such as fasteners. Where components have been described hereinbefore as being integral with each other they may, if desired, be made from discrete elements which are joined together by welding or in any other suitable manner.
Although in the above described example the lift arm assembly and the transmission case means have been described as being provided on the right hand side of the vehicle when facing towards the front of the vehicle, if desired, the configuration of the vehicle may be reversed so that the lift arm assembly and the transmission case means are provided on the left hand side of the vehicle when facing forwardly and a cut out, corresponding to the cut out 44, provided on the right hand side of the vehicle.
The transmission case means described hereinbefore has comprised a single transmission case having only two spaced parallel side walls between which the first and second transmission means are disposed. However, if desired, the transmission case means may comprise two separate transmission cases each having a pair of spaced preferably parallel side walls between each pair of which only one of said transmission means is disposed. The separate transmission cases may be constructed as desired and may be integral with each other or connected together as desired. Further alternatively the transmission case means may comprise two spaced preferably parallel side walls with an intermediate wall disposed there between to form two separate compartments in each of which one of said first or second transmission means is disposed. If desired other configuration of transmission case means may be provided.
The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, or a class or group of substances or compositions, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof. | A skid steer loader vehicle comprising a body having a front end and a rear end and provided with first and second ground engageable propulsion wheels respectively disposed on opposite sides of the vehicle and in which the first and second propulsion wheels are driven by first and second transmission systems respectively to permit the vehicle to be propelled and steered by driving the propulsion wheels on one side of the vehicle independently from the propulsion wheels on the other side of the vehicle, an operator's compartment and a boom assembly, the boom assembly having, at an outer end thereof, connecting structure for connecting a material handling implement to the boom assembly and an inner end of the boom assembly being pivotally mounted on the body, adjacent the rear end of the body, for movement between a raised position and a lowered position in which the boom assembly extends forwards alongside the operator's compartment and the material handling implement is disposed forward of the front end of the body and a transmission case, disposed on one side of the vehicle, having therein said first and second transmission systems. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
The present invention is directed generally to cleaning a surface and, more particularly, to cleaning the surface of a semiconductor substrate following a chemical, mechanical, or chemical mechanical polishing of the substrate surface.
Integrated circuits are typically constructed by depositing layers of various materials to form circuit components on a wafer shaped semiconductor substrate. The formation of the circuit components in each layer generally produces a rough, or nonplanar, topography on the surface of the wafer. A rough surface on an underlying layer increases the likelihood of a defect occurring in subsequently deposited layers that can result in flawed or improperly performing circuitry. Thus, the efficient production of integrated circuits depends, in part, on the ability to produce smooth, or planarized, surfaces on which subsequent circuitry can be precisely deposited.
A smooth surface on the layers is generally provided by performing a planarization process. There are numerous processes used to planarize a surface, which are generally classified in the art as chemical planarization (such as etching), mechanical planarizing, and/or chemical-mechanical planarizing.
While each of the planarization processes generally provides for a more smooth surface, residual chemicals and/or particles may remain on the surface following the process. The residual chemicals and particles also must be removed to prevent defect formation in subsequent layers. Such defects may result either physically from the presence of particles or chemically via the interaction of the residual chemicals or particles with the composition of the subsequently deposited layer.
Post-planarization cleaning of the surface is often performed using various methods depending upon the composition of the layer and any residual chemicals and particles that may be present on the layer. The cleaning methods are generally wet cleaning procedures that include chemical cleaning, mechanical scrubbing and other surface agitation techniques.
For example, some cleaning methods are purely chemical or mechanical, such as those described in U.S. Pat. No. 5,181,985 and Japanese Patent Abstract Publication No. 02-281,733, respectively. As might be expected, these methods are generally more suitable for the removal of either residual chemicals or particles, respectively. Other methods, such as those described in U.S. Pat. Nos. 5,475,889, 5,442,828, 5,529,638, and 5,555,177 employ mechanical brush scrubbers that are used to brush particles from the surface, while liquid jet sprays are used to wet the surface, and possibly dislodge particles, with deionized water and/or cleaning solutions. While many of these methods provide both chemical and mechanical cleaning of the surfaces, the cleaning results derived from the methods are subject to variation due to uneven chemical distribution on the surface of the substrate which contributes to varying mechanical cleaning effectiveness and the potential for uneven drying of the surface subsequent to cleaning.
Still other methods rely on other forms of agitation to remove the residual chemicals or particles. For example, U.S. Pat. No. 5,451,267 discloses an apparatus in which a cleaning solution is agitated by bubbling a gas through the cleaning vessel to produce liquid flow past the surface to be cleaned. U.S. Pat. Nos. 3,893,869, 4,804,007, 4,869,278, 4,998,549, 5,037,481, 5,365,960, 5,368,054, 5,427,622, 5,533,540, and 5,534,076 disclose cleaning systems in which cleaning solutions and surfaces are acoustically agitated. The efficiency of these agitation methods depends upon the effectiveness of the flowing liquid or the acoustic energy at dislodging particles from the surface. It is expected that the effectiveness of the methods will depend upon the composition of the particle and the layer, as well as the particle sizes and surface affinity. It is therefore difficult to provide an effective cleaning procedure given the expected variations in residual chemicals and particle distributions during production processing of semiconductor substrates.
Following wet cleaning procedures, as the fluid on the surface of the substrate evaporates, particles and other contaminants contained in the residual cleaning fluid may settle on the surface to form water marks. Therefore, it is desirable to dry the surface following a wet cleaning procedure in a manner that minimizes evaporation and the resulting formation of water marks. A number of methods, such as those described in U.S. Pat. Nos. 5,660,642, 5,569,330, 5,653,045, 5,634,978, 5,601,655, and 5,571,337, utilize the formation of a Marangoni flow to decrease the surface tension of fluid on the surface, thereby facilitating the removal of the water from the surface prior to evaporation.
As is evident from the aforementioned discussion, a number of difficulties remain with present cleaning methods that need to be overcome to provide an effective cleaning method for surfaces. The present invention serves to provide methods and apparatuses for cleaning surfaces, in particular, the surfaces of semiconductor substrate layers.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to surface cleaning and drying methods and apparatuses that provide for improved cleanliness of surfaces. The apparatus generally includes a chamber suitable for retaining cleaning fluids and receiving at least one substrate having a surface that is to be cleaned. The chamber preferably includes mechanical scrubbers, generally in the form of cylindrical brushes or pads, submerged in the cleaning fluids within the chamber and positioned to contact and scrub at least one substrate submerged in the cleaning fluid. In a preferred embodiment, the substrates are fully submerged during the scrubbing, although the portion not being contacted by the scrubber need not be submerged. The chamber may further include at least one discharge for spraying a fluid, such as deionized water, onto the substrate to rinse the residual cleaning fluid from the substrate. In a preferred embodiment, the discharge is located within the same chamber as the mechanical scrubbers. The chamber may further include a mechanism for drying the substrate once the cleaning and rinsing processes have been completed. In a preferred embodiment, the drying mechanism utilizes the formation of a Marangoni flow to remove fluid from the surface of the substrate before it evaporates. Also in a preferred embodiment, the drying apparatus is included in the same chamber as the scrubbing apparatus, although in alternative embodiments, separate chambers may be used for one or more of the individual scrubbing, rinsing, and drying apparatus.
The apparatus also preferably includes a cleaning fluid recirculation loop that is used to remove residual chemicals, particles, and other contaminants from the cleaning fluid and to replenish the cleaning fluid. In this manner, the substrate surfaces can be more uniformly contacted by chemical cleaning fluids and the composition of the cleaning fluid can be more precisely controlled. In the embodiment in which the cleaning, rinsing, and drying processes are performed within the same chamber, the recirculation loop is additionally used to drain the cleaning and rinsing fluids from the chamber so that the rinsing and drying process may be initiated.
An embodiment of the mechanical scrubbing apparatus may additionally include megasonic enhancement to the mechanical scrubbing process. Megasonic cleaning is known in the art and involves generating a megasonic signal (0.2-5 MHz) within the bath of cleaning fluid and directing it substantially parallel to the submerged surface of the substrate to be cleaned. The megasonic signal causes the cleaning fluid through which the signal passes to become agitated. The action of the fluid agitation against the surface of the substrate causes minute particles to become dislodged from the substrate. Such particles are generally tenaciously adhered to the substrate and would not otherwise be readily dislodged by mechanical scrubbing methods without an increased potential for damage to the substrate caused by increased direct contact to the surface of the substrate brought on by additional brushing or scrubbing. Mechanical scrubbing with megasonic enhancement thus provides a benefit over purely mechanical methods of brushing or scrubbing in that it serves to remove additional particulate matter from the surface of the substrate without contacting the substrate. As such, the potential for damage to the substrate from additional brushing or scrubbing is also removed.
In an embodiment of the drying method, the cleaning fluid preferentially produces a surface composition that is hydrophilic. The formation of such a hydrophilic surface thus aides in the evacuation of fluid from the surface of the substrate, thereby reducing the potential for deposition of contaminants at the interface of hydrophilic and hydrophobic portions of the surface. In a further aspect of the drying method, after the cleaning process, the surface of the substrate is flushed with a rinsing fluid to remove the cleaning fluid from the surface of the substrate. However, after the rinse a thin film of fluid often remains on the surface of the substrate. If the film is allowed to evaporate on the surface of the substrate, impurities held by the fluid will be deposited on the surface of the substrate. Drying methods such as gravity flow and spin drying, are thus used to evacuate the fluid from the surface of the substrate before it is allowed to evaporate. However, such methods alone have proven ineffective in removing sufficient quantities of fluid from the surface of the substrate prior to evaporation. The present invention thus calls for the formation of a surface tension gradient, or Marangoni gradient, on the surface of the substrate to enable the rapid removal of the film of fluid remaining from the surface of the substrate. Such a Marangoni drying process is achieved by the passive introduction (by natural evaporation and diffusion of vapors) of surface tension-reducing volatile organic compounds, in the vicinity of the film of fluid adhering to the surface of the substrate. The compounds will diffuse into the film of fluid, resulting in surface tension gradients (Marangoni gradients) and causing the surface tension of the film of fluid to decrease. After reducing the surface tension, the film of fluid can then be more easily removed from the surface of the substrate by way of gravity flow, spin drying, or other removal techniques as are known in the art. Marangoni drying thus has the benefit of expediting the removal of the film of water from the surface of the substrate while avoiding the potentially deleterious effects brought on by using heat, air flow, or direct physical contact to dry the surface of the substrate. Marangoni drying also has the additional benefit of inducing the film of water to leave the surface of the substrate without allowing it to evaporate while on the surface of the substrate and deposit any impurities contained therein on the surface of the substrate.
Accordingly, the present invention overcomes the aforementioned problems to provide apparatuses and methods that provide for improved cleanliness of surfaces, such as semiconductor wafer substrates. These advantages and others will become apparent from the following detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying Figures wherein like members bear like reference numerals and wherein:
FIG. 1 is a semi-schematic view of an embodiment of the apparatus of the present invention;
FIG. 2 is a cut-away view of the wafer conveyor of the embodiment shown in FIG. 1;
FIG. 3 is a cut-away side view of the wafer conveyor of the embodiment of FIG. 1;
FIG. 4 is a side view of the roller of the embodiment of FIG. 1; and
FIG. 5 is a semi-schematic view of another embodiment of the apparatus of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The operation of the submerged cleaning apparatus 1 will be described generally with reference to the drawings for the purpose of illustrating the present preferred embodiments of the invention only and not for purposes of limiting the same. Referring now to the drawings, the figures show a submerged cleaning apparatus for mechanically cleaning semiconductor substrates. More particularly, and with reference to FIG. 1, the submerged scrubber is shown generally as 1 . The preferred construction of the submerged cleaning apparatus 1 of the present invention, as shown in FIG. 1, includes a submersion chamber 10 and a drying chamber 30 . Preferably, a recirculation system 40 and a loading area 50 are also provided.
In the present embodiment, the drying chamber 30 , is preferably located adjacent to and above the submersion chamber 10 . The submersion and drying chambers 10 and 30 , respectively, are separated by a wall 32 . The wall 32 thus forms the ceiling of the submersion chamber 10 and the floor of the drying chamber 30 and thereby serves to prevent communication of fluid 4 between the submersion chamber 10 to the drying chamber 30 . Wafers 3 to be cleaned enter the apparatus on wafer trays 2 at a loading area 50 , located on the side of the apparatus 1 at the lower end of the submersion chamber 10 . Upon entering the loading area 50 , the door 52 to the loading area 50 is closed and the seal 13 separating the loading area 50 from the submersion chamber 10 is opened. As such, the wafers 3 are submerged in the bath of cleaning fluid 4 . The wafers 3 move into the submersion chamber 10 on wafer tray conveyor 14 . Upon entering the submersion chamber 10 , the individual wafers 3 are transferred by suitable handling apparatus from the wafer tray 2 to a wafer conveyor 15 which carries the individual wafers 3 through a series of submerged mechanical and megasonic cleaning apparatus 26 and 28 ; respectively. After leaving the bath of cleaning fluid 4 , the wafers 3 enter a drying chamber 30 and are transferred back to a wafer tray 2 . After drying operations in the drying chamber 30 , wafers 3 exit the apparatus 1 at a door 52 located on the side of the drying chamber 30 at the upper end of the apparatus 1 .
The submersion chamber 10 provides a contained environment suitable for holding a bath of chemical cleaning fluid 4 therein. The composition of the bath of chemical cleaning fluid 4 is dependent upon the surface to be cleaned and the contaminants to be removed. However, one preferred chemistry is dilute TMAH. The submersion chamber 10 is preferably constructed as a tank that is impervious to the chemicals contained in the bath of cleaning fluid 4 . Preferably, the submersion chamber 10 is constructed from polytetrafluoroethylene (PTFE). A wafer tray conveyor 14 is positioned within the chamber 10 along the floor for moving wafer trays 2 containing wafers 3 from the loading area 50 into the submersion chamber 10 . Adjacent to the conveyor 14 , a set of opposing parallel rail members 16 and 18 define the path of wafer conveyor 15 . Preferably, wafer conveyor 15 is oriented perpendicular to the tray conveyor 14 and is positioned such that individual wafers 3 may be drawn directly from the wafer tray 2 into the wafer conveyor 15 .
As shown in particular in FIGS. 2 and 3, the wafer conveyor 15 includes two generally parallel rail members 16 and 18 that run along the length of the submersion container 10 . Each rail member 16 and 18 , has a set of rollers 17 and 19 , respectively, mounted thereon. The rail members 16 and 18 are preferably U-shaped in cross-section. However, it will be appreciated that additional cross-sectional configurations resembling, for example “C” or “V” are also suitable for the design of the rail members 16 and 18 . The opposing sets of rollers 17 and 19 are rotatably connected along the length of the inner edge of each of the rail members 16 and 18 , respectively. As shown in particular in FIG. 4, each of the rollers 22 and 19 preferably has a notch 17 therein. The notch 22 in each of the rollers 17 and 19 preferably has oppositely angled walls 23 and 24 such that the notch 22 is widest around the circumference of each roller 17 and 19 and tapers toward the center axis of each roller 17 and 19 . In operation, the two opposing sets of rollers 17 and 19 are preferably spaced from each other by a distance that is less than the diameter of one wafer 3 . Thus, as shown in particular in FIG. 3, wafers 3 are held between the opposing sets of rollers 17 and 19 , with minimal contact to the surface of the wafer 3 by the walls of the notch 23 and 24 . When the sets of rollers 17 and 19 are driven by a motor (not shown), the wafers 3 held therebetween will be transported along the length of the wafer conveyor 15 . It will further be appreciated that in additional embodiments, alternative designs such as motorized belts (not pictured) or individual wafer trays (not pictured) could also be used to hold the individual wafers 3 within the wafer conveyor 15 .
Mechanical brush scrubbers 26 are positioned to contact both surfaces of the wafer 3 as it is moved along the length of the wafer conveyor 15 . Such brushes 26 are well known in the art and are manufactured and sold, for example, by Syntak, Incorporated. The brushes 26 are typically cylindrical and have surfaces (not shown) populated with a plurality of protrusions. The geometry of the protrusions may be that of circular knobs, linear ridges, or any other pattern known in the art. In operation, when the cylindrical brush 26 is rotated, the protrusions physically contact the surface of the wafer 3 and work to remove impurities deposited thereon. Preferably, the cylindrical brushes 26 are positioned on either side of the wafer conveyor 15 such that both sides of the wafer 3 may be cleaned simultaneously.
Preferably, the mechanical brush scrubbers 26 are augmented by megasonic cleaning apparatuses as are known in the art. The megasonic enhancement of the mechanical brushes 26 includes a series of transducers 28 positioned below the surface of the chemical bath 4 within the submersion chamber 10 . The transducers 28 are oriented relative to the surface of the wafers 3 held in the wafer conveyor 15 such that they direct a high frequency (megasonic) signal through the bath of cleaning fluid 4 substantially parallel to the surfaces of the submerged wafers 3 . Preferably, the frequency of the signal emitted by the transducers 28 will be made to vary between 0.2 and 5 MHz. In operation, the high frequency of the signal causes the fluid 4 through which the path of the signal passes to become agitated. In particular, the fluid 4 directly surrounding the surfaces of the wafers 3 is agitated. The action of the agitated fluid 4 against the surface of the wafer 3 serves to enhance the removal of minute particles from the surface of the wafer 3 , that would otherwise require additional mechanical brush scrubbers 26 to remove.
The drying chamber 30 is located above the submersion chamber 10 and may be separated therefrom by a wall 32 . As such, the wall 32 prevents the chemical bath 4 contained in the submersion chamber 10 from entering the drying chamber 30 . Preferably, the wall 32 contains gap 31 therein through which the wafer conveyor 15 passes from the submersion chamber 10 to the drying chamber 30 . The gap 31 thus enables the wall 32 to inhibit the interaction of the atmospheres of the two chambers 10 and 30 , while allowing the wafers 3 held within the wafer conveyor 15 to pass from the submersion chamber 10 into the drying chamber 30 . Within the drying chamber 30 , the wafer conveyor 15 meets a second wafer tray conveyor 56 . The conveyor 56 is designed to hold a wafer tray 2 thereon and to position the tray 2 such that wafers 3 may be transferred directly from the wafer conveyor 15 into the tray 2 . The drying chamber 30 further includes a series of spray nozzles 33 . The spray nozzles 33 are supplied with a rinsing fluid and are positioned to direct a stream of the rinsing fluid onto the surfaces of the wafers 3 to flush the surface of the wafers 3 and to remove any residual fluids remaining on the surface of the wafers 3 from the cleaning fluid 4 from the surface of the wafer 3 . Preferably, the composition of the rinsing fluid will include de-ionized water. The nozzles 33 are also supplied with surface tension reducing compounds and are equipped to flush the surface of the wafers 3 with the surface tension-reducing compounds to induce surface tension gradients (Marangoni gradients) between the surface of the wafer 3 and any fluid remaining on the surface of the wafer 3 after the rinse process has been completed. The resulting Marangoni flow is known in the art and is commonly used to remove fluid from surfaces prior to the evaporation of that fluid. In operation, a stream of fluid from the nozzles 33 is directed at the surfaces of the wafers 3 . The stream diffuses into any fluid remaining on the surface of the wafers 3 , resulting in a Marangoni gradient and causing the surface tension of the fluid already on the surfaces of the wafers 3 to decrease. The reduced surface tension of the fluid on the surfaces of the wafer 3 thus enables the fluid to be more easily removed from the surfaces of the wafers 3 by means of gravity flow, spin drying, or other like drying techniques known in the art. Preferably, the surface tension-reducing compound sprayed by the nozzles 33 onto the surfaces of the wafers 3 will include volatile organic compounds such as isopropyl alcohol. However, it will be understood that additional compounds having similar surface tension reducing properties such as ethanol may also be used.
The drying chamber 30 is preferably provided with a door 57 through which the wafer tray conveyor 56 travels. When the door 57 is closed, the environment within the drying chamber 30 is unable to communicate with the environment outside the chamber 30 . However, when the door 57 is opened, an empty wafer tray 2 may be inserted into the chamber 30 , or a wafer tray 2 with wafers 3 therein removed from the chamber 30 .
A loading chamber 50 is also preferably provided from which a wafer tray 2 containing wafers 3 to be cleaned may be inserted into the apparatus 1 . In operation, a wafer tray 2 containing wafers 3 is placed onto a wafer elevator 51 . The elevator 51 lowers the wafer tray 2 into the loading chamber 50 . Once within the loading chamber 50 , the door 52 of the loading chamber 50 is closed, sealing the loading chamber 50 from the outside atmosphere and the door 13 linking the loading chamber 50 and the submersion chamber 10 is opened allowing the inside of the loading chamber 50 to communicate with the inside of the submersion chamber 10 . The tray 2 is then moved on conveyor 14 to the submersion chamber 14 on conveyor 11 and positioned to load the wafers 3 contained thereon into the wafer conveyor 15 .
A recirculation system 40 is preferably provided for replenishing the volume of chemical cleaning fluid 4 in the submersion chamber 10 . Such a recirculation system 40 is known in the art and is capable of removing residual chemicals, particles, and other contaminants from the chemical cleaning fluid 4 and returning the cleaned fluid 4 to the submersion chamber 10 . The recirculation system 40 is also used to drain and fill the submersion chamber 10 and the loading chamber 50 with cleaning fluid 4 as is needed to facilitate the submerged cleaning process.
In a further embodiment of the present invention shown in FIG. 5, the submerged mechanical scrubbing and drying operations are conducted within a single container 9 . As such, the container 9 performs the function of the submersion chamber 10 and the drying chamber 30 described herein with regard to previous embodiments and like embodiments will be similarly numbered.
As seen in FIG. 5, the container 9 is adapted to hold a bath of cleaning fluid 4 therein and to remain impervious to the effects of the chemicals that make up the bath of cleaning fluid 4 for prolonged periods of time. A wafer conveyor 15 ′ is contained within the container 9 . The conveyor 15 ′ follows a generally U-shaped path through the container 9 . As such, the ends 59 and 60 of the conveyor 15 ′ are above the surface of the bath of cleaning fluid 4 , while the remainder of the conveyor 15 ′ remains submerged within the bath of cleaning fluid 4 . The general design and operation of the wafer conveyor 15 ′ is otherwise identical to that of other embodiments of the wafer conveyor 15 described herein above. As is the case with previous embodiments, scrubber brushes 26 are positioned beneath the surface of the bath of cleaning fluid 4 along the path of the conveyor 15 ′. The design and operation of the brushes 26 are otherwise identical to that of other embodiments of the brushes 26 described herein above. As such, the brushes 26 contact and clean the surface of the wafers 3 contained in the conveyor 15 ′. Adjacent to the brushes 26 lies a series of one or more transducers 28 . The transducers 28 are oriented to direct beams of megasonic energy parallel to the surfaces of the wafers 3 held within the wafer conveyor 15 ′ as the wafers pass the brushes 26 . The design and operation of the transducers 28 are otherwise equivalent to that of the transducers 28 described previously herein above. Adjacent to the portion of the conveyor 15 ′ lying after the brushes 26 and above the surface of the bath of cleaning fluid 4 are a series of spray nozzles 33 . The design and operation of the nozzles 33 are otherwise identical to those of other embodiments of the nozzles 33 described herein above.
Wafer tray conveyors 53 and 56 may also be provided for use in loading and unloading trays 2 of wafers 3 from the container 9 . Preferably, the loading conveyor 53 intersects one end 59 of the wafer conveyor 15 ′. When a tray 2 of wafers 3 is positioned on the conveyor 53 above the end 59 of the wafer conveyor 15 ′, the wafers 3 may be fed directly into the wafer conveyor 15 ′. Similarly, an unloading conveyor 56 intersects the end 60 of the wafer conveyor 15 ′. When a tray 2 of wafers 3 is positioned on the conveyor 56 above the end 60 of the wafer conveyor 15 ′, the wafers may be fed directly from the wafer conveyor 15 ′ into the wafer tray 2 . Thus, after being loaded into the container 9 at 59 , the wafer tray 2 may be advanced along the loading conveyor 53 , onto unloading conveyor 56 , and positioned above 60 to receive a load of cleaned wafers 3 being unloaded from container 9 .
The present embodiment of the invention also preferably includes a cleaning fluid 4 recirculation system 40 for recirculating and replenishing the cleaning fluid 4 in the container 9 as is needed to facilitate the cleaning process, the design and operation of which is identical to those embodiments described previously herein above. The design and operation of the recirculation system 40 is otherwise identical to that of the recirculation system 40 previously described herein with regard to other embodiments of the present invention.
In operation, a wafer tray 2 with wafers 3 therein is positioned on the loading conveyor 53 and moved to the end 59 of the wafer conveyor 15 ′. The wafers 3 are loaded from the wafer tray 2 onto the wafer conveyor 15 ′. The wafer conveyor 15 ′ transports the wafers 3 into the bath of cleaning fluid 4 . Beneath the surface of the bath of cleaning fluid 4 , the wafers 3 are moved along the wafer conveyor 15 ′ past a series of the rotating cylindrical brushes 26 . The surfaces of the wafers 3 are contacted and cleaned by the brushes 26 . In conjunction with the brushes 26 , transducers 28 direct megasonic signals parallel to the surfaces of the wafers 3 so as to create agitation in the fluid 4 along the surface of the wafers 3 and to remove impurities therefrom. After passing through the scrub brushes 26 and transducers 28 , the wafer conveyor 15 ′ emerges from the bath of cleaning solution 4 and passes a series of spray nozzles 33 . As with previous embodiments, the nozzles 33 first flush the surface of the wafers 3 with a rinsing solution to remove the residual chemical cleaning solution 4 from the surface of the wafers 3 . The nozzles 33 then spray the surface of the wafers 3 with a surface tension-reducing compound to induce a Marangoni flow on the surface of the wafers 3 to dry the surfaces of the wafers 3 of any residual fluid or chemicals before those chemicals are allowed to evaporate on the surface of the wafer 3 . The wafers 3 are then unloaded directly into a waiting wafer tray 2 sitting atop the unloading conveyor 56 at end 60 of the wafer conveyor 15 ′.
Those of ordinary skill in the art will appreciate that a number of modifications and variations that can be made to specific aspects of the method and apparatus of the present invention without departing from the scope of the present invention. Such modifications and variations are intended to be covered by the foregoing specification and the following claims. | Apparatuses and methods are disclosed for submerged cleaning of substrates and the like. The apparatus includes a container holding a bath of cleaning fluid and, within the container, the combination of a submerged brush scrubber, submerged megasonic transducer and Marangoni drying devices. In operation, at least a portion of a substrate is submerged in the bath of cleaning fluid where its surfaces are contacted by one or more brush scrubbers while beams produced by megasonic transducers are directed parallel to the surface of the substrate along the surface of the substrate. The substrate is removed from the bath of cleaning fluid and rinsed with rinse water. A Marangoni flow is induced on the surface of the substrate and the substrate is allowed to dry through one or more means of drying, thereby rendering the substrate free from particulate contamination and dried of any residual fluid from the cleaning process. | 8 |
RELATED APPLICATIONS
This application is a national phase application of PCT Application PCT/US2007/004193, filed Feb. 15, 2007, and published in English on Aug. 30, 2007, as International Publication No. WO 2007/098053, and which claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application Ser. No. 60/774,442, filed Feb. 17, 2006, U.S. Provisional Patent Application Ser. No. 60/774,587, filed Feb. 17, 2006, and U.S. Provisional Patent Application Ser. No. 60/774,920, filed Feb. 17, 2006, the disclosures of each of which is incorporated herein by reference in its entirety.
This application is related to: Mark E. Van Dyke, U.S. patent application Ser. No. 11/205,800, titled: Ambient Stored Blood Plasma Expanders, filed Aug. 17, 2005, and published on Mar. 9, 2006, as 2006/0051732; Mark E. Van Dyke, U.S. patent application Ser. No. 11/673,212, titled: Nerve Regeneration Employing Keratin Biomaterials, filed Feb. 9, 2007, and published on Dec. 27, 2007, as 2007/0298070; and Mark E. Van Dyke, U.S. patent application Ser. No. 11/676,072, and PCT Application (published Aug. 30, 2007 as W02007/098114), titled: Clotting and Healing Compositions Containing Keratin Biomaterials, filed Feb. 16, 2007.
GOVERNMENT SUPPORT
This invention was made with Government support under contract number W81XWH-04-1-0105 from the United States Army. The U.S. Government has certain rights to this invention.
FIELD OF THE INVENTION
The present invention is generally related to keratin biomaterials and the use thereof in biomedical applications.
BACKGROUND OF THE INVENTION
The earliest documented use of keratin in medicine comes from a Chinese herbalist named Li Shi-Zhen (Ben Cao Gang Mu. Materia Medica, a dictionary of Chinese herbs, written by Li Shi Zhen (1518-1593)). Over a 38-year period, he wrote a collection of 800 books known as the Ben Cao Gang Mu . These books were published in 1596, three years after his death. Among the more than 11,000 prescriptions described in these volumes, is a substance known as Xue Yu Tan, also known as Crinis Carbonisatus, that is made up of ground ash from pyrolized human hair. The stated indications for Xue Yu Tan were accelerated wound healing and blood clotting.
In the early 1800s, when proteins were still being called albuminoids (albumin was a well known protein at that time), many different kinds of proteins were being discovered. Around 1849, the word “keratin” appears in the literature to describe the material that made up hard tissues such as animal horns and hooves (keratin comes from the Greek “kera” meaning horn). This new protein intrigued scientists because it did not behave like other proteins. For example, the normal methods used for dissolving proteins were ineffective with keratin. Although methods such as burning and grinding had been known for some time, many scientists and inventors were more interested in dissolving hair and horns in order to make better products.
The resolution to this insolubility problem came from a trade more than 700 years old—the tanning industry. In the years preceding World War I, lime was applied to the manufacture of keratin gels. In a United States patent issued in 1905, John Hoffmeier described a process for extracting keratins from animal horns using lime (German Pat No. 184,915, Dec. 18, 1905). He then used the extracted keratins to make gels that could be strengthened by adding formaldehyde (formaldehyde “crosslinking” is a popular method of strengthening such gels and is still used today to “fix” tissues containing structural proteins like keratin and collagen).
During the years from 1905 to 1935, many methods were developed to extract keratins using oxidative and reductive chemistries (Breinl F and Baudisch O, Z physiol Chem 1907; 52:158-69; Neuberg C, U.S. Pat. No. 926,999, Jul. 6, 1909; Lissizin T, Biochem Bull 1915; 4:18-23; Zdenko S, Z physiol Chem 1924; 136:160-72; Lissizin T, Z physiol Chem 1928; 173:309-11). By the late 1920s many techniques had been developed for breaking down the structures of hair, horns, and hooves, but scientists were confused by the behavior of some of these purified proteins. Scientists soon concluded that many different forms of keratin were present in these extracts, and that the hair fiber must be a complex structure, not simply a strand of protein. In 1934, a key research paper was published that described different types of keratins, distinguished primarily by having different molecular weights (Goddard DR and Michaelis L, J Biol Chem 1934; 106:605-14). This seminal paper demonstrated that there were many different keratin homologs, and that each played a different role in the structure and function of the hair follicle.
It was during the years of World War II and immediately after that one of the most comprehensive research projects on the structure and chemistry of hair fibers was undertaken. Driven by the commercialization of synthetic fibers such as Nylon and polyester, Australian scientists were charged with protecting the country's huge wool industry. Synthetic fibers were seen as a threat to Australia's dominance in wool production, and the Council for Scientific and Industrial Research (later the Commonwealth Scientific and Industrial Research Organisation or CSIRO) established the Division of Protein Chemistry in 1940. The goal of this fundamental research was to better understand the structure and chemistry of fibers so that the potential applications of wool and keratins could be expanded.
CSIRO scientists developed many methods for the extraction, separation, and identification of keratins. In 1965, CSIRO scientist W. Gordon Crewther and his colleagues published the definitive text on the chemistry of keratins (Crewther W G et al., The Chemistry of Keratins. Anfinsen C B Jr et al., editors. Advances in Protein Chemistry 1965. Academic Press. New York: 191-346). This chapter in Advances in Protein Chemistry contained references to more than 640 published studies on keratins. Once scientists knew how to extract keratins from hair fibers, purify and characterize them, the number of derivative materials that could be produced with keratins grew exponentially. In the decade beginning in 1970, methods to form extracted keratins into powders, films, gels, coatings, fibers, and foams were being developed and published by several research groups throughout the world (Anker C A, U.S. Pat. No. 3,642,498, Feb. 15, 1972; Kawano Y and Okamoto S, Kagaku To Seibutsu 1975; 13(5):291-223; Okamoto S, Nippon Shokuhin Kogyo Gakkaishi 1977; 24(1):40-50). All of these methods made use of the oxidative and reductive chemistries developed decades earlier.
In 1982, Japanese scientists published the first study describing the use of a keratin coating on vascular grafts as a way to eliminate blood clotting (Noishiki Y et al., Kobunshi Ronbunshu 1982; 39(4):221-7), as well as experiments on the biocompatibility of keratins (Ito H et al., Kobunshi Ronbunshu 1982; 39(4):249-56). Soon thereafter in 1985, two researchers from the UK published a review article speculating on the prospect of using keratin as the building block for new biomaterials development (Jarman T and Light J, World Biotech Rep 1985; 1:505-12). In 1992, the development and testing of a host of keratin-based biomaterials was the subject of a doctoral thesis for French graduate student Isabelle Valherie (Valherie I and Gagnieu C. Chemical modifications of keratins: Preparation of biomaterials and study of their physical, physiochemical and biological properties. Doctoral thesis. Inst Natl Sci Appl Lyon, France 1992). Soon thereafter, Japanese scientists published a commentary in 1993 on the prominent position keratins could take at the forefront of biomaterials development (Various Authors, Kogyo Zairyo 1993; 41 (15) Special issue 2:106-9).
Taken together, the aforementioned body of published work is illustrative of the unique chemical, physical, and biological properties of keratins. However, there remains a need to create optimal fractionations of keratins that have superior biomedical activity.
SUMMARY OF THE INVENTION
The invention provides methods of making charged (i.e. acidic and basic) keratins by separating one from the other, e.g., by chromatography, and optionally further processing or purifying the retained fraction or fractions. In some embodiments, the keratins fractionated based on acidity consist essentially of alpha keratoses, gamma keratoses, or mixtures thereof. In other embodiments, the keratins fractionated consist essentially of alpha kerateines, gamma kerateines, or mixtures thereof.
Another aspect of the present invention is an implantable biomedical device, comprising: a substrate and a keratin derivative on the substrate, wherein the keratin derivative is present in an amount effective to reduce cell and tissue adhesion to the substrate. In some embodiments the keratin derivative comprises, consists of or consists essentially of basic alpha keratose, basic gamma keratose, basic alpha kerateine, basic gamma kerateine, or combinations thereof.
A further aspect of the present invention is an implantable anti-adhesive tissue barrier, comprising: a solid, physiologically acceptable substrate; and a keratin derivative on the substrate. In some embodiments the keratin derivative comprises, consists of or consists essentially of basic alpha keratose, basic gamma keratose, basic alpha kerateine, basic gamma kerateine, or combinations thereof.
Yet another aspect of the present invention is a method of treating blood coagulation in a subject in need thereof, comprising administering a keratin derivative to said subject in an amount effective to inhibit blood coagulation in said subject, wherein said keratin derivative consists essentially of basic keratose, basic kerateine, or combinations thereof.
Another aspect of the present invention is the use of a keratin derivative as described herein for the preparation of a composition or medicament for carrying out a method of treatment as described herein, or for making an article of manufacture as described herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The unique properties of subfamilies of keratins can be revealed and utilized through more sophisticated means of purification.
“Subjects” (or “patients”) to be treated with the methods and compositions described herein include both human subjects and animal subjects (particularly other mammalian subjects such as dogs, cats, horses, monkeys, etc.) for veterinary purposes. Human subjects are particularly preferred. The subjects may be male or female and may be any age, including neonate, infant, juvenile, adolescent, adult, and geriatric subjects.
The disclosures of all United States patent references cited herein are to be incorporated herein by reference.
The ability of extracted keratin solutions to spontaneously self-assemble at the micron scale was published in two papers in 1986 and 1987 (Thomas H et al., Int J Biol Macromol 1986; 8:258-64; van de Löcht M, Melliand Textilberichte 1987; 10:780-6). This phenomenon is not surprising given the highly controlled superstructure whence hair keratins are obtained. When processed correctly, this ability to self-assemble can be preserved and used to create regular architectures on a size scale conducive to cellular infiltration. When keratins are hydrolyzed (e.g., with acids or bases), their molecular weight is reduced and they lose the ability to self-assemble. Therefore, processing conditions that minimize hydrolysis are preferred.
This ability to self-assemble is a particularly useful characteristic for tissue engineering scaffolds for two reasons. First, self-assembly results in a highly regular structure with reproducible architectures, dimensionality, and porosity. Second, the fact that these architectures form of their own accord under benign conditions allows for the incorporation of cells as the matrix is formed. These two features are critically important to any system that attempts to mimic the native extracellular matrix (ECM).
Cellular recognition is also an important characteristic of biomaterials that seek to mimic the ECM. Such recognition is facilitated by the binding of cell surface integrins to specific amino acid motifs presented by the constituent ECM proteins. Predominant proteins include collagen and fibronectin, both of which have been extensively studied with regard to cell binding. Both proteins contain several regions that support attachment by a wide variety of cell types. It has been shown that in addition to the widely know Arginine-Glycine-Aspartic Acid (RGD) motif, the “X”-Aspartic Acid-“Y” motif on fibronectin is also recognized by the integrin α4β1, where X equals Glycine, Leucine, or Glutamic Acid, and Y equals Serine or Valine. Keratin-biomaterials derived from human hair contain these same binding motifs. A search of the NCBI protein database revealed sequences for 71 discrete, unique human hair keratin proteins. Of these, 55 are from the high molecular weight, low sulfur, alpha-helical family. This group of proteins is often referred to as the alpha-keratins and is responsible for imparting toughness to human hair fibers. These alpha-keratins have molecular weights greater than 40 kDa and an average cysteine (the main amino acid responsible for inter- and intramolecular protein bonding) content of 4.8 mole percent. Moreover, analysis of the amino acid sequences of these alpha keratin proteins showed that 78% contain at least one fibronectin-like integrin receptor binding motif, and 25% contain at least two or more. Two recent papers have highlighted the fact that these binding sites are likely present on the surface of keratin biomaterials by demonstrating excellent cell adhesion onto processed keratin foams (Tachibana A et al., J Biotech 2002; 93:165-70; Tachibana A et al., Biomaterials 2005; 26(3):297-302).
Other examples of natural polymers that may be utilized in a similar fashion to the disclosed keratin preparations include, but are not limited to, collagen, gelatin, fibronectin, vitronectin, laminin, fibrin, mucin, elastin, nidogen (entactin), proteoglycans, etc. (See, e.g., U.S. Pat. No. 5,691,203 to Katsuen et al.).
There are two theories for the biological activity of human hair extracts. The first is that the human hair keratins (“HHKs”) themselves are biologically active. Over 70 human hair keratins are known and their cDNA-derived sequences published. However, the full compliment of HHKs is unknown and estimates of over 100 have been proposed (Gillespie J M, The structural proteins of hair: isolation characterization, and regulation of biosynthesis. Goldsmith L A (editor), Biochemistry and physiology of the skin (1983), Oxford University Press. New York; 475-510). Within the complete range of HHKs are a small number that have been shown to participate in wound contracture and cell migration (Martin, P, Science 1997; 276:75-81). In particular, keratins K-6 and K-16 are expressed in the epidermis during wound healing and are also found in the outer root sheath of the hair follicle (Bowden P E, Molecular Aspects of Dermatology (1993), John Wiley & Sons, Inc., Chichester: 19-54). The presence of these HHKs in extracts of human hair, and their subsequent dosing directly into a wound bed, may be responsible for “shortcutting” the otherwise lengthy process of differentiation, migration, and proliferation, or for alleviating some biochemical deficiency, thereby accelerating the tissue repair and regeneration process.
It has been known for more than a decade that growth factors such as bone morphogenetic protein-4 (BMP-4) and other members of the transforming growth factors (TGF-β) superfamily are present in developing hair follicles (Jones C M et al., Development 1991; 111:531-42; Lyons K M et al., Development 1990; 109:833-44; Blessings M et al., Genes and Develop 1993; 7:204-15). In fact, more than 30 growth factors and cytokines are involved in the growth of a cycling hair follicle (Hardy M H, Trends Genet 1992; 8(2):55-61; Stenn K S et al., J Dermato Sci 1994; 7S:S109-24; Rogers G E, Int J Dev Biol 2004; 48(2-3):163-70). Many of these molecules have a pivotal role in the regeneration of a variety of tissues. It is highly probable that a number of growth factors become entrained within human hair when cytokines bind to stem cells residing in the bulge region of the hair follicle (Panteleyev A A et al., J Cell Sci 2001; 114:3419-31). These growth factors would most certainly be extracted along with the keratins from end-cut human hair. This observation is not without precedent, as it has previously been shown that many different types of growth factors are present in the extracts of various tissues, and that their activity is maintained even after chemical extraction. Observations such as these show mounting evidence that a number of growth factors may be present in end-cut human hair, and that the keratins may be acting as a highly effective delivery matrix of, inter alia, these growth factors.
Keratins are a family of proteins found in the hair, skin, and other tissues of vertebrates. Hair is a unique source of human keratins because it is one of the few human tissues that is readily available and inexpensive. Although other sources of keratins are acceptable feedstocks for the present invention, (e.g. wool, fur, horns, hooves, beaks, feathers, scales, and the like), human hair is preferred for use with human subjects because of its biocompatibility.
Keratins can be extracted from human hair fibers by oxidation or reduction using methods that have been published in the art (See, e.g., Crewther W G et al. The chemistry of keratins, in Advances in protein chemistry 1965; 20:191-346). These methods typically employ a two-step process whereby the crosslinked structure of keratins is broken down by either oxidation or reduction. In these reactions, the disulfide bonds in cysteine amino acid residues are cleaved, rendering the keratins soluble (Scheme 1). The cuticle is essentially unaffected by this treatment, so the majority of the keratins remain trapped within the cuticle's protective structure. In order to extract these keratins, a second step using a denaturing solution must be employed. Alternatively, in the case of reduction reactions, these steps can be combined. Denaturing solutions known in the art include urea, transition metal hydroxides, surfactant solutions, and combinations thereof. Preferred methods use aqueous solutions of tris in concentrations between 0.1 and 1.0 M, and urea solutions between 0.1 and 10M, for oxidation and reduction reactions, respectively.
If one employs an oxidative treatment, the resulting keratins are referred to as “keratoses.”. If a reductive treatment is used, the resulting keratins are referred to as “kerateines” (See Scheme 1)
Crude extracts of keratins, regardless of redox state, can be further refined into “gamma” and “alpha” fractions, e.g., by isoelectric precipitation. High molecular weight keratins, or “alpha keratins,” (alpha helical), are thought to derive from the microfibrillar regions of the hair follicle, and typically range in molecular weight from about 40-85 kiloDaltons. Low molecular weight keratins, or “gamma keratins,” (globular), are thought to derive from the extracellular matrix regions of the hair follicle, and typically range in molecular weight from about 10-15 kiloDaltons. (See Crewther W G et al. The chemistry of keratins, in Advances in Protein Chemistry 1965; 20:191-346)
Even though alpha and gamma keratins possess unique properties, the properties of subfamilies of both alpha and gamma keratins can only be revealed through more sophisticated means of purification. For example, keratins may be fractionated into “acidic” and “basic” protein fractions. A preferred method of fractionation is ion exchange chromatography. These fractions possess unique properties, such as their differential effects on blood cell aggregation (See Table 1 below; See also: U.S. Patent Application Publication No. 2006/0051732).
“Keratin derivative” as used herein refers to any keratin fractionation, derivative, subfamily, etc., or mixtures thereof, alone or in combination with other keratin derivatives or other ingredients, including but not limited to alpha keratose, gamma keratose, alpha kerateine, gamma kerateine, meta keratin, keratin intermediate filaments, and combinations thereof, including the acidic and basic constituents thereof unless specified otherwise, along with variations thereof that will be apparent to persons skilled in the art in view of the present disclosure. In some embodiments, the keratin derivative comprises, consists or consists essentially of a particular fraction or subfraction of keratin. The derivative may comprise, consist or consist essentially of at least 80, 90, 95 or 99 percent by weight of said fraction or subfraction (or more).
In some embodiments, the keratin derivative comprises, consists of, or consists essentially of acidic alpha keratose.
In some embodiments, the keratin derivative comprises, consists of or consists essentially of alpha keratose, where the alpha keratose comprises, consists of or consists essentially of at least 80, 90, 95 or 99 percent by weight of acidic alpha keratose (or more), and where the alpha keratose comprises, consists of, or consists essentially of not more than 20, 10, 5 or 1 percent by weight of basic alpha keratose (or less).
In some embodiments, the keratin derivative comprises, consists of, or consists essentially of basic alpha keratose.
In some embodiments, the keratin derivative comprises, consists of or consists essentially of alpha keratose, where the alpha keratose comprises, consists of or consists essentially of at least 80, 90, 95 or 99 percent by weight of basic alpha keratose (or more), and where the alpha keratose comprises, consists of or consists essentially of not more than 20, 10, 5 or 1 percent by weight of acidic alpha keratose (or less).
In some embodiments, the keratin derivative comprises, consists of, or consists essentially of acidic alpha kerateine.
In some embodiments, the keratin derivative comprises, consists of or consists essentially of alpha kerateine, where the alpha kerateine comprises, consists of or consists essentially of at least 80, 90, 95 or 99 percent by weight of acidic alpha kerateine (or more), and where the alpha kerateine comprises, consists of or consists essentially of not more than 20, 10, 5 or 1 percent by weight of basic alpha kerateine (or less).
In some embodiments, the keratin derivative comprises, consists of, or consists essentially of basic alpha kerateine.
In some embodiments, the keratin derivative comprises, consists of or consists essentially of alpha kerateine, where the alpha kerateine comprises, consists of or consists essentially of at least 80, 90, 95 or 99 percent by weight of basic alpha kerateine (or more), and where the alpha kerateine comprises, consists of or consists essentially of not more than 20, 10, 5 or 1 percent by weight of acidic alpha kerateine (or less).
In some embodiments, the keratin derivative comprises, consists of or consists essentially of unfractionated alpha+gamma-kerateines. In some embodiments, the keratin derivative comprises, consists of or consists essentially of acidic alpha+gamma-kerateines. In some embodiments, the keratin derivative comprises, consists of or consists essentially of basic alpha+gamma-kerateines.
In some embodiments, the keratin derivative comprises, consists of or consists essentially of unfractionated alpha+gamma-keratose. In some embodiments, the keratin derivative comprises, consists of or consists essentially of acidic alpha+gamma-keratose. In some embodiments, the keratin derivative comprises, consists of or consists essentially of basic alpha+gamma-keratose.
In some embodiments, the keratin derivative comprises, consists of or consists essentially of unfractionated beta-keratose (e.g., derived from cuticle). In some embodiments, the keratin derivative comprises, consists of or consists essentially of basic beta-keratose. In some embodiments, the keratin derivative comprises, consists of or consists essentially of acidic beta-keratose.
The basic alpha keratose is preferably produced by separating basic alpha keratose from a mixture comprising acidic and basic alpha keratose, e.g., by ion exchange chromatography, and optionally the basic alpha keratose has an average molecular weight of from 10 to 100 or 200 kiloDaltons. More preferably, the average molecular weight is from 30 or 40 to 90 or 100 kiloDaltons. Optionally but preferably the process further comprises the steps of re-disolving said basic alpha-keratose in a denaturing and/or buffering solution, optionally in the presence of a chelating agent to complex trace metals, and then re-precipitating the basic alpha keratose from the denaturing solution. It will be appreciated that the composition preferably contains not more than 5, 2, 1, or 0.1 percent by weight of acidic alpha keratose, or less.
The acidic alpha keratose is preferably produced by a reciprocal of the foregoing technique; that is, by separating and retaining acidic alpha keratose from a mixture of acidic and basic alpha keratose, e.g., by ion exchange chromatography, and optionally the acidic alpha keratose has an average molecular weight of from 10 to 100 or 200 kiloDaltons. More preferably, the average molecular weight is from 30 or 40 to 90 or 100 kiloDaltons. Optionally but preferably the process further comprises the steps of re-dissolving said acidic alpha-keratose in a denaturing solution and/or buffering solution, optionally in the presence of a chelating agent to complex trace metals, and then re-precipitating the basic alpha keratose from the denaturing solution. It will be appreciated that the composition preferably contains not more than 5, 2, 1, or 0.1 percent by weight of basic alpha keratose, or less.
Basic and acidic fractions of other keratoses can be prepared in like manner as described above for basic and acidic alpha keratose.
The basic alpha kerateine is preferably produced by separating basic alpha kerateine from a mixture of acidic and basic alpha kerateine, e.g., by ion exchange chromatography, and optionally the basic alpha kerateine has an average molecular weight of from 10 to 100 or 200 kiloDaltons. More preferably, the average molecular weight is from 30 or 40 to 90 or 100 kiloDaltons. Optionally but preferably the process further comprises the steps of re-dissolving said basic alpha-kerateine in a denaturing and/or buffering solution, optionally in the presence of a chelating agent to complex trace metals, and then re-precipitating the basic alpha kerateine from the denaturing solution. It will be appreciated that the composition preferably contains not more than 5, 2, 1, or 0.1 percent by weight of acidic alpha kerateine, or less.
The acidic alpha kerateine is preferably produced by a reciprocal of the foregoing technique: that is, by separating and retaining acidic alpha kerateine from a mixture of acidic and basic alpha kerateine, e.g., by ion exchange chromatography, and optionally the acidic alpha kerateine has an average molecular weight of from 10 to 100 or 200 kiloDaltons. Optionally but preferably the process further comprises the steps of re-dissolving said acidic alpha-kerateine in a denaturing and/or buffering solution), optionally in the presence of a chelating agent to complex trace metals, and then re-precipitating the basic alpha kerateine from the denaturing solution. It will be appreciated that the composition preferably contains not more than 5, 2, 1, or 0.1 percent by weight of basic alpha kerateine, or less.
Basic and acidic fractions of other kerateines can be prepared in like manner as described above for basic and acidic alpha kerateine.
Keratin materials are derived from any suitable source, including, but not limited to, wool and human hair. In one embodiment keratin is derived from end-cut human hair, obtained from barbershops and salons. The material is washed in hot water and mild detergent, dried, and extracted with a nonpolar organic solvent (typically hexane or ether) to remove residual oil prior to use.
Keratoses. Keratose fractions are obtained by any suitable technique. In one embodiment they are obtained using the method of Alexander and coworkers (P. Alexander et al., Biochem. J. 46, 27-32 (1950)). Basically, the hair is reacted with an aqueous solution of peracetic acid at concentrations of less than ten percent at room temperature for 24 hours. The solution is filtered and the alpha-keratose fraction precipitated by addition of mineral acid to a pH of approximately 4. The alpha-keratose is separated by filtration, washed with additional acid, followed by dehydration with alcohol, and then freeze dried. Increased purity can be achieved by re-dissolving the keratose in a denaturing solution such as 7M urea, aqueous ammonium hydroxide solution, or 20 mM tris base buffer solution (e.g., Trizma® base), re-precipitating, re-dissolving, dialyzing against deionized water, and re-precipitating at pH 4.
A preferred method for the production of keratoses is by oxidation with hydrogen peroxide, peracetic acid, or performic acid. A most preferred oxidant is peracetic acid. Preferred concentrations range from 1 to 10 weight/volume percent (w/v %), the most preferred being approximately 2 w/v %. Those skilled in the art will recognize that slight modifications to the concentration can be made to effect varying degrees of oxidation, with concomitant alterations in reaction time, temperature, and liquid to solid ratio. It has also been discussed by Crewther et al. that performic acid offers the advantage of minimal peptide bond cleavage compared to peracetic acid. However, peractic acid offers the advantages of cost and availability. A preferred oxidation temperature is between 0 and 100 degrees Celsius (° C.). A most preferred oxidation temperature is 37° C. A preferred oxidation time is between 0.5 and 24 hours. A most preferred oxidation time is 12 hours. A preferred liquid to solid ratio is from 5 to 100:1. A most preferred ratio is 20:1. After oxidation, the hair is rinsed free of residual oxidant using a copious amount of distilled water.
The keratoses can be extracted from the oxidized hair using an aqueous solution of a denaturing agent. Protein denaturants are well known in the art, but preferred solutions include urea, transition metal hydroxides (e.g. sodium and potassium hydroxide), ammonium hydroxide, and tris(hydroxymethyl)aminomethane (tris base). A preferred solution is Trizma® base (a brand of tris base) in the concentration range from 0.01 to 1M. A most preferred concentration is 0.1M. Those skilled in the art will recognize that slight modifications to the concentration can be made to effect varying degrees of extraction, with concomitant alterations in reaction time, temperature, and liquid to solid ratio. A preferred extraction temperature is between 0 and 100 degrees Celsius. A most preferred extraction-temperature is 37° C. A preferred extraction time is between 0.5 and 24 hours. A most preferred extraction time is 3 hours. A preferred liquid to solid ratio is from 5 to 100:1. A most preferred ratio is 40:1. Additional yield can be achieved with subsequent extractions with dilute solutions of tris base or deionized (DI) water. After extraction, the residual solids are removed from solution by centrifugation and/or filtration.
The crude extract can be isolated by first neutralizing the solution to a pH between 7.0 and 7.4. A most preferred pH is 7.4. Residual denaturing agent is removed by dialysis against DI water. Concentration of the dialysis retentate is followed by lyophilization or spray drying, resulting in a dry powder mixture of both gamma- and alpha-keratose. Alternately, alpha-keratose is isolated from the extract solution by dropwise addition of acid until the pH of the solution reaches approximately 4.2. Preferred acids include sulfuric, hydrochloric, and acetic. A most preferred acid is concentrated hydrochloric acid. Precipitation of the alpha fraction begins at around pH 6.0 and continues until approximately 4.2. Fractional precipitation can be utilized to isolate different ranges of protein with different isoelectric properties. Solid alpha-keratose can be recovered by centrifugation or filtration.
The alpha keratose can be further purified by re-dissolving the solids in a denaturing solution. The same denaturing solutions as those utilized for extraction can be used, however a preferred denaturing solution is tris base. Ethylene diamine tetraacetic acid (EDTA) can be added to complex and remove trace metals found in the hair. A preferred denaturing solution is 20 mM tris base with 20 mM EDTA or DI water with 20 mM EDTA. If the presence of trace metals is not detrimental to the intended application, the EDTA can be omitted. The alpha-keratose is re-precipitated from this solution by dropwise addition of hydrochloric acid to a final pH of approximately 4.2. Isolation of the solid is by centrifugation or filtration. This process can be repeated several times to further purify the alpha-keratose.
The gamma keratose fraction remains in solution at pH 4 and is isolated by addition to a water-miscible organic solvent such as alcohol, followed by filtration, dehydrated with additional alcohol, and freeze dried. Increased purity can be achieved by re-dissolving the keratose in a denaturing solution such as 7M urea, aqueous ammonium hydroxide solution, or 20 mM tris buffer solution, reducing the pH to 4 by addition of a mineral acid, removing any solids that form, neutralizing the supernatant, re-precipitating the protein with alcohol, re-dissolving, dialyzing against deionized water, and re-precipitating by addition to alcohol. The amount of alcohol consumed in these steps can be minimized by first concentrating the keratose solution by distillation.
After removal of the alpha keratose, the concentration of gamma keratose from a typical extraction solution is approximately 1-2%. The gamma keratose fraction can be isolated by addition to a water-miscible non-solvent. To effect precipitation, the gamma-keratose solution can be concentrated by evaporation of excess water. This solution can be concentrated to approximately 10-20% by removal of 90% of the water. This can be done using vacuum distillation or by falling film evaporation. After concentration, the gamma-keratose solution is added dropwise to an excess of cold non-solvent. Suitable non-solvents include ethanol, methanol, acetone, and the like. A most preferred non-solvent is ethanol. A most preferred method is to concentrate the gamma keratose solution to approximately 10 w/v % protein and add it dropwise to an 8-fold excess of cold ethanol. The precipitated gamma keratose can be isolated by centrifugation or filtration and dried. Suitable methods for drying include freeze drying (lyophilization), air drying, vacuum drying, or spray drying. A most preferred method is freeze drying.
Kerateines. Kerateine fractions can be obtained using a combination of the methods of Bradbury and Chapman (J. Bradbury et al., Aust. J. Biol. Sci. 17, 960-72 (1964)) and Goddard and Michaelis (D. Goddard et al., J. Biol. Chem. 106, 605-14 (1934)). Essentially, the cuticle of the hair fibers is removed ultrasonically in order to avoid excessive hydrolysis and allow efficient reduction of cortical disulfide bonds in a second step. The hair is placed in a solution of dichloroacetic acid and subjected to treatment with an ultrasonic probe. Further refinements of this method indicate that conditions using 80% dichloroacetic acid, solid to liquid of 1:16, and an ultrasonic power of 180 Watts are optimal (H. Ando et al., Sen'i Gakkaishi 31(3), T81-85 (1975)). Solid fragments are removed from solution by filtration, rinsed and air dried, followed by sieving to isolate the hair fibers from removed cuticle cells.
In some embodiments, following ultrasonic removal of the cuticle, alpha- and gamma-kerateines are obtained by reaction of the denuded fibers with mercaptoethanol. Specifically, a low hydrolysis method is used at acidic pH (E. Thompson et al., Aust. J. Biol. Sci. 15, 757-68 (1962)). In a typical reaction, hair is extracted for 24 hours with 4M mercaptoethanol that has been adjusted to pH 5 by addition of a small amount of potassium hydroxide in deoxygenated water containing 0.02M acetate buffer and 0.001M surfactant.
The solution is filtered and the alpha-kerateine fraction precipitated by addition of mineral acid to a pH of approximately 4. The alpha-kerateine is separated by filtration, washed with additional acid, followed by dehydration with alcohol, and then dried under vacuum. Increased purity is achieved by re-dissolving the kerateine in a denaturing solution such as 7M urea, aqueous ammonium hydroxide solution, or 20 mM tris buffer solution, re-precipitating, re-dissolving, dialyzing against deionized water, and re-precipitating at pH 4.
The gamma kerateine fraction remains in solution at pH 4 and is isolated by addition to a water-miscible organic solvent such as alcohol, followed by filtration, dehydrated with additional alcohol, and dried under vacuum. Increased purity can be achieved by re-dissolving the kerateine in a denaturing solution such as 7M urea, aqueous ammonium hydroxide solution, or 20 mM tris buffer solution, reducing the pH to 4 by addition of a mineral acid, removing any solids that form, neutralizing the supernatant, re-precipitating the protein with alcohol, re-dissolving, dialyzing against deionized water, and reprecipitating by addition to alcohol. The amount of alcohol consumed in these steps can be minimized by first concentrating the keratin solution by distillation.
In an alternate method, the kerateine fractions are obtained by reacting the hair with an aqueous solution of sodium thioglycolate.
A preferred method for the production of kerateines is by reduction of the hair with thioglycolic acid or beta-mercaptoethanol. A most preferred reductant is thioglycolic acid (TGA). Preferred concentrations range from 1 to 10M, the most preferred being approximately 1.0M. Those skilled in the art will recognize that slight modifications to the concentration can be made to effect varying degrees of reduction, with concomitant alterations in pH, reaction time, temperature, and liquid to solid ratio. A preferred pH is between 9 and 11. A most preferred pH is 10.2. The pH of the reduction solution is altered by addition of base. Preferred bases include transition metal hydroxides, sodium hydroxide, and ammonium hydroxide. A most preferred base is sodium hydroxide. The pH adjustment is effected by dropwise addition of a saturated solution of sodium hydroxide in water to the reductant solution. A preferred reduction temperature is between 0 and 100° C. A most preferred reduction temperature is 37° C. A preferred reduction time is between 0.5 and 24 hours. A most preferred reduction time is 12 hours. A preferred liquid to solid ratio is from 5 to 100:1. A most preferred ratio is 20:1. Unlike the previously described oxidation reaction, reduction is carried out at basic pH. That being the case, keratins are highly soluble in the reduction media and are expected to be extracted. The reduction solution is therefore combined with the subsequent extraction solutions and processed accordingly.
Reduced keratins are not as hydrophilic as their oxidized counterparts. As such, reduced hair fibers will not swell and split open as will oxidized hair, resulting in relatively lower yields. Another factor affecting the kinetics of the reduction/extraction process is the relative solubility of kerateines. The relative solubility rankings in water is gamma-keratose>alpha-keratose>gamma-kerateine>alpha-kerateine from most to least soluble. Consequently, extraction yields from reduced hair fibers are not as high. This being the case, subsequent extractions are conducted with additional reductant plus denaturing agent solutions. Preferred solutions for subsequent extractions include TGA plus urea, TGA plus tris base, or TGA plus sodium hydroxide. After extraction, crude fractions of alpha- and gamma-kerateine can be isolated using the procedures described for keratoses. However, precipitates of gamma- and alpha-kerateine re-form their cystine crosslinks upon exposure to oxygen. Precipitates must therefore be re-dissolved quickly to avoid insolubility during the purification stages, or precipitated in the absence of oxygen.
Residual reductant and denaturing agents can be removed from solution by dialysis. Typical dialysis conditions are 1 to 2% solution of kerateines dialyzed against DI water for 24 to 72 hours. Those skilled in the art will recognize that other methods exist for the removal of low molecular weight contaminants in addition to dialysis (e.g. microfiltration, chromatography, and the like). The use of tris base is only required for initial solubilization of the kerateines. Once dissolved, the kerateines are stable in solution without the denaturing agent. Therefore, the denaturing agent can be removed without the resultant precipitation of kerateines, so long as the pH remains at or above neutrality. The final concentration of kerateines in these purified solutions can be adjusted by the addition/removal of water.
Regardless of the form of the keratin (i.e. keratoses or kerateines), several different approaches to further purification can be employed to keratin solutions. Care must be taken, however, to choose techniques that lend themselves to keratin's unique solubility characteristics. One of the most simple separation technologies is isoelectric precipitation. In this method, proteins of differing isoelectric point can be isolated by adjusting the pH of the solution and removing the precipitated material. In the case of keratins, both gamma- and alpha-forms are soluble at pH >6.0. As the pH falls below 6, however, alpha-keratins begin to precipitate. Keratin fractions can be isolated by stopping the precipitation at a given pH and separating the precipitate by centrifugation and/or filtration. At a pH of approximately 4.2, essentially all of the alpha-keratin will have been precipitated. These separate fractions can be re-dissolved in water at neutral pH, dialyzed, concentrated, and reduced to powders by lyophilization or spray drying. However, kerateine fractions must be stored in the absence of oxygen or in dilute solution to avoid crosslinking.
Another general method for separating keratins is by chromatography. Several types of chromatography can be employed to fractionate keratin solutions including size exclusion or gel filtration chromatography, affinity chromatography, isoelectric focusing, gel electrophoresis, ion exchange chromatography, and immunoaffinity chromatography. These techniques are well known in the art and are capable of separating compounds, including proteins, by the characteristics of molecular weight, chemical functionality, isoelectric point, charge, or interactions with specific antibodies, and can be used alone or in any combination to effect high degrees of separation and resulting purity.
A preferred purification method is ion exchange (IEx) chromatography. IEx chromatography is particularly suited to protein separation owning to the amphiphilic nature of proteins in general and keratins in particular. Depending on the starting pH of the solution, and the desired fraction slated for retention, either cationic or anionic IEx (CIEx or AIEx, respectively) techniques can be used. For example, at a pH of 6 and above, both gamma- and alpha-keratins are soluble and above their isoelectric points. As such, they are anionic and can be bound to an anionic exchange resin. However, it has been discovered that a sub-fraction of keratins does not bind to a weakly anionic exchange resin and instead passes through a column packed with such resin. A preferred solution for AIEx chromatography is purified or fractionated keratin, isolated as described previously, in purified water at a concentration between 0 and 5 weight/volume %. A preferred concentration is between 0 and 4 w/v %. A most preferred concentration is approximately 2 w/v %. It is preferred to keep the ionic strength of said solution initially quite low to facilitate binding to the AIEx column. This is achieved by using a minimal amount of acid to titrate a purified water solution of the keratin to between pH 6 and 7. A most preferred pH is 6. This solution can be loaded onto an AIEx column such as DEAE-Sepharose® resin or Q-Sepharose® resin columns. A preferred column resin is DEAE-Sepharose® resin. The solution that passes through the column can be collected and further processed as described previously to isolate a fraction of acidic keratin powder.
In some embodiments the activity of the keratin matrix is enhanced by using an AIEx column to produce the keratin that may be useful for, inter alia, promoting cell adhesion. Without wishing to be bound to any particular theory, it is envisioned that the fraction that passes through an anionic column, i.e. acidic keratin, promotes cell adhesion.
Another fraction binds readily, and can be washed off the column using salting techniques known in the art. A preferred elution medium is sodium chloride solution. A preferred concentration of sodium chloride is between 0.1 and 2M. A most preferred concentration is 2M. The pH of the solution is preferred to be between 6 and 12. A most preferred pH is 12. In order to maintain stable pH during the elution process, a buffer salt can be added. A preferred buffer salt is Trizma® base. Those skilled in the art will recognize that slight modifications to the salt concentration and pH can be made to effect the elution of keratin fractions with differing properties. It is also possible to use different salt concentrations and pH's in sequence, or employ the use of salt and/or pH gradients to produce different fractions. Regardless of the approach taken, however, the column eluent can be collected and further processed as described previously to isolate fractions of basic keratin powders.
A complimentary procedure is also feasible using CIEx techniques. Namely, the keratin solution can be added to a cation exchange resin such as SP Sepharose® resin (strongly cationic) or CM Sepharose® resin (weakly cationic), and the basic fraction collected with the pass through. The retained acid keratin fraction can be isolated by salting as previously described.
Meta keratins. Meta keratins are synthesized from both the alpha and gamma fractions of kerateine using substantially the same procedures. Basically, the kerateine is dissolved in a denaturing solution such as 7M urea, aqueous ammonium hydroxide solution, or 20 mM tris buffer solution. Pure oxygen is bubbled through the solution to initiate oxidative coupling reactions of cysteine groups. The progress of the reaction is monitored by an increase in molecular weight as measured using SDS-PAGE. Oxygen is continually bubbled through the reaction solution until a doubling or tripling of molecular weight is achieved. The pH of the denaturing solution can be adjusted to neutrality to avoid hydrolysis of the proteins by addition of mineral acid.
Keratin intermediate filaments. IFs of human hair fibers are obtained using the method of Thomas and coworkers (H. Thomas et al., Int. J. Biol. Macromol. 8, 258-64 (1986)). This is essentially a chemical etching method that reacts away the keratin matrix that serves to “glue” the IFs in place, thereby leaving the IFs behind. In a typical extraction process, swelling of the cuticle and sulfitolysis of matrix proteins is achieved using 0.2M Na 2 SO 3 , 0.1M Na 2 O 6 S 4 in 8M urea and 0.1M Tris-HCl buffer at pH 9. The extraction proceeds at room temperature for 24 hours. After concentrating, the dissolved matrix keratins and IFs are precipitated by addition of zinc acetate solution to a pH of approximately 6. The IFs are then separated from the matrix keratins by dialysis against 0.05M tetraborate solution. Increased purity is obtained by precipitating the dialyzed solution with zinc acetate, redissolving the IFs in sodium citrate, dialyzing against distilled water, and then freeze drying the sample.
Further discussion of keratin preparations are found in U.S. Patent Application Publication 2006/0051732 (Van Dyke), which is incorporated by reference herein.
Formulations. Dry powders may be formed of keratin derivatives as described above in accordance with known techniques such as freeze drying (lyophilization). In some embodiments, compositions of the invention may be produced by mixing such a dry powder composition form with an aqueous solution to produce a composition comprising an electrolyte solution having said keratin derivative solubilized therein. The mixing step can be carried out at any suitable temperature, typically room temperature, and can be carried out by any suitable technique such as stirring, shaking, agitation, etc. The salts and other constituent ingredients of the electrolyte solution (e.g., all ingredients except the keratin derivative and the water) may be contained entirely in the dry powder, entirely within the aqueous composition, or may be distributed between the dry powder and the aqueous composition. For example, in some embodiments, at least a portion of the constituents of the electrolyte solution is contained in the dry powder.
The formation of a matrix comprising keratin materials such as described above can be carried out in accordance with techniques long established in the field or variations thereof that will be apparent to those skilled in the art. In some embodiments, the keratin preparation is dried and rehydrated prior to use. See, e.g., U.S. Pat. No. 2,413,983 to Lustig et al., U.S. Pat. Nos. 2,236,921 to Schollkipf et al., and 3,464,825 to Anker. In preferred embodiments, the matrix, or hydrogel, is formed by re-hydration of the lyophilized material with a suitable solvent, such as water or phosphate buffered saline (PBS). The gel can be sterilized, e.g., by γ-irradiation (806 krad) using a Co60 source. Other suitable methods of forming keratin matrices include, but are not limited to, those found in U.S. Pat. No. 6,270,793 (Van Dyke et al.), U.S. Pat. No. 6,274,155 (Van Dyke et al.), U.S. Pat. No. 6,316,598 (Van Dyke et al.), 6,461,628 (Blanchard et al.), U.S. Pat. No. 6,544,548 (Siller-Jackson et al.), and U.S. Pat. No. 7,01,987 (Van Dyke).
In some composition embodiments, the keratin derivatives (particularly alpha and/or gamma kerateine and alpha and/or gamma keratose) have an average molecular weight of from about 10 to 70 or 85 or 100 kiloDaltons. Other keratin derivatives, particularly meta-keratins, may have higher average molecular weights, e.g., up to 200 or 300 kiloDaltons. In general, the keratin derivative (this term including combinations of derivatives) may be included in the composition in an amount of from about 0.1, 0.5 or 1 percent by weight up to 3, 4, 5, or 10 percent by weight. The composition when mixed preferably has a viscosity of about 1 or 1.5 to 4, 8, 10 or 20 centipoise. Viscosity at any concentration can be modulated by changing the ratio of alpha to gamma keratose.
The keratin derivative composition or formulation may optionally contain one or more active ingredients such as one or more growth factors (e.g., in an amount ranging from 0.0000001 to 1 or 5 percent by weight of the composition that comprises the keratin derivative(s)) to facilitate growth or healing, facilitate or inhibit coagulation, facilitate or inhibit cell or tissue adhesion, etc. Examples of suitable active ingredients include but are not limited to nerve growth factor, vascular endothelial growth factor, fibronectin, fibrin, laminin, acidic and basic fibroblast growth factors, testosterone, ganglioside GM-1, catalase, insulin-like growth factor-I (IGF-I), platelet-derived growth factor (PDGF), neuronal growth factor galectin-1, and combinations thereof. See, e.g., U.S. Pat. No. 6,506,727 to Hansson et al. and U.S. Pat. No. 6,890,531 to Horie et al.
As used herein, “growth factors” include molecules that promote the regeneration, growth and survival of tissue. Growth factors that are used in some embodiments of the present invention may be those naturally found in keratin extracts, or may be in the form of an additive, added to the keratin extracts or formed keratin matrices. Examples of growth factors include, but are not limited to, nerve growth factor (NGF) and other neurotrophins, platelet-derived growth factor (PDGF), erythropoietin (EPO), thrombopoietin (TPO), myostatin (GDF-8), growth differentiation factor-9 (GDF9), basic fibroblast growth factor (bFGF or FGF2), epidermal growth factor (EGF), hepatocyte growth factor CHGF), granulocyte-colony stimulating factor (G-CSF), and granulocyte-macrophage colony stimulating factor (GM-CSF). There are many structurally and evolutionarily related proteins that make up large families of growth factors, and there are numerous growth factor families, e.g., the neurotrophins (NGF, BDNF, and NT3). The neurotrophins are a family of molecules that promote the growth and survival of, inter alia, nervous tissue. Examples of neurotrophins include, but are not limited to, nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT-3), and neurotrophin 4 (NT-4). See U.S. Pat. No. 5,843,914 to Johnson, Jr. et al.; U.S. Pat. No. 5,488,099 to Persson et al.; U.S. Pat. No. 5,438,121 to Barde et al.; U.S. Pat. No. 5,235,043 to Collins et al.; and U.S. Pat. No. 6,005,081 to Burton et al.
For example, nerve growth factor (NGF) can be added to the keratin matrix composition in an amount effective to promote the regeneration, growth and survival of various tissues. The NGF is provided in concentrations ranging from 0.1 ng/mL to 1000 ng/mL. More preferably, NGF is provided in concentrations ranging from 1 ng/mL to 100 ng/mL, and most preferably 10 ng/mL to 100 ng/mL. See U.S. Pat. No. 6,063,757 to Urso.
Other examples of natural polymers that may be prepared and utilized in a similar fashion to the disclosed keratin preparations include, but are not limited to, collagen, gelatin, fibronectin, vitronectin and laminin (See, e.g., U.S. Pat. No. 5,691,203 to Katsuen et al.), with the necessary modifications apparent to those skilled in the art.
The composition is preferably sterile and non-pyrogenic. The composition may be provided preformed and aseptically packaged in a suitable container, such as a flexible polymeric bag or bottle, or a foil container, or may be provided as a kit of sterile dry powder in one container and sterile aqueous solution in a separate container for mixing just prior to use. When provided pre-formed and packaged in a sterile container the composition preferably has a shelf life of at least 4 or 6 months (up to 2 or 3 years or more) at room temperature, prior to substantial loss of viscosity (e.g., more than 10 or 20 percent) and/or substantial precipitation of the keratin derivative (e.g., settling detectable upon visual inspection).
Coatings and biomedical implants. As noted above, the present invention provides an implantable biomedical device, comprising: a substrate and a keratin derivative on the substrate, wherein the keratin derivative is present in an amount effective to reduce cell and/or tissue adhesion to the substrate. In some embodiments the keratin derivative comprises, consists of or consists essentially of basic alpha keratose, basic alpha kerateine, or combinations thereof.
The chemistry of keratins can be utilized to optimize the properties of keratin-based coatings. Alpha and gamma keratoses have inert sulfur residues. The oxidation reaction is a terminal step and results in the conversion of cystine residues into two non-reactive sulfonic acid residues. Kerateines, on the other hand, have labile sulfur residues. During the creation of the kerateines, cystine is converted to cysteine, which can be a source of further chemical modifications (See Scheme 1). One such useful reaction is oxidative sulfur-sulfur coupling. This reaction simply converts the cysteine back to cystine and reforms the crosslinks between proteins. This is a useful reaction for increasing the molecular weight of the gamma or alpha fraction of interest, which in turn will modify the bulk properties of the material. Increasing molecular weight influences material properties such as viscosity, dry film strength, gel strength, etc. Such reformed kerateines are referred to as meta keratins.
Meta keratins can be derived from the gamma or alpha fractions, or a combination of both. Oxidative re-crosslinking of the kerateines is affected by addition of an oxidizing agent such as peracetic acid or hydrogen peroxide. A preferred oxidizing agent is oxygen. This reaction can be accomplished simply by bubbling oxygen through the kerateine solution or by otherwise exposing the sample to air. Optimizing the molecular weight through the use of meta-keratins allows formulations to be optimized for a variety of properties including viscosity, film strength and elasticity, fiber strength, and hydrolytic susceptibility. Crosslinking in air works to improve biocompatibility by providing biomaterial with a minimum of foreign ingredients.
Any suitable substrate (typically a device intended for implanting into or inserting into a human or animal subject) may be coated or treated with keratin materials or keratin derivatives as described herein, including but not limited to grafts such as vascular grafts, vascular stents, catheters, leads, pacemakers, cardioverters, valves, fasteners or ports such as heart valves, etc.
The substrate may be formed from any suitable material, including but not limited to organic polymers (including stable polymers and biodegradable or bioerodable polymers), natural materials (e.g., collagen), metals (e.g., platinum, gold, stainless steel, etc.) inorganic materials such as silicon, glass, etc., and composites thereof.
Coating of the substrate may be carried out by any suitable means, such as spray coating, dip coating, or the like. In some embodiments, steps may be taken to couple or covalently couple the keratin to the substratem such as with a silane coupling agent, if so desired. The keratin derivative may be subsequently coated with another material, and/or other materials may be co-deposited with the keratin derivative, such as one or more additional active agents, stabilizers, coatings, etc.
Another aspect of the present invention is an implantable anti-adhesive tissue barrier, comprising: a solid, physiologically acceptable substrate (typically a sheet material, including but not limited to films, and woven and non-woven sheet materials formed from organic polymers or natural materials); and a keratin derivative on the substrate. In some embodiments the keratin derivative comprises, consists of or consists essentially of basic alpha keratose, basic alpha kerateine, or combinations thereof.
The present invention is explained in greater detail in the following non-limiting Examples.
EXAMPLE 1
Crude Keratose Samples
Keratose fractions were obtained using a method based on that of Alexander and coworkers. However, the method was substantially modified to minimize hydrolysis of peptide bonds. Briefly, 50 grams of clean, dry hair that was collected from a local barber shop was reacted with 1000 mL of an aqueous solution of 2 w/v % peracetic acid (PAA) at room temperature for 12 hr. The oxidized hair was recovered using a 500 micron sieve, rinsed with copious amounts of DI water, and the excess water removed. Keratoses were extracted from the oxidized hair fibers with 1000 mL of 100 mM Trizma® base. After 3 hours, the hair was separated by sieve and the liquid neutralized by dropwise addition of hydrochloric acid (HCl). Additional keratoses were extracted from the remaining hair with two subsequent extractions using 1000 mL of 0.1M Trizma® base and 1000 mL of DI water, respectively. Each time the hair was separated by sieve and the liquid neutralized with HCl. All three extracts were combined, centrifuged, and any residual solid material removed by filtration. The combined extract was purified by tangential flow dialysis against DI water with a 1 KDa nominal low molecular weight cutoff membrane. The solution was concentrated and lyophilized to produce a crude keratose powder.
EXAMPLE 2
Crude Kerateine Samples
Kerateine fractions were obtained using a modification of the method described by Goddard and Michaelis. Briefly; the hair was reacted with an aqueous solution of 1M TGA at 37° C. for 24 hours. The pH of the TGA solution had been adjusted to pH 10.2 by dropwise addition of saturated NaOH solution. The extract solution was filtered to remove the reduced hair fibers and retained. Additional keratin was extracted from the fibers by sequential extractions with 1000 mL of 100 mM TGA at pH 10.2 for 24 hours, 1000 mL of 10 mM TGA at pH 10.2 for 24 hours, and DI water at pH 10.2 for 24 hours. After each extraction, the solution was centrifuged, filtered, and added to the dialysis system. Eventually, all the extracts were combined and dialyzed against DI water with a 1 KDa nominal low molecular weight cutoff membrane. The solution was concentrated, titrated to pH 7, and stored at approximately 5% total protein concentration at 4° C. Alternately, the concentrated solution could be lyophilized and stored frozen and under nitrogen.
EXAMPLE 3
Ion Exchange Chromatography
Just prior to fractionation, keratose samples were re-dissolved in ultrapure water and titrated to pH 6 by addition of dilute HCl solution. Kerateine samples were titrated to pH 6 by careful addition of dilute HCl solution as well. The samples were loaded onto a 200 mL flash chromatography column containing either DEAE-Sepharose (weakly anionic) or Q-Sepharose (strongly anionic) exchange resin (50-100 mesh; Sigma-Aldrich, Milwaukee, Wis.) with gentle pressure and the flow through collected (acidic keratin). A small volume of 10 mM Trizma® base (approximately 200 mL) at pH 6 was used to completely wash through the sample. Basic keratin was eluted from the column with 100 mM tris base plus 2M NaCl at pH 12. Each sample was separately neutralized and dialyzed against DI water using tangential flow dialysis with a LMWCO of 1 KDa, concentrated by rotary evaporation, and freeze dried.
EXAMPLE 4
Evaluation of Viscosity and Red Blood Cell Aggregation
As previously described, a sample of alpha-keratose was produced, separated on a DEAE-Sepharose IEx column into acidic and basic fractions, dissolved in PBS, and the pH adjusted to 7.4. These solutions were prepared at 5 weight percent concentration and their RBC aggregation characteristics grossly evaluated with fresh whole human blood by mixing at a 1:1 ratio. Samples were taken after 20 minutes and evaluated by light microscopy. The ion exchange chromatography was highly effective at separating the aggregation phenomenon (data not shown). Basic alpha-keratose was essentially free from interactions with blood cells while the acidic alpha-keratose caused excessive aggregation.
Samples of acidic and basic alpha keratose, unfractionated alpha+gamma-kerateines, unfractionated alpha+gamma-keratose, and beta-keratose (derived from cuticle) were prepared at approximately 4 w/v % and pH 7.4 in phosphate buffered saline (PBS). Samples were tested for viscosity and red blood cell (RBC) aggregation. These results are shown in
TABLE 1
Results of viscosity and RBC aggregation tests on keratin solutions.
Fluid formulations were prepared at approximately 4 w/v % in PBS at
pH 7.4 and tested with human whole blood at a ratio of 1:1.
Viscosity
RBC
Sample Description
(centipoise)
Aggregation*
acidic alpha-keratose (1X AlEx)
5.65
3
acidic alpha-keratose (2X AlEx)
19.7
5
basic alpha-keratose
1.57
2
alpha + gamma-keratose (hydrolyzed)
1.12
1
alpha + gamma-kerateine (unfractionated)
1.59
2
*Degree of aggregation:
1 = none,
5 = high
The foregoing is illustrative of the present invention, and is not to be construed as limiting thereof. The invention is defined by the following claims, with equivalents of the claims to be included therein. | Methods are provided to produce optimal fractionations of charged keratins that have superior biomedical activity. Also provided are medical implants coated with these keratin preparations. Further provided are methods of treating blood coagulation in a patient in need thereof. | 0 |
RELATED APPLICATION
This application claims the benefit of priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 60/636,078 filed Dec. 15, 2004, the contents of which are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates generally to systems and methods for a personalized and/or interactive story book, and method of teaching a young reader a desired psychological and/or behavioral pattern designed to protect oneself from sexual predators through sounds of words and phrases, animal noises and background music elicited from the soft plush novelty toy via an audio signal device, which is associated with a character in the accompanying story book where there are indiciums prompting the reader to interact with the toy.
BACKGROUND OF THE INVENTION
Talking books are known and are a popular item for children, especially young children who are learning to, or have just learned to, read. The sound source, whatever its structure, is keyed to the story in the book so that the sounds produced bear some relationship to the content of the story in the form of indiciums on at least one page of the book prompting the reader to press a button on the toy, which makes the sounds; or actual words or phrases will appear as indiciums on at least on page of the story book. These types of books are enjoyable and educational for the child, and in addition they are unlimited in use in that they are able to provide an active role for the child. The child can play the sound with the toy while not reading the book, making the learning experience one in which the child can determine where and when it is used or played.
A child's interest and imagination are enhanced when the child is able to take a more active role in reading or listening to the story through the use of the associated toy. To provide a more enjoyable and educational reading and learning experience, it is desired to provide a novelty item or toy known to those of ordinary skill in the art as a stuffed toy and will appreciate that stuffed toys defined herein are for exemplary purposes only, and that other animals or mythical creatures will be created, all with a sound source that is separate from the book. The sound source produces realistic sounds of human speech or a specific animal noise exemplified in the figures below as the whinny or snort of a horse. In addition to realistic sounds, the toy will play accompanying soothing music, known to those in the art to assist in the learning process, including reading and enhancement of abstract reasoning skills. This gives the reading novelty item a greater play and educational value. By permitting the sound source to be separate from the book, the reader, particularly a young child, can more actively and more realistically act out the story along with the primary character in the book. This gives the child a greater feeling of participation in the reading process and stimulates the child's interest in the subject matter. Versions of the story will include different reading levels and sounds that are appropriate to the age and developmental ability of the reader. In story books adapted for younger readers aged 3-6, there will be more colorful, plentiful and larger pictures. A story version directed to an older child will have less pictures and more sophisticated language appropriate for that target age group.
PRIOR ART
1. U.S. Pat. No. 4,341,521A—Psychotherapeutic device to be used by a psychotherapist with a resistant or non-communicative child utilizing a puppet and book illustrating a traumatic event in the child's life.
2. U.S. Pat. No. 6,089,943A—Educational toy with barcode scanner, book and audible message teaching the alphabet and numbers.
3. U.S. Pat. No. 5,387,107A—Story book teaching behavioral pattern with photograph likeness of reader attached therein and construed to be the character within the book encouraging repetition of words to reinforce learning concepts.
4. U.S. Pat. No. 6,330,427B1—Novelty device with audio capabilities and associated book and pointer to activate audio sound within novelty device designed to stimulate an interest in reading.
5. US20020197930A1—Stuffed toy with an integral book whereby the body of the toy forms the front and back covers of the book and the pages are secured within thereby minimizing the loss of the book. As a child is more apt to know where the toy is, it thus provides entertainment and educational value of reading.
6. U.S. Pat. No. 5,746,637—Story book whereby torso of stuffed toy is attached between cardboard sheets of the back cover of the book and the back cover would have an illustration of the back, and remaining body of the toy. The front of book has internal pages attached in a conventional manner. The story could be Goldilocks and the Three Bears , and the attached stuffed toy would be a bear designed to encourage enjoyment of reading.
SUMMARY OF THE INVENTION
It is the goal and purpose of this patented invention to expedite the learning process of children with respect to protecting themselves from various deviant members of a population including, but not exclusive of, a pornographer, prostitution ring member, family member or other trusted adult, or a priest. This type of invention promotes self worth and the ability to self-protect from outside influences that would attempt to corrupt or harm the young or older child in any way. This invention is meant to enable the reader to become autonomous with respect to protecting his or her body, well-being and person, including the psyche and mental wholeness, thereby disabling an outside source from injuring or harming the child in any physical or psychological way.
The present invention generally relates to the field of talking novelty devices or toys or novelty device assemblies. More specifically, the present invention relates to a soft plush toy with a talking apparatus and associated book or picture book containing illustrations on at least one page, which conveys positive messages to very young or older children, especially messages related to acceptable behavioral and psychological patterns of safety or protection through reinforcement of statements made and understood by the child. This type of invention gives the child, a greater feeling of participation in the reading process, and stimulates the child's interest in reading and protecting herself through the use of the voice messages contained within the plush toy, and which are meant to be emanating from the mythical or fictional character within the story, as represented by the soft toy.
It is the tendency of both younger and older children to be uncommunicative or resistant to discussing these types of abuses, which renders the child less susceptible of benefiting from any sort of therapy process or learning a new behavior, particularly if the child has or is encountering intra-family or trusted adult problems described above. It was thus desired in the prior art to provide a means to bridge this communication gap of a child, and to focus on the problem(s) in a non-threatening or frightening way.
It is known to those familiar in the art to provide a children's toy in the form of a soft plush toy animal and in one embodiment, will come with a battery powered voice or music microchip type device embedded within the toy and operable by a switch via a button on the exterior of the toy. Such a microchip or device will be preprogrammed with different words, phrases, animal-like or mythical character sound messages, and will be accompanied by classical music playing in the background, each of which is operable by the user operating a mechanism in the form of a button on the exterior of the toy.
The theme of the story will be relating to, but not exclusive of sexual, verbal, physical, or emotional abuse. Some readers will already be contending with the same or similar issues or are being negatively affected in these ways by persons with alcohol or drug abuse problems. Other readers will have none of the issues described or have no contact with persons described above. The impact that a person with these types of behaviors has on the emotional and or psychological behavior and well being of a very young to an older child will be typified through events in the story book.
The reader will ideally identify with the primary human character in the story who is emotionally attached to the magical character, which will always be represented by the novelty plush toy. The magical figure represented by the novelty toy is responsible for saving the human character in the story or helping him to save himself from the offending adult and/or activity in the story and through the use of the audible messages conveyed from the toy, the reader will also learn to save himself from this type of harm.
There is provided by the present invention a psychotherapeutic and behavioral device wherein a story book setting depicts a traumatic event in the character's life, to which the reader can identify, and through the story book model the child reader is encouraged to identify with the story book character and begin to exhibit the positive behaviors depicted in the story.
It is therefore a principal objective of the present invention to provide a psychotherapeutic and behavioral device comprised of a book and a soft plush toy with an audio activator and audible device mechanism for a child to use who may or may not otherwise be capable of communicating words or phrases that will protect him or her from offensive, abusive persons.
It is a further objective of the present invention to provide a story book and character in the form of a toy that stimulates the reader to communicate in areas wherein he or she would otherwise be reluctant to speak out.
It is still another objective of the present invention to provide a psychotherapeutic and behavioral tool in the form of a book and associated toy deemed to be educational, which is useful in a broad range of situations, described above in the Summary of the Invention, and yet which is relatively inexpensive to manufacture. The present invention, together with attendant objects and advantages, will become more apparent, and will be best understood by those persons having ordinary skill in the art to which the present invention pertains with reference to the detailed description below and taken in conjunction with the accompanying drawings.
OVERVIEW
Disclosed herein is a unique, attractive and appealing children's educational book construction coupled with a soft plush toy. In accordance with the present invention there is provided an educational toy comprising a first Article having an audio device, the audio device being responsive to an output signal to produce a predetermined audio message that is described in a section of the book that relates directly to the toy and a message that is to be reinforced through an audio message. The audio message will be played based on the output signal that is generated via a button device attached on the exterior surface of the plush toy which triggers the activation device.
The first Article comprises a book, each page (and not necessarily each page) of which has a said audio message associated with it. The book will contain a cue in the form of a phrase or instruction indicium as to when the reader should activate the voice or sound from within the toy via the activator button. The story book includes a hard front and back cover, and a plurality of pages there between. The covers and the pages are bound together in a conventional manner in which books are bound. The material will initially be bound with hard front and back covers, and in later publications or releases, the book will be spiral bound as a strong paperback type of material known to those familiar with the art as a paperback. The front cover of the story book will carry indicia in the form of a title, as well as an illustration relating to the main theme or subject and one or both of the main characters addressed therein or the means to attach a likeness of the soft plush toy thereto. Each page has text printed thereon accompanied by illustrations of the character, with each page not necessarily containing an illustration. Depending upon the version of the book, and based upon the demographic and age group targeted as the reader of said book, there will be more and larger colorful pictures. Via the illustrations, it is anticipated that the reader will associate herself with the human character in the story, and in turn within the scope of the interactive environment, further reinforce the behavioral changes desired in the reader. This interaction between the reader and the character and the environment vis a vis the plush toy, is purposed to teach the reader the desired behavioral patterns of self-protection from sexual predators or other abusive types of adults. The character and plush toy are intended to encourage enthusiasm from the reader which further inspires the reader to repeatedly practice the voice messages in his or her own personal experience, thus reinforcing the behavior and enhancing the use and assimilation of those patterns.
The second Article comprises a soft plush novelty toy known to those skilled in the arts to be embodied in multiple formats, sizes and shapes. The toy is configured to resemble the same figure as relating to or being one of the primary characters in the story. Thereby the book becomes readily recognizable to the child. The novelty toy will have magical or ethereal adornments and will be attached to the toy in a fashion appropriate for the age group and adhering in strict accord with toy safety laws known to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of one embodiment of the story book with an open and frontal view of a sample of pages and illustrations whereby the character associated with the plush toy has textual words, which cue the reader that he/she should activate the voice apparatus on the toy. There is also a side view of the toy with an embodiment of a button attached which when pressed, activates words or phrases and sounds from the toy embodied in FIG. 1 as NO, or I'll tell, a horse whinny and music, illustrating the audible signal generator housing stored inside, along with the cover section comprised of a trap door and latch for which the purpose is to allow a user access to the audio device within the toy and from which the housing will be opened to change the battery. All is in accordance with the present invention.
FIG. 2 is a closed view of one embodiment of the book indicating the appearance of hard front and back covers with a title and an illustration on the cover, as well as another embodiment of a fragmentary view of the book being spirally bound containing soft covers of a cardboard type construction, and is in accordance with the present invention.
FIG. 3 is one embodiment of a view of multiple books that will indicate a series of books or age-specific versions of the book containing the same animal depicted as the character in the story embodied by the toy; or that the characters and associated words or sounds—including background music—will be different to target a separate psychological behavior specific to the reader's age group, and is in accordance with the present invention.
FIG. 4 is one embodiment of a simple diagram of an audio device and the activating button attached to it illustrating how the voice or sound activator is attached to the voice mechanism, which is then housed within the plush toy, and is in accordance with the present invention.
FIG. 5 is one embodiment of a circuit diagram illustrating a voice apparatus (with all correlated components), which will become readily apparent to those skilled in the art that certain modifications could be required for the specific purpose and definition of this invention. (See details in the Detailed Description below.) All this is in accordance with the present invention.
FIG. 6 is one embodiment of a perspective view illustrating the assembly for the audible signal generator enclosed within a housing, including wiring and mechanisms from which the sound will be emitted through a button. There will be no pull string for activating said audible signal generator. All this is in accordance with the present invention.
FIG. 7 is one embodiment of a block diagram for teaching children desired behavioral and psychological patterns of safety against child abusers of any sort based on psychologically sound practices known to those skilled in this art (as described in the Background of the Invention above), and is in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following descriptions illustrate some exemplary embodiments of the disclosed invention in detail. Those of skill in the art will recognize that there are numerous variations and modifications of this invention that are encompassed by its scope. Accordingly, the description of a certain exemplary embodiment should not be deemed to limit the scope of the present invention.
Definitions
The term comprising as used herein is synonymous with including, containing, or characterized by, and is inclusive or open-ended and does not exclude additional, unrecited elements or method steps.
Description
All references cited herein are incorporated herein by reference in their entireties. To the extent publications and patents or patent applications incorporated by reference contradict the disclosure contained in the specification, the specification is intended to supersede and/or take precedence over any such contradictory material.
The detailed description below discloses several methods and materials of the present invention. This invention is susceptible to modifications in the methods and materials, as well as alterations in the fabrication methods and equipment. Such modifications will become apparent to those skilled in the art from a consideration of this disclosure or practice of the invention disclosed herein. Consequently, it is not intended that this invention be limited to the specific embodiments disclosed herein, but that it cover all modifications and alternatives coming within the true scope and spirit of the invention as embodied in the attached claims.
The present invention provides a soft plush novelty toy or animal having a book associated with it and will be tailored to multiple applications. The soft tactile nature of the toy assists in having the child respond in a positive manner to, and form an attachment with the toy. However, it is also within the contemplation of the present invention that other figure forms will be used.
It is to be understood that while the scenes depicted in the story book [ 12 ] relate to sexual abuse, other childhood trauma situations or other serious types of abuse perpetrated by persons exemplified herein as members of a church, school, hospital worker or by said persons involving drug, alcohol, physical, or emotional abuse are also within the scope of the present invention.
There is thus described a psychotherapeutic and behavioral device which can be useful to children from the ages of 3 to 10, and not inclusive thereof, and can be particularly useful with non-verbal or non-expressive children.
One skilled in the art will realize that there has been disclosed a psychotherapeutic and behavioral story book and novelty toy that engages any child, whether withdrawn, resistant or non-verbal or compliant and verbal, and encourages the child to become involved, which stimulates self-insight, facilitates communication, aids in personal growth and self-protection, and is relatively inexpensive to manufacture.
The following detailed descriptions of the story book and the plush novelty toy are presented to enable one of the ordinary skilled in the art to make and use the invention and to incorporate it in the context of particular applications. Modifications and uses in different behavioral and psychological educational applications will be readily apparent to those skilled in the art, and the general principles defined herein will be applied to a wide range of embodiments. Thus, the present invention is not intended to be limited to the embodiments presented, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
The present invention provides a novel and useful toy and more particularly, a soft plush toy integrally incorporating a book which will be used to teach and reinforce a specific behavioral pattern relating to self-protection against sexual and other types of child abuse.
Story Book
As illustrated diagrammatically in FIGS. 1-3 , the present invention is a story book [ 12 ], associated with a soft plush novelty toy [ 10 ], having a front cover [ 12 d ] back bone [ 12 . 1 ], back cover [ 12 g ], and a plurality of pages [ 12 a , 12 b ]. The front cover [ 12 d ] and the back cover [ 12 g ] will be either of a soft or hard conventional book material. The pages are successively positioned between the front cover [ 12 d ] and the back cover [ 12 g ] and are hinged via the backbone [ 12 . 1 ]. The book will contain indiciums [ 12 . c . 1 ] as illustrated in FIG. 1 . As illustrated in FIG. 2 , the binding will be of a hard front and back cover and glued together for flipping pages in a usual manner for conventional books, or of a spiral type [ 12 h ] where the front [ 12 d ] and back covers [ 12 g ] will be made of a soft cardboard type of binding. The front cover [ 12 d ] has text [ 12 e ] printed thereon, with a title relating to a main theme or character(s) of the story book [ 12 ], and will have an illustration [ 12 f ] containing a picture of either (or both) of the main character(s) or the animal-like character who will teach or save the primary, human character appearing in the story book [ 12 ] and which is represented by the toy [ 10 ]. The story book [ 12 ] concerns a figure, animal or person fictional or imaginary to whom the young reader can readily identify.
This primary human character will be of a male or female gender and the story line will be geared toward psychologically and behaviorally known structures, and a nature or writing styles such that they will make the character more identifiable to that gender of reader, should that become relevant to the learning experience of the reader. In addition, there will be a second character who is there to teach the reader the desired behavior, and which is depicted by the soft plush toy. The figure depicted as a person in the story book will be one of the reader's age and or peer group. The second character will be depicted by the toy and will be based on a real animal or doll but will have the power of speech whereby it can prompt the reader to practice and eventually learn the desired behavioral patterns in a safe and imaginary environment; along with the magical ability to escape in some fashion represented herein as flying or swimming underwater so that the character can save the child in the story from trauma, pain or abuse in an imaginary way. The structure of the characters and associated toy makes it more easily identifiable and recognizable to the reader, which can enhance the potential of retaining the desired learned behavior.
As shown in FIGS. 1-3 , some pages will may include text only [ 12 a . 1 ] but will may also include an illustration of the character [ 12 c ], which either will or will not be specifically related to one of the messages audible from the toy. The text appearing on each individual page imparts some segment of one of the stories being expressed within the story book [ 12 ]. In addition, on any given page, a cue and the associated indicium message [ 12 c . 1 ] will be present that will encourage the reader to use the activation device, in the form of a button on the toy [ 20 ], that will cause the plush toy to emit either a word or phrase message [ 10 a ] appropriate to the animal (in this figure, a horse) as well as to the age of the reader; or a sound that is appropriate to a specific animal illustrated in FIG. 1 as a horse with a neigh, snort and whinny. There will also be various soothing types of music heard in the background of said words, phrases or sounds but not limited to just Classical types of music. This association encourages the child to read the story book [ 12 ] with enthusiasm and take the abstract lessons being expressed and learn to apply them to his or her own life.
EXAMPLE 1: “Whenever you wake up in the night and the monster comes in to your room, you must use my voice to help you say ‘NO’.” EXAMPLE 2: “He whinnied loudly and laughed.” EXAMPLE 3: “Without Ebony Dancer, Shiloh whispered in her own voice, ‘NO’. Shiloh shouted, “NO!” again even louder.” These segments, combined with other segments, provide complete stories proclaiming lessons related to the theme being communicated.
As illustrated in FIG. 3 , a series of story books [ 13 ] will be provided, each conveying a different theme of child abuse as described in the Summary of the Invention section above. A story book [ 12 ] will be individually adapted to a specific age group, wherein the story line and characters are identical but the vocabulary and writing style will be at the reading and comprehension level, both intellectually and psychologically, of the targeted age group of the reader. The themes relate to a wide range of topics pertaining to the safety and well being of the child that will promote his or her personal safety and growth, as well as psychological and emotional mental stability in the face of an adult figure attempting to abuse the child inappropriately or illegally.
A story book [ 12 ] depicting a physical and emotional safety related theme could include stories instructing the reader about interaction with strangers, family members and trusted friends or authority figures in face-to-face encounters or on the internet and how to stand up for one's rights as a child; how to establish personal boundaries safely and within the construct of the child's learning ability and psychological adaptability or threshold, in the face of personal danger from any authority figure.
There exist many themes, the stories of which will relate to each theme. The primary focus of this particular series [ 13 ] of stories and themes is that of child abuse and the saving of the main character through the use of a pet, animal or magical figure in the form of the character within the story as it is embodied by the educational soft plush toy [ 10 ], though it is not limited in scope to these topics and will be depicted in stories that will be based on face-to-face encounters or on the internet.
In summary, the story book teaches the reader desired behavioral patterns of self-protection against sexual predators, and through the incorporation of the reader's own personal experience, the reader is encouraged to identify with the human character in the story book and to trust the plush toy associated to the other story character as well which is intended to help the child save himself from the aforementioned negative adult behavior. This promotes the reader's interest and encourages the child to find his own strength through that of the human and magical characters of the story, thereby learning the positive and desired behavioral and psycho-social patterns thus enhancing the child's safety and autonomy.
Thus, with reference to FIG. 1 , the voice message generated by the audible signal generator [ 100 a ] inside the toy will be the same as the message [ 12 c . 1 ] printed on the page [ 12 a or 12 b ] of the book [ 12 ] or from the indicium message on said page prompting the child to press the button on the toy to activate the audio device. Here a page of the book will contain a message depicted above in the Detailed Description of the Preferred embodiment. Each visual message or indicium prompt on a page has an associated individual voice or sound message, which is accompanied by music stored in the memory of the toy whereby an appropriate output signal can be produced to generate a corresponding audio message [ 10 a ]. The soft toy [ 10 ] thus speaks to the child telling the child what the appropriate and desired behavior is, and how the child can use those words to protect herself from the abuse contained in the theme of the story.
Soft Plush Toy
As illustrated diagrammatically, the educational toy of the invention comprises a soft, plush toy [ 10 ] in the form of a horse and is shown in FIG. 1 , together with a book [ 12 ]. The soft plush toy [ 10 ] includes a tail portion [ 10 d ], hoof-like portions [ 10 c ], a body portion [ 10 g ], and a head portion [ 10 b ] attached thereto. It is of a soft and pliable construction and will be of a stuffed animal type construction with a soft furry surface. It will also have adornments and additional features not herein illustrated but known to those skilled in the art to be worn by a mythical, ancient or magical being or animal. [ 10 e ] indicates a cover section comprised of a trap door and latch [ 10 f ] with the purpose of allowing a user access to the audio device within the toy; wherein the audible signal generator [ 100 a ] is stored and housed [ 100 ] internally within the toy [ 10 ]. The audible signal generator [ 100 a ] will be accessed from the cover section through the latch [ 10 f ] on the trap door [ 10 e ]. The mechanism(s) that triggers the sounds from within the toy will be in the form of a button [ 20 ] attached to the toy, shown herein to reside at the top of the horse's back, on the body [ 10 g ] near the withers.
The toy carries the audible signal generator [ 100 a ] internally within a housing [ 100 ] and is opened externally via the latch [ 10 f ], with the purpose of allowing a user access to the audio device within the toy; and is conveniently located in a central point on the animal as illustrated herein as the underbelly of the horse. In FIG. 1 , the audio device is illustrated as being located within the body [ 10 g ] of the horse and will be powered by a battery [ 103 ] or by any other conventional and appropriate power source for generating an audible sound through such a device. The housing [ 100 ] and audible signal generator [ 100 a ], along with the battery [ 103 ], if required, is embedded within the body [ 10 g ] of the animal and is accessible from the bottom thereof, depending on the type of animal which is depicted by the toy [ 10 ]. The audio device will be invisible to the child and will be imbedded entirely within the plush toy [ 10 ].
It is important to note that, although shown in the shape of an animal, the soft plush toy [ 10 ] can be any desired mythical character or object and will vary widely while remaining within the scope of the present invention. The young reader will identify, become attached to, and thus learn from the soft plush toy [ 10 ], thereby attaining the desired psychological and behavioral pattern changes.
Audible Signal Generator
As illustrated diagrammatically in FIGS. 4-6 , the audible signal generator [ 100 a ] is contained within a housing [ 100 ], which is imbedded within the toy [ 10 ] and will comprise a microprocessor [ 101 ] capable of storing audio messages [ 10 a ] and sound patterns that have been pre-programmed into its memory and a battery [ 103 ] to power it.
In use a child will pick up the soft plush toy [ 10 ] and press the button [ 20 ], which will cause the audible signal generator [ 100 a ] to activate thereby causing the appropriate sound [ 10 a ] to be emitted from the toy via a speaker [ 101 e ] (amplifier and microphone included therein) within the audible signal generator [ 100 a ]. The audio message [ 10 a ] corresponds to a message [ 12 c . 1 ] contained within the story book [ 12 ], or an indicium on a page of said book that prompts the child to press the button on the toy, whereby the child repeats the voice message [ 10 a ] thereby reinforcing the positive behavioral pattern.
Referring to FIGS. 4-6 , these illustrate both simple and complex diagrams which will become apparent to those skilled in the art. More specifically, a complex circuit diagram (the audible signal generator [ 100 a ]) is illustrated in detail in FIG. 5 , and in FIG. 6 it is embodied within the housing as a small sample to illustrate it's positioning inside the toy, for creating and emitting a preferred embodiment of the audible signal from the toy [ 10 ].
FIG. 4 is a simple diagram of an audio device and the activating contact point(s) attached to it illustrating how the voice or sound activator is attached to the voice mechanism which is then housed within the plush toy item. [ 20 ] is the button, which will be attached on the exterior of the toy and in turn, will be attached to the voice mechanism wiring [ 130 ] which is wired directly to the audible signal generator [ 100 a ] within the housing [ 100 ], and which will be opened for maintenance or troubleshooting via the cover [ 100 d ] which is attached to the bottom portion of the housing through a normal type hinge [ 100 f ]. [ 101 e ] is the microphone and speaker-like device and [ 101 h ] is the CD-like capacitor device utilized to store all of the voice, music and sound messages via the MCU/Voice chip [ 101 ]. All this is in accordance with the present invention.
FIG. 5 illustrates a circuit diagram, a.k.a. audible signal generator [ 100 a ], as a preferred embodiment of it and a box in which it is housed, hereinafter referred to as the housing [ 100 ] as shown in FIG. 6 . As illustrated, this portion will be an integral (and internal) part of the plush toy [ 10 ].
The circuit [ 100 a ], the toy resistor [ 100 b ] and contact unit [ 100 c ] control the audible signal generator [ 100 a ] from within the toy [ 10 ]. The button [ 20 ] is the contact point of the signal activator, which has a contact unit [ 100 c ]. The contact unit [ 100 c ] is for use with the toy resistor [ 100 b ] (contact) on the plush toy [ 10 ]. The toy [ 10 ] includes a power source e.g., a three volt battery [ 103 ] and a switch [ 102 ]. The circuit [ 100 a ] is normally open but becomes closed when the switch [ 102 ] is closed and the contact unit [ 100 c ] of the toy [ 10 ] touches the toy resistor [ 100 b].
To obtain a specific message corresponding to a certain page of the story book [ 12 ], an impedance of the toy resistor [ 100 b ] can vary from one thousand to one million ohms. When the contact point as the button [ 20 ] on the toy [ 10 ] touches the toy resistor [ 100 b ] it electrically connects to an oscillator [ 101 a ] which causes the oscillator [ 101 a ] to produce an output waveform at a certain frequency depending on a value of the toy resistor [ 100 b ]. An exemplary oscillator is Model number MT-TK11 manufactured by HHC located in Taiwan. However, this device will be so simple that it only needs to generate the sound in a specific order that correlates to pages in the story book [ 12 ] and will not require an electrical impulse to activate it.
Thereafter, the output waveform of the oscillator [ 101 a ] is fed via a diode [ 101 b ] to an input port of a voice chip [ 101 d ]. An exemplary diode is Model number IN4148 manufactured by Phillips located in Hong Kong, and exemplary voice chips are micro controller unit MCU [ 101 ], model numbers SN67003, SN67060, and SN68063 manufactured by Sonix located in Taiwan. The voice chip [ 101 d ] counts the number of pulses of the input waveform that occur within a predetermined time period, e.g. three milliseconds. To accommodate the counting of pulse signals, the voice chip [ 101 d ] includes an oscillator [ 101 a ], which is powered by the power source [ 103 ] via a first resistor [ 101 c ]. Thereafter, to determine the specified message, the voice chip [ 101 d ] compares the counted number of pulses to an internal lookup table. The lookup table includes information corresponding to the printed subject matter found in the story book [ 12 ]. According to the lookup table, a sound output corresponding to the specified message is read out of a read-only memory (ROM) of the voice chip.
The sound output passes through an amplifier circuit which includes a second resistor [ 101 f ] connected from the sound output of the voice chip [ 101 d ] to a base of a transistor [ 101 i ], and a third resistor [ 101 g ] connected from the base of the transistor [ 101 i ] to ground. An exemplary transistor is Model number 8050 manufactured by Samsung located in South Korea; however, equivalent transistors can be used. A collector of the transistor [ 101 i ] connects to a speaker [ 101 e ], which connects to a capacitor [ 101 h ] and the power source [ 103 ] in shunt. Those of ordinary skill in the art will appreciate that the resistance and capacitance values shown in FIG. 5 are for exemplary purposes only, and that other values could be used to operate the audible signal generator [ 100 a ] (circuit) known to those skilled in the art.
There is also a situation wherein the message does not correlate to a specific page in the book but to a specific type of behavioral message introduced and taught within the story line of the story book [ 12 ]. There is also the situation wherein the sound is of a musical type and is played in the background on a track underneath or embedded within the sound message itself.
As illustrated in FIG. 6 , the housing [ 100 ] is shown in an open state with the cover [ 100 d ] in an open position to reveal the audible signal generator [ 100 a ] within. The embodiment of the circuit diagram itself, shown without true detail, is for illustration purposes only to point out how it is imbedded within the housing. The diagram illustrates how the button [ 20 ] as the contact point to the generator attaches to it via the voice mechanism wiring [ 130 ]. The housing itself is opened via a cover section comprised of a latch and trap door whereby the latch [ 10 f ] has the purpose of allowing a user access to the audio device within the toy which is then located on the trap door [ 10 e ] and opens via a standard hinge [ 100 f ]. The audible sound is emitted from the speaker [ 101 e ] through holes [ 100 e ] on the cover. The speaker [ 101 e ] capacitor (storage-like device) [ 100 h ] and power source in the form of a standard 3 volt battery [ 103 ] are also illustrated herein.
From the foregoing detailed description, it will be evident that there are changes, adaptations and modifications of the present invention, which come within the province of those skilled in the art. Thus, by way of illustrations drawn herein, and not of limitation, the three dimensional figure or plush toy animal will have an extent greater than the thickness and width as depicted; and that the toy assembly will be built, in such a way as to not depart from the spirit of the invention and be considered as within the scope thereof as limited solely by the claims appended hereto.
The embodiments described above and shown herein are illustrative and not restrictive. The scope of the invention is indicated by the claims rather than by the foregoing description and attached drawings. The invention will be embodied in other specific forms without departing from the spirit of the invention. The novelty device will include dolls, animals, and other figures as recognized by those of ordinary skill in the art. Also, the specific circuitry used to generate an audible signal is known to those skilled in the art to come in different constructions, both of basic or complex operation, without departing from the claimed invention. Accordingly, these and any other changes, which come within the scope of the claims, are intended to be embraced herein.
While there has been described what is at present considered a preferred embodiment of the invention, it will be obvious to one skilled in the art that various changes and modifications will be made therein without departing from the invention; and it is, therefore, aimed in the appended claims to cover all such changes and modifications as followed in the true spirit and scope of the invention.
Document Number Country
Date
*
Item
Code-Number-Kind Code
MM-YYYY
Name
Classification
A
U.S. Pat. No. 5,795,213
08-1998
Goodwin, Richard P.
446/279
B
U.S. Pat. No. 6,106,358
08-2000
McKenzie, Leila L.
446/299
C
U.S. Pat. No. 6,434,769
08-2002
Koenig, Eric
5/636
D
U.S. Pat. No. 5,059,149
10-1991
Stone, Timothy J.
446/73
E
U.S. Pat. No. 6,000,987
12-1999
Belin et al.
446/175
F
U.S. Pat. No. 7,261,612
08-2007
Hannigan et al.
446/175
G
U.S. Pat. No. 6,330,427
12-2001
Tabachnik, Joel B.
434/317
H
U.S. Pat. No. 7,035,583
04-2006
Ferrigno et al.
434/308
I
U.S. Pat. No. 6,160,540
12-2000
Fishkin et al.
345/184
J
U.S. Pat. No. 6,882,824
04-2005
Wood, Michael C.
434/308
K
U.S. Pat. No. 6,780,076
08-2004
Horchler et al.
446/29
L
U.S. Pat. No. 6,193,579
02-2001
Mak, Danny Wai
446/297
Keung
M
U.S. Pat. No. 5,279,514
01-1994
Lacombe et al.
446/297
N
U.S. Pat. No. 4,341,521
07-1982
Solomon, Laura B.
434/236
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07-2000
Lo, Wai Shing
446/175
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02-1995
Gunter, Larry et al.
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U.S. Pat. No. 5,746,637A
05/1998
Hunt, Waldo Henley
446/72 | A portable talking toy having an audio signal producer is provided with an educational book, which contains indiciums noted on at least one of the pages that are the same words or phrases uttered by the talking toy. The book has a plurality of numbered pages containing parts of a story. The story is used to teaching desired behavioral and psychological patterns that will aid the reader in learning how to self protect from sexual predators. The talking toy is provided with a pressure switch in the form of a button attached externally to the toy causing a sound to be emitted from the electronic voice box stored inside the toy. It will may have memory capable of storing and emitting words and sounds/words associated with indiciums noted in the story book and a microphone device for providing audible signals that enable sound, including music stored with each specific sound as background. The specific words communicate messages related to desired behavioral patterns. The books will contain multiple illustrations and indicium prompts indicating when the reader should press the button on the toy to hear the word or sound. Interaction between the characters in said book is purposed to encourage self-awareness in a reader encouraging him/her to pull cord or press the button on the toy thereby reinforcing the learning of the desired behavioral patterns. | 6 |
RELATED APPLICATIONS
[0001] The application claims the benefit of U.S. Provisional Patent Application No. 62/144,898, filed Apr. 8, 2015.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] In general, the present invention relates to counterbalance systems for windows that prevent open window sashes from moving under the force of their own weight. More particularly, the present invention system relates to the structure of both the brake shoe and window track stops that help inhibit the unintentional movement, known in the industry as drift, of a window sash during use.
[0004] 2. Description of the Prior Art
[0005] There are many types and styles of windows. One of the most common types of window is the double-hung window. Double-hung windows are the window of choice for most home construction applications. A double-hung window consists of an upper window sash and a lower window sash. Either the upper window sash or the lower window sash can be selectively opened and closed by a person sliding the sash up and down within the window frame.
[0006] A popular variation of the double-hung window is the tilt-in double-hung window. Tilt-in double-hung windows have sashes that can be selectively moved up and down. Additionally, the sashes can be selectively tilted into the home so that the exterior of the sashes can be cleaned from within the home.
[0007] The sash of a double-hung window can be very heavy. The weight of the window sash depends upon both the materials used to make the window sash and the size of the window sash. Since the sashes of a double-hung window are free to move up and down within the frame of a window, some counterbalancing system must be used to prevent the window sashes from constantly moving to the bottom of the window frame under the force of their own weight.
[0008] Modern tilt-in double-hung windows are primarily manufactured in one of two ways. There are vinyl frame windows and wooden frame windows. In the window manufacturing industry, different types of counterbalance systems are traditionally used for vinyl frame windows than for wooden frame windows. The present invention is mainly concerned with the structure of vinyl frame windows. As such, the prior art concerning vinyl frame windows is herein addressed.
[0009] Vinyl frame, tilt-in, double-hung windows are typically manufactured with guide tracks along the inside of the window frame. Brake shoe assemblies, commonly known as “shoes” in the window industry, are placed in the guide tracks and ride up and down within the guide tracks. Each sash of the window has two tilt pins or tilt posts that extend into the shoes and cause the shoes to ride up and down in the guide tracks as the window sashes are opened or closed.
[0010] The shoes contain a brake mechanism that is activated by the tilt post of the window sash when the window sash is tilted inwardly away from the window frame. The shoe therefore locks the tilt post in place and prevents the base of the sash from moving up or down in the window frame once the sash is tilted open. Furthermore, the brake shoes are attached to coil springs inside the guide tracks of the window assembly. Coil springs are constant force springs, made from a coiled length of metal ribbon. The coil springs supply the counterbalance force needed to suspend the weight of the window sash.
[0011] Small tilt-in windows have small, relatively light window sashes. Such small sashes may only require a single coil spring on either side of the window sash to generate the required counterbalance forces. However, due to the space restrictions present in modern tilt-in window assemblies, larger springs cannot be used for heavier window sashes. Rather, multiple small coil springs are ganged together to provide the needed counterbalance force. A large tilt-in window sash may have up to eight coil springs to provide the needed counterbalance force.
[0012] The coil springs used to counterbalance the weight of a window sash typically only approximate the weight of the window sash. Often, the upward force of the coil springs is slightly less than the downward force of gravity. A window manufacturer, therefore, relies on friction to retain the window in an open position. However, as windows wear, surfaces become smooth and friction can be significantly reduced. Accordingly, when a window sash is fully open, it may begin to drift closed without being touched. Furthermore, when an upper window sash is being opened, it creates friction against the lower window sash that it passes. If the lower window sash is opened, then the movement can cause the open upper window sash to drift closed.
[0013] A need therefore exists for a system and method that can prevent a window sash from drifting under the force of its own weight as friction forces vary over time. This need is met by the present invention as described and claimed below.
SUMMARY OF THE INVENTION
[0014] The present invention is a system and method for inhibiting inadvertent movement of a window sash out of a fully open position. The window sash is set in guide tracks that run along the sides of the overall window assembly. The window sash is a tilt-in window with pivot posts that engage brake shoes. The brake shoes travel up and down in the guide tracks as the window sash is moved between a fully open position and a fully closed position.
[0015] A stop is mounted within the guide tracks. The brake shoe and the stop contact and interconnect when the window sash is moved to its fully open position. The brake shoe is separable from the stop when a closing force is manually applied to the window sash that acts to move the window sash away from its fully open position. The force applied must exceed a threshold level. In this manner, the window sash will remain in its fully open position and will not inadvertently drift closed due to gravity, vibrations or contact with another window sash.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] For a better understanding of the present invention, reference is made to the following description of exemplary embodiments thereof, considered in conjunction with the accompanying drawings, in which:
[0017] FIG. 1 is an exploded perspective view of a section of a tilt-in window assembly containing a counterbalance system in accordance with the present invention;
[0018] FIG. 2 is an end view of the embodiment of the system shown in FIG. 1 , shown in an unengaged condition;
[0019] FIG. 3 is an end view of the embodiment of the system shown in FIG. 2 , shown in an engaged condition; and
[0020] FIG. 4 is an end view of an alternate embodiment of the system, shown in an engaged condition;
DETAILED DESCRIPTION OF THE INVENTION
[0021] The features of the present invention system can be incorporated into many window counterbalance designs. However, the embodiments illustrated show only two exemplary embodiments of the system for the purpose of description. The exemplary embodiments illustrated are selected in order to set forth two of the best modes contemplated for the invention. The illustrated embodiments, however, are merely exemplary and should not be considered a limitation when interpreting the scope of the appended claims.
[0022] Referring to FIG. 1 , in conjunction with FIG. 2 , there is shown a first exemplary embodiment of a counterbalance system 10 that is used to counterbalance a window sash 12 contained within a window assembly 14 . The window sash 12 is a tilt-in window sash and therefore has pivot posts 16 that extend laterally from the bottom of the window sash 12 . Although only one pivot post 16 is illustrated, it will be understood that the window sash 12 is symmetrical and that a pivot post 16 extends from both sides of the window sash 12 .
[0023] Each pivot post 16 extends into a brake shoe assembly 20 . The brake show assembly 20 moves up and down in a guide track 18 on either side of the window sash 12 . The brake shoe assembly 20 serves multiple functions. First, the brake shoe assembly 20 is designed to move smoothly within the guide trade 18 . As such, the window sash 12 can open and close smoothly without binding or rattling. Second, the brake shoe assembly 20 engages the guide track 18 and holds the pivot post 16 of the window sash 12 in a fixed position, when the window sash 12 is tilted inwardly for cleaning or removal. Lastly, the brake shoe assembly 20 attaches to one or more coil springs 22 that are used to counterbalance the weight of the window sash 12 . The coil springs 22 are mounted in the guide track 18 at some elevation above the brake shoe assembly 20 . As such, the brake shoe assembly 20 and the window sash 12 it supports are biased upwardly by the coil springs 22 .
[0024] Each brake shoe assembly 20 includes a brake shoe housing 24 and a cam element 26 . The brake shoe housing 24 retains the cam element 26 . The cam element 26 receives the pivot post 16 extending from the window sash 12 . The brake shoe assembly 20 rides up and down in its guide track 18 . Each guide track 18 has a rear wall 29 and two side walls 27 , 28 . The brake shoe assembly 20 is sized to be just narrow enough to fit between the side walls 27 , 28 of the guide track 18 without causing excessive contact with the guide track 18 as the brake shoe assembly 20 moves up and down with the window sash 12 .
[0025] The brake shoe housing 24 is plastic and is preferably unistructurally molded as a single unit that requires no assembly. The brake shoe housing 24 is generally U-shaped, having a first arm element 30 and a second arm element 32 that are interconnected by a thin bottom section 34 . In the shown embodiment, the coil spring 22 attaches to the first arm element 30 . In the preferred embodiment, the second arm element 32 has a length that is at least twenty-five percent longer than that of the first arm element 30 . This prevents the coil spring 22 from being able to twist or cock within the brake shoe housing 24 in the guide track 18 .
[0026] A generally circular cam opening 36 is formed between the first arm element 30 , the second arm element 32 and the bottom section 34 . Above the cam opening 36 , the first arm element 30 and the second arm element 32 are separated by a gap space 38 . The first arm element 30 has a first sloped surface 39 that faces the gap space 38 . Likewise, the second arm element 32 has a second sloped surface 41 that faces the gap space 38 . Taken together, the first sloped surface 39 and the second sloped surface 41 diverge away from each other as they ascend above the cam opening 36 . The result is that the gap space 38 has tapered sides that lead toward the cam opening 36 .
[0027] The cam element 26 is inserted into the cam opening 36 . The cam element 26 receives the pivot post 16 from the window sash 12 . The cam opening 36 and the cam element 26 are configured so that the cam element 26 will cause the cam opening 36 to enlarge as the cam element 26 rotates within the cam opening 36 . The cam element 26 can be rotated by the pivot post 16 when the window sash 12 is tilted inwardly. When rotated, the cam element 26 spreads the first arm element 30 and the second arm element 32 apart. This is achieved by the elastic flexing of the thin bottom section 34 of the brake shoe housing 24 , which acts as a living hinge. The first arm element 30 and the second arm element 32 engage the sides of the guide track 18 and lock the brake shoe assembly 20 in place within the guide track 18 .
[0028] A locking projection 44 is formed on one of the two sloped surfaces 39 , 41 . In the shown embodiment, the locking projection 44 is formed on the second sloped surface 41 . However, this position is arbitrary and its position can be reversed to be formed on the first sloped surface 39 .
[0029] A catch stop 50 is provided. The catch stop 50 is a small shaped body that is mounted to the rear wall 29 of the guide track 18 . The catch stop 50 is positioned in the guide track 18 so that the brake shoe assembly 20 contacts and interconnects with the catch stop 50 when the window sash 12 is in its fully open position.
[0030] The catch stop 50 has a curved head 52 and a catch relief 54 along one side adjacent to the curved head 52 . The curved head 52 of the catch stop 50 is sized to pass into the gap space 38 between the first sloped surface 39 and the second sloped surface 41 as the window sash 12 is fully opened. As the window sash 12 is opened, the brake shoe assembly 20 moves up the guide track 18 until it contacts the catch stop 50 . As the window sash 12 reaches its fully open position, the catch stop 50 advances between the sloped surfaces 39 , 41 of the first arm element 30 and the second arm element 32 .
[0031] Referring to FIG. 3 in conjunction with FIG. 2 and FIG. 1 , it can be understood that the initial contact between the locking projection 44 and the curved head 52 of the catch stop 50 causes the gap space 38 to spread. This makes it a little harder to move the window sash 12 , since the brake shoe assembly 20 is engaging the guide track 18 with increased force. This provides a tactile indication to a person that the window sash 12 is almost at its fully open position. Upon a slight further opening, the locking projection 44 advances into the catch relief 54 .
[0032] The presence of the locking projection 44 in the catch relief 54 creates a mechanical interconnection between the brake shoe assembly 20 and the catch stop 50 . The mechanical interconnection is sufficient to prevent the window sash 12 from drifting, due to gravity or contact with another window sash. However, the mechanical connection is tenuous. The mechanical connection can easily be overcome by manually applying a downward force of a few pounds to the window sash 12 . The preferred force is between one and five pounds. Such a downward force will pull the brake shoe assembly 20 free of the catch stop 50 , wherein the window functions in the traditional manner.
[0033] The locking projection 44 and/or the catch relief 54 can have angled surfaces that facilitate the separation of the locking projection 44 from the catch relief 54 as a downward force is applied to the window sash 12 . The angled surfaces prevent binding and excessive wear between the locking projection 44 and the catch relief 54 .
[0034] Referring to all figures, it will be understood that to utilize the present invention, the catch stops 50 are mounted into the guide tracks 18 of the window assembly 14 . Likewise, the brake shoe assemblies 20 of the present invention are used in the counterbalance system. As the window sash 12 is opened, the brake shoe assemblies 20 move toward the catch stops 50 . As the window sash 12 reaches its fully open position, the brake shoes assemblies 20 contact and interconnect with the catch stops 50 . The locking projections 44 on the brake shoes assemblies 20 enter the catch reliefs 54 in the catch stops 50 , therein creating a mechanical interconnection between the brake shoe assemblies 20 and the catch stops 50 . The mechanical interconnection is strong enough to prevent the window sash 12 from drifting closed. However, once a downward force of a few pounds is applied to the window sash 12 , the mechanical interconnection releases and the window sash 12 is free to close in the normal manner.
[0035] The connection between the catch stop 50 and the brake shoe assembly 20 can be made in many ways. There are many alternative mechanical connections, such as pawls or detents, that can create a similar temporary interconnection. Alternatively, a magnetic connection can also be used in place of the mechanical interconnection. Referring to FIG. 4 , such an alternate embodiment is shown. In FIG. 4 , magnets 60 are coupled to the brake shoe assembly 62 . Magnets 64 of the opposite polarity or ferromagnetic plates are coupled to a catch stop 50 . As the brake shoe assemblies 62 contact the catch stop 50 , there is a magnetic interconnection created between the magnets 60 , 64 . The strength of the interconnection can be engineered by controlling the strength, size and location of the magnets 60 , 64 . Preferably the magnetic connection is engineered to create an attraction force of between one and five pounds. In this manner, the magnetic connection can be undone by simply applying a slight downward force to the window sash and separating the magnets 60 , 64 .
[0036] It will be understood that the embodiments of the present invention system that are described and illustrated herein are merely exemplary and a person skilled in the art can make many variations to the embodiments shown without departing from the scope of the present invention. All such variations, modifications, and alternate embodiments are intended to be included within the scope of the present invention as defined by the claims. | A system and method for inhibiting inadvertent movement of a window sash out of a fully open position. Brake shoes travel in the guide tracks as the window sash is moved between a fully open position and a fully closed position. A stop is mounted within the guide tracks. The brake shoe and the stop contact and interconnect when the window sash is moved to its fully open position. The brake shoe is separable from the stop when a closing force is manually applied to the window sash that acts to move the window sash away from its fully open position. The force applied must exceed a threshold level. In this manner, the window sash will remain in its fully open position and will not inadvertently drift closed due to gravity, vibrations or contact with another window sash. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to a system for positioning a trim component or other part on a vehicle; and, more specifically, to a structure for positioning a grille on a vehicle.
[0004] 2. Description of Related Art
[0005] Modern vehicle manufacturers incorporate a grille on the front end of the vehicle. The grille covers an opening at the front of the vehicle allowing air flow to the radiator aiding in its function of cooling the engine. Grille design integrates both functionality and style. Modern grilles include an elegant, distinctive or authentic look, giving the vehicle a distinct visual appeal that sets it apart from similar vehicle makes and models on the road.
[0006] Typically, the grille attaches to the vehicle structure between the vehicle headlights. Given that fit and finish for vehicles is a key deliverable for overall craftsmanship of the vehicle, emphasis is placed on the headlight/grille margins. In some instances, front end parts and build tolerances result in uneven margin or gap between the grille and headlights. For example, a vehicle could have a tight margin on one side and a wide margin on the other. Regardless of the size of the margin, customers demand even and parallel margins on both sides of the grille.
[0007] Manually adjusting the grille to center and equalizing the margin or gap on either side of the grille, after the vehicle reaches the end of the assembly line, i.e., after building the vehicle, is one way to center a grille and achieve a desired look. However, on high volume vehicles, it is not practical to manually adjust the grille as this is a labor intensive and expensive process. In some instances, assembly operators at the end of line would have to uninstall parts such as air deflectors, beauty shields, hood seals etc., to get to the grille fasteners or attachments. Further, since the grille is a decorative part, there is the potential of damage during the adjustment.
SUMMARY OF THE INVENTION
[0008] An embodiment of the present invention provides a positioning device including resilient structures that positions the component. The resilient structures exert an equal and opposite force on respective reaction surfaces. The respective forces resulting in movement between adjacent resilient structures and reaction surfaces until the resilient structure forces reach equilibrium. For example, when the component is a grille placed between headlamps, the resilient structures may include springs that act between the grille and the headlamps to center the grille in the space between headlamps. Each spring acting against a respective reaction surface and generating a reaction force. The reaction forces operate to move the grill until the force exerted by opposing springs reaches equilibrium and correspondingly self-adjusting the grille within the grille opening or the space between headlamps.
[0009] In one embodiment, the springs are integrated into the grille making the assembly process unchanged for the operator. A further embodiment includes the springs being small cantilever beams deployed from the side of the grille with some interference to the reaction surface located on or adjacent the grille opening.
[0010] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0012] FIG. 1 is a perspective view of a vehicle including a grille attachment structure according to an embodiment of the present invention
[0013] FIG. 2 is a partial front perspective view of a grille and grille attachment structure according to the present invention
[0014] FIG. 3 is an enlarged partial perspective view of a portion of the grille attachment structure as set forth in FIG. 2 .
[0015] FIG. 4 is an enlarged partial perspective view of the grille attachment structure engaged with a portion of the vehicle.
[0016] FIG. 5A is an enlarged schematic side view of one example of a spring-like mechanism initially engaging a reaction surface according to the present invention.
[0017] FIG. 5B is an enlarged schematic side view of one example of a spring-like mechanism engaging a reaction surface according to the present invention illustrating the interference fit between the spring-like mechanism and the reaction surface.
[0018] FIG. 6 is a schematic view of the grille attachment structure illustrating the grill offset in the opening and having an uneven margin.
[0019] FIG. 7 is a schematic view of the grille attachment structure illustrating the grille in equilibrium and centered in an opening.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
[0021] FIG. 1 illustrates a grille, seen generally at 10 , for an automotive vehicle 12 . The vehicle 12 includes a grille opening 14 located in the front end of the vehicle 12 between the headlights 16 , 18 . This is for illustration purposes only, as the grille opening 14 may be located in various positions on the front end structure of the vehicle 12 or between various trim or body components. For example, the grille opening 14 may not extend from the first headlight 16 to the second headlight 18 . Instead, it may extend between trim components (not shown) attached to the front end structure of the vehicle and positioned adjacent the headlights 16 , 18 .
[0022] Due to the respective build tolerances in the various parts or components of the front end structure and the grille 10 there is a margin or gap 20 , 22 between the grille 10 and the vehicle 12 , in the present example the headlights 16 , 18 , when the grille 10 is placed in the grille opening 14 . During installation the margin or gap 20 , 22 can become uneven causing an aesthetically unpleasing appearance. For example, the vehicle 12 could have a tight margin or small gap on one side and a wide margin or large gap on the other side.
[0023] FIG. 2 illustrates the grille 10 including a grille centering structure, seen generally at 24 , the grille centering structure 24 operates to center the grill 10 in the grille opening 14 such that the margin or gaps 20 , 22 are even and uniform. One embodiment of the grille centering structure 24 includes a resilient structure, for example a spring-like mechanism or member 26 that centers the grille 10 in the grille opening 14 . One example of a spring-like mechanism 26 is a cantilever member 28 shown attached to a structural member, including a sidewall 30 of the grille 10 . In the present example, the grille 10 includes an integrally molded cantilever member 28 ; however, either the cantilever member 28 or the spring-like mechanism 26 may be formed separate from and attached to the grille 10 . For example, the cantilevered member 28 or spring like mechanism 26 may include a clip or attachment feature used to attach it to the grille 10 .
[0024] As illustrated, a proximal end 32 of the cantilever member 28 attaches to the sidewall 30 of the grille 10 . The distal or free end 34 extends outwardly and is spaced from the sidewall 30 . The distal or free end 34 includes an arcuate surface 36 . The cantilever member 28 has a spring stiffness that depends on the geometry of the member and the material stiffness of the member, with the ratio of force and deflection referred to as the stiffness of the member. In the disclosed example, the cantilevered member 28 has a generally rectangular cross-section having rounded edges. Cross sectional shape and edge style of the member 28 can play an important role in spring stiffness of the member 28 .
[0025] As illustrated in FIG. 3 , in the present example the cantilever member 28 has a first section 38 extending generally perpendicular to the sidewall 30 of the grille 10 . A second section 40 extends outwardly at an angle to the sidewall 30 of the grille 10 with an arcuate section or bend 42 located between the first section 38 and the second section 40 . Accordingly, the overall shape and configuration of the cantilever member 28 may be adjusted to vary its spring stiffness.
[0026] In a further example, illustrated in FIG. 3 , the cantilever member 28 includes a rib 44 . The rib 44 extends between the cantilever member 28 and the sidewall 30 similar to the web portion of an I-Beam. As with the shape and configuration of the cantilevered member 28 , the shape and configuration of the rib 44 adjusts to increase or decrease the spring stiffness. For example, the rib 44 may extend longitudinally along the second section 40 of the cantilevered member 28 . Instead of being an integral portion of the cantilever member 28 and sidewall 30 the rib 44 can be a separate or member connected either to the cantilever member 28 or sidewall 30 .
[0027] FIG. 4 illustrates the engagement or contact of the cantilever member 28 with a support plate 46 , having a reaction surface 48 , located adjacent the grille opening 14 , typically near the headlights 16 , 18 . The cantilever member 28 is designed with a certain amount of interference between the distal or free end 34 of the cantilever member 28 and the reaction surface 48 , see FIGS. 5A and 5B illustrating the interference in dotted lines. Accordingly, when the grille 10 is placed in the grille opening 14 the distal or free end 34 of the cantilever member 28 is disposed inwardly, toward the sidewall 30 generating a certain amount of reaction or spring force in the cantilever member 28 .
[0028] FIGS. 4, 5A and 5B illustrate an example of a vertically installed grille 10 wherein the grille 10 is lowered between the respective headlights 16 , 18 . In doing so, an engagement face 50 of the cantilevered member 28 engages a beveled guide surface 52 located on the support plate 46 adjacent the reaction surface 48 . The guide surface 52 operates to move or compress the distal or free end 34 of the cantilever member 28 inwardly toward the sidewall 30 . The cantilever member 28 bows or deflects inwardly until the engagement face 50 engages the reaction surface 48 thereby generating a spring force operative to urge the grille 10 laterally in the grille opening 14 away from the headlight 16 toward the center of the grille opening 14 .
[0029] As set forth below, one example of the present invention includes the grille 10 having a first and second resilient structure illustrated herein as multiple cantilevered members 28 located on an opposite sidewalls 30 . Further, the grille 10 includes first and second reaction surfaces one example thereof being multiple support plates 46 located in the grille opening 14 adjacent the respective headlights 16 , 18 . Since the cantilever members 28 are located on opposite sidewalls 30 of the grille 10 , the interference fit between the respective cantilever members 28 and support plates 46 operates to generate a reaction force that pushes the grille 10 into the center of the opening. The amount of interference depends on the predictive variance of the headlight 16 , 18 to grille 10 margin or gap 20 , 22 .
[0030] As set forth below, the reaction force between the spring-like mechanisms 26 , shown herein as cantilever members 28 , and the support plates 46 is such that even margins 20 , 22 on either side of the grille 10 produce an equal amount of reaction force by the spring-like mechanisms 26 , keeping the system in equilibrium.
[0031] FIG. 6 illustrates a free body schematic for a grille 10 system having a spring-like mechanism 26 operative to push the grille 10 to the center of the grille opening, the open area between the respective headlights 16 , 18 . Depending on the size and weight of the grille 10 , there could be one or more spring-like mechanisms 26 deployed on each side of the grille 10 and acting on corresponding support plates or members located adjacent the respective headlights 16 , 18 . As illustrated in FIG. 6 , when the grille 10 lowered into the grille opening (not shown) between the headlights 16 , 18 it is not centered, creating a wide margin or gap 20 adjacent headlight 16 and a narrow margin or gap 22 on the other side of the grille 10 adjacent headlight 18 .
[0032] Initially, the determination of spring stiffness (k) and amount of interference (X), see FIG. 5B illustrating the inward deflection of the cantilever member 28 from its original position shown in a dotted lines, depends on the inertial force (F) provided by the weight of the grille 10 , where F=kX. For example, a heavier grille 10 may need both a greater amount of interference (X) to increase the spring force and in addition may require a stiffer spring. As illustrated in FIG. 6 , when the grille 10 is off-center, there is a larger interference (X′) associated with the narrow margin 22 and a lesser interference (X) associated with the wider margin 20 . This results in an unbalanced forces F and F′ on each side of the grille 10 wherein F′=kX+kX′, where k equals the spring stiffness and kX′ is the uneven force generated due to additional compression of the spring-like mechanism 26 caused by the uneven margins 20 , 22 , specifically the narrow margin 22 .
[0033] The unbalanced forces F and F′ on each side of the grille 10 automatically adjust the position of grille 10 in the grille opening 14 . Because the force F′ is greater than the force F it acts on and shifts the grille 10 laterally until there is an equal amount of interference between the spring-like mechanisms 26 located on opposite sides of the grille 10 . FIG. 7 shows the result of an unbalanced force centering the grille 10 between the headlights 16 , 18 . As illustrated, the grille 10 achieves equilibrium (F″) along with even margins 20 , 22 from the left to right hand side headlights 16 , 18 when F″=kX+kX″ where X″=X′/2 and is the result of the unbalanced force causing the grille 10 to move laterally or slide in the grille opening 14 until equilibrium is achieved with an equal amount of interference between the opposing spring-like mechanism 26 located adjacent the respective headlights 16 , 18 . Upon achieving equilibrium, the grille 10 can then be secured to the vehicle 12 using various known means to prevent future displacement. The even margins 20 , 22 on either side of the grille 10 produce an equal amount of reaction force by the spring-like mechanisms 26 on either side of the grille 10 , keeping the system in equilibrium and the grille equidistant from the respective edges of the grille opening 14 .
[0034] Additional embodiments of the present invention include the spring-like mechanism 26 being a molded in feature on an inner or outer surface of the grille 10 . If molded in features are not possible due to tooling condition, plastic or metal spring clips can be mechanically attached to the grille 10 to deliver the same results.
[0035] The disclosed example is for a top loaded grille 10 assembly; that is, the grille 10 is inserted into the grille opening 14 in a vertical manner, from the top down. Accordingly, the spring-like mechanism 26 is oriented in a vertical direction whereby it compresses and correspondingly generates a reaction force upon installation of the grille 10 . For a horizontally loaded grille, the spring-like mechanism 26 is oriented in the horizontal direction whereby it compresses and correspondingly generates a reaction force upon installation of the grille 10 . In some cases the spring-like mechanism 26 can be part of the grille opening 14 or headlight housings with the support plate 46 and reaction surface 48 being part of the grille 10 .
[0036] The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. | A component positioning device including at least one resilient structure that centers the component. For example, a spring that acts between a grille and a grille opening to center the grille within a grille opening. The spring generating a reaction force sufficient to self-adjust the grille within the grille opening wherein opposing springs are deployed on either side of the grill with the springs exerting a force on and moving the grill until the force exerted by the opposing springs reaches equilibrium. | 1 |
This application is a continuation of Ser. No. 10/317,966, filed Dec. 12, 2002 now U.S. Pat. No. 6,767,464 which claims priority of provisional application Ser. No. 60/341,178 filed on Dec. 13, 2001, the disclosures of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to systems for treating water containing unwanted contaminants. More particularly, the present invention relates to waste water treatment systems including biological media used to aerobically and anaerobically treat solid and liquid waste in the water. Still more particularly, the present invention relates to such treatment systems for large and small-scale waste water systems. The present invention includes novel methods for effectively treating waste water in a way that minimizes the size of the system required to output high-quality, environmentally-suitable, water depleted of ammonia, nitrites, nitrates, perchlorates and other contaminants.
2. Description of the Prior Art
Waste water treatment systems are ubiquitous, from the smallest single-family residence septic system, to industrial facilities for commercial operations and municipalities large and small. It is always the object of such systems to treat for total suspended solids (TSS), biochemical oxygen demand (BOD), nitrogen compounds, E - coli, phosphorous, and virtually any other bacteria, so as to minimize the quantity of such undesirables output by the system. Various well known means have been devised for achieving such goals, with varying degrees of success and efficiency. An overriding general problem, for the most part, with such prior systems has been the scale of operation required to effectively treat that water with high-quality output. That is, for the volumes of water to be treated, the sizes of these systems are correspondingly large. This may be particularly true for relatively small-scale systems, such as single-family residences and small groupings of homes and/or buildings, where coupling to a municipal treatment system may be unsuitable.
In the array of systems designed to treat waste water, many include the use of biological treatments to accelerate the breakdown of solids and the various contaminants associated with waste water. This biological treatment involves the use of microbes having an affinity for the pollutants contained in the water. That is, rather than simply permit solids to slowly decant from the waste water, and then apply a hazardous chemical treatment designed to destroy the pollutants—along with virtually everything else in the water—these microbes are permitted to act upon the waste water. In relative terms, they act to remove the pollutants faster than if nothing were used, and do so without the hazards and difficulties associated with chemical treatment. They must, however, be permitted to reside in some type of holding tank, filter, fixed film or media in order to multiply and feed on the contaminants. Upon completion of their ingestion of the pollutants, the microbes simply die and end up as waste solids that fall to the bottom of the treatment tank or unit for subsequent removal. Some microbes may partially block the availability of surface area or volume resulting in voids of inactivity. The treated water then passes to the next stage, which may simply be some form of a leach bed, or it may be a more complex system, such as a reactor, including, but not limited to, an ultraviolet disinfection means, ozone treatment, or membrane filtration for subsequent transport to a body of water, or for recycling in non-critical uses, such as horticulture.
Unfortunately, while aerobic and anaerobic microbe treatment has significant advantages, it is not exceedingly effective in that it is necessary to provide sufficient “dwell time” or “residence time” for the microbes to “eat” enough of the pollutants so that the waste water is rendered satisfactorily contaminant-free. Of course, the extent to which contaminant removal is satisfactory is a function of governmental regulation. In any case, the volume of water that must be treated can often lead to the need for a rather large-scale treatment unit for a relatively small waste-water-generating facility. As a result, there is often a compromise in the prior systems, which compromise is associated with the contamination-removal requirements, the space available to treat the waste water output, and the cost associated with both. Some of these problems have been addressed by recirculation of the partially treated waste water for repeated treatments. Traditional wastewater treatment systems rely on effective treatment by the gradual accumulation of bacteria. This is common to all treatment schemes but especially pronounced in systems relying on vessels or containers in which air is introduced. Such systems, relying on the gradual accumulation of bacteria for treatment, inevitably will experience failure during hydraulic overload, power failure, temporary shutdown for maintenance or in response to seasonal flows. Often, during such events, the bacteria providing treatment wash through the system and after such an event, treatment efficiency is compromised.
Another problem with such prior systems has been their efficiency over a period of time of use. When the waste water to be treated requires the use of a considerable amount of biological mass, there results a problem of “plugging” of the mass. That is, as waste solids build up on the surface of the mass, or as microbes ingest the pollutants and die they do not always fall to the bottom of the tank. Instead, they become trapped at or near the surface of the mass. This plugging or blocking of the mass significantly reduces the pathways by which subsequent pollutants may pass through to underlying active microbes that are located below the surface of the mass. There are two negative results: 1) the acceleration of pollutant decay caused by microbe ingestion is canceled; and 2) water flow through the mass is reduced and possibly even stopped. It is therefore necessary to either build a substantially larger unit than would otherwise be required—in order to account for this plugging—or to expend the effort to clean the clogged system. Such maintenance may include the introduction of agitation means or the use of pressurized water for removal of dead microbes.
Several prior waste-water treatment systems have been described. These systems have apparently been designed for large- and/or small-scale treatment using biological media to accelerate contaminant reduction. For the most part, they include biological treatment as well as mechanisms designed to enhance the effectiveness of the microbial action. However, each in turn suffers from one or more deficiencies that significantly affect the ability to provide the most effective and relatively inexpensive waste treatment system.
Nitrogen in its oxidized states (e.g. as nitrates or nitrites) can seep into ground waters, causing problems in drinking water. Drinking water standards generally limit the concentration of nitrate to 5 to 10 mg/l, yet effluent from a modern treatment plant may have natural levels greater than 20 mg/l. Nitrogen in its reduced state, as ammonia, is toxic to fish, and severe limits are in effect on many streams to control the maximum concentration.
A conventional method of nitrogen removal is by biological means. With sufficient time, oxygen, and the proper mass of microorganisms, organic nitrogen is biologically converted to ammonia and then further oxidized to nitrate forms. This conversion occurs under aerobic (with oxygen) conditions, and is relatively easy to accomplish, resulting naturally under different known types of waste treatment processes. At this point the nitrogen has not been reduced in concentration, only converted to a different form.
A practical means to remove nitrate is to convert them to nitrogen gas. At this point N.sub.2 will evolve from the water and become atmospheric nitrogen. As atmospheric nitrogen, it is not a water pollutant. Nitrates are best converted to nitrogen gas by microbial action. Under anoxic conditions (without free dissolved oxygen), many common bacteria with a demand for oxygen are able to biochemically remove the oxygen from the nitrate ion, leaving nitrogen gas. This process is called biological denitrification.
For denitrification to occur, the nitrogen must first be converted to nitrates and then the bacteria must have a food source to create a demand for oxygen. This food source may be from outside, like a chemical addition of methanol, by the addition of sewage, or by the natural demand of the organisms (endogenous respiration). This natural demand must occur under conditions where free oxygen is absent.
In the conversion of organic nitrogen and ammonia to nitrates adequate aeration must be provided, and this aerobic process also results in removal of carbon. However, carbon must be present during the denitrification by dentrifying bacteria. Accordingly carbon has to be reintroduced into the system, and this is commonly done by addition of methanol in the art. The biochemical reaction which occurs when methanol is used as the carbon source results in production of nitrogen gas, carbon dioxide and water. The amount of methanol required is about three times the weight of nitrogen compounds to be removed. As is known in the art, other carbon sources can be used.
U.S. Pat. No. 4,005,010 issued to Lunt describes the use of mesh sacks containing the biological medium. The sacks are apparently designed to hold the microbes while allowing fluids to pass through. This unit nevertheless may still result in plugging in that the biological medium will likely become clogged during the course of its usage. Furthermore, the capacity of the unit is directly dependent on the wetted surface area that can be produced for microbial growth. U.S. Pat. No. 4,165,281 Kuriyama et al. describes a waste water treatment system that includes a mat designed to contain the microorganisms. A plurality of mats is disposed vertically and waste water is supposed to pass therethrough. The likelihood of plugging is greater in this unit than in the Lunt device because of the orientation of the mats and the difficulty in maintaining and/or replacing them.
U.S. Pat. No. 4,279,753 issued to Nielson et al. describes the arrangement of a plurality of treatment reactors, alternating from aerobic to anaerobic action. There may be some advantage in using a plurality of small tanks rather than one large tank to achieve the decontamination required in that dwell time is increased; however, this is certainly more costly than is necessary. Moreover, while Nielson indicates that it is necessary to address plugging problems, the technique for doing so is relatively crude and likely not completely effective. U.S. Pat. No. 4,521,311 issued to Fuchs et al. teaches the use of a filtering bed through which the waste water passes and which includes support bedding to suspend the biological medium. The device has a rather complex recirculation process required in order to ensure cleaning of the bedding and the microbes. This device may experience clogging of another sort, and the bedding particles described by Fuchs are required to go through a costly operation for maintenance.
U.S. Pat. No. 5,202,027 issued to Stuth describes a sewage treatment system that includes a buoyant medium in the shape of large hollow balls designed to provide a site for microbial growth. The buoyant balls form but a small portion of the system, which includes a series of complex turbulent mixing sections. The Stuth device is relatively complex and likely requires considerable energy to operate in order to ensure the mixing apparently required.
U.S. Pat. No. 5,221,470 issued to McKinney describes a waste water treatment plant having a final filter made of a sheet of plastic. The sheet of plastic is wrapped about itself so as to form passageways designed for microbe growth. While this design may increase the surface area and, therefore, the dwell time available for microbial action, it is likely that plugging will occur as the passageway will likely fill with dead microbes over a period of time.
U.S. Pat. No. 5,342,522 relates to a method for the treatment of (raw) sewage in a package plant consisting of three bioreactors in series. The treatment is being carried out using three types of biomass. In a first step phosphate is removed by biological means and, at the same time, the chemical and biological oxygen demand is lowered in a highly loaded active sludge system, in a second step a nitrification is carried out, ammonium being converted to nitrate, and in a third step a denitrification is carried out using a carbon source such as methanol or natural gas. The nitrifying and denitrifying bioreactors are both fixed film processes. The thickness of the biofilm on the support material in the nitrifying bioreactor can be influenced by adjusting the aeration system or by adjusting the hydraulic loading. In the denitrifying bioreactor the thickness of the biofilm can be adjusted by raising the shear by means of raising the superficial velocity in the support material. The system according to the invention makes possible effective treatment of raw sewage in a highly loaded system resulting in the far-reaching removal of COD, nitrogen and phosphate. The process can be operated in an alternative mode, where the nitrifying and denitrifying bioreactors are exchanged. The mixing in the nitrifying step is advantageously maintained by aeration under the packages of support material. The denitrifying step was accomplished by means of a propeller stirrer or impeller stirrer, which may be placed centrally in the vessel, was preferably used for active proper mixing. Polacel, reticulated polyurethane or any other carrier material were described as support material for the biomass.
U.S. Pat. No. 5,185,080 describes that in the denitrification chamber, pre-measured quantities of a composite material, containing bacteria and a source of carbon as food, is introduced daily or even bi-daily to the treated wastewater. The bacteria are heterotrophic, laboratory cultured and packaged, as a loose particulate material, capsules, pellets, tablets or other shaped forms. The bacteria Pseudomonas, normally present in the ground, is claimed to be prevalent in this material. The Pseudomonas microorganism has the capability of transforming nitrates to nitrogen gas. The technology of this conversion is well known. The preferred pre-measured microbial tablet includes a carbon supply (source) for biological synthesis. The need for a carbon source is discussed in Handbook of Biological Wastewater Treatment by Henry H. Benjes, Jr., Garland STPM Press, 1980. Denitrification using suspended or fixed growth systems is also discussed in the foregoing reference.
All the above prior art methods attempt to increase the surface area or volume available to microbes for nitrification and denitrification, and thereby increase the productivity of the treatment system.
The above systems are generally referred to as fixed film media or suspended media systems in that surface area for bacteria to grow are provided by the addition of surface. The suspended media bacteria that prefer surfaces would generally predominate such surfaces. However, such surfaces are still subject to failures due to system poisonings and upsets, and may not be easily restarted after such failures, as the surfaces are then contaminated or plugged with dead microbes.
U.S. Pat. No. 4,693,827 describes the addition of a rapidly metabolized soluble or miscible organic material to be added to the carbon consuming step of the process. Heterotrophic organisms consume the added material together with soluble ammonia to generate additional organisms, resulting in the reduction of the soluble ammonia concentration in the wastewater. The rapidly metabolized material comprises one or more short chain aliphatic alcohols, short chain organic acids, aromatic alcohols, aromatics, and short chain carbohydrates.
However, if too much of the rapidly metabolizing material is not introduced in a controlled manner, the heterotrophic organism will proliferate detrimentally. On the other hand if too little is added or in the absence of carbon, the organism will slowly die. Therefore, there is a need for an efficient delivery system for introducing independently carbon and rapidly metabolizing material, bacteria, nutrients and air to such systems. In addition, there is also a need for monitoring the performance of the system as to the extent of the treatment, and feedback from the monitoring detectors to the delivery system for efficient and optimum delivery of carbon, bacteria, nutrients and air.
In U.S. Pat. Nos. 5,863,435 and 6,183,642 issued to Heijen et. al. a method is described for the biological treatment of ammonium-rich wastewater in at least one reactor which involves the wastewater being passed through the said reactor(s) with a population, obtained by natural selection in the absence of sludge retention, in the suspended state of nitrifying and denitrifying bacteria to form, in a first stage with the infeed of oxygen, a nitrite-rich wastewater and by the nitrite-rich wastewater thus obtained being subjected, in a second stage without the infeed of oxygen, to denitrification in the presence of an electron donor of inorganic or organic nature, in such a way that the contact time between the ammonium-rich wastewater and the nitrifying bacteria is at most about two days, and the pH of the medium is controlled between 6.0 and 8.5 and the excess, formed by growth, of nitrifying and denitrifying bacteria and the effluent formed by the denitrification are extracted. In addition the growth rate of the nitrifying and denitrifying bacteria is expediently controlled by means of the retention time, in the reactor, of the wastewater to be treated which is fed in. The electron donor of inorganic nature is selected from the group consisting of hydrogen gas, sulfide, sulfite and iron (III) ions, and said electron donor of organic nature is selected from the group consisting of glucose and organic acids, aldehydes and alcohols having 1–18 carbon atoms. However, such a system could fail based on washouts, introduction of toxic substances, and there will be lag time before the system performs properly. In addition, while organic solvents such as methanol are liquid, and can be introduced as liquid, they are flammable and toxic, and not preferred by many waste water system operators. Lower carbohydrates such as glucose and dextrose while non-toxic, are solids, and require special solid delivery methods to introduce into water treatment systems, and therefore not generally used in the industry. Aqueous solutions of lower carbohydrates may be used; however, such solutions are subject to premature biological degradation, and generally require introduction of antibacterial agents which are harmful for the nitrifiers and denitrifiers.
U.S. Pat. Nos. 4,465,594 and 5,588,777 disclose a wastewater treatment system that use grey water and soaps for denitrification in two different designs of wastewater systems. U.S. Patent application 20020170857 by McGrath et al. published Nov. 21, 2002 discloses the use of a detergent or a detergent like compound for the denitrification of wastewater or nitrified water of U.S. Pat. No. 5,588,777. The application also discloses heating the denitrified wastewater as well as the addition of bacteria to the mixing tank. However, soaps, detergents and detergent like compounds are generally surface active and tend to damage the cell walls of bacteria, adhere to surfaces, interfere with bacterial functions, and are more expensive than methanol. In addition, the metabolism rate of such compounds would be low and would require longer dwell times in the denitrification zones, reactors or media.
Therefore, there is a need for aqueous solution compositions of electron donor or carbon containing material which are non-flammable, liquid, stable to storage, non-toxic to the environment and wastewater microorganisms, readily metabolized, such as carbohydrates and mixtures thereof, and which can be readily introduced to defined locations in wastewater treatment systems to assist in the nitrification and denitrification of wastewaters. In addition, such compositions may also be used for the removal of perchlorates and other pollutants.
The prior art has many examples of teachings that employ bacterial compositions to accomplish, or aid in accomplishing, the biologically mediated purification of wastewater. Hiatt U.S. Pat. No. 6,025,152 describe a methods and mixtures of bacteria for aerobic biological treatment of aqueous systems polluted by nitrogen waste products. Denitrifying bacterial compositions are used in combination with solid column packings in the teachings of Francis, U.S. Pat. No. 4,043,936. These compositions are believed to belong to the family of Pseudomonas. Hater, et al U.S. Pat. No. 4,810,385 teaches a wastewater purification process involving bacterial compositions comprising, in addition to non-ionic surfactants and the lipid degrading enzymes Lipase, three strains of Bacillus subtillis, 3 strains of Pseudomonas aeruginosa, one strain of Pseudomonas stutzeri, one strain of Pseudomonas putida, and one strain of Eschericia hermanii grown on a bran base. Wong, et.al., U.S. Pat. No. 5,284,587 teaches a bacterial composition, that is in combination with enzymes and a gel support is necessary to achieve satisfactory waste treatment. Bacterial species mentioned in Wong et al are Bacillus subtillis, Bacillus licheniformis, Cellulomonas and acinetobacter lwoffi. Similarly, Wong and Lowe, U.S. Pat. No. 4,882,059 teach a process for biological treatment of wastewater comprising bacterial species that aid in the solubilization of the solid debris. The bacterial species used in the teaching of Wong and Lowe are of the following bacterial types: Bacillus amyloliquefaciens and aerobacter aerogenes. These bacterial types are taught to be employed primarily for solubilization and biodegradation of starches, proteins, lipids and cellulose present in the waste product.
Hiatt U.S. Pat. No. 6,025,152 describes the addition of bacterial mixtures in the spore form. Most water treatment systems have residence or dwell times of 2 days or less, and addition of bacteria in the spore form will lead to a substantial portion of bacteria being washed out of the system before it has time to establish, because the environment is not always conducive for bacterial growth.
U.S. Pat. No. 5,185,080 issued to Boyle discloses a system for the treatment of nitrate containing wastewater from home or commercial, not municipal, in which the wastewater is contacted underground by denitrifying bacteria introduced to the treatment zone periodically; the treatment zone being maintained at or above the temperature at which the bacteria are active on a year-round basis by the ground temperature.
U.S. Pat. No. 5,811,289 issued to Lewandowski et al. discloses an aerobic waste pretreatment process which comprises inoculating a milk industry effluent with a mixture of bacteria and yeasts both classes of microorganisms capable of living and growing in symbiosis in the effluent, the population of the bacteria being, in most cases, several times greater than the population of the yeasts, maintaining the temperature and pH of the inoculated effluent between 0.degree. C. and 50.degree. C. and between 1.7 and 9, aerating the effluent while varying, if necessary, the pH at maximum rate of 1.5 pH units per minute and also, if required, modulating the aeration of the inoculated effluent at a maximum rate of 130 micromoles of oxygen per minute.
U.S. Pat. No. 6,077,432 issued to Coppola et al. discloses a method and system for carrying out the bio-degradation of perchlorates, nitrates, hydrolysates and other energetic materials from wastewater, including process groundwater, ion exchange effluent brines, hydrolyzed energetics, drinking water and soil wash waters, which utilizes at least one microaerobic reactor having a controlled microaerobic environment and containing a mixed bacterial culture. It is claimed that using the method of invention, perchlorates, nitrates, hydrolysates and other energetics can be reduced to non-detectable concentrations, in a safe and cost effective manner, using readily available non-toxic low cost nutrients. The temperature of the reactor was maintained at 10 to 42 degrees centigrade.
European Patent Application EP 1151967A1 published Nov. 7, 2001, to Nakamura discloses a liquid microorganism preparation which contains enzymes generated by anaerobic microorganisms, facultative anaerobic microorganisms and aerobic microorganisms will be propagated in a growth tank to make microorganism enzyme water. The obtained enzyme water will be added to a grease trap that retains kitchen water which includes macromolecular organic matter, such as animal and vegetable waste oil, and will be stirred with aeration so that the enzymes and the organic materials will be in contact in order to decompose the organic matter. The decomposition residue and sludge will be separated so as to flow the supernatant water to the sewer pipe.
U.S. Patent application No.2002170857 published Nov. 21, 2002 to McGrath et al. describes a system for nitrified water that comprises a plurality of interconnected tanks including a mixing tank which feeds detention tanks which in combination provide a detention time period for the effluent. A controller determines the amount of detergent dispensed into the mixing tank in accordance with the measured volume of effluent to be treated. The mixing tank comprises a heater for maintaining the nitrified effluent temperature above 50 degrees F. The application also discloses the addition of small doses of bacteria into the mixing tank for denitrification, and heating means to heat the effluent in the mixing tank to accelerate denitrification. An optional line filter can be added to the output of the system for further reducing organic nitrogen concentration. Addition of bacteria or heating means for nitrification was not disclosed, and may be construed as being not necessary for the disclosure.
Therefore, there is a need for bacterial compositions which are not in the spore form or low growth phase, but are in the growth phase when added to the water treatment systems, will continue their growth in the water treatment systems after addition, and delivery means for such addition.
Therefore, there is a need for a waste water treatment apparatus and process that takes advantage of the useful characteristics of biological treatment in an effective manner of existing systems or new systems to be constructed. There is also a need for such an apparatus and process that maximizes the contact between contaminants from the waste water and the microbes without the need for a relatively large processing tank or unit, while providing the best conditions for the microbes to grow. Further, there is a need for an apparatus and process that is simple, energetically efficient, and sufficiently effective to reduce to desirable levels the TSS, BOD, E - Coli, nitrogen-containing compounds, phosphorus-containing compounds, and bacteria of wastewater in a cost-effective manner. In addition, there is a need for a treatment system and apparatus that can deliver microbes and nutrients optimally to enhance the efficiency and performance of the large number of water treatment systems already in operation for nitrification and denitrification without costly reengineering.
There are a large number of existing systems and apparatuses that are not performing efficiently in removing ammonia, nitrite and nitrate which could be made to perform efficiently by the current invention with relatively little cost. In addition, new systems could be made to perform efficiently by following the process described in the present invention.
SUMMARY OF THE INVENTION
The present invention relates to a system and method for treating wastewater from any mechanical or gravity system. This generally relates to placement of bacteria, enzymes, biological and chemical catalysts, such as nitrifying and denitrifying, carbon or electron donor sources and nutrients, and heating means in a system relative to oxygen and nitrogen sources, oxic, aerobic, anoxic, and anaerobic zones, using an apparatus. The apparatus may be in one or more parts. It refers to the placement of bacteria, enzymes, biological and chemical catalysts, nutrients and or electron donor, carbon sources or heating means in waste water systems in industrial, agricultural, commercial, residential, and other waste water systems; and the methods for treating pollutants or undesirable materials in waste water or polluted sites. These ingredients are frequently limiting in the efficient and proper functioning of the wastewater systems. Frequently, the bacterial species which are specific for the pollutant to be removed is not always present, or have a short life or not present in high concentrations to be effective. This will also be the case for suspended media as well as fixed film media. Therefore, there is a need for the delivery of the bacteria and electron donors in high concentration to allow for system efficiency and capacity without increasing the size or volume of the system. Furthermore, frequent testing and monitoring for the presence of the microbes is desirable to establish efficient system performance. The findings of constant demand for microbes and electron donor/carbon and micronutrients show the need for controlled addition. The volume available for fixed or suspended film surface area is small and limiting, and not all the microbes grow on surfaces. Solid media (materials) used as carbon or electron donor is not always adequate to supply the necessary electron donors due to solubility limitations, and could be supplemented by this invention.
The invention also includes stable compositions of carbon and carbon containing nutrient liquid mixtures of low viscosity which can be easily pumped, non-flammable, less damaging to beneficial bacteria, safer to handle than currently used organic solvents and less toxic to the environment when released and not subject to premature growth of bacteria and other microorganisms during storage and use. These bioremediation processes may be considered as fermentation processes applicable to pollutants, and the location placement of additives is important for the efficient functioning of these processes. The microbes can be bacteria or yeast, and other biological catalysts such as enzymes may also be used.
For example, in the case of nitrification and denitrification, methanol and other organic solvents are used as electron donors or carbon sources. However, these solvents are flammable and toxic, and its large scale use causes handling difficulties including special storage. In addition, methanol metabolism rate by many bacteria would be too slow for some systems, resulting in longer residence times and reduced productivity of treatment. Therefore there is a need for carbon sources that overcome the limitations of methanol and other carbon sources. The invention also includes alternative electron donor or carbon sources and compositions, that are less toxic and non-flammable than pure methanol and other solvents and allow for the addition of other micronutrients without precipitation, if needed to the carbon source, is not subject to premature degradation during use and storage by bacteria and other microorganisms, and possess the ability to reduce nitrates to nitrogen in the presence of denitrifying bacteria. Such alternate carbon sources include, but are not limited to carbohydrates such as glucose, fructose, dextrose, maltose, sucrose, other sugars, maltodextrins (CAS No. 9050-36-6),corn syrup solids (CAS No.68131-37-3) starches, and cellulose derivatives such as hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose and other carbon containing compounds.
Methanol in the above invention is used as a carbon source as well as a bacteriostat for the prevention of premature growth of extraneous bacteria and other microorganisms in the liquid carbon source. However, at low concentrations, methanol is generally not harmful for bacteria. In addition to methanol, a number of additives can be used to prevent premature microbial growth in the present invention. These additives can be used in addition to methanol or in the absence of methanol as a single component or combinations thereof. They include sodium hydroxide, sodium carbonate and sodium bicarbonate, and other bases with pH greater than 9. Other additives are nitro substituted compounds such as 2-Bromo-2-nitropropane-1,3-diol (CAS# 52-51-7), 5-Bromo-5-nitro-1,3-dioxane (CAS#30007-47-7)-Bromo-nitropropane-1,3-diol (CAS#52-51-7); Isothiazolones such as 5-Chloro-2-methyl-4-isothiazolin-3-one(CMI) (CAS# 26172-55-4), 2-Methyl-4-isothiazolin-3-one(MI) (CAS# 2682-20-4), Mixture of CMI:MI 3:1 (CAS # 55965-84-9, 1,2-Benzisothiazolin-3-one(CAS# 2634-33-5); Quaternary ammonium compounds such as benzyl-C8–18 alkyldimethyl ammonium chloride and Benzylalkonium chloride(CAS #, 61789-74-7,8001-54-5,68393-01-5,68424-85-1,85409-22-9), N,N,N,-trimethyl-1-hexadecane ammonium bromide (CAS # 57-09-0), N,N,N,-trimethyl-1-hexadecane ammonium chloride (CAS # 112-02-7),1-(3-Chloro-2-propenyl)-3,5,7-triaza-1-azoniatricyclo(3.3.1.1) decane chloride(CAS # 9080-31-3,4080-31-3,51229-78-8); parabans such as Butyl-4-hydroxybenzoate(CAS # 94-26-8),Ethyl-4-hydroxybenzaote (CAS # 120-47-8), Methyl-4-hydroxybenzoate (CAS # 99-76-3), Propyl-4-hydroxybenzoate (CAS # 94-13-3). Other substances that may be used are 2,2,4′-Trichloro-2′-hydroxyphenylether (CAS # 3380-34-5),Sodium Benzoate(CAS # 532-32-1), Benzyl alcohol (CAS # 100-51-6), Chloroacetamide(CAS # 79-07-2), N-(1,3-Bis hydroxy methyl)-2,5-dioxo-4-imidazolidinyl)N,N′-bis(hydroxy-methyl) urea(Diazolidinyl urea) (CAS # 35691-65-7); 1,2-Dibromo-2,4-dicyanobutan(CAS # 35691-65-7), 4,4-Dimethyl oxazolidin (CAS # 51200-87-4),Glutarldehyde(CAS # 111-30-8), formalin, 37% formaldehyde (CAS # 50-00-0). Other additives that may be also be used are sodium hydroxymethyl glycinate (CAS# 7732-18-5), imidazolidnyl urea (CAS # 39236-46-9), diazolidinyl urea (CAS # 78491-02-8) and 3-iodo-2-propynyl butyl carbamate (CAS # 55406-53-6). The above additives are added at a concentration such that premature bacterial growth is prevented in the aqueous carbon solution, and yet will not kill or inhibit the bacteria when added for the microbiological remediation reactions. The useful concentration range will vary for each compound, and may be expected to be in the 0.01% to 5% range.
Another embodiment of the invention is the use of enzymes, biological and chemical catalysts, and bacteria that will convert a useful precursor carbon or electron donor source, such as cellulose, grease, fat, oils, aliphatic and aromatic hydrocarbons, to a useful carbon or electron donor source, such as glucose,fructose, glycerol, fatty acids, alcohols, by the use of the respective enzymes, biological or chemical catalysts, or microbes. For cellulose, the enzyme cellulases or microbial cellulases may be used. These cellulases and microbial cellulases may also be added along with the nitrifiers to the anaerobic or aerobic zone, or even into the settling tanks before the aerobic zones. Other enzymes that may be used in addition to cellulase are amylase, protease, lipase, carbohydrases and combinations thereof. For esters, fats and oils, enzyme esterases may be used.
Grease, fats and oils are discharged into water treatment systems, and grease and fat traps are sometimes employed to remove these materials. Costs are incurred at regular intervals for the removal and disposal of grease and fats from these traps, especially by users processing food. For the treatment of grease, fats and oils, the enzyme lipases, lipase releasing bacteria or bacteria capable of breaking down grease and fats could be used. These would convert the grease, fats and oils to glycerine, fatty acids, mono- and diglycerides. The breakdown products can then be diverted to the aerobic or anaerobic regions of the waste water treatment system, and can perform as an additional source of electron donor or carbon for nitrification or denitrification.
For aliphatic and aromatic hydrocarbons, and compounds, enzymes and bacteria which convert these materials may be used. The products of these transformations may then be directed to another zone of the water treatment process as a reactant.
The pollutant may be a process waste product such as cyanide. In such a case a cyanide converting enzyme, a cyanidase may be used, as described in U.S. Pat. No. 5,116,744 issued to Ingvorsen et al.
The carbon or electron donor source preferably should be in the liquid form so that the apparatus can deliver known volumes at predefined flow rates. If the carbon or electron donor source is in the solid form, solid or powder delivery methods should be employed. In the liquid form the carbon or electron donor source provides flexibility as to the addition of micronutrients without precipitation or undue agglomeration. In the case of methanol which is commonly used, micronutrients cannot generally be added without precipitation, and many other components are not soluble in methanol. Even though pure or concentrated methanol or other organic solvents may be used as the carbon or electron donor source in the present invention, the apparatus may still be used with modifications for appropriate use. The electron donor source is not limited to carbon containing compounds. Any electron donor source, including inorganic electron donors such as hydrogen gas, methane, natural gas, sulfide, sulfite, and iron(III) may be used.
Another embodiment is the use of enzymes which can be genetically modified to be present in crops such as potatoes, corm and other crops, so that these can convert starch directly into electron donors, and used without further treatment.
The liquid carbon sources are made by dissolving solid or liquid carbon sources in water, and adding bacterial stabilizers to prevent premature bacterial growth, and micronutrients as needed. An example of a useful composition is about 100 g of carbohydrates mixture containing about 7.6% monosaccharides, 6.9% disaccharides, 7.0% trisaccharides, 6.8% tetrasaccharides and 71.7% tetrasaccharides and higher saccharides dissolved in 100 ml water. In addition, stabilizing agents to prevent premature microbiological growth described earlier, may be added, as well as other carbon sources which will increase the carbon content, and increase stability to microbiological growth. Examples are methanol, ethanol, ethylene glycol and glycerol, which may be added from about 3% to 40% or more as needed, without compromising flammability and solubility. Furthermore, micronutrients such as minerals, vitamins, other carbohydrates, and amino acids may be added to the aqueous carbon mixture, as needed, without precipitation. The composition and concentration of the mono and polysaccharides may be changed depending on the requirements of viscosity and concentration of the carbon or electron donor source. The monosaccharides that can be used are glucose, galactose and fructose. The disaccharides that may be used are sucrose, lactose and maltose. Monosaccharides and disaccharides will provide a carbon solution with lower viscosity, whereas the use of oligo and polysaccharides will provide a higher viscosity for the same carbon concentration. While it is convenient to use soluble carbon or electron donor sources, in cases, it may be useful to use partially soluble carbon or electon donors which gradually dissolve or breakdown by microbes or enzymes to release material at a controlled release rate. An example would be the use of soluble oligosaccharides, polysaccharides as well as insoluble polysaccharides, such as starch, or monosaccharides and polysaccharides formulated for controlled release in aerobic and anaerobic zones.
For nitrification, the apparatus is set to deliver growing nitrifying bacteria in the rapidly growing phase of growth or the end of the rapidly growing phase of growth, called the log phase of growth, to the inlet of the aerobic tank or chamber of the wastewater treatment process, but after the settling tank or the primary treatment. In addition, the apparatus has an air pump to deliver additional air to the aerobic tank or chamber. The air pump may input air by means of a distributing means such as an air diffuser. The apparatus can optionally deliver carbon and nutrients if needed for the particular process or system, based on the composition of the waste water and the stage of the treatment.
Since the bacteria are grown on the liquid carbon source of the invention, the liquid carbon source and composition may be considered to be a nitrifying and denitrifing bacterial induction media. The bacteria specifically grown in this invention is expected to be more efficient in the nitrification and denitrification metabolism
This invention also relates to a method for selecting for enzyme function in nitrifiers and denitrifiers to be available down stream in a septic system when re-exposed to the same carbon carbohydrate source. It is well known in the field of microbiology that specific requirements are needed to grow and maintain microbes. It has been shown that maintaining microbes on the same carbon source maintains a high level of induction of the appropriate enzymes needed to utilize that carbon source at a high rate of efficiency. This manifests itself in competitive utilization of the carbon source. More specifically this invention using specific carbohydrates and other nutrients such as nucleic acid fragments may be used to transform microbial communities towards nitrification and denitrification in a more consistent and rapid manner. The invention is of significant interest for the nutritional improvement of sewage related microorganisms as well as methods for obtaining the expression of particular enzymes in sewage related nitrifying and denitrifying microorganisms.
For denitrification, the apparatus is set to deliver growing denitrifying bacteria in the rapidly growing phase of growth or the end of the rapidly growing phase of growth, called the log phase of growth, to the inlet of the anaerobic tank or chamber of the wastewater treatment process where anoxic conditions are present, but after the aerobic tank or chamber. The apparatus can optionally deliver carbon and nutrients if needed for the particular process or system, based on the composition of the waste water entering the anoxic or anaerobic chamber.
In some waste water systems the aerobic or oxic and anoxic or anaerobic chambers may not be clearly separated. In such systems, mixtures of nitrifying and denitrifying bacteria are added along with carbon and nutrient sources if the system lacks such ingredients.
The location of the delivery of the bacteria and carbon sources in the reaction zones is important. For nitrification and denitrification, nitrifying bacteria and electron donors, if needed, should be added in the aerobic zone; for denitrification, in the anaerobic zone, in those regions where the oxygen concentration is lower than other regions in the zone. In addition, both the aerobic and anaerobic zones may contain mixing means such as stirrers or mixers for dispersion of the contents.
It is therefore an object of the present invention to provide a waste water treatment apparatus and process that takes advantage of the useful characteristics of biological treatment in an effective manner. It is also an object of the present invention to provide such an apparatus and process that maximizes the contact between contaminants from the waste water and the microbes. This allows inefficient systems to become efficient without the need for a relatively large processing tank or unit for smaller systems. Another object of the present invention is to provide a waste water treatment apparatus and process that is sufficiently effective so as to reduce to desirable levels the Total Suspended Solids(TSS), Biological Oxygen Demand(BOD), E - Coli, nitrogen-containing compounds, phosphorus-containing compounds, bacteria and viruses of waste water in a cost-effective manner.
These and other objectives are achieved in the present invention through an aerobic and anaerobic treatment process including the addition of specific microbes and carbon to specific locations in the aerobic and anaerobic process so that the aerobic and anaerobic processes are made efficient. The aerobic and anaerobic process may be homogeneous such as the absence of any fixed film or added suspended media, or in addition may contain fixed film or other added suspended media for a heterogeneous process, for extra locations (surface area) for the added microbes to attach and grow. In such systems, either microfiltration or ultrafiltration membranes may be used to contain the bacteria within the aerobic or anaerobic zone and remove the effluent through the membrane. If suspended media is used, screens or filters may be employed at the end of the aerobic and anaerobic zones or tanks to contain the added suspended media within the zone or tank and prevent washout, and membranes may also be used to separate suspended microbes. In addition to the specific microbes, specific carbon sources and nutrients also can be added which provide additional efficiencies to the waste treatment process. The microbes and nutrients may be added at the specific locations in a batchwise, periodic or a continuous process using an apparatus. The microbes, carbon sources, nutrients and if necessary oxygen from air may be added together or separately in the process. Heating means may be provided to maintain the aerobic and anaerobic zones in a desirable temperature range of between 10 and 37 degrees F. In addition, the timing and delivery of the microbes, nutrients and temperature are optimized for the particular process. An example of the micronutrients that may be used is described in Micronutrient Bacterial Booster, N-100, Bio-systems Corporation, Roscoe, Ill., containing the minerals described. Minerals, vitamins, carbohydrates, and amino acids may be added together, separately, or mixed with the carbon source, or microbes as needed. The efficient timing and delivery of the microbes, carbon and nutrients are achieved by the use of a specific apparatus, a controller, which forms part of the invention. This efficiency in the process results in efficient depletion of wastewater contaminants from existing systems and meet regulatory requirements imposed by regulatory agencies.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of the apparatus in accordance with one embodiment of the present invention;
FIG. 2 is FIGS. 2A and 2B are a schematic illustration of a suitable apparatus for introducing bacteria in accordance with one embodiment of the present invention;
FIG. 3 is a schematic illustration of another waste treatment system including one embodiment of the apparatus of the present invention;
FIG. 4 is a schematic illustration of yet another waste treatment system including one embodiment of the apparatus of the present invention;
FIG. 5 is a schematic illustration of still another waste treatment system including one embodiment of the apparatus of the present invention;
FIG. 6 is a schematic illustration of still another waste treatment system including one embodiment of the apparatus of the present invention;
FIG. 7 is a schematic illustration of another waste treatment system including one embodiment of the apparatus of the present invention;
FIG. 8 is a schematic illustration of yet another waste treatment system including one embodiment of the apparatus of the present invention;
FIG. 9 is a schematic illustration of still another waste treatment system including one embodiment of the apparatus of the present invention;
FIG. 10 is a schematic illustration of still another waste treatment system including one embodiment of the apparatus of the present invention;
FIG. 11 is a schematic illustration of another waste treatment system including one embodiment of the apparatus of the present invention;
FIG. 12 is a schematic illustration shown an oxic and anoxic reactor with Apparatus (“Tommy Box”) for the introduction of bacteria, carbon and air in accordance with one embodiment of the present invention;
FIG. 13 is FIGS. 13A and 13B are a schematic illustration of an embodiment of the invention for a filter system;
FIG. 14A is a schematic illustration of an embodiment of the invention for a modified nitrification/denitrification filter system;
FIG. 14B is a schematic illustration of an embodiment of the invention for a modified nitrification/denitrification filter system;
FIG. 15 is a schematic illustration of an embodiment of the invention for 1 liter reactors;
FIG. 16 is a schematic illustration of an embodiment of the invention for 1 liter reactors with fixed media in the oxic and anoxic reactors;
FIG. 17 is a comparison of the performance of the Mini OAR 1 (Fixed Film Media) and Mini OAR 2 for combined nitrogen, under different operating conditions; and
FIG. 18 is a schematic illustration of an alternative embodiment of the controller, where the layout of the different components are shown.
DETAILED DESCRIPTION OF THE INVENTION
The introduction of bacteria before or in the initial settling phase of treatment requires the bacteria to survive a significant time period, usually measured in days, in a hostile environment. The settling period provides significant challenges to survival due to the physical processes during settling. Settling also promotes the removal of larger particles that can significantly delay complete treatment due to the large mass of the particle to the size of the bacteria. After settlement, the volume to be treated is dampened in peaks and easier to treat because particle size is reduced.
Typically in the art batch pulses are fed into a system on the input end through either sinks or toilets. In accordance with the present invention, a (small) pump and actively growing microbes are placed in the post settling tank or primary treatment area as shown in FIG. 1 . The process uses a combination of nitrifiers to convert ammonia to nitrites and nitrates, and denitrifiers to convert the nitrites and nitrates to nitrogen. Preferably the microbes are in log growth phase at the time of delivery, and growing microbes and nutrients are delivered either in a batch wise, periodic or continuous manner. This is different from prior art methods where microbes in static state, non-actively growing phase or spore form are added at the input locations, where growth is slow, and the microbes may have insufficient time or nutrients to grow before they are washed out of the holding and settling tanks due to insufficient “dwell” or “residence” times. Many of these systems also require either fixed or suspended media for functioning. The use of growing microbes ensures that the density of microbes available per unit volume is very high, and therefore the volume of the tanks needed for a particular treatment will be much smaller than current waste water systems. In addition, for the same treatment tank size, the efficiency of removal of nitrogen would be enhanced, resulting in cost savings. Furthermore, in fixed film and suspended film media, there will be continuous replacement of dead and buried bacteria on the surface with fresh and growing bacteria to enhance the performance of the wastewater treatment. The tanks, in addition may contain mixing means, either by mechanical mixers or fluid mixers, for uniformly dispersing the contents added by the controller.
An additional feature of this invention is the use of heating means to maintain the temperature of the tanks or containers at the optimum temperature for the transformation and removal of the unwanted contaminants. The control means for maintaining the temperature at the optimum temperature is either included in the controller, or is provided separately, and forms part of this invention
In addition, because the microbes and nutrients are added in a controlled process, there is less likelihood of microbes not surviving. The problem of runaway growth when excessive microbes are added to settling tanks resulting in plugs and blocks of filters or tanks also is minimized. Furthermore, a particular amount of active microbes is always present, making the system catastrophic failure proof, such as in the case when toxic chemicals react with the microbes, or when the microbes are washed out in the case of rainstorms or flushes.
The particular microbes chosen depend on the nature of the waste to be cleaned, and are within the skill in the art. Generally the microbes include nitrifying bacteria for the conversion of ammonia to nitrites and nitrates. The denitrifying microbes are denitrifying bacteria that convert the nitrates and nitrites to nitrogen in the presence of the carbon sources and nutrients added in a controlled process.
Those skilled in the art know the nature of the nutrients most effective for supporting the microbes chosen. The examples below provide examples of suitable microbes. Some of the microbes can be microbes that transform phosphorus to another form that may be easily removed for example by precipitation or sedimentation. Some others will be specific for impurities such as the removal of biological oxygen demand by the removal of carbon or other oxidizable impurities which can interfere with the nitrification.
The invention is equally applicable for the remediation of waterbodies, such as ponds, lakes, aquaculture facilities, landfills, industrial wastes, and contaminated sites. A homogeneous system or a heterogeneous fixed film or suspended media may be used as appropriate. In the case of waterbodies the water can be recycled through a series of aerobic reactors to convert ammonia to nitrates and nitrites, and an anaerobic reactor to convert the nitrates and nitrites to nitrogen. In the case of industrial wastes, an appropriate microbe specific to the pollutant should be employed. In the case of contaminated soils and waste sites, water would be used to wash or percolate the site and sent to one or more vessels containing microbes and receiving growing microbes introduced by the controller. In addition, the containers and the controllers may be mounted on mobile platforms.
In the case of contaminated waste sites, such as perchiorates and chlorinated hydrocarbons, the concentrations of the contaminant may be too high in general for microbes to survive for longer periods. The continuous or periodic addition of growing microbes as described in the invention overcomes this deficiency. Any growing microbe that transforms a particular contaminant can be used. Microbes may be modified genetically to contain genes encoding enzymes that are effective in transforming the contaminants. Some examples of contaminants that may be removed or transformed by the invention by the controlled addition of microbes and if needed other nutrients are, Acetone, Ammonia, Aniline, Aromatic compounds, Nitrate, Nitrite, Carbon disulphide, Chlorinated solvents, Chlorobenzenes, Chloroform, Dichloroethanes, Dinitrotoluene, Dioxane, Ethanol, Ethylene, Explosives, Glycols, Hydrocarbons, Hydrogen sulfide, Isopentane, Isobutanes, Methanol, Methyl chloride, Methylene chloride, Tri nitro toluenes, Naththalene, Nitraamines, Nitrate, Nitroaromatics, Nitrites, Nitrobenzene, Perchlorates, Perchloroethylene, Pesticides, Phenol, Solvents, Styrene, Sulfur compounds, Tetrahydrofuran, Trichloroethane, Trichlorotoluene, Bromoform, Nitrobenzene, Methyl tertiarybutyl ether, Tertiary butyl alcohol, Chlorinated ethenes, Chlorinated ethanes, Vinyl chloride, Arnmonium perchlorate and perchlorates.
The preferred carbon/electron donor source is methanol, carbohydrates and sugars and mixtures thereof. Other carbon sources that may be used are ethanol, polysaccharides, soluble starches, oils, fats, dairy and food waste, and other sources of organic carbon. The amount of carbon that should be added is about 0.2 to about 5 times the total nitrogen present in the waste water, preferably about 2 times the total nitrogen present in the waste water.
The preferred nutrients are amino acids, phosphates, and other minerals needed by bacteria for growth.
The preferred bacteria to be used are specific for the pollutant to be treated. For denitrification, denitrifying bacteria are used. If nitrification of ammonia is the need, nitrifying bacteria would be used, and for cyanide removal “cyanidase” enzyme or bacteria capable of converting cyanide can be used. For denitrification, a mixture of Enterobacter Sakazaki (ATCC 29544), Bacillus coagulans (ATCC7050), Bacillus subtillis (ATCC 6051), Bacillus subtillis (ATCC 6051), Bacillus megatarium (ATCC7052), Bacillus licheniformis (ATCC14580), Bacillus cerus (ATCC4513) and Bacillus pasytereurii (ATCC 11859) may be used. Other bacteria that may be used are described in U.S. Pat. No. 6,025,152. For nitrification, the bacteria include Nitrobacter and Nitrocococcus spp available from Cape Cod Biochemicals, 21 Commerce Road, Bourne, Mass. These bacteria are available form a number of commercial suppliers which are specific for the specific pollutant. The bacteria are used in an amount effective to treat (and preferably eliminate) the contaminants.
Turning now to FIG. 1 , there is shown a simplified diagrammatic illustration of a preferred arrangement of the basic components of the waste water treatment system of the present invention for a small system such as a single family home. (Title V System). Waste generated in toilet (1) and water waste generator (2) enters the settling tank (3), and after a certain residence or “dwell” time enters the distribution box (4) which distributes to the leaching field (5). The distribution box can be a large tank with two zones, one for receiving oxygen and be oxic and result in nitrification, and another anoxic for denitrification, or it could simply be one tank. In the present invention an apparatus (“Tommy Box”), shown in greater detail in FIG. 2 , is used to add growing microbes, nutrients including carbon sources, and oxygen after the settling tank, but before the distribution box for efficient nitrification and denitrification of waste.
The distribution box can be made large or small depending on the flow rate of waste water and the rate of addition of components from the apparatus ( 31 ).
FIG. 2A is an expanded view of the apparatus called controller “Tommy Box”, used for the addition of the carbon or electron donor source, nutrient, the biological microbial medium, and air used to accomplish effective aerobic and anaerobic waste water treatment. Growing microbes in bacteria holding tank ( 5 ) are pumped using bacteria pump ( 15 ) controlled by a controller-timer ( 7 ), to the exit point ( 56 ). Nutrient and carbon/electron donor source holding tank ( 6 ) feeds into the carbon/electron donor pump ( 10 ), controlled by the controller-timer ( 7 ), to the exit point ( 56 ). Air pump ( 26 ) controlled by the controller-timer also pumps air to the exit point ( 56 ). The exit point ( 56 ) of the apparatus is placed on line before the distribution box in FIG. 1 . This allows for controlled predetermined feed of air, carbon, nutrients, and bacteria into the waste water flow before the distribution box. The controller timer allows for measured addition of microbes, nutrients, carbon and air. If needed, additional tanks and pumps may be installed in the apparatus for controlled addition of other ingredients for any other specific treatment.
FIG. 2B is another design of the apparatus called controller “Tommy Box”. The timer, the carbon pump, and the bacteria pump, the carbon storage container, and the bacteria storage container are installed inside a box to protect from the elements. Additionally, a small thermostatically controlled heater is provided to keep the box at an optimum temperature for the bacteria and carbon.
FIG. 3 is another embodiment of the invention where waste water flow into settling tank or septic tank ( 1 ), and flows into a distribution box ( 4 ) connected to receive input from Apparatus ( 31 ), which delivers controlled quantities of carbon, nutrient, bacteria, and air. The treated water finally flows into the soil absorption system ( 6 ).
FIG. 4 is a preferred embodiment of the invention where waste water flow into settling tank or septic tank ( 1 ) and flows into a dosing mechanism section ( 2 ). A septic tank 1 , or other form of primary settling tank or unit may be used for initial settling of large solids from the waste water initially transferred from some type of facility, whether a single-family residence, a grouping of buildings, or an industrial facility. The septic tank 1 may be an existing unit, or it may be provided as part of an integrated treatment system of the present invention. The present invention includes a primary treatment unit that is a dosing zone or mechanism, which receives the controlled addition of carbon or electron donor, nutrients, bacteria, oxygen and any other additive, using the apparatus ( 31 ) at the specific location or zone. For aerobic zones oxygen is provided, whereas for anaerobic zones, oxygen is not provided. The output from the apparatus ( 31 ) is preferentially introduced at the input side of the dosing mechanism. In some cases it may be advantageous to introduce the output of the apparatus midway into a zone or close to the bottom of the zone. The dosing mechanism may be replaced by a distribution box for a single-family residence, as shown in FIG. 3 , or could be a dosing tank as described in FIG. 7 . The output can then be further treated by a sand filter or sent to the environment or the soil absorption system.
The treated water that passes through the treatment system is then drawn off or otherwise moved to another site, such as a leach field, a secondary water user, such as a toilet, to a final usable water site, such as via a soak hose system, or it can be discharged to nearby water bodies.
The apparatus (Tommy Box) ( 31 ) introduces controlled quantities of carbon, nutrient, bacteria, and air into the dosing mechanism ( 2 ) section. The waste water then flows through a sand filter ( 3 ). A portion of the treated water may be diverted to the soil absorption system ( 6 ). Another portion of the treated water may be re-circulated using a flow mechanism to the input of the settling tank ( 1 ), and flows into a dosing mechanism section ( 2 ).
FIG. 5 is another embodiment of the invention where waste water flow into settling tank or septic tank ( 1 ) and flows into a reactor ( 9 ). The apparatus (Tommy Box) ( 31 ) introduces controlled quantities of carbon/electron donor, nutrient, bacteria, and air into the input of the reactor vessel ( 9 ). A portion of the treated water may be diverted to the soil absorption system ( 6 ). Another portion of the treated water may be re-circulated using a flow mechanism to the input of the settling tank ( 1 ), and flows into a reactor ( 9 ). The apparatus (Tommy Box) ( 31 ) introduces controlled quantities of carbon, nutrient, bacteria, and air into the input of the reactor vessel ( 9 ). This process is repeated, and gives additional treatment time for the waste water.
FIG. 6 is another embodiment of the invention where waste water flow into settling tank or septic tank ( 1 ) and flows into a dosing tank mechanism section ( 2 ). The apparatus (Tommy Box) ( 31 ) introduces controlled quantities of carbon, nutrient, bacteria, and air into the dosing mechanism ( 2 ) section. The waste water then flows through an aeration structure ( 12 ) and is discharged to the environment. A variation is to treat the output using a sand filter before being discharged to the environment.
FIG. 7 is another embodiment of the invention where waste water flow into settling tank or septic tank ( 1 ), and flows into a dosing tank ( 2 ) connected to receive input from apparatus ( 31 ), (Tommy Box), which delivers controlled quantities of carbon, nutrient, bacteria, and air. The treated water finally flows into a RUKK Filter system ( 13 ), described in U.S. Pat. Nos. 4,465,594 and 5,588,777 (incorporated herein by reference) and finally to the environment.
FIG. 8 is another embodiment of the invention where wastewater is treated using a series of alternating aerobic and anaerobic reactors or zones. The series of alternating aerobic and anaerobic reactors or zones can be any number as desired. At the inlet to one or all of the aerobic zones or reactors, the apparatus 31, “Tommy Box” delivers nitrifying microbes and oxygen. In this zone, ammonia is converted to nitrite and nitrate. If needed, carbon, nutrient or electron donors may also be added, if the waste water is deficient in the above ingredients. Denitrifying microbes, may also be added, if there are zones in the reactors that are anaerobic, and therefore can participate in denitrification, and thereby increase the efficiency of the nitrogen removal process.
At the inlet to one or all of the anaerobic zones or reactors, the apparatus 31 , “Tommy Box” would be set to deliver denitrifying microbes, carbon or electron donor and nutrients. No oxygen is delivered to the anaerobic reactors or zones. The amount of carbon, electron donors, and nutrient added is related to the needs of the system. In this zone denitrification of nitrates and nitrites to nitrogen gas takes place. The discharge from the final anaerobic reactor could then be sent to the environment or for tertiary treatment. U.S. Pat. No. 4,279,753 issued to Nielson et al. describe multiple series of alternating aerobic-anaerobic bioreactors in series can utilize the current invention to improve the efficiency and dependability of such a wastewater treatment system. U.S. Pat. No. 6,235,196 issued to Zhou also describe multiple reactors which can utilize the improvements of the invention.
In FIG. 9 , if only two aerobic and anaerobic zones are needed, then only two apparatuses ( 31 ) feeding the inlets to the aerobic and anaerobic zones would be used. The size of the apparatus could be scaled based on the size of the reactors 90 , 91 , zones and the wastewater flow rates. The discharge from the anaerobic reactor could then be sent to the environment ( 6 ) or for tertiary treatment.
FIG. 10 is a dual spherical reactor vessel embodiment where liquid wastewater flows into a settling tank or septic tank ( 1 ), and flows into a primary spherical reactor vessel ( 102 ) connected to receive input from apparatus ( 31 ), (Tommy Box), which delivers controlled quantities of nutrient, bacteria, and air. The output then flows to a secondary spherical reactor vessel( 103 ) where nutrients and bacteria can be delivered into said vessel near the bottom, middle and top of the fluid. In the preferred example the reactor vessels should hold between 2 and 8 days of retained daily flow volume. The output of the secondary reactor vessel leads to the soil absorption system( 6 ).
FIG. 11 is another embodiment of the invention wherein wastewater is treated using a single reactor ( 110 ) which contains both an aerobic( 95 ) and an anaerobic( 96 ) zone. The two zones may be separated by some mechanical means, or may be a two fluid regions not separated by mechanical means. At the inlet to the aerobic zone the apparatus ( 31 ), “Tommy Box” delivers nitrifying microbes and oxygen. If needed, carbon, nutrient or electron donors may also be added, if the waste water is deficient in the above ingredients. In this zone, ammonia is converted to nitrite and nitrate.
At the beginning of the anaerobic zone ( 96 ) where the two zones meet, a second apparatus 31 , “Tommy Box” would be set to deliver denitrifying microbes, carbon or electron donor and nutrients using transfer means ( 97 ), which could be a tube. No oxygen is delivered to the anaerobic zone. The amount of carbon, electron donors, and nutrient added is related to the needs of the system. In this zone denitrification of nitrate and nitrites to nitrogen gas takes place. U.S. Pat. No. 6,086,765 issued to Edwards, describe a single aerobic-anaerobic reactor that can utilize the current invention to improve the efficiency and dependability of such a wastewater treatment system.
FIG. 12 shows the Oxic and Anoxic reactor with Apparatus (“Tommy Box”) with lines for the introduction of bacteria, carbon and air, the use of a heating means to heat the aerobic zone, and the use of filters in the fluid exit from the aerobic and anaerobic zones. Optional heating means may be introduced to the anoxic zone. Optionally, an additional reactor or zone may be added where the effluent leaving the anaerobic reactor or zone is aerobically treated with air to reduce the BOD before it is released to the soil absorption system or environment. Optional tanks for additional aeration, filtration by sand filter or other soil absorption system, ultraviolet treatment, ozone treatment and membrane filtration are not drawn.
In the aerobic and anaerobic zones a membrane filter (hollow fiber or other) may be used to remove effluent by filtration. The membrane prevents the loss of microbes from the anoxic reactor.
FIGS. 13A and 13B . Embodiment of the invention for a filter system. The system includes a holding tank 10 having an outlet 14 that draws nitrifying bacteria (from transfer apparatus)leading to a leaching field 16 . A porous bed of sand or fine gravel is provided below the leaching field 16 , and includes an in-drain 18 having a core 20 surrounded by an outer envelope 22 of geotextile fabric material. Conduit means 24 having a lower branch 24 a that draws denitrifying bacteria (from transfer apparatus) is provided. The upper end of the conduit means 24 communicates with pump 26 that draws liguid carbon from a reservoir 28 in response to the output of a timer 30 .
FIG. 14A . Embodiment of the invention for a modified nitrification denitrification filter system.
FIG. 14B . Improved embodiment of the invention for a modified nitrification denitrification filter system.
FIG. 15 . Another layout for the apparatus for 1 liter reactors.
FIG. 16 . Layout for Apparatus shown for 1 liter reactors with fixed media in the oxic and anoxic reactors.
FIG. 17 . Comparison of the performance of the Mini OAR 1 (Fixed Film Media) and Mini OAR 2 for combined nitrogen, under different operating conditions.
FIG. 18 . Another embodiment of the controller, where the layout of the different components are shown. The bacteria pump, the carbon pump and the air pump are controlled by a timer/controller. The controllers may be optionally connected to a master controller for external remote control by a computer. The master controller can also receive inputs from sensors in the OAR system to monitor temperature, flow rates, ammonia, oxygen, nitrate and bacteria. These inputs may be programmed using a controller to reset the pumping rates for bacteria, carbon and air.
EXAMPLE 1
Preparation of Nitrification and Denitrification Bacteria Mixture
Bacteria mixtures useful in nitrification and denitrification were prepared by mixing bacterial mixtures containing various bacterial strains known to nitrify and denitrify.
For nitrification, a mixture of Enterobacter Sakazaki (ATCC 29544), Bacillus coagulans (ATCC7050), Bacillus subtillis (ATCC 6051), Bacillus subtillis (ATCC 6051), Bacillus megatarium (ATCC7052), Bacillus licheniformis (ATCC14580), Bacillus cerus (ATCC4513) and Bacillus pasytereurii (ATCC 11859) was used. For nitrification, the bacteria were not easy to identify, and include Nitrobacter and Nitrocococcus spp obtained from Cape Cod Biochemicals, 21 Commerce Road, Bourne, Mass.
Bacterial growth media was prepared in 1 liter batches by dissolving 20 g Bacto Tryptose, 2 g Bacto Dextrose,(Difco Laboratories, Detroit, Mich.), 5 g sodium chloride, and 2.5 g disodium phosphate (Sigma-Aldrich Corp., St. Louis, Mo., USA) in 1 liter of deionized water, and sterilizing at 25° F. for 15 minutes in an autocloave. The bacteria, 0.1 ml, if in liquid form, and 0.5 g, if in dry form, was added to 100 ml of media prepared above, and grown at 37° C. for 3 days. At the end of 3 days, 100 ml of the grown bacteria were added to 4 liters of growth media, and grown for 3 days before use. The bacterial mixtures were then used in field testing.
EXAMPLE 2
Preparation of Carbon Nutrient Mixtures
Carbon mixtures that are non-flammable, have low viscosity and are readily pumpable liquids, and stable to premature microbial growth were prepared by adding to 100 ml of deionized water, 50 g Maltrin M250 (Grain Processing Corporation, Muscatine, Iowa, USA), dissolving the solids, and adding 10 ml of methanol (Sigma-Aldrich). In addition to the carbon sources, other micronutrients generally used for growth of bacteria, and described in Handbook of Microbiological Media by R. N. Atlas, CRC Press, Cleveland, Ohio and Media Formulations described in the ATCC catalog, ATCC 12301 Park Lane Drive, Rockville, Md., were added in the generally recommended quantities. The carbon and nutrient mixtures were found to be stable, as measured by unwanted premature growth for over 4 weeks.
The bacterial mixtures and carbon/nutrient mixtures were tested for viability using solutions made up of ammonium chloride for ammonia conversion, and sodium nitrate for nitrate conversion. The nitrifying and denitrifying bacteria were found to be effective for conversion of ammonia and nitrate, respectively.
Ammonia was measured using a Hanna Instruments Inc, 584 Park East Drive, Woonsocket, R.I. 02895, High Range Ammonia Calorimeter, Catalog No, HI 93733, and the ammonia testing reagents kits. Nitrate was measured using a Hanna Instruments Inc., 584 Park East Drive, Woonsocket, R.I. 02895, Nitrate Calorimeter, Catalog No. HI93728, and the nitrate testing reagents kit.
The nutrient carbon mixtures were scaled up to 10 gallons, by dissolving 42 pounds of Maltin M250 in 10 gallons of deionized water using a paddle, and adding 3,785 ml of methanol (Doe and Ingals, Medford, Mass.). In addition, other micronutrients generally used for growth of bacteria described in Handbook of Microbiological Media by R.N. Atlas, CRC Press, Cleveland, Ohio and Media Formulations described in the ATCC catalog , ATCC 12301 Park Lane Drive, Rockville, Md. were added in the recommended quantities. In addition to deionized water, tap water also may be used. The carbon nutrient mixtures prepared above were used in the field testing described below.
Leaching Field Test
EXAMPLE 3
The bacterial and carbon/nutrient mixtures were then tested in a field test in a system as described in FIG. 2 and FIG. 3 , in a sewage treatment testing facility. The waste water exiting the settling tank had 36 ppm nitrate, and was flowing at a rate of 78 gallons/day, and the septic/settling tank was 1500 gallons. The bacteria mixture of nitrifiers and denitrifiers was fed at a rate of 11 ml/hr for 1 hour, each 6 hours, 4 times/day. The carbon/nutrient was added at a rate of 110 ml/hr, for 1 hr every 4 hours, for a total of 660 ml/day. Samples were taken after 14 days under the leaching field at a depth of 1 ft, and 2 ft and tested for nitrate nitrogen. The results are given in Table 1.
TABLE 1
FIG. 2 Field Testing of Waste Water
Nitrate
nitrogen, ppm
Before treatment
1
ft
2
ft
under the leaching field
29–37
ppm
29–37
ppm
With treatment as in FIG. 2
1
ft
2
ft
under the leaching field
10
ppm
2
ppm
Ammonia was measured using a Hanna Instruments Inc, 584 Park East Drive, Woonsocket, R.I. 02895, High Range Ammonia Calorimeter, Catalog No, HI 93733, and the ammonia testing reagents kits. Nitrate was measured using a Hanna Instruments Inc, 584 Park East Drive, Woonsocket, R.I. 02895, Nitrate Calorimeter, Catalog No, HI93728, and the nitrate testing reagents kit.
Reactor System Test
EXAMPLE 4
The bacterial and nutrient mixtures described in examples 2 and 3 were then tested in a field test in a system as described in FIG. 5 in a sewage treatment system facility. The discharge from the treatment system reactor system had Total Nitrogen (TN) in the range 91–135 ppm, prior to the field test, and not discharging final concentrations of TKN generally required for discharge limits in waste water treatment facilities. The waste water exiting the septic/settling tank had about 91–135 ppm TN and was flowing at a rate of about 3,500 gallons/day, and the septic tank was about 5000 gallons. The reactor vessel was about 5000 gallons. The bacteria mixture, containing denitrifiers and nitrifiers capable of converting ammonia to nitrate and nitrite, and further nitrate and nitrite to nitrogen, was added continuously at the entrance to the reactor vessel at a rate of 1 liter/day for 1 week. At the end of one week, the bacterial addition was changed to 250 ml/day. Samples were taken 12 and 19 days after the initial addition of the bacteria at the point of discharge, and tested for TN by an outside water testing laboratory. The results are given in Table 2.
TABLE 2 Reactor System (FIG. 5) Field Testing of Waste Water TN, Before treatment 91–135 ppm In the discharge With treatment as in FIG. 5 12 days 19 days In the discharge 31 ppm 4–6 ppm
Sludge Reduction
EXAMPLE 5
The reactor described in example 4, which was approximately 8 feet by 8 feet by 8 feet before the treatment with the bacterial mixture had sludge to a height of about 4 feet. The sludge in the reactor when measured at the end of about 90 days was approximately 1 foot.
EXAMPLE 6
Dual reactors as shown in FIG. 10 could be used for nitrification and denitrification by fermentation of waste water. Waste flow enters a 1,500 gallon settling tank that has a “T” at the effluent end that leads to a 750 gallon plastic sphere (Zabel Environmental Technology, PO Box 1520, Crestwood, Ky., 40014). House wastewater enters the settling tank in a range of 80–200 gallons per day. Settled fluid enters the primary reactor where nitrifying bacteria as described in example 3 are introduced into the system using the apparatus “Tommy Box” as shown in FIG. 10 . Nutrients could be added to primary reactor to stabilize the pH and micro nutrient levels. In addition to bacteria and nutrients, optionally air may be used to aerate the system.
The aerated effluent from the primary reactor flows into the secondary reactor. The secondary 750 gallon Zabel spherical reactor receives denitrifying bacteria and carbon as described in example 3. The carbon and bacteria are added into the system on or near the bottom where little or no oxygen is available. The output of the secondary reactor flows directly into the soil absorption system.
EXAMPLE 7
The Oxic Anoxic Reactor (OAR)system as shown in FIG. 12 was installed at the Massachusetts Alternative Septic Test Center, Otis Mass. This is a variation of FIG. 9 , where two apparatuses are shown. Extra pumps as needed may be installed inside the apparatus(“Tommy Box”)for delivering two or more different mixtures of bacteria to specified locations in the OAR system. A larger air aerator and diffuser capable of producing oxygen concentrations in the 3 to 8 mg/liter was used. These dual tank stepwise multi tank systems are used for reducing TSS, COD, phosphate, nitrification and denitrification of the wastewater.
The OAR system is a gravity fed continuous reactor where primary effluent first enters a settling tank (Massachusetts Title V or equivalent regulations). Flow rates entering the tank ranged from 100–550 gallons per day. Over one year the influent temperature and oxygen levels ranged 2 to 28 degrees Celsius, and 0.0–0.5 mg/l respectively. The second stage flows into the first OAR tank, aerobic reactor, (T 1 ) where temperature and oxygen are monitored by sensors. The sensor information is used to control the temperature and oxic conditions. The air is purged into T 1 using a diffuser for better aeration. The need for bacteria is also monitored and added as needed. Residence time or dwell in T 1 is designed to average about 1–6 or more days depending on the level of nitrification needed. Oxygen concentration and temperature are held between 3.0–8.0 mg/l and about 20–40 degrees Celsius respectively, by means of an aerator and a heating means inserted into the tank T 1 . The preferred temperature is 24 degrees Celsius. The heating means may be by electrical heating or solar heating with temperature controls. Growing nitrifying bacteria and denitrifying bacteria are introduced at a rate of 1 to 10 ml per 100 gallons of raw effluent flow. Bacterial concentrations ranged from 10 exponent 12 to 10 exponent 17 cells per ml. Nitrified effluent passes through T 1 into an optional filter and into Tank 2 (T 2 ). T 2 contains injection ports to deliver the non-flammable carbon source of the invention, as well as nitrifying bacteria from the apparatus. While other sources of carbon may be used, it is preferable to use the non-flammable liquid carbon source of the invention as the bacteria have been specifically grown in that carbon source, and the carbon source contains the preferred nutrients for the optimum performance of the bacteria. The carbon pump is set to deliver carbon at a rate sufficient to decrease the nitrogen level desired by the local wastewater regulations. Generally for 1 mg of nitrogen, 1–4 mg of carbon would be needed for bringing the level of nitrogen to below 10 mg/l, depending on the content of carbon present in the nitrified wastewater. The wastewater flow rate and the concentration of nitrogen in the influent dictate the flow rate and volume of carbon to be delivered. The outlet of the tank T 1 can have an optional filter for removing particulates and any large media particles or suspended media introduced. T 1 can also contain fixed film media if desired. The oxygen level in T 2 rapidly approached near undetectable values from top to bottom of the tank for anoxic conditions. Residence time is designed to average 1–4 days, preferably 2 to 3 days. Denitrifying bacteria that had been previously added in T 1 where they begin their initial growth under aerobic conditions can migrate to T 2 and continue the denitrification under anoxic conditions. Optionally, denitrifying bacteria can be added to T 2 as needed for denitrification. The OAR system allows the separation of various microbiological functions to enable complete system control and testing capabilities. Optionally, a filter is placed at the end of the tank T 2 for particulate removal as well as for holding any suspended media introduced to the system for bacteria growing on surfaces. Fixed film media may also be introduced into T 2 as desired. Optionally, a membrane filter, such as a hollow fiber or flat sheet membrane may be used to filter the effluent, by applying a vacuum to the lumen side, leaving the bacteria in the tank T 2 . The effluent finally travels to a distribution box where it is distributed to a soil absorption system such as a leaching field. The effluent may also be directed to a sand filter or modified sand filter for additional removal of suspended solids, bacteria, and in addition can be treated using ultraviolet light, ozone or chlorine to provide tertiary treated water or recycled water, and further treated by reverse osmosis as needed. The tanks T 1 and T 2 are placed in the ground such that T 1 is at a lower level compared to the settling tank outflow, and T 2 is at a lower level relative to T 1 so that there is gravity flow. This avoids the need for pumping of wastewater required in many commercial systems and is energetically favourable.
The OAR system was started on day 1 receiving 150 gal/day with influent from a trench that was fed from a septic tank. Influent levels were for Ammonia of about 35 mg/l, Nitrate close to 0 mg/l, Oxygen close to 0 mg/l, Total Suspended Solids(TSS) in the range 150–230 mg/l, Chemical and Biological Oxygen Demand (CBOD), in the range 235–339 mg/ml. On day 17, the OAR effluent exciting from T 2 had TSS<30 mg/l, CBOD<20 mg/l, Total Nitrogen (Ammonia plus Nitrate) was generally below 10 mg/l. Sample measurements for each data point were taken 3 times a week.
For the oxic and anoxic reactors, additional mixing means such as stirrers and mixes can be added to improve the performance of the system, and keep especially suspended fixed film media in suspension. In addition, if activated sludge is used, the controlled addition of bacteria can improve the performance of the activated sludge system over and above its normal performance.
EXAMPLE 8
FIG. 13 shows the use of the invention to improve the performance of U.S. Pat. No. 5,588,777 incorporated herein by reference. The apparatus(not shown) introduces nitrifying bacteria after the septic tank, so that the bacteria are dispersed in the sand filter. Optionally denitrifying bacteria may also be introduced and additional aeration provided.
Instead of the liquid soap, the non-flammable carbon source can be used. Denitrifiers may also be added in the anoxic bottom zone of the filter.
EXAMPLE 9
FIG. 14A shows the use of the invention to improve the performance of U.S. Pat. No. 4,465,594 incorporated by reference. The apparatus(not shown) introduces nitrifying bacteria after the septic tank to the holding tank ( 10 ), so that the bacteria are dispersed in the (aerobic) nitrification filter( 12 ). An optional mixing tank may be provided between the nitrification filter and the holding tank for receiving the nitrifying bacteria. This holding tank is optionally heated to between 10 and 35 degrees Celsius for improved nitrification. The heated nitrified effluent is collected in the chamber 18 . Denitrifying bacteria is introduced to chamber ( 18 ) along with non-explosive carbon described in this invention. The chamber can optionally have mixing means for better dispersion of denitrifying bacteria and carbon. The bacteria and carbon flows to the anoxic detention tanks where denitrification takes place.
EXAMPLE 10
FIG. 14B is another embodiment of the invention where the apparatus is used to introduce nitrifying bacteria into a pump chamber before the nitrification filter. optionally, the pump chamber may also be aerated for efficient nitrification in addition to that provided by the air vent. Furthermore, the pump chamber may be heated to maintain a temperature of between 10 and 35 degrees Celsius for efficient nitrification. The apparatus is used to introduce denitrifying bacteria and a carbon source into the mixing chamber. The use of the denitrifying bacteria grown with the non-flammable carbon source is preferred.
EXAMPLE 11
The effluent from the septic tanks (the primary treatment) were tested using a scaled down version of the Oxic Anoxic Reactor(OAR) scaled down to 1 liter, with and without a fixed film media. The effluent from the sepic tank is the same effluent used in example 7, and had combined nitrogen in the 35 mg/l range. The fixed film media used was a fibrous filter used for air filtration produced by Flanders Precision Aire, St. Petersburg, Fla. FIGS. 15 and 16 show different layout for the apparatus to be used with the OAR system. Air was introduced to the aerobic reactors in FIG. 15 (Mini OAR 1) and 16 (Mini OAR 2). The flow rate of the effluent entering the aerobic tank was between 100–300 ml/day. Growing nitrifying bacteria was added to the aerobic reactor at the rate of 1 ml/day, once a day because of the small volume. The liquid carbon was added at the rate of 0.1 ml/day, once a day. The temperature of this system was kept at room temperature of between 16 to 20 degrees Celsius.
FIG. 17 gives the combined nitrogen data under various conditions. From Jun. 17, 2002 to Jul. 3, 2002 growing bacteria and liquid carbon were added as described above. The combined nitrogen stayed below 12 mg/l during this period. On Jul. 3, 2002, the addition of growing bacteria and liquid carbon was stopped, and resulted in an increase of the combined nitrogen to between 20 and 30 mg/l. On Jul. 10, 2002, the addition of bacteria and carbon was resumed. Within one week, the combined nitrogen in both OAR systems was below 10 mg/l and trending towards the values before the disruption in the addition of bacteria and carbon. Use of a suspended film media is expected to produce a similar result.
EXAMPLE 12
Power Failure Stress Test
Power shut off stress test of the 220 gallon per day OAR (Oxic Anoxic Reactors) as shown in FIG. 12 was carried out as follows. The OAR installed at the Massachusetts Alternative Septic Test Center, Otis Mass. Nitrification and denitrification of the waste water was monitored to determine the effects of 4 days of complete power shut down. During 4 days from May 24 to May 28, 2002 all electrical power was shut off on the OAR System. Effluent continued to be sent into the system. Throughout the 4-day period air, carbon, heat and bacteria were not functional. Total Nitrogen (Ammonia and Nitrate) during the shut off the system was still below 20 mg/liter. Three days after restoring power the Total Nitrogen began to drop back to below 10 mg/liter in 7 days.
EXAMPLE 13
Stability of nonflammable liquid carbon to microbial stability was tested. Non-flammable liquid carbon was made by dissolving 1000 ml of deionized water 500 g of Maltrin M250 and micronutrients described in example 2 without methanol. The liquid carbon solution was divided into 5 aliquots of 100 ml. each by transferring into 100 ml sterile glass bottles baked at 250 degrees Celsius. One bottle was kept as a control. To the second bottle 5 ml methanol was added to bring the methanol concentration to 5%. To the third 5 ml of formalin (10% formaldehyde solution) was added to bring the formalin. concentration to 5% of the added formalin. To the fourth 2 ml of Iodopropynyl Bulycarbamate(Germal) was added to bring the Iodopropynyl Bulycarbamate concentration to 2%. To the fourth bottle 10 ml sodium hypochlorite solution (Americas Choice Bleach Compass Foods, Modale N.J. USA) was added to bring the added bleach concentration to 10%. To the fifth bottle 3 ml 1M sodium hydroxide was added to bring the pH of the solution to 12.6. Each bottle was then spiked with 0.1 ml of bacteria cultures grown for 4 days on Difco TPD Media. The samples were stored at 18 to 20 degrees Celsius for one week and observed daily.
The control liquid carbon carbohydrate solution with no additive was cloudy with stringy mass and pale yellow color. The methanol, formalin and Germal were all clear with pale yellow color, the bleach was clear with no color, and the bottle with sodium hydroxide was clear with dark yellow color. The control showed rapid growth in less than 2 days, whereas none of the others showed any growth.
In addition to the use of nitrifying and denitrifying bacteria, a wide variety bacteria and bacterial mixtures can be used to modify or remove a many pollutants, contaminants from many sources. Several of the bacteria mixtures are available commercially, such as from Bio-Systems Corporation, 1238 Inman Parkway, Beloit, Wis. 53511, and incorporated by reference. The bacteria may treat municipal, industrial, commercial, and residential waste. Some of these users are for degradation of complex chemicals such as phenols, benzene compounds, surfactants, alcohols, aliphatic compounds, aromatic compounds, and other ionic waste such as chlorates, perchlorates, cyanides, nitrites, nitrates or any other pollutant that can be reacted and removed by bacteria. Other users for contaminant and pollutant control and removal are in chemical waste, grease removal, grease control, chlorinated organics, dairy waste, refinery waste, hydrocarbon soil remediation, marine pollutant control, hydrocarbon oil sump treatment, municipal activated sludge, fish farming, pulp and paper bio-augmentation, municipal lagoons, manure waste, portable toilet treatments, drain and grease traps, odor control, and septic tank treatments. Additional potential uses are in aquaculture, aquariums, food waste and grease traps, pond reclamation and farm waste remediation.
The invention is equally applicable to any wastewater system that suffers from frequent failure, and that has separate oxic, aerobic, anoxic and anaerobic regions. This invention can be used with recirculating sand filters, trickling filters, and any aerobic and anaerobic treatment systems. The applicability of this invention is not restricted to nitrification and denitrification, and equally applicable to other pollutants which can be microbiologically treated. | Method and apparatus for treating contaminants in water under anaerobic conditions is disclosed. The method includes adding to contaminated water a composition including an aqueous mixture of at least one carbohydrate and at least one alcohol and/or bacteriastat. The apparatus includes a source of growing nitrifying bacteria effective for treating contaminants under aerobic conditions, a source of growing bacteria effective for denitrification under anaerobic conditions, and a controller for introducing the growing bacteria in a predetermined amount over a predetermined period of time. | 8 |
This application is a continuation in part of application Ser. No. 301,592, filed Sept. 14, 1981, now abandoned.
FIELD OF THE INVENTION
The present invention relates generally to semiconductor devices, and more particularly to methods and apparatus for identifying processing and test details in semiconductors.
BACKGROUND OF THE INVENTION
In the field of electronics, it has long been desirable to be able to identify pertinent processing and test information about particular semiconductor circuits or chips. In some instances, reworked parts are not satisfactory for a customer's use. In memory arrays implemented with redundancy, some customers desire to know whether and where redundancy was used because of pattern sensitivity and other considerations. For some applications, particularly where military or other specialized specifications are to be met, it is useful to know whether certain visual inspections or tests have been performed on the part, or what the results are of critical dimension measurements, such as layer thickness, or other parameter measurements made during the processing of the lot of wafers from which the part is made. However, prior to the present invention, obtaining pertinent and useful processing and test details, such as wafer number, lot number, processing parameters, special visual and test results and manufacturing network data has been difficult if not impossible to obtain because after processing, testing and packaging it is difficult to keep track of particular manufacturing lots in inventory, and records are often fragmented or nonexistent.
Inspections of the package do not directly reveal this information, and are frequently complicated by the presence of adjacent circuitry, lack of identifying marks on the package, coatings or other coverings placed over the chip to assure circuit integrity and other reasons. Even where helpful information such as assembly date is provided on the package, the underlying wafer processing records are often unlocatable, inaccurate or incomplete. Inspections of the chip itself are difficult because of all of the foregoing and most often do not reveal pertinent information. In any event, the package is not intended to be removable, and such removal normally destroys the device.
As a result, there has been a need for a method and device whereby processing and test information could be determined with certainty without the need for reliance on incomplete or difficult to trace paperwork.
SUMMARY OF THE INVENTION
The present invention provides an inexpensive and reliable solution to the foregoing problem, whereby substantial amounts of processing and test information regarding the actual part under consideration may be ascertained by electrically interrogating the semiconductor chip, More specifically, programmable memory cells into which the desired processing and test information can be placed prior to final sort of shipment to a customer are placed on the semiconductor chip adjacent that portion of the chip which performs the primary function of that circuit.
An enable/disable circuit is also included on the chip and serves to disconnect the added memory cells from the primary circuit during normal operation. Similarly, when the user desires to determine the information stored in the memory cells, a signal is provided to the enable/disable circuit which disconnects the primary circuit and permits access to the memory cells containing the desired information. In this manner the product information memory may be electrically connected to the same pins on the chip which provide electrical connection to the primary circuit.
It is one object of the present invention to provide an improved method of providing processing and test information for semiconductor circuits.
It is another object of the present invention to provide an improved, inexpensive and reliable device for providing key processing and test parameters of semiconductor circuits to the user.
It is still another object of the present invention to provide a device and method which permits a user to ascertain processing and test information of semiconductor circuits without need for visual inspection of the chip or resort to examination of processing documents.
It is yet another object of the invention to provide a device and method whereby processing and test for semiconductor circuits can be ascertained through electrical interrogation of the circuit.
These and other objects of the present invention can be better appreciated from the following detailed description of the invention, taken with reference to the appended figures, in which
FIG. 1 is a schematic block diagram showing the present invention implemented on an exemplary semiconductor circuit such as a byte-wide memory,
FIG. 2 is a schematic representation of an enable/disable circuit suitable for use with the present invention,
FIG. 3 is a more detailed logic diagram of an enable/disable circuit suitable for use with the present invention, and
FIG. 4 is an exemplary table of typical processing and test information with a suggested format for encoding such information.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, there is shown therein an exemplary semiconductor primary circuit 10 with which the present invention can be effectively used. More particularly, the primary circuit 10 may be a device such as an electrically erasable, programmable, read only memory (EEPROM) such as manufactured by a number of semiconductor vendors. The EEPROM may be a 16K device, storing 16K bits of binary information, arranged in a 128-by-128 bit array 12. Thus, each row and each column contains 128 bits of information. As with many other memory devices, that information is organized into groups of bits, referred to as bytes, and simultaneous access is provided to those bits which comprise a selected byte of information. A byte typically comprises eight bits, and this format will be used for purposes of discussion of the present invention herein.
The access to the memory array referred to above is provided through column decoder 14, row decoder 16 and column address gating 18, with the output from the array being presented via an output buffer 20. The column decoder 14 and row decoder 16 are controlled by signals provided to their inputs via address pins A0 through A3 and A4 through A10, respectively. The output of the memory array 12 appears on output pins Q1 through Q8.
In accordance with the present invention, the memory array 12 has been modified to include a processing and test information array 30. The information array 30 is, for the exemplary device shown here, preferably arranged in the format of a single column, to permit serial access to processing and test information stored in array 30, which is configured as a 128×1 bit array. However, it is also possible to incorporate the array 30 in the form of a plurality of columns, or in the form of one or more rows. Those skilled in the art will recognize how to implement such embodiments from the disclosure herein.
The array 30 is preferably a non-volatile memory of the EEPROM type, especially where the primary circuit 10 is a memory device such as an EEPROM or EPROM, since the same processing steps used to fabricate the primary circuit can be used to fabricate the array 30. It must be noted, however, that where the primary circuit is an EPROM erasable by ultraviolet light, EEPROMs or other similar types of non-volatile memory elements cannot be used for array 30 since the information placed in array 30 should not be subject to erasure. In addition, where the primary circuit is very different from the EEPROM or EPROM structures, the extra processing required to fabricate array 30 from these devices makes their use impractical, and other means must be used. In such instances, the present invention may employ other types of memory elements, such as fusible-link devices or laser-blown fuses as are known in the art, for the array 30. Of these, the laser type elements are preferable since they occupy less chip real estate than do fusible-link arrays.
It is neccesary that the data stored in the product information array 30 not interfere with the normal operation of the primary circuit on the chip; i.e., the memory array 12 and associated decoders, gates and buffers. To ensure that undesirable interference does not occur, while at the same time permitting the existing pins to serve dual functions to access the memory array 12 and the information array 30 at the appropriate times, multiple level signals are applied to a selected column address pin. For purposes of this discussion, in which a 16K EEPROM device is exemplary, column address pin A1, indicated as line 32, has been selected to operate with dual functions. When the primary circuit 10 is other than a memory array, any pin may be selected which has access to a convenient location on the die for the array 30.
For conventional operation, conventional TTL signal levels are applied to line 32. However, to access the information array 30, a high voltage signal such as fifteen volts is impressed upon the line 32. To permit the circuitry to distinguish between the conventional TTL signals and the high voltage signal, array access logic 34 is provided as an interface between a column address pin A1 and the column decoder 14 and array 30. The line 32 is thus connected to the access logic 34, which detemines whether a high voltage signal is present.
If the signal on the line 32 is of conventional levels, access to the information array 30 is disabled by means of a signal on a line 36, and the column decoders 14 are conversely enabled thereby. The signal impressed on the line 32 is also supplied to the column decoders 14 on a line 38. However, should the signal on the line 32 be high voltage such as fifteen volts, the logic 34 detects the high signal, disables the column decoder 14, and at the same time addresses the array 30 via line 36. Then, by conventional exercising of the address lines A4 through A10, serial access to the 128 bits of information stored in the array 30 is provided at its output line 40. The information appears in a conventional manner on one of the output pins Q1 through Q8. Array access logic 34 controls output buffers 20 via line 36 as well as array 30. When array access logic 34 has selected array 30, output buffers 20 pass the output line 40 of array 30 through to one of Q1 through Q8. In FIG. 1, output Q8 is shown connected to array 30 via the dotted line extension of line 40.
Referring next to FIG. 2, the array access logic 34 is shown in more detail and can be seen to include a high voltage detection circuit 102 and a conventional single bit column address buffer 104 (only one of n shown). The buffer 104 is provided to convert the TTL input signals to MOS logic levels and provides both true and complement outputs to the column decoder 14. The high voltage detection circuit 102 provides an enable/disable signal on the line 38, as shown generally in FIG. 1.
Referring further to FIG. 3, the high voltage detection circuit 102 may be comprised of a string of four inverters 202a through 202d, with the inverter 202a having a suitable threshold for detection of the high voltage signal involved. The signal is then restored to conventional TTL levels through the remaining inverters, such that the output of the inverter 202d may be supplied on the line 38 as a conventional TTL signal to the NOR gates 204 (only one shown) which form the input stage of the column decoder 14. In this manner, the high voltage signal on the line 32 can be seen to cause the column decoder 14 to be disabled from conventional operation, while also addressing the information array 30 to provide the desired process and test information.
It will be appreciated that where the primary circuit is something other than a memory array, such as an operational amplifier, line 32 will not be an address line, and in fact may not be a logic level line at all. In such cases, a spare, normally unused pin on the exterior package may be used to select and deselect array 30 by selectively tying it to ground or to a preselected voltage. If a spare pin is unavailable, line 32 must be carefully selected to prevent selection of array 30 inadvertently by choosing a pin whose normal function could cause the pre-selected array access logic threshold voltage to appear on it.
Where primary circuit 10 is a circuit other than a programmable memory array, no address or programming lines exist. Therefore, array access logic 32, in addition to disabling primary circuit 10, must cause several pins to the exterior package of the product to function as address lines, programming lines, and an output line for array 30 and disconnect such pins from the primary circuit 10. Seven address lines will be needed to address array 30 if it is configured as a 128×1 bit array. The choice of which pins to use will depend on the chip, and similar considerations, and is a matter of design choice to one skilled in the art.
Programming of the array 30 may be understood by again referring to FIG. 1. Where line 38 has been impressed with high voltage to enable array 30 and disable primary circuit 10, and control lines 42 of memory array 12 are properly exercised, as is known in the art, programming of array 30 is accomplished.
Line 36 from array access logic 34 disables all of the outputs except Q8, which it causes to be connected to the output of array 30. In addition, line 36 disables all of the write circuitry associated with Q1 through Q7 of memory array 12 so that only array 30 is programmed. In the preferred embodiment, array 30 is programmed one bit at a time under the control of address lines A4 through A10 and control lines 42 in the usual manner.
It is possible to configure another one of address lines A0, A2 or A3 to enable the writing into array 30 by disabling the write circuitry of memory array 12 associated with Q1 through Q7. A means similar in function to array access logic 34 must be provided to sense high voltage on the selected line and perform this function. Use of this extra line is purely a design choice dictated by the needs of the designer.
As previously noted, array 30 may also consist of fusible-links or laser-blown fuses, keeping in mind that the latter must be fully programmed before the chip is encapsulated and thus may not be able to contain data relative to testing done after encapsulation. Connections for addressing, programming and read-out may be provided by array access circuits 32. Addressing, programming and reading these types of memory devices are all well known in the art, and thus implementation of this invention using such memory schemes will be apparent to those skilled in the art, but generally follows the same scheme as disclosed for the embodiment of FIG. 1.
With reference to FIG. 4, an exemplary format for the information in array 30 is illustrated. In a preferred embodiment, array 30 is arranged as a 128×1 bit array, and the information is thus serially accessed. It is to be noted that the information disclosed as contained in array 30 is for purposes of illustration only, and the present invention is by no means limited to arrays containing this information. Differing requirements will necessarily dictate that different information be placed in array 30.
The type of information which typically will be useful to users and manufacturers of semiconductors includes lot number, wafer number, certain process paramenter data, such as layer thicknesses, assembly data, test data, and data specified by customers for their purposes such as user tracking data for maintenance purposes.
FIG. 4 sets out in table form the data and number of bits for inclusion in a typical array 30. First, ten bits are allocated as a pre-code, which may define the meanings of the bits to follow, in order to provide security for the information contained in array 30. This is useful where the data in array 30 may be sensitive and it is desired to prevent competitors or other unauthorized persons from comprehending the data stored in array 30. The meaning and order of these bits is strictly a matter of design choice.
Fourteen bits are allocated as identification of wafer lot number. Up to 16,384 lot numbers may be identified. Six bits are allocated to identify wafer number, allowing up to 64 wafers to be identified.
Ten bits are assigned to provide yes/no information regarding whether certain tests, such as visual inspection, have been performed, or the metallization has been reworked, etc.
Three bits may be assigned to set forth one of eight ranges for measured thickness or width, such as for polysilicon or oxide layers.
Two groups of six bits and seven bits may be used to identify the work week and year for assembly date and test date.
Of the 128 bits available in array 30, FIG. 4 identifies 69. The other 59 bits may be assigned for customer-supplied or customer specified data to fill particular customer needs. This array size appears to be sufficient to accommodate all information required for most applications, although those skilled in the art will recognize that a larger or smaller array may be used at a cost of more or less chip real estate.
As noted previously, the present invention is particularly applicable to byte-wide memories such as RAMs, EPROMs and EEPROMs, and is preferably implemented in a single column format. However, those skilled in the art, given the teachings herein, will appreciate that the present invention could easily be implemented as a row of cells or several rows of cells. In such an instance, a row address would be selected as the address for the array 30, and the information stored in the array 30 would be read out in parallel fashion by conventional exercising of the column decoders 16.
It will likewise be appreciated that, while the present invention is particularly useful on devices of large die sizes, since little additional real estate is required, the present invention is also useful in ensuring consistency for circuits of smaller die sizes. Thus, for example, in some instances semiconductor users have applications where variations or reworks in processing parameters and related characteristics may have substantial impact upon the suitability of the component for the user's task. However, prior to the present invention, reporting of such changes to the user has not always been complete. With the present invention, such changes may be more readily reported since the information array 30 is programmed at the end of processing and testing and is resident on the device. Thus, where reporting of such processing changes is important, the present invention is also useful with small devices.
Although the pins selected for accessing the array 30 of the exemplary device described in detail above were also conventional input and output pins, other pins may also be suitable for such dual functioning. Thus, any pin whose primary function is such that it need not function at the voltage levels chosen for the selection of the array 30 is suitable, subject to the geometries of the die. Likewise any pins which may receive information from the array 30 without adversely affecting the operation of the primary circuit are suitable for use as output pins for the array 30. While an especially high voltage has been discussed as exemplary for selecting the array 30, it will be appreciated that any other signal which is sufficiently outside the normal range of operating voltages for the primary circuit will be acceptable.
While the foregoing has described in detail one embodiment of the present invention, it will be appreciated that, given the teachings herein, numerous equivalents and alternatives which do not depart from the invention will be apparent to those skilled in the art, and those alternatives and equivalents are intended to be encompassed within the scope of the appended claims. | A method and system for encoding key process and test information in semiconductors is disclosed. The invention is particularly useful in connection with byte-wide memories, but also finds application in a wide range of semiconductor devices. A plurality of programmable memory cells are juxtaposed on a semiconductor die with the circuitry which performs the primary function of the chip. The programmable memory cells are interconnected with the primary circuit in such a manner that the information programmed and stored therein can be accessed only when such access does not interfere with the operation of the primary circuit. Important product processing and test information is stored in the programmable cells such as wafer number, lot number, processing parameters, special visual and test results and manufacturing rework data. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. Ser. No. 749,000 filed Aug. 23, 1991, now abandoned entitled "Synthetic Unrandomization of Oligomer Fragments" and assigned to the assignee of the present application. The entire disclosure of this application is incorporated by reference herein.
FIELD OF THE INVENTION
This invention relates to the development of drugs and of biologically active diagnostics and research reagents. In particular, this invention relates to the synthetic unrandomization of oligomer fragments to determine fragments specifically active for target molecules.
BACKGROUND OF THE INVENTION
Oligomers may be designed which are useful for therapeutic, diagnostic and research applications. In the past, development of biologically active oligomer substances was often limited to the modification of known sequences, unit by unit, until a desired Characteristic or efficacy was achieved. However, in addition to time drawbacks, protocols employing these types of methodologies are limiting in that the final product is based upon, and often not far removed from, the structure of the starting material.
Recently, new methods have been developed whereby drugs and biologically active substances can be "designed." A variety of combinatorial strategies have been described to identify active peptides. Houghton, et al. Nature 1991, 354, 84; Lam, et al., Nature 1991, 354, 82; Owens, et al., Biochem. Biophys. Res. Commun. 1991, 181, 402; Fodor, et al., Science 1991, 251, 767; Geysen, et al., Molecular Immunology 1986, 23, 709; Zuckermann, et al., Proc. Natl. Acad. Sci. 1992, 89, 4505; Rutter, et al., U.S. Pat. No. 5,010,175 issued Apr. 23, 1991.
Focusing on the field of nucleic acid-protein binding, combinatorial nucleic acid selection methods generally select for a specific nucleic acid sequence from a pool of random nucleic acid sequences based on the ability of selected sequences to bind to a target protein. The selected sequences are then commonly amplified and the selection process repeated until a few strong binding sequences are identified. These methods generally employ enzymatic steps within the protocol. Commonly T7 RNA polymerase and Taq I associated with polymerase chain reaction amplification methods are employed. One group recently identified a target sequence to the RNA-binding protein gp43. Tuerk and Gold, Science 1990 249, 505. Tuerk and Gold's "systematic evolution of ligands by exponential enrichment" (SELEX) method identified specifically bindable RNA sequences using four cycles of amplification of RNA sequences having variable portions therein and which were specifically bindable to gp43.
Another group designed DNA molecules which recognized the protease thrombin. Bock, et al., Nature 1992, 355, 564. This method involves the preparation of a population involving a random region flanked by known primer regions followed by PCR amplification and selection. Small molecule mimics of metabolic cofactors have been selectively recognized by RNA sequences in this manner by Ellington and Szostak, Nature 1990, 346, 818. These techniques were suggested to be useful to design oligonucleotide ligands, however their dependence upon enzymatic means for amplification and sequence determination limits their uses. Simpler methods for the identification of useful oligomers which are specifically bindable to target molecules and which express specific activity for target molecules are greatly desired. Methods which are not dependent upon enzymatic means would simplify protocols as well as expand the range of substrates with which the protocols would be effective. For example, presently there are over one hundred nucleotide analogs available. Cook, P. D., Anti-Cancer Drug Design 1991, 6, 585 and Uhlmann, et al., Chem. Rev. 1990, 90, 544. Since not all analogs are amenable to enzymatic processes, a non-enzymatic means for determining useful oligomer sequences which are specifically bindable to target sequences is greatly desired. Such methods could determine oligomers which are specifically bindable, not only to natural RNA-binding proteins, but also to any protein, nucleic acid, or other target molecule.
Methods are also greatly desired for determining useful oligomer sequences having particular desired activity, not limited to binding of target molecules. Such activity may include, but is not limited to, enzymatic or catalytic activity.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of the nucleotide sequence and Secondary structure of the ras 47-base-pair stem/loop RNA (SEQ ID NO:1).
FIG. 2A-2C representations of a gel image of a gel shift assay showing binding affinity of RNA oligonucleotides with ras 47-base-pair stem/loop RNA.
FIG. 3 is a schematic representation of inhibition of cytomegalovirus activity by four different oligonucleotide sets. Compound set C had the greatest activity against cytomegalovirus
FIG. 4 is a schematic representation of inhibition of influenza virus activity caused by four different oligonucleotide sets at concentration of 10 μM and 100 μM of oligonucleotide. Compound sets B and D had the greatest antiviral activities.
FIG. 5A is a schematic representation of the nucleotide sequence and secondary structure of the HIV TAR element (SEQ ID NO:20).
FIG. 5B is a representation of a gel image showing binding affinity of four oligonucleotide sets for the HIV TAR element at four different oligonucleotide concentrations. The oligonucleotide set NNNA.sup.• NGNNNN (SEQ ID NO:2) had the greatest binding affinity.
FIG. 6 is a schematic representation of the nucleotide sequence and secondary structure of the HIV gag-pol stem loop (SEQ ID NO:21).
FIG. 7 is a representing of a gel image showing the binding affinity of 100 pmoles of a phosphorothioate oligonucleotide set having the sequence NNNNTNNNN for the protein CD4 in the presence and absence of a competitor, dIdC. 100 pmoles exhibited binding which was visible at 0.5 and 1 μG CD4.
FIG. 8 is a representation of a gel image showing selection of an oligonucleotide with the highest affinity for a biotinylated target oligonucleotide. The "winner" sequence (top arrow) was evident through three rounds of the procedure. Lane 1 is the input material diluted 1:10. Lane 2 is the supernatant diluted 1:10. Lane 3 is the bound material. Lanes 4 and 5 are the supernatant (1:10 dilution) and bound material of round 2, respectively. Lanes 6 and 7 are the supernatant (1:10 dilution) and bound material or round 3, respectively. The top arrow indicates "winner" material. Randomer library material migrates to the position indicated by the bottom arrow.
SUMMARY OF THE INVENTION
Combinatorial strategies offer the potential to generate and screen extremely large numbers of compounds and to identify individual molecules with a desired binding specificity or pharmacological activity. This invention is directed to substantially non-enzymatic methods of determining oligomers which are specifically active for target molecules. Such oligomers preferably exhibit desired activity such as enzymatic or catalytic activity as well as binding affinity.
Methods of the present invention are useful for the determination of oligomers which have specific activity for target molecule from a pool of primarily randomly assembled subunits. Said methods involve repeated syntheses of increasingly simplified sets of oligomers coupled with selection procedures for determining the oligomer set having the greatest activity in an assay for desired activity.
Simplification of the pool occurs because, with each additional step of the methods, at least one additional position in the oligomer is determined. As a result, the possible number of different oligomer molecules in the pool decreases sequentially with the number of random positions remaining in the oligomer.
Freedom from the use of enzymes allows the application of these methods to any molecules which can be oligomerized in a controlled fashion.
In one embodiment of the present invention, methods for making oligonucleotides having specific activity for a target molecule are provided. These methods involve preparing a group comprising a plurality of sets of oligonucleotides, each oligonucleotide comprising at least four base units, by defining a common position in the oligonucleotides of the sets and synthesizing said sets of oligonucleotides such that each set has a different base unit in said common position and the base units which are not in the common position are randomized. Each of the sets are then assayed for activity against the target molecule and the set having the greatest activity for the target molecule is selected.
In other embodiments of the present invention each group of oligonucleotides may be subfractionated to provide subfractions of the sets of oligonucleotides. Each subfraction may be assayed against the target molecule and the set from which the subfraction having the highest activity was derived is selected.
These methods further comprise preparing a further group comprising a plurality of sets of oligonucleotides, each of the sets having in the previously defined common position the base unit appearing in the previously defined common position in the previously selected set. Each of said further group of sets has a different base unit in an additional, defined common position. The base units in positions of the oligonucleotides which are not in a common position are randomized. In other embodiments of the invention this group may subfractionated to provide subfractions of the sets of oligonucleotides.
Each of said sets or subfractions of sets may be assayed for activity for the target molecule and the set having the highest activity, or the set from which the subfraction having the highest activity was derived, is selected. The preceding steps may be performed iteratively.
Methods of determining an oligonucleotide cassette having specific activity for a target molecule are also provided by the present invention. These methods involve preparing a group comprising a plurality of sets of oligonucleotides, each oligonucleotide comprising at least four base units, by defining a common position in the oligonucleotides of the sets and synthesizing said sets of oligonucleotides such that each set has a different base unit in said common position and the base units which are not in the common position are randomized. Each of the sets are then assayed for activity for a target molecule and the set having the greatest activity for the target molecule is selected. Thereafter, a further group is prepared comprising a plurality of sets of oligonucleotides, each of the sets having in the previously defined common position the base unit appearing in the previously defined common position in the previously selected set. Each of said further group of sets has a different base unit in an additional defined common position, The base units in positions of the oligonucleotides which are not in a defined common position are randomized. Each set of said further group is assayed for specific activity for the target molecule and the set having the highest activity is selected. The preceding steps are performed iteratively to provide an oligonucleotide cassette having each position defined.
In other embodiments of the invention, methods for determining an oligonucleotide having specific activity for a target molecule are provided. Such methods comprise preparing a group comprising a plurality of sets of oligonucleotides, each of the oligonucleotides comprises at least one oligonucleotide cassette and at least one flanking region. A common position is defined in a flanking region of the oligonucleotides of the sets and the sets of oligonucleotides are synthesized such that each set has a different base unit in said common position and the base units which are not in the common position are randomized. Each of the sets are then assayed for activity for a target molecule and the set having the greatest activity for the target molecule is selected.
These methods also may comprise preparing a further group comprising a plurality of sets of oligonucleotides, each of the sets having in the previously defined common position the base unit appearing in the previously defined common position in the previously selected set. Each of said further group of sets having a different base unit in an additional, defined common position in the flanking region. The base units in positions of the oligonucleotides which are not in a common position in the flanking region are randomized. Each of the sets of oligonucleotides are assayed for specific activity for the target molecule and the set having the highest activity is selected. The preceding steps may be and preferably are performed iteratively.
In another embodiment of the present invention, methods for making polypeptides having specific activity for a target molecule are provided. These methods involve preparing a group comprising a plurality of sets of polypeptides, each polypeptide comprising at least four amino acids units by defining a common position in the polypeptides of the sets and synthesizing said sets of polypeptides such that each set has a different amino acid unit in said common position, the amino acid units which are not in said common position being randomized. Each of the sets is then assayed for activity and the set having the most activity is selected.
In yet another embodiment of the present invention each group of polypeptides is subfractionated to provide subfractions of the sets of polypeptides. Each subfraction may be assayed against the target molecule and the set from which the subfraction having the highest activity was derived is selected.
These methods further may comprise preparing a further group comprising a plurality of sets of polypeptides, each of the sets having in the previously defined common position the amino acid unit appearing in the previously defined common position in the previously selected set. Each of said further group of sets has a different amino acid unit in an additional, defined common position. The amino acid units in positions of the polypeptide which are not in a common position are randomized. In other embodiments of the invention this group may subfractionated to provide subfractions of the sets of polypeptides.
Each of said sets or subfractions of sets may be assayed for activity for the target molecule and the set having the highest activity, or the set from which the subfraction having the highest activity was derived, is selected. The preceding steps may be performed iteratively.
Methods of determining a polypeptide cassette having specific activity for a target molecule are also provided by the present invention. These methods involve preparing a group comprising a plurality of sets of polypeptides, each polypeptide comprising at least four amino acid units, by defining a common position in the polypeptides of the sets and synthesizing said sets of polypeptides such that each set has a different amino acid unit in said common position and the amino acid units which are not in the common position are randomized. Each of the sets are then assayed for activity for a target molecule and the set having the greatest activity for the target molecule is selected. Thereafter, a further group is prepared comprising a plurality of sets of polypeptides, each of the sets having in the previously defined common position the amino acid unit appearing in the previously defined common position in the previously selected set. Each of said further group of sets has a different amino acid unit in an additional defined common position. The amino acid units in positions of the polypeptides which are not in a defined common position are randomized. Each set of said further group is assayed for specific activity for the target molecule and the set having the highest activity is selected. The preceding steps are performed iteratively to provide a polypeptide cassette having each position defined.
In other embodiments of the invention methods for determining a polypeptide having specific activity for a target molecule are provided comprising preparing a group comprising a plurality of sets of polypeptides, each polypeptide comprising at least one polypeptide cassette and at least one flanking region by defining a common position in a flanking region of the polypeptides of the sets and synthesizing said sets of polypeptides such that each set has a different amino acid unit in said common position and the amino acid units which are not in the common position are randomized. Each of the sets are then assayed for activity for a target molecule and the set having the greatest activity for the target molecule is selected.
These methods further comprise preparing a further group comprising a plurality of sets of polypeptides, each of the sets having in the previously defined common position the amino acid unit appearing in the previously defined common position in the previously selected set. Each of said further group of sets has a different amino acid unit in an additional, defined common position in the flanking region. The amino acid units in positions of the polypeptides which are not in a common position in the flanking region are randomized. Each of the sets of polypeptides are assayed for specific activity for the target molecule and the set having the highest activity is selected. The preceding steps may be performed iteratively.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to non-enzymatic methods for determining oligomers which are active for a target molecule. In one embodiment of the present invention methods of determining oligonucleotides having specific binding affinity for a target molecule are provided. Another embodiment of the present invention provides methods determining oligonucleotides having enzymatic or catalytic activity for a target molecule. In still other embodiments of the present invention methods of determining polypeptides having specific binding affinity for a target molecule are provided. Methods of determining polypeptides having enzymatic or catalytic activity for a target molecule are also provided.
In the context of the present invention an oligomer is a string of units linked together by chemically similar covalent linkages. Nucleic acids linked together via phosphodiester bonds or amino acids linked together via peptide bonds are examples of naturally occurring oligomers.
In the context of this invention, the term "oligonucleotide" refers to a polynucleotide formed from naturally occuring bases and furanosyl groups joined by native phosphodiester bonds. This term effectively refers to naturally occurring species or synthetic species formed from naturally occurring subunits or their close homologs. The term "oligonucleotide" may also refer to moieties which have portions similar to naturally occurring oligonucleotides but which have non-naturally occurring portions. Thus, oligonucleotides may have altered sugar moieties or inter-sugar linkages. Exemplary among these are the phosphorothioate and other sulfur-containing species which are known for use in the art. In accordance with some preferred embodiments, at least some of the phosphodiester bonds of the oligonucleotide have been substituted with a structure which functions to enhance the stability of the oligonucleotide or the ability of the oligonucleotide to penetrate into the region of cells where the viral RNA is located. It is preferred that such substitutions comprise phosphorothioate bonds, phosphotriesters, methyl phosphonate bonds, short chain alkyl or cycloalkyl structures or short chain heteroatomic or heterocyclic structures. Most preferred are CH 2 --NH--O--CH 2 , CH 2 --N(CH 3 )--O--CH 2 , CH 2 --O--N(CH 3 )--CH 2 , CH 2 --N(CH 3 )--N(CH 3 )--CH 2 and O--N(CH 3 )--CH 2 --CH 2 structures where phosphodiester is O--P--O--CH 2 ). Also preferred are morpholino structures. Summerton, J. E. and Weller, D. D., U.S. Pat. No. 5,034,506 issued Jul. 23, 1991. In other preferred embodiments, such as the protein-nucleic acid (PNA) backbone, the phosphodiester backbone of the oligonucleotide may be replace with a polyamide backbone, the bases being bound directly or indirectly to the aza nitrogen atoms of the polyamide backbone. P. E. Nielsen, et al., Science 1991 254 1497. In accordance with other preferred embodiments, the phosphodiester bonds are substituted with other structures which are, at once, substantially non-ionic and non-chiral, or with structures which are chiral and enantiomerically specific. Persons of ordinary skill in the art will be able to select other linkages for use in practice of the invention.
Oligonucleotides may also include species which include at least some modified base forms. Thus, purines and pyrimidines other than those normally found in nature may be so employed. Similarly, modifications on the furanosyl portion of the nucleotide subunits may also be effected, as long as the essential tenets of this invention are adhered to. Examples of such modifications are 2'-O-alkyl- and 2'-halogen-substituted nucleotides. Some specific examples of modifications at the 2' position of sugar moieties which are useful in the present invention are OH, SH, SCH 3 , F, OCN, O(CH 2 ) n N 2 , O(C 2 ) n CH 3 where n is from 1 to about 10; C 1 to C 10 lower alkyl, substituted lower alkyl, alkaryl or aralkyl; Cl, Br, CN, C 3 , OCF 3 , O--, S--, or N-- alkyl; O--, S--, or N-alkenyl; SOCH 3 , SO 2 CH 3 ; ONO 2 ; N 3 ; N 3 ; NH 2 ; heterocycloalkyl; heterocycloalkaryl; aminoalkylamino; polyalkylamino; substituted silyl; an RNA cleaving group; a conjugate; a reporter group; an intercalator; a group for improving the pharmacokinetic properties of an oligonucleotide; or a group for improving the pharmacodynamic properties of an oligonucleotide and other substituents having similar properties. Sugar mimetics such as cyclobutyls may also be used in place of the pentofuranosyl group. Oligonucleotides may also comprise other modifications consistent with the spirit of this invention. Such oligonucleotides are best described as being functionally interchangeable with yet structurally distinct from natural oligonucleotides. All such oligonucleotides are comprehended by this invention so long as they effectively function as subunits in the oligonucleotide.
In the context of the present invention polypeptide refers to a plurality of joined amino acid units formed in a specific sequence from naturally occurring amino acids. Said amino acid units are generally linked together via peptide bonds. Naturally occurring subunits include the twenty commonly occurring amino acids, as well as other less common naturally occurring amino acids. Polypeptides, in the context of the present invention, also refers to moieties which are similar to polypeptides but which have non-naturally occurring portions. Hence, polypeptides may have altered linkages or may be comprised of altered amino acid residues such as D-amino acids or other modifications consistent with the spirit of the present invention. Such modified polypeptides have also been referred to in the art as polypeptide analogs.
The methods of the present invention are useful to determine oligomers which are specifically active for a target molecule. In the context of the present invention determine refers to concurrent identification of the sequence of an oligomer and the binding activity of the oligomer for a target molecule. Further, determine refers to the identification of oligomers having activity such as catalytic or enzymatic activity. In some instances, neither the oligomer sequence nor its specific activity is known prior to performance of methods of the present invention. In other cases, while a particular oligomer sequence may be known, those skilled in the art may not recognize its activity for a particular target molecule. In still other cases, activity of a known sequence for a particular target molecule may be optimized.
Oligomers of the present invention are assayed for specific activity for a target molecule. In some embodiments of the present invention, specific activity refers to binding affinity of said oligomers for a target molecule. In other embodiments of the present invention, specific activity encompasses binding affinity and further encompasses activity such as catalytic or enzymatic activity. As used herein, binding affinity refers to the ability of the oligomer to bind to a target molecule via hydrogen bonds, van der Waals interactions, hydrophobic interactions, or otherwise. For example, an oligonucleotide may have binding affinity for another oligonucleotide to which it is complementary, i.e., to which it has the ability to hybridize due to Watson-Crick base pair attraction.
Target molecules of the present invention may include any of a variety of biologically significant molecules. Target molecules may be nucleic acid strands such as significant regions of DNA or RNA. Target molecules may also be proteins, carbohydrates, or glycoproteins. In some preferred embodiments of the present invention, said target molecule is a protein such as an immunoglobulin, receptor, receptor binding, ligand, antigen or enzyme and more specifically may be a phospholipase, tumor necrosis factor, endotoxin, interleukin, plasminogen activator, protein kinase, cell adhesion molecule, lipoxygenase, hydrolase or transacylase. In other preferred embodiments of the present invention said target molecules may be important regions of the human immunodeficiency virus, Candida, herpes viruses, papillomaviruses, cytomegalovirus, rhinoviruses, hepatitises, or influenza viruses. In still further preferred embodiments of the present invention said target molecule is ras 47-mer stem loop RNA, the TAR element of human immunodeficiency virus or the gag-pol stem loop of human immunodeficiency virus (HIV) or the HIV tat protein. Still other targets may induce cellular activity. For example, a target may induce interferon.
In some aspects of the present invention, a target protein may be identified based upon the fact that proteins bind to free aldehyde groups while nucleic acids do not. Thus, a sampling of proteins which have been identified as potential targets may be bound to solid supports having free aldehyde groups such as nitrocellulose filters. For example, up to 96 proteins may be bound in individual wells of a 96-well nitrocellulose filter manifold. In some embodiments of the present invention sequential concentrations of protein may be tested to determine the effect of lowering the protein target concentration. Thereafter, an identical detectably labeled oligonucleotide group may be incubated with each protein sample under binding conditions. The preparation of labeled oligonucleotide groups is described herein. The support is washed and the presence or absence of binding is detected whereby binding indicates that the oligonucleotide group has specific activity for a given protein. As will be apparent to one skilled in the art, methods of detection of binding will be dependent upon the label used.
In the present invention, a group of sets of random oligomers is prepared. Oligomers may be prepared by procedures known to those skilled in the art. Specifically, oligonucleotides and polypeptides may be prepared by solid state synthesis or by other means known to those skilled in the art. For example, oligonucleotides may be prepared using standard phosphoramidite chemistry. In some embodiments of the present invention oligomer groups may further be labeled, such as by radiolabeling or fluorescent labeling. For example, an oligonucleotide group may be labeled at the 5' termini of the oligonucleotides using γ- 32 P! ATP and T4 polynucleotide kinase. Labeled oligomer groups may be useful in a number of assays which can not be performed using unlabeled oligomer groups.
Oligomers of each set may be of predetermined length. It is preferred that such oligomers be from about 4 to about 50 units in length. It is more preferred that such oligomers be from 4 to about 40 units in length. It is also preferred for some embodiments of the present invention that less than about 10 units of an oligomer are randomized. In some cases, it may be desirable to provide an oligomer which initially comprises 6, 7, or 8 random units.
In some embodiments of the present invention, the length of said oligomer need not be constant throughout the procedure. For example, an 8-mer may be assayed to determined the sequence having highest binding affinity for a target molecule. Subsequently, the 8-mer may be extended and tested as a 15-mer to determine the 15-mer sequence having the highest binding affinity for the target molecule.
Groups of the present invention are made up of a plurality of sets which may remain constant throughout the procedure. From about three to about twenty sets can make up each group. In one preferred embodiment of the present invention four sets make up each group. In another embodiment of the present invention twenty sets make up each group. Alternatively, three sets may make up each group.
The number of sets that make up each group is dependent upon the number of possible distinct chemically similar units which exist for any one species of molecule. For example, an oligonucleotide group may be comprised of four sets since there are four similar units making up the nucleic acid species, i.e. guanine, adenine, cytosine, thymine or adenine, guanine, cytosine and uracil. Alternatively, an oligonucleotide group may be comprised of more than four sets representing for example, the four commonly occurring bases and additional modified bases. Twenty sets may make up a polypeptide group, representing the twenty commonly occurring amino acids, lysine, arginine, histidine, aspartic acid, glutamic acid, glycine, asparagine, glutamine, cysteine, serine, threonine, tyrosine, alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine and tryptophan. Greater than twenty sets may also make up a polypeptide group if uncommon or modified amino acids are included in the assay. Subgroups of basic units may also determine the number of sets in any one group. For example, in procedures to determine a particular polypeptide, sets may represent acidic, basic and neutral amino acid units, i.e. three sets. The number of sets in groups in any one procedure need not remain constant throughout, but may fluctuate. For example, in a one group there may be three sets representing three types of polypeptides and in a next group there may be twenty sets representing each commonly occurring amino acid.
The use of additional units such as nucleotide or amino acid analogs may be preferred in some instances where it is desirable to increase the complexity of the group of oligomers. The complexity of a group may be calculated by the formula P×P N where P is the number of different units used and N is the number of positions in an oligomer which are randomized. The complexity of a set (Q) is represented by the formula P N . Table 1 illustrates the change in group complexity as a result of the increase in the number of analogs used. Of course, the number of different units used also determines the number of sets prepared.
TABLE 1______________________________________Group Structure = NNN × NNN Complexity ofNumber of different each set (Q) Total Group Complexityanalogs used (P) (P.sup.6) (P · P.sup.6)______________________________________4 4.sup.6 = 4096 4 × 4096 = 16,3845 5.sup.6 = 15,625 5 × 15,625 = 78,1256 6.sup.6 = 46,656 6 × 46,656 = 279,9367 7.sup.6 = 117,649 7 × 117,649 = 823,5438 8.sup.6 = 262,144 8 × 262,144 = 2,097,1529 9.sup.6 = 531,441 9 × 531,441 = 4,782,96910 10.sup.6 = 1,000,000 10 × 1,000,000 = 10,000,000______________________________________
Each of the sets in a group has a different unit in a common position of said oligomer. For example, in determining an oligonucleotide, only one of four sets will contain an adenine in a common position, only one set will contain a guanine in a common position, etc. The remaining positions in each set of oligonucleotides are comprised of any combination of random basic units.
In further embodiments of the present invention, common positions are comprised of multiple oligomer positions. For example, for a 9-mer, one common position may be the third position of the 9-mer, or the common position may be comprised of the third position and the fourth position of the 9-mer.
In some aspects of the invention, it may be desirable to begin a procedure by unrandomizing central regions of an oligomer as opposed to end regions, such as the 3' or 5' regions of an oligonucleotide or the carboxy or amino terminal regions of a polypeptide, since it has been found that in some cases defining a central position had a greater affect on specific activity of an oligomer than did defining an end region during a similar stage of a determination. For example, in Example 8 an attempt to fix a 3' position did not yield results that distinguished the sets, whereas a position in the center of the oligomer was fixed to yield results which were detectable.
Furthermore, there is a complexity limit to the detectability of activity (signal-to-noise), especially in oligomers having a high percentage of unrandomized positions. It is likely that with largely unstructured, conformationally dynamic oligomers, a plethora of relatively weak specific activity towards many target molecules will result. As discussed, this may be improved by increasing the number of units used. An additional method of increasing specific activity of a group of oligomers is to constrain the oligomer sterically. For example, an oligonucleotide may be sterically constrained by providing complementary ends at the 3' and 5' termini of the region of interest, which region comprises randomized positions. The complementary ends will hybridize to form a secondary structure.
The detectable specific activity may also be enhanced by the determination and/or use of an oligomer "cassette". An oligomer cassette is a oligomer for which a sequence has been determined. The cassette may be comprised of a sequence of known significance, or may be determined such as by the procedures of the present invention. As used herein an oligonucleotide cassette is a defined oligonucleotide sequence and a polypeptide cassette is a defined polypeptide sequence. In some embodiments of the present invention an oligomer may comprise at least one oligomer cassette and at least one flanking region of unrandomized positions. In other embodiments of the present invention an oligomer may be comprised of more than one cassette wherein each cassette is flanked by at least one region of randomized positions. For example, a oligonucleotide cassette of known sequence may be flanked at the 3' terminus, the 5' terminus, or both the 3' and 5' termini.
In some embodiments of the present invention it may also be desirable to subfractionate a group of oligomers to provide subfractions of the sets of oligomers, thus delimiting the degree of complexity that is assayed at one time. This both diminishes the amount of total material that must be used in a determination in order to have sufficient representation of all individual sequences and it also enhances the signal to noise ratio of the assay by starting with oligomer sets enriched in the most active sequences. Any physical-chemical or functional characteristic, combined with an appropriate separation modality may be used to empirically subfractionate a group, thereby resulting in (or deriving) numerous distinct subfractions of diverse character, and diminished complexity. It is theorized that if a particular fit sequence or sequences exist within the original group for a particular target, it will be found enriched in a limited number of the reduced complexity subfractions.
One skilled in the art would be apprised of the broad selection of appropriate selection modalities which are available. The strategy followed will of course depend upon the properties of the elements of the oligomer group. It will further be appreciated by one skilled in the art that as the number of group elements increases and the structural and chemical diversity enlarges, there will be a greater selection of separation strategies leading to increased subfractionation capacity. By way of example, it is envisioned that novel oligomers may be resolved into subfractions by any one or a combination of size, positive or negative charge, hydrophobicity and affinity interactions. Many chromatographic and analytical instrumental methods are known to those skilled in the art which may be effectively applied to the separation strategies encompassed herein.
In some embodiments of the invention each set of oligomers is assayed for desired activity. In other embodiments of the present invention, identical empirical assays of subfractions of oligomer sets described above are performed in order to identify those subfractions having the strongest activity as indicated by a strong signal to noise ratio. The set having the highest activity or the set from which the subfraction having the highest activity is derived is selected and further unrandomization may be performed if desired.
Specific activity may be detected by methods known to those skilled in the art. Appropriate assays will be apparent to one skilled in the art and oligomer concentration, target molecule concentration, salt concentration, temperature, buffer and buffer concentration may be altered to optimize a particular system. In some preferred embodiments of the present invention, binding conditions simulate physiological conditions. In other preferred embodiments of the present invention binding occurs in a buffer of from about 80 mM to about 110 mM sodium chloride and from about 10 to about 15 mM magnesium chloride. Oligomers may also generally be assayed for catalytic or enzymatic activity.
Gel shift assays may be used to visualize binding of an oligomer to a target molecule. In accordance with methods of the present invention, radiolabelled target molecule bound to oligomer of the present invention may be run on a gel such as a polyacrylamide gel. Bound target molecule has less mobility than unbound target molecule, and therefore will not migrate as far on the gel. The radioactive label allows visualization of the "shift" in mobility by standard procedures for example, by means of X-ray radiography or by using a phosphorimager (Molecular Dynamics). In other embodiments of the present invention a gel shift assay may be performed wherein an unlabeled target molecule may be bound to radiolabelled oligomer.
Radiolabeled oligomer may also be useful for the streptavidin capture of a biotinylated-target bound to an oligomer. For example, a target may be biotinylated prior to incubation with radioactively labeled random oligomer sets. Each set is thereafter incubated with the target under identical conditions and the target molecule is captured on streptavidin-coated beads. Consequently any oligomer which bound to the target will also be captured. Streptavidin-coated beads are available commercially such as for example, streptavidin-coated manganese particles available from Promega. The beads are washed and the reaction may be reequilibrated to further enrich the "winning" sequence. The percent of oligomers from each set which bound is determined by the amount of radioactivity remaining after wash. Measuring radioactivity in a sample may be performed by a number of methods known in the art. For example, the amount of radioactivity may be determined directly by counting each sample, using for example a scintilation counter. Samples may also be run on a polyacrylamide gel, the gel may be placed under x-ray film and a densitometric reading of the autoradiogram may be taken.
Assays are not limited to detecting binding affinity but may also detect other desired activities such as catalytic or enzymatic activity. Some embodiments of the present invention provide for detection of specific activity by a cell culture assay. For example, inhibition of cell adhesion may indicate binding of oligomer to a target molecule involved in cell adhesion. In further embodiments of the present invention further groups of sets are prepared. Each of said further groups have a selected number of sets of oligomers. Sets of further groups have in a previously defined common position, units appearing in the previously defined common position in previously selected set. Each set of the further sets has a different unit in an additional defined common position. The units in the positions of the oligomer that are not in a common position are randomized.
For example, in one group, the previously selected set may be comprised of an adenine in the previously defined common position. A further group may retain said adenine in said previously defined common position, and at another defined common position each set in said further group may be comprised of a different unit, either adenine, guanine, thymine or cytosine. The units in the positions of the oligomer that are not in a common position are randomized.
In further embodiments of the present invention, common positions are comprised of multiple oligomer positions as described above. For example, for a 9-mer, the one common position may be the third position of the 9-mer, or the common position may be comprised of the third position and the fourth position of the 9-mer.
Procedures useful for increasing the complexity of an oligomer group, and/or increasing specific activity of an oligomer described previously are equally applicable to said further groups. Thus, oligomer groups may be comprised of multiple units, may be sterically constrained and may be subfractionated prior to assaying for specific activity. Furthermore, oligomers of further groups may comprise one or more cassettes.
Sets are again assayed for desired activity. The steps described above may be performed iteratively.
The following examples are illustrative, but not limiting of the invention.
EXAMPLE 1
Synthesis of DNA Oligonucleotides
Unmodified DNA oligonucleotides are synthesized on an automated DNA synthesizer (Applied Biosystems model 380B) using standard phosphoramidite chemistry with oxidation by iodine. β-cyanoethyldiisopropyl phosphoramidites may be purchased from Applied Biosystems (Foster City, Calif.).
EXAMPLE 2
Synthesis of RNA Oligonucleotides
Unmodified RNA oligonucleotides having random base sequences were synthesized on an automated DNA synthesizer (Applied Biosystems model 380B) using modified standard phosphoramidite chemistry synthesis with oxidation by iodine. The standard synthesis was modified by increasing the wait step after the pulse delivery of tetrazole- to 900 seconds. β-cyanoethyldiisopropyl phosphoramidites were purchased from Applied Biosystems (Foster City, Calif.). The bases were deprotected by incubation in methanolic ammonia overnight. Following base deprotection, the oligonucleotides were dried in vacuo. The t-butyldimethylsilyl protecting the 2' hydroxyl was removed by incubating the oligonucleotide in 1M tetrabutylammoniumfluoride in tetrahydrofuran overnight. The RNA oligonucleotides were further purified on C 18 Sep-Pak cartridges (Waters, Division of Millipore Corp., Milford, Mass.) and ethanol precipitated.
EXAMPLE 3
Synthesis of Phosphorothioate Oligonucleotides
Phosphorothioate oligonucleotides represent a class of oligonucleotide analog that is substantially nuclease resistant. Phosphorothioate RNA oligonucleotides and phosphorothioate DNA oligonucleotides were synthesized according to the procedure set forth in Examples I and 2 respectively, replacing the standard oxidation bottle by a 0.2M solution of 3H-1,2-benzodithiole-3-one 1,1-dioxide in acetonitrile for stepwise thiation of phosphite linkages. The thiation cycle wait step was increased to 68 seconds and is followed by the capping step.
EXAMPLE 4
Synthesis of 2'-O-alkyl Phosphorothioate Oligonucleotides
2'-O-methyl phosphorothioate oligonucleotides were synthesized according to the procedures set forth in Example 3 substituting 2'-O-methyl β-cyanoethyldiisopropyl phosphoramidites (Chemgenes, Needham, Mass.) for standard phosphoramidites and increasing the wait cycle after the pulse delivery of tetrazole and base to 360 seconds. Similarly, 2'-O-propyl, 2'-O-phenyl and 2'-O-nonyl phosphorothioate oligonucleotides may be prepared by slight modifications of this procedure.
EXAMPLE 5
Preparation of Pyrene Oligonucleotide Analogs
Oligonucleotides were prepared by incorporating 2' aminopentoxyadenosine at desired sites. The oligonucleotides were dissolved in 0.2M NaHCO 3 buffer and treated with 50 fold excess of N-hydroxysuccinimide ester of pyrene-1-butyric acid dissolved in dimethylformamide. The resultant mixture is incubated at 37° C. for 4-5 hours and the conjugate is purified by reverse phase HPLC followed by desalting in a G-25 Sephadex column.
EXAMPLE 6
Synthesis of Oligonucleotide Having Randomized Positions
Four columns of the DNA synthesizer were packed with a mixture containing an equal amount of adenosine(A)-, cytidine(C)-, guanosine(G)- and uracil(U)-controlled pore glass (CPG, Chemgenes, Needham, Mass.). At coupling steps where a given nucleotide base was desired, the defined phosphoramidite was delivered to each column. At each "random" coupling step, an equimolar mixture of all four phosphoramidites was delivered to each column.
EXAMPLE 7
Preparation of Radiolabeled Groups
Oligonucleotide groups prepared in accordance with Example 1 through 6 may be radiolabeled using γ- 32 P! ATP and T4 polynucleotide kinase as described in Maniatis, et al. "Molecular Cloning: A Laboratory Manual" (Cold Spring Harbor, N.Y.).
EXAMPLE 8
Effect of Site of Unrandomization on Activity
Twenty-four sets of phosphorothioate oligonucleotides were prepared in accordance with Examples 3 and 6 as set forth in Table 2.
TABLE 2______________________________________Set 1 ANNNNN Set 13 NNNANNSet 2 CNNNNN Set 14 NNNCNNSet 3 GNNNNN Set 15 NNNGNNSet 4 TNNNNN Set 16 NNNTNNSet 5 NANNNN Set 17 NNNNANSet 6 NCNNNN Set 18 NNNNCNSet 7 NGNNNN Set 19 NNNNGNSet 8 NTNNNN Set 20 NNNNTNSet 9 NNANNN Set 21 NNNNNASet 10 NNCNNN Set 22 NNNNNCSet 11 NNGNNN Set 23 NNNNNGSet 12 NNTNNN Set 24 NNNNNT______________________________________
Each of the sets is tested for activity against a target molecule to determine which order of unrandomization gives the highest initial specific activity.
EXAMPLE 9
Preparation of a Biotin Oligonucleotide Group
An oligonucleotide group having the sequence TNNNXNNNTB, wherein N is any of A, G, C, or U, X is one of A, G, C and U and B is biotin, is prepared in accordance with Examples 3 and 6. The sequence is designed with flanking thymidines to provide sites for radiolabeling. A control having the sequence TNNNXNNNT is also prepared in accordance with Examples 3 and 6.
EXAMPLE 10
Preparation of Oligonucleotide Group comprising Nucleotide Analogs.
Oligonucleotide groups having the sequence NNNXNNNU are prepared in accordance with Example 1 and 6 incorporating one or more of the nucleoside analogs 2'-O-nonyl adenosine, N6-imidazoylpropyl guanosine, 2'-O-aminopentyl cytidine, 2'-O-pentyl-adenosine, 2'-O-pentyl-guanosine, 2'-O-pentyl-cytidine, 3'-terminal 2'-O-methyl uridine and 6-amino-2-hydroxylmethyl-1-hexanol. The nucleosides, 2'-O-nonyl adenosine, N6-imidazoylpropyl guanosine, 2'-O-aminopentyl cytidine, 2'-O-pentyl-adenosine, 2'-O-pentyl-guanosine, 2'-O-pentyl-cytidine, 3'-terminal 2'-O-methyl uridine were prepared by modification of the methods described in PCT US91/00243 filed Jan. 11, 1991. 6-amino-2-hydroxylmethyl-l-hexanol is available commercially. The nucleosides are modified to provide the corresponding phosphoramidite by methods known to those skilled in the art.
EXAMPLE 11
Gel-shift Assay of Random 2-0-Methyl Oligonucleotlde Binding to ras RNA Target
The ras 47-mer stem/loop RNA was enzymatically synthesized, 32 P end-labeled according to standard procedures, and gel-purified. 2'-O-Methyl oligonucleotide analog libraries comprising four sets were prepared in accordance with Examples 4 and 6. Each set was tested for binding against the RNA target and a "set K D " was determined in accordance with the following procedure.
In a first round the ras RNA target was incubated at a concentration of approximately 10 pM with each of the four random 2'-O-methyl oligonucleotide sets, at concentrations of 5, 10, 50 and 100 μM in a buffer consisting of 100 mM NaCl and 10 mM MgCl 2 . The hybridization was carried out for four hours at 37° C., followed by electrophoretic separation of bound vs. unbound material on a 20% acrylamide gel in Tris-Borate buffer (TBE) plus 50 mM NaCl, run at 25 W for four hours. The gel was dried and the radioactive bands were visualized on a phosphorimager (Molecular Dynamics). The ras stem/loop target alone is the lowest band visible on the gel (highest mobility). As this target binds oligonucleotide (non-radioactive), the mobility of the ras target is decreased, shifting the band to a higher position on the gel (complex). In FIG. 2A no binding is seen for the oligonucleotide sets NNNNGNNNN or NNNNUNNNN, but NNNNANNNN shows a slight shift at 100 uM and NNNNCNNNN shifts more than 50% of the target to the bound form at 50 uM oligonucleotide concentration.
The protocol was then repeated in Round 2. The ras RNA target was incubated at a concentration of approximately 10 pM with each of the four random oligonucleotide sets synthesized according to the method described above, at concentrations of 1 and 10 μM to provide the gel image of FIG. 2B which shows that oligonucleotide sets NNNNCNANN, NNNNCNGNN and NNNNCNUNN show minimal binding. NNNNCNCNN shows a shift of more that 25% of the target at 1 μM and about 50% of the target at 10 μM. In Round 3 the ras RNA target was incubated with the random oligonucleotide sets at concentrations of 0.1 and 1 μM to provide the gel image of FIG. 2C where only NNCNCNCNN showed binding, exhibited by a shift of greater than 50% of the target.
Table 3 sets forth results of nine rounds performed to determine the "winner" sequence which binds to the ras RNA target. K D are in μM.
TABLE 3______________________________________ K.sub.DRound Sequence* Q** A C G U______________________________________1 NNNNXNNNN 65,536 22 10 >100 >1002 NNNNCNXNN 16,384 >10 4 >10 >103 NNXNCNCNN 4,096 >10 0.5 >10 >104 NNCXCNCNN 1,024 >10 0.15 >10 >105 NNCCCXCNN 256 0.08 >1 0.4 >16 NNCCCACXN 64 0.05 >0.5 0.08 >0.57 NXCCCACAN 16 > 0.1 >0.1 0.03 >0.18 NGCCCACAX 4 0.05 0.02 0.05 0.0429 XGCCCACAC 1 0.03 0.05 0.02 0.01______________________________________ *wherein N is any of A, C, G or T; **Q is set complexity.
As illustrated in Table 3, it was not difficult to distinguish the set with the lowest K D (μM) at each round of synthesis and screening.
As expected for oligonucleotide hybridization reactions, positions near the center of the oligonucleotide had a greater effect on the K D than positions on the extreme 5' or 3' ends. For example, an attempt to fix the 3' position in round 4 did not yield results that distinguished the sets. An alternative position was selected for round 4 which yielded a clear winner, and then the sequence was elucidated from the center of the oligomer to the ends. The final oligonucleotide selected by the procedure is complementary to the single stranded loop region of the target RNA.
EXAMPLE 12
ELISA for Detection of Inhibition of Herpes Simplex Virus-1
ELISA for detection of HSV-1 envelope glycoprotein B (gB) was performed by infection of normal dermal fibroblast cells (NHDF, Clonetics) with HSV-1 (KOS) at a multiplicity of infection of 0.05 PFU/cell. Following virus adsorption, cells were washed and treated with growth media containing oligoeucleotide. Oligonucleotides were tested in triplicate wells at four concentrations. Cells were fixed 48 hours postinfection and assayed for the presence of HSV-1 gB antigen by ELISA. Standard deviation were typically within 10%.
EXAMPLE 13
Inhibition of Herpes Simplex Virus-1 Activity by Phosphorothioate Oligonucleotide Sets
A group of 65,536 unique 8-mers in 4 sets of 16,348 was prepared in accordance with Examples 3 and 6 each was screened for activity against human herpes simplex virus type 1 (HSV-1) in cell culture in accordance with the procedure described in Example 12. As illustrated in Table 4, antiviral activity was observed with increasing potency at each round of synthesis and screening, with no difficulty discerning the most active set (in bold) in each round.
TABLE 4______________________________________ IC.sub.50 (μM) when × =Round Sequence* Q** A C G T______________________________________1 NNNXNNNN 16,348 >100 >100 70 >1002 NNNGNNNX 4,096 >100 >100 30 >1003 NNNGNXNG 1,024 >100 >100 15 >1004 NXNGNGNG 256 30 30 5 205 XGNGNGNG 64 20 20 1.5 206 GGNGXGNG 16 10 10 1.5 107 GGXGGGNG 4 1.3 1.3 0.5 1.38 GGGGGGXG 1 0.7 0.7 1.1 0.4______________________________________ *where N is any of A, C, G or T; **where Q is set complexity.
The oligonucleotide set containing a fixed guanine had the most activity in every round of HSV screening except the last round, resulting in selection of a guanine at nearly all fixed positions.
EXAMPLE 14
Optimization of G4 Core Containing 8-met oligonucleotide for HSV-1 Antiviral Activity
To determine the optimal 8:met containing a G 4 core, a oligonucleotide group was designed as shown in Table 5, using the oligonucleotide cassette GGGG.
TABLE 5______________________________________Sequence* Most Active × = IC.sub.50 (μM)______________________________________NNGGGGNX A 2.5NNGGGGXA T 1.1XNGGGGTA G 0.8GXGGGGTA C 0.8______________________________________ *N is any of A, G, T or C.
As shown in Table 5, optimization of the sequences surrounding the G 4 core produced a 3 fold increase in antiviral activity in four rounds of synthesis and screening, suggesting that although the G 4 core is the most important component of the activity, potency can be modulated by the flanking sequences.
EXAMPLE 15
Assay for Detection of Inhibition of Human Immunodeficiency Virus
The human T-lymphoblastoid CEM cell line was maintained in an exponential growth phase in RPMI 1640 with 10% fetal calf serum, glutamine, and antibiotics. On the day of the assay, the cells were washed and counted by trypan blue exclusion. These cells (CEM-IIIB) were seeded in each well of a 96-well microtiter plate at 5×10 3 cells per well. Following the addition of cells to each well, the compounds were added at the indicated concentrations and serial half log dilutions. Infectious HIV-1 IIIB was immediately added to each well at a multiplicity of infection determined to give complete cell killing at 6 days post-infection. Following 6 days of incubation at 37° C., an aliquot of supernatant was removed from each well prior to the addition of the tetrazolium dye XTT to each well. The XTT was metabolized to a formazan blue product by viable cells which was quantitatively measure spectrophotometrically with a Molecular Devices Vmax Plate Reader. The XTT assay measures protection from the HIV-induced cell killing as a result of the addition of test compounds. The supernatant aliquot was utilized to confirm the activities determined in the XTT assay. Reverse transcriptase assays and p24 ELISA were performed to measure the amount of HIV released from the infected cells. Protection from killing results in an increased optical density in the XTT assay and reduced levels of viral reverse transcriptase and p24 core protein.
EXAMPLE 16
Inhibition of Human Immunodeficiency Virus by Phosphorothioate Oligonucleotide Sets
A group of 65,536 unique 8-mers in 4 sets of 16,348 each were prepared in accordance with Examples 3 and 6 and screened for activity in accordance with Example 12. The compound sets are described in Table 6. Table 6 sets forth the IC 50 (μM) for four oligonucleotide sets.
TABLE 6______________________________________Set Sequence* IC.sub.50 (μM)______________________________________A NNNN A NNN inactiveB NNNN C NNN inactiveC NNNN G NNN 5D NNNN T NNN inactive______________________________________ *where N is any of A, C, G, or T.
Set C sowed 50% inhibition of HIV-induced cytopathic effects at 5 μM, while the other compound sets were inactive at concentration up to 25 μM.
EXAMPLE 17
Assay for the Detection of Inhibition of Cytomegalovirus
Confluent monolayer cultures of human dermal fibroblasts were treated with oligonucleotide sets at the indicated concentrations in serum-free fibroblast growth media. After overnight incubation at 37° C., culture medium containing oligonucleotide was removed, cells were rinsed and human cytomegalovirus was added at a multiplicity of infection of 0.1 pfu/cell. After a 2 hour adsorption at 37° C., virus was removed and fresh fibroblast growth medium containing oligonucleotide sets at the indicated concentrations was added. Two days after infection, old culture medium was removed and replaced with fresh fibroblast growth medium containing oligonucleotide sets at the indicated concentrations. Six days after infection media was removed, and cells fixed by addition of 95% ethanol. HCMV antigen expression was quantitated using an enzyme linked immunoassay. Primary reactive antibody in the assay was a monoclonal antibody specific for a late HCMV viral protein. Detection was achieved using biotinylated goat anti-mouse IgG as secondary antibody followed by reaction with streptavidin conjugated B-galactosidase. Color was developed by addition of chlorophenol red B-D-galactopyranoside and absorbance at 575 nanometers measured using an ELISA plate reader. Results are expressed as percent of untreated control and were calculated as follows: ##EQU1##
EXAMPLE 18
Inhibition of Cytomegalovirus by Phosphorothioate Oligonucleotide Sets
A group of 65,536 unique phosphorothioate 8-mers in 4 sets of 16,438 were prepared in accordance with Examples 3 and 6 and screened for activity against the human cytomegalovirus in accordance with Example 14. The compound sets A (NNNNANNN), B (NNNNGNNN), C (NNNNCNNN) and D (NNNNTNNN), where N is any of A, G, C or T, were screened at a range of concentration from 10 to 200 μM. The results shown in FIG. 3 show that compound set B had the greatest activity against cytomegalovirus, causing approximately 20% inhibition at a 100 μM dose and 90% inhibition at a 200 μM dose. Sets A, B and D exhibited minimal to no antiviral activity.
EXAMPLE 19
Assay to Detect Inhibition of Influenza A Virus
Vero cells were pretreated overnight with randomer sets by direct addition to the-media at 10 μM and 100 μM concentrations. After overnight treatment cells were infected with influenza A/PR/8 at a MOI of 0.05. Following infection cells were incubated for 48 hours in the presence of oligonucleotide. After incubation cells were fixed with methanol and air dried. Monolayers were then assayed by ELISA for matrix protein. Primary antibody was a monoclonal antibody specific for matrix protein of influenza A virus (B020 Bioproducts for Science). Second antibody was goat antimouse IgG conjugated to alkaline phosphatase (BRL, Bethesda, Md.). Substrate was ATTO-PHOS reagent, JBL. Fluorescence was measured using a Millipore Cytofluour 2300 with excitation at 450 nM and emission read at 580 nM.
EXAMPLE 20
Inhibition of Influenza Virus by Phosphorothioate Oligonucleotide Sets
A group of 65,536 unique phosphorothioate 8-mers in 4 sets of 16,438 was prepared in accordance with Examples 3 and 6 and was screened for activity against the Influenza A virus as described in Example 16. The compound sets A (NNNNANNN), B (NNNNGNNN), C (NNNNCNNN) and D (NNNNTNNN), where N is any of A, G, C or T, were screened at 10 μM and 100 μM. The results as shown in FIG. 4 show that sets C and D had the greatest antiviral activities, set C exhibited approximately 50% inhibition and set D exhibited approximately 35% inhibition of viral activity. A and B exhibited minimal activity.
Data are the arithmetic mean and standard error of triplicate data points of a single experiment.
EXAMPLE 21
Determination of Oligonucleotides which Induce Interferon
A phosphorothioate oligonucleotide group comprising 20 sets having the sequence N N N N X N N N where N is any of adenine, guanine, cytosine or thymidine and X is one of adenins, guanine, cytosine or thymidine is prepared in accordance with Examples 3 and 6. The sets are set forth in Table 7.
TABLE 7______________________________________ Set Modification______________________________________ 1-4 natural 5-8 2'-O-methyl 9-12 2'-O-propyl 13-16 2'-O-pentyl 17-20 2'-O-nonyl______________________________________
An ELISA is performed to determine the set which is most effective to induce interferon. The nucleotide in the most effective set is fixed and sets having the fifth position fixed and the fourth position one of adenine, guanine, cytosine or thymidine is prepared. An ELISA is performed to determine the set which is most effective to induce interferon. The steps are repeated until all of the positions are determined.
EXAMPLE 22
Gel Shift Assay of Random Pyrene Oligonucleotide Sets Binding to HIV TAR Element
The HIV TAR element is a structured RNA found on the 5'-end of all HIV transcripts. A gel shift has been used to analyze the binding of four oligonucleotide sets to the HIV TAR element (illustrated in FIG. 5A). The target RNA has a three base bulge that is required for binding of the transcriptional activation protein tat. The oligonucleotides set forth in Table 8 were prepared in accordance with Examples 5 and 6, each containing a pyrene analog (indicated by A*).
TABLE 8______________________________________ SEQ-ID NO:______________________________________SET 1 N N N A* N A N N N N 3SET 2 N N N A* N C N N N N 4SET 3 N N N A* N G N N N N 2SET 4 N N N A* N U N N N N 5______________________________________
The assay uses a 15 pM concentration of the radioactively labeled target and an 0.1, 1, 10, and 100 μM concentrations of each set. Binding of molecules from the set to the target results in a slower mobility complex. Set 3 binds best to TAR as illustrated in FIG. 5B wherein 100 μM of the oligonucleotide set caused a shift of approximately 50% of the target. 100 μm of the oligonucleotide set 2 caused a shift of approximately 25% of the target. Sets 1 and 4 caused minimal shift of the target. The sixth position will be fixed as a G and another position unrandomized in the second round of synthesis and assays.
EXAMPLE 23
Random Oligonucleotide Set Binding to HIV gag-pol Triple Strand
Binding to double stranded DNA or RNA is possible by formation of a three stranded complex with the incoming third strand binding in the major groove of the duplex RNA or DNA. The molecular nature of the interaction between the oligomer and target need not be known in order to practice the technique. Thus, it is possible that novel interactions between oligomers and DNA or RNA will be responsible for binding. FIG. 6 illustrates a double stranded RNA structure from HIV known as the gag-pol stem loop (Vickers and Ecker, Nucleic Acids Research). One of the limitations in the design of triple strand interactions is the need to have a long stretch of homopurines as a target. The 3' (right) side of the gag-pol stem loop is homopurine except for a pair of cytosines near the bottom of the stem. To determine the best oligonucleotide to bind to the gag-pol stem loop, a group of RNA oligonucleotide sets was designed to bind to the purine-rich strand of the gag-pol stem-loop by Hoogstein base pairing and prepared in accordance with Examples 2 and 6. At the position of the two cytosines the sequence was randomized to provide the sequences set forth in Table 9. Binding to the gag-pol stemloop was measured by gel shift analysis as previously described in Example 8 with the following modifications: the radiolabeled gag-pol RNA was incubated with the oligonucleotide in 100 mM NaCl, 25 mM TRIS acetate pH5, 2 mM Mg Cl 2 , 1 mM spermidine. The gel was a 15% acrylamide with 50 mM NaCl 2 mM MgCl 2 added to the running buffer.
The results in Table 9 show that in round 1 the oligonucleotide set CCCUUCCCNUC (SEQ ID NO: 8) had the greatest affinity for the target with a K D of 50. In the second round the C was fixed in the eighth position and the ninth position was determined. The oligonucleotide CCCUUCCCCUC (SEQ ID NO: 12) had the greatest affinity for the target in the ninth round with a K D of 1. Thus, a triple strand-binding sequence can be optimized.
TABLE 9______________________________________Set Sequence K.sub.D (μM) SEQ ID NO:______________________________________Round 1A.sub.1 CCCUUCCANUC >100 6B.sub.1 CCCUUCCGNUC >100 7C.sub.1 CCCUUCCCNUC 50 8D.sub.1 CCCUUCCUNUC 100 9Round 2A.sub.2 CCCUUCCCAUC 10 10B.sub.2 CCCUUCCCGUC 1.0 11C.sub.2 CCCUUCCCCUC 1 12D.sub.2 CCCUUCCCUUC 10 13______________________________________
EXAMPLE 24
Random Oligonucleotide Binding to Transcription Factors
A radiolabeled oligonucleotide group was prepared having the sequence NNGGGGNX wherein N is any of A, G, T or C and X is one or A, G, T or C as described in Examples 3, 6 and 7. The group was screened for binding to the HIV tat protein, which is a transcription factor produced by the virus as described in Example 24. Binding activity was observed.
EXAMPLE 25
Random 2'-O-Methyl Oligonucleotide Binding to Endothelin-1
Receptor and radiolabeled ligand were supplied in a kit obtained from DuPont/NEN. Assays were performed according to the manufacturer's instructions. A random 2'-O-methyl group was prepared in accordance with Examples 4 and 6 to provide four sets having the sequences GCGNNNANNNNNNCGC (SEQ ID NO: 14); GCGNNNGNNNNNNCGC (SEQ ID NO:15); GCGNNNCNNNNNNCGC (SEQ ID NO:16); GCGNNNUNNNNNNCGC (SEQ ID NO: 17) where N is any of A, G, C or U. Each set was diluted to 100 μM in an assay buffer provided in the kit, then incubated with the receptor and ligand as per the manufacturer's protocol. Following the incubation, ligand- bound receptor was separated from unbound by vacuum filtration through glass filters. The bound ligand was then eluted from the filter in scintilation fluid and counted in a scintilation counter. Receptor and ligand were incubated with an excess of unlabeled ligand in order to establish the level of non-specific binding (NSB) to the filters and with no oligonucleotide set (zero) to establish the level of complete binding.
The results shown in Table 10 indicate that set B was most active against Endothelin-1.
TABLE 10______________________________________ CPM NET CPM % I______________________________________NSB 284 -- --zero 1421 1140 100A 1223 939 82B 1200 916 80C 1347 1063 93D 1330 1046 92______________________________________
EXAMPLE 26
Random 2'-O-Methyl Oligonucleotide Binding to Leukotriene B4
Receptor and radiolabeled ligand were supplied in a kit obtained from DuPont/NEN. Assays were performed according to the manufacturer's instructions. A random 2'-O-methyl group was prepared in accordance with Examples 4 and 6 to provide four sets having the sequences GCGNNNANNNNNNCGC (SEQ ID NO: 14); GCGNNNGNNNNNNCGC (SEQ ID NO:15); GCGNNNCNNNNNNCGC (SEQ ID NO:16); GCGNNNUNNNNNNCGC (SEQ ID NO: 17) where N is any of A, G, C or U. Each set was diluted to 100 μM in an assay buffer provided in the kit, then incubated with the receptor and ligand as per the manufacturer's protocol. Following the incubation, ligand- bound receptor was separated from unbound by vacuum filtration through glass filters. The bound ligand was then eluted from the filter in scintilation fluid and counted in a scintilation counter. Receptor and ligand were incubated with an excess of unlabeled ligand in order to establish the level of non-specific binding (NSB) to the filters and with no oligonucleotide set (zero) to establish the level of complete binding. The results shown in Table 11 indicate that set D was most active against leukotriene B4.
TABLE 11______________________________________ CPM NET CPM % I______________________________________NSB 383 -- --zero 1063 680 100A 989 606 89B 953 570 84C 900 517 76D 894 511 75______________________________________
EXAMPLE 27
Phosphorothioate and 2'-O-Methyl Oligonucleotide Binding to the Vital Receptors CD4
Two groups of oligonucleotides were prepared. A phosphorothioate oligonucleotide group was prepared in accordance with Examples 3 and 6. A 2'-O-methyl oligonucleotide group was prepared in accordance with Examples 4 and 6. Both groups have the sequence NNNNTNNNN where N is any of A, C, G or T.
100 pmoles of each group of random oligonucleotides is 5' end labeled to high specific activity with γ- 32 P! ATP and T4 polynucleotide kinase. Each labeled group is reacted with the protein CD4 at room temperature in a buffer consisting of 100 mM KCl, 1.5 mM mgCl 2 , 0.2 mM EDTA, 10% glycerol, 1 mM DTT, and 20 mM HEPES (pH=7.9). poly dI•dC is added as indicated as a non-specific competitor. After 1 hour protein bound oligonucleotide is separated from unbound by electrophoresis on a 6% native acrylamide gel in 1X TBE buffer. The results of the phosphorothioate oligonucleotide assay is shown in FIG. 7 and indicates binding of the oligonucleotide to the protein (at the arrow). No binding has was detected by the 2'-O-methyl set. Binding has been observed with the phosphorothioate pool against the tat protein.
EXAMPLE 28
Preparation of Random Group of Polypeptides and Assay for Binding Thereof
Polypeptides may be used in the practice of this invention. Monomer amino acids are easily oligomerized into peptides using the appropriate precursor chemicals and instruments available to those skilled in the art, such as those that can be purchased from Applied Biosystems.
The first round of synthesis is as follows:
TABLE 12______________________________________Position 1 2 3 4 5 6 7 8 9______________________________________Set 1 X X X X B X X X XSet 2 X X X X A X X X XSet 3 X X X X W X X X XSet 4 X X X X L X X X X______________________________________
where A is defined as an acidic amino acid, B is defined as a basic amino acid, W is defined as a neutral amino acid, L is defined as a lipophilic amino acid, and X is defined as any amino acid from the above identified group.
Each of the above sets is tested for inhibition of cell adhesion using a cell culture assay in which the ICAM-1 mediated binding of cells is measured as described. Dustin, M. L. and Springer, T. A. J. Cell Biol. 1988, 107, 321. The set showing greatest inhibition of cell adhesion at the lowest polypeptide concentration is selected.
The protocol is repeated, retaining the selected amino acid at position 5, and sequentially testing each remaining position to reach an optimal binding sequence.
EXAMPLE 29
Identification of Oligonucleotide Sequence Using Streptavidin Capture of Biotinylated Target
0.2 μM of a target oligonucleotide having the sequence 3'dBAB AGA CGT CTT GCG 5' (SEQ ID NO: 18) wherein B is biotin, was incubated for 30 minutes at room temperature with 10 μM of a radiolabeled 2'-O-methyl oligonucleotide group prepared in accordance with Examples 4, 6 and 7 having the sequence NNN NCN CNN wherein N is any of adenine, cytosine, thymidine or guanine, and 0.1 μM of a radioactively labeled oligonucleotide complementary to the target (dTCTGCAGAACGC; SEQ ID NO: 19). The target oligonucleotide and any bound radioactiveIy labeled oligonucleotide was captured on streptavidin-coated magnasphere beads (Promega), the beads were washed, and supernatant removed. The captured radioactively labeled oligonucleotide was removed from the beads and run on a polyacrylamide gel. FIG. 8 sets forth a sample gel which indicates that a "winner" can be separated from an excess of random sequence oligonucleotides. The procedure was repeated. In lane i was run a 1:10 dilution of the original solution prior to capture. Lane 2 is the supernatant diluted 1:10. Lane 3 is the bound material from the first round. A band of "winner" sequence is apparent, migrating to the first arrow. Lanes 4 and 5 are the supernatant (1:10 dilution) and bound material from the second round, respectively. The second round results in a "winner" band of greater purity. Lanes 6 and 7 are the supernatant (1:10 dilution) and bound material from the third round, respectively. The supernatant does not contain any radiolabeled oligonucleotides. The third round results in a "winner" band with little to no non-specific oligonucleotide.
EXAMPLE 30
Identification of a Protein Target
A group of oligonucleotides having the sequence NNNNNNNN wherein N is any one of adenine, guanine, thymidine or cytosine is prepared in accordance with Examples 3 and 6. The group is labeled using γ- 32 P! ATP and T4 polynucleotide kinase.
In individual wells of a 96-well nitrocellulose filter manifold, the following proteins are incubated in a solution of phosphate buffer saline: plasminogen activator A 2 , tumor necrosis factor α, tumor necrosis factor β and gp120. Phosphate buffer saline only is added to a control well. The filter is washed. An aliquot of the labeled group of oligonucleotides is added to each well and incubated at room temperature for 10 minutes. The filter is washed and the counts in each well over background are counted to determine whether binding of the oligonucleotide to the protein occurred.
EXAMPLE 31
Determination of Phosphorothioate Oligonuclectide Having Binding Affinity for Nitrocellulose Bound Proteins
An oligonucleotide analog group comprising four sets of oligonucleotides eight positions in length is prepared in accordance with Examples 3 and 6 and each set is tested for binding against the nitrocellulose-bound proteins identified in accordance with Example 27. The set having the highest affinity for each protein, as indicated by counts per well is the "winner set" for each protein. Results of the first round are as set forth in Table 13.
TABLE 13______________________________________Position 1 2 3 4 5 6 7 8 Protein winner______________________________________Set 1 N N N N A N N N plasminogen activator A.sub.2, tumor necrosis factor αSet 2 N N N N G N N N no winnerSet 3 N N N N C N N N gp120Set 4 N N N N T N N N tumor necrosis factor______________________________________ β
The filter is washed and wells counted. In a second round, the A is fixed in the fifth position and the sets (NNNAANNN), (NNNGANNN), (NNNCANNN), and (NNNTANNN) are prepared for testing in the wells containing plasminogen activator A 2 and tumor necrosis factor α. Similarly, sets in which the C is fixed in the 5th position or a T is fixed in the 5th position are prepared for testing in the gp120 and tumor necrosis factor β wells, respectively. By the eight round, "winner" sequences for all four target proteins are determined.
EXAMPLE 32
Determination of an Oligonucleotide Having Binding Affinity for a Target Protein using Subfractionated Sets of Oligonucleotides
An oligonucleotide analog group comprising four sets of oligonucleotides eight positions in length is prepared in accordance with Examples 3 and 6 wherein each of the sets has a different one of adenins, guanine, thymidine and cytosine in the 5th position, and the rest of the positions are randomized to provide the group: NNNNANNN, NNNNGNNN, NNNNTNNN, and NNNNCNNN. Each set is subfractionated by charge with an anion exchange column. Each subfraction is tested for affinity for the target protein by gel shift assay. The subfraction from the set having an adenine in the 5th position has the highest binding affinity. In a further round, the 5th position is fixed to contain an adenins in the 5th position, and each set has a different nucleotide in the fourth position to provide the group NNNAANNN, NNNTANNN, NNNGANNN, and NNNCANNN. The sets are again subfractionated by charge with an anion exchange column and the subfractions are tested for affinity for the target protein by gel shift assay. The steps are repeated until each position is determined.
__________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 21(2) INFORMATION FOR SEQ ID NO:1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 47 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:GGUGGUGGUGGGCGCCGUCGGUGUGGGCAAGAGUGCGCUGACCAUCC47(2) INFORMATION FOR SEQ ID NO:2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 10 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(ix) FEATURE:(A) NAME/KEY: misc_feature(B) LOCATION: 4(D) OTHER INFORMATION: /note="pyrene analog of adenine"(xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:NNNANGNNNN10(2) INFORMATION FOR SEQ ID NO:3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 10 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(ix) FEATURE:(A) NAME/KEY: misc_feature(B) LOCATION: 4(D) OTHER INFORMATION: /note="pyrene analog of adenine"(xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:NNNANANNNN10(2) INFORMATION FOR SEQ ID NO:4:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 10 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(ix) FEATURE:(A) NAME/KEY: misc_feature(B) LOCATION: 4(D) OTHER INFORMATION: /note="pyrene analog of adenine"(xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:NNNANCNNNN10(2) INFORMATION FOR SEQ ID NO:5:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 10 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(ix) FEATURE:(A) NAME/KEY: misc_feature(B) LOCATION: 4(D) OTHER INFORMATION: /note="pyrene analog of adenine"(xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:NNNANUNNNN10(2) INFORMATION FOR SEQ ID NO:6:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 11 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:6:CCCUUCCANUC11(2) INFORMATION FOR SEQ ID NO:7:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 11 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:7:CCCUUCCGNUC11(2) INFORMATION FOR SEQ ID NO:8:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 11 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:8:CCCUUCCCNUC11(2) INFORMATION FOR SEQ ID NO:9:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 11 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:9:CCCUUCCUNUC11(2) INFORMATION FOR SEQ ID NO:10:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 11 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:10:CCCUUCCCAUC11(2) INFORMATION FOR SEQ ID NO:11:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 11 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:11:CCCUUCCCGUC11(2) INFORMATION FOR SEQ ID NO:12:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 11 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:12:CCCUUCCCCUC11(2) INFORMATION FOR SEQ ID NO:13:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 11 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:13:CCCUUCCCUUC11(2) INFORMATION FOR SEQ ID NO:14:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 15 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:14:GCGNNNANNNNNCGC15(2) INFORMATION FOR SEQ ID NO:15:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 15 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:15:GCGNNNGNNNNNCGC15(2) INFORMATION FOR SEQ ID NO:16:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 15 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:16:GCGNNNCNNNNNCGC15(2) INFORMATION FOR SEQ ID NO:17:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 15 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:17:GCGNNNUNNNNNCGC15(2) INFORMATION FOR SEQ ID NO:18:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 13 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:18:AAGACGTCTTGCG13(2) INFORMATION FOR SEQ ID NO:19:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 12 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: DNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:19:TCTGCAGAACGC12(2) INFORMATION FOR SEQ ID NO:20:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 29 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:20:GCCAGAUCUGAGCCUGGGAGCUCUCUGGC29(2) INFORMATION FOR SEQ ID NO:21:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 26 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: RNA (genomic)(xi) SEQUENCE DESCRIPTION: SEQ ID NO:21:CUGGCCUUCCUACAAGGGAAGGCCAG26__________________________________________________________________________ | Methods useful for the determination of oligomers which have specific activity for a target molecule from a pool of primarily randomly assembled subunits are provided. The disclosed methods involve repeated syntheses of increasingly simplified sets of oligomers coupled with selection procedures for determining oligomers having the highest activity. Freedom from the use of enzymes allows the application of these methods to any molecules which can be oligomerized in a controlled fashion. | 2 |
RELATED APPLICATIONS
This application is a continuation of utility patent application Ser. No. 11/216,929 entitled Plastic Expandable Utility Shed filed Aug. 30, 2005, now U.S. Pat. No. 7,581,357 the contents of which are herein incorporated by reference in their entirety. This application is also related to Ser. No. 29/230,885 filed May 27, 2008, now U.S. Design Pat. No. D529,623, and Ser. No. 29/230,978 filed May 27, 2005, now U.S. Design Pat. No. D525,715, the contents of which are herein incorporated by reference in their entirety.
FIELD OF THE INVENTION
This invention relates generally to plastic utility sheds, and more specifically to a modular roof system constructed of injection molded plastic panels for creating plastic utility shed roofs of various sizes from standardized components.
BACKGROUND OF THE INVENTION
Utility sheds are necessary for lawn and garden care, as well as general all-around home storage space. Typically, items such as garden tractors, snow blowers, tillers, ATVs, motorcycles, lawn tools and the like are stored within utility sheds for the convenience of the homeowner.
The prior art has proposed a number of different panel systems, or kits, comprising blow molded and/or extruded panels which are combined with connector members for forming storage structures, e.g. utility sheds. Unfortunately, blow molding and/or extrusion of panels for utility sheds has resulted in shortcomings within the state of the art products. For example, due to the nature of the manufacturing process, blow molded and/or extruded plastic components cannot be formed with the intricate shapes and/or sharp corners required for integrated connectors. Therefore, these systems require extruded metal or plastic connector members having a specific cross-sectional geometry that facilitates an engagement between the blow molded or extruded panels to complete the structure.
A particularly common structure for the connector members is one having an I-beam cross section. The I-beam defines free edge portions of the connector member which fit within appropriately dimensioned and located slots in the panel members. U.S. Pat. No. D-371,208 teaches a corner extrusion for a building sidewall that is representative of the state of the art I-beam connector members. The I-beam sides of the connector engage with the peripheral edge channels of a respective panel and thereby serve to join such panels together at right angles. Straight or in-line versions of the connector members are also included in the kits to join panels in a coplanar relationship to create walls of varying length.
Another drawback associated with blow molded panels is the requirement of an inner and an outer wall. The inner and outer walls are a necessary product of the blow molding manufacturing process. While the inner wall may add some rigidity to the panels, it also adds a significant amount of weight and dramatically increases the volume of plastic necessary to form a panel of a given size when compared to other methods of manufacturing, such as injection molding.
A further drawback associated with blow molded panels relates to accurate control of wall thickness throughout the panels. The blow molding process does not allow the wall thickness of the panels to be accurately controlled. Once the molten plastic is conveyed to the tooling, there is minimal control over where the plastic flows during formation of the panel. Also, the blow molding process does not allow the intentional formation of thick and thin sections within a single panel for engineered rigidity at the points of high stress or high load concentration.
Extruded panels generally require hollow longitudinal conduits for strength. Due to the nature of the manufacturing process, the conduits are difficult to extrude in long sections for structural panels. Thus, they also require connectors to achieve adequate length for utility shed roofs. A common structure for connecting extruded members has a center I-beam with upper and lower protrusions for engaging the conduits. Wall panels utilizing these connectors are vulnerable to buckling under loads and may have an aesthetically unpleasing appearance. Moreover, roof loads from snow and the like may cause such walls to bow outwardly due to the clearances required between the connectors and the internal bores of the conduits. U.S. Pat. No. 6,250,022 discloses an extendable shed utilizing side wall connector members representing the state of the art. The connectors have a center strip with hollow protrusions extending from its upper and lower surfaces along its length; the protrusions being situated to slidably engage the conduits located in the side panel sections to create the height needed for utility shed walls.
The aforementioned systems can also incorporate roof and floor panels to form a freestanding enclosed structure such as a small utility shed. U.S. Pat. Nos. 3,866,381; 5,036,634; and 4,557,091 disclose various systems having inter-fitting panel and connector components. Such prior art systems, while working well, have not met all of the needs of consumers to provide the structural integrity required to construct larger sized structures.
Larger structures must perform differently than small structures. Large structures must withstand increased wind and snow loads when compared to smaller structures. Paramount to achieving these needs is a panel system which eliminates the need for extruded connectors to create enclosure walls which resist panel separation, buckling, and racking. A further problem is that the wall formed by the panels must tie into the roof and floor in such a way as to unify the entire enclosure. Also, from a structural standpoint, the enclosure should include components capable of withstanding the increased wind, snow, and storage loads required by large structures.
Therefore, what is needed in the art is an injection molded modular roof system for utility enclosures. The modular roof system should achieve objectives such as light weight single wall construction. The construction of the panels should eliminate the need for extruded I-beam connectors to create a roof assembly which resists panel separation, buckling, and racking. The roof assembly should be capable of withstanding the wind and snow loads typically associated with utility enclosure roofs.
There are also commercial considerations that must be satisfied by any viable utility shed enclosure system or kit; considerations which are not entirely satisfied by state of the art products. The roof assembly must be formed of relatively few component parts that are inexpensive to manufacture by conventional techniques. The roof assembly must also be capable of being packaged and shipped in a knocked-down state. In addition, the roof assembly must be modular and facilitate the creation of a family of roof assemblies that vary in size but which share common, interchangeable components.
Finally there are ergonomic needs that a roof assembly must satisfy to achieve acceptance by the end user. The roof assembly must be easily and quickly assembled using minimal hardware and requiring a minimal number of tools. In addition, the roof assembly must not require excessive strength to assemble or include heavy component parts. Moreover, the roof assembly must assemble together in such a way so as to not detract from the internal storage volume of the resulting enclosure or otherwise negatively affect the utility of the structure.
SUMMARY OF THE INVENTION
The present invention provides a system including injection molded roof panels, headers, and ridge caps having integrated connectors which combine to form a family of variously sized roofs for utility enclosures. The roof panels, headers, and ridge caps are formed of injection molded plastic to create light-weight components having integrally formed ribs and gussets for strength and integrity. The injection molding also facilitates integrally formed connectors so that the panels, headers and ridge caps interlock with one another without the need for separate connectors. In addition, the ridge caps and/or roof panels may be formed of translucent plastic for natural lighting.
Accordingly, it is a primary objective of the instant invention to provide a plastic utility roof assembly.
It is a further objective of the instant invention to provide a plastic roof assembly which utilizes roof panels and ridge caps having single wall construction with integrally formed ribs and gussets for a lightweight yet robust roof assembly.
It is yet another objective of the instant invention to provide a plastic roof assembly which accommodates injection molding plastic formation of the components for increased structural integrity.
It is a still further objective of the invention to provide a modular header system which allows standard components to be utilized for different width roofs.
Still another objective of the instant invention is to provide a roof system in which the components include integrally formed connectors.
Yet another objective of the instant invention is to provide a roof system which includes components having predetermined sizes for creating roofs of varying dimensions using common components.
Still yet another objective of the instant invention is to provide a roof assembly which reduces the number of components required to assemble a roof and simplifies construction.
Other objects and advantages of this invention will become apparent from the following description taken in conjunction with any accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. Any drawings contained herein constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a front perspective view of an enclosure comprising an assembled wall system, roof headers, and a ridge cap.
FIG. 2 is a front perspective view of an enclosure comprising an assembled wall system, headers and the left half of the roof assembly.
FIG. 3 is an exploded view of a complete roof assembly.
FIG. 4 is a front perspective view of a two piece header.
FIG. 5 is a rear perspective view of a two piece header.
FIG. 6 is a front perspective exploded view of a two piece header with a strap support.
FIG. 7 is a front perspective view of a three piece header.
FIG. 8 is a rear perspective view of a three piece header.
FIG. 9 is a front perspective exploded view of a three piece header with a strap support.
FIG. 10 is a bottom view of a three piece header.
FIG. 11 is a perspective view of the back side of a header and the underside of the roof panels.
FIG. 12 is a perspective view of the front side of a header and the underside of roof panels.
FIG. 12A is an enlarged view of the connection between the header and a roof panel.
FIG. 13 is a perspective view of the top of the roof panels and a section of the ridge cap.
FIG. 14 is a perspective view of the underside of the roof panels and a section of the ridge cap.
FIG. 15 is an enlarged view taken along line 2 - 2 of FIG. 14 illustrating the connection between the ridge cap and a roof panel.
FIG. 16 is a perspective view of the connection between a roof panel and a wall panel.
FIG. 16A is an enlarged view taken along line 3 - 3 of FIG. 16 illustrating the connector which joins a roof panel to a wall panel.
FIG. 17 is a perspective view of an assembled roof and wall panel.
FIG. 17A is an enlarged view taken along line 4 - 4 of FIG. 17 illustrating the assembled connection between a roof panel and a wall panel.
FIG. 18 is a perspective view of an assembled roof and wall panel including a roof support.
FIG. 18A is a enlarged view of the connector between a roof panel and the roof support.
FIG. 19 is a perspective view of two different roof panels utilized for enclosures of different widths.
FIG. 20 is an enlarged view of the connection between two roof panels.
FIG. 21 is an enlarged view of one roof panel of the connection shown in FIG. 20 .
FIG. 22 is a section view taken along line 1 - 1 of FIG. 13 illustrating the overlapping connection between the roof panels.
DETAILED DESCRIPTION OF THE INVENTION
While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiments illustrated.
FIGS. 1-3 show perspective views of a heavy duty plastic utility enclosure, generally referenced as 10 , constructed according to a preferred embodiment of the present invention. The roof assembly generally includes header assemblies 410 , roof panels 460 , roof supports 520 , and a ridge cap assembly 530 which are shown in an exploded view in FIG. 3 . The header assembly is a truss like structure molded with an aesthetically pleasing generally smooth wall 412 on its outer surface (FIGS. 3 , 6 , 7 , and 9 ) and integrally formed box bracing 414 ( FIGS. 4-9 ) and a plurality of pockets 416 constructed and arranged to accept roof support members 470 on its inner surface. In the preferred embodiment the header assembly is constructed of a center member 418 and a pair of outer members 420 ( FIG. 3 ). This type of construction permits the center member to be added or removed to construct different size enclosures while the outer members remain the same. Each member of the header assembly includes an upper surface 422 and a lower surface 424 . The lower surface 424 includes a plurality of inwardly extending engagement sockets 426 constructed and arranged to cooperate with removable and replaceable bosses 428 and/or door hinge pins 430 . The bosses 428 or hinge pins 430 are slid into their respective engagement sockets 426 until the integrally formed spring tabs 432 ( FIGS. 6 and 9 ) engage corresponding apertures formed in the engagement sockets. The end surfaces 434 , 436 of the header members includes means to connect them together illustrated herein as a plurality of outwardly extending, inter-fitting tubes 438 . The tubes are constructed and arranged to extend into a socket 439 formed in an adjacently positioned header member until integrally formed spring locks 440 ( FIG. 8 ) engage a corresponding aperture. This construction provides a load distributing connection between the header members that prevents separation and bowing of the assembly under load. In addition, the design provides a sealed connection between the panels preventing weather and insect infiltration. The resultant header created by the combination of the interlocking members benefits from high structural integrity and reliable operation.
Referring to FIGS. 4-6 , a two piece header embodiment is illustrated. With this embodiment additional means are provided for attaching the header members together illustrated herein as a C-shaped clip 444 . The C-shaped clip is inserted into apertures 446 provided in each of the header members ( FIG. 5 ). The C-shaped clip is provided to prevent separation and provide load support integrity to the header assembly. For additional support ad rigidity the header assembly is constructed and arranged to cooperate with a metal support member 448 . The metal support member is attached to the header members with fasteners 450 and anchors 452 . The anchors are inserted through the apertures 454 on the rear side of the header members ( FIG. 5 ). In this manner FIGS. 8 and 9 show how the strap is employed with a three piece header assembly.
The headers are attached to the wall assemblies by sliding the bosses 428 into sockets (not shown) positioned in the top portion of the wall panels until the integrally formed spring clips 442 ( FIG. 3 ) engage apertures formed in the sockets. The result is a positive lock that maintains alignment of the wall panels in the same plane and prevents bowing or bending of one panel relative to another one.
Referring to FIGS. 1-3 and 5 , at least three roof supports 520 are inserted into their respective pockets 416 in each of the headers and may optionally be secured in place with suitable fasteners. The roof supports are preferably constructed of a metal such as steel, but may be constructed of other materials well known in the art capable of providing structural support to the roof assembly. Such materials may include but are not limited to wood and/or plastic as well a suitable combinations thereof. FIG. 1 illustrates the placement of the support beams in the headers of the preferred embodiment.
Referring to FIGS. 3 and 13 roof panels 460 are formed as either a central roof panel 462 or an end roof panel 464 . Each central roof panel has a top surface 466 , a bottom surface 468 , a first locking edge 470 , a second locking edge 472 , a third locking edge 474 and a closed edge 476 . Along the bottom surface 468 adjacent to the closed edge 476 is another connection means illustrated herein as a plurality of sockets 478 constructed and arranged to receive roof connectors 480 ( FIGS. 16 and 17 ). The roof connectors are constructed and arranged to cooperate with pockets (not shown) located in the top portion of the wall panels as well as the sockets 478 located on the lower surface of the roof panels. A series of spaced apart structural ribs 482 extend across the bottom surface of each roof panel to provide rigidity and increased weight carrying capacity to the roof assembly. The first 470 and second 472 locking edges of the roof panel include another connection means illustrated herein as a W-shaped overlapping connection 484 ( FIG. 22 ). The distal portion 486 of the first locking edge 470 of the overlapping connection includes a plurality of ramp-locks 488 constructed and arranged to cooperate with apertures 490 formed into the second locking edge overlapping connection. The W-shaped overlapping connection provides a water resistant seal between the panels and prevents the panels from bowing or separating under wind or snow loads. The second locking edge 472 further includes a downwardly extending wave shaped rib 492 ( FIG. 21 ). This rib is constructed and arranged to fit into a corresponding trough 494 formed on the first locking edge 470 ( FIG. 20 ). The connection of the wave shaped rib 492 and corresponding trough 494 provides an additional water resistant seal between the panels. Any water that may enter the trough flows downwardly along the trough and out through drain 496 ( FIG. 20 ). Drain 496 is located outside of the walls so that water is prevented from entering the enclosure.
Sockets 478 located on the lower surface of the roof panels comprise two sockets members ( FIG. 20 ). Each socket member is located along a locking edge of a roof panel (FIGS. 16 , 17 , and 20 ). Roof connectors 480 are formed with two upwardly extending members 500 and a lower member 502 which spans members 500 . The upwardly extending members are provided with ramp-locks 504 and the lower member is provided with two ramp-locks 506 . The connectors 480 are constructed and arranged to allow the upwardly extending members to slide into sockets 478 and the lower member to slide into a socket on the top portion of a wall panel ( FIGS. 16 and 17 ). The ramp-locks engage apertures 508 in socket 478 and ramp-locks 506 engage apertures 510 in the wall panel socket. Another type of roof connector 512 also slides into sockets 478 which are located on the lower side of the roof panel and spaced between the ends of the roof panels as shown in FIG. 18 . The lower portion of connector 512 is provided with a groove which engages roof supports 520 to provide support for the roof panel along its length. Connectors 512 are provided with ramp locks 514 which engage apertures 508 in sockets 478 to provide a locking connection. The connectors 512 and roof supports 520 provide roof support for additional snow loads.
The end roof panels 464 are similar to the central roof panels in that they have a top surface, a bottom surface, sockets 478 on the bottom surface located along either a first or second locking edge, a third locking edge and a closed end. They differ from the central roof panels in that they are not as wide and have a channel 516 located along either a first or second locking edge. In place of a locking edge adjacent the channel there is a smooth edge surface 518 ( FIGS. 3 and 12 ). This edge extends beyond the header and presents an aesthetically pleasing surface. The width of channel 516 is the same as the depth of the header assemblies 410 so as to form a connection between the roof and the header assemblies and create a weather resistant seal between the two members. Channels 516 are also include apertures 522 which engage ramp-locks 524 located along the upper edge of the header assemblies ( FIG. 12 ) to secure the end roof panels to the header assemblies.
The central and end roof panels are available in at least two different lengths as shown in FIG. 19 . The pattern of the structural ribs 482 on the bottom surface of the roof panels is selected so that the shorter roof panel can be formed without retooling. As can be seen in FIG. 14 if the formation of the roof panel is stopped at the transverse rib 482 a shorter roof panel, with the proper structural elements, will be the result.
The roof assembly also includes a ridge cap assembly 530 which is formed from a plurality of like constructed ridge cap members 531 ( FIG. 13 ). Each ridge cap member includes an integrally formed tubular connector 533 at one end thereof and an integrally formed aperture 532 at the opposite end thereof. The tubular connector 533 of one ridge cap member engages the aperture 532 of an adjacent ridge cap member thereby interlocking the members together. There are also two ridge cap members which cooperate with the end roof panels and header assemblies ( FIG. 3 ) and include apertures 536 which cooperate with ramp-locks 524 formed on the header assemblies ( FIG. 12 ) to secure the ridge cap members to the header assemblies. Each of these ridge cap members is formed with an end portion which corresponds to the edge surface 518 of the end roof panels so as to present an aesthetically pleasing edge surface when located adjacent thereto. The ridge cap members may be made from a translucent material to enhance natural lighting of said enclosure.
The third locking edge of each roof panel includes an interlocking tubular connection 526 which is constructed and arranged to cooperate with a conjugately shaped receiver 528 formed in the ridge cap members 531 ( FIG. 3 ) to join roof panels on opposite sides of the roof and to create a weather resistant seal. The tubular connection 526 includes integrally formed ramp-locks 534 which engage corresponding apertures 536 in the ridge cap members ( FIG. 15 ). The length of each ridge cap corresponds to the width of a roof panel.
All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.
It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein.
One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims. | The present invention provides a system which includes injection molded roof panels, header assemblies and ridge caps having integrated connectors which combine to form a family of variously sized roof assemblies for utility enclosures. The injection molding facilitates integrally formed connectors so that the roof panels, header assemblies and ridge caps interlock with one another without the need for separate connectors. | 4 |
RELATED APPLICATIONS
[0001] This application is related to U.S. Provisional Application Ser. No. 60/912,614 filed on Apr. 18, 2007, and takes priority therefrom.
BACKGROUND OF THE INVENTION
[0002] As is well-known, many species of animals and birds are raised and/or kept by people for various purposes, e.g., as pets; for the production of valuable products such as food or furs; or for experimental purposes. A major problem connected with the raising and/or keeping of animals is the disposition of their waste excretions, mainly urine and feces. Whether the animal or bird is caged, in which case its waste is deposited on the floor of the cage, or allowed to roam free but is trained to deposit its waste in a particular receptacle, a “litter” material is generally employed which is capable of absorbing the liquid portion of waste excretions, primarily urine and the excess liquid of fecal matter.
[0003] The most commonly used litter box absorbent materials are inexpensive clays, such as calcined clays, that are safe and non-irritating to the animals, and that absorb relatively substantial amounts of liquids. Other porous, solid litter box absorbent materials, that are used alone or in combination, include straw, sawdust, wood chips, wood shavings, porous polymeric beads, shredded paper, sand, bark, cloth, ground corn husks, cellulose, and water-insoluble inorganic salts, such as calcium sulfate. Each of these absorbent materials has the advantage of low cost, but each suffers from the disadvantage of merely absorbing a liquid waste product and holding the product within its porous matrices, or, in the case of sand, absorbing the liquid dross on its surface. For each absorbent material, offensive odors are eventually caused by the absorbed urine, and the entire contents of the litter box, including soiled absorbent material and unsoiled absorbent material, has to be discarded.
[0004] In order to reduce or eliminate objectionable odors, homeowners periodically remove the fecal matter from the litter absorbent physically. However, physical removal of the feces does not reduce or eliminate odors caused by the urine absorbed into the absorbent. Therefore, when the odors caused by the absorbed urine become intolerable, the homeowner discards the litter box absorbent material entirely. The homeowner then washes the litter box and refills the litter box with fresh litter box absorbent material. These activities are unpleasant, time-consuming and expensive. Consequently, the litter box absorbent material usually is a relatively inexpensive solid absorbent material, such that an individual cleaning of the litter box is not particularly economically burdensome. However, repeated litter box cleanings over a period of time accounts for relatively large expenditures.
[0005] Of particular interest as the basic component of animal litters are the clayey soils or comminuted rocks, e.g. the bentonites, comprising at least one water-swellable clay mineral, e.g., montmorillonite, since these materials have the ability to clump and harden after contact with an aqueous liquid such as urine. This facilitates the removal of only the soiled portion of the litter in a litter box or cage during cleaning without the necessity of removing all the litter.
[0006] Many clumping animal litters are made from clays and other mineral substrates. Such litters typically include particles of a mineral substrate, which substrate functions as an absorbent and/or odor reducer. The particles may be coated with a liquid-activated adhesive material, such as gelatinized starch, on the surfaces of the particles. When wetted, the adhesive material is activated and causes the discrete litter particles to agglomerate into clumps.
[0007] Although clay-based litters may be functional as clumping animal litters, such litters suffer from certain drawbacks. For example, one disadvantage of clay litters is the high density of the clay component of the litter. Because of this high density, a heavy mass of litter must be used for a given volume of urine. The resulting clumps of spent litter are somewhat heavy, and thus can fracture in the absence of strong interparticle adhesion. Another disadvantage of clay litters is that, because the clay is not biodegradable, the litter cannot be flushed into some sewerage systems after use. This may be inconvenient for certain animal owners.
[0008] Clumping litters made from bentonite were introduced in 1989, providing better and longer lasting odor control than did traditional litters. Bentonite is a swelling mineral of the clay category, with a unique ability to gel and agglomerate when wetted, creating scoopable clumps. However, mineral based clumping litter are heavy and dusty. While their innate absorption, clumping, and odor control attributes are good, further performance improvement by solid and/or liquid additives is limited.
SUMMARY OF THE INVENTION
[0009] A light density clay granule useful for a litter material is provided by treating the clay with an electrolyte solution and then heating at elevated temperatures sufficient to increase the porosity of the clay granule. Substantial reduction in the bulk density of the clay granules has been achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The FIGURE is a photograph of a sodium bentonite clay which has been treated by the process of this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0011] The raw clay which can be treated in accordance with the process of this invention can include any clay useful to adsorb liquids and for use as a litter material. The raw clay can be from either the hormite mineral group (a hormite clay), the kaolinite mineral group (a kaolinite clay), or the smectite mineral group (a smectite clay). The hormite group of minerals includes the palygorskite and sepiolite varieties which have silicate ring, ribbon, or chain structures. The kaolinite group includes kaolin, halloysite, and dickite. The smectite mineral group includes the montmorillonite, vermiculite, nontronite, hectorite, and saponite varieties. Other minerals which are neither hormite, kaolinite, nor smectite which may be present in the raw clay are opal, apatite, calcite, feldspar, mica, quartz, and gypsum among others.
[0012] Preferred clay mineral may be, for example, a montmorillonoid or smectite, having a three-layer, sheet structure crystal lattice with two layers of silicon/oxygen tetrahedrons between which is a central layer of aluminum and/or magnesium/oxygen dioctahedrons or trioctahedrons. Part of the silicon in the tetrahedral layers may be substituted with aluminum and part of the aluminum and/or magnesium in the central octahedral layer may be substituted with other elements such as lithium, chromium, zinc, or iron. Contemplated montmorillonoid clay minerals are montmorillonite and nontronite containing a dioctahedral central layer, and hectorite, saponite, and sauconite containing a trioctohedral central layer.
[0013] When the foregoing montmorillonoid clay minerals are contacted with water or water vapor, the water molecules penetrate between the layers causing interlayer or intracrystalline swelling and expansion of the entire lattice. This causes the particles of clayey component in the animal litter to agglomerate thus facilitating the removal of only that portion of the litter which is swelled by urine or other aqueous waste liquid.
[0014] The clayey component may have a particle size in the range, for example, of about 300 to 2500 microns (about 50 to 8 U.S. mesh size), preferably about 420 to 840 microns (about 40 to 20 U.S. mesh size).
[0015] The preferred clayey component of the animal litter of the invention is a comminuted bentonite, more preferably a sodium bentonite, which contains a preponderant amount of montmorillonite clay mineral.
[0016] The metal salt that serves as the agent for reducing the bulk density of the clay method is supplied as in the form of an aqueous solution. Preferably, the metal salt is an alkali metal salt, alkaline earth metal or ammonium salt. The preferred alkali metal salt is selected from the group consisting of sodium carbonate, sodium bicarbonate, sodium chloride, lithium chloride, potassium carbonate, potassium chloride, sodium orthosilicate, and sodium metasilicate. More preferably, the alkali metal salt is sodium carbonate. The preferred alkaline earth metal salt is a member of the group consisting of calcium formate, calcium chloride, and magnesium chloride. Also, it is preferable that the metal salt is thermally decomposable.
[0017] In general, the metal salt or electrolyte is added to the clay material as an aqueous solution. When using an aqueous solution of the metal salt, the metal salt content of the solution is in the range of from about 5 to about 30% by weight of the salt and water. Typically, the metal salt content of the solution is from about 10 to 20% by weight. The clay granule is treated with the aqueous solution in general by soaking the clay granule in the aqueous solution. Other methods of treating the clay material with the aqueous solution can be utilized besides immersion. Thus, a spray process, drip process, or even a mixing process can be utilized. Typically the amount of aqueous solution of the metal salt is applied to the clay at a level in the range from about 40 to 1,000% by weight. The time the aqueous solution is in contact with the clay granules can be adjusted to ensure sufficient incorporation of the electrolyte into the pores of the clay granule. Thus, in a method in which the clay granules are immersed in the aqueous solution, a time for treatment can range from about 1 to 30 hours, with soaking times of between 10 and 25 hours being particularly useful.
[0018] The metal salt impregnated clay can be heated in a muffle furnace or in a rotary kiln to a temperature in the range from about 600° C. to 1,200° C. A particular useful temperature ranges from about 750-950° C. This temperature is maintained for a time period of from about 1 to 5 hours. A time period of from about 1 to 3 hours being particularly useful. What results is a clay particle which has a substantially reduced bulk density from the starting material. Thus, reductions in bulk density from at least about 10%, and typically, at least about 40% and higher have been achieved. Please see the FIGURE which shows the bentonite granule after being treated in accordance with this invention. Thus, the density of an untreated sodium bentonite will range from about 910-980 gm/liter, whereas the sodium bentonite treated in accordance with this invention will have a bulk density of less than about 750 gm/liter with bulk densities of from about 500-650 gm/liter being typical. Importantly, it has been found that the absorption of the puffed bentonite of this invention is increased, e.g. doubled, over the absorption of the untreated material.
Example
[0019] Sodium bentonite was first treated in one of three different ways:
1) No treatment 2) Soaked with a water mist from a spray trigger, where particles were visibly darkened and all water was completely absorbed by the particles. The sample was allowed to sit in air for about 10 minutes 3) Soaked for 16 hours in a 10% (wt./wt.) aqueous solution of NH4Cl (50 g of bentonite soaked in 200 g of solution)
[0023] Approximately 2.3 g of each sample (with treatments 2 and 3 being wet) were placed in 50 mL ceramic crucibles. The samples were then placed in a muffle furnace at 850° C. for 2 hours. The samples were then removed and allowed to cool to room temperature for about 16 hours. The samples were exposed to ambient air during cooling.
[0024] Original (natural) density of Sodium Bentonite=0.9-1.0 grams/cm 3
[0025] Density of Samples 3=10% Aqueous Ammonia Chloride Solution Treated Bentonite=0.4 grams/cm 3
[0026] Density of Samples 2=Water Treated Bentonite=0.8 grams/cm 3 .
[0027] Absorption for the untreated sodium bentonite=0.43 mg urine/gm of litter.
[0028] Absorption for the puffed bentonite=0.81 mg urine/gram of litter. | An animal litter such as a clay material is treated to reduce the bulk density thereof by contacting the clay material with an aqueous electrolyte solution and then heating at an elevated temperature. Substantial reductions in bulk density have been achieved without reducing the absorption capacity of the clay granule. | 0 |
FIELD
[0001] The embodiments of the invention disclosed herein relate to recovery of equipment used in oil production. More specifically, the embodiments of the invention relate to the methods of metal treatment, more particularly to methods of remanufacturing used standard length rods, particularly pump rods typically used in the mechanized oil deep-pumping extraction.
BACKGROUND
[0002] A sucker rod is a rigid rod used in the oil industry to join together the surface and downhole components of a reciprocating piston pump installed in an oil well. These rods are typically between 25 and 30 feet (7 to 9 meters) in length, and threaded at both ends.
[0003] Prior art discloses a method of hardening rods such as sucker rods with the help of a device with two heads that have the ability to clamp two ends of the rod in need of treatment or modification. See Russian patent RU 2082590. In this embodiment, typically one head turns uncontrollably with the rod treated along its longitudinal central line. Unfortunately, use of the aforementioned device can result in deformation of standard length sucker rods due to tension and torsion, even though cold working the rod's surface would improve the fatigue strength and the efficiency. Additionally another shortcoming of this known method lies in the fact that this device method will not reclaim the proper geometric shape of the rod and eliminate the inner stress in it, which deteriorates the quality of the remanufactured rod and its service life.
[0004] Additional methods of remanufacturing sucker rods for re-use is to eliminate the fatigue stress in the used rods by a method involving thermally treating the rods at a temperature between about 200° C. and about 650° C. for 15 to 30 minutes. It consists of normalization, upgrading or tempering, with reference to the material or rods remanufactured. After thermal treatment the rods are straightened while still hot to achieve the required straightness. Additionally, straightening while still hot allows for the removal of stress which can occur otherwise during the course of the straightening procedure.
[0005] Typically, in such implementation, the rods undergo shot peening. Shot peening is a cold working process used to produce a compressive residual stress layer and modify mechanical properties of metals. It entails impacting the surface of a metal with shot (round metallic, glass, or ceramic particles) with force sufficient to cause plastic deformation. The shot peening process used on the reclamation of sucker rods removes scale, localizes micro-cracks and improves fatigue strength.
[0006] However, the shortcomings of this aforementioned method lie in the fact that worn out or corrosion damaged rods still retain all outside geometrical form defects, even after thermal reclamation.
[0007] It would therefore be desirable to create a more efficient method for remanufacturing standard length rods such as sucker rods that would make it possible to improve the quality of the products and decrease defects as compared with the reclamation processes delivered by traditional methods.
SUMMARY
[0008] Certain embodiments of the invention pertain to a method for reconditioning a used sucker rod having a given diameter. In such embodiments the method may comprise the steps of: 1) obtaining a used sucker rod; 2) removing contaminates from the surface of the sucker rod; 3) performing a non-visual inspection of the used sucker rod to determine if the sucker rod is amenable to reconditioning; 4) categorizing the sucker rod into a steel classes; 5) heating the rod until the sucker rod is able to undergo plastic deformation; 6) shaping the rod at a temperature wherein plastic deformation occurs; 7) cooling the rod; and 8) cutting the rod into a desired length.
[0009] In embodiments pertaining to cleaning the sucker rod, the method may comprise: washing the sucker rod with an organic compound, pressure washing the sucker rod, blasting the sucker rod with dry ice, or a combination thereof. In embodiments wherein washing the sucker rod in an organic compound is contemplated, the organic compound may be kerosene.
[0010] In embodiments pertaining to a non-visual inspection of the used sucker rod, the method may comprise performing a magnetic flux leakage inspection of the sucker rod.
[0011] In embodiments pertaining to categorizing the sucker rod, the method may comprise assigning the sucker rod a steel class such as Class C steel, Class D steel, Class KD steel and High Strength steel.
[0012] In embodiments pertaining to the heating of the rod, the method may comprise heating the sucker rod to a temperature between about 900° C. and about 1300° C. Still further, said heating of the sucker rod may be accomplished by induction heating.
[0013] In embodiments pertaining to the shaping of the rod, shaping may decrease the diameter by one standard size, the standard sizes being 1″, ⅞″, ¾″, and ⅝″, and increases the length of the rod. Alternatively, shaping may decrease the diameter by more than one standard size. In either embodiment, the rod length is increased. In embodiments wherein the diameter has decreased by a single size, the rod may be cut into a shorter rod for use as a sucker rod and a pony rod. In embodiments wherein the diameter has decreased by more than one size, the rod may be cut into two or more rods for use as sucker rods.
[0014] In further embodiments, after shaping the rod, the rod is subjected to shot peening.
[0015] In further embodiments, after cutting the rod, ends are forged onto the rod to generate a new sucker rod.
[0016] In further embodiments after cutting the rod, the rod is subjected to a final inspection such as an eddy current inspection.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a flow chart of an embodiment of a method of reconditioning sucker rods, and wherein solid arrows are generally required and dashed arrows are optional.
LIST OF REFERENCE NUMERALS
[0018] collection process 1
[0019] shipment process 2
[0020] presortment 3
[0021] discarding process 4
[0022] grade sortment procedure 5
[0023] C 6
[0024] D 7
[0025] KD 8
[0026] High Strength 9
[0027] cleaning procedure 10 .
[0028] rod straightening machine 11
[0029] induction furnace 12
[0030] pressure machine 13
[0031] shot peening 14
[0032] cutting procedure 15
[0033] final inspection process 16
[0034] outside manufacturer 17
[0035] factory forging 18
DETAILED DESCRIPTION
[0036] Introduction
[0037] The particulars shown herein are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of various embodiments of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for the fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.
[0038] The following definitions and explanations are meant and intended to be controlling in any future construction unless clearly and unambiguously modified in the following examples or when application of the meaning renders any construction meaningless or essentially meaningless. In cases where the construction of the term would render it meaningless or essentially meaningless, the definition should be taken from Webster's Dictionary 3rd Edition.
[0039] As used herein, the term “sorting” means to arrange according to class, kind, and/or size; to classify.
[0040] As used herein, the term “rod” may include hollow or solid rods, continuous rods or joints, and includes welded, flanged, screwed, and other rod goods. In particular, sucker rod joints are one type of rod which may benefit from the methods described herein, but the disclosure is not so limited.
[0041] As used herein, the term “used rod” means a rod that has been in actual service for a purpose, such as transporting fluids, connecting a downhole pump to a surface driver, and the like, whether on the surface, downhole, underwater, on-shore, or off-shore. In particular, in the case of sucker rods, used sucker rods are those that may be lifted to a holding area where they are uniquely identified according to size, quantity, company name and well location and tagged appropriately.
[0042] As used herein the phrase “performing non-visual, non-destructive inspection” means a technique which does not impair the rods from performing their intended function or use, and does not involve a human visual test.
[0043] It is a goal of the present invention to remanufacture standard sized rods such as sucker rods by methods which include reheating of the rod body up to a particular temperature and applying pressure in conditions favorable for plastic deformation.
[0044] Still further, it is a goal of the present invention to clean the rod devices. Following cleaning, it is a goal of the present invention to presort the rods, such as sucker rods by grade and quality. Following assortment, the methods disclosed herein contemplate cleaning the rod devices. Following cleaning, the methods disclosed herein contemplate straightening the rod devices. Following straightening the rod devices, the methods disclosed herein contemplate subjecting the rod devices to heating to the point wherein plastic deformation may occur and pressure for shaping. Following the heating process, the methods disclosed herein contemplate subjecting the rod devices to a rolling mill. Following subjecting the rod devices to a rolling mill, the methods disclosed herein contemplate straightening the rods again if necessary.
[0045] Cleaning
[0046] Typically, before inspection to sort out unacceptable rods from rods which are able to function for their intended purpose, the rods are cleaned. Typically, in most embodiments of the invention, the used rods are cleaned in a hot kerosene bath to remove paraffin, grease and other foreign materials.
[0047] However, in certain embodiments the cleaning process may be to subject the rods to pressure washing, either with water or with other solvents such as inorganic solvents such as acid baths and the like or organic solvents. Organic solvents contemplated may include benzene, ether, gasoline, acetone and the like. Further, it is contemplated that in some embodiments, the cleaning process with certain organic or inorganic solvents may not require the solvents to be blasted against the rods via pressure washing but rather the rods may be dipped, submerged, or subject to low pressure wetting of such solvents in order to clean the rods.
[0048] In other embodiments, high pressure air, high pressure inert gases such as nitrogen, or the noble gasses may be used to clean the rods of paraffin, grease and other foreign materials.
[0049] In still further embodiments, the rods may be shot blasted with sand, polystyrene, glass and the like to remove paraffin, grease and other foreign materials.
[0050] It is further contemplated that dry ice cleaning may be used. In such embodiments, the rod may be subjected to being blasted with dry ice or surrounded with dry ice in order to remove the aforementioned contaminates. A particular advantage of the use of dry ice is the lack of flammability associated with the use of organic solvents such as kerosene, acetone and the like. An additional advantage of dry ice cleaning is the lack of cleanup of the cleaning material as dry ice sublimates at room temperature and normal atmospheric pressure (1 bar). However, it may be necessary to provide adequate ventilation should workers be present in order to avoid carbon dioxide poisoning.
[0051] Once the rods are clean, typically in most embodiments of the invention, they are subjected to presortment.
[0052] Presortment
[0053] Typically, rods are collected from petroleum producing sites and brought to a central location for inspection prior to any reconditioning or remanufacturing processes. Visual inspection is typically the first step in the convention reclamation and reconditioning processes.
[0054] Typically, the process of visual inspection typically involves a person visually locating pitting, corrosion, wear, stretched rods and bent rods. Any rod which fails to pass this visual inspection may be removed from the aforementioned central location as rejected.
[0055] However, despite visual inspection, even clean rods may have unseen defects such as cracks that result in such rods being unacceptable for their intended use. Accordingly, sometimes other methods of inspection are used.
[0056] In many embodiments of the invention, the methods comprise performing non-visual or non-destructive inspection of used rods prior to any straightening as discussed below.
[0057] In order to inspect the rods in a non-visual manner, methods of the invention may include passing used rods through one or more stationary inspection stations. Alternatively one or more inspection apparatus may be moved along stationary rods. Alternatively, both the used rods and inspection apparatus may move.
[0058] In certain embodiments of the invention pertaining to non-visual inspection, magnetic flux leakage inspection may be used. Such methods typically involve the use of a magnetic coil and a detector assembly for inspecting the rods. Such systems typically employ one or more magnetic detectors adapted to be spaced a first distance from the rod member by one or more substantially frictionless members during an inspection. Methods specifically pertaining to magnetic flux leakage inspection may be found in U.S. Pat. No. 7,397,238, which is herein incorporated by reference in its entirety. In alternative embodiments of the invention, other suitable non-visual, non-destructive inspections include, but are not limited to: ultrasonic inspection, eddy current inspection, acoustic emission inspection, and the like. Furthermore, the data from such tests may be presented in one or more formats, including visual format, such as on a CRT screen, flat panel screen, printer, strip chart recorder and the like.
[0059] Additionally, in addition to the detection of flaws, the rods, in certain embodiments may be separated in to grades of steel. In such embodiments, it may be beneficial to determine the grade of the steel rod before any treatment occurs so as to know the physical constraints and properties of the end product. In such embodiments, the grades of steel are typically divided into the following: Class C steel, Class D steel, Class KD steel, and High Strength steel. Within the classes, Class D steel is typically divided by alloy D and carbon D.
[0060] Straightening
[0061] Typically, in many embodiments of the invention, rods that have not been rejected, but that are bent or still possess rod guides are sent to a rod straightening machine and/or a rod guide removal machine. Typically, in many embodiments of the invention, once the rods have been straightened and no longer have rod guides, they may be returned to the aforementioned central location.
[0062] Heating and Shaping
[0063] In certain embodiments of the invention, upon straightening of used rods, the rods are subjected to heating. In such embodiments, a rod such as a sucker rod in need of reclamation is heated to a temperature favorable for plastic deformation of the rod. In the case of steel, the temperature may be within the range of about 900° C. to about 1300° C. This temperature range is known to be used for treating steel alloys through forging, rolling, deformation and the like. Still further in implementation, at the same time the rod is being heated to a temperature favorable for plastic deformation, a hot recrystallization of the rod takes place which eliminates inner stress of the rod that has accumulated during the course of the rod's operational life.
[0064] In certain embodiments the desired geometry of the used rods is obtained by treatment under pressure. In such embodiments, the cross sectional area of the rod may be varied while the standard length of the rod is maintained. In such embodiments, mechanical properties of rods may be enhanced during the pressure treatment such that a rod is structurally stronger in its peripheral zone. For example, by the reheating the rod body up to a temperature which would allow it to undergo plastic deformation under pressure, the rod may be structurally stronger in the peripheral zone as compared to rods treated by other methods of reclamation. Additionally, the high temperature used to make the rod favorable for plastic deformation also allows the rod to be reshaped to the correct geometric form as before without any defects caused in the operations such as cracks or cavities.
[0065] In further embodiments, reheating the rod is specifically achieved through the use of an induction furnace. As is known in the art, an induction furnace is an electrical furnace in which the heat is applied by induction heating of metal. The advantage of the induction furnace is a clean, energy-efficient and well-controllable melting process compared to most other means of metal melting. Since no arc or combustion is used, the temperature of the rod can be set such that it is no higher than what is required to make it amenable to plastic deformation; this can prevent loss of valuable alloying elements. Operating frequencies range from utility frequency (50 or 60 Hz) to 400 kHz or higher, usually depending on the material being melted, the capacity of the furnace and the melting speed required. Generally, the smaller the volume of the melts, the higher the frequency of the furnace used; this is due to the skin depth which is a measure of the distance an alternating current can penetrate beneath the surface of a conductor. For the same conductivity, the higher frequencies have a shallow skin depth, in other words, that is less penetration into the melt. Lower frequencies can generate stifling or turbulence in the metal.
[0066] In still further embodiments, upon heating the used rod to a temperature favorable for plastic deformation, the used rod can be treated under pressure, typically by radial-helical rolling. As a sucker rod or pump rod is an elongated bar shape, under pressure treatment the cross-sectional diameter of the rod will decrease such that the rod can be reformed into the next smaller standard size if desired. After plastic deformation, besides shrinking the cross-sectional area, the length of the rod will be increased if the mass of the metal remains constant or near constant. Typically, the reduction in diameter is one size down in terms of standard rod size.
[0067] However, reduction by several sizes would allow two sucker rods to be produced out of one parent sucker rod. The standard sizes for sucker rods in English measurements are 1″, ⅞″, ¾″, and ⅝″.
[0068] As the heating and shaping increases the length, the rods may be cut before the heating and shaping to remove the ends. Typically processed in one of two ways. In the first way, the rods may simply have the ends cut off so that the rods are cut to the correct length and the remaining steel can be used to make pony rods. Alternatively, the ends can be cut off plus additional footage in the body of the rod in order to produce new bar stock that is the length needed to produce a new sucker rod.
[0069] After treatment via plastic deformation, the rods, such as sucker rods may be raw bar stock that can be sold to users or other manufacturers in the petroleum industry. These rods can be made to a standardized length again by cold chiseling, abrasive cutting or both.
[0070] In this embodiment, the users or other manufacturers may forge the ends of the sucker rods to fit their particular equipment needs. Alternatively, an additional embodiment of the invention may be to forge the ends of the sucker rods at the location of the can be made to a standardized length again by cold chiseling, abrasive cutting or both.
[0071] Shot Peening
[0072] Upon reformation, the rod is then cooled and stored for use or further treatments.
[0073] In certain embodiments, after cooling the rod, such as a sucker rod is subjected to shot peening. Shot peening is a cold working process in which the surface is bombarded with small spherical media called shot. As each individual shot particle strikes the surface, it produces a slight rounded depression. Plastic flow and radial stretching of the surface metal occur at the instant of contact and the edges of the depression rise slightly above the original surface. Benefits obtained by shot peening are the result of the effect of the compressive stress and the cold working induced. Compressive stresses are beneficial in increasing resistance to fatigue failures, corrosion fatigue, stress corrosion cracking, and hydrogen assisted cracking. Shot peening is effective in reducing sucker rod fatigue failures caused by cyclic loading. Stress corrosion cracking cannot occur in an area of compressive stress. The compressive stresses induced by shot peening can effectively overcome the surface tensile stresses that cause stress corrosion. Shot peening has been shown to be effective in retarding the migration of hydrogen through metal. Shot peening improves the surface integrity of the sucker rod. As peening cold-works the rod surface, it blends small surface imperfections and effectively eliminates them as stress concentration points.
[0074] Final Inspection
[0075] In certain embodiments of the invention, following the sorting, cleaning, straightening, heating and shaping of the rods, the rods are subject to a final inspection. Typically such inspection is eddy current inspection. Eddy-current inspection uses electromagnetic induction to detect flaws in conductive materials. In a standard eddy current inspection a circular coil carrying current is placed in proximity to the sucker rod. The alternating current in the coil generates changing magnetic field which interacts with sucker rod and generates an eddy current. Variations in the phase and magnitude of these eddy currents can be monitored using a second receiver coil, or by measuring changes to the current flowing in the primary coil. Variations in the electrical conductivity or magnetic permeability of the test object, or the presence of any flaws, will cause a change in eddy current and a corresponding change in the phase and amplitude of the measured current.
[0076] Implementation
[0077] In implementation of the aforementioned embodiments and methods, and referring to FIG. 1 , rods, hereinafter for simplicity referred to as sucker rods, are collected from upstream petroleum producing sites via a collection process 1 . Alternatively, the sucker rods may be shipped to a common location via a shipment process 2 . The sucker rods are then subjected to presortment 3 . First, the sucker rods are scanned through non-visual magnetic flux leakage inspection to sort out flaws in the sucker rods. Sucker rods which have failed inspection are subject to a discarding process 4 . Sucker rods which have not failed this inspection are subjected to a grade sortment procedure 5 to sort out the grade of steel, such as C 6 , D 7 , KD 8 and High Strength 9 . Sucker rods which have not failed inspection due to extensive cracks or extensive corrosion, and have been sorted are then subjected to a cleaning procedure 10 .
[0078] In a preferred implementation, the sucker rods, separated by grade of steel, are taken to a plant. Each grade of sucker rods is treated in turn. In the plant, the sucker rods are first cleaned.
[0079] After cleaning, each sucker rod in need of straightening is subjected to a rod straightening machine 11 . After straightening, the rods are capable of being heated and shaped.
[0080] In the step of heating and shaping, each rod is placed upon a conveyor which transports each sucker rod through an induction furnace 12 or a series of induction furnaces with a temperature of between about 900° C. to about 1300° C. The heating is designed not to melt the sucker rod but to soften each sucker rod to the point wherein plastic deformation is possible.
[0081] Following heating to the point wherein plastic deformation is possible, the sucker rod is subjected to a pressure machine 13 in order to smooth out any surface imperfections. This process compresses the sucker rod such that the cross sectional area may be changed.
[0082] Upon shaping, the conveyor removes the sucker rod from the pressure machine and the sucker rod is allowed to cool. After cooling, the sucker rod may then be optionally subjected to shot peening 14 . Regardless of whether the sucker rod is subjected to shot peening, the sucker rod may be optionally cut to a desired length through a cutting procedure 15 . When cut to a desired length, the sucker rod is then subjected to a final inspection process 16 . Generally, the inspection process is eddy current inspection. After inspection, the sucker rod is shipped to an outside manufacturer 17 in order to forge end pieces on the sucker rod for appropriate applications. Optionally, factory forging 18 may be done wherein the forging is done at the same location as where the rod is heated and shaped.
[0083] It should be appreciated by those of skill in the art that the techniques disclosed in the aforementioned embodiments represent techniques discovered by the inventors to function well in the practice of the invention, and thus can be considered to constitute preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit or scope of the invention.
REFERENCES
[0084] U.S. Pat. No. 7,985,938
[0085] RU 2082590 | The disclosure relates to the treatment of rods made of metal, particularly to the method of reclamation of used standard length rods, such as pump rods already used in the mechanical deep-pumping extraction of oil, as well as to the product made with the help of the mentioned method. The method of remanufacturing of standard length rods includes the reheating of the rod body to a temperature favorable for the plastic treatment of the rod such as plastic deformation of the rod body under pressure. Such methods allow for the reclamation of rods of the desired geometric form and enhancement of the mechanical properties of the remanufactured rod. The technical outcome of the claimed invention consists in the reclamation of rods of the desired geometric form and enhancement of the mechanical properties of the remanufactured rod. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 09/217,915 filed on Dec. 21, 1998, now U.S. Pat. No. 6,081,260, which is a continuation of application Ser. No. 08/919,760 filed on Aug. 28, 1997, now U.S. Pat. No. 5,864,335, which is a continuation of application Ser. No. 08/333,134 filed on Nov. 1, 1994, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to an information processing system using a coordinate input device and a display, and more specifically to an input-display integrated, pen-input information processing system, which allows the display to be carried like paper and freely laid out on a desk (coordinate input device) and which further permits two or more displays stacked together.
Among conventional input processing systems, which integrate a liquid crystal display and a coordinate input device (tablet) into one unit and can be used like paper, are Japanese Patent Laid-Open No. 88325/1986, UK Patent Application GB 2,193,827A and U.S. Pat. No. 4,730,186. As a conventional example of technique that provides coordinate correspondence between liquid crystal elements and a coordinate input device (tablet), there is Japanese Patent Laid-Open No. 183428/1984 (U.S. Pat. No. 4,646, 073). Further, Japanese Patent Laid-Open No. 36330/1988 discloses a system that allows 90-degree rotations of contents shown on the liquid crystal display, in addition to a normal display, for use with customer services at windows. Japanese Patent Laid-Open No. 73203/1993 offers a system which allows a paper frame to be moved or rotated as desired, bringing the ease of use a step closer to that of paper.
Another example of conventional information processing device, as disclosed by Japanese Patent Laid-Open No. 127714/1990, 15717/1992, and 15725/1992, employs a plurality of displays, each bonded with a tablet, through which information is input and output, to improve man-machine interface performance. Japanese Patent Laid-Open No. 278658/1992 discloses a system which consists of a plurality of liquid crystal display elements capable of both-side display, stacked together like a book, allowing the user to turn over the display elements like pages so that he or she can grasp the entire information in the same way as in a book.
In the above-mentioned conventional arts, the display and the tablet are physically integrated in construction and the relation between display and input is fixed. This construction has some drawbacks as it gives no considerations to the situations where the user may want to remove only a display and carry it freely; where the user may want to put the display at an arbitrary location on the desk (corresponding to the tablet or coordinate input device); or where the user may want to stack a plurality of displays together for a particular use.
In addition to the display and the tablet being integrated, the processing device is also a part of the integrated structure, giving rise to a limit to the reduction of weight and thickness. Further, when a plurality of displays are used, the cost is inhibitingly high.
SUMMARY OF THE INVENTION
The feature of this invention is summarized as follows. In an input-display integrated information processing system, which can be physically separated into a coordinate detection device for detecting information and a display for displaying the information and which allows the display to be located anywhere on the coordinate detection device; the system comprises a layout determining unit which determines a layout of the display on said coordinate detection device; the layout determining unit further comprises a display position coordinate detector that detects where in the coordinate space of the coordinate detection device the display for displaying an information is located; and a coordinate converter that converts the information into display coordinates.
With this invention, because the display and the coordinate detection device are separated, the display position coordinate sensing means first checks where in the coordinate space of the coordinate input device the display is located. Then, based on the check result of the display position coordinate sensing means, the layout sensing means checks to what degree the display is tilted with respect to a standard line in the coordinate input device, and which the front or back of the display is being used. Next, to display a handwriting coordinate detected by the coordinate input device at a position where the handwritten information has been entered, the input-to-display coordinate conversion means transforms the handwriting coordinate into a display coordinate according to the information from the layout sensing means and the display position coordinate sensing means. This processing is performed at all times so that the system grasps all dynamic behaviors of the display. This permits such operations as stacking a plurality of displays. Further, because the display can be separated from the coordinate input device and the processing device, a substantial reduction in thickness and weight can be achieved.
Another feature of this invention is a flat display device which has two sets of liquid crystal display stacked with an opaque sheet interposed therebetween, each consisting of a transparent electrode and a liquid crystal member. This flat display device also includes a controller arranged at its periphery which receives code information representing characters and/or figures entered and position information on these characters and/or figures and thereby performs control to display the characters and/or figures corresponding to the code information and the position information on the liquid crystal display.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an overall external view of one embodiment of this invention;
FIG. 2 is a block diagram showing the configuration of the embodiment of the invention;
FIG. 3 is a schematic cross section showing the structure of a flat display sheet;
FIG. 4A is an example layout of the display of the embodiment of the invention;
FIG. 4B is another example layout of the display of the embodiment of this invention;
FIG. 4C is another example layout of the display of the embodiment of this invention;
FIG. 4D is another example layout of the display of the embodiment of this invention;
FIG. 5 is a schematic diagram showing the conversion from the TB coordinate system to the flat display coordinate system;
FIG. 6A is a schematic diagram showing how it is decided whether the front or back of the display is being used;
FIG. 6B is a schematic diagram showing how it is decided whether the front or back of the display is being used;
FIG. 6C is a schematic diagram showing how it is decided whether the front or back of the display is being used;
FIG. 6D is a schematic diagram showing how it is decided whether the front or back of the display is being used;
FIG. 7A shows an example of system management using a plurality of displays;
FIG. 7B shows another example of system management using a plurality of displays;
FIG. 8 is a schematic diagram showing how the degree of overlap between a plurality of displays is determined;
FIG. 9 is a block diagram showing the software configuration of the embodiment of this invention;
FIG. 10 is a marker coordinate detection processing flow in the embodiment of the invention;
FIG. 11 is a layout detection processing flow in the embodiment of the invention;
FIG. 12 is an input-to-display coordinate conversion processing flow in the embodiment of the invention;
FIG. 13 is an overlap detection processing flow in the embodiment of the invention;
FIG. 14 is an ID detection processing flow in the embodiment of the invention;
FIG. 15 is a display mount processing flow in the embodiment of the invention;
FIG. 16 is a pen coordinate detection processing flow in the embodiment of the invention;
FIG. 17A is a schematic diagram showing how an authentication processing is performed in the embodiment of the invention;
FIG. 17B is a schematic diagram showing how an authentication processing is performed in the embodiment of the invention; and
FIG. 17C is a schematic diagram showing how an authentication processing is performed in the embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
One embodiment of the present invention is described by referring to FIGS. 1 to 17 .
FIG. 1 shows an overall external view of one embodiment of this invention.
The following description assumes that this embodiment is used in a network environment, that the display is physically separate from the coordinate input device and is cordless, that there are a plurality of flat displays (liquid crystal displays) and pens, and that one flat display has a front and a back screen.
Referring to FIG. 1, a network NET is connected with servers SV 1 , SV 2 and pen-input information processing systems DESK 1 , DESK 2 of this invention are taken as clients. Thus, an operator can freely utilize server resources from anywhere in the office. Among possible servers are an input/output device server for printer, scanner and facsimile, a large-capacity file server, a computing server that needs to have a CPU performance, and a network server that serves a network. It is possible to use this system as a single equipment without using the network. The pen-input information processing devices DESK 1 , DESK 2 incorporate a coordinate input device TB that senses the coordinate of a stylus pen.
The pen-input information processing device DESK 1 , as shown in FIG. 1, has a plurality of flat displays SHT 1 , SHT 2 (the number of displays may be one or three although two flat displays are shown), which are provided with two pens PEN 1 , PEN 2 in this instance so that two or more people can work on the same desk. Examples of two or more persons using the same desk may include meetings and customer services at window. It is also possible to use two or more flat displays with only one pen.
If, when working on the pen-input information processing device DESK 1 , the flat displays SHT 1 , SHT 2 are carried onto another pen-input information processing device DESK 2 , the similar work environment can be obtained. For this purpose, the network server (SV 1 or SV 2 ) must be able to discriminate between the flat displays SHT 1 , SHT 2 and serve the same environment as the pen-input information processing device DESK 1 . The coordinate input device of the pen-input information processing device DESK 2 may use the stylus pen PEN 1 or PEN 2 or another pen PEN 3 . In this case, the coordinate input device must be able to identify each of the pens PEN 1 -PEN 3 , which are unique. An example method of uniquely identifying the pens PEN 1 -PEN 3 , as disclosed in Japanese Patent Laid-Open No. 11916/1993, utilizes the difference of their resonance frequencies that are generated by coil and capacitor. Further, the system senses the removal and mounting of the flat displays SHT 1 , SHT 2 to and from the pen-input information processing device DESK 1 to save and recover the work environment. This allows an operator to immediately start his or her work simply by placing the flat displays SHT 1 , SHT 2 on the pen-input information processing device DESK 1 , substantially improving the man-machine interface. Because the pen is of an electromagnetic type, a signal of the pen PEN 1 passes through the flat display SHT 1 , SHT 2 (in the example of FIG. 1) so that the coordinate of the pen can be detected. Once the pen coordinate is detected, handwriting input can be made as well as conventional menu and icon specification.
Next, by referring to FIG. 2, a block configuration of one embodiment of this invention (a case of pen-input information processing device DESK 1 ) is described. The pen-input information processing device consists largely of a processing device DESK 1 (with a built-in coordinate input device) and two flat display sheets SHT 1 , SHT 2 . Information is transferred between the processing device DESK 1 and the two flat display sheets SHT 1 , SHT 2 without using a cord. The flat display sheets SHT 1 , SHT 2 each incorporate a sheet controller SHTC 1 (SHTC 2 not shown), and thus information exchange between the processing device DESK 1 and the display is performed by using code data via cordless interface circuits SHT-M I/F, SHT 1 -S I/F.
The processing device DESK 1 comprises a desk controller DESK 1 C that performs an overall control, a coordinate input device TB, and stylus pens PEN 1 , PEN 2 . The coordinates of the stylus pens PEN 1 , PEN 2 are taken in through an interface TB I/F into the desk controller DESK 1 C for processing. The desk controller DESK 1 C is assumed to have the same processing capability and functions as the latest pen computers and notebook personal computers. Hence, it includes a microprocessor MPU-M, memories (ROM-M, RAM-M), an interface NET I/F with external circuits, and a power supply PWR.
The flat display SHT 1 consists of a sheet controller SHTC 1 , two liquid crystal displays LCD 11 , LCD 12 , and a battery CELL 1 (flat display SHT 2 also has the same configuration). Because there are a front and a back display, the both sides of the flat display can be used like a sheet of paper. The contents displayed are kept from disappearing by the internal battery. The sheet controller SHTC 1 has a function to convert code data of characters and drawings into image information and, like the desk controller DESK 1 C, includes a microprocessor MPU-S 1 , memories (ROM-S 1 , RAM-S 1 ), interfaces with LCD LCD 11 I/F, LCD 12 I/F, and an interface SHT 1 -S I/F with the desk controller DESK 1 C. To determine the layout of the flat display SHT 1 , such as its inclination and whether the front or back is being used, markers S 11 , S 12 , S 13 are embedded in the corners of the display. The marker positions are detected by the coordinate input device TB.
Next, the operation and manipulation of the pen-input information processing device of FIG. 2 is explained. The markers S 11 , S 12 , S 13 of the flat display SHT 1 , as described in Japanese Patent Laid-Open No. 11916/1993, consists of a coil and a capacitor. By utilizing the physical phenomenon that the coil-capacitor element resonates at a particular frequency, it is possible to detect the coordinates of the markers and their identifications. That is, the coordinate input device TB supplies particular frequencies to X- and Y-axis sensor of TB, senses the energy at which the markers resonate, and calculates the coordinates of the markers. The coordinates of the stylus pens can also be detected in the similar way. The resonating frequency of the stylus pen PEN 1 and the resonating frequencies of the markers S 11 , S 12 , S 13 need to differ from each other so that the pen and the markers can be uniquely identified. The coordinate of the stylus pen PEN 1 or PEN 2 is entered through the interface TB I/F into the microprocessor MPU-M, which performs corresponding processing.
Next, how the information is processed by the pen-input information processing device DESK 1 is displayed on the display sheet SHT 1 will be explained. First, the coordinate data of the coordinate input device TB is taken in through the TB I/F and is displayed, through the sheet interfaces SHT-M I/F, SHT 1 -S I/F, as a collection of coordinate points on the liquid crystal display LDC 11 or LCD 12 of the flat display SHT 1 . Character and drawing information generated by the pen-input information processing device DESK 1 is transformed into code information, which is then transferred, along with information on position where they are to be displayed, to the flat display SHT 1 . The flat display SHT 1 translates the code information and position information received into character font data (stored in ROM-S 1 ) and drawing images, and stores them in the display memory ROM-S 1 . The data in the display memory is cyclically displayed through the liquid crystal display interface LCD 11 I/F or LCD 12 I/F on the liquid crystal display LCD 11 or LCD 12 . Further, a variety of information supplied through the network NET from higher systems are taken in through the interface NET I/F and then transferred to the flat display SHT 1 for display. As mentioned earlier, because the flat display in this configuration of the invention incorporates memories, the contents of display can be viewed while the display is carried.
In this embodiment, as mentioned above, the desk controller DESK 1 C that mainly performs information processing and the sheet controllers SHTC 1 -SHTC 2 that mainly perform display processing combine to form a multi-processor configuration. This improves the processing performance, simplifies the interface, and provides greater flexibility because of the display's independence from the pen-input information processing device. As another example of this invention, it is possible to stick the flat display on the front surface of a partition in the office with a clip or magnet for displaying information. Further, data communication may be performed from the pen-input information processing device to change the displayed contents. In this case, however, commands cannot be directly entered into the display. (Only when the flat display is put on the desk, can the command or information be entered.)
FIG. 3 shows the construction of the flat display SHT 1 (same applies to SHT 2 ). The flat display SHT 1 has two liquid crystal displays LCD 11 , LCD 12 bound together with an opaque color sheet CLR 1 interposed therebetween to realize a both-side display (display on both front and rear sides). In the flat display, transparent electrodes form segments and apply a potential to liquid crystals to produce an image by utilizing a phase difference of the liquid crystals with respect to a polarizing plate. Therefore, if two liquid crystal displays are merely stacked together, the effects of an image of the other side will show on the display. For this reason, a separating opaque sheet CLR 1 is disposed between the two LCD displays. The flat display SHT 1 incorporates batteries CELL 11 , CELL 12 as power supplies for the displays and a sheet controller SHTC 1 for controlling the display. The batteries CELL 11 , CELL 12 are a combination of a photocell and a secondary battery, and have a battery capacity large enough to display the display information. If wires are used, the battery can be eliminated because power can be supplied from the desk. The sheet controller SHTC 1 is mounted in the peripheral portion of the flat display SHT 1 , considering a possible degradation of reliability caused by deflection. If the sheet controller SHTC 1 is mounted in a film-like sheet, as realized with the wrist watches and pocket calculators, the ease of use of the display is further improved, approaching that of paper. To determine the positional relation (amount of movement and rotation) of the flat display SHT 1 with respect to the coordinate input device, the flat display SHT 1 is provided with markers S 11 , S 12 , S 13 at its corners.
Next, the positional relation between the marker positions and the flat display SHT 1 is described with reference to FIGS. 4A to 4 D. As shown in these figures, the flat display SHT 1 is physically separate from the coordinate input device and thus can be placed at any desired position on the coordinate input device TB. Further, because the flat display SHT 1 can produce images on both sides, it can be turned upside down. FIG. 4A represents a case where the display's front side shows and its inclination is 0 degree (FRONT 0°), FIG. 4B represents a case where the display shows the front side and its inclination is +90° (clockwise direction is taken as +) (FRONT 90°), FIG. 4C represents a case where the display shows the back side and its inclination is 0° (BACK 0°), and FIG. 4D represents a case where the display shows the back side and its inclination is 90° (BACK 0°). In reality, however, the display is rarely positioned at a 90° inclination but usually put randomly at an arbitrary angle and position.
FIG. 5 explains the coordinate conversion when the flat display SHT 1 is placed at an arbitrary position on the coordinate input device TB. TB's coordinate system has x and y axes and the SHT 1 's coordinate system has x′ and y′ axes, with their origins located at the lower left. The markers S 11 , S 12 , S 13 are located at coordinates (x_S 11 , y_S 11 ), (x_S 12 , y_S 12 ), and (x_S 13 , y_S 13 ), as shown. With respect to the TB coordinate system, the SHT 1 coordinate system is displaced to the coordinate of the marker S 11 and rotated by an angle θ in the + direction. Thus, when the coordinates entered from the TB are to be located on the flat display SHT 1 , this coordinate conversion must be performed. The angle of rotation θ can be determined easily from the coordinates of the markers S 11 , S 12 (detail will be given later).
FIGS. 6A to 6 D explain the method of determining which of the front and back of the flat display SHT 1 is being used. The front/back decision can be made by newly adding the coordinate of a marker S 13 . That is, the coordinate of the marker S 11 (x_S 11 ′, y_S 11 ′) is moved to the origin of the TB coordinate system, and the SHT 1 coordinate system is rotated until the coordinate of the marker S 12 (x_S 12 ′, y_S 12 ′) reaches a specified base position (x_S 12 B, y_S 12 B). A check is made to see if the coordinate of the marker S 13 (x_S 13 ′, y_S 13 ′) is located at a specified base position (x_S 13 B, y_S 13 B), thus making the front/back decision. FIG. 6B shows the result of performing the displacement and rotation processing on the flat display SHT 1 put in a state shown in FIG. 6 A. In this case, because the coordinate of the marker S 13 (x_S 13 ′, y_S 13 ′) is at the specified base position (x_S 13 B, y_S 13 B), it is decided that the front side shows. FIG. 6D shows the result of performing the displacement and rotation processing on the flat display SHT 1 put in a state shown in FIG. 6 C. In this case, the coordinate of the marker S 13 (x_S 13 ′, y_S 13 ′) is not located at the specified base position (x_S 13 B, y_S 13 B) and it is decided that the back side shows.
Next, the operation of physically stacking a plurality of displays, one of the features of this invention, will be described by referring to FIGS. 7A and 7B. FIGS. 7A and 7B represent a case where the invention is applied to system management. Although this embodiment uses two sheet displays, more sheet displays can be used. If two flat displays SHT 1 , SHT 2 are provided, the flat display SHT 1 may be assigned to work and the other flat display SHT 2 to a system management, greatly enhancing the flexibility and ease of use. In the conventional system, one screen is divided into multiple windows, which necessarily reduces the window size and results in many overlaps between windows. This situation makes the multiple windows very awkward to use, far from the level of flexibility the paper offers. The present invention eliminates this drawback by using a plurality of flat displays, allowing an operator to use the displays in much the same way as he would sheets of paper. In FIG. 7A, the flat display SHT 1 , in this instance, is used for preparing a document by using a word processor function (it is assumed that the flat display SHT 1 is already assigned a word processor function before starting the work). When one wishes to mail the document to other person (via facsimile), he or she simply stacks the system management display SHT2 on the first display, as shown in FIG. 7B, and picks the icon of mail with a pen. This permits document mailing as with the conventional system. Similarly, a variety of application software (graph generation, table calculation, database, etc.) can be assigned to the work display SHT 1 and managed by the system management display SHT 2 . In the example of FIG. 7A and 7B the system menu (a plurality of functions) is assigned to one display. If, however, the display has only one function (facsimile function, for instance), there is no need to specify the function with a pen and simply stacking the function display on the work display enables facsimile transmission or reception. By assigning an attribute to each flat display and managing the attributes in this way, the displays can be used as ones with a dedicated function, greatly improving the work environment.
If the fundamental operation consists in stacking a plurality of flat displays, it is necessary to prevent erroneous stacking as the number of flat displays increases. For this purpose, it is preferred that an overlapping area A be calculated and compared with a threshold value as shown in FIG. 8 . The overlapping area can be calculated easily from the markers' coordinates and the coordinates where the sides of the two displays cross each other. When displays are stacked together, which of the displays is on the other cannot be known from the markers' coordinates alone. Therefore, in this invention the stacking operation requires the operator to lift the display slightly and place it again on other display. The display that detects this action is recognized as being the topmost. Other possible methods of determining the stacking order include one that uses a coordinate input device that can sense the height direction of coordinate, and one which arranges optical sensors at the corners of the display and determines the stacking order from the presence or absence of signals from the sensors.
Next, the software configuration in this embodiment is described by referring to FIG. 9 . In this figure, software consists largely of a driver software DRV, a middle software MP and application software AP. In the server configuration shown in FIG. 1, a variety of functions may be used and thus the explanation on the functions referring to FIG. 9 is omitted in the following description. They will be explained as required.
First, let us turn to the driver software DRV. Programs DRV 10 -DRV 90 are running at all times to monitor the relation of the display with the coordinate input device, continuously checking display behaviors such as separation, mounting and inclination actions, and performing necessary processing. Signals from the markers S 11 -S 13 and from the stylus pens PEN 1 , PEN 2 are processed by the coordinate input device TB to determine their coordinates. The coordinate data are fed to a display arrangement (marker) coordinate detection processing DRV 10 , a layout detection processing DRV 20 and a pen coordinate detection processing DRV 110 .
The output data from the display arrangement (marker) coordinate detection processing DRV 10 is supplied to the layout detection processing DRV 20 and an overlap detection processing DRV 40 to determine the arrangement and overlapping condition of the flat displays. The arrangement data (inclination angle, displacement and use of front or rear LCD) is processed by an input-to-display coordinate conversion processing DRV 30 and used for displaying handwriting and for pointing displayed objects. The overlapping condition is used by the middle software MP for system management (mailing and file management).
An ID detection processing DRV 50 is a processing to detect identification information unique to the flat displays SHT 1 , SHT 2 by taking in (predefined) IDs stored in the memory of the flat displays SHT 1 , SHT 2 . Only when three conditions are met—ID is detected, display mount information becomes turned ON and the result of a authentication processing DRV 80 is correct—is the program, which was saved, restored by a restore processing DRV 60 , allowing the operator to enter into the environment in which the previous processing was being performed. Normally, this function is identical with what is called a resume function which, at turning power on, brings the system to the previous state (before power was turned off). If, when the flat display is moved to other desk, the ID and the program restore processing fail to match, this is informed to the server, which then downloads the correct environment. This function is executed by the network server.
The coordinate data of the pen coordinate detection processing DRV 110 is converted into character codes and edit command codes by a window management MP 30 , a handwritten character recognition processing DRV 120 and a handwritten editing symbol recognition processing DRV 130 . Handwriting and characters are processed by a display processing DRV 100 and converted into image data.
The application software AP includes, as shown in the figure, a word processing AP 10 for generating a document, a drawing processing AP 20 for drawing figures, a spreadsheet processing AP 30 for calculating numerical data, and a database processing AP 40 for database search and file generation. Any further application software can be used.
By referring to FIGS. 10 to 17 D, the driver software DRV of FIG. 9, a feature of this invention, will be explained.
FIG. 10 shows a flow of the marker coordinate detection processing DRV 10 . In the figure, the marker coordinate detection processing DRV 10 outputs the marker coordinates only after all the markers are detected in order to avoid an unstable state that occurs when the flat display begins to be mounted on the coordinate input device TB.
FIG. 11 shows a flow of the layout detection processing DRV 20 . First, the coordinate of the marker S 11 is moved parallelly to the origin of TB without being rotated (step DRV 20 - 10 ). Next, the angle of rotation θ is calculated, as shown in step DRV 20 - 20 , from the base coordinate of the marker S 12 (x_S 12 B, y_S 12 B) and the S 12 coordinate (x_S 12 ′, y_S 12 ′) after parallel displacement. The base coordinate is a coordinate when the inclination is zero. Next, after the inclination angle θ is calculated, the base coordinate of the marker S 13 is rotated through θ and the coordinate at this time is taken as (x_S 13 ″, y_S 13 ″) (step DRV 20 - 30 ). Finally, a comparison is made between the coordinate of the marker S 13 after parallel displacement (x_S 13 ′, y_S 13 ′) and the base coordinate after rotation (x_S 13 ″, y_S 13 ″) (step DRV 20 - 40 ). If they agree, it is decided that the front side of the display is being used. If not, the back side is used.
FIG. 12 shows a flow of the input-to-display coordinate conversion processing DRV 30 . This flow converts the TB coordinate system to the flat display coordinate system. First, a check is made as to whether the front or back of the display is being used. If the back is used, the coordinate is changed (step DRV 30 - 10 , DRV 30 - 20 ). Next, as shown in step DRV 30 - 30 , the TB coordinate entered is converted into the display coordinate. As a result, the input position and the display position agree, allowing drawings to be displayed and pointing to be performed.
FIG. 13 is a flow of the overlap detection processing DRV 40 . First, the marker coordinates of the flat displays SHT 1 , SHT 2 are taken in (step DRV 40 - 10 , DRV 40 - 20 ). Next, by using two displays' coordinates, an intersection coordinate of each side is calculated (step DRV 40 - 30 ). From the intersection coordinates and the marker coordinates, an overlapping area A is calculated (step DRV 40 - 40 ). Finally, when the overlapping area A is greater than the specified threshold value, a system management enable signal is output (step DRV 40 - 50 , DRV 40 - 60 ). The presence of this system enable signal and of menu or icon specification results in an operation of the system (e.g., copying or mailing of a file).
FIG. 14 is a flow of the ID detection processing DRV 50 . This processing detects an ID unique to a flat display by issuing a request command (step DRV 50 - 10 -DRV 50 - 30 ).
FIG. 15 is a flow of a display mount detection processing DRV 70 . This processing detects when the flat display leaves the TB and when it is mounted on it. The processing turns off a display mount signal when the display is lifted from the TB, i.e., if the AP processing is being performed and at the same time any one of the markers is not detected. Conversely, the display mount signal is turned on when the AP processing is not being performed and at the same all the markers are detected. The mounting order of two or more displays can easily be detected by managing the switching history of the display mount signal for each display.
FIG. 16 is a flow of the pen coordinate detection processing DRV 110 . This processing takes in coordinates of a plurality of pens only when there are PEN 1 and PEN 2 signals (step DRV 100 - 10 -DRV 100 - 40 ).
In the embodiment of this invention, because the display can be separated from the coordinate input device, it has portability like paper. Therefore, there are times when security becomes a problem, as when the display is lost or information is inadvertently seen by third persons. For this reason, a security management is required. FIG. 17 is a schematic diagram showing the authentication processing DRV 80 for security management. The authentication processing may use an input of a pass word or a signature or a combination of both. In this embodiment, the authentication processing using a signature input will be described. First, as illustrated in FIG. 17, the display screen has a viewing area and a non-viewing area. This area definition is carried out by the authentication screen definition processing (not shown in the software configuration of FIG. 9 ). In the viewing area are normally displayed such things as will pose no problem in terms of security, such as titles of documents or mails. The non-viewing area may contain the contents of documents. When one wishes to view the information contained in the non-viewing area, as shown in FIG. 17B, the operator picks the non-viewing area with a pen PEN 1 . In response to this pen-down operation, a message “Enter your signature” appears. If the entered signature agrees with a registered signature, the information is displayed in the non-viewing area, as shown in FIG. 17 C. If the signature does not agree, the information in the non-viewing area of course does not appear.
The aforementioned embodiment of this invention has the following advantages.
As a first advantage, because the flat display is interfaced with the processing device (including TB) through a non-contact interface means (cordless), the flat display can be mounted at any desired position on the processing device. It is also possible to put the display at an angle when writing as you would paper, improving the man-machine interface.
A second advantage is that because a plurality of flat displays can be used, a first display may be assigned to a word processing work and a second one to a system menu. In this way, it is possible to effectively utilize the display by assigning a desired attribute to the display. This in turn allows the use of a greater area of the display screen. Further, because two or more displays can be stacked together with a variety of functions assigned as desired, they can be manipulated intuitively.
A third advantage is that by checking unique IDs of flat displays, the same work environment can be provided even when a plurality of displays are used or when the displays are moved onto other pen-input information processing device. Further, if the display mount detection means is related to the program save/restore processing, it is possible to directly enter into the environment in which the previous work was being done, by simply mounting the flat display on the desk.
A fourth advantage is that because the behaviors of the display and the coordinate input device are continuously monitored, the system can make quick responses. Hence, it is possible, for example, to make pen-inputs while shifting the display, substantially improving the operability.
Next, other embodiments of this invention will be described in the following.
Although in the first embodiment, the ID is given to the flat display, it may be given to the stylus pen. This offers an advantage that there is no need to carry the flat display and the work can be done anywhere as long as a person holds a pen.
While the flat display of the first embodiment can make the both-side display, it is possible to have the display show information on only one side. In this case, the front/back decision is not necessary, obviating the markers.
In the first embodiment, the layout decision is made by using the markers. The layout may also be detected by monitoring the display from a camera on the desk and performing the image processing. This layout detection method using an image processing, though it has a coarse coordinate precision, can be applied to simple pointing.
Although the first embodiment incorporates the coordinate input device along with the processing device in the desk surface, it may be put on the conventional OA desk in the form of a mat. This avoids replacing the desk with a new one in providing the functions of this invention.
In the first embodiment, the flat display is connected through a cordless interface means to the processing device including the coordinate input device so that the display can be carried. It is also possible to connect them with a cord and a clip so that the display can be separated from the processing device while being written on. Although the second embodiment requires removing the clip when carrying the display, it offers an advantage of being able to tilt the display like paper.
As mentioned above, by checking the positional relationship between the processing device including the coordinate input device and the display, it is possible to freely layout the display on the coordinate input device. It is therefore possible to place the display at an angle on the desk as you would the paper, or to stack two or more displays to assign desired functions to the individual displays, greatly improving the man-machine interface. Further, because the display and the coordinate input device are physically separated, the display can be made thin and lightweight. | The present invention relates to an information processing system using a coordinate detection device and displays, and more specifically to an input-display integrated information processing system which allows the displays to be carried like paper and to be freely laid out and stacked together on a desk (coordinate input device). The system includes a layout determining unit for determining a layout of the display on said coordinate detection device, wherein the layout determining unit further comprises a display position coordinate detector that detects where in the coordinate space of the coordinate detection device the display for displaying an information is located, and a coordinate converter that converts the information into display coordinates. The layout determination is done by using markers attached to three of the four corners of the display. | 6 |
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application claims priority from Russian Patent Application No. 2011148915, filed on Dec. 1, 2011 in the Russian Intellectual Property Office, and Korean Patent Application No. 10-2012-0137282, filed on Nov. 29, 2012 in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference in their entirety.
BACKGROUND
[0002] 1. Field
[0003] Embodiments relate to magneto-photonics and a nanotechnology field, and more particularly, to methods of amplifying magneto-optical effects.
[0004] 2. Description of the Related Art
[0005] Properties and application methods with respect to magneto-photon materials have been researched and developed for many decades (e.g., A. B. Granovskii, E. A. Gan'shina, A. N. Yurasov, Yu. V. Boriskina, S. G. Yerokhin, A. B. Khanikaev, M. Inoue, A. P. Vinogradov, Yu. P. Sukhorukov, Magneto - refractive effect in nanostructures, manganite and magneto - photonic crystals , Radiotekhnika i Elektronika, Vol. 52, No. 9, pp. 1152-1159 (2007)). Magneto-photon materials can be used in making optoelectronic devices, communication systems and a computer technology which are controlled by a magnetic field. Separately, there has also been research conducted on the application of inverted opals based on metals and alloys with respect to magnetoplasmonics, particularly, with respect to the manufacture of plasmon circuits.
[0006] The magneto-optical effects created by rotating a polarization plane of a light beam that is transmitted through a transparent medium in a magnetic field (Faraday effect) or reflected from a magnetized medium (Kerr effect) were relevant only in a purely theoretical way for a long time due to small values of rotation angles of the polarization plane. However, in recent decades, important and practical applications have been found. Recently, interest with respect to the magneto-optical effects has increased due to their applications in the fields of physics, optics and electronics.
[0007] A feature of the magneto-optical effects is non-reciprocity, i.e. a disturbance of a reversibility principle of a light beam. A change in a reverse direction of the light beam results in the same rotation angle of a polarization plane in the same direction on a “forward” trajectory. Therefore, the magneto-optical effects are accumulated by repeatedly transmitting the light beam that passes through a magnetic material. Multiple reflections of the light beam in a medium are possible because of a dielectric constant of a material which is spatially modulated. The material (that has become recently widely known as a photon crystal) has photon forbidden zones which occur due to repeated Bragg reflection of electromagnetic waves on a periodic disturbance of a dielectric constant and may be used to magnify an interaction efficiency of light with a medium. In this regard, magnetic inverted opals have created interest related to a capability of making optical devices to be controlled by an external magnetic field based on the magneto-optical effects.
[0008] The value of the Kerr effect can be defined as an efficiency of interaction between light and a magnetized material. Although light is strongly reflected from a conductor below a frequency of plasma oscillations, the light penetrates with a depth of a skin-layer that is a limit in which interaction with a material occurs. Here, the frequency of the plasma oscillations may be given, in an SGS system, as ωp≈(4πne2/m)½ where n indicates a conduction electron density, e indicates a charge, and m indicates an electronic mass. Also, the depth of the skin-layer may be δ=c/(2πσμω)½ (σ—specific conductivity). Thus, a plasmon-polarized wave that represents interconnected oscillations of electrons and an electromagnetic field may be on a metal surface, as a result of interaction between the light and the free charge carriers. The plasmon-polarized wave that occurs on the metal surface results in amplification of the interaction between the light and the material. The more the plasmon-polarized wave is effectively generated, the more the Kerr effect is strongly displayed.
[0009] The plasmon-polarized wave on and under the metal surface is defined by Equations 1 and 2.
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,
2
2
ɛ
1
+
ɛ
2
.
(
Equation
2
)
[0010] Here, k p indicates a wave number of the plasmon-polarized wave, ∈ 1 indicates a dielectric constant of a medium on metal (∈ 1 >0, in vacuum ∈ 1 =1), and ∈ 2 indicates a dielectric constant in the metal (∈ 2 <0, |∈ 2 |>∈ 1 ). A modulus of the dielectric constant ∈ 2 of the metal is decreased with growth of a frequency, and the decrease results in deviation of ω(kp) of the plasmon-polarized wave from a linear dependence. However, branches ω(k) for usual light and ω(kp) for the plasmon-polarized wave do not directly cross each other, and thus, it is impossible to achieve an impulse of light k·sin θ=k p that is a requirement to preserve a component in parallel with the metal surface (where θ indicates an incidence angle of a light beam). However, if the metal has a periodic structure with a period G=2 π/d in a k-space (where d indicates a structure period in a direct space) in an X-axis direction, the wave numbers that differ from each other in a value G may be physically equivalent and thus excitation of the plasmon-polarized wave may have a wave number k p that satisfies Equation 3 below.
[0000] k sin θ= k p ±G (Equation 3)
[0011] In a more general case, k·sin θ=k P +mG, in Equation 3, where m indicates an arbitrary integer. In particular, the requirement of Equation 3 may be achieved by a wave length given via Equation 4.
[0000]
λ
Wood
=
d
(
ɛ
1
ɛ
2
ɛ
1
+
ɛ
2
+
sin
θ
)
(
Equation
4
)
[0012] In this case, effective generation of the plasmon-polarized wave on the metal surface leads to a ‘Wood feature’ that is a sharp decrease in intensity of a reflected light which causes a minimum value in a reflection spectrum.
[0013] Thus, there is a theoretical basis for the concept that the magneto-optical Kerr effect may be amplified by making a periodically-structured surface of a magnetic material, in particular, a magnetic inverted opal.
[0014] Recently, several examples with respect to the use of photon-crystal mediums that amplify interaction between light and a medium have been developed. However, these examples are restricted by the use of photon crystals in refracting optics, whereas the technology of reflecting optics based on photon crystals has not been practically developed. The methods of forming photon-crystal reflecting surfaces, which are applied at present, have insufficient flexibility, and thus do not provide an exact control of surface morphology or a desired application with respect to lithographic approaches which predetermine a complex application of photon-crystal structures as optical components based on reflection that can be controlled by an external field.
[0015] U.S. Pat. No. 7,965,436 discloses a device, performing rotation of a polarization plane of light and method of its manufacturing. The disclosed device is characterized by the following features: the device consists of a nonmagnetic dielectric wave guide and a magnetic shell around the nonmagnetic dielectric wave guide; a nonmagnetic wave guide is the siliceous photon crystal obtained by perforation via a lithographic technology; a thickness of a photon crystal lies within a range from 50 to 400 nanometers, and perforation has a periodic structure along an axis of a wave guide and has a period from 200 to 800 nanometers, and each hole has a diameter from 50 to 100 nanometers; and a device having a length of two micrometers performs circular rotation of a polarization plane of the wave transmitted on the wave guide by 45 degrees.
[0016] The disclosed solution has been chosen as a prototype to be used in a method of amplifying a magneto-optical Kerr effect by using the photon-crystal structures. However, the disclosed solution cannot be applied to amplify interactions between light and a medium at reflection.
SUMMARY
[0017] The exemplary embodiments provide a method of amplifying the efficiency of interactions between light and a medium at reflection, and more particularly, provide a solution to the technical problem on development of a method of amplifying a magneto-optical Kerr effect at reflection on surfaces of magnetic materials.
[0018] According to an aspect of an exemplary embodiment, there is provided a method of amplifying a magneto-optical Kerr effect, the method including operations of fabricating a magnetic photon crystal including a crystal magnet having a periodically-structured surface, and amplifying the magneto-optical Kerr effect by using the periodically-structured surface of the crystal magnet.
[0019] The amplifying of the magneto-optical Kerr effect may be achieved by fabricating a magnetic inverted photon crystal. The magnetic inverted photon crystal may be obtained by structuring a magnetic material on a submicron level as a result of metal electrodeposition in pores of a synthetic colloidal crystal with a period of a structure from 250 to 1900 nanometers with the subsequent removal of the synthetic colloidal crystal. The magnetic photon crystal may be a film with a thickness of 0.1 to 60 micrometers. Also, the magnetic inverted photon crystal may consist of Ni, Co, Fe or alloys containing these metals.
[0020] Surface morphology of the magnetic photon crystal may be determined by a cut level of the closest face-centered cubic packing of microspheres in a plane within a layer of the colloidal crystal.
[0021] A degree of filling metal into the pores of the synthetic opal (i.e., hollows of the colloidal crystal) may exceed 95%.
[0022] Heterogeneity of a cut level of an external layer of the magnetic photon crystal within a layer may not exceed 10% of the structure period in one square centimeter.
[0023] A structure of the magnetic inverted photon crystal may be controlled by using a reflection spectroscopy device during the metal electrodeposition.
[0024] A maximal reflection position in spectrums of the magnetic photon crystal within the range of 300 to 2000 nanometers may be determined by the surface morphology of an external layer of the magnetic photon crystal and may linearly increase with magnification of the cut level of the closest face-centered cubic packing of microspheres within the layer of the colloidal crystal.
[0025] It is noted that the method of amplifying a magneto-optical Kerr effect achieves reflection optics having an improved rotation of a polarization plane under an influence of an external magnetic field. According to an embodiment, a method includes an operation of fabricating the magnetic inverted photon crystal by creating a periodically-structured surface of a magnet, e.g., by using a template method including an operation of filling pores of the colloidal crystal with a magnetic material by performing electrochemical deposition with a spectroscopic control.
[0026] The magnetic photon crystal may have a cut level equal to a structure of a half period of the crystal magnet and thus may achieve over 5-fold amplification of an equatorial magneto-optical Kerr effect.
[0027] The magnetic photon crystal may be a crystal magnet having a structure of a magnetic inverted photon crystal, and the magneto-optical Kerr effect may be amplified by periodically structurizing the surface of the crystal magnet.
[0028] According to an aspect of another exemplary embodiment, there is provided a method of fabricating a magnetic photon crystal, the method including operations of forming a colloidal crystal; performing metal electrodeposition on pores of the colloidal crystal; and removing the colloidal crystal and thus forming a crystal magnet having a structure of an inverted colloidal crystal, wherein a magneto-optical Kerr effect is amplified by periodically structurizing a surface of the crystal magnet.
[0029] According to the method of amplifying a magneto-optical Kerr effect by using photon crystal structures according to the embodiments, it is possible to obtain a magnetic-optical material having a magneto-optical Kerr effect that is amplified at least 5 times, whereby a practical photon crystal device may be achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] The above and/or other aspects will become more apparent by describing in detail exemplary embodiments with reference to the attached drawings in which:
[0031] FIG. 1 shows the scheme of occurrence of a magneto-optical Kerr effect with respect to a structured surface of a magnetic inverted opal in which excitation of localized and delocalized surface plasmons occurs, according to an embodiment;
[0032] FIGS. 2A and 2B show reflection spectrums and Scanning Electron Microscopy (SEM) images of nickel inverted opals, which are obtained while nickel is electro-deposited in pores of a synthetic colloidal crystal, according to an embodiment;
[0033] FIG. 3 shows reflection spectrums and Transverse Magneto-Optical Kerr Effect (TMOKE) spectrums with respect to unstructured films formed of a photon crystal film and nickel which have different thicknesses, according to an embodiment;
[0034] FIG. 4 shows a reflection spectrum and a TMOKE spectrum of a nickel inverted opal film at an incidence angle of θ=50° and a lateral angle ψ=0° and ψ=30°, according to an embodiment; and
[0035] FIGS. 5A and 5B respectively show a reflection spectrum and a TMOKE spectrum of the nickel inverted opal with a cut level of t=0.6 with respect to an incidence angle of θ=45° and various lateral angles ψ=0°, . . . , 30° with step 5°, according to an embodiment.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0036] Hereinafter, embodiments will be described in detail with reference to the attached drawings. In the drawings, like reference numerals in the drawings denote like elements, and the size of each component may be exaggerated for clarity.
[0037] A method of amplifying a magneto-optical Kerr effect by using photon crystal structures according to one or more embodiments may be performed during the fabrication of photon crystals.
[0038] First, a synthetic colloidal crystal is synthesized. The synthetic colloidal crystal may be synthesized by using a method in which polystyrene microspheres or silicon dioxide microspheres (diameter from 200 to 1900 nanometers, distribution by a size no more than 10%) at the application of potential are vertically deposited on a silicon substrate with a sprayed layer of gold having a thickness of 200 nanometers.
[0039] Sample films of the magnetic inverted opals may be formed via electrodeposition by which metal is deposited in pores of the synthetic colloidal crystal. The electrodeposition may be performed at room temperature in a three-electrode cell in a potentiostational mode from neutral electrolytes containing a corresponding device. When hollows of polystyrene colloidal crystals are electrochemically deposited, an ethanol (up to 30%) is added in an electrolyte so as to improve wetting of microspheres of polystyrene. A saturated silver-chlorine (Ag/AgCl) electrode that is connected with a cell via a Luggin capillary is used as a reference electrode. A growth of the magnetic inverted photon crystal is achieved layer-by-layer, and a position of a front of the growth is controlled by a reflection spectroscopy device during metal deposition. When the electrochemical deposition is performed for this purpose, the shooting of a reflection spectrum of a material is performed while an incidence angle of light on a sample is varied from 0 to 45°.
[0040] FIGS. 2A and 2B show reflection spectrums and Scanning Electron Microscopy (SEM) images of a nickel inverted opal film, which are obtained while nickel is electro-deposited in pores of synthesized opals, according to an embodiment. In more detail, FIG. 2A shows a reflection spectrum of a nickel inverted opal during a deposition time in which metal is electro-deposited in hollows of a colloidal crystal film, and SEM images at different growth stages of the nickel inverted opal film. In FIG. 2B , a bold line indicates a typical excessive current while metal is electro-deposited in hollows of a colloidal crystal template. Referring to FIGS. 2A and 2B , an interference pattern that is changed during deposition is observed on the reflection spectrum, and the interference pattern is used to define a cut level of the closest face-centered cubic packing of microspheres in a plane within a layer of the magnetic inverted photon crystal. The heterogeneity of the cut level of an external layer of the magnetic inverted photon crystal on the irradiated area is detected by broadening interference bands.
[0041] The deposition is stopped when a necessary thickness of the magnetic inverted photon crystal is achieved, and microspheres are dissolved in heptane or toluene (in case of the polystyrene colloidal crystal) or an alkali diluted solution (in case of the colloidal crystal of silicon dioxide).
[0042] Since the metal inverted opal according to embodiments has several layers, depth of light penetration and optical properties of such structures differ from properties of the inverted opals made from optically transparent materials.
[0043] FIG. 1 shows the scheme of occurrence of a magneto-optical Kerr effect for the structured surface of the magnetic inverted opal in equatorial geometry with excitation of localized and delocalized surface plasmons, according to an embodiment. In FIG. 1 , a reference number 10 indicates surface (Bragg) plasmons that are excited on a surface of a periodic metal structure, and a reference number 20 indicates localized (Mi) plasmons. The polaritons of the surface plasmons 10 represent oscillations of an electronic gas in a neighborhood of a surface of the metal, penetrating deep into metal on distances of the order of a skin-layer, and the polaritons of the Mi plasmons 20 are excited in spherical hollows in metal. Here, the surface plasmons 10 or the Mi plasmons 20 are excited most effectively depending on morphology of an external surface. Thus, excitation of only the Bragg surface plasmons 10 should occur on a surface of the nickel inverted opal with a cut level t=0.1 (t=d/2R where d indicates a depth of a pore, and R indicates a pore radius), whereas at t=0.9, a prevailing type of plasmons (excited plasmons) is the localized Mi plasmons 20 , and at t=0.6, both of the surface plasmons 10 and the Mi plasmons 20 are excited (refer to FIGS. 3 and 4 ). Also, with respect to various cut levels, a change of an energy position of modes of the Mi plasmons 20 is characteristic, whereas the position of the Bragg surface plasmons 10 remains almost invariable (refer to FIGS. 2A and 2B ).
[0044] The maximum amplification of the magneto-optical Kerr effect is observed at a cut level t=0.5 of an external layer of the magnetic inverted photon crystal at a wavelength of incident irradiation which corresponds to the excitation of Bragg plasmons.
[0045] FIGS. 5A and 5B respectively show a reflection spectrum and a Transverse Magneto-Optical Kerr Effect (TMOKE) spectrum of the nickel inverted opal with a cut level of t=0.6 with respect to an incidence angle of θ=45° and various lateral angles ψ=0°, . . . , 30° with step 5°, according to an exemplary embodiment. Referring to FIGS. 5A and 5B , it is noted that the spectroscopic position of modes of surface plasmons 10 and Mi plasmons 20 depends on both of an incidence angle and a lateral angle of light, which may be used for fine-tuning of a strip of amplification of a magneto-photon effect by the magnetic inverted photon crystals. Magnetic photon crystals with a cut level equal to a half period of a structure are characterized by amplification of a TMOKE more than 5 times.
[0046] The example according to the present exemplary embodiment was achieved by using nickel inverted opals.
[0047] Specifically, according to an embodiment, films of the nickel inverted opals were obtained by electrodeposition in small pores of synthetic opal. Artificial opal was synthesized by a method in which the polystyrene microspheres (diameter d=600 nanometers, distribution by the size no more than 10%) at the application of the potential are vertically deposited on a silicon substrate ( 100 ) with a sprayed layer of gold having the thickness of 200 nanometers. The electrodeposition was performed at room temperature in a three-electrode cell from an electrolyte composed of 0.6M NiSO 4 +0.1M NiCl 2 +0.3M H 3 BO 3 +3.5M C 2 H 5 OH in a potentiostational mode at a potential −0.92 volt. A saturated silver-chlorine (Ag/AgCl) electrode connected with a cell by using a Luggin capillary was used as a reference electrode. The deposition was stopped when a desired thickness of the magnetic inverted photon crystal was achieved, and microspheres were dissolved in toluene.
[0048] Measurement of a magneto-optical Kerr effect was executed in an equatorial geometry, i.e. a change in intensity and a phase of a reflected wave from a magnetized medium occurred at a magnetization vector, perpendicular to planes of incidence and lying in a plane of the sample, made in a variable saturating by amplitude B=1.5 kilogauss magnetic field by a method of synchronous detection on area of ˜2 mm. A value of the TMOKE was defined as the relative change of a reflectivity at magnetization, TKE=(R m −K m )/2R 0 , where R m and K m indicate reflection coefficients of a medium in opposite directions of magnetization, and R 0 indicates a reflection coefficient in conditions that lack an external magnetic field (residual magnetization).
[0049] FIG. 3 shows reflection optical spectrums and TMOKE spectrums with respect to unstructured films formed of a photon crystal film and nickel which have different thicknesses, according to an embodiment. In FIG. 3 , an upper-left image indicates an SEM image of a nickel inverted opal film with a cut level t=0.1, a middle-left image indicates an SEM image of a nickel inverted opal film with a cut level t=0.6, and a lower-left image indicates an SEM image of a nickel inverted opal film with a cut level t=0.9. Also, in FIG. 3 , an upper-right graph indicates a reflection spectrum and a TMOKE spectrum of the nickel inverted opal film with a cut level t=0.1, a middle-right graph indicates a reflection spectrum and a TMOKE spectrum of the nickel inverted opal film with a cut level t=0.6, and a lower-right graph indicates a reflection spectrum and a TMOKE spectrum of the nickel inverted opal film with a cut level t=0.9. Here, an incidence angle θ is 60° and a lateral angle ψ is 0°. In the graphs of FIG. 3 , chain-lines indicate the TMOKE spectrums, i.e., spectroscopic dependences of values of an equatorial magneto-optical Kerr effect of the nickel inverted opal films, and solid lines indicate the reflection spectrums of the nickel inverted opal films. In the graphs of FIG. 3 , a TMOKE spectrum of a non-structured nickel film is illustrated as a black dashed line for comparison.
[0050] Referring to FIG. 3 , the reflection spectrums undergo significant changes during an electrodeposition process as a result of a change in an energy position of modes of both Bragg plasmons 10 and Mi-plasmons 20 with respect to various cut levels. Also, referring to FIG. 3 , it is possible to see that excitation of only Bragg surface plasmons 10 occurs on a surface of the nickel inverted opal with the normalized thickness t=0.1 (t=d/2R where d indicates a depth of a pore, and R indicates a pore radius), at t=0.9, a prevailing type of plasmons are the localized Mi plasmons 20 , and at t=0.6, both surface plasmons 10 and Mi-plasmons 20 are excited. It is apparent via FIG. 3 that amplification of a Kerr effect is observed at photon crystals in connection with excitation of mixed plasmons. Excitation of localized plasmons 20 does not lead to serious changes in values of the equatorial magneto-optical Kerr effect.
[0051] FIG. 4 shows reflection spectrums and TMOKE spectrums of a nickel inverted opal film at an incidence angle θ=50° and lateral angles ψ=0° and ψ=30°, according to an embodiment. The TMOKE spectrums may represent spectroscopic dependences of an equatorial magneto-optical Kerr effect. Null levels of TMOKE values are illustrated as a wavy line. Arrows represent conditions of excitation of delocalized plasmons at lateral angles ψ=0° and ψ=30°. The spectrum reflects an increase of a Kerr effect in the field of Wood's anomaly in comparison with non-structured nickel.
[0052] Thus, the aforementioned method allows an equatorial magneto-optical Kerr effect to be amplified by at least 5 times by using magneto-photon materials.
[0053] In the exemplary embodiments described above, the nickel inverted opal film is formed of magnetic inverted photon crystal. However, according to other embodiments, magnetic inverted photon crystals may consist of Ni, Co, Fe or alloys containing these metals.
[0054] The embodiments provide a photon crystal material with a magneto-optical Kerr effect that is amplified by at least 5 times, and in this regard, the photon crystal material is industrially applicable and can be used in the manufacture of optoelectronic devices to be controlled by a magnetic field.
[0055] While the embodiments have been particularly shown and described, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the embodiments as defined by the following claims. | A method of amplifying a magneto-optical Kerr effect by using photon crystal structures, and a photon crystal having an amplified magneto-optical Kerr effect, and a method of fabricating the photon crystal. The method of amplifying a magneto-optical Kerr effect by using photon crystal structures includes amplifying the magneto-optical Kerr effect by fabricating a magnetic photon crystal including a crystal magnet and using a periodically-structured surface of the crystal magnet. | 2 |
TECHNICAL FIELD
The invention generally relates to retrievable well packers which may be set by wireline and retrieved by tubing string.
BACKGROUND OF THE INVENTION
Well packers utilized for isolating a zone in a well below the packer from a zone above the packer for performing a well service operation such as acidizing, perforating, formation fracturing or pressure containment are known. Further, it is known to initially run a packer downhole to a selected position and to set the packer using wireline apparatus. After setting, the wireline is removed from the well and a tubing string is run down the well and attached to such packers for performing the well servicing operation. The packer can then be removed from the well by manipulation of the tubing string and pulling of the tubing string and packer. The packer can then be redressed and used again in the same well or at another location.
Flow through the packer must be prevented for a time in order to connect the tubing string and often to perform the service operation. In such situations, the packer is essentially used as a temporary bridge plug. Typically, in prior art devices, in order to seal off flow through the packer, a pump-out plug or flow control device is installed below the packer. A pump-out plug is subsequently removed by applying pressure through the tubing string to release the plug from the packer with the result that the pump-out plug is left behind as debris below the packer when the packer is removed. Other prior art devices utilize a flow control device, such as a blanking plug, installed in an accommodating profile at the bottom of the packer and later removed by wireline to allow flow through the packer. However, during service operations or connection of the tubing string, debris can accumulate in the bore of the packer above the blanking plug impairing its retrievability. Accordingly, it is desirable that the flow control device be located at the top of the packer. In known prior art tools, the flow control device is moved to the top of the packer by wireline after the packer is set and the tubing string is attached which requires an additional trip on wireline through the tubing string.
In one specific currently available retrievable packer, a tubular mandrel is connected to a wireline setting device through a wireline adaptor. A pair of slip assemblies and a sealing unit are mounted on the mandrel of the packer to allow the packer to be set in the well casing and to create a seal in the casing isolating a well zone below the packer from a well zone above it. A slick joint is mounted on the top of the mandrel having a plug receiving annular groove. The adaptor includes an elongated rod which is telescoped through the slick joint and a connecting means frangibly secures the bottom the rod in the joint recess where the slick joint and mandrel are threaded. The top of the rod is connected directly to a wireline setting device. A long sleeve attached to the housing of the wireline setting device rests on the top of the packer. A simultaneous application of force from the housing of the wireline setting device, through the sleeve, to the top of the packer in the downward direction and an upward pulling force on the connecting means provides relative motion between the slip assemblies and sealing unit, and the mandrel required to set the packer. However, since the rod extends through the slick joint past the plug receiving annular groove, it is not possible to seat a flow control device at the top of the mandrel.
A similar type of tool is disclosed in Canadian patent 1,286,602. The adaptor disclosed in that patent utilized for setting the packer includes a rod which is telescoped through the tool and frangibly secured to the bottom of the mandrel. In this tool, as in the previous one, the pump-out plug or flow control device must be located beneath the packer because the rod runs through the plug accommodating profile.
SUMMARY OF THE INVENTION
The present invention attempts to overcome the above-noted problems by providing an improved adaptor for use in running and setting a packer on wireline. Specifically, the present invention provides an adaptor, a wireline well packer setting assembly and a method for running and setting a well packer in a well by wireline with a flow control device seated at the top of the packer. More specifically, the present invention provides a unique adaptor enabling a flow control device to be seated at the top of the packer during installation on wireline and setting by a wireline setting device. Thereafter, with the wireline setting device and adaptor removed from the packer, production tubing or the like may be connected to the packer downhole, the flow control device may be removed from the packer by wireline through the tubing, and the packer may be subsequently released and retrieved from the well by manipulation and pulling of the tubing from the well.
Accordingly, the present invention provides an adaptor for use in setting a well packer by means of a wireline setting device with a flow control device removably seated at the top of said well packer and wherein said well packer is of the type including outer packer housings including slip assemblies and a sealing unit, and a tubular mandrel extending there through for relative movement therebetween to anchor said packer to the well casing and to create a seal in said casing, wherein said adapter comprises: (a) a first member engaged with said wireline setting device and an upper packer housing for applying a force in a first direction on said upper packer housing when said wireline setting device is actuated; and (b) a second member engaged with said wireline setting device and said mandrel for applying a force in a second direction opposite to said first direction, when said wireline setting device is actuated; and wherein (c) after said packer is engaged with said well casing and actuated to create said seal continued application of force by said wireline setting device causes said adaptor to disengage from said packer such that said adapter may be completely removed from said packer with said flow control device remaining seated at the top of said packer to inhibit flow through said tubular mandrel.
The present invention further provides a wireline well packer setting assembly for use in setting a well packer of the type including outer packer housings including slip assemblies and a sealing unit, and a tubular mandrel extending therethrough for relative movement therebetween to anchor said packer to the well casing and to create a seal in said casing comprising: (a) a wireline setting device; (b) an adaptor having: (i) a first member engaged with said wireline setting device and an upper packer housing for applying a force in a first direction on said upper packer housing when said wireline setting device is actuated; (ii) a second member engaged with said wireline setting device and said mandrel for applying a force in a second direction opposite to said first direction when said wireline setting device is actuated; (c) a flow control device seated at the top of said well packer; and (d) wherein upon actuation of said wireline setting device, said well packer is engaged with said well casing and actuated to create said seal by relative movement between said packer housings and said mandrel and wherein continued application of force by said wireline setting device on said first and second members of said adaptor causes said adaptor to disengage from said packer such that said adaptor is completely removed from said packer with said flow control device remaining seated at the top of said packer to inhibit flow through said tubular mandrel.
The present invention further provides a method for setting a well packer having a tubular mandrel in the casing of a well by wireline and retrieving said packer by tubing string comprising: (a) removably seating a flow control device adapted to inhibit fluid flow inside the top end of said tubular mandrel; (b) connecting a wireline setting device to the end of a wireline; (c) releasably connecting said well packer to said wireline setting device; (d) running said well packer down said well to a selected position on said wireline; (e) actuating said wireline setting device to set said packer and to thereafter release said packer from said wireline setting device with said flow control device remaining seated at the top end of said packer; (f) connecting a tubing string to said packer; (g) engaging said flow control device by a wireline tool run through said tubing string, for removal and retrieval of said flow control device to allow uninhibited fluid flow through said tubular mandrel; and (h) retrieving said packer when it is no longer required downhole by manipulating said tubing string to disengage said packer and pulling the tubing string and packer to surface.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be further described, by way of example, with reference to the following drawings wherein:
FIGS. 1(a)-1(c) are schematic illustrations of the operating principles of one embodiment of the invention, showing a packer being lowered into the well, being set and being retrieved from the well respectively;
FIGS. 2(a)-2(d) are a cross-sectional and elevational view of a wireline well packer setting assembly and well packer shown as positioned as they would be when run into the well;
FIGS. 3(a)-3(d) are a cross-sectional and elevational view of the wireline well packer setting assembly and well packer with the packer shown installed in the well;
FIGS. 4(a)-4(d) are a cross-sectional and elevational view of the packer attached to a tubing string, the packer being positioned as it would be when it is being retrieved from the well;
FIG. 5 is a schematic illustration of the slip elements and related components of the packer.
DETAILED DESCRIPTION
Referring to FIG. 1 which illustrates one embodiment of the present invention, a packer generally designated 1 is initially attached to an adaptor generally designated 2 which is in turn attached to a wireline setting device generally designated 3. FIG. 1(a) shows the packer 1, adaptor 2 and wireline setting device 3 as they would be when they are being run into the well on wireline (not shown). FIG. 1(b) shows the packer 1, adaptor 2, and wireline setting device 3 as they would be during setting of the packer. FIG. 1(c) shows the packer 1 attached to an on/off tool generally designated 4 which is in turn connected to a tubing string (not shown) with the packer shown disengaged from the well casing for retrieval from the well.
Generally, the packer 1 is run down the well on the wireline adaptor 2 which is in turn connected to the wireline setting device 3 such that, upon actuation of the wireline setting device 3, the packer 1 is anchored and actuated at a selected downhole position as a means of isolating the zone of the well below the packer from the zone above it. In FIGS. 1(a) and 1(b),a flow control device 10 is shown removably seated in a plug accommodating profile in a mandrel 12 of the packer 1. In FIG. 1(c), the flow control device 10 has been removed from the mandrel 12 of the packer 1.
The packer 1 includes the mandrel 12 and a number of outer packer housings including upper and lower slip assemblies 14, 16 and sealing unit 18.
The upper and lower slip assemblies 14, 16 each include slip elements 20 (see FIG. 5) adapted to bite into the inside surface of the well casing 22 when engaged. The slip elements 20 on the upper slip assembly 14 are oriented such that the slip elements 20 bite into the inside surface of the well casing 22 to anchor the packer 1 against being pulled upwardly within the well. Similarly, the lower slip assembly 16 is oriented such that the slip elements 20 anchor the packer 1 against being pushed downwardly within the well.
Referring to FIG. 2(b), the upper slip assembly 14 is frangibly secured by means of shear screws 26 to the mandrel 12. A take up spring 28 is likewise frangibly secured to the mandrel 12 by the shear screws 26. Slip springs 30 are provided to urge the slip elements 20 of the upper slip assembly 14 into a retracted position in which they are held away from engagement with the casing 22. The take up spring 28 generally urges the upper slip assembly 14 downward but the slip assembly 14 is initially prevented from moving on the mandrel 12 by the shear screws 26.
The lower slip assembly 16 also includes slip elements 20, and those slip elements 20 are urged into retracted position away from engagement with the well casing 22 by means of slip springs 32. Connected to the lower slip assembly 16 is a jay housing 34 within which is formed a set of jay slots 36 each having a lower trap 37 and an upper trap 39. The lower slip assembly 16 and jay housing 34 are frangibly secured to the mandrel by means of shear screws 38.
The sealing unit 18 is located on the mandrel 12 between the upper and lower slip assemblies 14, 16. The sealing unit 18 includes elastomeric seals 40 which are adapted to be pressed against the inside surface of the casing 22 to seal the annular area between the packer 1 and the casing 22 when the packer 1 is actuated. The sealing unit 18 is connected to an upper cone 42 and a lower cone 44 which are free to move relative to the sealing unit 18. The cones 42, 44 are configured to engage the slip elements 20 to force the teeth 24 outwardly to engage the well casing 22 upon actuation of the packer 1.
A set of jay pins 46 are connected to the mandrel 12 by way of connecting means 48. The jay pins 46 and hence the mandrel 12 are free to ride within the jay slots 36 formed in the jay housing 34.
At the upper end of the packer, coupling pins 50 extend radially outward and are adapted to nest within a trap 52 of a connecting recess 54 in an on/off tool 4 attached to a tubing string 56 (see FIG. 4(a)).
The mandrel 12 of the packer 1 includes a flow control device receiving annular groove 58 at the top portion of the packer mandrel 12. A flow control device such as a blanking plug 60 is seated in the plug receiving annular groove 58. The blanking plug 60 includes a prong 62 which extends upwardly above the top of the mandrel 12 when the blanking plug 60 is seated in the flow control device annular groove 58.
The blanking plug 60 is seated in the flow control device annular groove 58 during running of the packer 1 into the well and setting of the packer 1 by the wireline setting device 3.
The illustrated wireline setting device 3 is a device of the type well known in the art which is operated by means of an explosive charge (not shown). However, any known wireline setting device may be utilized within the ambit of the invention so long as it includes means for application of force in two different directions.
In the illustrated wireline setting assembly, the wireline setting device 3 includes a housing 64 and a plunger 66. An outer sleeve 68 of the adaptor 2 is connected to the housing 64 of the wireline setting device 3 and has a lower end resting on cap 70 of the upper slip assembly 14. A rod 72 of the adaptor 2 is connected to the plunger 64 of the wireline setting device 3 by means of rod adaptor 74. The rod 72 is in turn frangibly secured to the packer mandrel 12 by means of a shear collar 76 and a collet 78 including collet fingers 79. Specifically, the rod 72 includes a rod cone 80 located at the lower end of the rod 72 which forces the end of collet fingers 79 into engagement with recess 82 inside the top of the packer mandrel 12. The recess 82 is located above flow control device annular groove 58.
The shear collar 76 and rod 72 are telescoped through the collet 78 with the shear collar 76 initially firmly secured to the rod 72. As may be noted from FIG. 2(a), the rod cone 80 initially extends downwardly over the prong 62 and upper portion of the blanking plug 60.
In transport configuration of the packer (see FIGS. 2(a)-2(d)), the mandrel 12 is disposed in a lower position relative to the jay housing 34, with the jay pins 46 captured within the lower trap 37 of the jay slots 36 (see FIG. 2(d)). The upper slip assembly 14 and lower slip assembly 16 are held just touching the upper cone 42 and lower cone 44 respectively by the shear screws 26, 38. In this position, the packer 1 attached to the adaptor 2 which is in turn attached to the wireline setting device 3 are run down the well to a selected position.
Once located at the selected position, the wireline setting device 3 is actuated from surface by suitable means such as an electric charge sent down the wireline (not shown) causing a simultaneous application of force by the housing 28 through the sleeve 68 of the adaptor 2 to the cap 70 of the upper slip assembly 14 in a downward direction, and from the plunger 66 through the rod 32, shear collar 35 and collet fingers 79 to the mandrel 12 in an upward direction.
The upward force on the mandrel 12 pulls it upwardly causing the jay pin 46 connected to the mandrel 12 to pull upwardly on the jay housing 34 and lower slip assembly 16, breaking the shear screws 26. The slip elements 20 of the lower slip assembly 16 are then pushed onto the lower cone 44 forcing them from the retracted positions into their anchoring position wherein the teeth 24 bite into the well casing 22 and anchor the packer 1 from moving downwardly within the well. Similarly, the downward motion of the housing 64 shears the shear screws 26 and pushes the upper slip assembly 14 onto the upper cone 42 forcing the slip elements 20 of the upper slip assembly 14 into the casing 22. The take-up spring 28, being in a generally compressed condition, also urges the slip elements 20 of the upper slip assembly 14 onto the cone 42 ensuring that they engage the well casing 22 to anchor the packer 1 from moving upwardly within the well (see FIG. 3(b)). At the same time the sealing unit 18 is deformed such that the elastomeric elements 40 seal against the inside surface of the well casing 22 (see FIG. 3(c)).
Once the packer 1 is set in the well casing 22 with the sealing unit 18 deformed, continued setting force from the wireline setting device 3 shears the shear collar 76. As the wireline setting device 3 continues to stroke, the collet fingers 79 remain engaged in the recess 82 of the packer mandrel 12 while the rod 72 moves upward. Accordingly, the rod cone 80 is pulled from engagement with the collet fingers 79 and allows the collet fingers 79 to collapse and disengage from the mandrel 12. As seen in FIG. 3(a), the lower portion of the broken shear collar 76 and the collet 78 rest on the upper portion of the rod cone 80 so that they are retrieved along with the wireline setting device 3. Further, the wireline setting device 3 and adaptor 2 are completely released and removable from the packer 1 and may be retrieved from the well on the wireline (not shown) leaving the packer 1 behind with the blanking plug 60 seated in the flow control device annular groove 58 in the mandrel 12. This exposes the upper end of the packer and its coupling pins 50 for connection to the on/off tool 4 which is connected to the tubing string 56 (see FIG. 4(a)).
When it is desired to attach the packer 1 to the tubing string 56, the tubing string 56 with the on/off tool 4 connected to the end thereof is lowered onto the packer and the tubing string 56 is manipulated to latch the on/off tool to the coupling pins 50 of the packer.
After the tubing string 56 is attached to the packer 1 flow through the packer mandrel 12 and tubing string 56 may be reestablished by removal of the blanking plug 60 through standard wireline techniques.
When it is desired to retrieve the packer 1 from the well the slip assemblies 14, 16 must be released from their set position. In order to release the slip assemblies 14, 16 from their set position, the tubing string 56 and mandrel 12 are lowered slightly while applying torque to the tubing string 56. This shifts the jay pin 46 out of the lower trap 37 so that an upward pull on the tubing string 56 while maintaining the torque thereon causes the mandrel 12 to travel upwardly with the jay pin 46 riding within the jay slot 36 into the upper trap 39 (FIG. 4(d)). As the mandrel 12 is lifted, a shoulder 84 near the top of the mandrel lifts the upper slip assembly 14 off the upper cone 42 and slip springs 30 retract the slip elements 20 and release the force applied to the sealing unit 18 which returns to its undeformed condition (FIG. 4(b)). As the mandrel 12 continues moving upwards, a shoulder 86 on the lower portion of the mandrel 12 engages the bottom of the sealing unit 18, moving it upward which in turn lifts the lower cone 44 out from engagement with the lower slip elements 20 of the lower slip assembly 16 and slip springs 32 retract the lower slip elements 20 disengaging them from the well casing 22 (FIG. 4(c)). The tubing string 56 and the packer 1 may then be retrieved from the wall.
Those skilled in the art will recognize that the aforesaid description is by way of example only. Modifications may be made within the scope of the invention as set out in the appended claims. | A retrievable production packer is conditioned for initial wireline installation in a well utilizing an adapter comprising an outer sleeve and an inner rod connected to a mandrel carrying the slip assembly of the packer. The packer is frangibly supported in an initial transport condition for being set by means of a wireline setting device. A flow control device, such as a blanking plug, may be seated in the packer mandrel at the very top of the packer while being lowered into position and set with a wireline setting device. Thereafter, the tubing string may be connected to the packer downhole to release the packer and retrieve it from the well. | 4 |
This application is the national phase under 35 U.S.C. § 371 of PCT International Application No. PCT/FI02/00233 which has an International filing date of Mar. 20, 2002, which designated the United States of America.
The present invention relates to a method for the separation of two phases from each other.
According to such a method, a stream composed of at least two phases is directed to a separation apparatus, which includes cyclones arranged in parallel and in succession in the flow direction, the cyclones having an elongate separation chamber, wherein the phases are separated from each other.
The invention also relates to a cyclone system which includes cyclones arranged in parallel and in succession characterized in that the cyclones are multi-inlet cyclones the total number of which is at least 10 and in which the separated phases are removed in the same direction. The invention further relates to a separation apparatus which includes a separation container having a feed port for the stream to be treated, an outlet port for the treated stream, and, in the bottom of the separation container, an outlet port for the separated phase; and a cyclone system arranged inside the separation container, the system having cyclones arranged in parallel in the direction of the flow, each system having an elongate separation chamber in which the phases of the stream directed into the cyclone can be separated from each other.
Furthermore, the invention relates to a multi-inlet cyclone which includes an elongate, at least substantially cylindrical separation chamber having an inlet end for the stream being treated and an outlet end for the solid or liquid material separated from the stream, a cover covering the inlet end of the separation chamber and a vane system arranged at the inlet end of the separation chamber for guiding the stream being treated against the wall of the separation chamber, characterized in that the vane system is formed as a piece integral with the cover covering the inlet end of the separation chamber, the vanes being made up of strips formed on the outer edge of the cover by cutting and bending into the desired position.
BACKGROUND OF THE INVENTION
In strongly exothermal or endothermal reactions, such as catalytic cracking, dehydrogenation and the combustion of solid fuels, there are used fluid-bed reactors (fluid catalytic reactors or fluid-bed boilers). By “fluid-bed apparatus” is meant below an apparatus used in processes wherein a finely-divided catalyst powder or solid is distributed in, for example, a gas stream moving slowly upwards, wherein it causes the desired reactions and/or transports thermal energy.
One of the most commonly used fluid-bed apparatuses is the FCC apparatus, i.e. fluid catalytic cracking apparatus, the main components of which are a riser operating in the range of a rapid fluidizing flow, a large-volume reactor operating in a dilute suspension phase, and a regenerator operating in the fluid-bed range.
In an FCC unit, the solid particles and product gas of the solids suspension obtained from the riser and the large-volume reactor are separated from each other in cyclones the operation of which is based on the exploitation of centrifugal force. Usually cyclones are installed in series in the direction of the gas flow in order to improve the total separation degree, since the degree of separation of normal individual cyclones is poor with particles of less than 15 μm.
The cyclones may be by structure helical or spiral, in which case the solids suspension is introduced as a tangential stream into the cylindrical part of the cyclone and the catalyst separates from the gas by passing to the vicinity of the wall, the stream typically circulating 7–9 rotations in the cylindrical part of the cyclone and in the conical part constituting its continuation. There are also known axial cyclones wherein a gas traveling in a pipe is brought by means of a vane system into a rotary motion, whereupon the solids are driven under centrifugal force to the wall of the pipe, thus separating from the gas stream.
Axial-flow cyclones are described in GB patent publications 1 592 051 and 1 526 509. The axial-flow cyclone according to these publications has a tubular cyclone chamber at the upstream end of which there is an inlet for the stream to be treated and at the other end an outlet for purified gas. It is proposed that the said cyclones be used in combustion, diesel and jet engines, turbines or similar apparatuses requiring pure feed air.
Stricter air protection requirements and the lowering of pressure, carried out by means of turbines, of the FCC regeneration gas, in order to make the use of energy more efficient, set even stricter limitations than previously on the dust content in FCC. It is possible to improve the separation efficiency by reducing the diameter of the cyclone, but the number of cyclones has to be increased correspondingly. It can be stated in general that the separation of small particles requires a small-diameter cyclone. However, the manufacture of small cyclones increases the cost of investment of the apparatus, unless there is used a structure allowing mass production by using, for example, thin-sheet technology. Furthermore, the manufacture of small parts, for example the welding of small vanes, is a problem in conventional methods. Commercial multi-cyclone options (e.g. Shell's TSS) for their part require a large-volume pressure vessel. The structure of multi-cyclones becomes a problem when the direction in which the gas is directed is the same as that from which it comes.
The problems involved with conventional FCC units include, in addition to deficient separation capacity, also the erosion of the catalyst/solid and the structures. The problems are most commonly associated with the gas and solids/catalyst separation cyclones that constitute an essential part of the apparatus. To prevent wear, conventional cyclone structures have to be lined with a ceramic paste. The problems caused by erosion become emphasized when the diameter of the cyclone is reduced.
The object of the present invention is to eliminate the disadvantages associated with the state of the art and to provide a novel option for the separation of solids from gases.
The invention is based on the idea that a separation apparatus is used which comprises a plurality of normal-structured but relatively small-sized multi-inlet cyclones arranged in parallel, the cyclones together constituting a cyclone system, i.e. a configuration made up of a plurality of cyclones.
The separating of solids from a gas stream with the help of a cassette containing a plurality of cyclone units is previously known from CA patent 853 025, DE patents 1 004 463 and 1 058 343 and U.S. Pat. Nos. 2,806,551 and 3,448,563. DE patent publication 1 058 343 and CA patent publication 853 025 disclose a cassette made up of axial-cyclone units, wherein the stream is directed to the cyclone in the axial direction. Owing to the feed direction the stream arrives in the cyclone chamber as a relatively wide jet, in which case the particles have on average a moderately long distance to travel from the feed inlet to the wall. Structurally known apparatuses are partly quite complicated, and their degree of separation is not sufficient to take into account the stricter requirements mentioned above.
GB patent publication 545 624 describes a cyclone unit in which a stream containing particles (dust) enters the cylindrical pipes of the cyclone system from the side via special inlets, and the stream is brought into a rotary motion. The separated dust flows down along the pipe wall into a collection silo, whereas the gas stream turns, in the manner of a conventional cyclone separator, upwards to an outlet pipe, to be directed away from it. The operation of the cyclone is based on the reverse flow principle, which leads to a relatively complicated structure.
SUMMARY OF THE INVENTION
According to the present invention, the multi-cyclone is implemented using multi-inlet cyclones by fitting at least 10 multi-inlet cyclones in parallel and in succession in the flow direction of the material to be treated. With cyclones such as this, high separation efficiency is achieved, combined with a simple and economical structure. Furthermore, the high separation efficiency makes a compact structure possible.
The cyclone system can be formed by installing the separation chambers of the individual cyclones between two sheets fitted at a distance from each other and defining, between them, a partly closed space which serves as a collection and outlet conduit for the phase, e.g. solids, separated in the separation container. The cyclone system can in this case be installed and replaced easily like a cassette.
A multi-cyclone made up of multi-inlet cyclones can be fitted in a separation container which has a feed port for the stream to be treated, an outlet port for the treated stream and an outlet port for the separated phase, whereby there is obtained a separation apparatus which allows a through-flow of gas and is suited for the separation of two phases from each other. Owing to the advantageous structure of the multi-inlet cyclone system, the ratio of the cross-sectional area of the separation container to the cross-sectional area of the inlet conduit may be small, typically approx. 1–20.
According to the invention, the multi-inlet cyclones of the multi-cyclone can be implemented using conventional technology. A cyclone comprises an elongate, at least substantially cylindrical separation chamber having an inlet end for the stream to be treated and an outlet end for the solids or liquid material separated from the stream, a cover for the inlet end of the separation chamber, and a vane system arranged at the inlet end of the separation chamber to guide the stream being treated against the wall of the separation chamber. According to the invention, the vane system is made so as to form an integral part of the cover covering the inlet end of the separation chamber, and the vanes consist of strips formed on the outer edge of the sheet-like cover by cutting and by bending into the desired position.
More precisely, the method according to the invention is mainly characterized in what is stated in the characterizing part of Claim 1 .
The invention provides considerable advantages. Thus, when a large number of multi-inlet cyclones are placed in parallel, a purification element resembling a filter is obtained. The essential idea is that gas flows through the apparatus and that the solids are separated into the intermediate space. Compared with a filter, continuous “regeneration” occurs in the element, and thus the pressure loss does not increase during operation, since the solids do not reduce the cross-sectional area of the flow conduit inside the element. A system such as this enables the separation efficiency of the cyclone unit to be increased by the reduction of the cyclone size, but without increasing the cost of manufacturing the apparatus. Furthermore, the cyclone can be dimensioned so as to be optimal with respect to the suspension properties.
Preferably the flow is implemented as a uniflow-type flow, which means that the separated phases are removed in the same direction. In this respect the option according to the invention differs from the prior-known options in which the purified gas stream is removed against the feed stream.
Shear stresses, which cause erosion, are in the multi-inlet multi-cyclone according to the invention smaller than in conventional multi-cyclones, for example the above-mentioned multi-cyclones based on axial cyclones. Implemented with multi-inlet cyclones and in the manner described in the invention, the multi-cyclone is more efficient and more economical than the multi-cyclone based on axial cyclones. In an axial cyclone, the solids-containing flow cannot be accelerated in the flow duct, which would be desirable in order to increase separation efficiency. A multi-inlet cyclone, instead, has typically straight vanes by means of which the stream is divided into partial streams, and the flow velocity of each of these streams can be accelerated effectively. Straight vanes are less prone to wear than curved vanes, since they are not oriented substantially to deflect the flow direction but only to accelerate the gas flow velocity.
In an FCC apparatus the multi-inlet multi-cyclone serves especially effectively as the separator of stage 2 or 3, since the stream is brought close to the wall of the separation chamber by means of the said vanes. Indeed, with the apparatus according to the invention, small particles, especially the above-mentioned particles less than 15 μm in size, can be separated from the exit gases more effectively than at present, and thus, with a very economical option, an FCC apparatus can be brought to meet the increasingly strict requirements concerning FCC dust content.
By the use of the multi-inlet multi-cyclone according to the invention and present-day FCC catalysts, it is possible to reach a dust content below 50 mg/Nm 3 in exit gas if the apparatus serves as a secondary or tertiary separator.
The present option can also be used at very high temperatures, for example in connection with hot combustion gases or reaction products. Thus the invention is also suitable for use in energy production, where the problem is that often there arrive at the electro-filters considerable amounts of unburnt components that load and soil the electro-filter. By the use of the cyclone system according to the invention, it is possible to reduce the use of electro-filters, which are considerably more expensive in terms of investment, space requirement and operating costs. A multi-inlet cyclone system can be fitted in particular at a point upstream of an electro-filter to remove unburnt components and fly ash.
By the use of more efficient cyclone separation, unburnt components can be recycled to the combustion process, and thus the efficiency can at the same time be raised. In certain cases the electro-filter can be replaced entirely.
The multi-inlet cyclone according to the invention, wherein the separation chamber cover with its guide vanes is formed by cutting and bending from a suitable sheet-like blank, is in terms of manufacturing technology a very economical option, enabling multi-inlet cyclones to be mass produced. The technique can be applied to different materials, both plastics and metals. Thus a cyclone cap (see below in greater detail) functioning at low temperatures can be made, for example, from plastic by injection molding, and those functioning at higher temperatures by casting or by work methods associated with thin-sheet technology.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described below in greater detail, with reference to the accompanying drawings.
FIG. 1 a depicts the principle of the structure of an individual cyclone of the cyclone system according to the invention, as a cross-sectional side-elevation, and FIG. 1 b depicts a cross-section of the cyclone;
FIG. 2 a depicts, seen from above, a sheet blank used for forming the cover 2 of the cyclone according to FIG. 1 a , and FIG. 2 b depicts, seen from below, the cyclone cover according to FIG. 1 a , bent into shape;
FIG. 3 a depicts a side elevation of the structure of a container space comprising a multi-cyclone system according to the invention, and FIG. 3 b depicts a corresponding plan view of the structure, partly opened;
FIG. 4 a depicts a side elevation of a filter package according to the invention, and FIG. 4 b shows a plan view of the same option; and
FIG. 5 depicts a side elevation of a cyclone system having a cylindrical shape;
FIG. 6 depicts a side elevation of a cylindrical cyclone system serving as the second-stage separator in a separation apparatus;
FIG. 7 depicts a detail of FIGS. 5 and 6 of an individual cyclone element.
DETAILED DESCRIPTION OF THE INVENTION
In the method according to the invention for the separation of two phases from each other, a stream consisting of two phases is directed to a separation apparatus wherein the separation is carried out with a “cyclone system” made up of multi-inlet cyclones (i.e. an apparatus comprising a plurality of cyclones arranged in parallel). The stream being treated may consist, for example, of a gas stream containing a solid material, a gas stream containing suspended liquid drops, or a liquid flow containing solids. The term “cyclone” is used in the present invention to denote separators intended for the treatment of any of these streams, in which separators the separation is at least in part based on centrifugal force produced by the stream when it is directed to the wall of the separation chamber of the cyclone.
The essential difference as compared with the axial cyclones described in the preamble is that in the multi-cyclone according to the invention the stream being treated is directed to each multi-inlet cyclone in a substantially radial direction, i.e. the stream is introduced into the separation chamber from the side of the chamber, in a direction transverse to the longitudinal axis of the separation chamber. In cases in which the stream being treated is directed to the cyclone system in a linear flow motion, all of the individual cyclones of the cyclone system are preferably oriented in the same direction. They can, however, be arranged even in some other manner, for example so that the longitudinal axes of the separation chambers of any two adjacent cyclones together form an equal angle, which is smaller or greater than 90 degrees.
The multi-inlet cyclone is previously known, and it has been described in, for example, U.S. patent publication 3,969,096. Cascades made up of a plurality of multi-inlet cyclones are also known. In this respect we refer to the option disclosed in our PCT application publication WO 99/25469. The total separation degree can be improved significantly by the arrangement of a plurality of multi-inlet cyclones successively. In addition, considerable savings of space are achieved when the separator cascade is built up from multi-inlet cyclones, since the cyclones can be placed one inside the other. Our patent application FI 2000 0262 describes the fitting of multi-inlet cyclones in parallel, but therein the gases are removed in a direction different from that of the catalyst, in which case the construction becomes complicated and expensive, especially if the diameter of the cyclones is reduced.
The cyclone unit according to the present invention comprises at least ten multi-inlet cyclones arranged in parallel and in succession, each cyclone having a “cyclone cap” made up of a guide vane system which brings the solids-containing stream being treated into a substantially tangential flow in order to separate the solids from the gas, a rotationally symmetrical separation chamber attached to the “upper sheet,” and a purified-gas outlet pipe that is coaxially disposed inside the separation chamber, the separated catalyst leaving together with a small gas stream and passing from between these pipes into the space between the upper and lower sheets, the inlet conduits of the multi-inlet cyclones communicating with one space, the ports for separated solids with another space, and the pipes for purified gas with a third, common space.
By arrangement “in parallel” is meant in the present invention that all cyclones have a common feed conduit and a common outlet conduit. The central part of the device is its separation chamber, the cross-section of its inner surface being substantially circular, i.e. the separation chamber is rotationally symmetrical with respect to its central axis. In a multi-inlet cyclone the central axes of the separation chambers of all parts are concentric. In the multi-inlet multi-cyclone the central axes of the cyclones may be oriented in the same direction or, if such a structure provides an advantage, radially, in which case the space for separated solids is the space formed between two cylinders.
The total number of multi-inlet cyclones is preferably 20–1000. They can be arranged in parallel and in succession in such a manner that, seen from above, they form a polygonal pattern. Usually they are arranged in the manner of a quadrangle, but generally they may be arranged in the pattern of a triangle, hexagon or octagon.
According to an especially preferred embodiment there is formed from the multi-inlet cyclones a cyclone cassette, which is easy to install and replace. Such a cassette structure can be fitted, for example, in a separation container, into which the stream to be treated is introduced via an inlet and from which the purified stream is removed via an outlet. The separation container may have several cyclone cassettes; preferably their number is 1–10. The ratio of the cross-sectional area of the separation container inlet port to the cross-sectional area of the separation container is relatively small, usually 1–20, which means an effective saving of space.
When solids are being separated from a gas, gravity often suffices to transfer the solids from the cyclone separation chamber to the solids collection vessel and removal. When a liquid phase containing solids is being treated, it is, instead, advantageous to rinse off the solids separated from the liquid by directing to the separation chamber a flowing medium, usually a pure liquid such as water, in order to form a suspension which contains solids. This suspension is thereafter removed separately from the solids-free liquid phase that has been treated in the separation chamber. The solids are thereafter separated in a separate cyclone from the said suspension obtained from the separation chamber. Preferably the separation chamber of the said cyclone is in a substantially vertical position.
Preferably the separation surface is increased by fitting the multi-inlet cyclone system in a position oblique to the stream to be treated. Thus the stream is introduced into a multi-inlet cyclone system wherein the longitudinal axes of the separation chambers of the cyclones are arranged at such an angle relative to the horizontal plane that they form an angle of 30–90°, preferably approx. 45–90°, to the horizontal plane.
The individual multi-inlet cyclones of the cyclone system according to the invention comprise each a cylindrical separation chamber on the inlet side of which there is arranged a separation vane system for guiding the stream to be treated to the wall of the separation chamber. Furthermore, the separation chamber is covered with a cover sheet to direct the stream introduced into the cyclone into the separation chamber in a radial direction. According to a preferred embodiment, the separation vane system is connected to the said cover/cover sheet. By means of the guide vane system the gas being treated can be brought into a gas flow along the inner surface of the separation chamber in order to separate the solids from the gas under the effect of centrifugal force. There are at least 2, preferably 3–20, guide vanes. The guide vanes in the cyclone are fitted in a circle on the circumference of the cyclone chamber, in part or entirely as a flow conduit guide vane system so that this system forms a plurality of parallel gas inflow conduits. In the separation chamber there is further arranged a central pipe for the removal of the gases and a conduit for the recovery of the solids separated from the gas.
In a preferred embodiment of the invention, the multi-inlet cyclone's separation vane system, which is formed as a piece integral with the cover covering the inlet end of the separation chamber, comprises strips formed in the outer edge of the cover by cutting and bending into the desired position. The cover or cap need not be fastened gas-tightly to the cyclone pipe; it may be a separate part fitted on top of the cyclone pipe, in which case its attaching, repairing and possible cleaning can be done easily. Such a cover is made, for example, from one polygonal blank sheet the number of angles in which corresponds to the number of vanes in the vane system. The cover can be made from the said sheet by first marking a bending line which runs from the center point of the sheet to the center point of each side, whereafter a cut is made in the sheet from the center point of the adjacent side of each side perpendicularly towards this first bending line as far as the bending line. The cut strip is bend from the continuation of the cutting line to a 90-degree angle relative to the plane of the sheet, and then along the first bending line to such an angle that, when the cover is installed in place, the vane points at least approximately in a direction tangent to the separation chamber wall.
In the manner disclosed, the vane system can be formed from a sheet by cutting and bending, completely without any weld or other corresponding seam.
Owing to its good separation capacity, the separation chamber of a multi-inlet cyclone may be shorter than the separation chamber of an axial cyclone. Thus, in the option according to the invention, the ratio of the length to the diameter of the separation chamber of an individual multi-inlet cyclone is approx. 1:1 . . . 3:1.
The outlet ends of the separation chambers of the multi-inlet cyclones open into a common collection space for the separated solid or liquid material. Each separation chamber has an outlet pipe for the fluid substance free of the separated solids or liquid, this pipe being arranged concentrically inside the separation chamber.
From the multi-inlet cyclones described it is possible to manufacture the cyclone cassette described above by fitting the cyclones between two sheets, an upper sheet and a lower sheet. The upper sheet and the lower sheet are interconnected at their sides, but so that between them is left at least one opening from which the material collected in the intermediate space can be removed. The cassette option thus in general comprises a first sheet, a second sheet arranged at a distance from the first sheet, and at least 10 multi-inlet cyclones which are perpendicular to the sheets and of which each extends through the first sheet and the second sheet in such a manner that the inlet end of the cyclone separation chamber opens into an opening in the first sheet, the outlet end of the outlet pipe opens into an opening in the second sheet, and the outlet end of the separation chamber opens into the space between the first sheet and the second sheet, this space constituting the collection space for the separated solid or liquid material. The cassette is usually substantially planar, but it may also be cylindrical or curved.
According to a preferred embodiment the cassette can be manufactured by, for example, thin-sheet technology and working methods associated with it. The cassette is made from sheet metal, inlet and outlet pipes (inlet and outlet ports) are fastened gas-tightly to it, and on top of the inlet pipe there is fitted a cover made up of a cyclone vane system.
We have noted that the separation capacity of a cyclone is better when the gas or corresponding flowing medium is removed in the same direction as the solids, since the axial flow in the outlet conduit will not carry with it the already separated solids. As was pointed out above, a uniflow type flow provides a simple and advantageous construction.
In an operation according to the invention, it is not necessary to make the common catalyst collecting space of the cyclones conical as has been done, for example, in Shell's. TSS separator: when the cyclones are installed in a common cassette, the solids can be removed by installing the entire cassette obliquely or vertically. When the gas is removed through the apparatus, this option is possible. The cassette structure facilitates cleaning and maintenance work; the entire cassette can be replaced and cleaned on premises suitable for the purpose. The structure also facilitates its application to existing conduits, since the element can be shaped freely (in a round or angular, vertical or horizontal conduit). The solids collect in the common, closed space inside the cassette and can be removed from the lower part of the cassette. Solids made up of small particles are best removed in the form of a thick suspension, i.e. a small amount, 1 . . . 3%, of the gas travels with the solids.
In the method according to the invention, the multi-inlet multi-cyclones can be formed as part of a multi-stage separation apparatus. Thus, according to the first embodiment of the invention, the separation apparatus comprises a 1-stage or 2-stage primary separator and a secondary separator that is the multi-inlet multi-cyclone described above. In this context we refer to the option disclosed in application publication WO 99/25469.
The apparatus and process described above can be applied to the separation of a catalyst from the product gases of fluid-catalytic cracking (FCC). The multi-inlet multi-cyclone can be used especially advantageously in the regenerator of an FCC unit for separating the regenerated catalyst from the coke combustion gases.
Other fluid catalytic applications include: catalytic reforming; oxidizing dimerization of phthalic acid anhydride, maleic acid anhydride, methane; Fischer-Tropsch synthesis; chlorination and bromination of methane, ethane, etc.; and the conversion of methanol to olefins and gasoline.
In the production of liquid fuel from chips, there is formed, in addition to the products, a carbonization residue (coke), from which the portion that cannot be separated by means of the reactor cyclones travels, together with the gaseous-state product, to product condensers and is left in the forming liquid fraction. Maximally effective separation of the carbonization residue is of primary importance for the stability of liquid fuel made from chips. For this purpose, the option according to the invention is, in terms of investment, considerably more economical and more reliable in operation than the previously used hot filters. That portion of the carbonization residue separated by the reactor cyclones travels together with the used fluidization material into the combustion chamber (regenerator), where it is burned, the heat-transferring solids serving as the fluidization material. In the process there is produced ash, which has to be removed from the hot combustion gas before the combustion gas is directed to the biomass dryer. It is also advantageous to remove the ash from the hot combustion gas by using a cyclone system according to the invention. The fuels usable in the process include various biologic materials and waste products. The biomass feedstock is preferably selected from among forest industry wastes and forest thinning residues; agricultural waste such as straw, residues from olive thinning or harvesting; energy plants such as willow, energy hay, Miscanthou and peat. The wastes are most preferably organic, solid or liquid, and they are selected from among refuse-derived fuel (RDF), sawmill waste, plywood, furniture and other waste of the mechanical forest industry; waste plastics; and liquid waste (including industrial and municipal waste).
The option according to the invention is especially advantageous for application in cases in which the purification has to be carried out under elevated pressure, such as: pressurized fluid bed combustion (PFBC) and integrated gasification combined cycle (IGCC) power plant. In these, the combustion gas has to be purified especially effectively in order to minimize the erosion-corrosion of the gas turbine blades. By the application of the cyclone system according to the invention, the use of very expensive hot filtration implemented with ceramic sinters can be avoided.
In atmospheric partial oxidation (gasification) of a solid fuel wherein the product gas is burned, the cyclone system according to the invention can be used for the removal of ash from either the product gas or the combustion gas.
For the removal of dust from a gas stream, the cyclone system according to the invention can be used, for example, in the purification of the intake air of gas turbines, in the extractive, metal, carpentry, food, pharmaceutical and chemical industries and in HEPAC applications (air-conditioning, vacuum cleaners). The option is also suitable for the removing of small liquid drops (mist) from a gas stream, and it can replace, for example, space-consuming demister systems in industry, which systems are based on causing drops to impinge against a structure made from sheets or wire.
Hydrocyclone options are used, for example, in connection with oil drilling and in the extractive industry, as well as various chemical processes in which solids are separated from liquids. Multi-cyclones made up of very small cyclones are already being used in these. The cyclone system according to the invention is, however, simpler and thus considerably more economical in terms of investment than are present-day options.
In the process for producing liquid fuel from chips, multi-inlet cyclones can be used on the product side for the removing of carbonization residue particles from the product gas and instead of a demister in the separation of uncondensed gases and liquid product. Furthermore, the space-consuming liquid separation drums in the flare line can be replaced with the multi-inlet cyclone option according to the invention.
The preferred embodiments according to the drawings are discussed below.
FIG. 1 a shows a side elevation of a cyclone element according to the invention, which is part of the multi-cyclone according to FIGS. 3 , 4 , 5 and 6 . FIG. 1 b shows a cross-section of the cyclone element.
According to a preferred embodiment, the vane system of a small-sized cyclone is made from one single thin sheet piece, for example, a metal sheet piece, by cutting and bending the edges of the piece into a certain polygonal shape without a weld or other similar joint. The obtained piece serves as the cover for an individual cyclone in the cyclone cassette.
FIG. 2 a shows one possible blank; by bending this blank at bending lines 12 and 13 , there is obtained the completely shaped vane system shown in FIG. 2 b . Alternatively the cyclone cap 2 can be made, for example, by injection molding from plastic or by casting from metal.
The gas and the solid particles or liquid drops carried therein it travel to all of the cyclones in the multi-cyclone through a common conduit 1 , into vane slots between the vanes 3 of the cyclone cap 2 . The cyclone vanes 3 guide the gas stream into a rotary motion in the space 11 inside the cyclone chamber, whereupon the particles separate from the gas onto the chamber wall 4 and travel through the space 9 between the cyclone chamber wall 4 and the pure-gas outlet pipe 5 into the inner space 10 of the cassette, which is space common to the parallel cyclones in the same cassette. The separated solids and the purified gas are removed from the cyclone chamber in streams that flow in the same direction.
The purified gas travels via the outlet pipe 5 into the purified-gas space 8 , which is a space common to all of the cyclones of the cyclone system. The cyclone separation chamber is fastened to the first sheet 6 , and the cyclone cap 2 is centered by means of the vanes 3 on the outer surface of the inlet end of the cyclone separation chamber 4 . The outlet end of the outlet pipe 5 is fastened to the other sheet 7 . The space between the sheets 6 and 7 constitutes the collection space for the solid or liquid material. When the sheets 6 and 7 are interconnected, there is obtained a vessel, cyclone cassette, which can be placed in the separation container connected to the gas conduit.
FIGS. 3 and 4 show possible options for locating a cyclone cassette as part of a flow conduit.
FIG. 3 shows the structure of a separation apparatus according to the invention. In the separation apparatus there is fitted inside the separation container 25 a cyclone cassette 22 , which is made up of in particular two sheets 24 , 28 , oriented in the same direction and fastened to each other, between which and fastened to which there are cyclone elements 26 , and of fixedly fastened edge sheets between the sheets in all directions. The cassette 22 is installed obliquely across the entire gas conduit. On the upper, upstream side of the cassette, there is a perforated sheet 24 in each perforation of which, inside the cassette, there is fastened air-tightly a separation pipe that is shorter than the distance between the sheets and, outside the cassette, a cover sheet larger than the perforation, on the lower surface of which, between the cover and the upper sheet, there are fastened the guide vanes of the cyclone. The bottom sheet 28 , on the lower, gas-outlet side, has perforations in alignment with those in the upper sheet, the diameter of these latter perforations being smaller than those in the upper sheet and there being fastened to them air-tightly, inside the cassette, outlet pipes having a smaller length than the separation pipes.
The gas stream to be purified enters the separation container 25 , passing from the separation port 21 into the space 23 , and is divided among the cyclone elements 26 . The functions of a cyclone element are described in connection with FIG. 1 . The purified gas enters the space 29 for purified gas through the cassette and leaves via port 33 . The stream of solids or liquid leaves via port 31 . A structure such as this is especially advantageous when there is separated from a gas stream a liquid, which flows easily inside the space 27 to the outlet port 31 .
In FIGS. 4 a (side elevation) and 4 b (plan view), the cyclone cassettes are installed in a vertical position and the cyclone elements are horizontal. The gas stream to be purified arrives via port 41 into space 43 of the separation container 45 and divides into the space 47 between the cyclone cassettes 46 and then further to cyclone elements 48 . To divide the stream in space 43 it is possible to use flow guides 42 . The purified gas comes via the cassette into space 49 and further to a common space 44 . The purified gas leaves the separation container via port 50 . The lower parts of the cyclone cassette are connected to outlet ports 40 , through which the separated solids are removed from the separator. This structure is especially advantageous when cassettes need to be handled owing to erosion or soiling. The cassettes can in this case be installed in slots 39 and can thus be removed via the upper or lower part of the apparatus for repair, replacement or maintenance.
FIGS. 5 and 6 depict a cyclone system according to the invention, having a cylindrical shape. The cyclone element picture DET.X is common to both figures.
In FIG. 5 the gas to be purified comes, via the feed port 51 for the stream to be treated, to the space 53 inside the separation container, from which space the gas divides to the cyclone elements disposed in parallel. Inside a cyclone element the gas travels via the vane slots of the cyclone cap 63 , where the vanes 62 direct the gas into a rotary motion inside the cyclone chamber 67 . The particles separate from the gas to the wall 65 of the cyclone chamber and travel through the space 69 between the cyclone chamber wall 65 and the outlet pipe 71 for pure gas to the solids separation space 59 . The separation space is the space delimited by the outer cylindrical wall 61 of the cyclone system and its inner cylindrical wall 57 . The purified gas travels via the outlet pipe 71 to the space 75 for purified gas, which is a space common to all of the cyclones of the multi-cyclone. The separated solids are directed out of the separator via port 73 . Often, for the purpose of solids transport and a smooth flow of the gas, it is preferable to direct together with the solids a small amount of gas, in which case the solids are considerably more concentrated in the carrier gas stream. In this case the suspension is directed via port 73 to a further outside separator, where the solids are separated from the carrier gas.
FIG. 6 shows how the cyclone system can be installed to serve as a second-stage separator. The gas to be purified comes into the separator through the feed port 52 for the stream to be treated; the separator is in this case a conventional 1-inlet cyclone. The gas enters tangentially the cyclone chamber 56 , where the particles separate to the cyclone wall 54 and continue their travel via the cyclone cone 58 to the cyclone leg 60 . The pre-purified gas travels in the space 51 to the space 53 inside the separation container 55 , from where the gas is divided in the manner shown in FIG. 5 to cyclone elements, which are disposed in parallel. Inside the cyclone elements the gas and particles travel as indicated in the description of FIG. 5 . The solids separation space 59 communicates with a common conical part 73 , from where the separated particles travel to the dipleg 74 and further to the dipleg 60 of the first-stage separator. | The invention relates to a method and apparatus for separating two phases from each other. According to the invention, a stream made up of at least two phases is directed to a separation apparatus, which comprises a separation container ( 25 ) and cyclones ( 26 ) arranged in the flow direction in parallel and in succession, the cyclones having each an elongate separation chamber wherein the phases are separated from each other. According to the invention, the cyclones used are multi-inlet cyclones ( 26 ), the total number of which is at least 10. The stream to be treated is directed to each multi-inlet cyclone ( 26 ) in a substantially radial direction. Through the placement of a large number of multi-inlet cyclones in parallel, a purification element resembling a filter is obtained. In comparison to a filter, continuous regeneration takes place in the element, in which case the pressure loss does not increase during operation, since solids do not reduce the cross-sectional area of the flow conduit inside the element. | 1 |
This is a Division of application Ser. No. 07/922,329, filed Jul. 30, 1992, now U.S. Pat. No. 5,422,015.
TECHNICAL FIELD
The present invention relates to treatment of pathogen containing solid waste such as sewage sludge to reduce the pathogens to a safe level and convert the sludge to a useful product. More particularly, this invention relates to combining sludge or other solid waste with heat generating treatment chemicals that pasteurize the waste and convert it to a soil amendment or fertilizer.
BACKGROUND OF THE INVENTION
Ever increasing population results in a continuously increasing amount of solid waste. It also places stress on water supplies since potable water is used to flush much of human solid waste to treatment plants and sometimes directly to bodies of water used for human consumption. Pollution control authorities such as the Environmental Protection Agency, require that sewage be treated in several stages before being released into lakes, rivers, or the ocean. In 1985, Public Operated Treatment Works (POTW) were required to upgrade water treatment facilities to include secondary treatment for plants with ocean discharge and tertiary treatment for other plants. The end result of these regulations is improved water quality and increased volumes of sewage sludge. Sewage is now disposed of in land fills, surface sites, incineration or application to land. Land fill and surface sites are rapidly filling. Incineration requires the use of expensive fuel and contributes to air pollution. A natural use for sewage sludge and other solid, animal waste products such as residuals of waste water treatment, septages and animal manure would appear to be application to land in agricultural production due to the organic and mineral components of the waste.
However, feces containing solid waste tends to have a high pathogen content. If the sludge is not treated to reduce the pathogen content, land receiving application of the waste can not be used for animal grazing or food crop production for 5 years after the last application of solid waste. Furthermore, solid waste may contain heavy metal ions which may be hazardous to animals or could accumulate in the soil and render it unsuitable for agriculture.
Regulations have been promulgated by the Environmental Protection Agency establishing criteria and conditions for the reuse of these materials. Use limitation criteria are based on deleterious constituents such as heavy metal and pathogenic organisms. Concurrent with reuse guideline development has been the reduction in the number of disposal sites willing and capable of accepting sludges, septages, manures and residuals. Similarly, manures are being increasingly scrutinized for the impact from storage facilities on ground and surface waters. The net effect of these regulations has been dramatic increase in the cost for treatment and disposal of sludges, manures and septages.
Several Processes to Significantly Reduce Pathogens (PSRP) have been developed that reduce both pathogen levels and the attractiveness of sludges to disease vectors. The processes effectively reduce pathogenic viruses and bacteria by about 90%. The PSRP process that have been recognized are aerobic digestion, anaerobic digestion, lime stabilization, air drying and composting.
Aerobic digestion involves biochemical oxidation of sludge in an open or closed aerobic tank and can be practiced in a batch or continuous mode. The digestion requires 40 to 60 days residence time at temperatures from 15 to 20 degrees Celsius. Anaerobic digestion is conducted in the absence of air. Even with added heat the process still requires 15 days to digest the waste.
In air drying the wet sludge is generally applied to sand and/or gravel beds to a depth of up to about 9 inches. To be considered a PSRP the sludge must be air dried for at least 3 months. Lime stabilization involves adding lime to sludge in a sufficient quantity to produce a ph of 12 after 2 hours. The treatment period is short. However, lime is expensive and the pathogens can regrow if the pH drops below 11. Composting to meet PSRP conditions requires treatment for at least 5 days at 40 degrees Celsius with 4 hours at a temperature of at least 55 degrees Celsius.
The PSRP processes can be combined with other processes to further reduce the pathogen to a level below the detection limit. Some of the same processes discussed as PSRP processes can qualify as a PFRP (Process to Further Reduce Pathogens) if operated at high temperature.
Treatment processes demonstrated to be effective in reducing pathogen content of waste sludges, septage and waste water residuals have been identified and defined by the EPA. Regulations (40 CFR parts 257 and 503) provide necessary criteria for sludge product treatment and usage. States have the option to either adopt federal standards or justify and adopt other equivalent or more restrictive use limitations.
Methods generally approved as Process to Further Reduce Pathogens (PFRP), the most substantial pathogenic organism reduction option, can be summarized as thermal treatments from external heat sources such as incinerators and dryers (pressurized or at ambient atmospheric pressures). Heat treatment for pathogenic reductions also include thermophilic decomposition (composting) and thermophilic aerobic digestion which utilize temperature increases from biologic activity to reduce pathogenic organisms to PFRP standards. Non-thermal processes for PFRP treatments include chemical disinfection and radiation of sludge solids (electron, gamma ray, ultraviolet).
The reuse of sludge is also limited by concerns other than pathogenic content. End product qualities and raw waste constituents (heavy metals) have frequently affected the ability to use the end product in certain environments. While not a significant problem in sewage sludges, soluble arsenic compounds may be of concern in specialized situations.
All of the approved processes involve the use of substantial amounts of land or equipment to hold large bodies of waste for long holding periods or the application of heat from external sources to reduce the holding time during treatment.
Other processes for treatment of waste can be utilized if the use proves that the process results in effective removal of pathogens from the waste.
STATEMENT OF THE PRIOR ART
Some of the other processes for reducing the pathogen level of solid waste are disclosed in the patent literature.
Meehan, et al. (U.S. Pat. No. 4,793,927) chemically disinfects sewage with an ammonia source and converts it into an impermeable, friable mass with cement and silicate. A strongly alkaline environment kills bacteria and viruses. No thermal process is involved and the resulting alkaline product is not suitable for use as an agricultural amendment to soils in the western United States which are usually alkaline.
Webster, et al. (U.S. Pat. No. 4,028,130) discloses treatment of municipal sludge by incorporating the sludge in a hardenable composition including lime, fly ash and in some cases alkaline earth metal sulfates and/or soil or other inert additives. The material cures in air over a long period.
Boyko (U.S. Pat. No. 4,191,549) combines sludge with carbonized cellulose and coal ash to produce a grainy product that is sterilized by chlorination.
Bolsing (U.S. Pat. No. 4,997,486) produces a product containing calcium sulfate useful as a fuel or cement clinker by combining used hydrocarbon oils with waste sulfuric acid and powdered limestone or fly ash to form a solid mass. Disinfection is not an issue.
King (U.S. Pat. No. 4,615,809) stabilizes hazardous industrial organic sludges by combining the sludge with Portland cement, fly ash, calcium sulfate and lime to form a product with soil-like consistency. Again disinfection is not discussed.
Pichat (U.S. Pat. No. 4,547,290) treats very acidic or basic liquid wastes by first dispersing clay in the waste at a temperature between 0 and 150 degrees Celsius followed by adding lime and then a hydratable binder.
There are several patents which utilize sterilization and disinfection of sewage sludge with lime or other calcium oxide sources.
Wurtz dewaters sludge to form a cake and reacts the cake with calcium oxide in a high intensity reactor to produce a stabilized sludge pellet. The addition of lime results in an exothermic reaction raising the temperature to 170 degrees Fahrenheit to 210 degrees Fahrenheit. The pellet is burned to produce heat and the calcium oxide is separated from the ash and recycled. The process requires a special reactor for intimate mixing of the dewatered sludge and lime. Lime is an expensive reagent and the resultant product is alkaline.
Nicholson, et al. (U.S. Pat. No. 4,554,002) convert sewage sludge into a useful fertilizer by treating the sludge with lime and cement kiln dust. The alkalinity of the mixture and the exothermic heat developed by hydration of the lime reduce the level of pathogens and may meet PFRP criteria. Again the resulting product is alkaline and is not useful with alkaline soils. The process requires the use of lime and/or kiln dust having high calcium content in order to generate the necessary pH and temperature for disinfection. High lime content kiln dusts are expensive and are in limited supply.
STATEMENT OF THE INVENTION
The present invention provides a process for disinfection of sludge and other feces contaminated solid wastes that is based on the use of readily available and inexpensive materials. The process of the invention effectively eliminates at least 90% of pathogenic organisms. The resulting product is safe for application to land for grazing and crop production. The process of the invention reduces to the point of elimination the presence of viable ascarid eggs, ova and cysts in the finished product. The process can be readily controlled to produce products useful on any type of soil. The process is also extremely flexible. The proper selection of reactants can result in formation of soil amendments, fertilizers and agricultural minerals. The end products can also be useful in road construction or as industrial chemicals.
The process of the invention utilizes simple equipment for a short holding time to pasteurize the solid waste. The use of inexpensive starting materials and the generation of saleable end products provides a substantial economic benefit to waste generators and to waste converters to process the waste.
The process of the invention can also be readily modified by selection of reagents and additives to eliminate or reduce to safe levels soluble heavy metal ions which otherwise may limit use of the end product or reduce its selling price.
The solid waste treatment process of the invention is capable of handling a large volume of sewage sludge, septages, residuals or manures in a cost effective manner. The process can be readily practiced at a waste treatment plant or in a separate facility operated by a third party.
The solid waste disinfection process of the invention operates by treating the sludge with an acid-base pair that exothermically react to generate a temperature for a time sufficient to reduce the pathogens in the waste by at least about 90%. The acid-base pair may also generate a by-product that chemically disinfects the waste. Preferably the process kills, inactivates or destroys substantially all pathogenic organisms contained in the waste.
The acid and/or base utilized in the process affects the properties and value of the end product. For example, the use of nitrogen or phosphorous containing acid-base pairs adds fertilizer value. The formation of calcium sulfate from the acid-base pair provides a soil amendment. The adjustment of pH by selection of a suitable strong acid provides a product useful to reduce alkalinity of alkaline soils. The acid-base pair can be selected to generate a daughter compound that acts as a chemical disinfectant such as sulfur dioxide, ammonia, chlorine or bromine. The acid-base pairs can also generate species that bind or reduce the solubility of certain heavy metals. Preferred acid base pairs are Lewis acids and Lewis bases.
End properties of the produce such as volume and physical handling or physical properties can deleteriously affect use of the product in certain applications and therefore reduce its value. The properties can also effect handling, transportation costs and costs associated with the end use application.
The acid-base pair can be selected to provide a product having sludge-like properties or further dried to a soil-like material. The acid-base pair can also be selected to provide agglomeration of the product into a friable mass useful to aid in soil aeration by selection of a pozzolanic source of base or other binder-type reagent. Bound forms of calcium oxide in fly ash appear to provide slow release of calcium which contributes to the necessary holding time at temperature to pasteurize the solid waste.
These and many other features and attendant advantages of the invention will become apparent as the invention becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a simplified system for disinfecting sewage sludge and converting it to an agricultural product in accordance with the invention;
FIG. 2 is a schematic view of a batch system for disinfecting solid waste in accordance with the invention;
FIG. 3 is a schematic view of a semi-continuous system for thermal pasteurizing of solid waste according to the invention;
FIG. 4 is a series of curves showing the temperature history of water, sulfuric acid-fly ash and sulfuric acid-fly ash and sewage sludge mixture; and
FIG. 5 is a chemical reaction sequence showing use of the acetic acid-lime base pair to treat solid waste.
CITED REFERENCE
1. Kirk-Othmer, "Concise Encyclopedia of Chemical Technology", John Wiley & Sons, 1985.
2. M. J. Pelczar and R. D. Reid, "Microbiology" 3rd Ed., McGraw-Hill, 1975.
DETAILED DESCRIPTION OF THE INVENTION
The solid waste (SW) treatment process of the invention can be represented by the following reaction:
A+B+SW+P→AB+RP≦0.1P
The reaction of an acid (A) and base (B) in presence of solid waste containing pathogens (P) results in formation of a salt (AB) and a reaction product (RP) containing no more than 10% of the pathogens (P) present in the waste.
Solid waste containing fecal matter can be municipal sewage sludge, waste treatment residual, septage or manure. The solids content of the waste can be from 3 to 85% by weight, usually 10-30% by weight. The solid waste suspension is usually present in an amount from 10 to 40%. The amount of acid and base depends on the strength of the acid and base and the exothermic heat of reaction developed by the acid-base pair and any other exothermic heat developed such as on hydration of the acid or base. Generally the acid is present in an amount from 5-25% by weight and the base in an amount from 10-40% by weight. The acid-base should be present in amounts within ±5 to 10% of neutralization. An excess of acid is required for agricultural amendment to alkaline soils.
The preferred acids are strong mineral acids, although organic acid such as acetic acid may be utilized. Acids introducing hazardous materials such as arsenic containing acids or hydrofluoric acid should be avoided. A table illustrating representative acids follows.
TABLE 1______________________________________H.sub.2 SO.sub.4 Sulfuric Acid (conc. and/or dilute)H.sub.2 SO.sub.4 + SO.sub.3 Oleum (> 100% by weight, fuming H.sub.2 SO.sub.4)SO.sub.3 Sulfur Trioxide (Sulfuric Anhydride)H.sub.n +.sub.2 P.sub.n O.sub.3n+1 Phosphoric Acids (Conc. and/or dilute)n = 1 Mono-(ortho) - Phosphoric Acid .sup. = 2 di-(pyro) - Phosphoric Acid .sup. = 3 tri (tripoly) - Phosphoric Acid .sup. = 4 Tetra - Phosphoric Acid .sup. = n Polyphosphoric Acid (1) P. 870H.sub.2 SO.sub.3 Sulfurous Acid (conc. and/or dilute)SO.sub.2 Sulfur DioxideHNO.sub.3 Nitric Acid (conc. and/or dilute)CH.sub.3 CO.sub.2 H Acetic Acid (Glacial, 99.8% and/or dilute)HCl Hydrochloric Acid (conc. and/or dilute)______________________________________
Strong inorganic bases are also preferred though weaker bases can be utilized. Representative bases are listed in the following table:
TABLE 2______________________________________NaOH Sodium HydroxideKOH Potassium HydroxideCa(OH).sub.2 Calcium HydroxideMg(OH).sub.2 Magnesium HydroxideCaO Calcium OxideMgO Magnesium OxideNH.sub.3 AmmoniaNH.sub.4 OH Ammonium Hydroxide______________________________________
Other minerals and/or by-products that contain these bases, E.G., Fly ash, cement kiln dust, Arco "Gyp" (calcium sulfite), etc. can also be utilized.
Representative Acid-Base pair reactions follow:
TABLE 3______________________________________ACID (A) BASE (B) PRODUCTS (AB)______________________________________H.sub.2 SO.sub.4 NaOH NaHSO.sub.4, Na.sub.2 SO.sub.4, H.sub.2 OH.sub.2 SO.sub.4 KOH KHSO.sub.4, K.sub.2 SO.sub.4, H.sub.2 OH.sub.2 SO.sub.4 Ca(OH).sub.2 Ca(HSO.sub.4).sub.2, CaSO.sub.4.xH.sub.2 O, H.sub.2 OH.sub.2 SO.sub.4 Mg(OH).sub.2 Mg(HSO.sub.4).sub.2, MgSO.sub.4.xH.sub.2 O, H.sub.2 OH.sub.2 SO.sub.4 CaO Ca(HSO.sub.4).sub.2, CaSO.sub.4.xH.sub.2 O, H.sub.2 OH.sub.2 SO.sub.4 MgO Mg(HSO.sub.4).sub.2, MgSO.sub.4.xH.sub.2 O, H.sub.2 OH.sub.2 SO.sub.4 NH.sub.3 NH.sub.4 HSO.sub.4, (NH.sub.4).sub.2 SO.sub.4H.sub.2 SO.sub.4 NH.sub.4 OH NH.sub.4 HSO.sub.4, (NH.sub.4).sub.2 SO.sub.4, H.sub.2 OSO.sub.3 same sulfite reaction products as H.sub.2 SO.sub.4______________________________________
Other mineral or salts that can be added to the reacting mixture or substituted for all or a part of the base or acid are listed below:
TABLE 4
Apatite--A natural calcium phosphate (usually containing fluorine) e.g., Ca 10 F 2 (PO 4 ) 6 , Dolomite, CaSO 3 , K 2 SO 3 , Na 2 SO 3 , NH 4 HSO 4 , (NH 4 ) 2 SO 4 , KHSO 4 , K 2 SO 4 , KH 2 PO 4 , K 2 HPO 4 , K 3 PO 4 , NH 4 H 2 PO 4 worlds leading phosphate fertilizer, (NH 4 ) 2 HPO 4 worlds leading phosphate fertilizer, (NH 4 ) 3 PO 4 , KCl, NH 4 Cl, CaCl 2 , KNO 3 , NH 4 NO 3 , Ca(NO 3 ) 2 , S, Urea, NaNO 3 .
These salts or minerals may contribute to the exothermic reaction and when they are present in amounts which raise the total nitrogen or phosphorous content at least 5% by weight, the product can be marketed as a fertilizer. Dolomite adds magnesium values to the end product.
The reaction of apatite with concentrated sulfuric acid follows
Ca.sub.10 F.sub.2 (PO.sub.4).sub.6 +10H.sub.2 SO.sub.4 +10xH.sub.2 O→6H.sub.3 PO.sub.4 +10CaSO.sub.4.x H.sub.2 O+2HF (1) p. 467
Where x=0.5 to 0.7, or 2.0
Strongly Exothermic
The phosphoric acid reaction product is a fertilizer and calcium sulfate dihydrate, gypsum, is a soil amendment. The phosphate ion may bind and precipitate heavy metals such as cadmium and arsenic. Since the reaction can liberate hydrogen fluoride (HF) it should be monitored. Since the amount of fluorine in apatite ore can vary, the ore should be assayed before use in the treatment of solid waste.
Solid wastes containing water soluble arsenic compounds may be treated with sulfuric acid and calcium hydroxide in the presence of sulfate and ferrous and/or ferric ions to form water-insoluble arsenic salts as disclosed in U.S. Pat. No. 4,118,243. Lead and cadmium wastes are removed from incinerator ash by use of phosphoric acid and lime as disclosed in U.S. Pat. No. 4,737,356. U.S. Pat. No. 3,837,872 discloses reducing solubility and mobility of certain heavy metals in sludge. The disclosures of these patents are incorporated herein by reference.
The process of the invention also contemplates the presence of gaseous species which contribute to disinfection. Gases such as oxygen, ozone, steam ammonia, sulfur dioxide or chlorine can be bubbled through the suspension. Gaseous species such as ammonia or sulfur dioxide can be generated as a result of reaction of the acid-base pair with each other or with components of the sludge or other solid waste. SO 2 can be generated as a chemical disinfectant by the thermal decomposition of salts such as sodium meta-bisulfite which can be present in amounts from 0.1 to 5% by weight or more.
The generation of gaseous, dissolved or solid compounds that enhance pathogen reduction may permit the use of lower temperatures and/or shorter treatment intervals. It is believed that petroleum coke and fly ash with high calcium sulfite content from desulferization process when reacted with sulfuric acid will produce significant evolution of sulfur dioxide which can achieve disinfection of sewage sludge and may not require as high a temperature as thermal pasteurization to achieve disinfection. The use of low acid pH is believed to cause chemical disinfection just as higher pH does as disclosed in U.S. Pat. No. 4,793,927.
The characteristics of the end product can be modified by including 1 to 30 percent by weight of an agglomerating agent. A preferred agent is a pozzolanic material which causes aggregation of particles as it cures. Pozzolanic materials generally include aluminosilicate structures which can bind together especially in the presence of lime, calcium sulfate or other basic substances. Certain materials such as fly ash, cement klinker and kiln dust have pozzolanic activity and contain sufficient base such as calcium oxide and/or calcium hydroxide that which reacted with an acid, generate exothermic heat sufficient to pasteurize sewage sludge.
Fly ash utilized in the invention demonstrates slow release of base. This contributes to maintaining the suspension at minimum temperature for at least 30 minutes. The fly ash need only contain a moderate amount of calcium oxide, generally from 10-25% by weight of free CaO and 30-60% total CaO. This is in contrast to the N-Viro process disclosed in the Nicholson patent which requires a very high content (at least about 50% free lime) in the kiln dust or the addition of free lime in order to generate the pH and temperature necessary for chemical disinfection.
The fly ash is preferably unquenched since quenching would hydrate the metal oxides and decrease the exothermic heat contributed by hydrating the salts. Part of the fly ash can be substituted with up to 50% by weight of other calcium sources or other materials with pozzolanic activity such as kiln dust or cement clinker dust. Unquenched F-type fly ash (UQFA) having a high pH of from 11-13 is preferred for use on this invention. Another measure of base content is the ΔT generated on reaction of 60 g of fly ash or other base with 100 ml of H 2 O. The fly ash utilized in the process of the invention preferably has a ΔT in water of at least 50 degrees Celsius. The chemical analysis of a UQFA fly ash follows:
TABLE 5______________________________________Constituents WT. % As Received______________________________________Calcium Oxide as CaO (free) 16Aluminum as Al.sub.2 O.sub.3 4.8Iron as Fe.sub.2 O.sub.3 4.2Magnesium as MgO 2.5Acid Insoluble (silica) 36Total Alkalinity as CO.sub.2 34Calcium as CaO 35Potassium as K.sub.2 O 0.30Total Sulfate as SO.sub.4 10.3Gypsum as CaSO.sub.4.2H.sub.2 O 18.04Moisture None Detected______________________________________
The following examples of disinfection of solid waste were conducted. The examples were all monitored to determine whether they met EPA criteria for a PFRP pasteurization--a minimum of 70 degrees Celsius (158 degrees Fahrenheit) for a minimum of thirty minutes. Sewage sludges are appropriately stored to prevent odor generation and regrowth of pathogenic organisms.
The process of the invention can be practiced in several different ways. In the simplest form as shown in FIG. 1, dewatered sewage sludge 10 is mixed with an acid 12 and a base 14 in an insulated mixer 16. The mixture 17 is conveyed by a conveyer 18 into the body 20 of a truck 22. The mixture 17 is maintained in the truck body 20 for a minimum of time at a temperature sufficient to pasteurize the mixture. The pasteurization reaction may proceed while the truck 22 travels on a highway 24 to a field 26. The pasteurized product 27 can be loaded into the hopper 25 of a spreader 28 which spreads the mixture onto the field containing crops 29. The pasteurized product 27 need not be spread immediately. The product 27 can be stored in a bin or out in the open until needed.
The process operates autogenously. The heat needed is developed by the exothermic reactions occurring on mixing the acid and base with the sludge. Pressure is not required. However, pressure may be beneficial and can also be autogenously developed by placing the reaction mixture in a closed reaction vessel 40 as shown in FIG. 2. A batch process proceeds by feeding sludge 42 from tank 44, acid 46 from storage tank 48 and base 50 from storage hopper 52. The reaction vessel 40 can be equipped with a stirrer 54. The vessel may contain an insulation jacket 56 or a heating jacket, not shown, if it is necessary to add heat to raise the temperature or shorten the holding time. An insulated lid 57 may contain a temperature sensor 58, and a pressure release valve 60. Off gases such as SO 2 , H 2 S or NH 3 can be vented to an absorber or scrubber 62. The finished product can be removed through outlet 64 when valve 66 is open.
A semi-continuous system is illustrated in FIG. 3. Acid 100 such as concentrated sulfuric acid from storage tank 102 and sewage sludge 104 from hopper 106 are fed into insulated mixer 108 containing a mixing blade 110 is connected to a shaft 113 and is driven by a motor 211. The sludge-acid 111 mixture feeds through outlet 210 into a mixer such as an insulated pug mill 112. Granular base 114 such as fly ash is fed from hopper 115 into the forward end 116 of pug mill 112. The pug mill 112 contains paddles 117 mounted on a shaft 119 driven by a motor 121. The paddles 117 push the material forward as they cut through the fly ash, acid, sewage sludge mixture. The mixture is intimately mixed in the pug mill and exothermic reaction begins. The hot mixture proceeds through the outlet 129 and into the inlet 122 of a well insulated rotary oven 118. The rotary oven 118 can contain a spiral thread 123 that moves the mixture forward as the oven 118 rotates. The rotary oven 118 has a long residence time, at least sufficient enough to allow the mixture to react and sterilize at least 90% of the pathogens in the sludge. Preferably all the pathogens in the sludge are killed. Gases evolved in the oven can be recycled through line 120 to the inlet 122 to the rotary oven. Some of the gases can be withdrawn through the outlet 124 by means of a pump 126 and are absorbed in the liquid in gas absorber 128.
In the case of sulfuric acid, the H 2 S and SO 2 are absorbed into an organic amine or a caustic such as potassium hydroxide. The absorption scrubber reactions for KOH are as follows:
SO.sub.2 +KOH--KHSO.sub.3
H.sub.2 S+KOH--K.sub.2 S+H.sub.2 O or KHS+H.sub.2 O
The spent liquid in the absorber 128 can be recycled to the mixer 108 through outlet 134 in order to incorporate the potassium salt in the mixture. The disinfected mixture exits the rotary oven through an outlet 133 which connects to inlet 135 to an insulated holding vessel 137. The reaction product 139 can be recovered through outlet valve 150 as needed and subdivided in mill 152 to form a granular product 154.
The granular product is conveyed by trough conveyer 156 to the bagging station 158 where it is packaged in bags 160.
The rotary oven can be replaced with an insulated extruder. The extruder can have a resin fiberglass barrel which will provide heat insulation and self lubrication for the slurred mixture. A suitable conveyor is a 24 inch diameter HETRON 980 resin fiberglass conveyor that can move 1920 pounds/min at 15 rpm.
EXAMPLE 1
Sewage sludge (SS, 250 gm, 20% solids) is placed in a Nalgene reaction chamber followed by sulfuric acid (93%, d 1.8279, 35 mL, 64 gm) and the contents are rapidly mixed. Then fly ash (75 gm, 25% CaO) is added portionwise (about three equal amounts), each time mixing rapidly until a homogenous slurry is obtained (about 30 seconds). The chamber is then sealed off by the application of a styrofoam lid equipped with a thermometer. When the thermometer reaches 82 degrees Celsius (180 degrees Fahrenheit) a stopwatch is activated followed by the recording of temperature as a function of time (minutes). The amount of time that the temperature exceeded 82 degrees Celsius (180 degrees Fahrenheit) was ninety (90) minutes. This is well in excess of the 30 minutes at 82 degrees Celsius required by the EPA for pasteurization. The product was grey and friable. It had a slight odor of manure after drying at 45 degrees Celsius (113 degrees Fahrenheit) after grinding. The finished product was granular in texture.
The dried product was analyzed for sodium and calcium by ICP. The gypsum (CaSO 4 .2H 2 O) content was calculated at 36-64%. Sodium concentration was found to be 2,618 mg/Kg.
The presence of other metals and metalloids in the dried product was determined to be as follows:
TABLE 6______________________________________ Regulatory CriteriaCON- SAMPLE STLC TTLCSTITUENT RESULTS UNITS mg/L mg/kg______________________________________Antimony BDL* mg/kg 15. 500.Arsenic BDL mg/kg 5.0 500.Barium BDL mg/kg 100. 10,000.Beryllium BDL mg/kg 0.75 75.Cadmium 11.5 mg/kg 1.0 100.Chromium 46.9 mg/kg 5.0 500.Cobalt BDL mg/kg 80. 8,000.Copper 192.1 mg/kg 25. 2,500.Lead 149.7 mg/kg 5.0 1,000.Molybdenum BDL mg/kg 350. 3,500.Nickel 34.9 mg/kg 20. 2,000.Selenium BDL mg/kg 1.0 100.Silver 16.7 mg/kg 5.0 500.Thallium BDL mg/kg 7.0 700.Vanadium 87.3 mg/kg 24. 2,400.Zinc 249.5 mg/kg 250. 5,000.______________________________________ *BDL = Below Detection Limits
The internal temperature of the contents as a function of time were determined. The composition of the mixture is as follows:
______________________________________ SEWAGE SLUDGE H.sub.2 SO.sub.4 (1937) FLY ASH WATERSAMPLE gm gm gm gm______________________________________D 0 64 75 200E 250 64 75 0F 0 0 0 250______________________________________
The temperature curves are shown in FIG. 4. A second derivative plot, not shown, was utilized to determine the inflection change.
The water curve, F, demonstrates classical Newtonian cooling. The curve is concave up in form. Both curves for the D and E curves containing fly ash-acid mixtures are concave down at the top, then proceed through an extended inflection transition range and then to a concave up region. The D and E curves are non-Newtonian. The concave down region shows heat evolution for 1 hour 18 minutes demonstrating the encapsulation of the calcium oxide and calcium hydroxide bases in fly ash and the slow release. Newtonian cooling does not start until after the inflection transition range--the portion of the curves which are concave up in shape.
Example 1 can be repeated substituting 65% by weight of dewatered septage or cow manure (20% solids) for the sewage sludge. The exothermic reaction between sulfuric acid and the fly ash would proceed to a temperature for a time sufficient to pasteurize the septage or manure and form an agglomerated product. A granular product is formed after drying and grinding. Concentrated phosphoric acid and lime exothermically react with sewage sludge to form pasteurized sludge and calcium phosphate. The calcium phosphate can bind ions such as lead, arsenic or cadmium. The acid-base pair, glacial acetic acid and hydrated lime exothermically react in the presence of sewage sludge to pasteurize the sludge and form calcium acetate. Limestone generated in situ by the thermal decomposition of calcium acetate as in a furnace chamber, reacts with SO 2 such as from stack gases to form calcium sulfite and calcium sulfate according to the reaction shown in FIG. 5.
EXAMPLE 2
Example 1 was repeated in a more insulated reaction chamber. The time at 82 degrees Celsius (180 degrees Fahrenheit) was increased from 91 minutes to 106 minutes.
EXAMPLE 3
350 grams of sewage sludge (20% by weight) solids and 95 grams of UQFA were combined with 93% sulfuric acid and equivalent amounts of concentrated phosphoric and glacial acetic acid in the following proportions.
TABLE 7______________________________________ 93% H.sub.2 SO.sub.4 H.sub.2 SO.sub.4 H.sub.3 PO.sub.4 or HOACSamples Grams Mole % Mole %______________________________________5,10 8 12.5 87.56,11 16 25.0 757,12 32 50.0 508,13 48 75.0 259,14 59.6 90 10______________________________________
HCl could not be combined with sulfuric acid since it is insoluble in concentrated sulfuric acid. The temperature histories of these experiments follow:
TABLE 8__________________________________________________________________________ Glacial Acetic MinutesH.sub.2 SO.sub.4 H.sub.3 PO.sub.4 Acid HCL Sewage Fly Max. at Temp.93% 85% 99% 34-37% Sludge Ash Temp. above# gm # gm # gm # gm # gm # gm °C. 82° C.__________________________________________________________________________1 64.0 350 95 99.5 802 70.04 350 95 59.8 03 73.03 350 95 72.9 04 120.72 350 95 67.2 05 8 61 350 95 60.1 06 16 53 350 95 63.9 07 32 35 350 95 71.8 08 48 17.5 350 95 80.8 09 57.6 7 350 95 92.0 5110 8 64 350 95 74.1 011 16 55 350 95 72.5 012 32 37 350 95 79.0 013 48 18.3 350 95 83.2 2114 57.6 7.3 350 95 96.5 68__________________________________________________________________________
Phosphoric acid-fly ash base pair did not achieve a temperature of 70 degrees Celsius. When about one-half of sulfuric acid is replaced with an equivalent amount of phosphoric acid, temperatures above 70 degrees Celsius are achieved. Glacial acetic in mixture from 0 to 100% with sulfuric acid achieves a temperature of 70 degrees Celsius and in mixture with sulfuric acid containing no more than about 25% equivalent amount of acetic acid achieves a temperature over 80 degrees Celsius.
EXAMPLE 4
Sewage sludge (300 gm) was placed in an insulated reaction vessel. Sulfuric acid (93%, 64.85 gm) was added, followed by the addition of ARCO "Gypsum" (75 gm, delta T=0.8 C, pH=12.9) to the vessel and mixed thoroughly. The maximum temperature attained was 70.8 C along with the liberation of much SO 2 . When the same procedure is carried out substituting unquenched fly ash for ARCO "Gypsum", the maximum temperature is about 95 degrees Celsius. ARCO "Gypsum" was also analyzed for calcium (via ICP) and sulfate (gravimetrically) and the percent calcium sulfate dihydrate (gypsum) was calculated as 53.00 and 2.49%, respectively. The large difference in percent gypsum calculated from the two different techniques reveals that the material must contain mostly calcium sulfite rather than calcium sulfate. Calcium sulfite or other metal sulfite could be utilized as an additive to an exothermic formulation to provide chemical disinfection by the SO 2 produced by acidification of the sulfite.
EXAMPLE 5
Four experiments were run to determine the effect of sodium meta-bisulfite (Na 2 S 2 O 5 ) on sterilization of sewage sludge. The components were placed inside an insulated reaction vessel in the following order: fly ash, sodium metabisulfite, sewage sludge and last sulfuric acid. The mixture was then rapidly and thoroughly stirred, the chamber sealed and the temperature recorded as a function of time. After 5 hours the vessels were opened and the contents were transferred to Whirl-Pak bags and sealed (double bagged). The bags were placed in insulated mugs and quickly transported to an offsite location where an insulated container (equipped with Blue Ice) had been frozen for 24 hours. The bags were transferred to the insulated container, sealed and transported to a lab for pathogen analysis. The composition and thermal response of the four samples is summarized in the following table:
TABLE 9______________________________________ Min. at Sewage H.sub.2 SO.sub.4 temp. aboveSample Sludge (93%) Fly Ash Na.sub.2 S.sub.2 O.sub.5 82° C.______________________________________A 250 gm Room temp.B 250 gm 35 mL Peak at 55 C.C 250 gm 35 mL 75 gm 1 hr., 32 min.D 250 gm 35 mL 75 gm 1 gm 1 hr., 36 min.______________________________________
Sulfuric acid alone, only raised the temperature to 55 degrees Celsius. Sulfuric acid and fly ash raised the temperature to above 82 degrees Celsius for 92 minutes. The addition of sodium meta-bisulfite raised the temperature to above 82 degrees Celsius for 96 minutes, an insignificant difference. However, substantial evolution of SO 2 was noted.
Pathogen analysis was initially conducted by inoculating a set of 15 tubes and allowing them to incubate. Sample B showed 5 positive tubes out of 15, Sample C showed 1 positive tube while Sample D showed no positive tubes. Temperature is apparently crucial to the process since Sample B only reached 55 degrees Celsius while Samples C and D reached 101.6 degrees Celsius and 101.8 degrees Celsius, respectively and remained above 82 degrees Celsius for over 90 minutes. The improvement of D appears to be due to the evolution of SO 2 from the sodium meta-bisulfite. Further data on pathogen testing is presented in the following table.
TABLE 10__________________________________________________________________________ SAMPLE A SAMPLE B SAMPLE C SAMPLE DSAMPLE UNTREATED TREATED TREATED TREATEDIDENTIFICATION SLUDGE SLUDGE SLUDGE SLUDGE__________________________________________________________________________FECAL COLIFORM 70,000,000 <200 <200 <200# PER 100 MLLOG MPN VALUE 7.85 2.3 2.3 2.3LOG REDUCTION NA 5.5 5.5 5.5LOG A/LOG B,C,DFECAL 9,000,000 <200 <200 <200STREPTOCOCCUS# PER 100 MLLOG MPN VALUE 6.95 2.3 2.3 2.3LOG REDUCTION NA 4.7 4.7 4.7LOG A/LOG B,C,D__________________________________________________________________________
Further experiments were conducted to determine the effect of varying the amounts of concentrated sulfuric acid, unquenched fly ash and sodium meta-bisulfite added to dewatered sewage sludge (20% solids). The composition of the initial and final products and time pathogen content of time products are presented in the following tables:
TABLE 11______________________________________ UQFASAM- SS, 93% .increment.1 = 23 C.PLE gm WT, % H.sub.2 SO.sub.4 gm WT. % gm WT %______________________________________E 60 100F 250 98.96 2.64 1.04G 250 97.98 5.15 2.02H 250 95.98 10.48 4.02I 250 91.97 21.84 8.03J 250 83.95 47.81 16.05K 250 79.31 64.21 20.37L 300 68.17 64.02 14.55 75.06 17.06M 350 71.42 63.99 13.06 75.02 15.31N 350 70.71 64.04 12.94 79.97 16.16O 350 70.00 64.03 12.81 84.97 16.99P 350 69.28 64.20 12.71 90.06 17.83Q 350 68.62 64.01 12.55 95.06 18.64R 350 68.75 64.05 12.58 95.01 18.66S 400 71.42 63.99 11.43 95.06 16.97______________________________________SAM- Sodium Meta- P + SS (Wet) P + SS (Dry)PLE Bisulfite gm Wt. % gm gm______________________________________E 312.09 74.31F 215.80 52.30G 202.33 52.03H 209.39 57.90I 214.07 66.10J 224.94 87.39K 0.99 0.31 231.92 104.82L 0.99 0.23 358.29 178.82M 1.02 0.21 397.50 190.23N 0.99 0.20 403.99 194.33O 1.00 0.20 414.05 200.29P 0.97 0.19 419.70 204.97Q 0.98 0.19 565.92 358.30R 579.33 364.49S 0.99 0.18 608.15 367.04______________________________________SAM-PLE H.sub.2 O, gm P gm pH Dry Wt. % H.sub.2 O Wt. % Red______________________________________E 237.78 13.70 6.55 79.69 -79.69F 163.50 13.66 5.97 80.88 -80.88G 150.30 13.75 5.29 79.70 -79.70H 151.49 14.12 3.49 77.58 -77.58I 147.97 14.17 1.03 74.02 -74.02J 139.55 14.27 -0.27 65.29 -65.29K 127.10 13.88 -0.52 58.29 -58.29L 179.47 13.78 2.70 52.09 -52.09M 207.27 13.80 3.18 54.02 -54.02N 209.67 14.18 3.38 53.79 -53.79O 213.76 14.14 3.99 53.45 -53.45P 214.73 14.05 4.90 52.93 -52.93Q 207.62 167.31 6.50 52.09 -52.09R 214.84 164.32 6.43 51.77 -51.77S 241.11 165.31 6.50 54.44 -54.44______________________________________ # Fecal Coliform Fecal ColiformSAMPLE Per 100 ml Log [FC] Log Reduction______________________________________E 220,000,000 8.34F 130,000,000 8.11 1.03G ≧1,600,000 6.2 1.35H 1,700 3.23 2.58I <200 2.3 3.63J <200 2.3 3.63K <200 2.3 3.63L <20 1.3 6.42M <20 1.3 6.42N <20 1.3 6.42O <20 1.3 6.42P <20 1.3 6.42Q <20 1.3 6.42R <20 1.3 6.42S <20 1.3 6.42______________________________________ # Fecal Fecal Strep. Maximum Temp. C./SAM- Strep. per Log Log Re- Time withPLE 100 ml [FS] duction Temp. > 82° C.______________________________________E 3,000,000 6.48 ControlF 2,400,000 6.38 1.02 20G ≧1,600,000 6.2 1.05 21.5H 30,000 4.48 1.45 24I 50,000 4.70 1.38 26J <200 2.3 2.82 39K <200 2.3 2.82 57L <20 1.3 4.98 1 hr., 21 min. 95.2M <20 1.3 4.98 1 hr., 3 min. 91.0N <20 1.3 4.98 1 hr., 1 min. 91.0O <20 1.3 4.98 1 hr., 4 min. 91.5P <20 1.3 4.98 1 hr., 4 min. 95.5Q <20 1.3 4.98 1 hr., 18 min. 96.6R <20 1.3 4.98 1 hr., 16 min. 95.5S <20 1.3 4.98 0 hr., 57 min. 89.5______________________________________
Again acid alone (E-J) or acid and sodium meta-bisulfite did not achieve a minimum temperature of 82 degrees Celsius.
Further samples of sewage sludge were treated with sulfuric acid and meta-bisulfite or ARCO GYP. The materials were placed in an insulated reaction vessel for 30 minutes at 82 degrees Celsius. Composition of the samples U, V, W and X follow:
TABLE 12__________________________________________________________________________ 93% ARCO.sup.aSS, Wt. H.sub.2 SO.sub.4 Wt. UQFA, Wt. Na.sub.2 S.sub.2 O.sub.5, Wt. Gyp Wt. MAX.gm % gm % gm % gm % gm % TEMP__________________________________________________________________________U 30068 64 15 75 17 1 <1 96 C.V 30068 64 15 75 17 95.5 C.W 40072 64 11 95 17 91 C.X 30068 64 15 75 17 67.8 C.__________________________________________________________________________ .sup.a Note that ARCO "GYP" is by in far composed of CaSO.sub.3 with very little CaSO.sub.4.
TABLE 13______________________________________ U V W X______________________________________Dry Weight 227.33 235.47 278.05 203.77Product, gpH 2.58 2.50 3.64 1.00______________________________________
Sample T was untreated. Sample T, U, V, W and X were tested for Most Probable Number (MPN) analysis results follow:
TABLE 14______________________________________UNTREATED SEWAGE SLUDGESAM- # Fecal Coliform LOG # Fecal Strep LOGPLE Per 100 gm [FC] Per 100 gm [FS]______________________________________T 2300 3.36 140,000 5.______________________________________
TABLE 15______________________________________30 MINUTE TREATED SEWAGE SLUDGE# Fecal FecalColiform Coliform # Fecal FecalPer LOG Log Re- Strep Per LOG Strep Log100 gm [FC] duction 100 gm [FS] Reduction______________________________________U <200 2.30 1.06 <200 2.30 2.85V <200 2.30 1.06 <200 2.30 2.85W <200 2.30 1.06 <200 2.30 2.85X <200 2.30 1.06 <200 2.30 2.85______________________________________
Samples U, V, W, and X upon treatment were submitted for Most Probable Number (MPN) analysis. Sample T, untreated sewage sludge, had unusually low counts relative to previous results. However, the Log Reductions for all samples exceeded two. Note that when ARCO "GYP" was substituted for fly ash the results were identical to all others, even though the maximum temperature was only 67.8 degrees Celsius. Bear in mind, also, that all samples were allowed to remain above 82 degrees Celsius for only 30 minutes. It is believed that the success of the ARCO "GYP" is due in large part to the in situ generation of sulfur dioxide.
Experiments were conducted to determine whether thermal disinfection temperatures can be achieved by reacting dilute acid with a source of lime such as fly ash.
EXAMPLE 6
Two 50 g samples of Pyro Pacific fly ash having ΔT in 100 ml of water of 30.8 degrees Celsius (FA-1) and (FA-2) 16.8 degrees Celsius respectively were combined with sulfuric acid having concentrations from 5 to 25%. The pH and penetrometer hardness were determined. Data follows:
TABLE 16______________________________________% H.sub.2 SO.sub.4 5 10 15 20 25______________________________________T Min. 35.6 C. 68.8 C. 68.8 C. 72.3 C. 81.8 C.T Maximum 38.2 C. 77.0 C. 76.1 C. 78.1 C. 85.0 C.T Min. 31.3 C. 55.4 C. 69.6 C. 72.4 C. 80.0 C.T Maximum 35.0 C. 65.2 C. 75.9 C. 78.8 C. 85.8 C.______________________________________
The ΔT is a measure of calcium oxide content of the fly ash. A fly ash having a ΔT in water above about 15% by weight can achieve a pasteurization temperature of about 55 degrees Celsius with sulfuric acid as dilute as 10%. At 15% sulfuric acid, the suspensions of both fly ashes boiled vigorously. The pH of samples measured the next day were all basic except for the 2--2 sample which contained 25% sulfuric acid. The sulfuric acid concentration must be at least 25% if low pH products are desired. Penetrometer readings show a dramatic increase in hardness after 7 days. The product could be useful as a road base.
EXAMPLE 7
Experiments were also conducted with GWF fly ash. This fly ash (52 g) had a ΔT in 100 ml H 2 O of 77 degrees Celsius at 12 minutes and boiled. All contaminants with 15 to 30% H 2 SO 4 boiled vigorously and the Penetrometer readings were higher. GWF fly ash can be combined with lower ΔT fly ashes to increase the exothermic reaction with water and sulfuric acid.
It is to be realized that only preferred embodiments of the invention have been described and that numerous substitutions, modifications and alterations are permissible without departing from the spirit and scope of the invention as defined in the following claims. | Solid waste such as sewage sludge containing fecal matter is processed to reduce pathogens by at least 90% and converted to a useful product such as an amendment to agricultural land by combining the waste with an acid such as concentrated sulfuric and a base such as fly ash which exothermically react and thermally pasteurize the waste and add mineral value to the product. Pozzolanic materials, such as fly ash agglomerate the product and after grinding, the particles can aerate soil. The calcium oxide in fly ash reacts with sulfuric acid to form calcium sulfate dihydrate, a soil amendment. The amount of sulfuric acid can be controlled to provide a product with acid pH which is useful to neutralize alkaline soils such as those found in the Western United States of America. | 8 |
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to systems for controlling the stability of a vehicle, commonly known as ESP (Electronic Stability Program) systems.
In safety systems for vehicles it is necessary to be able to assess the behavior of the vehicle in real time. This is the basis of the so-called ESP systems for controlling stability. These systems currently rely on, inter alia, monitoring movements of the vehicle by installing sensors to measure the transverse acceleration of the vehicle and the yaw rate of the vehicle.
When moving under good safety conditions, that is, when the stability of the vehicle is not compromised, the vehicle obeys the driver's commands. If the driver, basically as a result of his handling of the steering wheel, drives the vehicle beyond the limits of stability, the vehicle will exhibit oversteering or understeering. The vehicle turns, that is, performs a yaw movement, in excess of that desired by the driver (oversteering) or less than desired by the driver (understeering).
Using a mathematical model of the tire and a mathematical model of the vehicle, and based on measurements supplied by sensors recording the actions of the driver of the vehicle (angle relative to the steering wheel, application of the brakes and accelerator) and speed sensors for the wheels, and from measurements of the transverse acceleration and yaw rate, an ESP system constantly calculates the forces at the center of the wheels and estimates the grip potential of the road surface as a function of the transverse acceleration. Furthermore, the ESP system evaluates the behavior of the vehicle, compares it to the behavior desired by the driver, and corrects this behavior if it establishes that the vehicle is not moving along a stable path.
However, the use of tire models can introduce a certain number of approximations into the overall model. Furthermore, the fact that a control system is based on the displacements of the vehicle necessarily leads to a response a posteriori, which can be effective only after a delay depending on the inertia of the vehicle. It can be seen from this that an ESP system, since its variables of state include measurements of the transverse acceleration and the yaw rate of the vehicle, first of all has to measure the displacement of the vehicle before deciding whether the displacement is within the bounds of stability or not, and can only then act on the operating means of the vehicle. Moreover, the currently available ESP system observes only the movements of the body of the vehicle without knowing specifically the exact reasons for the loss of control. The movements of the body of the vehicle are caused by contact between the tire and the ground.
The system will detect a displacement of the vehicle not in accord with the command given by the driver, more slowly the greater the inertia of the vehicle, and the necessary correction will be all the more difficult the greater the inertia. At the present time the operating means are basically the vehicle's brakes, controlled in this case wheel by wheel and outside the voluntary action of the driver, and the motive force, which can be reduced automatically by regulating the engine.
Furthermore, the detection of yaw movements requires the use of costly sensors. Also, existing systems have to estimate the grip of the wheels on the road surface in order to select the actuating parameters. This estimation deviates to a greater or lesser degree from the actual conditions.
The object of the present invention is to obviate the aforementioned disadvantages and, more particularly, to exclude completely the inertia of a vehicle in order to be able to act on the appropriate operating means so as to maintain the vehicle in a stable path in accordance with the driver's commands, by regulating the operating means in such a way that the actual forces acting at the center of each wheel correspond to the desired forces.
The invention provides a vehicle stability control system and a method for controlling the stability of a vehicle that have the advantage that they can be carried out without having to measure the yaw angle of the vehicle.
The invention relates to a vehicle comprising a body and at least one front ground contacting arrangement and at least one rear ground contacting arrangement, each ground contacting arrangement comprising in each case one wheel, each wheel comprising a pneumatic or non-pneumatic tire in contact with the ground, the vehicle having a characteristic time that is a function of its inertia and corresponds to the time phase shift in the manifestation of the cornering forces on the wheels in the front and in the rear, following a command from the driver of the vehicle, the vehicle being provided with operating means to act on the forces transmitted to the ground by each of the wheels.
In a vehicle the steering of the wheels produces a cornering force at the front, a movement of the vehicle body, followed by a cornering force at the rear. The cornering force of the rear wheel or wheels thus intervenes with a slight delay with respect to the command on the steering wheel. In order to establish more precisely the actions required to correct the path, the invention proposes to take into account this delay T as explained hereinafter.
According to a first aspect of the invention, the method comprises the following steps:
(a) measuring in real time the actual value of one variable selected in the group of the cornering force “Y” and the vertical load “Z” acting at the center of each of the front and rear wheels; (b) calculating in real time the desired value of at least one reference parameter, said at least one reference parameter being correlatable to the actual value, as a result of an action of the driver on the operating means and taking into account the load transfers on both sides of the mid plane of symmetry of the vehicle; (c) comparing said desired value of the reference parameter of step (b) to the actual value to determine whether the actual value is compatible with the desired value of the reference parameter; and (d) if the comparison of step (c) indicates that the actual value is not compatible, acting on the operating means such that the actual value is brought into substantial compatibility with the desired value of the reference parameter.
A preferred aspect relating to the specific application of the invention to vehicles each of whose axles comprises at least two ground contacting arrangements each comprising one wheel, is described hereinafter, the ground contacting arrangement being mounted on either side of the mid-plane of symmetry of the vehicle. This is the conventional arrangement in a four-wheeled touring vehicle. However, the invention is also applicable to two-wheeled vehicles, such as motorbikes, being noted that in this case the inertia of the body is considerably lower. Each ground contacting arrangement comprises a wheel, generally having a tire, which in this description means a pneumatic tire or non-pneumatic tire, in contact with the ground. The vehicle is provided with operating means to act on the forces transmitted to the ground by each of the wheels, such as brakes, means for steering the wheels, optionally selectively wheel by wheel, and distribution of the loads carried by each of the wheels.
The commands of the driver of the vehicle are intended to maintain the vehicle on a straight line path regardless of the ambient disturbances (for example sidewind gusts, change of the road grip on all or part of the vehicle), or are intended to cause the vehicle to execute a transverse displacement (change of lane for overtaking on a motorway) or to turn. Regardless of the operating means of the vehicle that are actuated by the driver (conventional steering wheel, operating lever as illustrated for example in patent application EP 0 832 807), the driver's wish in fact is to exert specific cornering forces or specific changes of these cornering forces.
The invention thus proposes to measure in real time the effective cornering forces, compare them to commands of the driver translated into cornering forces or changes in cornering forces, and thereby to control appropriate operating means available on the vehicle. In a first particular embodiment, said variable is the cornering force “Y” and said desired value of at least one reference parameter of step (b) is the desired cornering force “Y d ” at the center of each wheel. More particularly, step (c) further comprises generating an error signal representative of the magnitude and direction of the difference between the actual and desired cornering forces and step (d) comprises controlling said operating means to minimize said error signal.
In another particular embodiment, said variable is the cornering force “Y”, said operating means including a command for controlling the steering, step (a) comprises calculating in real time the effective yaw moment corresponding to the actual cornering forces “Y”, said desired value of at least one reference parameter of step (b) being the desired yaw moment, step (a) comprises measuring in real time a signal at the steering command and calculating the desired yaw moment “M d ”, and step (c) comprises utilizing said desired yaw moment “M d ” for comparison with the effective yaw moment of step (a). More particularly, step (c) further comprises generating an error signal representative of the magnitude and the direction of the difference between the effective yaw moment and the desired yaw moment “M d ”; and step (d) comprises controlling said operating means to minimize said error signal.
Accordingly, if the cornering force of the front axle has been saturated, the vehicle will understeer since the cornering forces of the front train are less than the forces desired by the driver (desired forces meaning forces corresponding to the actions by the driver on his steering wheel or on other steering commands available). An automatic action, for example of the type already known per se in conventional ESP systems (other types of actions will be discussed hereinafter) enables a resultant force to be exerted on the vehicle chassis in accordance with the driver's wishes and thus enables understeering to be avoided.
If on the other hand it is the cornering force of the rear axle that first becomes saturated, then the vehicle will oversteer since the cornering forces of the rear train are less than the forces desired by the driver. The automatic action enables a resultant force to be exerted on the vehicle chassis in accordance with the driver's wishes and thus enables oversteering to be avoided.
The above description refers to what is conventionally called the stationary state (or steady state). When considering a typical transient state involved in an emergency maneuver (avoiding an obstacle, changing lane), the speed of engagement of the steering wheel may be regarded as equivalent to a desired yaw moment acting on the vehicle. If the actual yaw moment is less than the desired yaw moment, the vehicle will not turn sufficiently. If on the other hand the actual yaw moment is greater than the desired yaw moment, the vehicle will turn too much.
According to yet another particular embodiment, said variable is the vertical load “Z”. More particularly, said operating means including a command for controlling the steering, and said desired value of at least one reference parameter of step (b) being the desired load “Z d ” at the center of each of the front and rear wheels, the method comprises a step for measuring in real time a signal at the steering command and calculating the desired loads “Z d ”. More particularly, step (c) further comprises generating an error signal representative of the magnitude and the direction of the difference between the actual loads “Z” and the desired loads “Z d ”; and step (d) comprises controlling said operating means to minimize said error signal.
The method according to the invention permits, if the cornering forces of one of the axles do not correspond to the desired cornering forces, or if the effective yaw moment is greater than the desired yaw moment, or if the vertical loads do not correspond to the desired vertical loads, the transmission of an action signal to the operating means in order to minimize the error signal without the need to establish such a signal, without the need to measure the yaw rate of the vehicle. Of course, such a method is compatible with measuring the yaw rate, particularly if it is desired to add redundancy terms to the calculations.
As can be seen, the invention provides a method for regulating a system for controlling the stability of a vehicle based on the forces acting at the center of each wheel of the vehicle. More specifically, the actions of the driver, whether they involve steering, accelerating or braking, will be reflected in forces (changes in forces) transmitted by the tires to the ground. Depending on whether or not these force variations are compatible with respect to the commands of the driver, it may be concluded whether or not the vehicle is stable. The origin of future displacements is found starting from the forces acting on the ground. In this way it is possible to correct the path of the vehicle much sooner and an ESP system, or more generally a stability control system, gains in fineness of correction. Both the safety and comfort of the driver and passengers are improved.
The estimation of stability criteria in real time, based on forces acting on the ground, enables the stability control of the path of a vehicle to be improved, the direct measurement of the force enabling, for example, the saturation point of the tire on each of the wheels to be monitored accurately regardless of the grip on the road surface, by detecting the occurrence of non-linearity between the developed cornering force and the sideslip angle of the tire in question, as well as non-linearity of the developed cornering force and the load applied to the tire.
The cause of loss of stability of the vehicle is mainly the fact that the tires are no longer able to correct the path, given the movement of the vehicle. Irrespective of the cornering force developed by the tires, this will never be able to counteract the forces of inertia. This may be due to a poor grip (wet road, (black) ice, snow, sand, dead leaves), to the fact that the tire is used by the driver under improper conditions (flat tire or underinflated tire), or to the fact that the vehicle is directly placed in a situation of excessive drift or sideslip that exceeds the physical limits of one or more of the tires. In this case it may be said that one or more of the tires reaches its saturation point.
The suspension bearings may be equipped with instruments, as proposed in patent application JP60/205037, which enables the longitudinal and transverse forces developed by the tire to be recognized easily by measurements made on the suspension bearings. Alternatively, the tire itself is equipped with sensors for recording the forces of the tire on the ground. A measurement may for example be made as explained in patent DE 39 37 966 or as discussed in U.S. Pat. No. 5,864,056 or in U.S. Pat. No. 5,502,433.
On the basis of the forces measured by one or other of the above methods, and from equilibrium equations of a ground contacting arrangement, the forces acting at the center of each wheel may accordingly easily be calculated. Thus, in real time 3 forces X, Y and Z are available, which in particular enables the Y or Z signal to be processed for the reasons explained in the present document.
The invention also relates to vehicle stability control systems, said vehicle having a body and at least one front ground contacting arrangement and at least one rear ground contacting arrangement, each ground contacting arrangement comprising in each case one wheel, each wheel comprising a pneumatic or non-pneumatic tire in contact with the ground, the vehicle having a characteristic time that is a function of its inertia and corresponds to the time phase shift in the manifestation of the cornering forces on the wheels in the front and in the rear, following a command from the driver of the vehicle, the vehicle being provided with operating means to act on the forces transmitted to the ground by each of the wheels, such as brakes, means for steering the wheels. The system further comprises:
(a) means for measuring in real time the actual values of one variable selected in the group of the cornering force “Y” and the vertical load “Z” acting at the center of each of the front and rear wheels; (b) a controller allowing to calculate in real time the desired values of at least one reference parameter, said at least one reference parameter being correlatable to the actual values, as a result of an action of the driver on the operating means and taking into account the load transfers on both sides of the mid plane of symmetry of the vehicle, said controller allowing to perform comparisons between the desired values with the measured actual values in order to obtain an error signal, and; (c) means for acting on the operating means so as to minimize the error signal.
According to various aspects, as explained hereabove for the method for controlling the stability of a vehicle, the variable can be the actual cornering force “Y” in which case the reference parameter can be either the desired cornering force “Y d ” or the desired yaw moment “M d ”, or said variable is the vertical load “Z” and the reference parameter is the desired loads “Z d ”.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in more detail hereinafter with the aid of the accompanying figures, in which:
FIG. 1 is a block diagram illustrating a system in accordance with the invention,
FIG. 1A shows schematically a car featuring the system according to the invention,
FIG. 2 shows the arrangement of a two-wheeled vehicle and frame of reference,
FIG. 3 a shows the arrangement of a four-wheeled vehicle and frame of reference;
FIG. 3 b is a side view of a four-wheeled vehicle of FIG. 3 a;
FIG. 3 c is a front view of a four-wheeled vehicle of FIG. 3 a;
FIG. 4 shows the linearized cornering stiffness curve;
FIGS. 5 a-c, 6 a-d, and 7 a-d illustrate the forces resulting from a steering command in the form of an increasing sinusoidal curve, on a wet surface at 90 km/hour, in which,
FIG. 5 a illustrates the front axle cornering force,
FIG. 5 b illustrates the rear axle cornering force,
FIG. 5 c illustrates the yaw moment,
FIG. 6 a illustrates the left front load,
FIG. 6 b illustrates the right front load,
FIG. 6 c illustrates the left rear load,
FIG. 6 d illustrates the right rear load,
FIG. 7 a illustrates the left front cornering force,
FIG. 7 b illustrates the right front cornering force,
FIG. 7 c illustrates the left rear cornering force, and
FIG. 7 d illustrates the right rear cornering force;
FIGS. 8 a-c, 9 a-d, and 10 a-d illustrate the forces resulting from a steering command in the form of a increasing sinusoidal curve, on a wet surface at 90 km/hour for a vehicle equipped with means for controlling the anti-rolling distribution, in which,
FIG. 8 a illustrates the front axle cornering force,
FIG. 8 b illustrates the rear axle cornering force,
FIG. 8 c illustrates the yaw moment,
FIG. 9 a illustrates the left front load,
FIG. 9 b illustrates the right front load,
FIG. 9 c illustrates the left rear load,
FIG. 9 d illustrates the right rear load,
FIG. 10 a illustrates the left front cornering force,
FIG. 10 b illustrates the right front cornering force,
FIG. 10 c illustrates the left rear cornering force, and
FIG. 10 d illustrates the right rear cornering force;
FIG. 11 illustrates the differences of path between a vehicle with control (reference numeral 2 ) of the anti-rolling distribution and a vehicle without control of the anti-rolling distribution (reference numeral 1 ) in a maneuver involving a steering command in the form of an increasing sinusoidal curve, on a wet surface at 90 km/hour,
FIG. 12 illustrates the anti-rolling distribution in order to stabilize the vehicle;
FIGS. 13 a-c, 14 a-d, and 15 a-d illustrate the forces resulting from an avoidance maneuver, on a wet surface, at 90 km/hour, leading to a destabilization of the vehicle, in which,
FIG. 13 a illustrates the front axle cornering force,
FIG. 13 b illustrates the rear axle cornering force,
FIG. 13 c illustrates the yaw moment,
FIG. 14 a illustrates the left front load,
FIG. 14 b illustrates the right front load,
FIG. 14 c illustrates the left rear load,
FIG. 14 d illustrates the right rear load,
FIG. 15 a illustrates the left front cornering force,
FIG. 15 b illustrates the right front cornering force,
FIG. 15 c illustrates the left rear cornering force, and
FIG. 15 d illustrates the right rear cornering force;
FIGS. 16 a-c, 17 a-d, and 18 a-d illustrate the forces resulting from an avoidance maneuver, on a wet surface, at 90 km/hour, for a vehicle equipped with a control of the anti-rolling distribution, in which
FIG. 16 a illustrates the front axle cornering force,
FIG. 16 b illustrates the rear axle cornering force,
FIG. 16 c illustrates the yaw moment,
FIG. 17 a illustrates the left front load,
FIG. 17 b illustrates the right front load,
FIG. 17 c illustrates the left rear load,
FIG. 17 d illustrates the right rear load,
FIG. 18 a illustrates the left front cornering force,
FIG. 18 b illustrates the right front cornering force,
FIG. 18 c illustrates the left rear cornering force, and
FIG. 18 d illustrates the right rear cornering force;
FIG. 19 illustrates the path differences between a vehicle with control (reference numeral 2 ) of the anti-rolling distribution and a vehicle without control of the anti-rolling distribution (reference numeral 1 ), in this avoidance maneuver, on a wet surface, at 90 km/hour;
FIG. 20 illustrates the anti-rolling distribution in order to stabilize the vehicle.
DETAILED DESCRIPTION
We shall start from the fact that, at a given velocity, an angle at the steering wheel imposed by the driver may be interpreted as a cornering force or load instruction, or as a yaw moment instruction on the vehicle. This is shown diagrammatically in the upper part of FIG. 1 . Furthermore, it has been seen that in order to implement the present invention, it is necessary to have measurements of the actual cornering forces (cornering forces of the tires or elastic tire casings used in the ground contacting arrangement). This is illustrated in the left-hand section, starting from “vehicle,” in FIG. 1 . In the case where it is desired to act on the distribution of the loads (see other explanations below concerning the effect on the yaw moment of the distribution of the loads), it is necessary to have measurements of the actual loads.
The diagram in FIG. 1 superimposes several methods: either the actions of the driver at a given moment and the preceding actions are interpreted as a demand for cornering forces, which are compared to the cornering forces measured at the center of the wheel, or the actions of the driver and the preceding actions are interpreted as a demand for changes in load, which are compared to the loads measured at the center of the wheel, or alternatively, the actions of the driver are interpreted as a demand for a yaw moment, and the cornering force measurements made at the center of the wheel are converted into a measured yaw moment in order to make the required comparison. The differences found by a comparator enable a controller to decide on the necessary correction by acting on the operating means so as to stabilize the vehicle and make it follow the instructions of the driver.
In a vehicle, the steering of the wheels results in a cornering force of the front axle, a movement of the vehicle body, followed by a cornering force of the rear axle. The cornering force of the rear axle thus occurs with a slight delay with respect to the command on the steering wheel. In order to be able to determine the path correction actions more accurately, the invention proposes to take account of this delay.
The instruction values of the cornering forces then depend on the action on the steering command at the present instant t and at the instant t minus the delay associated with the inertia of the vehicle (termed T). This delay time depends only on the characteristics of the vehicle (inertia, wheelbase) and the sideslip rigidities of its pneumatic suspension. An expression for this delay time is:
T = I Vehicle V l 1 2 D F + l 2 2 D R
where
V is the instantaneous velocity of the vehicle; I vehicle is the inertia of the vehicle undergoing yaw (also referred to as Iz); L 1 is the distance from the front axle to the center of gravity; L 2 is the distance from the rear axle to the center of gravity; and, D F , D R are the sideslip rigidities of the front and rear axles (sum of the sideslip derivatives of the tires of the same axle).
It is assumed that the cornering forces of the front train are less than the forces required by the driver (as determined by his actions on the commands). An automatic action enables a resultant force on the vehicle chassis to be obtained in accordance with the wishes of the driver and thus enables understeering to be avoided.
The various operating means that may be actuated include, of course, the brakes. As an alternative or in addition to a braking action, an action on a supplementary steering means, exerted for example by means of an irreversible stepping motor mounted in the steering column, also enables the resultant forces on the vehicle chassis to be approximated in accordance with the wishes of the driver. Another possible way of effecting the action on a steering means consists for example in sending the appropriate control commands to the controller described in U.S. Pat. No. 5,884,724.
As an alternative or as a further addition to braking actions or actions on the steering mentioned above, an action on the distribution of the anti-roll device between the front axle and rear axle also enables action to be exerted on the cornering forces developed respectively by the front and rear axles. This involves altering the load supported by each wheel by modifying the distribution of the overall load (unchanged) between the wheels, fully taking account of the load transfer to the outer wheels when steering or cornering.
In fact, when a vehicle departs from the path desired by the driver, one or other or several of the tires become incapable of developing the excess cornering force that they would have had to develop in order to compensate for the forces of inertia. It may be said that the tire or tires have reached their saturation limit. More specifically, this saturation phenomenon, when it starts, involves for most of the time a single tire of a single axle. As a result one of the axles becomes incapable of developing the expected cornering force and the vehicle will oversteer or understeer depending on whether the saturation involves the rear axle or the front axle.
Furthermore, it is known that when steering, the centrifugal force overloads the outer tires. The distribution of this overload between the front axle and rear axle depends on the anti-roll characteristics of the vehicle suspension.
By reducing the share of anti-rolling force developed by the axle containing the tire whose cornering force reaches saturation point first, not only can the other tire on the same axle develop a greater cornering force due to a larger vertical load, but also the saturation point of a tire on the other axle will be approached or even reached, thereby setting a limit on or reducing the cornering forces developed by the other axle.
If on the other hand it is the cornering force of the rear axle that reaches saturation point first, the vehicle oversteers because the cornering force forces of the rear train are less than the forces desired by the driver. An automatic braking action or action on a supplementary steering means or on the anti-roll distribution enables a resultant forces to be obtained on the vehicle chassis in accordance with the wishes of the driver and thus enables oversteering to be avoided.
FIG. 2 shows a representation of a two-wheeled vehicle according to a commonly adopted simplification employed also for modeling four-wheeled vehicles. The center of gravity of the vehicle is denoted by CG, the longitudinal axis of the vehicle connecting the front wheel (turned) and the rear wheel and passing through the center of gravity (axis CGx). The sum of the cornering forces Y F , Y R acting on the wheels of each axle in question is translated to the center of each axle. The angle δ that the velocity vector makes with respect to the longitudinal axis of the vehicle, and the yaw rate ψ of the vehicle around the vertical axis of the vehicle are shown. The distance between the front axle (and respectively the rear axle) and the center of gravity CG is denoted by l 1 (respectively l 2 ). Such a diagram already enables interesting results to be obtained.
However the invention proposes, in order to determine more accurately the correction actions on the path, to take account of the forces on the ground wheel by wheel. In the center of an axle a comparison of the cornering forces of each wheel and the desired cornering forces enables the cause of saturation of the overall arrangement of the axle to be determined exactly and thus enables more effective correction actions to be selected.
FIG. 3 a shows diagrammatically a four-wheeled vehicle, with a center of gravity CG. Neither the angle δ that the velocity vector makes with respect to the longitudinal axis of the vehicle, nor the yaw angle ψ are shown, so as not to complicate the diagram. The four-wheeled model is closer to the vehicle in the sense that it takes into account the forces on the centers of the four wheels and expresses the lateral load transfers associated with the engagement of the anti-roll device of the vehicle when steering. The four-wheeled model is accordingly more complete than the two-wheeled model and more accurately reflects the action of the load transfers on the dynamics of the vehicle. The loads on each of the four tires are represented by Zp 1 , Zp 2 , Zp 3 and Zp 4 . The cornering forces (or lateral forces) acting on each of the wheels are identified by the reference numerals Yp 1 , Yp 2 , Yp 3 and Yp 4 .
FIG. 3 b shows the rolling axis R of the vehicle, the height h of the center of gravity CG with respect to the ground, the height h 1 of the rolling axis R with respect to the ground in the vertical plane passing through the center of the areas of contact of the tires of the front axle with the ground, and the height h 2 of the rolling axis with respect to the ground in the vertical plane passing through the center of the areas of contact of the tires of the rear axle with the ground. The four-wheeled model is based on the assumption of a sprung mass MS resting on 2 axles. This sprung mass is able to rotate about the rolling axis R.
FIG. 3 c shows the oversteering moment of the vehicle caused by the load transfer in the transverse direction, K 1 and K 2 representing the anti-rolling rigidities on respectively the front axle and the rear axle. In the diagram “v 1 ” denotes the front track of the vehicle and “v 2 ” denotes the rear track of the vehicle.
The monitoring of the four supports and error signals generated between the desired cornering forces and actual cornering forces enables the four supports to be optimized by acting in an appropriate manner on the operating means, as will be explained hereinafter.
The procedure for controlling the operating means described above are shown diagrammatically in the “Controller” box in FIG. 1 , which controls the one or more “operating means” discussed above.
The above paragraphs refer to what is commonly known as the stationary state (or the steady state). Considering a typical transient state of an emergency maneuver (avoiding an obstacle, changing lane), the speed of actuation of the steering wheel is instead regarded as equivalent to a desired yaw moment on the vehicle. If the actual yaw moment is less than the desired yaw moment, the vehicle does not turn sufficiently. If the actual yaw moment is greater than the desired yaw moment, the vehicle turns excessively. The controller then acts in an appropriate manner on one or other or several of the possible operating means including the brakes, or on a supplementary steering means or on the distribution of the anti-rolling system, thereby enabling a yaw moment to be exerted on the vehicle chassis in accordance with the wishes of the driver.
The following conventional expressions will be adopted:
Desired front axle cornering force: Y F d Desired rear axle cornering force: Y R d Desired cornering force of the tires: Yp 1,2,3,4 d Desired load on each tire: Zp 1,2,3,4 d Desired yaw moment: M z d ψ yaw angle of the vehicle δ sideslip angle of the vehicle α c steering angle of a wheel γt transverse acceleration D 1,2,3,4 the sideslip rigidities of the tires D F and D R the sideslip rigidities of the front and rear axles
A two-wheeled vehicle will first of all be discussed hereinafter (see FIG. 2 ).
The equations of the two-wheeled vehicle are as following:
Mγ t =MV ({dot over (δ)}+{dot over (ψ)})= Y F +Y R (1)
where M is the mass of the vehicle, V is the longitudinal velocity of the vehicle, Y F is the cornering force on the front axle, and Y R is the cornering force on the rear axle, equation (1) expressing the fact that the cornering forces balance out the transverse acceleration,
I z {umlaut over (ψ)}=l 1 Y F −l 2 Y R (2)
where I z is the yaw inertia, l 1 is the distance from the front axle to the center of gravity, l 2 is the distance from the rear axle to the center of gravity, equation (2) expressing the fact that the moments are in equilibrium.
The rigid body movement of the two-wheeled vehicle and the steering of the wheels of the front axle enables the sideslips of the front and rear tires to be expressed as follows:
Sideslip of the front train:: δ F = δ + l 1 ψ . V - α C ( 3 ) Sideslip of the rear train: δ Arr = δ - l 2 ψ . V ( 4 )
The quantity l 1 (respectively l 2 ) is the distance from the front axle (respectively rear axle) to the center of gravity CG of the vehicle. The geometry of the vehicle is shown in FIG. 2 .
These sideslips of the tires give rise to cornering forces on the two-wheeled vehicle:
Y F =−D F δ F (5)
Y R =−D R δ R (6)
By substituting the equations 3 and 4 in 5 and 6, one obtains
Y F = - D F ( δ + l 1 ψ . V - α C ) ( 7 ) Y R = - D R ( δ - l 2 ψ . V ) ( 8 )
By substituting the equations (7) and (8) in the equations (1) and (2), a system is obtained that is expressed only as a function of the yaw rate (and its derivative), the sideslip angle (and its derivative), and the characteristics of the vehicle:
MV ( δ . + ψ . ) = D F ( δ + l 1 ψ . V - α c ) + D R ( δ - l 2 ψ . V ) ( 1 bis ) I z ψ ¨ = l 1 ( D F ( δ + l 1 ψ . V - α c ) ) - l 2 ( D R ( δ - l 2 ψ . V ) ) ( 2 bis )
By a Laplace transform it is possible to express the transfer functions between the yaw rate and the angle at the steering wheel, and between the body sideslip and the angle at the steering wheel. The static part (that is to say the part relating to a zero frequency) of this transfer function is then simply expressed as a function of the characteristics of the vehicle (coefficient of proportionality) and of the forward movement velocity:
ψ . = 1 l 1 + l 2 V 1 + V 2 D F D R ( l 1 + l 2 ) 2 M ( D R l 2 - D F l 1 ) α c ( 9 ) δ = 1 l 1 + l 2 l 2 - l 1 MV 2 D R ( l 1 + l 2 ) 1 + V 2 D F D R ( l 1 + l 2 ) 2 M ( D R l 2 - D F l 1 ) α c ( 10 )
These expressions may be simplified by introducing a quantity Vc, called critical velocity, which is comparable to a velocity and depends on the characteristics of the vehicle (weight supported by the front axle M F , weight supported by the rear axle M R , distances l 1 and l 2 ) and its pneumatic mounting:
V c 2 = D F D R ( l 1 + l 2 ) 2 M ( D R l 2 - D F l 1 ) = D F D R ( l 1 + l 2 ) D R M F - D F M R = l 1 + l 2 M F D F - M R D R ( 11 )
The expressions (9) and (10) become:
ψ . = 1 l 1 + l 2 V 1 + V 2 V c 2 α c
δ = 1 l 1 + l 2 l 2 - l 1 MV 2 D R ( l 1 + l 2 ) 1 + V 2 V c 2 α c
These expressions may be reintroduced into the equations (3) and (4) and then into the equations (5) and (6) in order to obtain the forces desired by the driver:
Y F desired = M F l 1 + l 2 V 2 1 + V 2 Vc 2 α c ( 12 ) Y R desired = M R l 1 + l 2 V 2 1 + V 2 Vc 2 α c ( 13 )
It can be seen that these formulae express the fact that the cornering force demand resulting from the actions of the driver depends only on the command (α c ) itself, on the velocity of the vehicle (V) and on other parameters, all of which are functions of the vehicle itself (that is to say describe the vehicle).
Finally, by differentiating equation (9) and multiplying the yaw acceleration by the yaw inertia, one obtains the desired yaw moment Mz:
ψ ¨ = 1 l 1 + l 2 V 1 + V 2 Vc 2 α . c M Z desired = I Z ψ ¨ = I z l 1 + l 2 V 1 + V 2 Vc 2 α . c ( 14 )
Similarly, formula (14) expresses the fact that the yaw moment demand resulting from the actions of the driver depends only on the command (α c ) itself, on the velocity of the vehicle (V) and on other parameters, all of which are functions of the vehicle itself (that is to say describe the vehicle).
It is also possible to express the changes of commands at the steering wheel as demands for changes of forces in the trains:
Y . F desired = M F l 1 + l 2 V 2 1 + V 2 Vc 2 α . c ( 15 ) Y . R desired = M R l 1 + l 2 V 2 1 + V 2 Vc 2 α . c ( 16 ) Y R desired ( t ) = M R 1 + V 2 V c 2 V 2 l 1 + l 2 α c ( t - T )
Y . R desired ( t ) = M R l 1 + l 2 V 2 1 + V 2 Vc 2 α . c ( t - T ) ( 17 )
The instruction at the instant t depends on the steering command at the instant t−T. This delay, which is associated with the yaw inertia of the vehicle, appears as a characteristic time of the vehicle in equation (2 bis). /
I z ψ ¨ = l 1 ( D F ( δ + l 1 ψ . V - α c ) ) - l 2 ( D R ( δ - l 2 ψ . V ) )
I z ψ ¨ - l 1 2 D F + l 2 2 D R V ψ . = ( l 1 D F - l 2 D R ) δ - l 1 D R α c
The yaw time constant is thus:
T = I Z V l 1 2 D F + l 2 2 D R ( 18 )
It is assumed that it is possible to measure at each instant the cornering forces Y for all the wheels, the variations of the cornering forces Y, and the variations of angle at the steering wheel. It is proposed to actuate a path control system as soon as the difference between the desired forces and the actual measured forces becomes too large. The criterion of stability that is thus proposed expresses the fact that the vehicle remains stable as long as this difference is small (compromise between the wishes of the driver and the actual conditions).
This criterion of stability takes into account the fact that the cornering force of the tire reaches saturation point either because the tire is no longer in a straight line with the sideslip, or because the tire is no longer in a straight line with the applied load. In order to be able to detect this double saturation more readily, it is assumed that the tire is in a straight line with respect to both the load and the sideslip. This linearization is illustrated in FIG. 4 . The continuous line represents a real curve giving the value of the cornering stiffness of a tire as a function of the load applied to the tire, and the dotted line, plotted according to the linearization assumption, gives the value of the cornering stiffness of a tire as a function of the load applied to the tire. It can be seen that the difference with respect to reality increases as the saturation point (load saturation) of the tire is approached. Furthermore, the linear model representing the cornering stiffness of the tire with respect to the load should give results comparable to the actual state of affairs close to the operational point so as not to trigger a system under normal driving conditions (see meeting point of the continuous curve and dotted line curve). The proposed solution consists in modeling a theoretical tire that would have a linear cornering stiffness (dotted straight line curve), forming a tangent to a real cornering stiffness curve at the static operating point M F g/2, that is to say without transfer of load.
By linearizing the expression for the cornering stiffness of a tire on the front axle, we obtain:
D 1 ( Zp 1 ) = D 1 , 0 + ( ∂ D 1 ∂ Z ) 0 ( Zp 1 - M F g 2 ) ( 19 )
∂ D ∂ Z
is the sensitivity of the cornering stiffness to the transfer of load in the vicinity of the static load M F g/2. This sensitivity at the front is denoted A 1 and at the rear is denoted A 2 . D 1,0 is the cornering stiffness of the front tire under a static load M F g/2
The cornering stiffness of a front tire thus takes the form:
D 1 ( Zp 1 ) = D 1 , 0 + A 1 * ( Zp 1 - M F g 2 ) ( 19 bis )
The cornering stiffness of a rear tire thus takes the form:
D 3 ( Zp 3 ) = D 3 , 0 + A 2 * ( Zp 3 - M R g 2 )
Similarly, the suspension is modeled by linear relationships giving load transfers under a permanent regime. The following notations are adopted to describe the suspensions:
Ms sprung weight of the vehicle; K 1 rigidity of the front anti-rolling bar; K 2 rigidity of the rear anti-rolling bar; h 1 height of the front axle rolling center; h 2 height of the rear axle rolling center; h height of the center of gravity; V 1 track of the front train; and, V 2 track of the rear train.
These notations are illustrated in FIGS. 3 a, 3 b, 3 c.
By means of the expressions for the desired cornering forces, and using the linear suspension model, the discounted load transfer on axle 1 is:
Δ Z F desired = 1 v 1 [ K 1 h K 1 + K 2 - M S gh + M F M S h 1 ] M S 1 + V 2 V c 2 V 2 l 1 + l 2 α c ( 20 )
Furthermore, the vehicle body movements are delayed with respect to the steering wheel steering, with a delay time given by expression (18).
Δ Z F desired ( t ) = 1 v 1 [ K 1 h K 1 + K 2 - M S gh + M F M S h 1 ] M S 1 + V 2 V c 2 V 2 l 1 + l 2 α c ( t - T ) ( 20 bis )
On the tires of the front train the instruction load is thus the sum of the static load on a quarter of the vehicle and the load transfer on the axle.
Zp 1 desired = M F g 2 + Δ Z Av desired
Zp 2 desired = M F g 2 - Δ Z F desired
On the front train the expected vertical loads are:
Zp 1 desired ( t ) = M F g 2 + 1 v 1 [ K 1 h K 1 + K 2 - M S gh + M F M S h 1 ] M S 1 + V 2 V c 2 V 2 l 1 + l 2 α c ( t - T ) ( 21 ) Zp 2 desired ( t ) = M F g 2 - 1 v 1 [ K 1 h K 1 + K 2 - M S gh + M F M S h 1 ] M S 1 + V 2 V c 2 V 2 l 1 + l 2 α c ( t - T ) ( 21 bis )
On the rear train the expected vertical loads are:
Zp 3 desired ( t ) = M R g 2 + 1 v 2 [ K 2 h K 1 + K 2 - M S gh + M R M S h 2 ] M S 1 + V 2 V c 2 V 2 l 1 + l 2 α c ( t - T )
( 22 ) Zp 4 desired ( t ) = M R g 2 - 1 v 2 [ K 2 h K 1 + K 2 - M S gh + M R M S h 2 ] M S 1 + V 2 V c 2 V 2 l 1 + l 2 α c ( t - T ) ( 22 bis )
Knowing the load on each tire, by linear modeling of the tire (equation 19 bis) the instruction cornering force on each of the four tires can be deduced:
Yp 1 desired=− D 1 ( Zp 1 desired)*δ F desired
From equations (3), (4), (9) and (10) the desired tire sideslips are:
δ R desired ( t ) = - M R D R 1 + V 2 V c 2 V 2 l 1 + l 2 α c ( t )
( 23 ) δ R desired ( t ) = - M R D R 1 + V 2 V c 2 V 2 l 1 + l 2 α c ( t - T ) ( 24 )
By using the expressions for the cornering stiffness (19 bis), the desired load (21) and the desired tire sideslip (23), the instruction cornering force is then:
Yp 1 desired ( t ) = D 1 , 0 + A 1 ( Zp 1 desired ( t ) - M R g 2 ) D R M F 1 + V 2 V c 2 V 2 l 1 + l 2 α c ( t ) ( 25 ) Yp 2 desired ( t ) = D 2 , 0 + A 1 ( Zp 2 desired ( t ) - M F g 2 ) D R M F 1 + V 2 V c 2 V 2 l 1 + l 2 α c ( t ) ( 25 bis )
Similarly, on the rear axle and taking into account the delay in the cornering force of the rear axle, we have:
Yp 3 desired ( t ) = D 3 , 0 + A 2 ( Zp 3 desired ( t ) - M R g 2 ) D R M R 1 + V 2 V c 2 V 2 l 1 + l 2 α c ( t - T ) ( 26 ) Yp 4 desired ( t ) = D 4 , 0 + A 2 ( Zp 4 desired ( t ) - M R g 2 ) D R M R 1 + V 2 V c 2 V 2 l 1 + l 2 α c ( t - T ) ( 26 bis )
It is assumed that the cornering forces Y for all the wheels, the variations of the cornering forces Y, and the variations of the angle at the steering wheel can be measured at each instant in time. It is proposed that a path control system be triggered as soon as the difference between the desired forces and the actual measured forces becomes too large. The criterion of stability that is thus proposed expresses the fact that the vehicle remains stable as long as this difference remains small (compromise between the wishes of the driver and the actual conditions).
The advantage of detecting these differences on each wheel is that the system knows more precisely the reason for the loss of control of the vehicle.
A simulation of the dynamic behavior of a vehicle under typical maneuvers is presented with the aid of the following figures. The simulation model that is used is a four-wheeled model with 7 degrees of freedom, enabling the equilibrium of the vehicle to be expressed in terms of yaw, pitch, roll and rotation of the four wheels. The four simulations presented here relate to a vehicle whose characteristics are those of a Volkswagen Golf car travelling at a speed of 90 km/h.
In the first simulation ( FIGS. 5 a-c, 6 a-d, and 7 a-d ), a sinusoidal pulse of frequency 0.5 Hz of increasing amplitude and on a wet surface is plotted as a steering wheel instruction. This maneuver leads to the loss of control of the vehicle. In all the figures illustrating tire cornering forces (Yp), the axle cornering forces (Y F , Y R ), the loads (Zp) or yaw moments (Mz) the continuous curves, denoted by “A”, represent the actual values, while the dotted curves, denoted by “D”, represent the values desired by the driver.
In FIGS. 5 a, 5 b, and 5 c the plotted curves show the difference between the sum of the two cornering forces of a train (front train or rear train according to the indices “F” or “R” of the figures) and the force desired by the driver, in the context of formulae (12), (13) and (14). The saturation of the forces of the tire with respect to the driver's expectations and the phase difference between the actual forces and the expected forces can be noted.
In FIGS. 6 a , 6 b , 6 c , and 6 d the differences between the actual loads and the loads desired by the driver as expressed by the formulae (21), (21 bis), (22) and (22 bis) can be seen. In FIGS. 7 a, 7 b, 7 c and 7 d this loss of control is detected via the saturation of the observed cornering forces of the tires as the difference between the instruction cornering forces expressed by the formulae (25), (25 bis), (26) and (26 bis) and the actual cornering forces. At the same time it is found that the actual forces are delayed with respect to the instruction, illustrating the phase difference between the intervention of the driver and the reactions of the vehicle. In each case the reference “A” represents the actual forces (continuous line) and the reference “D” refers to the instruction expressed by the proposed method (dotted line).
In the second simulation ( FIGS. 8 a-c, 9 a-d, 10 a-d, 11 and 12 ) it is shown how a modification of the front/rear anti-rolling distribution, controlled as explained above, enables the path of the vehicle to be stabilized. The maneuver is identical to the previous maneuver (steering command in the form of an increasing sinusoidal curve on a wet surface at 90 km/h). As soon as excessive yaw forces are detected, the anti-rolling device is reinforced at the front of the vehicle and is reduced by the same amount at the rear so as to make the vehicle stable as quickly as possible and to utilize in the best possible way the gripping potential of the four tires. The saturation of the cornering forces is better controlled and permits smaller phase differences, which means that yaw moments are better handled and vehicle body changes are more readily identified. To reiterate, in each case the reference “A” represents the actual forces (continuous curve) and the reference “D” refers to the instruction expressed by the proposed method (dotted curve).
FIGS. 8 a , 8 b , and 8 c show the actual and desired cornering forces of the front axle, the rear axle, and the yaw moment of the vehicle. FIGS. 9 a , 9 b , 9 c , and 9 d show the actual and desired vertical loads Zp on the four tires. FIGS. 10 a , 10 b , 10 c , and 10 d show the actual and desired lateral cornering forces Yp on the four tires.
Although the anti-rolling dynamic distribution does not enable the saturation of the tire to be avoided completely under the existing gripping conditions, it nevertheless enables the error signal to be minimized and the delay between the commands of the driver and the responses of the vehicle to be reduced ( FIGS. 9 a-d, 10 a-d ).
FIG. 11 symbolizes the vehicle (represented by a rectangle) on the aforedescribed path by its center of gravity (shown as a continuous line). In this representation the alignment of the vehicle is shown via the angle that the vehicle makes with the path. The phase difference between the actual alignment of the vehicle and the desired path may be observed by recording, in specific successive positions illustrated in FIG. 11 , the more or less large angle between the orientation of the vehicle and the tangent to the path at the center of gravity of the vehicle until loss of control of the vehicle supervenes due to oversteering.
This loss of control may be anticipated by the difference between the desired yaw moment and the actual yaw moment. The actual yaw moment is much too large and causes the vehicle to swerve, as is shown by the path (FIG. 11 ). By making the driver's instructions responsive to the forces, such as described by the proposed method, the vehicle remains stable and follows the path desired by the driver (reference numeral 2 , FIG. 11 ).
FIG. 12 illustrates the anti-rolling distribution in order to stabilize the vehicle. If a saturation is observed, an anti-roll force is exerted on the rear axle in order to increase the front anti-roll while maintaining constant the overall anti-roll stiffness. This change in distribution of the loads stabilizes the vehicle by causing it to understeer more.
In the third simulation ( FIGS. 13 a-c, 14 a-d, and 15 a-d ), the driver changes lane on a wet road surface and loses control of the vehicle. In each case the reference “A” represents the actual forces (continuous line) and the reference “D” refers to the instruction expressed by the proposed method (dotted line). FIGS. 13 a-c show the actual and desired cornering forces of the front axle, rear axle, and the yaw moment of the vehicle.
In FIGS. 13 a-c it can be seen that the saturation of the cornering forces of the front and rear axles and the cornering force delay of the rear axle lead to loss of control of the vehicle and to swerving. This swerving is also illustrated via the overload in the yaw moment with respect to the yaw moment desired by the driver. The loss of control of the vehicle may be detected wheel by wheel by measuring the difference between the instruction cornering forces (described by the formulae (25), (25 bis), (26) and (26 bis)) and the actual cornering forces or the difference between the instruction loads (described by the formulae (21), (21 bis), (22) and (22 bis)) and the actual loads. FIGS. 14 a , 14 b , 14 c , and 14 d show the actual and desired vertical loads Zp on the four tires. FIGS. 15 a , 15 b , 15 c , and 15 d represent the actual and desired lateral cornering forces Yp on the four tires.
The fourth simulation ( FIGS. 16 a-c, 17 a-d, 18 a-d, 19 and 20 ) shows how a modification of the front/rear anti-rolling distribution, controlled as explained hereinbefore, enables the path of the vehicle to be stabilized. In each case the reference “A” represents the actual forces (continuous line) and the reference “D” refers to the instruction expressed by the proposed method (dotted line). The maneuver is identical to the preceding maneuver (avoidance maneuver on a wet surface at 90 km/hour). As soon as excessive yaw forces are detected the anti-roll device is reinforced at the front of the vehicle and decreased by the same amount at the rear of the vehicle so as to stabilize the vehicle as quickly as possible and to utilize in the best possible way the gripping potential of the four tires. The saturation of the cornering forces is handled more effectively and permits smaller phase differences, which means that yaw moments are better controlled and movements of the vehicle body are more easily identified. By means of the anti-roll dynamic distribution the system reduces the delay between the driver's instructions to exert the necessary forces and the reaction of the vehicle, and avoids the swerving that is observed in the absence of the system. FIGS. 16 a , 16 b, and 16 c show the actual and desired cornering forces of the front axle, rear axle, and the yaw moment of the vehicle. FIGS. 17 a, 17 b, 17 c, and 17 d show the actual and desired vertical loads Zp on the four tires. FIGS. 18 a , 18 b, 18 c, and 18 d show the actual and desired lateral cornering forces Yp on the four tires.
The swerving observed when the vehicle is out of control ( FIG. 19 , reference numeral 1 ) is restricted in the presence of the anti-roll control device ( FIG. 19 , reference numeral 2 ), which is reflected in an alignment of the vehicle parallel to the path of the center of gravity (continuous line).
FIG. 20 illustrates the anti-rolling distribution in order to stabilize the vehicle. If a saturation is observed, an anti-roll force is exerted on the rear axle in order to increase the front anti-roll while maintaining constant the overall anti-roll stiffness. This change in distribution of the loads stabilizes the vehicle by causing it to understeer more. | The invention proposes a method for regulating a stability control system of a vehicle based on the forces acting at the center of each wheel of the vehicle. The actions of the driver, i.e. steering, acceleration or braking, produce forces (changes in forces) are transmitted by the tires to the ground. Control of the operating means of the vehicle (active anti-roll device, engine torque, braking torque, load per wheel or direction) utilizes instructions resulting from the actions of the driver to apply forces. The invention proposes a method of expressing, in terms of forces, the inputs of the driver as a function of the inertia of the vehicle body, velocity of forward movement of the vehicle, and angle at the steering wheel (steering wheel velocity and steering wheel acceleration). If the actual forces that are measured do not correspond to the forces desired by the driver, the active system compensates for this difference by acting on the force distributions in the chassis. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is the U.S. National Phase application of PCT International Application No. PCT/FR2012/051998, filed Sep. 6, 2012, and claims priority to French Patent Application No. 1158871, filed Sep. 30, 2011, the disclosures of which are incorporated by reference in their entirety for all purposes.
FIELD OF THE INVENTION
The present invention relates to a process for producing mechanical paper pulp. It also relates to a composition employed in this method, and to the use of this composition in a method for producing mechanical paper pulp. It relates, lastly, to a papermaking process.
BACKGROUND OF THE INVENTION
Paper pulps called “mechanical pulps” or “high-yield pulps” or “wood pulps” are obtained directly from wood by a sequence of mechanical treatments, generally referred to collectively as mechanical “refining”, and carried out by means of grindstones and/or refiners. The mechanical paper pulp is subsequently subjected to a bleaching phase, which may comprise one or more stages, depending on the degree of whiteness required.
The advantage of a mechanical pulp production process is its high material yield as compared with a “chemical” pulp production method. The reason is that, unlike the chemical pulp production methods, in which the lignin present in the untreated wood is removed almost entirely by cooking in the presence of chemical products, around 90% of the untreated wood is conserved in the pulps obtained at the outcome of a mechanical pulp production method.
The mechanical refining in a mechanical pulp production method typically comprises a number of refining steps, such as a primary refining operation, generally called “defibering”, a secondary refining operation, a tertiary refining operation, an operation of refining screening wastes, etc. These refining steps provide pulps which have different degrees of refining, in order to progressively transform the wood into individualized fibers and so to allow the production of paper pulp.
Mechanical refining has the drawback of being highly energy-consuming, consuming typically from 1500 to 3000 kWh per metric ton of mechanical pulp produced. This energy on the one hand represents a substantial cost and on the other hand may cause damage to the wood fibers. Various pathways have therefore been conceived in order to reduce the required energy.
Accordingly, document EP 1728917 proposes carrying out a refining operation at low consistency, in other words at low pulp dry matter content. A treatment of this kind, however, requires a host of apparatus, and is of limited efficacy.
Document WO 08081078, in turn, proposes a mechanical pulp production method comprising a step of ozone treatment during refining. This treatment, however, has the drawback of giving rise to chromophoric groups on the polysaccharide molecules contained in the wood, these groups proving difficult to oxidize when the pulp is subsequently bleached conventionally.
Moreover, a particular interest has developed in enzymatic wood treatments within mechanical pulp production methods, owing to their gentle environmental impact.
Known accordingly is document U.S. Pat. No. 6,267,841, which describes a mechanical pulp production method comprising an enzymatic treatment step performed between two refining steps or prior to one refining step. The enzyme is selected from pectinases, xylanases, laccases, cellulases, manganese peroxidases, and mixtures thereof. These treatments, however, have the drawback of degrading the wood fibers, and/or require refining to be carried out at a high temperature, thereby limiting the energy saving that is realizable.
Documents EP 429422 and WO 91/11552 also describe mechanical pulp production methods which comprise a step of enzymatic pretreatment of a fibrous material for the purpose of facilitating its subsequent refining. In document EP 429422, the redox potential of the enzymes described is adjusted using regulators such as gaseous oxygen or nitrogen, antioxidants, sugars, organic acids, or inorganic salts. In document WO 91/11552, a recommendation is made to carry out the enzymatic pretreatment beyond a certain redox potential. Adjusting the redox potential of the enzymes, however, is a delicate operation, and proves to be costly.
Document EP 0745 154 describes a chemical pulp production method employing a multiple-component system for the modification, decomposition, or decoloring of the lignin, comprising in particular an oxidoreductase enzyme, a mediator, a free amine and an oxidizing agent. This system is employed for bleaching a chemical pulp which has been delignified with oxygen beforehand. This system has the drawbacks of generating effluents that are harmful to the environment, and of giving rise to high production costs.
Optimizing the enzymatic activity of laccases, moreover, has been studied in document U.S. 2008/0189871. This document proposes an LMS system (Laccase Mediator System) comprising a mediator derived from 2,6-dimethoxyphenol. This system is employed for bleaching a cloth. It is stated on the one hand that it may be used during the manufacture of pulp and on the other hand that it may be used during the bleaching of a pulp.
The methods and the products used in the prior art, therefore, do not provide complete satisfaction.
In particular there is still a need existing to reduce the energy demand of mechanical pulp production methods and to ensure, furthermore, a mechanical pulp having papermaking qualities that are equivalent to or an improvement on those obtained by the known techniques. There is also a need existing for a mechanical pulp having a degree of whiteness greater at the outcome of refining, and/or developing an improved capacity for bleaching, relative to those obtained by the known techniques. A need exists, lastly, to reduce the amount of chemical products required to bleach a mechanical pulp while ensuring an equivalent or improved degree of whiteness in relation to the mechanical pulps obtained with the techniques of the prior art.
SUMMARY OF THE INVENTION
The present invention accordingly provides a method for producing a mechanical paper pulp.
More specifically the invention relates in the first instance to a process for producing a mechanical paper pulp, comprising at least:
a step of impregnating an untreated wood, comprising contacting the untreated wood with an impregnating composition comprising at least one laccase enzyme and a mediator of formula (I):
in which R1 and R2 are identical or different groups selected from a hydrogen atom and a saturated or unsaturated, linear or branched hydrocarbon chain comprising from 1 to 14 carbon atoms, it being possible for each hydrocarbon chain to be substituted by one or more functional groups selected from —OH, —SO3, benzyl, amino, mercapto, keto, and carboxyl, where R1 and R2 may together form a cyclic structure (as in piperidinyloxy compounds), to give an impregnated wood; and
a step of mechanically refining the impregnated wood, so as to obtain a mechanical paper pulp.
More preferably, the process for producing a mechanical paper pulp of the invention comprises at least:
a step of impregnating an untreated wood, comprising contacting the untreated wood with an impregnating composition comprising at least one laccase enzyme and a mediator of formula (I):
in which R1 and R2 are identical or different groups selected from a hydrogen atom or a C1 to C8 alkyl chain, to give an impregnated wood; and
a step of mechanically refining the impregnated wood, so as to obtain a mechanical paper pulp.
Further preference among the mediators of formula (I) is given to those for which at least one of R1 and R2 is different from H. Even further preference is given to those for which R1=R2 and they each represent a C1-C8, more particularly C1-C6, and more preferably C1-C4 alkyl radical. One particularly preferred example would be N,N-diethylhydroxylamine.
The invention likewise relates to the impregnating composition employed in this method.
The invention also provides for the use of said impregnating composition in a method for producing mechanical paper pulp, for lowering the energy consumption of said method.
The invention further provides for the use of said impregnating composition in a method for producing mechanical paper pulp, for enhancing the whiteness of said pulp.
The invention also provides for the use of said impregnating composition in a method for producing mechanical paper pulp comprising a step of mechanical refining, said impregnating composition being used before the step of mechanical refining.
The invention provides, lastly, a papermaking process comprising the production of a mechanical paper pulp by the above method, and also to the use of this mechanical paper pulp for manufacturing paper.
The present invention may allow for the drawbacks of the prior art to be overcome. More particularly, it provides a method for producing mechanical paper pulp that is more energy-saving and which ensures a pulp and paper whose papermaking qualities are equivalent to or an improvement over those of the known methods. It likewise provides a mechanical paper pulp having a degree of whiteness that is greater at the end of refining and/or that develops a better capacity for bleaching, relative to the mechanical paper pulps obtained with the known methods. The invention also permits a reduction in the amount of chemical products to be employed for bleaching the mechanical paper pulp while ensuring a degree of whiteness at the outcome of bleaching that is at least equivalent to, or even greater than that of the mechanical paper pulps produced with the known methods. This is accomplished by virtue of a step of impregnating wood with a specific impregnating composition, prior to its refining.
More particularly, the composition according to the invention oxidizes the phenolic and nonphenolic units in the lignin, thereby weakening the bonds between the fibers. The Applicant has, in particular, developed an impregnating composition which acts specifically on the cell wall of the fibers, allowing the cohesion between the fibers to be reduced while at the same time preserving the fibers. Therefore, when the composition of the invention is used on wood prior to its refining, it allows a reduction in the energy it would be necessary to supply during refining in order to separate the fibers of the wood if no pretreatment was carried out, or if a prior-art technique was employed instead. Moreover, the length of the fibers obtained from the initial wood, and their strength, are preserved in the mechanical paper pulp produced and in the paper obtained from it.
Lastly, in contrast to the compositions proposed by the prior art, the impregnating composition according to the invention is inexpensive, available in large quantity and less toxic for the environment.
DEFINITIONS
A “mediator”, according to the invention, is a compound which enhances the capacity of an enzyme to oxidize wood.
“Wood” means the entirety of the strong secondary (support, transfer, and reserve) tissues which form the trunks, branches, and roots of woody plants, in the sense of standard NF B 50-003.
By “untreated” wood is meant the condition of wood prior to its treatment with an impregnating composition according to the invention, and by “impregnated” wood is meant the condition of wood after its treatment with an impregnating composition according to the invention.
Unless otherwise specified, the percentages of material stated are percentages by weight.
Unless otherwise indicated, the percentages by weight of wood are given by weight of dry wood. “Dry wood” means that the wood has been dried in an oven in accordance with standard ISO 638:2008, namely at a temperature of from 103° C. to 107° C., for a time which is at least 30 minutes and does not exceed 16 hours, at atmospheric pressure.
The “consistency” of the mechanical paper pulp denotes the pulp concentration as defined in the ISO 4119 Standard of June 1996. This is the ratio of the dry mass of material which may be filtered from a sample of pulp in suspension, to the mass of the unfiltered sample, the test being carried out in accordance with said International Standard. The concentration of pulp is expressed herein as a percentage by mass.
Unless otherwise specified, the percentages by weight of mechanical paper pulp are given by weight of dry mechanical paper pulp. “Dry mechanical paper pulp” means the dry mass of material in a sample of pulp in suspension, as defined in the above ISO 4119 Standard, as measured after filtration and drying in accordance with said Standard.
Unless instructed otherwise, the measurements are performed at atmospheric pressure.
When reference is made to ranges, the expressions of the type “of from . . . to” include the endpoints of the range. Conversely, the expressions of the type “of between . . . and . . . ” exclude the endpoints of the range.
DETAILED DESCRIPTION
The invention is now described in more detail and nonlimitatively in the description which follows.
In schematic terms, the method for producing mechanical paper pulp according to the invention comprises at least:
a step of impregnating untreated wood, comprising contacting the untreated wood with an impregnating composition according to the invention, to give an impregnated wood, a step of mechanical refining of the impregnated wood, to give a mechanical paper pulp.
In more detail, the method for producing mechanical paper pulp of the invention comprises, preferably in this order, the following steps:
optionally an operation of steaming an untreated wood, optionally an operation of pressing an untreated wood, at least one step of impregnating an untreated wood with an impregnating composition according to the invention, to give an impregnated wood, optionally an operation of steaming the impregnated wood, at least one step of mechanically refining the impregnated wood, to give a mechanical pulp, optionally a step of chelating the mechanical pulp, optionally an operation of bleaching the mechanical pulp.
The starting material used is untreated wood.
According to one embodiment, the untreated wood is selected from coniferous woods, deciduous woods, or mixtures thereof. Suitable coniferous woods include Douglas fir, spruce, Aleppo pine, maritime pine, black pine, Scots pine, loblolly pine, red cedar ( Thulya plicata ), or mixtures thereof. Suitable deciduous woods include poplar, aspen, birch, maple, oak, eucalyptus, acacia, beech, chestnut, hornbeam, elm, or mixtures thereof. Preference is given to using spruce, poplar, eucalyptus, or a mixture thereof.
According to one embodiment, for producing a chemithermomechanical pulp (CTMP), the untreated wood may be selected from coniferous woods such as those stated above, deciduous woods such as those stated above, or else bamboo, hemp, cereal straw, as for example wheat straw or rice straw, cotton, or mixtures thereof.
According to one preferred embodiment, the untreated wood is in the form of chips. The term “chips” is employed in the sense conventional to the skilled person. It designates wood particles obtainable by any industrial process conventionally used in the mechanical pulp field. The size of the chips is typically subject to distribution in accordance with the standard SCAN-CM 40:01. This form facilitates in particular the subsequent impregnation treatment of the wood, and enhances its effectiveness. The chips may typically be obtained from debarked and cut logs of untreated wood, or from residual byproducts of the wood industry.
According to one embodiment, the wood, before or after the impregnating step, preferably before the impregnating step, undergoes at least one pretreatment selected from a thermal pretreatment, a chemical pretreatment, a mechanical pretreatment, or a combination of these. Suitable thermal pretreatment includes steaming, hot-water treatment, or a combination of these. Suitable chemical pretreatment includes an impregnating treatment on the wood with at least one chemical agent selected from an acid, a base, an oxidizing agent, a reducing agent, a chelating agent, a stabilizer, a surfactant, an enzyme, or mixtures thereof. Suitable mechanical pretreatment includes pressing.
According to one embodiment, the wood, before or after the impregnating step, preferably before the impregnating step, undergoes steaming, which gives the wood a uniform moisture content. Steaming comprises contacting the wood with steam. Steaming is preferably performed at atmospheric pressure. Steaming lasts preferably for from 5 to 30 minutes, more preferably from 10 to 20 minutes.
According to one embodiment, the untreated wood, before or after the impregnating step, preferably before the impregnating step, undergoes pressing. Pressing may be carried out using any means known to the skilled person, preferably using a compression device such as a screw press or a cylinder press.
The aforementioned embodiments may advantageously be combined with one another: according to one preferred embodiment, the untreated wood is initially in the form of chips, and the chips undergo steaming as defined above; according to another preferred embodiment, the untreated wood, before the impregnating step, undergoes steaming followed by pressing as defined above.
According to one particular embodiment, the wood does not undergo chemical pretreatment before the impregnating step, in particular no acid washing or chelation treatment.
The various pretreatments identified above may be performed before or after the impregnating step. They may also be repeated if necessary. For example, it is possible to perform one of these pretreatments before the impregnating step, to carry out the impregnating step, and then to repeat said pretreatment after the impregnating step.
The production method according to the invention comprises a step of impregnating untreated wood, comprising contacting the untreated wood with an impregnating composition according to the invention, to give an impregnated wood. Said impregnating composition comprises at least one laccase enzyme and a mediator with a specific formula. The impregnating composition according to the invention accordingly comprises a mediator of formula (I):
in which R1 and R2 are identical or different groups selected from a hydrogen atom or a C1 to C8 alkyl chain.
R1 and R2 are preferably identical or different groups selected from a hydrogen atom or a C1 to C4 alkyl chain. More preferably, R1 and R2 are identical or different C1 to C4 alkyl chains. Even more preferably, R1 and R2 are identical alkyl chains of formula C2H5: the preferred mediator is therefore diethyl hydroxylamine (DEHA).
The mediator may be present in the impregnating composition in pure form, in solution in water, or in the form of one of its salts.
The mediator content of the impregnating composition is preferably from 0.1% to 10% by weight, preferably from 0.15% to 4.5% by weight, preferably from 0.19% to 4% by weight, preferably from 0.19% to 3% by weight, or even from 0.23% to 2% by weight, relative to the total weight of the impregnating composition.
The mediator content, relative to the mass of dry untreated wood for treatment, is preferably from 0.1% to 10%, from 0.2% to 10%, from 0.2% to 5%, more preferably from 0.2% to 0.5%, or even from 0.25% to 0.5%, by weight of dry wood.
The laccase enzyme may be selected from class EC 1.10.3.2 of the enzymes nomenclature. Mycellophthora laccase is particularly preferred.
The laccase enzyme may be in crude extract form or in purified or semipurified form.
The amount of 1000 LAMU/mL laccase solution, relative to the mass of dry untreated wood for treatment, is preferably from 0.1 to 10 L/t, from 1 to 5 L/t, more preferably from 1 to 2 L/t of the dry untreated wood.
The amount of 1000 LAMU/mL laccase solution in the impregnating composition is preferably from 0.01% to 10% by weight, from 0.05% to 5% by weight, from 0.05% to 1% by weight, more particularly from 0.09% to 0.2% by weight, relative to the total weight of the impregnating composition.
The impregnating composition according to the invention may further comprise one or more additives usual for the skilled person, provided that their presence does not diminish the efficacy of the composition. Such additives may in particular be selected from the following: an enzyme other than laccase, an oxidizing agent, a reducing agent, an acid, a base, a chelating agent, a stabilizer, a surfactant, and combinations thereof. When present, the amount of total additive in the impregnating composition is preferably less than 3% by weight, more particularly less than 2% by weight, relative to the total weight of the composition. According to one embodiment, the impregnating composition does not comprise additive.
According to one embodiment, the impregnating composition is an aqueous solution. The water content of the composition then corresponds to the balance to 100% by weight of the sum of the amounts of mediator, of enzyme, and of optional additives.
According to one embodiment, the impregnating composition is used at a rate of 0.1 to 12 L/kg of the dry untreated wood for impregnation, preferably at a rate of from 1 to 10 L/kg of the untreated wood for impregnation. The excess impregnating composition may advantageously be recycled for carrying out a new impregnating step on another untreated wood or on the impregnated wood.
According to one embodiment, the contacting of the untreated wood with the impregnating composition comprises (or even consists of) spraying the impregnating composition onto the untreated wood, or immersing the untreated wood in a bath of impregnating composition.
According to one particular embodiment, the untreated wood is immersed in the impregnating composition for a time sufficient to allow impregnation of the wood with impregnating composition, after which the wood is withdrawn from the composition and left to incubate for a time sufficient to allow the enzyme to act on the wood. As a variant, the untreated wood is immersed in the impregnating composition and is left therein to incubate for a time sufficient to allow the enzyme to act on the wood. Incubation may be performed in any suitable device known to the skilled person, as for example in a storage vat.
According to one preferred embodiment, the contacting of the untreated wood with the impregnating composition is performed by spraying chips of untreated wood, which have been compressed, straight from a compression screw into a bath of impregnating composition. This allows optimum absorption by the chips (the chips draw up the composition in the manner of a sponge) and promotes the action of the composition at the core of the wood fibers.
Contacting of the untreated wood with the impregnating composition is preferably performed for a time of from 5 minutes to 240 minutes, from 25 minutes to 180 minutes, from 45 minutes to 120 minutes, more preferably from 55 min to 65 min. The impregnating composition is preferably employed at a temperature of from 35 to 80° C., from 40 to 70° C., more particularly from 45 to 55° C. It is preferably employed at a pH of from 3 to 11, from 4 to 7, more preferably from 4.5 to 5.5. Such conditions are advantageous for optimizing the efficacy of the composition according to the invention.
The impregnating step may be discontinued by steaming (contacting the impregnated wood with steam) or by washing with water, in order to halt the activity of the enzyme. The duration of the steaming or the washing with water is preferably from 1 to 10 minutes, more preferably from 3 to 7 minutes. Preference is given to steaming at atmospheric pressure.
The impregnating step is advantageously repeated a number of times, more particularly two to four times. The various aforementioned embodiments may also be combined with one another. Lastly, it should be noted that the impregnating composition may be prepared separately and then contacted with the untreated wood, as explained above, but may also be prepared directly in contact with the untreated wood. In this case, the various compounds of the impregnating composition are added successively and directly to the untreated wood.
Further to impregnation, the wood may be subjected to an additional treatment, referred to as aftertreatment. This aftertreatment involves contact with a chemical composition comprising an alkaline agent and a reducing agent. This aftertreatment is advantageous for softening the lignin and developing the mechanical characteristics of the fibers. It is advantageous more particularly when the aim is to produce a chemithermomechanical pulp (CTMP).
This step is preferably performed after the impregnating step, in order to prevent potential inhibition of the enzymes in the impregnating composition. It may be performed before or after the refining step. It is preferably performed between the impregnating step and the refining step, thereby allowing a greater energy saving to be made in the refining.
According to one embodiment, the contacting of the wood with the chemical composition comprises spraying of said composition onto the wood, or immersion of the wood into a bath of said composition.
According to one embodiment, the alkaline agent is selected from sodium hydroxide, magnesium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, sodium silicate, or mixtures thereof. The alkaline agent is preferably selected from sodium silicate, sodium hydroxide, or a mixture thereof.
According to one embodiment, the reducing agent is selected from sodium sulfite Na 2 S 2 O 3 , sodium bisulfite NaHSO 3 , or a mixture thereof.
According to one embodiment, the alkaline agent is present in an amount of from 0.1% to 20% by weight, preferably from 1% to 10% by weight, relative to the weight of wood.
According to one embodiment, the reducing agent is present in an amount of from 0.1% to 30% by weight, preferably from 1% to 20% by weight, relative to the weight of wood.
The chemical aftertreatment step is preferably performed at a temperature of from 10° C. to 150° C., more particularly from 60° C. to 120° C. It is preferably performed for a time of from 1 minute to 120 minutes, preferably from 1 to 60 minutes.
The chemical aftertreatment step may be brought to an end by any means that stops the reaction of the chemical agents on the wood, as for example by washing with water.
The chemical aftertreatment step may advantageously be repeated a number of times, more particularly two times to four times, therefore allowing the papermaking capacities of the fibers to be reinforced further.
After the impregnating step (and the optional chemical aftertreatment step), the impregnated wood is mechanically refined, to give a mechanical paper pulp. The mechanical refining comprises primary mechanical refining (also called defibration), which is intended to pulp the wood optionally, followed by at least one secondary mechanical refining, which is intended to develop the papermaking capacities of the fibers. The secondary refining is optionally followed by one or more subsequent mechanical refining operations (tertiary refining, refining of wastes, etc.).
Mechanical refining is preferably carried out under pressure in order to allow more selective separation of the fibers.
Primary refining may be performed by milling or grinding the wood on a grindstone (in a stream of water) or in a disk refiner.
According to one embodiment, the primary refining of the wood is performed in a disk refiner. The pressure is preferably set so as to achieve a refining temperature of between 105° C. and 115° C. The pressure is advantageously from 0.5 to 5 bar, preferably from 1 to 3 bar. The rotary speed of the disks is preferably from 1000 to 5000 revolutions/minute, preferably from 1000 to 3000 revolutions/minute.
According to one embodiment, the secondary refining of the wood is performed in a disk refiner. Secondary refining is preferably performed under a pressure of from 0.1 to 5 bar, preferably from 0.5 to 3 bar. The rotary speed of the disks is preferably from 1000 to 5000 revolutions/minute, preferably from 1000 to 3000 revolutions/minute.
According to one embodiment, secondary refining is performed such that the resultant pulps have a degree of dewatering of from 250 to 50 mL CSF (Canadian Standard Freeness).
The refining step or steps subsequent to defibration may comprise a plurality of stages. For example, after defibration, the product may be separated into an accepted fraction and a rejected fraction, and the rejected fraction may be refined before being blended with the accepted fraction. Such intermediate separations may be provided a plurality of times.
At the outcome of refining, a mechanical paper pulp is obtained which may in particular be:
a defibrator mechanical pulp (SGW) obtained from logs or blocks refined at atmospheric pressure using grinding disks; a pressure defibrator mechanical pulp (PGW) obtained from logs or blocks refined under pressure using grinding disks; a refiner mechanical pulp (RMP) obtained from chips or shives in refiners operating at atmospheric pressure; a thermomechanical pulp (TMP) or high-temperature thermomechanical pulp (HTMP) obtained from chips or shives in refiners after heat treatment of the wood by steaming at elevated pressure; a chemithermomechanical pulp (CTMP) obtained by chemical treatment in the presence of a chemical composition comprising an alkaline agent and a reducing agent at a temperature greater than or equal to 100° C. and by refining under pressure.
At the end of refining, a mechanical pulp is obtained which preferably has a brightness, measured in accordance with standard ISO 2470, of greater than or equal to 50%, preferably greater than or equal to 55%, ideally greater than or equal to 57%.
The specific energy saving achieved by virtue of the invention is advantageously greater than or equal to 10%, or even greater than or equal to 12%, or even greater than or equal to 14%, or even greater than or equal to 18% or even greater than or equal to 32%, by comparison with a method for producing a mechanical pulp obtained by refining preimpregnated wood under the same conditions, but with water.
Chelation, when practiced, comes preferably after the impregnating step (that is, when the impregnating step has been accomplished), advantageously after refining, in order to prevent any possible inhibitory interaction with the enzyme. Chelation comprises contacting the mechanical paper pulp obtained from refining with a chelating composition comprising a chelating agent, said chelating composition being preferably an aqueous solution.
The chelating agent may be any chemical compound conventionally used for this purpose in the art. Preferably it involves ethylene diamine tetraacetic acid or one of its sodium salts, or diethylene triamine pentaacetic acid or one of its sodium salts.
The chelating agent possesses a particular affinity for the metal cations present as traces in the mechanical pulp. The objective of the chelation treatment is to neutralize these cations by sequestering them and withdrawing them from the mechanical pulp by washing of said pulp. Carrying out the chelating step makes a contribution to enhancing the performance level of a subsequent bleaching treatment (in particular with hydrogen peroxide).
The amount of chelating agent used in the chelating step is preferably from 0.05% to 3% by weight, preferably from 0.1% to 2% by weight, preferably from 0.2% to 1% by weight, more particularly from 0.3% to 0.5% by weight, relative to the weight of dry mechanical pulp.
The duration of the chelating step is preferably greater than or equal to about 30 minutes.
The chelating step is performed at a temperature of preferably from 4° C. to 95° C., preferably from 25° C. to 85° C., more preferably from 35° C. to 80° C. A temperature of about 60° C. is particularly appropriate.
The consistency of the mechanical pulp during the chelating step is preferably from 0.5% to 20% by weight of dry mechanical pulp, preferably from 2 to 15% by weight of dry mechanical pulp, more preferably from 3 to 12% by weight of dry mechanical pulp, relative to the weight of nondry mechanical pulp.
Bleaching comes preferably after chelation (or after refining, if no chelation is carried out), in other words when the chelating step (or the refining step if chelation is not carried out) has been accomplished.
Bleaching comprises contacting the mechanical paper pulp from the chelating step (or refining step if chelation is not carried out) with a bleaching composition.
The consistency during the bleaching step is preferably from 1% to 50% by weight of dry mechanical pulp, preferably from 10 to 40% by weight of dry mechanical pulp, more preferably from 20 to 30% by weight of dry mechanical pulp, relative to the weight of nondry mechanical pulp.
Bleaching has reaction kinetics that are more rapid at high consistency (whereas, for chelation, the reaction kinetics are rapid even at low consistency). It is possible to increase the consistency of the mechanical pulp, by pressing it, for example, and by removing filtrates comprising, in particular, the chelated metals.
Contacting takes place preferably by simple mixing of the bleaching composition with the pulp. The type of apparatus used for mixing is adapted to the consistency of the pulp: direct mixing by means of an injection pump if the consistency is low or medium (less than 10%); blender or mixer for a higher consistency (up to about 40%).
The bleaching composition is preferably an aqueous solution. The bleaching composition preferably comprises a bleaching agent and an alkaline agent.
The bleaching agent may be any chemical compound conventionally used for this purpose in the art. Preference is given to hydrogen peroxide or sodium hydrosulfite.
The amount of bleaching agent used is preferably from 0.5% to 10% by weight, preferably from 1% to 8% by weight, preferably from 1.5% to 6% by weight, more particularly from 2% to 4% by weight, relative to the weight of dry mechanical pulp.
The alkaline agent may be selected from alkaline metal and alkaline earth metal oxides, hydroxides, silicates, and carbonates, ammonia, aqueous ammonia, and mixtures thereof. The preferred basic species for selection of the alkaline agent including potassium hydroxide, sodium hydroxide, magnesium hydroxide, calcium hydroxide, sodium carbonate, sodium silicate, magnesium carbonate, and mixtures thereof. Sodium hydroxide, potassium hydroxide, or a mixture thereof is particularly preferred. The alkaline agent of the bleaching composition preferably comprises sodium silicate. Sodium silicate has an auxiliary function of stabilizing the bleaching agent (especially the hydrogen peroxide). In the bleaching composition it is also possible to provide another stabilizing agent, in addition to or instead of the sodium silicate. Polyhydroxyacrylate compounds constitute possible stabilizing agents.
The amount of alkaline agent used is preferably from 0.5% to 10% by weight, preferably from 1% to 6% by weight, preferably from 1.4% to 4% by weight, more particularly from 1.6% to 2.5% by weight, relative to the weight of dry mechanical pulp.
The bleaching composition may further comprise a chelating agent as defined above, especially if the chelating step is not carried out or ended at incomplete chelation.
It should be noted that the bleaching composition may be prepared separately and then contacted with the mechanical pulp, but it may also be prepared directly in contact with the mechanical pulp. In this second case, the various compounds of the bleaching composition are added successively and directly to the mechanical pulp.
The duration of the bleaching step varies with the type of agent used.
In the case of hydrogen peroxide, this duration is preferably from 10 minutes to 8 hours, preferably from 30 minutes to 6 hours, more preferably from 2 hours to 4 hours.
The bleaching step is carried out at a temperature of preferably from 4° C. to 95° C., preferably from 25° C. to 85° C., more preferably from 35° C. to 80° C. A temperature of about 70° C. is particularly suitable.
The bleaching step may be repeated a number of times, as for example twice.
At the end of the first bleaching, a mechanical pulp is obtained which preferably has a brightness, measured in accordance with standard ISO 2470-2:2008, of greater than or equal to 57%, more preferably of greater than or equal to 60%, ideally greater than or equal to 62% or even greater than or equal to 65%.
The invention relates, lastly, to a papermaking process that comprises producing mechanical paper pulp by the method above, then using this mechanical pulp to manufacture paper.
The mechanical pulp may in particular be dried and converted to sheets in a paper machine conventional in the art.
The mechanical pulp may also be introduced into a wet machine, in order to be dried and preformed into sheets. The sheets may be baled, before being transferred to a papermaking plant, where they may undergo subsequent treatments.
The tearing resistance of the paper obtained by implementation of the present invention (as measured in accordance with standard NF EN 21974 after the mechanical pulp has been formed into sheets in accordance with standard NF EN 5269-1) is advantageously increased by 3%, or even 9%, or even 11%, relative to a mechanical pulp obtained by refining wood preimpregnated with water.
Measurement Parameters
The activity of the laccase enzyme is expressed in LAMU/mL. One LAMU unit corresponds to the amount of laccase enzyme which, under given conditions (pH 7.5 and 30° C. temperature), breaks down 1 μmol of syringaldazine per minute. This activity can be determined on the basis of spectrophotometric absorbance measurements. The reason is that, in the course of the reaction in which a laccase (E.C. 1.10.3.2), p-diphenol:dioxygene oxidoreductase, catalyzes the oxidation of syringaldazine (4,4′-[azinobis(methanylylidine)]bis(2,6-dimethoxyphenol)) to the corresponding quinone (4,4′-[azobis(methanylylidine)]bis(2,6-dimethoxycyclohexa-2,5-dien-1-one), there is a change in absorption by the syringaldazine at a wavelength of 530 nm.
The measurement uses:
a 25 mM tris/malate buffer solution (pH 7.5) (prepared from 25 mL of a 1.0 M aqueous solution of tris(hydroxymethyl)aminomethane, 5 mL of a 1.0 M aqueous solution of maleic acid, and the amount of water sufficient to give 1 L of buffer solution),
a 0.28 mM syringaldazine solution (prepared by diluting 25 mL of a 0.56 mM alcoholic solution of syringaldazine in the amount of water sufficient to give 50 mL of syringaldazine solution, the 0.56 mM alcoholic syringaldazine solution being itself obtained by dissolution of 10.0 mg of syringaldazine (Sigma S-7896) in the amount of 96% ethanol sufficient to give 50 mL of alcoholic syringaldazine solution),
a 6% by weight aqueous solution of ethanol,
an enzyme dilution solution (containing 25.0 g of PEG 6000, 5.0 g of Triton X-100, and an amount of water sufficient to give 0.5 L of solution). The test laccase samples are diluted by a factor F using this solution, to approach an activity of 0.18 LAMU/mL.
The absorbance measurements are carried out with the spectrophotometer at an operating temperature of 30° C.: a tank is prepared with 1 mL of buffer solution, 25 μL of diluted laccase, and finally 75 μL of a 0.28 mM syringaldazine solution are added. After brief mixing, acquisition of the absorbance measurement is initiated straight away, for radiation with a wavelength of 530 nm.
The activity is calculated according to the following formula:
Activity (LAMU/mL)=Δ A 530nm ×0.677× F
where ΔA 530nm is the difference in absorbance at 530 nm measured over the 60-90 seconds period, and F is the enzyme dilution factor.
The dewatering index, referred to as “Canadian Standard Freeness” (CSF), is measured in accordance with international standard ISO 5267-2. It conveys the ease with which water can be extracted from a mechanical paper pulp. The smaller the index, the poorer the dewatering of the mechanical pulp. This parameter is an indicator of the degree of refining achieved during mechanical refining of the pulp.
The brightness of the mechanical pulp is determined by measuring its diffuse blue reflectance factor as defined in standard ISO 2470-2: 2008.
For a test X, the gain in brightness corresponds to the difference between brightness measured at the end of bleaching QP, and the brightness measured at the end of refining.
The total specific refining energy is obtained by adding the values of electrical consumption measured for each of the steps prior to refining and up to its end (for example, compression of wood chips, defibration, and secondary refining).
For a test X, the energy saving achieved corresponds to the difference between the specific refining energy of a reference test, carried out under the same conditions as test X but with use of an abiotic impregnating composition, and the specific refining energy of the test X.
In order to evaluate the resistance of the fibers in the mechanical pulp produced, this pulp is formed into sheets in accordance with standard NF EN 52694, and the tearing resistance of the sheets is measured in accordance with standard NF EN 21974.
EXAMPLES
The examples which follow illustrate the invention without limiting it.
The starting materials used are as follows:
fresh Norwegian spruce chips, supplied by the Holmen company,
chips from fresh poplar logs, supplied by a forestry enterprise in the Lyons region,
fresh Spanish eucalyptus chips, supplied by the Ence company,
Myceliophthora laccases sold by the Novozymes company under reference NS51003, having an activity of 1000 LAMU/mL as measured in accordance with the protocol indicated above,
diethylhydroxylamine (DEHA) sold by the Arkema company,
4-hydroxy-3,5-dimethoxybenzaldehyde (syringaldehyde),
diethylene triamine pentaacetic acid (DTPA),
hydrogen peroxide,
sodium silicate,
sodium hydroxide,
magnesium sulfate.
Table 1: Impregnating Composition
For each test, an impregnating composition in accordance with table 1 is prepared (the percentages are given by weight relative to the total weight of the composition). For this purpose, the water is heated to 50° C., the pH is adjusted to 5 by addition of sulfuric acid, and the commercial laccase solution and, lastly, the DEHA (or the syringaldehyde, where appropriate) are added. The impregnating compositions of tests 1, 6, and 9 are abiotic reference compositions. The compositions of tests 2, 4, and 5 are comparatives. The compositions in accordance with the invention are those of tests 3, 7, 8, 10, and 11.
The effective absorption capacity of the dry chips is 1.04 L of impregnating composition per kilogram of dry wood chips. For each test, the composition is used in excess, at a rate of 70 L per 10 kg of dry wood chips.
Laccase solution Syring- at 1000 alde- Water LAMU/mL DEHA hyde at pH 5 TMP Test 1 100% (ref) Test 2 0.192% 1.92% balance to 100% (comp) Test 3 0.192% 1.92% balance to 100% (inv) Test 4 0.192% balance to 100% (comp) Test 5 1.92% balance to 100% (comp) TMP Test 6 100% (ref) Test 7 0.096% 0.48% balance to 100% (inv) Test 8 0.096% 0.24% balance to 100% (inv) CTMP Test 9 100% (ref) Test 10 0.096% 1.92% balance to 100% (inv) Test 11 0.096% 0.192% balance to 100% (inv)
Tests 1 to 5: Thermomechanical Pulping (TMP) and Bleaching
Spruce wood chips are subjected to steaming at atmospheric pressure for 15 minutes, then introduced into a compression screw (6-inch model Modular Screw Device Impressafiner™ from Andritz AG), connected to a vat containing the impregnating composition. At the screw exit, the compressed chips are expelled directly into the impregnating composition, where they are left to incubate for 1 hour. The impregnating composition is extracted, and the chips are then subjected to steaming for 5 minutes to halt the enzymatic activity.
The chips pretreated in this way are transferred to a pilot-scale mechanical paper pulper (disk refiner), in which they are mechanically defibrated and then refined. Defibrating (primary refining) is performed at a pressure of 2 bar with disks rotating at 3000 revolutions/min. Secondary refining is performed at a pressure of 1 bar. The spacing between the disks is adjusted gradually so as to give five mechanical pulps with dewatering indices of 250 mL to 50 mL CSF. The brightness of the five mechanical pulps is measured according to standard ISO 2470-2:2008.
After refining, each resulting TMP mechanical pulp is bleached by a two-step method comprising a chelating step (Q) followed by hydrogen peroxide bleaching (P). In step Q, the consistency of the mechanical pulp is adjusted to 10% by weight. Step Q comprises contacting this mechanical pulp, at a temperature of 60° C. for 30 minutes, with 0.4% by weight of diethylene triamine pentaacetic acid (DTPA), relative to the total weight of dry mechanical pulp. During step P, the consistency of the mechanical pulp obtained at the outcome of step Q is adjusted to 25% by weight. Step P comprises contacting this mechanical pulp, at a temperature of 70° C. for 120 minutes, with a bleaching composition comprising 3% of hydrogen peroxide, 1.9% of sodium hydroxide, and 2% of sodium silicate, in percentages by weight relative to the total weight of dry mechanical pulp. The brightness of the five mechanical pulps is measured according to standard ISO 2470-2:2008.
The mechanical pulps are subsequently formed into sheets in accordance with standard NF EN 5269-1. The tearing resistance of the sheets is measured according to standard NF EN 21974.
The specific energy consumption is calculated as described earlier on above—that is, by adding up the energy consumption at each step in the mechanical pulp production method up to the end of refining: 1st steaming, compression/expulsion, 2nd steaming, defibration and subsequent refining operations.
The results are reported in table 2 below, following interpolation of the values to 100 mL CSF.
TABLE 2 TMP Test 1 Test 2 Test 3 Test 4 Test 5 (ref) (comp) (inv) (comp) (comp) After refining Specific energy 2480 2350 2170 2380 2360 consumed (kWh/t) Energy saving/ref ref 52% 12.5% 4.0% 4.8% Brightness (%) 54.2 52.1 54 53.9 54.3 (B R ) After bleaching Brightness after QP (%) 68.5 65.7 70.8 67.6 68 (B QP ) Brightness gain 26.4% 26.1% 31.1% 25.4% 25.2% (B QP − B R )/B R After sheet formation Tearing resistance 6.2 6 6.4 5.8 4.8 (mNm 2 /g)
Concerning the specific energy consumption of refining, test 3 according to the invention shows that:
the invention allows a significant reduction in the specific energy consumption of refining; the combination of laccase and DEHA allows a greater reduction in the specific energy consumption of refining than the compounds taken separately (tests 4 and 5); in combination with laccase, DEHA allows a greater reduction in the specific energy consumption of refining than syringaldehyde (test 2).
Concerning the brightness of the mechanical pulp, test 3 according to the invention shows that:
the invention allows a significant increase in the brightness of the mechanical pulp produced (test 1); the combination of laccase and DEHA allows an increase in the brightness of the pulp, in contrast to the compounds taken separately (tests 4 and 5 versus test 1); in combination with laccase, DEHA increases the brightness of the pulp more than syringaldehyde (test 2).
Concerning the tearing resistance of the paper, test 3 shows that the invention preserves the papermaking qualities of the fibers.
Tests 6 to 8: Effect of the Amount of Compounds in the Impregnating Composition
These complementary tests are carried out to determine the effect of the amount of reagents used in the impregnating composition according to the invention. The impregnating composition used for each test is given in table 1. The impregnating composition of test 6 corresponds to an abiotic reference composition. The compositions of tests 7 and 8 are in accordance with the invention. The procedure is exactly the same as for tests 1 to 4. The results are reported in table 3 below.
TABLE 3
TMP
Test 6
Test 7
Test 8
(ref)
(inv)
(inv)
After
Specific energy
2451
2006
2595
Refining
consumed (kWh/t)
Energy saving/ref
ref
18.2%
−5.9%
Brightness (%) (B R )
54.2
55
57.2
After
Brightness after QP (%)
70
73
73.5
Bleaching
(B QP )
Brightness gain
29.2%
32.7%
28.5%
(B QP − B R )/B R
After
Tearing resistance
6.44
7.05
7.20
sheet
(mNm 2 /g)
formation
Test 7 (by comparison with test 6) shows that, even when the amounts of laccase and DEHA are reduced, the impregnating composition according to the invention reduces the specific energy consumption of refining, increases the brightness of the mechanical pulp produced, and preserves the strength of the paper obtained from said pulp.
Test 8 (by comparison with tests 6 and 7) shows that below a certain mediator content, the impregnating composition no longer reduces the specific energy consumption of refining, but still increases the brightness of the mechanical pulp produced and preserves the strength of the paper obtained from said pulp.
Tests 9 to 11: Chemithermomechanical Pulping (CTMP) and Bleaching
Poplar wood chips are pulped according to steps of steaming, compression, and impregnation that are identical to those of tests 1 to 4. The impregnating composition used for each of the tests is indicated in table 1. In particular, the impregnating composition of test 9 corresponds to an abiotic composition which serves as reference. The compositions of tests 10 and 11 are in accordance with the invention.
A second treatment of the chips is performed by addition to the vat of 2% by weight of sodium sulfite and 1% by weight of sodium hydroxide, relative to the total weight of dry chips. The temperature of the medium is raised to 125° C., and the chips are left to impregnate for 15 minutes.
The impregnated chips are subjected to defibration at a pressure of 2 bar with disks rotating at 3000 revolutions per minute, and then to a second mechanical refining at atmospheric pressure. The spacing between the disks is adjusted progressively so as to give five mechanical pulps with dewatering indices of from 400 to 100 mL CSF. The brightness of the five mechanical pulps is determined according to standard ISO 2470-2:2008.
After refining, each mechanical pulp CTMP obtained is subjected to bleaching comprising three steps: one chelating step (Q), followed by two successive treatments with hydrogen peroxide (PP).
During step Q, the consistency of the mechanical pulp is adjusted to 10% by weight. Step Q comprises the contacting, at a temperature of 60° C. for 30 minutes, of this mechanical pulp with 0.4% by weight of diethylene triamine pentaacetic acid (DTPA), relative to the total weight of dry mechanical pulp.
During the first step P (P1), the consistency of the mechanical pulp obtained at the end of step Q is adjusted to 14% by weight. Step P1 comprises the contacting, at a temperature of 70° C. for 120 minutes, of this mechanical pulp with a bleaching composition comprising 2.2% of hydrogen peroxide, 1.5% of sodium hydroxide, 1% of sodium silicate, 0.075% of magnesium sulfate, in percentages by weight relative to the total weight of dry mechanical pulp. The brightness of the five mechanical pulps is determined according to standard ISO 2470-2:2008.
During the second step P (P2), the consistency of the mechanical pulp obtained at the end of step P1 is adjusted to 20% by weight. Step P2 comprises the contacting, at a temperature of 70° C. for 120 minutes, of this mechanical pulp with a bleaching composition comprising 3.4% of hydrogen peroxide, 1.7% of sodium hydroxide, 1.6% of sodium silicate, 0.075% of magnesium sulfate, in percentages by weight relative to the total weight of dry mechanical pulp. The brightness of the five mechanical pulps is determined according to standard ISO 2470-2:2008.
The specific energy consumption of the method is calculated for each mechanical pulp, as described earlier on above.
The results are reported in table 4 below, following interpolation of the values to 300 mL CSF.
TABLE 4 CTMP Test 9 Test 10 Test 11 (ref) (inv) (inv) After Specific energy 1060 720 910 refining consumed (kWh/t) Energy saving/ref ref 32.1% 14.2% Brightness (%) (B R ) 37.2 41.6 43.2 After Brightness after QP 46.2 52 56.2 bleaching (%) (B QP ) Brightness after QPP 58.7 62 65.1 (%) (B QPP ) Brightness gain 24.2% 25.0% 30.1% (B QP − B R )/B R Brightness gain 57.8% 49.0% 50.7% (B QPP − B R )/B R
Concerning the specific energy consumption:
tests 10 and 11 (by comparison with test 9), especially test 10, show that the use of an impregnating composition according to the invention during refining produces a significant reduction in the specific energy consumption of refining in the CTMP process.
Concerning the brightness of the mechanical pulp:
tests 10 and 11 (by comparison with test 9) show that the use of an impregnating composition according to the invention during refining produces a brighter mechanical pulp CTMP both at the end of refining and at the end of subsequent bleaching of said pulp; the invention increases the brightness of the mechanical pulp obtained at the end of the first bleaching performed after refining. | A method for producing mechanical paper pulp comprises: impregnating unprocessed wood, whereby unprocessed wood is exposed to an impregnating composition comprising at least a laccase enzyme and a formula mediator (I), wherein R 1 and R 2 are identical or different groups, chosen from among a hydrogen atom, a hydrocarbon chain, linear or branched, saturated or unsaturated, comprising 1 to 14 carbon atoms, wherein each hydrocarbon chain can be replaced by one or more functional groups chosen from among —OH, —SO 3 , benzyl, amino, mercapto, keto or carboxyl, wherein R 1 and R 2 in combination can form a cyclical structure, to achieve impregnation of the wood; and mechanically refining the impregnated wood, such that a mechanical paper pulp is obtained. The disclosure also relates to an impregnating composition used in this method and to the use thereof in a method for producing mechanical paper pulp, as well as to a method for producing paper. | 3 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a method for operating a hearing aid, as well as to a hearing aid system with at least two microphones and a signal processing unit.
[0003] 2. Description of the Prior Act
[0004] Wind frequently causes unpleasant disturbing noises for the wearer of a hearing aid. In order to reduce such wind noise, it is known to fit the microphone openings so as to protect them from the wind as much as possible. It is also known to provide hearing aid microphones with a diaphragm in order to reduce instances of turbulence caused by wind. Such measures are disclosed, for example, in PCT Application WO 00/02419 and German PS 44 20 967.
[0005] German PS 44 98 516 discloses a directional gradient microphone system and a method for operating it employing three microphones and a processor. Owing to the arrangement of the three microphones on a common axis, it is only sound waves incident in the direction of the common axis which are processed after being converted into electric signals, whereas sound waves caused by wind noises, for example, after being converted into electric signals, virtually no longer occur in the output signal of the directional gradient microphone system. This known directional gradient microphone system has the disadvantage, however, that it is possible to suppress wind noises only in conjunction with a strong directional dependence in the reception of incoming sound waves.
[0006] It is a disadvantage in known hearing aids that success in removing wind noises is therefore frequently inadequate.
SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to provide a method for operating a hearing aid or hearing aid system, and a hearing aid or hearing aid system, wherein the comfort in wearing the hearing aid or hearing aid system in windy surroundings is improved.
[0008] The above object is achieved in accordance with the principles of the present invention and that a hearing aid arrangement, such as a hearing aid or a hearing aid system, and a method for operating a hearing aid arrangement, wherein these two microphones are provided in the hearing aid arrangement, and wherein respective signals from the microphones are analyzed to detect whether winded noises are present, and wherein one or more measures for reducing the winded noises are activated automatically if winded noises are detected.
[0009] In contrast to known approaches to the avoidance of wind noises, in which an attempt is made to avoid the wind noises by external measures at the hearing aid, the invention adopts the approach of detecting and removing wind noises by electronic signal processing. This has the advantage that the microphones of the hearing aid can be placed in the housing so as to ensure the best possible reception of the useful signals, nor is there any need to fit an additional diaphragm, which causes undesired damping of the useful signal. The output signals of at least two microphones are analyzed in order to detect wind noises. The microphones in this case can be located in a hearing aid, but it is also possible to evaluate microphone signals of a hearing aid system (consisting, for example, of two hearing aids for one binaural supply).
[0010] The invention is distinguished in that measures for avoiding wind noises are not taken until wind noises are actually present. In order to detect wind noises, the invention utilizes the effect that there is a high degree of correlation between the microphone signals generated by the spatially separate microphones of a hearing aid or hearing aid system, which are caused by useful sound, indeed even by noise. By contrast, wind noises are generated chiefly by instances of turbulence at the microphone openings. The microphone signals caused by wind of a number of microphones therefore are uncorrelated to a high degree. This difference is exploited advantageously for the purpose of detecting wind noises.
[0011] In an embodiment of the inventive method, in order to determine the correlation of microphone signals of different microphones, the microphone signals are subtracted from one another. The higher the degree of correlation between the microphone signals, the lower the result of the subtraction will be, on average. The values which are obtained on average by subtracting two microphone signals therefore constitute a measure of the correlation of the microphone signals. A simple smoothing can be carried out in this case as a simple way of averaging the result of the subtraction. This can be implemented, for example, by low pass filtering. In order to decide whether the microphone signals constitute wind noises, the result of the subtraction, preferably after smoothing, is compared with a threshold value. If the smoothed signal overshoots the threshold value, wind noises are deemed to be present. It is therefore possible to initiate signal processing measures yet to be explained. If the threshold value is not reached, there is no need for measures to reduce wind noises.
[0012] In order to avoid frequently switching the status of the signal processing unit, in an embodiment of the method of the invention, measures for reducing wind noises are not activated or deactivated until the threshold value is continuously overshot, respectively, or undershot for a specific period of time.
[0013] Furthermore, in another embodiment of the inventive method, two threshold values are determined which must be continuously overshot or undershot for a specific period of time in order to switch the signal processing unit. This prevents frequent switching of the signal processing unit of the hearing aid in the event of wind noises which are just on the threshold of detection as such. The two threshold values therefore form a type of hysteresis in the detection of wind noises.
[0014] In order to determine the correlation between two or more signals, in addition to the above-described method, still further methods are known which can be used within the scope of the invention to determine the correlation between microphone output signals. However, the above-described method constitutes a version which is particularly simple to implement.
[0015] If wind noises have been established by an analysis of the microphone signals, suitable measures are to be taken in the processing of the microphone signals such that the wind noises are reduced. Examples of such measures are outlined below:
[0016] A suitable measure for suppressing wind noises is to switch microphone system of the hearing aid from a directional model to an omni-directional mode. Specifically, directional microphone systems react more sensitively to wind than non-directional microphone systems. Certainly, directional action of the hearing aid is worsened by this measure, but the wind noises nevertheless are reduced.
[0017] Another measure for reducing detected wind noises is to filter the microphone signals. Use is made for this purpose of the fact that the disturbing noises caused by wind are situated predominantly in the low frequency band. Low frequencies can be damped by appropriate high pass filtering, and the wind noises thus can be effectively suppressed. The hearing aid is therefore put into a type of “tweeter operating mode”, in which, essentially, only higher-frequency signal components of the microphone signals are further processed and amplified.
[0018] A further measure as a reaction to detected wind noises is to adapt the acting times of the AGC (Automatic Gain Control). Since wind noises are very different as regards both the temporal sequence and the loudness level, these constitute a significant problem in automatic control processes within the signal processing of a hearing aid such as, for example, the Automatic Gain Control (AGC). It is therefore expedient to select time constants which are as long as possible in the corresponding acting times. A relatively long response and decay time of AGC can therefore be set as reaction to detected wind noises.
[0019] A further measure is implemented in the further processing, whereby similar only signal components of the output signals of at least two microphones are further processed for reducing detected wind noises. Only signal components of output signals which emanate from one microphone are filtered out. The filtering can be performed, for example, by means of a subtraction filter. As in the above-described method for detecting wind noises, the invention also takes advantage in this case of the fact that the signal components caused by wind in microphone output signals are largely uncorrelated and therefore do not emanate in the same form from any further microphone. If only those signal components are further processed which essentially emanate in a similar way from a number of microphones, the wind noises are largely eliminated.
[0020] In addition to the above-identified individual measures for reducing wind noises, arbitrary combinations of these measures can be used in accordance with the invention. These also can vary; depending on the frequency and loudness level of the wind noises.
[0021] The invention can be employed in the case of all current types of hearing aids such as, for example, in hearing aids worn behind the ear, in hearing aids worn in the ear, in implantable hearing aids or in pocket aids. Electroacoustic transducers come into consideration as input transducers, while electromechanical, electromagnetic or electric transducers (for example for directly stimulating hearing cells) also come into consideration as output transducers. Furthermore, a hearing aid system formed by a number of aids, such as a hearing aid system with two hearing aids worn on the head for the purpose of binaural supply, also can be used. The microphone signals which are analyzed in order to detect wind noises then also can emanate from different aids.
[0022] Furthermore, the measures for reducing detected wind noises are not limited to the variation of parameters of the signal processing unit. Thus, for example, as reactions to detected wind noises it is also possible to switch off microphones, to vary the cross section of sound inlets of microphones, or to open or close sound inlets of microphones.
DESCRIPTION OF THE DRAWINGS
[0023] [0023]FIG. 1 is a schematic block diagram of a hearing aid in which wind noises are detected and reduced, constructed and operating in accordance with the invention.
[0024] [0024]FIG. 2 shows an embodiment of the inventive method for detecting wind noises in the form of a flowchart,
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] [0025]FIG. 1 shows schematically in a hearing aid the signal processing for detecting and reducing wind noises. The hearing aid has a number of microphones M 1 , M 2 , . . . , MN for converting acoustic signals into electric signals, a signal processing unit SV and an earphone H for converting electric signals into acoustic signals. Two of the microphone signals S 1 , S 2 are tapped and fed to a difference element 1 . The absolute value of the difference between the output signals S 1 , S 2 of the microphones M 1 and M 2 is formed in the difference element 1 . The difference signal is fed for the purpose of averaging to a low pass filter 2 , illustrated in FIG. 1 by the typical step response of a low pass filter. The low pass filter 2 causes smoothing of the difference signal. In the further course of the signal the smoothed signal is compared to two threshold values in the comparing element 3 . Wind noises are deemed to be present if the smoothed signal overshoots a threshold value T 1 . Wind noises are deemed not to be present if the smoothed signal undershoots a threshold value T 2 . In the event of the presence of wind noises, the signal processing unit SV of the hearing aid automatically takes measures to reduce these wind noises. If the smoothed signal is situated between the two threshold values T 1 and T 2 , the previous state of the hearing aid is maintained, i.e. if measures to reduce wind noises are currently active, these remain active, while if no measures for reducing wind noises are currently active, none are activated for the moment.
[0026] The hearing aid can react to detected wind noises in multiple ways shown by example below, the automatic control being performed by means of the signal processing unit SV:
[0027] In a first measure 1 for reducing wind noises in the hearing aid in accordance with the exemplary embodiment with the exception of the microphones M 1 , M 2 required for detecting wind noises, the microphones M 3 , M 4 . . . , MN are switched off. This is illustrated graphically in FIG. 1 by the symbol 4 , which shows an interrupted microphone signal path.
[0028] A further measure is to vary the directional characteristic of the hearing aid. This option is based on the finding that directional microphone systems react more sensitively to wind than omnidirectional microphone systems do. This measure is illustrated in FIG. 1 by means of the directional characteristics of an omnidirectional microphone in the form of a circle in accordance with symbol 5 .
[0029] Furthermore, the noises caused by wind are situated predominantly in the low frequency, audible frequency band. Consequently, another measure for reducing noises caused by wind is high pass filtering. FIG. 1 shows, for this purpose, in symbol 6 the typical step response of a high pass filter.
[0030] In hearing aids, disturbances caused by wind in a secondary fashion can occur in addition to the disturbances caused in a primary fashion in the form of wind noises. Such disturbances relate, in particular, to automatically proceeding control and adaptation processes of the signal processing of the hearing aid. AGC (Automatic Gain Control) may be named for this by way of example. Because of the output signals of the microphones, this automatic gain control tries to cause operation of a situation-dependent setting of the loudness level control of the hearing aid, in particular reduction of the gain in the case of very loud input levels. Since wind noises differ strongly from one another with reference to their loudness level and their duration, and the period of time between successive wind noises can vary strongly, because of the wind noises the internal AGC of the hearing aid will change the loudness level setting of the hearing aid very frequently. This leads to a “pumping effect” which is unpleasant to the wearer of a hearing aid. The response and delay times of the AGC are lengthened in the event of detected wind noises as a measure against this effect. The reaction times of the AGC are slowed down thereby. This is illustrated in FIG. 1 by the symbol 7 which represents the response and delay time of the AGC.
[0031] A further measure for reducing detected wind noises is the application of a subtraction filter. Such a subtraction filter ensures that, of the signal components of the output signals of a number of microphones, only those signal components which emanate equally from all these microphones are further processed and fed to the earphone H. Uncorrelated wind noises which emanate from only one microphone in each case are suppressed. The graphic illustration of this is represented by the symbol 8 in FIG. 1, which shows a difference element, and thus a substantial constituent of a subtraction filter.
[0032] Measures of a mechanical nature are also conceivable in addition to the previously described measures, which chiefly relate to signal processing. Thus, sound channels to the microphones can be automatically narrowed or closed, or wind shields can be flapped open or aligned in front of the microphone openings. These measures are illustrated in FIG. 1 by the symbol 9 , which shows a sound channel with a motor-actuated flap.
[0033] In the event of detected wind noises, in the hearing aid in accordance with the invention the above-described measures can be carried out for the purpose of reducing the wind noises individually or in an arbitrary combination, including as a function of the level and frequency of the wind noises occurring.
[0034] [0034]FIG. 2 shows a flowchart of the signal processing of a hearing aid for the purpose of detecting wind noises. After the hearing aid is switched on (start), it is firstly transferred into a state Z 1 . The signal processing remains in this state until the averaged difference signal |{overscore (s 1 −s 2 )}|, corrected for sign, of two microphone signals S 1 , S 2 undershoots a threshold value T 2 . If the difference signal overshoots the threshold value T 2 , the signal processing is transferred into a state Z 2 . The signal processing remains in this state until the difference signal undershoots a threshold value T 1 . If the difference signal overshoots the threshold value T1, the signal processing passes into the state Z 3 . It remains in the state Z 3 until the difference signal overshoots the threshold value T 2 . It is transferred into the output state Z 1 again in the event of undershooting the threshold value T 2 .
[0035] In the flowchart in accordance with FIG. 2, the states Z 1 and Z 2 signify “no wind” (({overscore (W)})), and the state Z 3 signifies “wind” (W). In state Z 3 (“wind”), suitable measures, for example those named above, can be taken to reduce the detected wind noises.
[0036] In the event of the detection of wind noises, the indicated cycle of signal processing with the two threshold values T 1 and T 2 results in a hysteresis which prevents very frequent switching over of the hearing aid between the operating states of “wind” and “no wind”. A further measure for preventing frequent switching over is formed by the invention in that the states Z 1 to Z 3 are changed only when the difference signal continuously overshoots or undershoots the threshold values for a specific period of time which can be set. | In a method for operating a hearing aid or hearing aid system, and a hearing aid or hearing aid system, wind noises are detected by analyzing the output signals of at least two microphones. If wind noises are present, the signal processing unit of the hearing aid or hearing aid system and/or the signal paths of microphones are adapted in order to reduce such noises. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of U.S. patent application Ser. No. 11/620,928, now U.S. Pat. No. 7,789,171 entitled “Device and Method for Measuring a Property in a Downhole Apparatus,”, filed on Jan. 8, 2007.
BACKGROUND
The present invention relates to measuring a property in a downhole apparatus.
More particularly, the various embodiments of the invention are directed to measuring incremental torque between sensors and using this information to improve drilling practices.
In downhole drilling, it has become commonplace to include in the downhole apparatus one or more logging tools. This may include any number of logging-while-drilling (LWD) and measuring-while-drilling (MWD) tools, which generally have mechanical apparatuses and electrical circuits to perform specific tasks.
As those skilled in the art know, the operating environment experienced by the logging tools is very harsh. By virtue of the tools being part of the downhole apparatus, the tools experience relatively high accelerating forces due to vibration of a drill bit cutting through downhole formations. Some parameters can be measured downhole and transmitted to the surface, thereby providing a feedback system, which improves drilling efficiency and downhole tool reliability. The torque and vibration experienced may exceed specified ranges for some components that make up the downhole apparatus, thus reducing the life span of any particular electrical or mechanical device.
These problems benefit from a method for updating and/or measuring the downhole torque on the downhole apparatus and transmitting this information to the surface to improve real-time operations. A common method currently used today for measuring downhole torque utilizes strain gauges. These devices require a lengthy and complex calibration process in order for them to properly measure the torque applied to the downhole devices. Even with this calibration process these gauges drift over time causing error with the measurements and must be periodically recalibrated.
SUMMARY
The present invention provides a method and device for measuring incremental torque in a downhole apparatus.
In one embodiment of the present invention, the device comprises a first sensor and a second sensor attached to the downhole apparatus, separated by a distance and an angle. Also included is a logic circuit, which may compute the torque over the distance, based on the distance, the angle, and physical properties of the downhole apparatus.
In another embodiment of the present invention, the device also comprises additional sensors, such that the torque is calculable over various distances.
In yet another embodiment of the present invention, the sensors are magnetometers that measure the angle based on azimuths.
In a further embodiment of the present invention, the method comprises the steps of applying torque, determining the orientation of sensors, determining the distance between the sensors, and using a logic circuit, either on the surface or downhole, to determine the torque. This may occur after a step of aligning the sensors.
In another embodiment, the method does not include the step of aligning the sensors. Instead, the method includes an additional step of determining the directions of the sensors prior to the application of the torque.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a downhole apparatus in accordance with one embodiment of the invention.
FIG. 2 is a side view of the downhole apparatus of FIG. 1 , after application of an incremental torque.
FIG. 3 is a perspective view of the downhole apparatus of FIG. 2 , showing only the portion between lines AA and BB.
FIG. 4 is a perspective view of the downhole apparatus of FIG. 1 , showing only the portion between lines AA and BB.
FIGS. 5A and 5B are block diagrams of a logic circuit in accordance with one embodiment of the invention.
DETAILED DESCRIPTION
Referring to FIG. 1 , shown therein is a downhole apparatus 100 , having a first sensor 102 and a second sensor 202 disposed thereon. The downhole apparatus 100 may be a casing string, a pipe string, a logging tool, or anything else that may have a rotational force applied, causing it to experience an incremental torque T. As used herein, the term “incremental torque” refers to torque that is not present in an initial or base condition, the term “base torque” refers to torque that is present in the base condition, and “total torque” refers to the sum of the incremental torque and the base torque.
The downhole apparatus 100 typically has multiple components, which connect to one another by threaded connections. Frequently, the downhole apparatus 100 already includes the sensors 102 , 202 , such as magnetometers, which can provide information about their orientation in the drillstring. These sensors 102 , 202 commonly provide information to operators regarding the orientation of the downhole apparatus 100 . Additionally, the downhole apparatus 100 may have strain gauges (not shown), which are used to measure torque at the locations of the strain gauges. While torque measurements at a given location provide useful information, the strain gauges, which require calibration, may lose their calibration in the harsh conditions present in the downhole environment. The heat involved, in particular, may cause a need for frequent recalibration of the strain gauges. This is costly and time-consuming. The replacement of the strain gauge measurement with a method of measurement based on more stable sensors that are typically present in the system would improve the accuracy and greatly minimize calibration costs. By employing devices already in the downhole apparatus, no additional components would be needed to measure torque. This would result in the downhole apparatus 100 having fewer components, saving time and money and allowing for more accuracy in readings. Additionally, the strain gauge only takes measurements at a single, finite location.
The sensors 102 , 202 may threadedly attach to the downhole apparatus 100 or they may otherwise attach to the downhole apparatus 100 . The sensors 102 , 202 may both be within a single section, the sensors 102 , 202 may be in multiple sections, or the sensors 102 , 202 may be distributed along the string.
Regardless of the manner of attachment, the first sensor 102 and the second sensor 202 are separated by a distance L (shown in FIGS. 3 and 4 ). Before incremental torque T is applied, the sensors 102 , 202 may initially be aligned azimuthally (not shown), or they may be offset from one another at an initial or base angle φ b (shown in FIG. 4 ). When the sensors 102 and 202 azimuthally align, the base angle φ b will separate them.
FIG. 2 shows the downhole apparatus 100 , with the sensors 102 , 202 separated by the distance L after the incremental torque T has been applied. This distance L typically remains substantially unchanged in the presence of torque. However, the sensors 102 , 202 of FIG. 2 have experienced a relative rotational movement about the downhole apparatus 100 due to the incremental torque T. The incremental torque T is the result of a rotational force applied to the apparatus 100 , such as might be present in a drilling operation. The incremental torque T causes the sensors 102 , 202 to be offset from one another by a resulting angle φ r (shown in FIG. 3 ). The direction and the magnitude of the movement and the resulting angle φ r will vary, depending on the incremental torque T and other factors as described below.
Referring now to FIG. 3 , the incremental torque T can be calculated based on readings from at least the first sensor 102 and the second sensor 202 attached to the downhole apparatus 100 . The sensors 102 , 202 attach to the downhole apparatus 100 , and simultaneously measure directions of a first resulting radial vector 104 r , which corresponds to the first sensor 102 , and a second resulting radial vector 204 r , which corresponds to the second sensor 202 . The incremental torque T is calculated using the equation T=(φ r −φ b )GJ/L, which takes into account the change in position of the sensors 102 , 202 resulting from the incremental torque T. This change in position is measured by the change in angle between the sensors 102 , 202 , which is represented by the difference between the resulting angle φ r , and the base angle φ b . This is represented as “(φ r −φ b )” in the equation. The equation also uses the distance L, the polar moment of inertia J, and the material makeup G of the downhole apparatus 100 between the sensors 102 and 202 .
The present invention calculates the incremental torque T in the downhole apparatus 100 using the sensors 102 , 202 , which may already be present in the downhole apparatus 100 for another purpose. Alternatively, the sensors 102 , 202 may be present in the downhole apparatus 100 for the sole purpose of measuring incremental torque T. Each sensor 102 , 202 provides an indication of which direction that sensor 102 , 202 is facing relative to the downhole apparatus 100 after incremental torque T has been applied. A first resulting vector 104 r and a second resulting vector 204 r represent these directions. The resulting vectors 104 r , 204 r radiate from a centerline 106 of the downhole apparatus 100 . The centerline 106 is only an imaginary reference for the resulting vectors 104 r , 204 r . The centerline 106 need not be vertical, or even straight. In fact, the centerline 106 may be horizontal, or it may curve at any angle.
The first resulting vector 104 r extends perpendicularly from the centerline 106 to the first sensor 102 and the second resulting vector 204 r extends perpendicularly from the centerline 106 to the second sensor 202 . In one embodiment, the direction of the resulting vectors 104 r , 204 r translate to azimuths, which may represent directions defined by the projection of the Earth's magnetic field on a plane orthogonal to the drill string axis. The azimuths are not necessarily limited to magnetic azimuths, but may be an angle around the borehole that indicates the direction of maximum sensitivity of the sensors 102 , 202 . Likewise, vectors refer to the representative components of the constant vectors and are representative relative to the coordinate system of the tool.
The application of force resulting in the incremental torque T causes the direction of the respective sensors 102 , 202 to change. However, the incremental torque T is not the only possible cause of a change in the direction of the sensors 102 , 202 . The direction of the sensors 102 , 202 also change when the downhole apparatus 100 is rotated, even when no torque is present, i.e., when the downhole apparatus 100 rotates freely, with no constraints.
As shown in FIG. 3 , it is useful to compare the direction of the first resulting vector 104 r to the direction of the second resulting vector 204 r , in order to determine the incremental torque T. This eliminates any influence caused by directional change resulting from free rotation, which would cause changes in the directions of the resulting vectors 104 r , 204 r , but which would not cause a change in the angle φ r between them. In this manner, only directional change caused by the incremental torque T is measured.
Referring now to FIGS. 3 and 4 , incremental torque T may be determined based on directional readings of the first sensor 102 and the second sensor 202 . In this determination, the following equation, as stated above, is useful: T=(φ r −φ b )GJ/L. In this equation, T is the incremental torque. φ r is a resulting angle formed between the first resulting vector 104 r and the second resulting vector 204 r. φ b is a base angle formed between a first base vector 104 b and a second base vector 204 b . G is the modulus of rigidity of the portion of the downhole apparatus 100 that lies between the sensors 102 and 202 . J is the polar moment of inertia of the portion of the downhole apparatus 100 that lies between the sensors 102 and 202 . L is the length of the portion of the downhole apparatus 100 that lies between the sensors 102 and 202 and represents the distance between the sensors 102 and 202 . L remains substantially constant when incremental torque T is applied.
The incremental torque T may have any units common to torque measurements, such as, but not limited to, Lb-in. The angles φ r , φ b may have radians as units. However, any angular units can be used. The modulus of rigidity G is a constant that is readily ascertainable, based on the material used. Modulus of rigidity G may have units of lb/in 2 or any other suitable substitute. The polar moment of inertia J is a function of the cross sectional shape of the downhole apparatus 100 . The polar moment of inertia J may have units of in 4 or any other suitable substitute. For a uniform tubular cross section, the polar moment of inertia J is equal to π(d o 4 −d i 4 )/32, where d o is the outer diameter and d i is the inner diameter of the tubular. However, the polar moment of inertia J is also readily ascertainable for a variable tubular cross section, such as that of a stabilizer. One skilled in the art could easily calculate polar moment of inertia J for a variety of shapes, as polar moment of inertia J is calculable with well-known formulas.
A logic circuit 502 , illustrated in FIGS. 5A and 5B , may be provided to perform the calculations. The logic circuit 502 includes a processor 504 , which serves as a controller processor. This controller processor 504 communicatedly connects 506 with a number of sensors 508 a , 508 b , 508 c in the vicinity of the controller processor 504 downhole. Each sensor 508 may be a smart sensor, a microcontroller, or any other type of sensor known in the art. Each sensor 508 may contain its own processor coupled to a sensor, such as one of the sensors 102 , 202 , and may collect data from, or provide data to, the sensors. The sensor 508 may collect data from the associated sensors to transmit to the controller processor 504 , which in turn gathers all of the data from the sensors 508 a , 508 b , 508 c , and transmits it to the surface for processing as described herein. Alternatively, the controller processor 504 may perform the processing.
The controller 504 and sensors 508 may be distributed among elements of the drill string 510 a , 510 b , 510 c , 510 d and 510 e , as shown in FIG. 5B .
It may be desirable to measure the incremental torque T relative to a prior, known condition. In this instance, the logic circuit 502 compares base readings with new readings obtained after a rotational force is applied. The first base vector 104 b represents the position of the first sensor 102 before rotational force is applied, and the first resulting vector 104 r represents the position of the first sensor 102 after application of the rotational force. Likewise, the second base vector 204 b represents the position of the second sensor 202 before rotational force is applied, and the second resulting vector 204 r represents the position of the second sensor 202 after application of the rotational force. Similarly, the base angle φ b represents the angle between the first base vector 104 b and the second base vector 204 b , and the resulting angle φ r represents the angle between the first resulting vector 104 r and the second resulting vector 204 r.
However, these various base readings are not always required. For example, the resulting angle φ r between the first resulting vector 104 r and the second resulting vector 204 r may be enough to determine the incremental torque T. This condition would occur when sensors 102 , 202 and thus the base vectors 104 b , 204 b align, or face in the same direction, prior to the application of rotational force. This causes the base angle φ b to be equal to zero, such that the later measured resulting angle φ r will only be associated with the incremental torque T between the first sensor 102 and the second sensor 202 . Nonetheless, it is not always practical or desirable to set the sensors 102 , 202 in the same direction while refraining from applying a rotational force. The base angle φ b may also be measured prior to tripping into the borehole or the base angle φ b may be measured at a time when the tool is stationary.
When the first base vector 104 b and the second base vector 204 b do not align, the incremental torque T may still be easily calculated. This is particularly useful when already present components of the downhole apparatus 100 function as the sensors 102 , 202 . For example, magnetometers are commonly present on the downhole apparatus 100 and can provide information useful for calculating incremental torque T. The ability to calculate the incremental torque T without the need for alteration of existing components saves both time and money.
In this instance, the base angle φ b between the first base vector 104 b and the second base vector 204 b is calculated. This may occur at any time during the downhole operation, such as when the drilling operation is stopped for pipe connections, maintenance or retooling. After recordation of the base angle φ b , rotational force is applied, causing the resulting angle φ r between the first resulting vector 104 r and the second resulting vector 204 r . In order to determine the incremental torque T, the base angle φ b is subtracted from the resulting angle φ r in the equation above.
As discussed above, the incremental torque T can be calculated without first aligning the sensors 102 , 202 , or incremental torque T can be calculated by comparing the base angle φ b with the resulting angle φ r . Additionally, the incremental torque T can be calculated when the base conditions additionally include an already present known base torque Tb. This allows the incremental torque T to be calculated without stopping the operation, so long as the base torque Tb is known. The known base torque Tb may be zero (representing no torque at all), or it may be any other known measurement. If a total torque T tot is required, it can be easily calculated by summing the base torque Tb and the incremental torque T. When there is no base torque Tb, the total torque T tot will be equal to the incremental torque T. It should be noted that the quantity (φ r −φ b ) indicates the movement of the sensors 102 , 202 from a position indicated by base vectors 104 b , 204 b to a position indicated by resulting vectors 104 r , 204 r as a result of the incremental torque T. Therefore, one of ordinary skill in the art will be able to modify this equation to accommodate conditions resulting in negative numbers or any other special circumstances.
In this manner, the incremental torque T can be determined between any two sensors 102 , 202 , so long as either of two conditions are met: (1) the sensors 102 , 202 are aligned such that their respective base vectors 104 b , 204 b have the same direction, or (2) the base angle φ b corresponding to a known base torque Tb is recorded.
Each sensor 102 , 202 may have one or more magnetometers, or any other device capable of measuring the resulting vectors 104 r , 204 r or the base vectors 104 b , 204 b . Since magnetometers lose accuracy when the field of measurement is nulled, a single magnetometer may not perform optimally in, for example, a direction of drilling that would cause the sensing field to be minimized. In this instance, multiple devices may be included within the sensors 102 , 202 . For example, each sensor 102 , 202 may include a magnetometer, a gyro device, a gravity device, or any other type of device that measures orientation. These measurements may be taken based on magnetic fields, gravity, or the earth's spin axis. This may allow for directional readings in any position. Multiple devices may also be used to check the measurements of one another. Additionally, the sensors 102 , 202 may indicate the quantity (φ r −φ b ) by any method, either with or without the use of vectors 104 b , 104 r , 204 b , 204 r radiating from the centerline 106 . For example, the sensors 102 , 202 may indicate relative position by sonic ranging, north seeking gyros, multiple directional instruments, or any other means capable of communicating the position of the first sensor 102 relative to the second sensor 202 . The sensors 102 , 202 may attach to the downhole apparatus 100 in any position. Since the quantity (φ r −φ b ) can be measured at any point outside the centerline 106 , the sensors 102 , 202 may be on an inside surface, an outside surface, or within a wall of the downhole apparatus 100 . Additionally, the sensors 102 , 202 may threadedly attach at threaded ends of a section, or the sensors 102 , 202 may be an integral part of the downhole apparatus 100 .
Each sensor 102 , 202 may provide a signal to indicate its position and orientation. This may be done via the logic circuit 502 . The logic circuit 502 may then calculate the incremental torque T between any two sensors 102 , 202 . This calculation may be an average reading over a period of time, or it may be at a single measured point in time. Since the incremental torque T may vary along the length, it may be desirable to have additional sensors (not shown). In the event that additional sensors are used, multiple sectional incremental torque readings are calculable. This is useful during drilling operations. Due to the length of the typical downhole apparatus 100 , it is common that the incremental torque T varies along the length. This may occur, for example, when a portion of the downhole apparatus 100 rubs against a formation, or otherwise experiences binding. This may cause a very low incremental torque in one portion of the downhole apparatus 100 , while causing another portion of the same downhole apparatus 100 to experience very high incremental torque. As one of ordinary skill in the art can appreciate, this is undesirable for a number of reasons, including bit stick/slip.
When more than two sensors are used, the methods described above may be used between any two sensors, resulting in a number of incremental torque T readings that exceeds the number of sensors. For example, four sensors could give six readings. Say these sensors are called A, B, C, and D (not shown). Readings are calculable between A and B; A and C; A and D; B and C; B and D; C and D. While some of these readings would appear redundant, these multiple readings are useful to check or calibrate the incremental torque T readings during operation, without the need to cease operations.
During a downhole operation, many measurements may be taken and averaged or otherwise analyzed to find the incremental torque T. These measurements may reflect a constant incremental torque, or these measurements may reflect a changing incremental torque. One skilled in the art will recognize that the number of measurements necessary for statistical accuracy may vary, depending on the actual conditions.
Likewise, measurements may be used to determine other data. For example, tortuosity may be measured by taking multiple shots over time, giving the shape of the borehole. This can be used to build a model for drilling efficiency and can assist in getting the casing into the borehole. Additionally, monitoring tortuosity may allow the driller to straighten out the borehole. In another example, dogleg severity, or the limit of angle of deflection, can be determined using multiple samples over time to provide information on stresses that the drillstring is experiencing. This would allow for a determination as to whether the tool is being pushed beyond recommended limits. Additionally, bending can be measured with a device, such as an accelerometer. The bending measurement may be a one-time sample. While a bending radius can be inferred from any bending measurement, samples over time may give a more accurate bending radius. Other examples of measurements include stick slip, sticking, and the like.
The sensors 102 , 202 can also be useful in determining problems, such as, but not limited to inelastic deformation, and unscrewing. For instance, if the sensors 102 , 202 are separated across one or more joints, and the offset between the sensors 102 , 202 changes significantly, there is a high likelihood that something has gone wrong. Additionally, the sensors 102 , 202 may be used on a deliberately bent assembly to ensure that the bend is still proper, or for other purposes. The sensors 102 , 202 may also be used with motors and rotary steerables to validate that the build angle is matching the well plan.
In addition to measuring changes in conditions, multiple samples may be used to correct noise in sampling. This may be done using e.g. a “burst” sample.
Measurements may be taken using differential change in measured magnetic tool face. For example, this may begin with the transformation from Earth coordinates to tool coordinates, where BN is the North component of the Earth's magnetic field, BV is the vertical component (and by definition, the East component is 0), and where Bx1, By1, and Bz1 are the respective x, y, and z components of the observed magnetic field at magnetometer 1 . Likewise Bx2, By2, and Bz2 are the respective x, y, and z components of the observed magnetic field at magnetometer 2 . ρ1 is the magnetic tool face at magnetometer 1 , and ρ2 is the magnetic tool face at magnetometer 2 .
In general:
(
Bx
By
Bz
)
=
(
Cos
[
θ
]
Cos
[
ϕ
]
Cos
[
ψ
]
-
Sin
[
ϕ
]
Sin
[
ψ
]
Cos
[
ψ
]
Sin
[
ϕ
]
+
Cos
[
θ
]
Cos
[
ϕ
]
Sin
[
ψ
]
-
Cos
[
θ
]
Cos
[
ψ
]
Sin
[
ϕ
]
-
Cos
[
ϕ
]
Sin
[
ψ
]
Cos
[
ϕ
]
Cos
[
ψ
]
-
Cos
[
θ
]
Sin
[
ϕ
]
Sin
[
ψ
]
Cos
[
ψ
]
Sin
[
ϕ
]
Sin
[
θ
]
Sin
[
ψ
]
-
Cos
[
ϕ
]
Sin
[
θ
Sin
[
θ
]
Sin
[
ϕ
]
Cos
[
θ
]
)
·
(
BN
0
BV
)
From
which
(
Bx
By
Bz
)
=
(
-
BV
Cos
[
ϕ
]
Sin
[
θ
]
+
BN
(
Cos
[
θ
]
Cos
[
ϕ
]
Cos
[
ψ
]
-
Sin
[
ϕ
]
Sin
[
ψ
]
)
BV
Sin
[
θ
]
Sin
[
ϕ
]
+
BN
(
-
Cos
[
θ
]
Cos
[
ψ
]
Sin
[
ϕ
]
-
Cos
[
ϕ
]
Sin
[
ψ
]
)
BV
Cos
[
θ
]
+
BN
Cos
[
ψ
]
Sin
[
θ
]
)
The formula below may be used to calculate two magnetic tool face values. While this may be defined in any number of ways, the choice should not significantly affect the result.
φ=ArcTan [− Bx,By]
Where arctan is the four quadrant arctan, with quadrant information derived from the algebraic signs of the x and y terms.
So that:
φ1=ArcTan [ BV Cos [φ1] Sin [θ1 ]−BN (Cos [θ1] Cos [φ1] Cos [ψ1]+Sin [φ1] Sin [ψ1]), BV Sin [θ1] Sin [φ1 ]−BN (−Cos [θ1] Cos [ψ2] Sin [φ1]−Cos [φ1] Sin [ψ1])]
φ2=ArcTan [ BV Cos [φ2] Sin [θ2 ]−BN (Cos [θ2] Cos [φ2] Cos [ψ2]+Sin [φ2] Sin [ψ2]), BV Sin [θ2] Sin [φ2 ]−BN (−Cos [θ2] Cos [ψ2] Sin [φ2]−Cos [φ2] Sin [ψ2])]
Defining the dip angle as D:
BV
=
Bt
*
Sin
[
??
]
BN
=
Bt
*
Cos
[
??
]
??1
=
ArcTan
[
Cos
(
θ1
]
Cos
[
ψ1
]
-
Sin
[
θ1
]
Tan
[
??
]
Sin
[
ψ1
]
+
Tan
[
ϕ1
]
,
1
-
(
-
Cos
(
θ1
]
Cos
[
ψ1
]
+
Sin
[
θ1
]
Tan
[
??
]
)
Sin
[
ψ1
]
Tan
[
ϕ1
]
]
Let
:
Tan
[
α1
]
=
Cos
(
θ1
]
Cos
[
ψ1
]
-
Sin
[
θ1
]
Tan
[
??
]
Sin
[
ψ1
]
So
that
:
??1
=
ArcTan
[
Tan
[
α1
]
+
Tan
[
ϕ1
]
,
1
-
Tan
[
α1
]
Tan
[
ϕ1
]
]
??1
=
ϕ1
+
α1
Similarly
:
??2
=
ϕ2
+
α2
Where
:
Tan
[
α2
]
=
Cos
[
θ2
]
Cos
[
ψ2
]
-
Sin
[
θ2
]
Tan
[
??
]
Sin
[
ψ2
]
The quantity of interest is:
φ2−φ1=(φ2−φ1)+(α2−α1)
This equation illustrates an important point: In order to calculate a specific torque (i.e. a torque about the drillstring axis, or a bending moment), it is sometimes necessary to decouple the available measurements. The equations given here indicate when this is necessary in the case of measurements made with magnetometers and inclinators, and they show how the decoupling is effected. This is further illustrated in cases 1-4 below. If other types of sensors are used, similar equations can be derived, as will be evident to one skilled in the art.
Case 1
When there is constant inclination and azimuth, only the tool face may vary. In this case, α2=α1, and the change in magnetic tool face equals the change in gravitational tool face. If there is a change in inclination or azimuth, a change in dip is not expected, except via noise.
Case 2
When there is constant azimuth, the inclination and tool face may vary. In this case, working first with inclination, suppose θ2=θ1+δθ, and dropping second order terms:
Tan
[
α2
]
=
Cos
[
θ1
]
Cos
[
ψ2
]
-
Sin
[
θ1
]
Tan
[
??
]
-
δθ
(
-
Cos
[
ψ2
]
Sin
[
θ1
]
-
Cos
[
θ1
]
Tan
[
??
]
)
Sin
[
ψ2
]
So
that
:
Tan
[
α2
-
α1
]
=
Tan
[
α2
]
-
Tan
[
α1
]
1
+
Tan
[
α2
]
*
Tan
[
α1
]
Tan
[
α2
]
-
Tan
[
α1
]
=
Cos
[
θ1
]
Cos
[
ψ2
]
-
Sin
[
θ1
]
Tan
[
??
]
+
δθ
(
-
Cos
[
ψ2
]
Sin
[
θ1
]
-
Cos
[
θ1
]
Tan
[
??
]
)
Sin
[
ψ2
]
-
Cos
[
θ1
]
Cos
[
ψ1
]
-
Sin
[
θ1
]
Tan
[
??
]
Sin
[
ψ1
]
But, the assumption in this case is that ψ2=ψ1, so
Tan [α2−α1]=−δθ(Cot [ψ1] Sin [θ1]+Cos [θ1] Csc [ψ1] Tan [ D ])
Or, to the small angle approximation:
α2−α1=−δθ(Cot [ψ1] Sin [θ1]+Cos [θ1] Csc [ψ1] Tan [ D ])
There is, therefore, the potential that small changes in inclination will, at small azimuths, make a significant contribution to ρ2−ρ1.
Case 3
When there is constant inclination, the azimuth and tool face may vary. In this case, θ2=θ1, but ψ2=1+δψ. With the same type of reasoning, it can be shown that in the differential limit:
α2−α1=−δψ Csc [ψ1](Cos [θ1] Csc [ψ1]−Cot [ψ1] Sin [θ1] Tan [ D ])
With sin [θ1]=cos [D], and cos [θ1]=sin [D], then:
α2−α1=−δψ Csc [ψ1](Sin [ D ] Csc [ψ1]−Cot [ψ1] Sin [ D ])
So that as ψ1→0, i.e. as the trajectory aligns with the Earth's magnetic field, this term vanishes. However, the magnetic tool face is not defined under this condition.
Case 4
When inclination azimuth and tool face vary, in the small angle approximation, the previous results can be combined to obtain:
α2−α1=−δθ(Cot [ψ1] Sin [θ1]−Cos [θ1] Csc [ψ1] Tan [ D ])−δψ Csc [ψ1](Sin [ D ] Csc [ψ1]−Cot [ψ1] Sin [ D ])
Or:
φ2−φ1=δφ−δθ(Cot [ψ1] Sin [θ1]−Cos [θ1] Csc [ψ1] Tan [ D ])−δψ Csc [ψ1](Sin [ D ] Csc [ψ1]−Cot [ψ1] Sin [ D ])
Note that torque is preferably inferred using δφ, not δρ=ρ2−ρ1.
Therefore, if a lot of change is expected in inclination and/or azimuth, in addition to the change in magnetic tool face, the inclination and azimuth is desirably measured at both points where the magnetic tool face is measured. It may be advantageous under these conditions to use the gravitational readings instead of the magnetic field readings.
Measurements may also be taken using differential change in gravitational tool face. Because gravity simply points down, the transformation of the gravitational field from NEV to tool coordinates is much simpler. gx1, gy1, and gz1 are the respective x, y, and z components of the observed gravitational field at accelerometer 1 . Likewise gx2, gy2, and gz2 are the respective x, y, and z components of the observed gravitational field at accelerometer 2 . ρ1 is the magnetic tool face at magnetometer 1 , and ρ2 is the magnetic tool face at magnetometer 2 . φ1 is the gravitational tool face at accelerometer 1 and φ2 is the gravitational tool face at accelerometer 2 .
In general:
(
gx
gy
gz
)
=
(
Cos
[
θ
]
Cos
[
ϕ
]
Cos
[
ψ
]
-
Sin
[
ϕ
]
Sin
[
ψ
]
Cos
[
ψ
]
Sin
[
ϕ
]
+
Cos
[
θ
]
Cos
[
ϕ
]
Sin
[
ψ
]
-
Cos
[
ϕ
]
Sin
[
θ
-
Cos
[
θ
]
Cos
[
ψ
]
Sin
[
ϕ
]
-
Cos
[
ϕ
]
Sin
[
ψ
]
Cos
[
ϕ
]
Cos
[
ψ
]
-
Cos
[
θ
]
Sin
[
ϕ
]
Sin
[
ψ
]
Sin
[
θ
]
Sin
[
ϕ
]
Cos
[
ψ
]
Sin
[
ϕ
]
Sin
[
θ
]
Sin
[
ψ
]
Cos
[
θ
]
)
·
(
0
0
g
)
.
Where g is the magnitude of the gravitational field:
g
=
gx
2
+
gy
2
+
gz
2
(
gx
gy
gz
)
=
g
(
-
Sin
[
θ
]
Cos
[
ϕ
]
Sin
[
θ
]
Sin
[
ϕ
]
Cos
[
θ
]
)
Therefore, except when θ=0 or θ=π:
φ=ArcTan [− gx,gy]
And is independent of the inclination or the azimuth. Therefore, φ2−φ1 is independent of changes in the inclination or azimuth, so that changes in gravitational tool face can be used directly to measure torque.
Since gz is independent of the tool face, a bending moment can be measured using changes in the inclination. A change in inclination is reflected by a deflection in a vertical plane containing the well trajectory (at least locally).
In general, there will also be a second bending moment for deflections of the drillstring orthogonal to a vertical plane containing the well trajectory (locally). An azimuth change is associated with this deflection, but is not sufficient by itself to calculate die desired bending moment since the torque acts along the tool axis, whereas the azimuth change is defined as a rotation towards North.
Assuming there is no magnetic interference:
ψ=ArcTan [ Bx *Cos [φ]− By *Sin [φ])*Cos [θ]+ Bz *Sin [θ],−( Bx *Sin [φ]+ By *Cos [φ])]
The azimuth can often be calculated in the presence of magnetic interference, but the techniques used are considerably more complicated. A similar analysis can be carried out with them, but with considerable complexity. Adding suffixes 1 and 2 for measurements made at locations 1 and 2 gives:
ψ1=ArcTan [( Bx *Cos [φ1 ]−By 1*Sin [φ1])*Cos [θ1 ]+Bz 1*Sin [θ1],−( Bx 1*Sin [φ1 ]+By 1*Cos [φ1])]
ψ2=ArcTan [( Bx 2*Cos [φ2 ]−By 2*Sin [φ2])*Cos [θ2 ]+Bz 2*Sin [θ2],−( Bx 2*Sin [φ2 ]+By 2*Cos [φ2])]
The angular change δψ=ψ2−ψ1 could be used to define a bending moment, but it is desirable to equate this to a deflection of the drillstring in a direction generally perpendicular to a vertical plane tangent to the trajectory at either measurement point 1 or measurement point 2 . This deflection, called δζ, can be calculated considering that the change in azimuth is the projection of the sought deflection on the horizontal plane. Therefore, the desired angular deflection, assuming that the change in inclination between the two survey points is small compared to the inclination itself, is:
δζ
=
(
ψ2
-
ψ1
)
*
Sin
[
θ1
+
θ2
2
]
Therefore, the present invention is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the present invention. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. | A method and device for measuring a property, such as torque, includes a plurality of sensors, and a measuring device. The sensors attach to a downhole apparatus at a distance from one another. The sensors provide signals indicating their positions. A logic circuit may calculate an angle between the sensors. The logic circuit then calculates the property based on the angle, the distance between the sensors, and other known physical properties of the downhole apparatus. | 4 |
This invention relates to a draw-off device for drawing-off flexible goods, particularly textile goods, with a stepless adjustable draw-off tension, from a machine producing or processing the goods. It also relates to a circular knitting machine provided with such a device.
BACKGROUND OF THE INVENTION
Draw-off devices, also called take-down devices, of this kind are known especially in warp knitting machine (U.S. Pat. Nos. 2,649,811, 2,760,362) and comprise at least one take-down roller, a drive source and a transmission connecting the take-down roller and the drive source. The transmission is or comprises a V-belt transmission which includes a V-belt pulley formed as a control pulley, with two conical flanges, of which at least one is mounted so as to be axially movable, in order to alter the effective diameter of the V-belt pulley, a V-shaped belt at least partially wrapping round the V-belt pulley and a device for adjusting the take-down tension, by means of which a displacement of the movable flange can be effected through alteration of the tension in the V-belt. Such draw-off devices serve for stepless adjustment of the winding-up speed of a winding-up roller, at the same time however to adjust for different tensions in the goods taken down. The V-belt pulley there consists of two immovable conical flanges, between which an axially movable further flange which is conical on both sides is arranged. Two adjacent V-shaped sections thereby result for reception of a V-shaped belt in each, which belts centre between the movable and an associated fixed flange. The effective diameter of each section thus depends on the instantaneous axial position of the movable flange. This position can be affected by a displacement radially relative to the running direction of the two V-belts or by tilting the V-belt pulley, since the tension of one V-belt is thereby momentarily increased and the tension of the other V-belt is momentarily reduced. The inequality thereby created automatically results in corresponding displacement of the movable flange and corresponding alteration of the effective diameters of the two sections of the V-belt pulley. Accordingly the relative speeds of circulation of the two V-belts alter and the transmission ratio of the V-belt drive or the overall drive including the same alters.
The described V-belt drive is comparatively complex and sensitive. It further requires the use of a tilting or shift mechanism for the V-belt or control pulley as well as the use of two V-belts to compensate for the shifting or like displacement of the axis of the V-belt pulley. Both of these are not always desirable. The cited disadvantages can it is true be partially avoided by use of another known V-belt drive (FR 915 696, DE 88 00 999 U1, DE 3 213 950 A1, DE 3 601 825 A1) but with this a manual change in the diameter of the V-belt pulley is necessary with the take-down mechanism at rest, which is likewise troublesome and in most cases undesirable.
SUMMARY OF THE INVENTION
It is an object of this invention to design the take-down or draw-off device of the kind initially defined such that the drawbacks mentioned above can be avoided.
A further object of this invention is to provide a draw-off device which can work with only one V-belt.
Yet another object of this invention is to suggest a draw-off device of a comparatively simple construction.
Another object of this invention is to design the draw-off device such that it facilitates changing the draw-down tension with the V-belt pulley in operation.
These and other objects of the invention are solved with the draw-off device of this invention which is characterized in that the movable flange is biased by spring force in the direction of the other flange and in that the device for adjusting the take-down tension comprises at least one separate, adjustable tensioning roller for the V-belt.
The invention has the advantage that the axial spacing of all transmission components is always the same, regardless of the adjusted take-down force. To alter the take-down tension it is merely necessary to alter the position of the tensioning roller acting on the V-belt, which has no effect on the kinematics and geometry of the transmission as a whole. Moreover, a constructionally simpler design, cost-effective manufacture and fitting, high operating reliability and stepless, simple and reproducible adjustment and alteration of the take-down tension result. Apart from this, it is evident that the take-down device facilitates positive take-down of goods, without slip and takes down an amount of goods in fixed relationship to the instantaneous machine speed, independently of this speed.
Moreover it is evident that the expression "rope form" shall include all flexible goods, especially thread, web or tubular goods and textile fabrics, which can be taken down with take-down devices of the kind involved here.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be explained in more detail in conjunction with the accompanying drawings of an embodiment, in which:
FIG. 1 is a schematic side view of a circular knitting machine with a take-down device according to the invention;
FIG. 2 is a schematic front view of only the transmission according to the invention of the take-down device on a larger scale than FIG. 1; and
FIGS. 3 and 4 are further enlarged sections through the V-belt pulley of the transmission according to FIGS. 1 and 2 in two different positions.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 1 and 2 show a conventional circular knitting machine with a machine frame 1, a rotatable needle cylinder 2 and fixed locks 3. The needle cylinder 2 is fixed on a support ring 4, which is mounted rotatably in the machine frame 1, is formed at its outer periphery as a ring gear 5 and is coupled to a drive pinion 6, which can be rotated through a gearbox 7 by a drive motor 8.
Two carrier arms 9 are fixed to the support ting 4 and extend e.g. vertically downwards in the machine frame 1 and are fixed at their lower, free ends to two uprights 10,11. A draw-off or take-down device, is arranged between the uprights and rotates as a whole with the rotation of the support ring 4 and needle cylinder 2.
The take-down device normally includes two, preferably three positively driven take-down or draw-off rollers 14, 15 and 16. Their ends are rotatably mounted in the uprights 10,11 and form gaps (FIG. 2), between which goods, here tubular goods 17 produced in the circular knitting machine are taken down in the direction of the arrows v and w. The goods 17 normally pass hence to a winding up device, which is not shown here because it is of no significance to the invention and can even be omitted.
Circular knitting machines of the kind described are generally known to the man skilled in the art and do not therefore need to be explained in more detail.
The take-down rollers 14, 15 and 16 are driven by a drive source and a transmission arranged between them and the drive source. The drive source is here a stationary bevel gear 18 fixed to the bottom of the machine frame 1 (FIG. 1 ), on which a bevel gear 19 rolls with rotation of the support ring 4, and is fixed to one end of a shaft 20 rotatably mounted on the upright 11 and driving this shaft. The shaft 20 carries a sprocket 21 which is aligned with a sprocket 22 and is coupled thereto by a drive chain 23. The sprocket 22 is fitted on a shaft 24, to which is also fitted a V-belt pulley 25 formed as a control pulley and which is at least partially wrapped round by a V-belt 26. The V-belt also passes partially round a second, non-varying pulley 27. A pinion 28 is fixed to this and drives a gearwheel 33 through further gearwheels or pinions 29, 30, 31 and 32, the gearwheel 33 being fitted on the shaft carrying the take-down roller 15 and driving the take-down roller 15. This is coupled in a manner known per se to the two other take-down rollers 14 and 16 so that these are also driven. The parts 19 to 33 are advantageously so mounted on the upright 11 or supports connected thereto that they perform a circulating movement when the support ring 4 is set in rotation. The relative positions of the various components are apparent from FIGS. 1 and 2.
The parts 19 to 33 form a transmission which couples the bevel gear 18 forming the drive source to the take-down roller 15. It comprises a V-belt transmission formed from the parts 25, 26 and 27, determines the transmission ratio between the bevel gear 19 and the take-down rollers 14, 15 and 16 and thus between these and the needle cylinder 2 and thus determines in known manner the tension under which the goods 17 are held in being taken down from the needle cylinder 2.
In order to effect the stepless adjustment of the take-down tension it is provided in accordance with the invention to make the V-belt pulley 25 in accordance with FIGS. 3 and 4. Accordingly two side plates 35,36 are fixed on the shaft 24, which is mounted rotatably in bearings 34 fitted to the upright 11, on which plates are formed or mounted facing sleeves 37,38 coaxial with the shaft 24. The sleeves 37,38 have a somewhat larger inner diameter than the outer diameter of the shaft 24 and therefore form annular spaces 39 and 40. A guide collar 41,42 is arranged in each of these and each collar 41,42 is mounted to be axially movable but rotationally fast with the shaft 24, by means of groove and key connection or the like. A coaxial, conical flange 43,44 is fixed to each of the guide collars 41,42, being so inclined relative to the shaft 24 that the two flanges 43,44 together form a V-shaped receiving channel for the V-belt 26, likewise V-shaped.
The two flanges 43 and 44 are biased by means of springs 45 in the shape of or formed into a star in the direction towards one another, the springs 45 abutting corresponding shoulders of the side plates and flanges, 35,36 and 43,44 respectively. On account of the axial movability of the guide collars 41,42 however, the flanges 43,44 can be pushed axially apart in the direction of a double arrow x, spreading the springs 45, until the guide collars 41,42 abut the side plates 35,36.
In the position according to FIG. 3 the flanges 43,44 have a comparatively large spacing, with the result that the V-belt 26 assumes a position 26a, in which it has a small spacing from the axis of the shaft 24. This corresponds to a small effective diameter of the V-belt pulley 25. On the other hand FIG. 4 shows that the flanges 43,44 can also have a comparatively small spacing. In this case the V-belt 26 assumes a position 26b, in which it has a comparatively large radial spacing from the shaft 24, which corresponds to a large effective diameter of the V-belt pulley 25. Commencing from FIG. 3, the position of the V-belt pulley 25 automatically becomes that of FIG. 4 under the action of the springs 45, when the tension in the V-belt 26 falls off.
Automatic control over the effective diameter of the V-belt pulley 25 is thus possible inter alia in that the tension of the V-belt 26 is increased or reduced. This is made use of in accordance with the invention by an arrangement of at least one tensioning roller 47 which is at least partially wrapped round by the V-belt 26. In the embodiment shown in FIG. 2 there is a second tensioning roller 48, the tensioning rollers 47,48 having axes parallel to the axes of the V-belt pulleys 25,27 and also advantageously being operative in the same plane as these.
The tensioning rollers 47,48 are rotatably mounted according to FIG. 2 on sliders 49,50. The sliders 49,50 are provided with internally threaded parts and sections of a threaded spindle 51 pass through these. The slider 49 and the associated section of the threaded spindle 51 are provided with right hand threads and the slider 50 and the associated section of the threaded spindle 51 are provided with left hand threads, although the converse arrangement is possible. Accordingly rotation of the threaded spindle in one direction results in the sliders 49 and 50 closing together whereas rotation in the other direction results in the sliders 49,50 moving apart from each other. The axes of the tensioning rollers 47,48 are thus arranged perpendicular to the direction of movement of the sliders 49,50.
In order to avoid the sliders 49,50 turning with the threaded rod 51 when this is turned, they are mounted slidably but non-rotatably in guides, which are formed in a bar 52 fixed to the upright 11. The bar 52 also has supports at its ends for rotatable mounting of the threaded spindle 51, which is provided with a hand-wheel 53 at one end.
As FIG. 2 shows, the V-belt 26 can be further guided between the V-belt pulleys 25,27 via two guide rollers 54,55, so that it describes in all a somewhat trapezoidal or rhomboidal path. The tensioning rollers 47,48 engage e.g. from the outside on the sections located between the guide rollers 53,54 and the V-belt pulley 27. They run essentially in a straight line or are relaxed with the tensioning rollers 47,48 fully retracted (full-line position in FIG. 2) and which are inwardly bowed and correspondingly tensioned (broken line position in FIG. 2) with the tensioning rollers 47,48 fully advanced.
The adjustment of the take-down tension in the goods takes place in the following manner:
If a higher take-down tension is required, the tensioning rollers 47,48 are separated from one another in the direction of a double arrow X, until they assume for example the position shown in FIG. 2 in full lines. This corresponds, as also shown in FIG. 2 in full lines, to a large diameter of the V-belt pulley 25, whose flanges 43,44 are pressed close together by the springs 45 on account of the small tension in the V-belt 26 (FIG. 4). A consequence of this is that the driven V-belt pulley 27 turns faster and the goods 17 are taken down more rapidly. Should the take-down tension be on the contrary reduced, the tensioning rollers 47,48 are moved towards each other in the direction of a double arrow z by suitable rotation of the threaded spindle 51, until they assume their position shown in broken lines in FIG. 2 for example. This corresponds, as is also shown in broken lines in FIG. 2, to a small diameter of the V-belt pulley 25, because in this case the V-belt 26 pushes the flanges 43,44 away from each other against the force of the springs, on account of its higher tension (FIG. 3). In consequence the V-belt pulley 27 is driven more slowly and the goods 17 are taken down more slowly. Moreover, in each case the position of the tensioning rollers 47,48 which is established is automatically held because of the self-locking created by the threads, so that no special locking devices need be provided.
In this connection, a substantial advantage of the invention is to be seen in that each tensioning rollers 47,48 bears on the V-belt 26 between two fixed rollers 27,54,55, so that fine adjustment of the take-down tension is obtained without altering the axial spacing of the V-belt pulleys 25,27.
A pointer 56 fitted to one of the tensioning rollers (e.g. 47) with an associated scale 57 can serve for reproducible creation of a preselected take-down tension.
The invention is not limited to the described embodiment, which can be modified in many ways. For example, it is possible to provide only one tensioning roller for the V-belt 26 and to provide other means for adjustment of the tensioning roller(s). In particular it is possible to mount the tensioning roller(s) on pivotable levers and to provide them with a locking device. It would further be possible to make the driven V-belt pulley 27 the control pulley instead of the driving V-belt pulley 25. Moreover the transmission as a whole could be designed differently than in FIG. 2. In particular it would be conceivable to provide as the transmission only the described V-belt transmission, e.g. if the take-down device is used in machines other than circular knitting machines, e.g. flat knitting machines, warp knitting machines, cotton machines, weaving machines or the like, or to draw-off other goods, especially threads or web form materials or other flexible goods. In this case the drive source could also act directly on the V-belt pulley 25. Finally it would also be possible to arrange only one of the two flanges 43,44 in the V-belt pulley 25 to be movable, the other in contrast being arranged immovably, insofar as the resultant slight sideways displacements of the V-belt 26 on altering the effective diameter of the V-belt pulley 25 are not a problem in the context of the overall arrangement. | A draw-off device for taking down flexible goods with a steplessly adjustable draw-off tension from a machine producing or processing the goods, the draw-off device has at least one draw-off roller, a drive source, and a V-belt transmission connecting the draw-off roller and the drive source for driving the draw-off roller, the transmission comprising a V-belt pulley having two conical flanges, at least one of the flanges being mounted so as to be axially movable so as to alter an effective diameter of the V-belt pulley, the at least one movable flange being biased by spring force in direction of the other of the flanges, a V-shaped belt at least partially wrapping the V-belt pulley, at least one tensioning roller for and at least partially wrapped by the V-belt, a unit for adjusting the tensioning roller in a preselected position in order to adjust the take-down tension to a preselected value by a respective displacement of the at least one movable flange, and a locking unit for holding the tensioning roller in the preselected position. | 3 |
BACKGROUND OF THE INVENTION
The Journal of Antibiotics, Vol. XXXVII No. 5, page 431 (1984), discloses cepacin, a natural product found to be made up of two compounds; i.e., 5-[3-[3-(hepta-1,2-dien-4,6-diynyl)oriran-2-yl]-3-hydroxy-1-propenyl]dihydro-2(3H)-furanone, a compound of the formula ##STR2## referred to as cepacin A, and 5-[[3-[3-(hepta-1,2-dien-4,6-diynyl)-2-oxiranyl]-2-oxiranyl]hydroxymethyl]dihydro-2(3H)-furanone, a compound having the formula ##STR3## referred to as cepacin B.
Journal of the Chemical Society, 2048 (1963) discloses an acetylenic epoxy alcohol having the formula ##STR4##
Chemische Berichte, 95, 1742 (1962) discloses an acetylenic compound having the formula ##STR5##
Journal of the American Chemical Society 1372 (1953), discloses a diacetylenic tetraolefinic compound having the formula
HC.tbd.C--C.tbd.C--CH═C═CH--CH═CH--CH═CH--CH.sub.2 --CO.sub.2 H.
SUMMARY OF THE INVENTION
Compounds having the formula ##STR6## have antimicrobial activity. In formula I, and throughout the specification, the symbols are as defined below.
R 1 is hydrogen or aryl;
R 2 is hydroxymethyl, carboxyaldehyde, propenalyl, 3-hydroxy-1-propenyl, or 3-hydroxy-1,2-epoxypropyl; and
n is 2 and m is 1 or n is 3 and m is 0; with the proviso that if R 1 is hydrogen, n is 2 and m is 1.
The term "aryl", as used throughout the specification, refers to phenyl and phenyl substituted with 1, 2 or 3 halogen, alkyl (of 1 to 4 carbons), alkoxy (of 1 to 4 carbons) or trifluoromethyl groups.
DETAILED DESCRIPTION OF THE INVENTION
The compounds of formula I wherein n is 3 and m is 0 can be prepared by first coupling an aryl diacetylene having the formula
R'.sub.1 --(C.tbd.C).sub.2 --H, II
wherein R' 1 is aryl, with a 1-bromo substituted acetylene having the formula
Br--C.tbd.C--CH═CH--CH.sub.2 --OH. III
The coupling is carried out in the presence of a copper catalyst, e.g., cuprous chloride, and yields the corresponding compound having the formula
R'.sub.1 --(C.tbd.C).sub.3 --CH═CH--CH.sub.2 --OH. IV
Oxidation of a compound of formula IV using a vanadium catalyst and an oxidizing agent such as t-butyl hydroperoxide yields a product of this invention having the formula ##STR7## as a racemic mixture. To get an enantiomerically pure product, tetraisopropoxy titanium and (+)- or (-)-dimethyl tartrate, and t-butyl hydroperoxide can be used when oxidizing a compound of formula IV. The use of (+)-dimethyl tartrate yields one enantiomer of the compound of formula V and the use of (-)-dimethyl tartrate yields the other enantiomer of the compound of formula V.
Oxidation of a compound of formula V using, for example, chromium trioxide, yields the corresponding product of this invention having the formula ##STR8##
Treatment of a compound of formula VI with a Wittig agent yields the corresponding product of this invention having the formula ##STR9##
Reduction of a compound of formula VII with a reducing agent such as diisobutylaluminum hydride yields the corresponding product of this invention having the formula ##STR10##
Oxidation of a compound of formula VIII using a vanadium catalyst and an oxidizing agent such as t-butyl hydroperoxide yields the corresponding product of this invention having the formula ##STR11## Oxidation can also be accomplished using tetraiso-propoxy titanium, (+)- or (-)-dimethyl tartrate, and t-butyl hydroperoxide. The stereochemistry of a compound of formula IX will depend on the stereo-chemistry of the starting compound of formula VIII (racemic or enantiomerically pure) and on the reactants used for the oxidation. The compound of formula IX can be a mixture of diastereomers or a single diastereomer. These diastereomers can be racemic or enantiomerically pure.
The compounds of formula I wherein n is 2 and m is 1 can be prepared by first initiating a palladium-mediated coupling between a zinc acetylide having the formula
R.sub.1 --(C.tbd.C).sub.2 --ZnCl X
and a monosubstituted acetylene having the formula ##STR12## wherein "OL" is a leaving group such as acetate, tosylate, mesylate or the like, to obtain the corresponding compound having the formula ##STR13##
Conversion of a compound of formula XII to the corresponding product of this invention wherein R 2 is hydroxymethyl can be accomplished by treating a compound of formula XII with methanol (or other deprotecting conditions) to obtain the corresponding compound having the formula
R.sub.1 --(C.tbd.C).sub.2 --CH═C═CH--CH═CH--CH.sub.2 --OH. XIII.
Conversion of a compound of formula XIII to the corresponding products of this invention wherein R 2 is carboxyaldehyde, propenalyl, 3-hydroxy-1-propenyl, and 3-hydroxy-1,2epoxypropyl, can be accomplished using the sequential methodology described above for the conversion of a compound of formula IV to the corresponding products of formula I.
The compounds of this invention each contain at least one asymmetric carbon atom and accordingly exist in stereoisomeric forms or racemic mixtures thereof. The preparation of a mixture of diastereomers or a single diastereomer, said diastereomers being racemic or enantiomerically pure has been described above. All are contemplated as part of this invention.
The compounds of this invention have activity against a range of gram-negative and gram-positive organisms and can be used as agents to combat bacterial infections (including urinary tract infections and respiratory infections) in mammalian species, such as domesticated animals (e.g., dogs, cats, cows, horses, and the like) and humans.
For combating bacterial infections in mammals, a compound of this invention can be administered to a mammal in need thereof in an amount of about 1.4 mg/kg/day to about 350 mg/kg/day, preferably about 14 mg/kg/day to about 100 mg/kg/day. All modes of administration which have been used in the past to deliver penicillins and cephalosporins to the site of the infection are also contemplated for use with the compounds of this invention. Such methods of administration include oral, intravenous, intramuscular, and as a suppository.
The following examples are specific embodiments of this invention.
EXAMPLE 1
(trans)-3-(7-Phenyl-1,2-heptadiene-4,6-diynyl)-oxiranemethanol
(A) trans-2-Butene-1,4-diol, monotetrahydropyranyl ether
To a solution of trans-2-butene-1,4-diol (7.57 g, 85.9 mmole) and a catalytic quantity of p-toluenesulfonic acid in 700 ml of dry ether was added dihydropyran (6.73 ml, 71.6 mmole) at the rate of 1.5 ml/hour. After stirring for four days, the reaction mixture was washed with saturated sodium bicarbonate, and the organic layer was separated and dried over sodium sulfate and concentrated in vacuo to afford the crude product which was purified via flash chromatography (LPS-1 silica gel; ether-hexane 1:1) to provide the title compound (5.75 g).
(B) 4-Hydroxy-2-butenal, tetrahydropyranyl ether
trans-2-Butene-1,4-diol, monotetrahydropyranyl ether (5.57 g, 33.4 mmole) and 42 g (0.48 mole) of activated manganese dioxide were stirred in 300 ml of dry methylene chloride under nitrogen for 24 hours. The reaction mixture was filtered through Celite, washed copiously with methylene chloride and concentrated in vacuo. The crude product was purified via flash chromatography (LPS-1 silica gel; ether-hexane 1:1) to afford 1.83 g of the title compound along with 1.75 g of recovered starting material.
(C) 6-[(Tetrahydro-2H-pyran-2-yl)oxy]-4-hexen-1-yn-3-ol
A stirred, saturated solution of acetylene in 22 ml of dry tetrahydrofuran at -78° C. was treated dropwise with n-butyllithium (11.9 mmole). After stirring 10 minutes at -78° C., 4-hydroxy-2-butenal, tetrahydropyranyl ether (1.83 g, 10.8 mmole) in 3 ml of dry tetrahydrofuran was added dropwise. After stirring at -78° C., the reaction mixture was warmed to room temperature. Water (4 ml) was added followed by anhydrous potassium carbonate until the aqueous phase became pasty. The organic phase was decanted and the aqueous layer was washed with ether. The combined organic phase was dried over magnesium sulfate and concentrated in vacuo. Flash chromatography of the crude product (LPS-1 silica gel; ethyl acetate-hexane 1:1) afforded the title compound which was distilled (bulb-to-bulb) to provide pure material (1.55 g).
(D) 10-Phenyl-deca-7,9-diyne-2,4,5-trien-1-ol, tetrahydropyranyl ether
n-Butyllithium (1.5 mmole) was added dropwise to a stirred -78° C. solution of phenyl-diacetylene (189 mg, 1.5 mmole) in 15 ml of dry tetrahydrofuran. The mixture was stirred for one-half hour at -78° C. and then warmed to -20° C. whereupon a solution of anhydrous zinc chloride in tetrahydrofuran (2.1 ml of a 0.78 M solution; 1.5 mmole) was added dropwise. After addition was complete, the mixture was stirred at -20° C. for one-half hour whereupon a catalytic amount of tetrakis (triphenylphosphine) palladium (O) was added (30 mg dissolved in 1 ml of tetrahydrofuran). The mixture was stirred for one-half hour at -20° C.
In a separate flask, the mesylate of 6-[(tetrahydro-2H-pyran-2-yl)oxy]-4-hexen-1-yn-3-ol was prepared via the following procedure. To a stirred solution of 6-[(tetrahydro-2H-pyran-2-yl)oxy]-4-hexen-1-yn-3-ol (294 mg, 1.5 mmole), anhydrous lithium bromide (130 mg, 1.5 mmole), and a few milligrams of 1,10-phenanthroline in 7 ml of tetrahydrofuran at -78° C. was added n-butyllithium dropwise until a brown solution was obtained (ca. 1.5 mmole of n-butyllithium). The mixture was stirred for one-half hour at -78° C. whereupon mesyl chloride (114 μl, 171 mg, 1.5 mmole) was added dropwise. The brown color discharged to yellow. The solution was stirred for one-half hour at -78° C. and was then added all at once (via a short Teflon cannula and argon pressure) to the above stirred -20° C. solution of zinc phenyldiacetylene. The resultant mixture was stirred at -20° C. for 15 minutes and was then acidified by the addition of a solution of acetic acid in tetrahydrofuran. This mixture was then concentrated to ca. 1/4 volume and 30 ml of a mixture of ether-hexane 1:1 was added with stirring whereupon a gum separated. The supernatant was then filtered through a pad of silica gel. The filtrate was then concentrated to dryness and immediately redissolved in a few ml of ether-hexane 1:5 (some solid does not dissolve). This solution of crude product was then purified via flash chromatography (LPS-silica gel, ether-hexane 1:10) to afford the title compound (90 mg). This allene must be stored in a non-basic, non-hydroxylic solvent in the freezer.
(E) 10-Phenyl-7,9-decadiyne-2,4,5-trien-1-ol
To a stirred solution 40 mg of 10-phenyldeca-7,9-diyne-2,4,5-trien-1-ol, tetrahydropyranyl ether in tetrahydrofuran-acetonitrile 1:3 was added one drop of 15% aqueous hydrochloric acid. The mixture was stirred at room temperature for four hours. Most of the solvent was then removed in vacuo and the residue was taken up in ether. The ethereal solution was washed three times with water, once with brine and dried over sodium sulfate. The crude product was flash chromatographed (LPS-1 silica gel, ether-hexane 1:7) to afford 8 mg of the title compound plus 16 mg of recovered starting material.
(F) (trans)-3-(7-Phenyl-1,2-heptadiene-4,6-diynyl)oxiranemethanol
To a stirred solution of 20 mg (0.090 mmole) of 10-phenyl-7,9-decadiyne-2,4,5-trien-1-ol in 4 ml of benzene was added 2 mg of vanadyl acetylacetonate and 50 μl (0.26 mmole) of a 5.43M solution of t-butyl hydroperoxide in benzene. The mixture was stirred for two hours. The mixture was concentrated and the residue was purified via flash chromatography to afford 7 mg of the title compound as an approximately 1:1 mixture of diastereomers.
EXAMPLE 2
(trans)-3-(1,2-Heptadiene-4,6-diynyl)oxiranemethanol (2 isomers)
(A) 2,4,5-Decatriene-7,9-diyn-1-ol, tetrahydropyranyl ether
n-Butyllithium (0.5 mmole) was added slowly dropwise to a stirred -78° C. solution of diacetylene (1.0 mmole) in 15 ml of dry tetrahydrofuran. The mixture was stirred for one-half hour at -78° C. and then warmed to -20° C. whereupon a solution of anhydrous zinc chloride in tetrahydrofuran (0.5 mmole; 0.68 ml of a 0.73 M solution) was added rapidly dropwise. After addition was complete, the mixture was stirred at -20° C. for one-half hour whereupon a catalytic amount of tetrakis(triphenylphosphine)palladium (O) was added (20 mg dissolved in 1 ml tetrahydrofuran). The mixture was stirred for one-half hour at -20° C.
In a separate flask, the mesylate of 6-[(tetrahydro-2H-pyran-2-yl)oxy]-4-hexen-1-yn-3-ol was prepared via the following procedure. To a stirred solution of 6-(tetrahydro-2H-pyran-2-yl)oxy]-4-hexen-1-yn-3-ol (98 mg, 0.5 mmole), anhydrous lithium bromide (43 mg, 0.5 mmole) and a few milligrams of 1,10-phenanthroline in 5 ml of tetrahydrofuran at -78° C. was added n-butyllithium dropwise until a brown color was obtained (ca. 0.5 mmole of n-butyllithium). The mixture was stirred for one-half hour whereupon mesyl chloride (38 μl, 0.5 mmole) was added dropwise. The brown color discharged to yellow. The solution was stirred for 10 minutes at -78° C. and was then added all at once (via short teflon cannula and argon pressure) to the above stirred -20° C. solution of zinc diacetylene. The resultant mixture was stirred at -20° C. for 15 minutes and was then acidified by the addition of a solution of acetic acid in tetrahydrofuran. The mixture was then concentrated to ca. 1/4 volume and 30 ml of a mixture of ether-hexane 1:1 was added with stirring whereupon a gum separated. The supernatant was then filtered through a pad of silica gel. The filtrate was concentrated to dryness and immediately redissolved in a few ml of ether-hexane 1:5 (some solid did not dissolve). This solution of crude product was then purified via flash chromatography (LPS-1 silica gel, ether-hexane 1:10) to afford pure title compound (30 mg). This allene was stored in solution in ether-hexane in the freezer.
(B) 2,4,5-Decatriene-7,9-diyn-1-ol
A solution of 95 mg (0.42 mmole) of 2,4,5-decatriene-7,9-diyn-1-ol, tetrahydropyranyl ether was stirred in 37 ml of reagent methanol for 2 hours at room temperature. The solvent was removed in vacuo and the residue immediately redissolved in ca. 1 ml of ether-hexane 1:3. This solution of crude product was then purified by flash chromatography (LPS-1 silica gel, ether-hexane 1:5) to afford 41 mg of the title compound which was stored in ether-hexane solution in the freezer.
(C) (trans)-3-(1,2-Heptadiene-4,6-diynyl)oxiranemethanol
To a stirred solution of 39 mg (0.27 mmole) of 2,4,5-decatriene-7,9-diyn-1-ol in 7 ml of dry benzene was added 10 mg of vanadyl acetylacetonate and 200 μl (1.09 mmole) of a 5.43M solution of t-butyl hydroperoxide in benzene. The mixture was stirred for 3 hours at room temperature. The mixture was concentrated to a small volume (ca. 1.5 ml) and purified via flash chromatography (LPS-1 silica gel, ether-hexane 1:5) to afford 5.3 mg of one epoxide diastereomer of the title compound (Rf 0.24, ethyl acetate-hexane 1:3) and 8.0 mg of the second epoxide diastereomer of the title compound (Rf 0.20, ethyl acetate-hexane 1:3).
EXAMPLE 3
(trans)-3-(6-Phenyl-1,3,5-hexatriynyl)oxiranemethanol
(A) (E)-9-Phenyl-2-nonene-4,6,8-triyn-1-ol
Freshly prepared phenyldiacetylene (4.0 g, 31.7 mmole) was dissolved in 45 ml of oxygen-free methanol, cooled to 0° C. Cuprous chloride (90 mg) and hydroxylamine hydrochloride (300 mg) were dissolved in 40 ml of oxygen-free 70% aqueous ethylamine, and the resulting solution was then added in one portion to the above stirred solution of phenyldiacetylene. To this mixture was then added dropwise a solution of 6.64 g (41.3 mmole) of 5-bromopent-2-en-4-yn-1-ol in 45 ml of oxygen-free tetrahydrofuran. This mixture was stirred for 45 minutes at 0° C. Water was added and the mixture was extracted with ether. The combined ether extracts were washed with water, brine, and dried over anhydrous magnesium sulfate. Removal of solvent and flash chromatography of the residue on LPS-1 silica gel (ether-hexane, 1:1) afforded 3.15 g of the title compound.
(B) (trans)-3-(6-Phenyl-1,3,5-hexatriynyl)oxiranemethanol
To a stirred solution of 103 mg (0.50 mmole) of (E)-9-phenyl-2-nonen-4,6,8-triyn-1-ol in 20 ml of dry benzene was added 5 mg of vanadyl acetylacetonate and 0.095 ml (0.50 mmole) of a 5.24M solution of t-butylhydroperoxide in benzene. Further 0.095 ml potions of t-butyl hydroperoxide solution were added after 2 hours and 31/2 hours. After stirring for 18 hours, the benzene solution was concentrated and purified via preparative thin layer chromatography (Analtech, 2 mm, silica gel; ether-hexane 1:1) to afford 59 mg of the title compound, melting point 68°-70° C.
Analysis Calc'd. for C 15 H 10 O 2 : C, 81.07; H, 4.54. Found: C, 80.34; H, 4.52.
EXAMPLE 4
(trans)-3-(6-Phenyl-1,3,5-hexatriynyl)oxiranecarboxaldehyde
Chromium trioxide (951 mg, 9.51 mmole; dried in vacuo over phosphorous pentoxide) was added to a stirred solution of 1.49 g (18.88 mmole) of dry pyridine in 25 ml of dry methylene chloride. The deep red solution was stirred for 15 minutes at room temperature. A solution of (trans)-3-(6-phenyl-1,3,5-hexatriynyl)oxiranemethanol (300 mg, 1.35 mmole; see Example 3) in 5 ml of dry methylene chloride was then added in one portion. A tarry, black deposit separated immediately. After stirring for 20 minutes at room temperature, the solution was decanted and filtered through a pad of silica gel. Several portions of ether were then passed through the silica gel. Solvent was removed from the combined filtrates and the residue was chromatographed on silica gel (ether-hexane) to afford 130 mg of the title compound.
EXAMPLE 5
(trans)-3-[3-(6-Phenyl-1,3,5-hexatriynyl)oxiranyl]-2-propenal
(trans)-3-(6-Phenyl-1,3,5-hexatriynyl)oxiranecarboxaldehyde (80 mg, 0.36 mmole; see Example 4) and formylmethylenetriphenylphosphorane (122 mg, 0.40 mmole) were dissolved in 10 ml of dry benzene and the mixture was heated at 70° C. for 10 minutes. The mixture was then cooled to room temperature and the solvent was removed in vacuo. The residue was taken up in ether and filtered through a plug of silica gel. Removal of solvent afforded a brown oil which was purified by chromatography (silica gel, ether-hexane 1:1) to afford 46 mg of the title compound, melting point 91°-92.5° C.
Analysis Calc'd. for C 17 H 10 O 2 : C, 82.91; H, 4.09. Found: C, 82.92; H, 4.19.
EXAMPLE 6
(trans)-3-[3-(6-Phenyl-1,3,5-hexatriynyl)oxiranyl]-2-propen-1-ol
Diisobutylaluminum hydride (0.35 ml of a 1.76 M solution in toluene, 0.61 mmole) was added dropwise to a stirred -78° C. solution of (trans)-3-[3-(6-phenyl-1,3,5-hexatriynyl)oxiranyl]-2-propenal (50 mg, 0.20 mmole; see Example 5) in 6 ml of dry tetrahydrofuran. The mixture was stirred for 2 hours at -78° C. and was then quenched at that temperature by the dropwise addition of ca. 0.5 ml of a solution of methanol-acetic acid 4:1. The mixture was warmed to room temperature, water was added and the mixture was extracted with ether. The combined ether extracts were washed with water and saturated aqueous sodium chloride and were dried over anhydrous magnesium sulfate. Removal of solvent gave an oil which was purified by preparative thin layer chromatography (ethyl acetate-hexane 1:1) to afford 34 mg pure title compound, melting point 65°-66° C.
Analysis Calc'd. for C 17 H 12 .sub. O 2 : C, 82.24; H, 4.87. Found: C, 82.23; H, 4.99.
EXAMPLE 7
(trans)-3-[3-(6-Phenyl-1,3,5-hexatriynyl)oxiranyl]-oxiranemethanol
To a stirred solution of 22 mg (0.089 mmole) of (trans)-3-[3-(6-phenyl-1,3,5-hexatriynyl)oxiranyl]-2-propen-1-ol (see Example 6) in 5 ml of dry benzene was added 2 mg of vanadyl acetylacetonate and 50 μl (0.26 mmole) of a 5.43M solution of t-butylhydroperoxide in benzene. The mixture was stirred for 4 hours. The mixture was concentrated and the residue was purified via preparative thin layer chromatography (silica gel; ethyl acetate-hexane 1:1) to afford 11 mg of the title compound as an approximately 1:1 mixture of diastereomers. | Antimicrobial activity is exhibited by compounds having the formula ##STR1## wherein R 1 is hydrogen or aryl;
R 2 is hydroxymethyl, carboxyaldehyde, propenalyl, 3-hydroxy-1-propenyl, or 3-hydroxy-1,2-epoxypropyl; and
n is 2 and m is 1 or n is 3 and m is 0; with the proviso that if R 1 is hydrogen, n is 2 and m is 1. | 2 |
REFERENCE TO RELATED DOCUMENTS
This application is a divisional of of co-pending patent application Ser. No. 920,014, filed June 28, 1978. Reference is also made to disclosure document Ser. No. 56,889, filed Jan. 11, 1977.
BACKGROUND
Various kinds of water pressure reducing valves are available for use by the plumbing industry. Such valves are used in high rise buildings in order to reduce excessively high pressures found in the water supply system at the lower floors. Installation of such valves, with its specially designed pipings, fittings, added labor, instrumentation and extra required space is rather costly. For the lower floors with pressure reducing valves, a plumbing layout must be provided differing from the layout of the upper floors which have no pressure reducing valves.
Furthermore, installation of pressure reducing valves, when needed, is in addition to the routine installation of the mandated stop valve, commonly called "Stop". This Stop is usually installed at an easily accessible location, near faucets, other plumbing fixtures or equipment to facilitate servicing without shutting off other installations.
High water pressure is provided by pumps at the base of high rise buildings so that water can reach the roof tanks or upper floors. Thus, when lower floors of a high rise building are served by the same water supply system as the upper floors, the lower floors are exposed to excessively high water pressures. Maximum acceptable water pressures at plumbing fixtures are specified in building and plumbing codes in order to prevent accidents, to extend the useful life of installations and to conserve water and energy. Pressure reducing valves are available for all ranges of pressure, both incoming and outgoing, and it is essential that they hold the reduced pressure also at no flow condition.
For convenience in the text, the abbreviation PRV stands for Pressure Reducing or Regulating Valve.
The operational properties of the various available types of PRVs meet the requirements of a wide range of application and installation methods. PRVs with the necessary accessories, are installed either in branch lines near points of water consumption (faucets or outlets) or at distant stations to serve a whole zone. Each zone, consisting of one or several floors, is served by a separate water supply system and such stations are at time equipped with extensive instrumentation, including alarm systems.
For purposes of maintenance of PRVs, another valve the "Shut-Off" valve (sometimes more than one) is installed in the pipe lines. Thus, not only is accessible space required for the PRV but additional approachable space is also needed for the shut-off valve with all its connecting pipings and fittings.
When PRVs are installed in stations, space must be provided there for bypasses, shut-offs, instrumentation and alarm systems. When installed in branch lines, near points of water consumption, space has to be provided in walls, ceilings or cabinets behind access doors.
Installation of any type PRV, therefore, must take into consideration some or all of the following necessities: Special layout for the plumbing system; additional space requirements; additional labor for installations; additional pipings, fittings, instrumentation; provisions for easy access.
Also relevant is that the application of the presently available PRVs requires consideration of the mechanical and hydraulic features. In PRV stations, the number of floors must be limited because of the high hydraulic energy loss in all PRVs. Should there be a failure, a whole zone is thus effected. If installed in branch lines, these problems cannot arise.
As for individual PRVs installed near points of water consumption or in branch lines, such PRVs are usually located behind access doors in walls or in ceilings; most often, they are difficult to reach for adjustment or servicing.
With limited success, improvements have been made for installation near the point of water consumption in water supply lines by combination of PRV and Shut-Off Valves in conventional small sizes. Such combinations, however, have two bonnets and one valve body; one bonnet to reduce water pressure and the other to shut off the water. Because the bonnets are placed on opposite sides of the valve body, or placed side by side in a double body, the dimensions are by necessity quite large and still costly to install. Extended accessible space is still required for installation and servicing, as well as special plumbing layout and special labor.
For fire stand pipes and hose lines, globe and anglebody single bonnet combination pressure reducing valves exist. Due, however, to their special design features, an adaptation, such as a mere reduction in size, would not make them suitable for installation and service in potable water pipelines.
SUMMARY
This invention relates to a combination pressure reducing and stop valve for potable water supply lines in high pressure zones.
The object is to have a combination PRV and Stop valve unit with dimensions, shape and connections enabling it to fit into the space provided in potable water pipelines for the conventional stop valve or Stop.
Another object of the invention is to provide a combination valve with one body and one bonnet thus making it as easily accessible as the bonnet of a Stop valve.
A further object of the invention is that this combination valve should not require a special plumbing layout for high pressure zones, no additional labor, and no additional material whenever installation is required in potable water supply lines with excessively high water pressures.
Still another object is to compose the valve from parts which are designed for durability as well as easy exchangeability in order to provide a life-time comparable to that of a Stop valve.
More specifically, this invention comprises a globe valve or an angle valve with a bonnet and a central threaded valve stem or similar device. This device can be turned in or out by a hand wheel or other means in order to close or open the valve for the flow of water, as is required of a Shut-Off or Stop valve.
Furthermore, the bonnet contains pressure reducing means as described in the following:
Concentrically located is a helical compression spring which exerts an adjustable spring force on the valve disc either in the opening or closing direction. This serves to regulate or reduce the water pressure on the outlet side of the valve--as will be explained in detail in the description of preferred embodiments.
The reduced pressure can be preset by the supplier or adjusted in the field at any time.
The shut off section of such a combination valve is used exactly like a stop valve whenever repairs have to be made, i. e. repairs on faucets, automatic dishwashers and other equipment. If, however, the shut off section is fully open, the valve automatically becomes a PRV. Its spring and other related pressure regulating devices go into action to obtain the specified or desired reduced outlet pressure.
This invention easily allows individual adjustment and equalization of water pressures in the field because the valve itself, and the means of adjustment in it, are readily accessible with conventional tools. This is especially valuable for the hot and cold water supply in bathrooms, washrooms, showers, kitchens, etc.
In the following text, the abbreviation PRV-STOP is used for the combination Stop and Pressure Reducing Valve.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of one version PRV-STOP taken along the centerline extending through the bonnet, valve stem, handwheel, adjusting screw, helical spring, piston, valve disc and seat of a PRV-STOP and thus extending also through the valve body. This version has the body of a globe valve.
Furthermore, FIG. 1 shows a handwheel for opening and closing the stop section, and the pressure reducing section is of the spring actuated single piston type.
FIG. 2 is a sectional view along the centerline of another version. This version differs from the one shown in FIG. 1 because in FIG. 2, the body of an angle valve is shown. However, the elements serving the purpose of shut-off and pressure reduction are identical in FIG. 1 and FIG. 2.
FIG. 3 is a sectional view along the centerline of a third version with a globe body, however, with elements serving the purpose of shut off and pressure reduction differing from the elements shown in FIG. 1 or 2. The stem is protected by a lockshield and has a square end to be turned by a lockshield key. The pressure reducing section is of the balanced double piston type.
FIG. 4 shows a fourth version along the same principles as the third version but with an angle body.
FIG. 5 shows a view and FIG. 6 shows a cross section along the main axis of an angle valve of the type where the bonnet serves the additional purpose of adjusting the spring force for pressure regulation of the spring actuated single piston.
FIG. 7 shows a view and FIG. 8 shows a cross section along the main axis of an angle valve of the type where a hollow stem enclosing the spring can be screwed in or out of the bonnet in order to shut off the valve or to adjust the pressure reduction by adjusting the spring force on the piston. In this version, the pressure reducing section is again of the balanced double piston type.
FIG. 9 is a cross section through that part of an angle valve where the valve seat is located in order to show an exchangeable seat ring.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the present invention, pressure reducing elements have been included in water shut off globe or angle valves. The pressure reducing elements are foremost located in the so-called bonnet of the valve.
The longitudinal movement of the stem activated by its rotation serves the purpose of opening up and closing off the water flow through the valve by acting on the disc of the valve, pressing it against the valve seat or moving it away from the valve seat. Inherent in the stem movement are its stops in the closed position and in the far open position. In the closed position, the flow of water is stopped completely. If the stem however moves into the fully open position, the valve works as a pressure reducing valve at preadjusted pressures by the means described below in the preferred embodiments.
One preferred form of pressure reducing assemblies described here is shown in FIGS. 1 and 2 of the attached drawings. The pressure reducing assembly is contained in the bonnet of the valves. In FIG. 1, the bonnet with the designation 1 is connected with a globe body designated 2. In FIG. 2, an identical bonnet is connected with an anglebody designated 3. In all other respects, the same description is valid in FIG. 1 and FIG. 2.
The wide end designated 8 of the bonnet is connected with the body by a union nut 4. The narrow end of the bonnet carries a female thread 9 to receive the matching thread of the stem 10. The bonnet is closed water tight against the smooth moving end of the stem by any kind of packing. The kind shown consists of packing nut 6, packing 7, and the matching part of the bonnet. The bonnet encloses and guides the stem 10 in its rotating and longitudinal movements along and around its axis 15.
The stem is tubular and has at one end a section with a narrow inside diameter and female thread 11. The other cylindrical section 12 has a wide diameter and is smooth inside and outside. The outside form of the stem shows various diameters providing the necessary wall thickness and in turn the bonnet is constructed to accommodate the stem. The wide end of the stem reaches into the body 2 or 3, and is guided inside the neck 13 of the body for the longitudinal and rotating movement of the stem concentric with axis 15. Inserted into the wide end 12 of the stem is the hollow cylindrical section of the piston 16 allowing the piston to move easily in the longitudinal rotating direction. The drawing shows a version where the cylindrical end of the piston is slotted open to provide wash away space preventing accumulation of clogging matter.
Piston 16 has a seat 21, preferably annular, adapted for contact by piston-engaging surface 20 at the bottom of stem 10. When stem 10 is in the closed position, rotated into bonnet 1 to its fullest extent, it engages piston 16 directly against seat 18, thereby providing full shut-off.
On the other end, the piston carries an exchangeable disc or cone washer 17, made from a suitable semisoft material. This disc closes the valve if the piston presses it tightly against the valve seat, disc seat or seat ring 18 in the valve body partition wall 19.
If the stem is turned the other way, it retracts into the bonnet until the shoulder 22 of the stem hits the end wall of the wide part of the bonnet. In this case, the valve is in the open position and the assembly works as a pressure reducing valve as follows:
The helical compression spring 31 presses against the piston 16 in the closing direction. The spring pressure is adjustable by means of the adjusting screw 23 which can be screwed both ways inside the narrow part of the stem. One end of the adjusting screw carries a spring top 24. The other end has a socket or slot 25, in order to turn the adjusting screw with a socket wrench or screw driver by inserting it into the hollow stem through the front opening 26.
The front opening 26 is closed against the inside water pressure by an end screw 27 and a washer. This screw is also holding handwheel 30 on the stem in this version. This endscrew, however, can be of different design in versions where the stem is turned by other mechanical means instead of the handwheel shown here.
Having described the pressure reducing parts of this version, the pressure reduction assembly will reduce the excessively high water pressure in the inlet 28 of the valve body to an acceptable low water pressure in the outlet 29 of the valve body as follows:
The high pressure on the inlet 28 exerts a lifting force against the piston 16 which in turn is counteracted by the force of the spring 31. As long as the inlet pressure is high enough to lift the piston, water is flowing through the valve seat 18 building up the water pressure on the outlet side 29.
The outlet pressure exerts a counter pressure on the piston in the same direction as the spring, and as soon as the outlet pressure has reached the specified maximum pressure, spring pressure together with the outlet pressure balance the inlet pressure, and the flow of water stops. It is clear for higher inlet pressure, the spring tension must be adjusted higher in order to reduce to the same outlet pressure.
It is also usual to use heavier springs for higher ranges of inlet pressures and vice versa. Nevertheless, it is the preset reduced pressure that, when reached, shuts the flow off through the valve by direct action of the piston.
It can be seen also from the foregoing description that the pressure reducing section is identical with a most frequently used conventional PRV type which is the spring operated direct acting single piston type. This type is simple and practical especially in high rise buildings where the water supply pressure on the inlet side of the valve does not vary at all or very little because gravity feed from tanks or constant pressure supply pump systems are used.
Another preferred version pressure reducing or regulating assemblies is shown in FIG. 3 & 4 of the attached drawings. This kind of assembly satisfies the requirement that the reduced pressure, delivered by the reducing valve, shall not deviate more than 10% of the change in the initial pressure. Although this requirement is not important in most applications, because the initial pressure is steady, the pressure reducing assembly shown in FIGS. 3 and 4 is suitable for all applications. It has the advantage of mechanical and hydraulic simplicity and efficiency. The pressure reducing assembly as well as the shut off assembly are fully contained in the bonnet.
In FIG. 3, the bonnet with the designation 1 is connected with a globe body designated 2. In FIG. 4, an identical bonnet 1 is connected with an angle body designated 3. In all other respects, the same description is valid for FIGS. 3 and 4. Bonnet 1 is screwed pressure tight into neck 4 of the body 2 and 3 by means of the male thread 5 of the bonnet and the female thread in the neck of the body. The narrow end of the bonnet has a female thread 6 to receive the matching thread of the stem 7.
The stem serves two purposes. First, it serves to (close and open the valve) for the flow of water; and second, it serves as the adjusting screw to regulate the reduced pressure. In this version the stem 7 is turned for in and out movement by means of the square head 8. Furthermore, a lock shield 9 is screwed onto the bonnet requiring a conventional lock shield key for turning the stem. All other conventional methods, however, for rotating the stem are also applicable.
On the protruding end, the stem carries a combination of stop nuts 10 and set ring 11 which serve as adjustable stops to limit the movement of the stem in the inward direction. The other end of the stem is shaped as the spring top disc 12 for the helical compression spring 13 inside the bonnet. As the spring top 12 is firmly connected with the stem 7, the stem can only be screwed in the outward direction until the back of the spring top hits the end at the spring chamber section 22 of the bonnet.
The spring 13 exerts a force against the piston assembly 14. The assembly 14 works inside the piston chamber section 21 of the bonnet as a double piston; whereby the inlet water pressure exerts a force on the piston end with the cup washer 15 in the direction against the spring 13. In the opposite direction, the inlet water pressure also exerts a force on the other piston end which carries the valve disc 16, to move it away from the bonnet and seat ring 19.
The inlet water pressure communicates with the piston chamber section of the bonnet through the apertures 17, and permits the flow of water from the valve inlet 18 through the opening of the seat ring 19 to the outlet 20 of the valve.
The inside diameter of the piston chamber 21 or outside diameter of the cup washer end 15 of the piston sliding in the piston chamber is sufficiently larger than the inside diameter of the opening of the seat ring 19 to cause a force bias. This force bias by the inlet pressure forces the piston towards the spring chamber section 22 and thus presses the valve disc 16 against the seat ring 19, shutting off the valve against any water flow. This takes place if stem 7 is, to its full extent, retracted into the top of bonnet 1. Thus the spring 13 no longer exerts a force against the piston assembly 14 which can then move freely. Under this condition, the flow of water stops automatically at any pressure. This means that the valve acts as a stop by screwing the stem out of the bonnet as far as mechanically possible. This is due to the bias force on the cup washer end 15 which is strong enough to press the seat disc 16 tight against the seat ring 19. As previously mentioned, seat ring 19 has a smaller inside diameter than the outside diameter of the cup washer 15.
In order to open the valve for flow, stem 7 has to be screwed into the bonnet. The spring top end of the stem 7 will compress the spring 13 to exert a force against the piston 14 sufficient to move the disc seat 16 away from the seat ring 19, thus opening the valve for flow. This flow will be maintained until a pressure built up on the outlet side develops, exerting a force against the seat end of disc seat 16 of the piston 14, sufficient to overcome the opposing force of spring 13. This closes the disc seat 16 tightly, thus again shutting off the flow through the valve.
As the disc seat is then closed tightly, the pressure on the outlet side of the valve cannot go up further. This outlet pressure is the reduced pressure at which the valve is set. This reduced outlet pressure, or dead end setting, can be adjusted higher or lower by changing the spring pressure by means of screwing the stem 7 more or less into the bonnet, serving simultaneously as an adjusting screw.
The dead end setting can be achieved with the help of the stopnut 10 and set ring 11. In accordance with the above description, the flow through the valve can be stopped by screwing the stem 7 out of the valve as far as it goes--and the valve will function as a pressure reducing valve at the preset outlet pressure if the stem is screwed into the valve as far as it goes.
Still another preferred version of pressure reducing and stop valves, in form of an angle valve of the single piston type, is shown in FIG. 5 and 6 of the attached drawings; differing however from the version shown in FIG. 1 or FIG. 2 by some important features as described below:
Piston 1, with its slim end, slides into the hollow end of stem 2, whereas the spring 4, pressing the piston against the valve seat, is located outside the stem. The valve can be closed or opened completely by screwing stem 2 in or out by means of thread 10 in the bonnet 3. The valve is closed when the inner end 2A of the stem presses piston 1 against the valve seat 12. Piston 1 can move freely when the stem 2 is turned out of the bonnet as far as it can go, thus the valve becomes a pressure reducing valve. The spring force can be adjusted by screwing the bonnet 3 in or out of the body 9. Union nut 5 holds the bonnet 3 in the neck of the valve body 9, and pressure tightness is achieved by O-ring 6 or means to the same effect.
The bonnet 3 can be screwed in or out of the body as far as it goes and the bonnet thus protrudes more, or less, from the body or union nut. The bonnet 3 can thus carry a visible scale 11, indicating the pressure reduction of the valve. The female thread 10, in the bonnet, is long enough to permit the stem 2 to move in or out in any position of the bonnet. This means that the female thread 10, in the bonnet, is as long as that of the male thread of the stem, plus the length of piston movement. The functional features of this stop and pressure reducing valve shown in FIG. 5 and FIG. 6 as an angle valve can just as well be applied to a globe valve.
In FIG. 7 and FIG. 8 of the attached drawings, another preferred version of pressure reducing and stop valve is shown, of the type with balanced double piston. Again, this version is presented as an angle valve, but can just as well be designed as a globe valve. FIG. 7 is a view of the inlet side of this version. FIG. 8 is a cross section along the vertical axis and through the inlet end of the angle valve.
A tubular bonnet 2 is inserted, fitting closely, into the mouth or neck of body 1 and pressed into the body by union nut 3. One or more O-rings in outside grooves of the bonnet 2 assure pressure tightness between body 1 and bonnet 2. The lower end of the bonnet 2 presses valve seat 4 tightly into the partition opening of the valve body. Apertures 14 are located in the lower end of the bonnet 2 in order to allow the valve fluid to flow from the inlet to the valve seat, and out of the valve if the valve disc is in open position. Disc 5 is firmly attached to the double piston 6 by means of washer and nut 13. Piston 6 can slide up and down, pressure tight, in the smooth middle section of bonnet 2. The pressure tightness of the piston between the inside of the valve and the outside atmosphere is assured by such seals as O-rings shown here, or by cup washers as shown previously in FIG. 3 or FIG. 4--or by other sliding seals.
The outside diameter of the sliding piston is larger than the inside diameter of the valve seat 4 at the opposite end of the double piston. This is so in order to produce a bias force in the closing direction of the valve, and to keep the valve closed automatically in consequence of the valve inlet pressure. In order to open the valve, an adjustable spring 8 is provided, pressing against piston 6 to overcome the above bias force, and to push the seat in the outlet direction. Spring 8 will keep piston 6 with valve seat 5 open until pressure on the outlet side of the valve builds up to compensate and stop the flow through the valve once again.
Spring 8 is encased in the hollow valve stem 7 which can be screwed in and out of the top end of the bonnet 2, thus increasing or decreasing the spring force. If stem 7 is screwed all the way out, as far as it goes, until its threaded section touches union nut 3, the spring force is zero. Thus the outlet pressure is reduced to zero and the valve is closed. If the stem 7, is screwed into the bonnet, the spring force against the piston 6 grows, and so does the reduced outlet pressure up to a maximum.
The range of the adjustable reduced outlet pressures depends on the following factors: Inlet pressure, the relation of piston diameter to valve seat diameter, and the size of the spring. Within this range, the outlet pressure can be adjusted to a preferred level by changing the spring compression as described above. It can be preset permanently by means of a set screw 10, screwed into one of the screw holes 11 in stem 7. Such screwholes can be provided in various heights of stem 7.
The set screw 10, inserted into one of the screwholes 11 prevents the stem 7 from being screwed into the bonnet beyond the point where the set screw touches the union nut 3. In accordance with these features, the valve can be closed by screwing the stem out of the valve as far as it goes, and can be opened to the preset reduced pressure by screwing the stem into the valve, as far as it goes. Piston displacement in the direction of opening the valve is limited by a ridge 12 in this form of an angle valve.
FIG. 9 shows a modification of the preferred embodiments, as shown in FIG. 1, FIG., 2, FIG. 5 and FIG. 6. In FIG. 9, part 3 is an exchangeable seat ring made out of a wear resistant material. This seat ring 3 is screwed, or in other ways affixed, into the valve opening 4 of the valve body.
The seat ring 3 serves the purpose of extending the life of the PRV-STOP beyond the life expectancy of the plumbing system wherever this invention is applied.
In the preferred embodiments, FIGS. 3 and 4 or FIGS. 7 and 8, exchangeable seat rings are already shown.
Although the present invention has been described in some detail by way of illustration and example for purposes of clarity and understanding, it is understood that certain changes and modifications may be made within the spirit of the invention and the scope of the appended claims. | For purposes of the stop of flow of water and the reduction of excess pressure in potable or sanitary water supply pipe lines, a Combination Stop and Pressure Reducing valve having one bonnet only. This combination valve, of the same size as the conventional stop valve now used in the plumbing industry, replaces the stop valve at its commonly used location and, simultaneously replaces the pressure reducing valve which is generally installed elsewhere in the pipe lines. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an evaporative fuel-processing system for internal combustion engines, for purging evaporative fuel generated in the fuel tank into the intake system of the engine, and more particularly to an evaporative fuel-processing system of this kind which is capable of performing a diagnosis of abnormality of its own operation.
2. Prior Art
There has been known an evaporative fuel-processing system for an internal combustion engine having a fuel tank, which comprises a canister communicating with a fuel tank, and a purge control valve arranged across a purging passage extending from the canister to the intake system of the engine, wherein evaporative fuel generated in the fuel tank is temporarily stored in the canister and then suitably purged into the intake system of the engine. To determine abnormality of the thus constructed evaporative fuel-processing system, an abnormality-determining method has been proposed, e.g. by Japanese Provisional Patent Publication (Kokai) No. 4-362264, according to which the interior of the evaporative fuel-processing system is negatively pressurized, and then the purge control valve is closed, followed by determining a variation in the pressure within the evaporative fuel-processing system over a predetermined time period after the purge control valve is closed with the system negatively pressurized, to thereby determine whether or not there is an abnormality in the system, based on the determined variation.
However, according to the above proposed conventional method, a pressure sensor which detects pressure within the evaporative fuel-processing system is provided in a charging passage connecting between the fuel tank and the canister, and as a result, there can occur a pressure loss due to flow resistance of a portion of the charging passage extending between the pressure sensor and the fuel tank, so that a value of pressure detected by the pressure sensor (sensor output value) and the actual pressure within the fuel tank do not agree with each other, which may result in that the pressure within the fuel tank cannot be accurately reduced to a desired value.
SUMMARY OF THE INVENTION
It is the object of the invention to provide an evaporative fuel-processing system for internal combustion engines, which is capable of reducing pressure within a fuel tank to a desired value with accuracy, based on a value of pressure detected by a pressure sensor provided in a charging passage connecting between the fuel tank and a canister.
To attain the above object, the present invention provides an evaporative fuel-processing system for an internal combustion engine having an intake system, and a fuel tank, including evaporative emission control means having a canister for adsorbing evaporative fuel generated within the fuel tank, a charging passage extending between the canister and the fuel tank, a purging passage extending between the canister and the intake system of the engine, an open-to-atmosphere passage for communicating an interior of the canister with the atmosphere, a purge control valve arranged in the purging passage, for opening and closing the purging passage, the purge control valve having a valve opening amount thereof being controllable, and an open-to-atmosphere valve arranged in the open-to-atmosphere passage, for selectively opening and closing the open-to-atmosphere passage, and pressure detecting means arranged in the evaporative emission control means, for detecting pressure within the evaporative emission control means.
The evaporative fuel-processing system according to the invention is characterized by comprising:
negative pressure-introducing means for introducing negative pressure from the intake system of the engine into the evaporative emission control means and the fuel tank by opening the purge control valve and closing the open-to-atmosphere valve; and
purge control means operable when the negative pressure-introducing means is operating, for comparing a value of the pressure within the evaporative emission control means detected by the pressure detecting means with a predetermined negative pressure value, and for controlling the valve opening amount of the purge control valve, based on results of the comparison.
Preferably, the purge control means compares the value of the pressure within the evaporative emission control means detected by the pressure detecting means with a first predetermined negative pressure value and a second predetermined negative pressure value which is lower than the first predetermined negative pressure value, the purge control means progressively increasing the valve opening amount of the purge control valve when the value of the pressure within the evaporative emission control means detected by the pressure detecting means reaches the first predetermined negative pressure value, and progressively decreasing the valve opening amount of the purge control valve when the value of the pressure within the evaporative emission control means detected by the pressure detecting means reaches the second predetermined negative pressure value.
More preferably, the purge control means changes the predetermined pressure value according to time elapsed after the negative pressure-introducing means starts to introduce the negative pressure from the intake system of the engine into the evaporative emission control means and the fuel tank.
Specifically, the purge control means changes the second predetermined negative pressure value such that it progressively becomes closer to the first predetermined negative pressure value as time elapses after the start of introduction of the negative pressure into the evaporative emission control means and the fuel tank.
Preferably, the first and second predetermined pressure values are an upper limit value and a lower limit value of a desired negative pressure value to which pressure within the evaporative emission control means is to be reduced by the introduction of the negative pressure into the evaporative emission control means and the fuel tank by the negative pressure-introducing means, respectively.
Also preferably, wherein the negative pressure-introducing means terminates the introduction of the negative pressure into the evaporative emission control means and the fuel tank when the valve opening amount of the purge control valve reaches a predetermined lower limit value after the start of the introduction of the negative pressure into the evaporative emission control means and the fuel tank.
Alternatively, the negative pressure-introducing means terminates the introduction of the negative pressure into the evaporative emission control means and the fuel tank when a predetermined period of time elapses after the valve opening amount of the purge control valve reaches a predetermined lower limit value after the start of the introduction of the negative pressure into the evaporative emission control means and the fuel tank.
Preferably, the negative pressure-introducing means terminates the introduction of the negative pressure into the evaporative emission control means and the fuel tank if the valve opening amount of the purge control valve does not yet reach a predetermined lower limit value when a predetermined period of time elapses after the start of the introduction of the negative pressure into the evaporative emission control means and the fuel tank.
Advantageously, the evaporative fuel-processing system according to the invention further includes open-loop purge control means operable when the negative pressure-introducing means is operating, for controlling the valve opening amount of the purge control valve, irrespective of the value of the pressure within the evaporative emission control means detected by the pressure detecting means.
Preferably, the open-loop purge control means executes the control of the valve opening amount of the purge control valve, before the the first-mentioned purge control means operates to control the valve opening amount.
More preferably, the open-loop purge control means terminates the control of the valve opening amount of the purge control valve when the pressure within the evaporative emission control means reaches a second predetermined negative pressure value.
Also preferably, the negative pressure-introducing means terminates the introduction of the negative pressure into the evaporative emission control means and the fuel tank if the pressure within the evaporative emission control means does not yet reach the second predetermined negative pressure value when a predetermined period of time elapses after the start of the introduction of the negative pressure into the evaporative emission control means and the fuel tank.
The above and other objects, features, and advantages of the invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram schematically showing the whole arrangement of an internal combustion engine and an evaporative fuel-processing system therefor, according to an embodiment of the invention;
FIG. 2 is a flowchart showing a routine for determining preconditions for carrying out fuel tank monitoring;
FIG. 3A is a flowchart showing a main routine for carrying out the fuel tank monitoring;
FIG. 3B is a continued part of the flowchart of FIG. 3A;
FIG. 4A is a flowchart showing a subroutine for carrying out fuel tank negative pressurization, which is executed during execution of the FIG. 3B routine;
FIG. 4B is a continued part of the flowchart of FIG. 4A;
FIG. 5 is a flowchart showing a subroutine for carrying out F/B negative pressurization, which is executed during execution of the FIG. 4A routine;
FIG. 6 is a timing chart showing changes in a desired purging flow rate QEVAP and tank internal pressure PTANK; and
FIG. 7 is a flowchart showing a subroutine for determining abnormality of the fuel tank, which is carried out during execution of the FIG. 3B routine.
DETAILED DESCRIPTION
The invention will now be described in detail with reference to the drawings showing an embodiment thereof.
Referring first to FIG. 1, there is illustrated the whole arrangement of an internal combustion engine and an evaporative fuel-processing system therefor, according to an embodiment of the invention.
In the figure, reference numeral 1 designates an internal combustion engine (hereinafter simply referred to as "the engine") having four cylinders, not shown, for instance. Connected to the cylinder block of the engine 1 is an intake pipe 2, across which is arranged a throttle valve 3. A throttle valve opening (θTH) sensor 4 is connected to the throttle valve 3, for generating an electric signal indicative of the sensed throttle valve opening and supplying the same to an electronic control unit (hereinafter referred to as "the ECU") 5.
Fuel injection valves 6, only one of which is shown, are inserted into the interior of the intake pipe 2 at locations intermediate between the cylinder block of the engine 1 and the throttle valve 3 and slightly upstream of respective intake valves, not shown. The fuel injection valves 6 are connected to a fuel tank 9 via a fuel supply pipe 7 and a fuel pump 8 arranged thereacross. The fuel injection valves 6 are electrically connected to the ECU 5 to have their valve opening periods controlled by signals therefrom.
An intake pipe absolute pressure (PBA) sensor 13 and an intake air temperature (TA) sensor 14 are inserted into the intake pipe 2 at locations downstream of the throttle valve 3. The PBA sensor 13 detects absolute pressure PBA within the intake pipe 2, and the TA sensor 14 detects intake air temperature TA, for supplying electric signals indicative of the sensed values to the ECU 5.
An engine coolant temperature (TW) sensor 15 formed of a thermistor or the like is inserted into a coolant passage formed in the cylinder block, which is filled with a coolant, for supplying an electric signal indicative of the sensed engine coolant temperature TW to the ECU 5.
An engine rotational speed (NE) sensor 16 is arranged in facing relation to a camshaft or a crankshaft of the engine 1, neither of which is shown. The NE sensor 16 generates a signal pulse as a TDC signal pulse at each of predetermined crank angles whenever the crankshaft rotates through 180 degrees, the pulse being supplied to the ECU 5.
Arranged across an exhaust pipe 12 is an O2 sensor 32 as an exhaust gas component concentration sensor for detecting the concentration VO2 of oxygen present in exhaust gases, and generating a signal indicative of the sensed oxygen concentration VO2 to the ECU 5. Further, a three-way catalyst 33 is arranged in the exhaust pipe 12 at a location downstream of the O2 sensor 32, for purifying exhaust gases in the exhaust pipe 12.
Further connected to the ECU 5 are a vehicle speed sensor 17 for detecting the traveling speed VP of an automotive vehicle on which the engine 1 is installed, a battery voltage sensor 18 for detecting output voltage VB from a battery, not shown, of the engine, and an atmospheric pressure sensor 19 for detecting atmospheric pressure PA, of which respective output signals indicative of the sensed values are supplied to the ECU 5.
Next, an evaporative emission control system (hereinafter referred to as "the emission control system") 31 will be described, which is comprised of the fuel tank 9, a charging passage 20, a canister 25, a purging passage 27, etc.
The fuel tank 9 is connected to the canister 25 via the charging passage 20 which has first to third branches 20a to 20c. A tank internal pressure sensor 11 is inserted in the charging passage 20 on one side of the branches 20a to 20c close to the fuel tank 9. The first branch 20a is provided with a one-way valve 21 and a puff loss valve 22 arranged thereacross. The one-way valve 21 is disposed such that it opens only when the tank internal pressure PTANK is higher than the atmospheric pressure by approximately 12 to 13 mmHg. The puff loss valve 22 is an electromagnetic valve, which is opened during purging of evaporative fuel, described hereinafter, and is closed while the engine is in stoppage. The operation of the valve 22 is controlled by a signal supplied from the ECU 5.
The second branch 20b is provided with a two-way valve 23 arranged thereacross, which is disposed such that it opens when the tank internal pressure PTANK is higher than the atmospheric pressure by approximately 20 mmHg and the tank internal pressure PT is lower than pressure on one side of the two-way valve 23 close to the canister 25 by a predetermined value.
The third branch 20c is provided with a bypass valve 24 arranged thereacross, which is a normally-closed electromagnetic valve, and is opened and closed during execution of abnormality determination, described hereinafter, by a signal from the ECU 5.
The canister 25 contains activated carbon for adsorbing evaporative fuel, and has an air inlet port 26b, via a passage (open-to-atmosphere passage) 26a. Arranged across the passage 26a is a drain shut valve 26, which is a normally-open type electromagnetic valve, and is temporarily closed during execution of the abnormality determination, by a signal from the ECU 5.
The canister 25 is connected via the purging passage 27 to the intake pipe 2 at a location downstream of the throttle valve 3. The purging passage 27 is bifurcated into first and second branches 27a and 27b. The first branch 27a is provided with a jet orifice 28 and a jet purge control valve 29 arranged thereacross, and the second branch 27b is provided with a purge control valve 30 arranged thereacross. The jet purge control valve 29 is an electromagnetic valve for controlling an amount of an air-fuel mixture to be purged, within a flow rate range which is so small as cannot be controlled by the purge control valve 30. The purge control valve 30 is an electromagnetic valve which is constructed such that the flow rate of the mixture can be continuously controlled by changing the on/off duty ratio of a control signal therefor. These electromagnetic valves 29 and 30 are controlled by signals from the ECU 5.
The ECU 5 is comprised of an input circuit having the functions of shaping the waveforms of input signals from various sensors, shifting the voltage levels of sensor output signals to a predetermined level, converting analog signals from analog-output sensors to digital signals, and so forth, a central processing unit (hereinafter called "the CPU"), memory means storing programs executed by the CPU and for storing results of calculations therefrom, etc., and an output circuit which outputs driving signals to the fuel injection valves 6, puff loss valve 22, bypass valve 24, jet purge control valve 29, and purge control valve 30.
The CPU 5b operates in response to the abovementioned various engine parameter signals from the various sensors to determine operating conditions in which the engine 1 is operating, such as a feedback control region where the air-fuel ratio is controlled in response to the oxygen concentration in the exhaust gases detected by the O2 sensor 32, and open-loop control regions, and calculates, based upon the determined engine operating conditions, a fuel injection period Tout over which the fuel injection valve 6 is to be opened, in synchronism with generation of TDC signal pulses, by the use of the following equation (1):
Tout=Ti×K1×KO2+K2 (1)
where Ti represents a basic value of the fuel injection period Tout, which is read from a Ti map according to the engine rotational speed NE and the intake pipe absolute pressure PBA.
KO2 represents an air-fuel ratio correction coefficient which is determined based on the concentration of oxygen present in exhaust gases detected by the O2 sensor 32 when the engine 1 is operating in the air-fuel ratio feedback control region, while it is set to predetermined values corresponding to the respective operating regions of the engine when the engine 1 is in the open-loop control regions.
K1 and K2 represent other correction coefficients and correction variables, respectively, which are set according to engine operating parameters to such values as optimize engine operating characteristics, such as fuel consumption and engine accelerability.
An abnormality diagnosis of the evaporative fuel-processing system constructed as above, according to the present embodiment will be carried out by sequentially executing PTANK monitoring, KO2 variation monitoring, canister monitoring, and tank monitoring.
The PTANK monitoring comprises always monitoring pressure PTANK within the fuel tank 9 detected by the tank internal pressure sensor 11, and determine whether or not there is a leak from the fuel tank 9, based on the monitored tank internal pressure PTANK. During the PTANK monitoring, negative pressurization to reduce the pressure within the fuel tank is not carried out.
The KO2 variation monitoring comprises monitoring variations in the air-fuel ratio correction coefficient KO2 during execution of the purging, and determining whether or not evaporative fuel has been supplied in large quantities into the engine intake system through the purging passage 27, based on the monitored variations.
The canister monitoring comprises introducing negative pressure (vacuum developed in the intake pipe 2) into the emission control system 31 to reduce pressure therewithin, and determine whether or not there is a leak from the canister 25, based on a change in the pressure within the emission control system 31 after the reduction of pressure within the emission control system 31.
The tank monitoring will now be described in detail with reference to FIGS. 2 to 6.
FIG. 2 shows a program for determination of satisfaction of preconditions for carrying out the tank monitoring according to the present embodiment.
At a step S161, it is determined whether or not a flag FDONE90, which, when set to "1", indicates that the abnormality diagnosis of the fuel tank side or the canister side has been terminated, is set to "0". In the first loop of execution of the program, the answer to the question is affirmative (YES), and therefore the program proceeds to a step S162, wherein it is determined whether or not a flag FCANIMON, which, when set to "1", indicates that the preconditions for the canister monitoring are satisfied, is set to "0". If the flag FCANIMON is set to "1" and hence the answer to the question is negative (NO), it is determined that the canister is under monitoring in the present loop and hence the tank monitoring cannot be smoothly executed, and therefore the flag FTANKMON, which, when set to "1", indicates that the preconditions for the tank monitoring are satisfied, is set to "0" (unsatisfaction of the preconditions) at a step S163, followed by terminating the present routine.
If the flag FCANIMON is set to "0" and hence the answer to the question at the step S162 is affirmative (YES), it is determined at a step S164 whether or not a flag FTANKOK, which, when set to "1", indicates that the fuel tank side does not suffer from a leak and is in a normal state, is set to "0". In the first loop of execution of the program, the answer to the question is affirmative (YES), and therefore the program proceeds to a step S165, wherein it is determined whether or not any failure diagnosis other than the abnormality diagnosis according to the evaporative fuel-processing system of the present embodiment is being carried out. If the answer to the question is negative (NO), it is determined that execution of the present tank monitoring does not adversely affect the other failure diagnoses, followed by the program proceeding to a step S166. At the step S166, it is determined whether or not the engine 1 is operating in a predetermined operating condition, and if the answer to the question is affirmative (YES), the program proceeds to a step S167.
If any of the answers to the questions at the steps S161, S164 and S166 is negative (NO), or if the answer to the question at the step S165 is affirmative (YES), tank internal pressure (PCONI) before execution of the tank monitoring is set to a present value of the tank internal pressure PTANK and tank internal pressure PATM1 after open-to-atmosphere processing, which is carried out by another subroutine, is set to "0" at a step S168, and further the flag FTANKMON is set to "0" (unsatisfaction of the preconditions) at the step S163, followed by terminating the routine.
At the step S167, a flag FPLVL, which, when set to "1", indicates that negative pressurization of the fuel tank, described hereinafter, has been terminated, is set to "1". In the first loop of execution of the program, the answer to the question is negative (NO), and therefore the program proceeds to a step S169, wherein it is determined whether or not the initial pressure PCONI is lower than a predetermined upper limit value PLIMH and at the same time the tank internal pressure PATM after the open-to-atmosphere processing is lower than a predetermined upper limit value PATMLMH. If the answer to the question is affirmative (YES), it is determined that the amount of generation of evaporative fuel is not large, followed by the program proceeding to a step S170.
At the step S170, it is determined whether or not a cumulative purging flow rate value DQPAIRT is larger than a predetermined value QPTLMT. The cumulative purging flow rate value DQPAIRT is a value obtained by cumulating a purging flow rate calculated based on the valve opening of the purge control valve 30 and a difference (differential pressure) PBG between pressure upstream of the valve 30 and pressure downstream of same, after the start of the engine. If the answer to the question of the step S170 is affirmative (YES), it is determined that the amount of evaporative fuel stored in the canister 25 is not large and at the same time purging is accelerated, which means that execution of the canister monitoring will not unfavorably cause a large variation in the air-fuel ratio, and therefore the program proceeds to a step S171, wherein the flag FTANKMON is set to "1" (satisfaction of the preconditions), followed by terminating the present routine. On the other hand, if the answer to the question at the step S170 is negative (NO), the step S168 is executed, and then the program proceeds to the step S163, wherein the flag FTANKMON is set to "0" (unsatisfaction of the preconditions), followed by terminating the present routine.
In the above KO2 variation monitoring, if a variation in the KO2 value is larger than a predetermined threshold value KO2CHK, it is determined that a large amount of evaporative fuel is being purged, and therefore a flag FKO2OK is set to "1" and the cumulative flow rate value DQPAIRT is reset to "0". Thus, during execution of the KO2 variation monitoring, when the flag FKO2OK is set to "1", the cumulative flow rate value DQPAIRT is set to "0", so that the flow rate again starts to be cumulated from "0" as the cumulative value DQPAIRT. On the other hand, the preconditions for the tank monitoring are not satisfied if the cumulative flow rate value DQPAIRT does not reach the predetermined value QPTLM. Therefore, if the cumulative flow rate value DQPAIRT does not reach the predetermined value QPTLMT within a time period from the time the flag FKO2OK is set to "1" to the time the determination at the step S170 is actually carried out, the preconditions for the tank monitoring can be determined to be unsatisfied. In this manner, according to the present embodiment, when a large amount of evaporative fuel is purged so that the flag FKO2OK is set to "1", the preconditions are made unsatisfied and accordingly the tank monitoring is inhibited, whereby degraded drivability and exhaust emission characteristics due to an excessively rich state of the air-fuel ratio are prevented.
FIGS. 3A and 3B show a main routine for executing the tank monitoring according to the present embodiment.
At a step S181, it is determined whether or not the preconditions for the tank monitoring are satisfied according to the aforedescribed determination of preconditions satisfaction and hence the flag FTANKMON is set to "1". If the answer to the question is negative (NO), a tATMOP timer is set to a predetermined time period T11 required for the open-to-atmosphere processing, carried out hereinafter, to be completed, and then started, at a step S182. Then, at a step S183, a flag FPFB, which, when set to "1", indicates that feedback fuel tank negative pressurization, described hereinafter, is to be executed, is set to "0", and then the program returns to a normal purging mode executed at a step S184 in FIG. 3B, followed by terminating the present routine.
On the other hand, if the answer to the question at the step S181 is affirmative (YES), the program proceeds to a step S185, wherein it is determined whether or not the count value of the tATMOP timer has become equal to "0". In the first loop of execution of the program, the answer to the question is negative (NO), and therefore the program proceeds to a step S186, wherein it is determined whether or not the initial pressure value PCON1 is larger than a threshold value PZERO. If the answer to the question is affirmative (YES), the program proceeds to a step S187, wherein the bypass valve 24, puff loss valve 22, and drain shut valve 26 are opened, the purge control valve 30 is closed, and the jet purge control valve 28 is opened, to thereby relieve the emission control system 31 to the atmosphere. At the following step S188, a tPRG1 timer is set to a predetermined time period T12a required for open-loop fuel tank negative pressurization, carried out subsequently, to be completed, and started, followed by terminating the present routine.
If the answer to the question at the step S186 is negative (NO), it is determined that the fuel tank side has been already brought into a negatively pressurized state, and therefore the open-to-atmosphere processing is skipped over to a step S189, wherein the tATMOP timer is set to "0", and then the step S188 is executed, followed by terminating the present routine.
If the time period T11 has elapsed so that the count value of the tATMOP timer becomes equal to "0" and hence the answer to the question at the step S185 is affirmative (YES), the tank internal pressure PATM after the open-to-atmosphere processing is set to a present value of the tank internal pressure PTANK at a step S190, and then at the following step S191, it is determined whether or not the flag FPLVL is set to "1". In the first loop of execution of the step, the fuel tank negative pressurization has not been completed, so that the answer to the question is negative (NO), and therefore the step proceeds to steps S192 and S193 in order to carry out the fuel tank negative pressurization.
At the step S192, it is determined whether or not the count value of the tPRG1 timer has become equal to "0". In the first loop of execution of the step, the answer to the question is negative (NO), and therefore the program proceeds to the step S193, wherein the fuel tank negative pressurization is carried out according to a subroutine of FIGS. 4A and 4B. If the open-loop negative pressurization has not been completed within the predetermined time period T12a, it means that there is an abnormality in the evaporative emission control system or the fuel tank, such as formation of a large hole in the fuel tank. In such an event, it is impossible to carry out feedback negative pressurization of the evaporative emission control system, hereinafter described, and therefore the open-loop negative pressurization is interrupted, and then the program proceeds to steps S301 et seq.
According to the present embodiment, as stated previously, the tank internal pressure sensor 11 is mounted not within the fuel tank 9 but in the charging passage 20 at a location close to the branches 20a to 20c, which are located in the engine compartment. With this arrangement, there occurs a large difference between the output value from the tank internal pressure sensor 11 and the actual value of the tank internal pressure due to a pressure loss during execution of the negative pressurization. Therefore, the tank internal pressure cannot be accurately detected, which may result in that the fuel tank 9 cannot be negatively pressurized to a desired value with accuracy.
To eliminate the above inconvenience, according to the fuel tank negative pressurization of the present embodiment, the tank internal pressure is estimated from the output value from the tank internal pressure sensor 11 by the program in FIGS. 4A and 4B, to thereby enable negatively pressurizing the fuel tank 9 to the desired pressure value with accuracy.
At a step S221 in FIG. 4A, the bypass valve 24, is opened, and the puff loss valve 22 and the drain shut valve 26 are closed. Then, at a step S224, it is determined whether or not the flag FPFB, which is set to "1" when the PTANK value once falls below a predetermined lower limit value POBJL of a desired negative pressurization pressure value POBJ to which the tank internal pressure PTANK is to be reduced by negative pressurization, is set to "1". In the first loop of execution of the step, the answer to the question is negative (NO), and then the program proceeds to a step S226 to carry out the open-loop fuel tank negative pressurization. That is, at the step S226, it is determined whether or not the PTANK value is lower than an initial value POBJL0 of the predetermined lower limit value POBJL. In the first loop of execution of the step, the answer to the question is negative (NO), the program proceeds to a step S225. At the step S225, a desired flow rate table, which is stored in the memory means of the ECU 5, is retrieved to set a desired purging flow rate QEVAP, based on the present value of the tank internal pressure PTANK. The desired flow rate table is set such that a larger QEVAP value is selected as the PTANK value increases. During execution of the open-loop negative pressurization, the initial value POBJL0 of the lower limit value POBJL of the desired negative pressurization pressure value POBJ is set to a value corresponding to a count value of "0" of a CFB counter which is used in retrieving a POBJL table to be used in the feedback (F/B) fuel tank negative pressurization, hereinafter described.
Then, the program proceeds to a step S227 in FIG. 4B, wherein a purging flow rate QPFRQE to which the purging flow rate is to be controlled by the purge control valve 30 in the present loop is calculated by subtracting a flow rate QPJET through the jet purge control valve 29 from the desired purging flow rate QEVAP determined at the step S225. At the following step S228, it is determined whether or not the purging flow rate QPFRQE calculated at the step S227 is equal to or larger than "0". If the answer to the question is affirmative (YES), it is further determined whether or not the purging flow rate QPFRQE is equal to or smaller than a predetermined upper limit value QPBLIM, at a step S229. If the answer to the question is affirmative (YES), which means that 0≦QPFRQE≦QPBLIM stands, and then the program proceeds to a step S230.
If the answers to the questions at the steps S228 and S229 are negative (NO), at a step S231 the QPFRQE value is set to the lower limit value "0", and then at a step S232 the QPFRQE value is set to the predetermined upper limit value QPBLIM, respectively, followed by the program proceeding to the step S230.
By virtue of the above described processings, the duty ratio of the purge control valve 30 can be calculated based on the negative pressure from the intake system. In addition, the duty ratio is controlled so that the purging flow rate QPFRQE is held at a value within the range defined by the upper and lower limit values. Thus, the variation of the air-fuel ratio during fuel tank negative pressurization can be reduced.
At the step S230, the purge control valve 30 is opened to an opening degree corresponding to the duty ratio, and the jet purge control valve 29 is kept open. Then, at a step S233 it is determined whether or not the air-fuel ratio correction coefficient KO2 is larger than a predetermined threshold value EVPLMT. If the answer to the question is negative (NO), it is determined that a considerably large amount of evaporative fuel is generated, which may cause a large variation in the KO2 value toward a limit value on the lean side, and then at a step S234, the cumulative flow rate value DQPAIRT is reset to "0" in order to inhibit the tank monitoring, followed by terminating the present routine.
On the other hand, if the answer to the question at the step S233 is affirmative (YES), it is determined that the amount of generation of evaporative fuel is small and therefore the tank monitoring can be executed with the air-fuel ratio held stable, and then the program proceeds to a step S235. At the step S235, it is determined whether or not the PTANK value is smaller than a predetermined threshold value PKO2. If the answer to the question is affirmative (YES), it is determined that evaporative fuel has been purged to cause negative pressurization of the fuel tank side, and therefore a flag FKO2OK, which, when set to "1", indicates that an air flow is present, is set to "1" at a step S236, followed by the program proceeding to a step S237. If the answer to the question of the step S235 is negative (NO), the program directly proceeds to the step S237.
At the step S237, it is determined whether or not a tPFBST timer, which is started at the start of the feedback (F/B) negative pressurization, is set to "0". In the first loop of execution of the step, the answer to the question is negative (NO) since the program is presently under the open-loop fuel tank negative pressurization, and therefore the present routine is immediately terminated.
Thereafter, when PTANK<POBJL0 stands during execution of the fuel tank negative pressurization and hence the answer to the question at the step S226 in FIG. 4A becomes affirmative (YES), the program proceeds to a step S241, wherein the flag FPFB is set to "1"; a flag FPOBJ is set to "1", which is set to and held at "1" after the PTANK value falls below the lower limit value POBJL of the desired negative pressurization pressure value POBJ and until it reaches predetermined upper limit value POBJH of same; a flag FQEVAPH is set to "0", which is set and reset in the F/B fuel tank negative pressurization, hereinafter described, and, when set to "1", indicates that the desired purging flow rate is held at an upper limit value thereof; the desired purging flow rate QEVAP is set to an initial value QEVAPST for the F/B fuel tank negative pressurization, described hereinafter; and the CFB counter, which counts the number of times of execution of the F/B fuel tank negative pressurization (step S250), is set to "0"; a tPFBST timer for determining timing of terminating the F/B fuel tank negative pressurization is set to a predetermined time period T13 and started; the aforementioned tPRG1 timer (steps S188 and S192 in FIG. 3A) is set to a predetermined timer period T12b, which is longer than the predetermined time period T12a and started; and the desired negative pressurization pressure value POBJ is set to the predetermined upper limit value POBJH.
After setting at the step S241, the program proceeds to the steps S227 to 237, followed by terminating the open-loop fuel tank negative pressurization. The time point the open-loop negative pressurization is terminated corresponds to a time point t1 in FIG. 6, at which the PTANK value has been negatively pressurized below the lower limit value POBJL0.
In the next loop of execution of the program et seq., the flag FPFB is held at "1", and accordingly the answer to the question at the step S224 becomes affirmative (YES). Therefore, the program proceeds to a step S272, wherein the POBJL table stored in the memory means of the ECU 5 is retrieved to determine a value of the lower limit value POBJL of the desired negative pressurization pressure value POBJ, according to the count value of the CFB counter indicative of the number of times of execution of the F/B negative pressurization (FIG. 5). The POBJL table is set such that the POBJL value is set to a value closer to the upper limit value POBJH of the desired negative pressurization pressure value POBJ as the count value of the CFB counter increases.
Then, at a step S222, it is determined whether or not the flag FPOBJ is set to "1". In the first loop of execution of the step, since it has been set to "1" at the step S241, the answer is affirmative (YES), and the program proceeds to a step S270, wherein it is determined whether or not the present value of the PTANK value is larger than the desired negative pressurization pressure upper limit value POBJH. In the first loop of execution of the step, PTANK<POBJH stands, and therefore the program jumps to the step S250 to carry out the F/B fuel tank negative pressurization according to a program shown in FIG. 5.
At a first step S253 in FIG. 5, it is determined whether or not the flag FPOBJ has been inverted after the F/B fuel tank negative pressurization was started. In the first loop of execution of the program, the answer to the question is negative (NO), and therefore at a step S254 the desired purging flow rate QEVAP is calculated in order to decrease the value QEVAP, by the use of the following equation:
QEVAP=QEVAP+IQ×(PTANK-POBJ) (2)
where IQ represents a control gain for a purging flow rate I (integral) term and is set to a predetermined value. The POBJ value has been set to the upper limit value POBJH (step S241 in FIG. 4A) so that PTANK<POBJ, and therefore the QEVAP value is calculated to a decreased value.
Then, the program proceeds to a step S255, wherein the CFB counter for counting the number of times of execution of the present processing is incremented by a value of "1", and at the following step S256 it is determined whether or not the desired purging flow rate QEVAP is larger than a predetermined lower limit value QEVAPL thereof. If the answer to the question is affirmative (YES), it is determined at a step S257 whether or not the desired purging flow rate QEVAP is smaller than a predetermined upper limit value QEVAPH thereof. If the answer to the question is affirmative (YES), which means that QEVAPL<QEVAP<QEVAPH stands, the tPFBST timer for measuring a time period over which the QEVAP value is held at its limit value is set to the predetermined time period T13 and started, and the flag FQEVAPH, which, when set to "1" indicates that the QEVAP value is held at its upper limit value, is set to "0" at a step S258, followed by terminating the present routine.
On the other hand, if the answer to the question at the step S256 is negative (NO), the desired purging flow rate QEVAP is set to the lower limit value QEVAPL thereof and the flag FQEVAPH is set to "0" at a step S259, while if the answer to the question at the step S257 is negative (NO), the desired purging flow rate QEVAP is set to the upper limit value QEVAPH and the flag FQEVAPH is set to "1" at a step S260, followed by terminating the present F/B negative pressurization. Then, the program returns to the subroutine of FIG. 4B, wherein the steps S227 to S237 are executed, followed by terminating the FIG. 4 subroutine.
Thereafter, the PTANK value increases as the QEVAP value decreases. When PTANK>POBJH stands and accordingly the answer to the question of the step S270 becomes affirmative (YES) (time point t2 in FIG. 6), the program proceeds to a step S271, wherein the flag FPOBJ is reset to "0", and the lower limit value POBJL of the desired negative pressurization pressure value POBJ, determined based on the count value of the CFB counter is set as the desired negative pressurization pressure value POBJ. The lower limit value POBJ at this time point is set to a value closer to the upper limit value POBJH than in the last loop.
Then, the program proceeds to the F/B fuel tank negative pressurization in FIG. 5, wherein the answer to the question of the step S253 is affirmative (YES), and therefore the program proceeds to a step S273, wherein it is determined whether or not FPOBJ="0" stands. In the present loop, the answer to the question is affirmative (YES), and therefore at a step S274, wherein it is determined whether or not the Flag FPOBJ is set to "0". In the present loop, the answer is affirmative (YES), and accordingly at a step S274 the desired purging flow rate QEVAP is calculated in order to increase the value QEVAP, by the use of the following equation (3):
QEVAP=QEVAP+PQ (3)
where PQ represents a purging flow rate P (proportional) term.
Thereafter, the steps S255 et seq. are repeatedly executed, followed by executing the FIG. 4A program and then terminating the program.
In the next loop of execution of the FIG. 4A program, the program proceeds to the step S222, wherein it is determined that FPOBJ="0" stands, and then the program proceeds to a step S223, wherein it is determined whether or not the PTANK value is lower than the lower limit value POBJL. In the first execution of this step, the answer is negative (NO), and then the program jumps to the step S250 to execute the same step, i.e. the F/B negative pressurization. Thereafter, in the F/B fuel tank negative pressurization, the steps S253 and S254 are repeatedly executed, so that the QEVAP value progressively increases and accordingly the PTANK value progressively decreases (t2-t3 in FIG. 6).
At the time point t3 in FIG. 6, PTANK<POBJL stands, and accordingly the answer to the question of the step S223 in FIG. 4A becomes affirmative (YES), so that the flag FOBJ is set to "1" and the desired negative pressurization pressure value POBJ is set to the upper limit value POBJH at the step S240, followed by executing the step S250. On this occasion, the program proceeds through the steps S253 and S273 in FIG. 5 to a step S280, wherein the desired purging flow rate QEVAP is calculated in order to decrease the value QEVAP, by the use of the following equation (4):
QEVAP=QEVAP-PQ (4)
Thereafter, similar processing to that described above is repeatedly carried out, and if in a subsequent loop tPFBST=0 stands so that the answer to the question at the step S237 becomes affirmative (YES) (time point t4 in FIG. 6), it is determined that the flag FPOBJ has never been inverted over the predetermined time period T13 and therefore the time period T13 has elapsed after the QEVAP value became held at the upper limit value, and then the program proceeds to a step S281, wherein the flag FPLVL, which, when set to "1", indicates that the fuel tank negative pressurization has been terminated, is set to "1", followed by terminating the fuel tank negative pressurization.
As described above, according to the fuel tank negative pressurization of the present embodiment, after execution of the open-loop negative pressurization, the F/B negative pressurization is executed. During the latter processing, the purging flow rate is varied according to the output value PTANK from the tank internal pressure sensor 11. On this occasion, by progressively increasing the lower limit value POBJL of the desired negative pressurization pressure value POBJ toward the upper limit value POBJH, the amplitude of the PTANK value is reduced so that it can be finally converged to the desired negative pressurization pressure value. During the F/B negative pressurization thus carried out, the purging flow rate is progressively decreased as a whole, and it becomes equal to and held at the lower limit value QEVAPL when the PTANK value is converged to the desired negative pressurization pressure value. Since the purging flow rate is thus progressively decreased, the pressure loss during negative pressurization is largely diminished or eliminated, so that when the PTANK value is finally converged to the desired negative pressurization pressure value, the difference between the output value PTANK from the tank internal pressure sensor 11 and the actual fuel tank internal pressure is substantially equal to "0". As a result, the PTANK value assumed when it is converged to the desired negative pressurization pressure value is estimated to be equal to the actual tank internal pressure, which makes it possible to negatively pressurize the PTANK value to the desired negative pressurization pressure value with accuracy. P1 in FIG. 6 indicates an estimate value of the tank internal pressure.
Referring again to FIG. 3B, after the fuel tank negative pressurization is terminated, the program proceeds to a step S291, wherein it is determined whether or not the cumulative purging flow rate value DQPAIRT is equal to "0". When the cumulative purging flow rate value DQPAIRT is reset to "0" (at the step S234 in FIG. 4B) during execution of the fuel tank negative pressurization, the answer to the question is affirmative (YES), and then the present routine is terminated. In this case, the answer to the question at the step S170 in FIG. 2 will become negative (NO) in a subsequent loop, and therefore the preconditions for the tank monitoring will be determined to be unsatisfied.
If the answer to the question at the step S291 is negative (NO), a tLEAK timer is set to a predetermined time period (e.g. 16 seconds) T14 required for leak down checking, which is executed following the present fuel tank negative pressurization, to be completed, and started at a step S292, followed by terminating the program.
If the fuel tank negative pressurization has been carried out normally, FPLVL="1" stands, so that the answer to the question at the step S191 in FIG. 3A is affirmative (YES), and then the program proceeds to a step S301 in FIG. 3B. If tPRG1=0 becomes satisfied during the fuel tank negative pressurization and hence the answer to the question at the step S192 becomes affirmative (YES), which means that the open-loop fuel tank negative pressurization or the F/B fuel tank negative pressurization has not been terminated within the predetermined time period T12a or T12b, it is determined that there is a possibility that a leak has occurred from the fuel tank side, and therefore in order to skip a leak down checking in which a variation in the fuel tank pressure is checked, the tLEAK timer is set to "0" at a step S294, followed by the program proceeding to the step S301 in FIG. 3B.
At the step S301, it is determined whether or not tLEAK=0 stands. If the fuel tank negative pressurization has been carried out normally, the answer to the question at the step S301 is negative (NO) in the first loop of execution of the step, and then the program proceeds to a step S302, wherein the fuel tank side is set to a leak-down checking mode. That is, the bypass valve 24, jet purge control valve 29, and purge control valve 30 are closed, while the puff loss valve 22 and drain shut valve 26 are kept closed, and then the tank internal pressure PTANK is measured, and at a step S501 it is determined whether or not the count value of the tLEAK timer is smaller than a value corresponding to a predetermined time period TCLS (e.g. 15.5 seconds). In the first loop of execution of the step, tLEAK≧TCLS stands, and then a value of the PTANK value measured at this time is stored as an initial value PCLS at a step S293, followed by the program proceeding to a step S304.
When tLEAK<TCLS stands in a subsequent loop, the program proceeds to a step S303, wherein a value of the PTANK value then measured is stored as a value PLEAK, and based on the thus obtained PLEAK value, a variation PVARIB in the tank internal pressure PTANK per unit time during leak down checking is calculated, by the use of the following equation:
PVARIB=(PLEAK-PCLS)/T14
Further, a tCANCEL timer for measuring a time period required for completing pressure cancellation, referred to hereinafter, is set to a predetermined time period (e.g. 16 seconds) T15 at a step S304, followed by terminating the present routine.
On the other hand, if the answer to the question at the step S301 is affirmative (YES), the program proceeds to a step S305, wherein it is determined whether or not a flag FNGKUSA is set to "1". The flag FNGKUSA is set and reset in the PTANK monitoring processing, and indicates, when set to "1", that the tank internal pressure PTANK is held at a value equal to or close to the atmospheric pressure. If the answer to the question is negative (NO), it is determined whether or not the count value of the tCANCEL timer has become equal to "0" at a step S306. In the first loop of execution of the step, the answer to the question is negative (NO), and then the program proceeds to a step S307, wherein the pressure cancellation is executed. More specifically, the puff loss valve 22 and purge control valve 30 are held in respective closed states, while the bypass valve 24, drain shut valve 26, and jet purge control valve 29 are opened, to thereby make the pressure within the emission control system 31 substantially equal to the atmospheric pressure. A value of the tank internal pressure PTANK obtained after this pressure cancellation is stored as a value PATM1. Further, a tHOSEI timer, which measures a time period required for completing checking of positive pressure for correction, is set to a predetermined time period T16 and started at a step S308, followed by terminating the present routine.
If the answer to the question at the step S306 is affirmative (YES), it is determined at a step S309 whether or not the count value of the tHOSEI timer has become equal to "0". In the first loop of execution of the step, the answer to the question is negative (NO), and therefore the checking of positive pressure for correction is executed at a step S310. To carry out the checking of positive pressure for correction, the bypass valve 24 is closed, the puff loss valve 22 and purge control valve 30 are held in respective closed states, and the drain shut valve 26 and jet purge control valve 29 are held in respective open states, and a value of the tank internal pressure PTANK detected under the above valve set condition is stored as a value PEND. Further, a variation PVARIC in the tank internal pressure PTANK per unit time during positive pressure checking for correction is calculated based on the above obtained PEND value at a step S311, by the use of the following equation:
PVARIC=(PEND-PATM1)/T16
If the answer to the question at the step S309 becomes affirmative (YES), the program proceeds to a step S312, wherein abnormality determination, described hereinafter, is carried out.
If the answer to the question at the step S305 is affirmative (YES), i.e. if the flag FNGKUSA is set to "1", the program skips over the aforesaid pressure cancellation and the positive pressure checking for correction. More specifically, the program proceeds to a step S313, wherein the variation PVARIC is set to "0", and then at the step S312 abnormality determination is carried out. That is, if the flag FNGKUSA is set to "1", as stated before, the tank internal pressure PTANK is held at a value equal to or close to the atmospheric pressure, which means that the positive pressure checking for correction is not required, thereby omitting the pressure cancellation and the positive pressure checking for correction. Thereafter, the puff loss valve 22 and purge control valve 30 are opened, the bypass valve 24 is kept closed, and the drain shut valve 26 and jet purge control valve 29 are kept open, followed by the program returning to the normal purging mode at the step S184.
FIG. 7 shows a subroutine for executing abnormality determination, which is carried out at the step S312 in FIG. 3B.
At a step S502, it is determined whether or not the flag FQEVAPH (FIG. 5) is set to "1". If FQEVAPH="1" stands, which means that the desired purging flow rate QEVAP is held at the upper limit value, it is determined that there is a leak from the fuel tank side, and then a flag FFSD90 is set to "1", and the flag FTANKOK is set to "0" at a step S325. Further, the flag FDONE90, which, when set to "1", indicates that the fuel tank negative pressurization has been completed, is set to "1" at a step S324, followed by terminating the routine.
If the answer to the question of the step S502 is negative (NO), i.e. FQEVAPH="0" stands, the program proceeds to a step S321, wherein it is determined whether or not the flag FPLVL, which, when set to "1", indicates that the fuel tank negative pressurization has been completed within the predetermined time period T12, is set to "1". If the answer to the question is affirmative (YES), the program proceeds to a step S322, wherein it is determined whether or not the difference between the PVARIB value and the product of KEVAP×PVARIC is smaller than a predetermined value PVARIO. If the answer to the question is affirmative (YES), it is determined at a step S323 that the fuel tank side is in a normal state, and accordingly the flag FTANKOK is set to "1", followed by executing the step S324 and then terminating the present routine. KEVAP represents a coefficient which is determined in response to the desired negative pressurization pressure value, by the use of a KEVAP table, not shown, such that it is set to a larger value as the desired negative pressurization pressure value becomes larger. The rate of generation of evaporative fuel varies with a change in the tank internal pressure, and therefore, the coefficient KEVAP is provided for correcting the determination level according to the desired negative pressurization pressure value so as to compensate for the variation of the generation rate. More specifically, the PVARIB value represents an amount of variation in the tank internal pressure PTANK with respect to a negatively pressurized state (desired negative pressurization pressure value) during execution of the leak down checking, while the PVARIC value represents an amount of variation in the tank internal pressure PTANK with respect to the atmospheric pressure during execution of the positive pressurization for correction. Generation of evaporative fuel is suppressed to a larger degree as the tank internal pressure increases, and therefore the rate of generation of evaporative fuel is different between during leak down checking and during positive pressurization for correction. In the present embodiment, by virtue of the provision of the coefficient KEVAP which is set with the difference in the rate of generation of evaporative fuel taken into account, the determination accuracy can be improved.
If the answer to the question at the step S322 is negative (NO), it is determined that a leak has been occurring from the fuel tank side, and then steps S324 et seq. are executed, followed by terminating the routine.
On the other hand, if the answer to the question at the step S321 is negative (NO), i.e. if the flag FPLVL is set to "0", it is determined whether or not the PVARIC value is larger than the predetermined value PVARIO at a step S326. If the answer to the question is negative (NO), the program proceeds to the step S325, wherein it is determined that the fuel tank side suffers from a leak, and the flags FFSD90 and FTANKOK are set to "1" and "0", respectively, as stated above, followed by executing the step S324 and then terminating the routine. If the answer to the question at the step S326 is affirmative (YES), the program skips over the step 8325 to the step S324 to execute same, followed by terminating the present routine.
Although in the above described embodiment the fuel tank negative pressurization is terminated when the predetermined time period T13 elapses after the QEVAP value reaches the lower limit value QEVAPL, this is not limitative, but it may be terminated immediately when the QEVAP value reaches the lower limit value QEVAPL. | An evaporative fuel-processing system for an internal combustion engine includes an evaporative emission control system comprising charging passage extending between the canister and a fuel tank, a purging passage extending between the canister and an engine intake system, an open-to-atmosphere passage communicating the interior of the canister to the atmosphere, a purge control valve for opening and closing the purging passage, and an open-to-atmosphere valve for selectively opening and closing the open-to-atmosphere passage. A tank internal pressure sensor detects pressure within the evaporative emission control system. An ECU introduces negative pressure from the engine intake system into the evaporative emission control system and the fuel tank by opening the purge control valve and closing the open-to-atmosphere valve. The ECU compares a pressure value detected by the tank internal pressure sensor with a predetermined pressure value, and controls the valve opening amount of the purge control valve, based on the comparison results. | 5 |
FIELD OF THE INVENTION
The present invention relates generally to backplanes and more specifically, transmitter and receiver connection arrangements in a high-speed serial backplane.
BACKGROUND
Serial backplanes have become popular for providing high-speed connections between printed circuit boards (PCBs). Typically, serial backplanes employ a serializer at a transmitting end to convert and transmit data in serial order, and a deserializer at a receiving end to convert the data back to parallel form once received. Such serializer/deserializer (“serdes”) modules have become the benchmark for asynchronous communication and have provided clear advantages over parallel busses.
FIG. 1 is a diagram of two PCBs 110 and 112 connected together via a high-speed serial backplane 114 . Printed circuit board 110 includes a central processing unit (CPU) 120 connected to a random access memory (RAM) 122 and logic 124 . PCB board 110 also includes a serdes 126 connected to logic 124 . The CPU 120 , RAM 122 , logic 124 , and serdes 126 may be part of a programmable logic device (PLD), for example, a field programmable gate array (FPGA) such as Virtex II Pro™ from Xilinx Corp. of San Jose, Calif., which is attached to board 110 . Printed circuit board 112 includes circuitry similar to board 110 (and also may be part of a second FPGA), such as serdes 140 connected to logic 142 , which in turn is connected to CPU 144 and RAM 146 . Serdes 126 is connected to serdes 140 via high-speed serial backplane 114 . Serdes 126 transmits serial data over signal line 132 to the receiver at serdes 140 . Serdes 140 transmits serial data over signal line 136 to the receiver at serdes 126 . Connection points 130 , 133 , 134 , and 137 indicate were a connector may be used to connect the PCBs e.g., boards 110 and 112 , to backplane 114 .
The PCBs (normally called daughtercards), e.g., PCBs 110 and 112 , are affixed to circuit board connectors, which allow the PCBs to be electrically connected to the backplane 114 . Typically a series of circuit board connectors are spaced regularly along the length of the backplane. Multiple circuit layers of the backplane route the transmit and receive signals and power to the connectors and hence connect the PCBs to each other. Plated through holes electrically interconnect runs of different circuit layers as needed.
FIG. 2 is a simplified side view of an example of a daughter card connector 210 and its associated backplane connector 220 of the prior art. This simplified view represents the GbX™ 4-Pair daughtercard signal module, i.e., a daughtercard connector, and backplane signal module, i.e., a backplane connector, of Teradyne Inc. of Boston, MA. A daughtercard 212 may be, for example, board 110 or board 112 of FIG. 1 . The daughtercard 212 is affixed to daughtercard connector 210 . Daughtercard connector 210 is plugged into backplane connector 220 . Backplane connector 220 has the pins, e.g., pins 230 , 231 , 232 , 233 , 234 , 235 , 236 , and 237 . Daughtercard connector 210 has an area 214 , which has the corresponding female structures to receive the pins.
Backplane connector 220 is affixed to backplane 222 (which is similar to backplane 114 of FIG. 1 ). Backplane connector 220 includes an array of pins (e.g., 8×25). FIG. 2 shows a sideview subset of eight pins, e.g., 230 – 237 , and three ground shields 240 , 242 and 244 interposed between each pair of pins, e.g., pin pairs 230 / 231 , 232 / 233 , 234 / 235 , and 236 / 237 , respectively. The pin pairs, e.g., 230 and 231 , may receive/transmit a differential signal, where, for example, pin 230 may be the positive(P) part and pin 231 may be the negative(N) part of the differential signal. For purposes of illustration, the pins 230 – 237 are part of a “column”, e.g., column 310 , in a connector pin assignment array as shown in FIG. 3 . Each ground shield, e.g., 240 , 242 or 244 , is made up of a metal plate and is connected to ground to provide shielding between the pin pairs.
FIG. 3 shows a prior art connector pin assignment 300 for multiple serdes modules on a daughter card. The connector positions TXP 320 and TXN 322 indicate that the positive transmit signal (TXP) of a first serdes and the negative transmit signal (TXN) of the first serdes is assigned to pins 230 and 231 in a first column 310 and first row 350 . The connector positions RXP 324 and RXN 326 indicate that the positive receive signal (RXP) of the first serdes and the negative receive signal (RXN) of the first serdes is assigned to pins in row 350 and column 312 (not shown in FIG. 1 ). Similarly, the connector positions TXP 330 and TXN 332 indicate that the positive transmit signal (TXP) of a second serdes and the negative transmit signal (TXN) of the second serdes is assigned to row 350 and column 314 (not shown in FIG. 1 ). The connector positions RXP 334 and RXN 336 indicate that the positive receive signal (RXP) of the second serdes and the negative receive signal (RXN) of the second serdes is assigned to row 350 and column 316 (not shown in FIG. 1 ). In addition, the connector positions TXP 340 and TXN 342 indicate that the positive transmit signal (TXP) of a third serdes and the negative transmit signal (TXN) of the third serdes is assigned to pins 232 and 233 in column 310 and row 352 . The connector positions RXP 344 and RXN 346 indicate that the positive receive signal (RXP) of the third serdes and the negative receive signal (RXN) of the third serdes is assigned to other pins in a second row 352 and column 312 (not shown in FIG. 1 ). Connector positions TXP 360 and TXN 362 are assigned to pin positions of 234 and 235 in FIG. 1 . Connector positions TXP 364 and TXN 366 are assigned to pin positions of 236 and 237 in FIG. 1 .
The connector pin assignment 300 of FIG. 3 forms an array with columns 310 , 312 , 314 and 316 , and rows 350 , 352 , 354 , and 356 . In each element of the array, for example, column 310 and row 350 , is a differential pair, e.g., TXP 320 and TXN 322 , indicating a positive and negative portion of a differential signal. Ground shields, e.g. 240 , 242 , and 244 , are interposed between each row, e.g., 350 / 352 , 352 / 354 , and 354 / 356 , respectively. The side view in FIG. 2 of backplane 220 shows only the first column 310 and for the example of the GbX™ connector, there may be 25 columns of which only four columns are shown in FIG. 3 .
As the speed of data transmission increases into the gigahertz range and beyond, near-end cross talk becomes a significant problem for connector pin assignments such as that of FIG. 3 . As the transmit signal, is relatively much larger than the receive signal, the transmit signal couples with the receive signal. For example, the differential transmit signal from TXP 320 and TXN 322 couples into the signal received by RXP 324 and RXN 326 and also the signal received by RXP 334 and RXN 336 . Since linear equalization circuits cannot typically distinguish a signal from the crosstalk, it is difficult to correct for the crosstalk using circuitry alone. In addition, the transmit circuits may have a transmit pre-emphasis which aggravates the crosstalk.
One prior technique used to reduce cross talk was to either completely shield the transmitters or the receivers. For example, in FIG. 3 , TXP 320 and TXN 322 would have a ground shields on all four sides. Or, for example, RXP 334 and RXN 336 would have ground shields on all four sides. In effect there would not only be ground shields 240 , 242 , and 244 in the horizontal direction, but ground shields in the vertical direction (not shown) between columns 310 / 312 , 312 / 314 , 314 / 316 , and so forth. In the case of the GbX™ 4-Pair backplane signal module, there may be 25 columns. This is a difficult and expensive solution and is typically impractical to implement.
Therefore, an improved connector pin assignment is needed to reduce the crosstalk in a high-speed serial backplane, where the ground shields are substantially in only one direction.
SUMMARY
The present invention relates generally to a method and system for configuring the transmit and receive elements or structures in connector such that crosstalk can be reduced. The connector connects serdes modules in first PCB to serdes modules in one or more second PCBs via a backplane.
An embodiment of the present invention includes a connector for connecting a circuit board to a backplane. The connector includes: first and second transmit connection positions in a first direction; first and second receive connection positions; and a ground shield positioned in the first direction between the first and second transmit connection positions and the first and second receive connection positions, wherein the first and second transmit connection positions do not have an interposing ground shield in another direction.
Another embodiment of the present invention includes a connector to a serial backplane. The connector includes: first receive connection elements on the connector for at least two serializer/deserializer modules, wherein two of the first receive connection elements do not have a first interposing ground plane; second transmit connection elements for the at least two serializer/deserializer modules, wherein the second transmit connection elements are separated from the first receive connection elements by a second interposing ground plane. The connector may further include: third transmit connection elements for other serializer/deserializer modules, the third transmit connection elements positioned adjacent to the second transmit connection elements, wherein the third transmit connection elements are separated from the second transmit connection elements by a third interposing ground plane; and fourth receive connection elements for the other serializer/deserializer modules, where the fourth receive connection elements are positioned adjacent to the third transmit connection elements, wherein the fourth receive connection elements are separated from the third transmit connection elements by a fourth interposing ground plane.
Yet another embodiment of the present invention has a method for connecting serializer/deserializer modules to a backplane. The method includes a step of selecting transmit/receive pairs from the serializer/deserializer modules, where each transmit/receive pair has an associated transmit connection structure and an associated receive connection structure in a connector; and a step of configuring a ground structure between the associated transmit connection structures and the associated receive connection structures, wherein there is no interposing ground structure between the associated receive connection structures or the associated transmit connection structures.
The present invention will be more full understood in view of the following description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of two PCBs connected together via a high speed serial backplane of the prior art;
FIG. 2 is a simplified side view of an example of a daughter card connector and its associated backplane connector of the prior art;
FIG. 3 shows a prior art connector pin assignment for multiple serdes modules on a daughtercard;
FIG. 4 is a partial connector pin assignment of a preferred embodiment of the present invention;
FIG. 5 is a diagram of some of the connections between two board connectors of an aspect of the present invention;
FIG. 6 is a backplane specification of an aspect of the present invention;
FIG. 7 is a table of the layers of a backplane of an aspect of the present invention.
DETAILED DESCRIPTION
In the following description, numerous specific details are set forth to provide a more thorough description of the specific embodiments of the invention. It should be apparent, however, to one skilled in the art, that the invention may be practiced without all the specific details given below. In other instances, well known features have not been described in detail so as not to obscure the invention.
For serdes modules there is typically a transmit/receive pair of circuits, hence an associated pair of transmit/receive connection elements or structures. In one embodiment of the present invention, the transmit connection elements (or structures) and receive connection elements (or structures) may be pairs of pins indicated by differential pin assignments TXP/TXN and RXP/RXN, respectively. In another embodiment the transmit/receive connection elements or structures may be the corresponding female elements or structures to receive the pairs of pins. In other embodiments rather that differential signals, the signals may be single-ended, e.g., only one pin rather than a pair of pins, and while the following description of the preferred embodiment is for a differential signal, it should be understood that single-ended signals and a mixture of differential and single-ended signals are also included in the scope of the present invention.
From FIG. 3 , one of the reasons there is crosstalk is that there is a mixture of receive connection positions and transmit connection positions in a single row. A preferred embodiment of the present invention has all transmit differential pairs (TXP/TXN) on a first row and the corresponding serdes receive differential pairs (RXP/RXN) on a second row (which may be adjacent to the first row), where the first row and second row are separated by a ground plane or structure, such as a ground shield of FIG. 1 . In the preferred embodiment the ground shields are configured in the backplane connector 220 of FIG. 2 . In an alternative embodiment the ground shields are configured in the daughtercard connector 210 .
FIG. 4 is a partial connector pin assignment 400 of a preferred embodiment of the present invention. The complete connector assignment in the preferred embodiment includes four rows and 25 columns. FIG. 4 shows four columns 410 , 412 , 414 , and 416 and four rows 450 , 452 , 454 , and 456 . The ground planes or structures, for example, ground shields 240 , 242 and 244 (from FIG. 1 ) separate each row. FIG. 4 is similar to FIG. 3 , except the connector pin positions have been reassigned so that each row has only differential receive pin pair connection positions (RXP/RXN) or differential transmit pin pair connection positions (TXP/TXN). The labels for the differential pin pair connection positions in FIG. 4 have been maintained from FIG. 3 to show how the pin pair connection positions have been moved.
For example TXP 320 and TXN 322 which was in row 350 and column 310 of FIG. 3 has been moved to row 452 and column 410 of FIG. 4 . The associated serdes differential receive pair RXP 324 and RXN 326 located in row 350 and column 312 of FIG. 3 has been moved to row 450 and column 410 of FIG. 4 . TPX 340 and TXN 342 in row 352 and column 310 has been moved to row 452 and column 412 . RXP 344 and RXN 346 in row 352 and column 312 has been moved to row 450 and column 412 . TPX 330 and TXN 332 in row 350 and column 314 have been moved to row 452 and column 414 . RXP 334 and RXN 336 in row 350 and column 316 has been moved to row 450 and column 414 . Hence FIG. 4 illustrates a row 450 of receive connection positions adjacent to a row 452 of transmit connection positions, where there is an interposing ground shield 240 between rows. The row 452 is adjacent to row 454 of transmit connection positions, where there is an interposing ground shield 242 between rows. The row 454 is adjacent to a row 456 of receive connection positions, where there is an interposing ground shield 244 between rows. Hence, crosstalk is significantly reduced because the transmit connection positions are shielded from the receiver connection positions.
FIG. 4 shows a row 450 of receive connection positions (abbreviated by “RX1” for discussion purposes). A row 452 of transmit connection positions (abbreviated by “TX1” for discussion purposes). A row 454 of transmit connection positions (abbreviated by “TX2” for discussion purposes). And a row 456 of receive connection positions (abbreviated by “RX2” for discussion purposes). In other words a partial connector pin assignment of [RX1, TX1, TX2, RX2]. Other permutations of partial connector pin assignments are [RX1, TX1, RX2, TX2][TX1, RX1, TX2, RX2] and [TX1, RX1, RX2, TX2].
With reference to FIGS. 2 and 4 , the pins 230 – 237 are reassigned to new values as given in column 410 . RXP 324 and RXN 326 are assigned to pins 230 and 231 . TXP 320 and TXN 322 are assigned to pins 232 and 233 . TXP 360 and TXN 362 are assigned to pins 234 and 235 . RXP 370 and RXN 372 are assigned to pins 236 and 237 .
FIG. 5 is a diagram of some of the connections between two board connectors of an aspect of the present invention. The first board connector includes connector pin assignment 400 and the second board connector includes connector pin assignment 500 . Connector pin assignment 400 was shown in FIG. 4 . Connector pin assignment 500 is similar to connector pin assignment 400 . Connector pin assignment 500 has four rows 550 , 552 , 554 , and 556 , where there are interposing ground shields 502 , 504 , and 506 between each row. Although, only four columns 510 , 512 , 514 , and 516 are shown, there may be 25 columns. Each element in each column of connector pin assignment 400 , e.g., 410 , 412 , 414 , and 416 , is connected to an associated element in the associated column, e.g., 510 , 512 , 514 , and 516 , respectively, in connector pin assignment 500 . For clarity of illustration only one differential connector pin pair position is shown for a row on 400 , e.g., RXP/RXN in column 416 of row 450 is connected to TXP/TXN in column 516 and row 552 . However, the other differential connector pin pair positions in the row on 400 , e.g. row 450 , are similarly connected to the associated differential connector pin pair positions in the row in 500 , e.g., row 552 . TXP/TXN in row 452 and column 414 is connected to RXP/RXN in column 514 and row 550 . TXP/TXN in row 454 and column 412 is connected to RXP/RXN in column 512 and row 556 . RXP/RXN in row 456 and column 410 is connected to TXP/TXN in column 510 and row 554 .
In the preferred embodiment each row in 400 is connected to its associated row in 500 on a different backplane layer. For example, RXP/RXN in row 450 and column 416 is connected to TXP/TXN in row 552 and column 516 via a first layer of the backplane. TXP/TXN in row 452 and column 414 is connected to RXP/RXN in column 514 and row 550 via a second layer of the backplane. TXP/TXN in row 454 and column 412 is connected to RXP/RXN in column 512 and row 556 via a third layer of the backplane. RXP/RXN in row 456 and column 410 is connected to TXP/TXN in column 510 and row 554 via a fourth layer of the backplane. Using different signal layers of the backplane, where there is an interposing ground layer between each signal layer in the backplane, reduces cross talk between signal wires (see U.S. Pat. No. 5,397,861, titled “Electrical Interconnection Board”, by David H. Urquhart, issued Mar. 14, 1995, which is incorporated by reference, herein).
Although the invention has been described in connection with several embodiments, it is understood that this invention is not limited to the embodiments disclosed, but is capable of various modifications, which would be apparent to one of ordinary skill in the art. For example, although only one processor is shown on FPGA 100 , it is understood that more than one processor may be present in other embodiments. Thus, the invention is limited only by the following claims. | A method and system for configuring the transmit and receive elements or structures in connector such that crosstalk can be reduced. The connector connects serdes modules in first PCB to serdes modules in one or more second PCBs via a backplane. The connector includes: first and second transmit connection positions in a first direction; first and second receive connection positions; and a ground shield positioned in the first direction between the first and second transmit connection positions and the first and second receive connection positions, wherein the first and second transmit connection positions do not have an interposing ground shield in another direction. | 7 |
This patent application is a U.S. National Phase of International Patent Application No. PCT/EP2010/057280, filed 26 May 2010, which claims priority to European Patent Office 09161595.5, filed 29 May 2009, the disclosures of which are incorporated herein by reference in their entirety.
TECHNICAL FIELD
The present invention relates in general to pourable food product packaging by transversely sealing a sheet packaging material tube filled continuously with the pourable food product. More specifically, the present invention relates to an electronic counter operable to count the ultrasonic sealing cycles of an ultrasonic sealing device in a Packaging Machine operable to produce sealed packages containing a food product.
BACKGROUND ART
As is known, many pourable food products, such as fruit or vegetable juice, pasteurized or UHT (ultra-high-temperature treated) milk, wine, etc., are sold in packages made of sterilized packaging material.
A typical example of this type of package is the parallelepiped-shaped package for pourable food products known as Tetra Brik Aseptic®, which is made by folding and sealing laminated strip packaging material.
The packaging material has a multilayer sheet structure substantially comprising one or more stiffening and strengthening base layers typically made of a fibrous material, e.g. paper, or mineral-filled polypropylene material, covered on both sides with a number of heat-seal plastic material layers, e.g. polyethylene film. In the case of aseptic packages for long-storage products, such as UHT milk, the packaging material also comprises a gas- and light-barrier material layer, e.g. aluminium foil or ethyl vinyl alcohol (EVOH) film, which is superimposed on a heat-seal plastic material layer, and is in turn covered with another heat-seal plastic material layer forming the inner face of the package eventually contacting the food product.
Packages of this sort are produced on fully automatic Packaging Machines 1 , also known as Filling Machines, of the type shown in FIG. 1 , wherein a continuous vertical tube 2 is formed from the web-fed packaging material 3 , which is sterilized by applying a chemical sterilizing agent such as a hydrogen peroxide solution, which, once sterilization is completed, is removed, e.g. evaporated by heating, from the surfaces of the packaging material. The web-fed packaging material 3 is maintained in a closed, sterile environment, and is folded and sealed longitudinally to form the vertical tube 2 .
The vertical tube 2 is then filled downwards with the sterilized or sterile-processed pourable food product by means of a filling pipe 4 extending inside the tube 2 and equipped with a flow-regulating solenoid valve 5 , and is fed by known devices along a vertical path to a forming station 6 , where it is gripped along equally spaced cross sections by a jaw system including two or more pairs of jaws, which act cyclically and successively on the tube 2 , and seal the packaging material of the tube 2 to form a continuous strip of pillow packs 7 connected to one another by transverse sealing strips. Pillow packs 7 are then separated from one another by cutting the relative sealing strips, and are conveyed to a final folding station (not shown) where they are folded mechanically into the finished, e.g. substantially parallelepiped-shaped, packages 8 .
In the case of aseptic packages with an aluminium layer as the barrier material, the tube 2 is normally sealed longitudinally and transversely by an induction sealing device, which induces parasitic electric current in the aluminium layer to locally melt the heat-seal plastic material. More specifically, for transverse sealing, one of the jaws in each pair comprises a main body made of non-conducting material, and an inductor housed in a front seat in the main body; and the other jaw is fitted with pressure pads made of elastically yielding material, such as rubber.
When the relative pair of jaws grips the tube 2 , the inductor is powered to seal a cross section of the tube 2 by heat sealing the plastic cover material. When powered, the inductor generates a pulsating magnetic field, which in turn produces parasitic electric current in the aluminium sheet in the packaging material from which the vertical tube is made, thus locally melting the heat-seal plastic cover material.
In the case of packages without an aluminium layer or other electrically conductive materials, the tube 2 is normally transversely sealed by a hot plate which locally heats the packaging material from the outside to the inside. More specifically, one of the jaws in each pair is equipped with the hot plate, and the other jaw is fitted with one or more pressure pads made of elastically yielding material. In this type of sealing, known as hot plate sealing, a relatively long time is needed for the hot plate to locally melt the heat-seal plastic cover material, which results in a low package production rate.
In order to improve the performance of the Filling Machines, ultrasonic sealing devices of the type disclosed for example in EP-B-615907 in the name of the present Applicant have been introduced, which essentially comprise an anvil and an ultrasonic transducer, also known as sonotrode, operable to convert electrical energy into ultrasonic mechanical vibratory energy, which are mounted on respective jaws in each pair and cooperate in heating the packaging material by means of ultrasonic vibrations.
DISCLOSURE OF THE INVENTION
Components of ultrasonic sealing devices are typically quite expensive and hence warranty claims may occur if the lifetime thereof is shorter than warranted. Generally, a product warranty is contingent upon proper and regular use of the warranted product, and hence in order to meet both the manufacturers' and the purchasers' need for fair warranty terms and conditions and for fair settlements of warranty disputes, the need is felt by both parties for a solution that allows the operation of the ultrasonic sealing devices to be directly and continuously monitored over time and certified.
However, the operation of ultrasonic sealing devices has proven to be not easily directly monitorable because some components of ultrasonic sealing devices may be used in different Filling Machines at different times. Similarly, indirect monitoring of ultrasonic sealing devices based on production-related data has proven to be unreliable or even unfeasible when this data is not available.
The objective of the present invention is to provide a solution that allows the operation of ultrasonic sealing devices to be continuously, easily, reliably and efficiently monitored over time.
This objective is achieved by the present invention in that it relates to a Packaging Machine and an ultrasonic sealing device, as defined in the appended claims.
The operation of the ultrasonic sealing device is monitored over time by an electronic counter associated with the ultrasonic transducer of the ultrasonic sealing device to count the ultrasonic sealing cycles of the ultrasonic sealing device in the Packaging Machine. The electronic counter may be arranged either in the ultrasonic transducer housing or in a separate housing and electrically connected to the ultrasonic transducer.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention, a preferred embodiment, which is intended purely by way of example and is not to be construed as limiting, will now be described with reference to the attached drawings, wherein:
FIG. 1 shows a perspective view, with omitted parts removed, of a Packaging Machine operable to produce sealed packages containing food products from a tube of packaging material;
FIG. 2 shows an electric diagram of an electronic counter operable to count the number of sealing cycles of an ultrasonic sealing device in a Packaging Machine; and
FIG. 3 shows time charts of electric signals in the electronic counter of FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
The following description is presented to enable a person skilled in the art to make and use the invention. Various modifications to the embodiments will be readily apparent to those skilled in the art, without departing from the scope of the claimed invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein and defined in the appended claims.
FIG. 2 shows an electric diagram of an electronic counter provided in an ultrasonic sealing device in the Filling Machine shown in FIG. 1 to count the sealing cycles or operations performed by the ultrasonic sealing device.
The electronic counter, referenced by 10 , includes:
a couple of input terminals 11 . 1 , 11 . 2 intended to be electrically connected to an ultrasonic sealing device 12 , the sealing operations of which, hereinafter referred to as ultrasonic sealing cycles, are to be counted; a balanced capacitive voltage divider 13 connected to the input terminals 11 . 1 , 11 . 2 ; a voltage bridge rectifier 14 connected to the balanced capacitive voltage divider 13 ; a stabilized electrical power supply 15 , a voltage meter 16 and a counting pulse generator 17 connected to the voltage bridge rectifier 14 ; and a microprocessor-based counter 18 connected to the stabilized electrical power supply 15 , the voltage meter 16 and the counting pulse generator 17 and configured to count both the ultrasonic sealing cycles of the ultrasonic sealing device 12 and the production cycles of the Filling Machine 1 .
More in detail, the ultrasonic sealing device 12 is shown schematically in FIG. 2 limited to only those parts thereof that are necessary to understand the operation of the electronic counter 10 according to the present invention. The ultrasonic sealing device 12 includes an electrical power source 19 operable to supply a pulsed AC power signal V US , and an ultrasonic transducer or sonotrode 20 electrically coupled to the electrical power source 19 to receive and responsively convert the pulsed AC power signal V US into ultrasonic mechanical vibrations to heat seal the sheet packaging material 3 .
The electronic counter 10 may be arranged either in the ultrasonic transducer housing or in a separate housing and electrically connected to the ultrasonic transducer 20 . Serial numbers of both the electronic counter 10 and the ultrasonic transducer 20 are indissolubly associated with each other during assembly and recorded in an appropriate paper or electronic register kept by the ultrasonic transducer manufacturer.
As shown in FIG. 3 , the pulsed AC power signal V US is a train of AC voltage signals spaced apart by one and the same electrical dwell time DT, the value of which depends on the capacity (packages/hour) of the Filling Machine 1 and may be e.g. 0.7 sec. Each AC voltage signal is a sine wave voltage signal with a frequency of few tens of kHz, an RMS (Root Mean Square) amplitude of about a thousand of volts, and a time duration which varies depending on the operation to be performed. In the specific example described, each sine wave voltage signal has a time duration TD which may be either not lower than 70-80 msec, typically 100 ms, during ultrasonic sealing, or of about 50 msec during calibration of the ultrasonic sealing device 12 . In fact, typically every 10 ultrasonic sealing cycles, a calibration cycle is performed to determine the loadless power absorption of the ultrasonic transducer 20 so as to compensate for wear-related drifts thereof.
The balanced capacitive voltage divider 13 is connected to the input terminals 11 . 1 , 11 . 2 to receive the pulsed AC power signal V US and is designed to output a divided pulsed AC power signal V DIV having the same time and frequency characteristics as the pulsed AC power signal V US , but a reduced amplitude of the AC voltage signals. In the specific example shown in FIG. 2 , the balanced capacitive voltage divider 13 includes an even number of capacitors, in the number of six in the example shown in FIG. 2 , which are series-connected between the input terminals 11 . 1 , 11 . 2 , and wherein the intermediate node of series-connected capacitors defines the output of the balanced capacitive voltage divider 13 .
The voltage bridge rectifier 14 is connected to the output of the balanced capacitive voltage divider 13 to receive the divided pulsed AC power signal V DIV and is operable to full-wave rectify the divided pulsed AC power signal V DIV and output a pulsed full-wave rectified power signal V RT . As shown in FIG. 3 , the pulsed full-wave rectified power signal V RT is a train of full-wave rectified voltage signals spaced apart by the aforementioned electrical dwell time DT. Each full-wave rectified voltage signal is a positive or negative half-sine wave voltage signal with a time duration TD equal to that of an AC voltage signal in the pulsed AC power signal V US , a frequency twice that of an AC voltage signal and a positive or negative amplitude half the peak-to-peak amplitude of an AC voltage signal. Moreover, from an operational point of view, each full-wave rectified voltage signal represents an ultrasonic sealing pulse supplied to the ultrasonic transducer 20 of the ultrasonic sealing device 12 , and results in an ultrasonic sealing cycle of the ultrasonic sealing device 12 .
The stabilized electrical power supply 15 is connected to the output of the voltage bridge rectifier to receive the pulsed full-wave rectified power signal V RT and is designed to output a stabilized supply voltage V ST , for example of 3.3 or 5 volts, for the microprocessor-based counting circuit 18 . In particular, the stabilized electrical power supply 15 comprises an input stage 21 and a cascade-connected electrical power supply stage 22 , wherein the input stage 21 includes an capacitor and a parallel-connected Zener diode which are provided to receive the pulsed full-wave rectified power signal V RT and to output an electrical voltage for the cascade-connected electrical power supply stage 20 . More in detail, the capacitor has such a high capacitance, in the example shown in FIG. 2 of about 100 μF, to maintain the electrical voltage across thereto almost stable between successive ultrasonic sealing cycles, which electrical voltage in turn represents the electrical voltage supplied to the cascade-connected electrical power supply stage 20 and would tend to drop between successive ultrasonic sealing cycles due to the power consumption of the microcontroller-based counting stage 18 . The Zener diode is instead provided to limit the maximum electrical voltage supplied to the cascade-connected electrical power supply stage 20 and protect it against higher voltage.
The voltage meter 16 essentially includes an RC filter which is connected to the input stage 21 of the stabilized electrical power supply 15 to receive the same electrical voltage as that supplied to the cascade-connected electrical power supply stage 20 of the stabilized electrical power supply 15 , and is designed to output a voltage level signal V LEV indicative of the amplitude of the electrical voltage across the capacitor of the input stage 21 of the stabilized power supply 15 .
The counting pulse generator 17 essentially includes an RC filter connected to the output of the voltage bridge rectifier 14 to receive the pulsed full-wave rectified power signal V RT and designed to generate counting pulses V P for the microprocessor-based counting circuit 18 . In particular, the RC filter is designed to generate a generally rectangular counting pulse for each full-wave rectified voltage signal in the pulsed full-wave rectified power signal V RT . In view of the characteristics of each of full-wave rectified voltage signal, as shown in FIG. 3 , a counting pulse represents an ultrasonic sealing cycle of the ultrasonic sealing device 12 and hence will have a time duration TD equal to that of a full-wave rectified voltage signal supplied to the ultrasonic transducer 20 , namely equal to or higher than 70-80 msec during ultrasonic sealing, or of about 50 msec during calibration of the ultrasonic sealing device 12 .
The microprocessor-based counter 18 includes a microcontroller 23 connected to the stabilized electrical power supply 15 to receive the stabilized supply voltage V ST , to the voltage meter 16 to receive the voltage level signal V LEV , and to the counting pulse generator 17 to receive the counting pulses V P ; a time clock 24 in the form of a piezoelectric crystal (quartz) oscillator connected to the microcontroller 23 to provide the latter with a stable clock signal; a programming connector or port 25 connected to the microcontroller 23 to allow the latter to be programmed by an appropriately programmed external electronic programming device when the ultrasonic sealing device 12 is inoperative; and a reading/writing connector or port 26 , such as an RS-232 serial port, connected to the microcontroller 23 to allow the latter to be read/written by an appropriately programmed external electronic reading/writing device when the ultrasonic sealing device 12 is inoperative.
The microcontroller 23 is supplied with electrical power from either the electrical power source 19 of the ultrasonic sealing device 12 , when the ultrasonic sealing device 12 is operative, or an external electronic device connected to either the programming port 25 or the reading/writing port 26 , when the ultrasonic sealing device 12 is inoperative. In particular, when the ultrasonic sealing device 12 is operative, the pulsed AC voltage signal V US supplied by the electrical power source 12 thereof is first converted by the stabilized power supply 16 into a stabilized supply voltage V ST , which is then supplied to an appropriate supply pad of the microcontroller 23 .
Moreover, depending on the source of electrical power, the microprocessor 23 is appropriately programmed to operate in three mutually exclusive operating modes:
in a Counting Mode, when the ultrasonic sealing device 12 is operative and the microcontroller 23 is supplied with electrical power from the electrical power source 19 of the ultrasonic sealing device 12 ; in a Terminal Mode, when the sealing device 12 is inoperative and the microcontroller 23 is supplied with electrical power from the external electronic reading/writing device connected to the reading/writing port 26 ; and in a Programming Mode, when the sealing device 12 is inoperative and the microcontroller 23 is supplied with electrical power from the external electronic programming device connected to the programming port 25 .
In the Counting Mode, the microcontroller 23 implements a volatile counter, in the form of a temporary internal register of the microcontroller 23 , to count the ultrasonic sealing cycles of the ultrasonic sealing device 12 , and, optionally, an additional volatile counter, in the form of a temporary internal register of the microcontroller 23 , to count the continuous production cycles of the Filling Machine 1 on which the ultrasonic sealing device 12 is installed.
In particular, as far as the ultrasonic sealing cycle counter is concerned, the microcontroller 23 is programmed to discriminate between ultrasonic sealing cycles and calibration cycles of the ultrasonic sealing device 12 , so as to increase the ultrasonic sealing cycle counter when an ultrasonic sealing cycle occurs. To do so, the microcontroller 23 is programmed to:
distinguish the counting pulses V P having a time duration TD equal to or higher than 70-80 msec from those having a time duration TD lower than about 50 msec by appropriately determining the time duration TD of each counting pulse supplied thereto. To do so, the time duration TD of each counting pulse V P is determined and then compared with a time threshold having an intermediate value between the aforementioned time durations TD; and increase by one the value in the ultrasonic sealing cycle counter when an ultrasonic sealing cycle is distinguished.
As far as the production cycle counter is concerned, the microcontroller 23 is programmed to determine when a production cycle of the Filling Machine 1 occurs, defined as the time span between the Filling Machine 1 being switched on and off, so as to increase the production cycle counter when a production cycle ends. To do so, the microcontroller 23 is programmed to:
sense the voltage level signal V LEV supplied by the voltage meter 16 to detect the amplitude of the electrical voltage across the capacitor of the input stage 21 of the stabilized power supply 15 falling below a switching-off supply voltage of the microcontroller 23 , this event being indicative of the ultrasonic sealing device 12 being switched off and the production cycle of the Filling Machine 1 being terminated; and increase by one the value in the production cycle counter when the voltage level signal V LEV is indicative of the production cycle of the Filling Machine 1 being terminated.
In the end, in order to prevent the values in both the ultrasonic sealing cycle counter and the production cycle counter from being lost when the microcontroller switches off, the microcontroller 23 is further programmed to:
permanently, unresettably and unerasably store in an internal non-volatile memory, such as an EEPROM, of the microcontroller 23 the values in both the ultrasonic sealing cycle counter and the production cycle counter when the voltage level signal V LEV is indicative of the amplitude of the electrical voltage across the capacitor of the input stage 21 of the stabilized power supply 15 falling below the switching-off supply voltage of the microcontroller 23 .
When the ultrasonic sealing device 12 is again operated, the ultrasonic sealing cycle counter and the production cycle counter are again implemented and initialized to the values stored in the internal non-volatile memory of the microcontroller 23 .
In the Terminal Mode, data such as the serial number of the electronic counter 10 , the amount of the ultrasonic sealing cycles of the ultrasonic sealing device 12 and the amount of the production cycles of the Filling Machine 1 , may be read from the internal non-volatile memory of the microcontroller 23 via appropriate reading commands sent by an external electronic reading/writing device. Data, such as the serial number of the electronic counter 10 and, optionally, the serial number of the associated ultrasonic transducer 20 , may also be written in the internal non-volatile memory of the microcontroller 23 via appropriate writing commands sent by the external electronic reading/writing device. Other reading/writing commands may also be sent to the microcontroller 23 by the external electronic reading/writing device to read/write other internal registers of the microcontroller 23 for testing/debugging purposes.
In the end, in the Programming Mode the microcontroller 23 is appropriately programmed to operate as previously described.
The advantages that the electronic counter 10 according to the present allows to achieve may be readily appreciated by the skilled person. In particular, the electronic counter 10 allows the operation of an ultrasonic sealing device 12 to be directly and continuously monitored over time, and in particular the amount of ultrasonic sealing cycles performed by the ultrasonic sealing device 12 to be easily, reliably and efficiently determined, so allowing warranty-related issues to be fairly tackled. | Packaging Machine operable to produce sealed packages made of heat-seal sheet packaging material and containing a food product, and comprising an ultrasonic sealing device including an electrical power signal source operable to generate an electrical power signal; an ultrasonic transducer electrically coupled to the electrical power signal source to receive the electrical power signal and responsively heat seal the sheet packaging material; and an electronic counter operable to count the ultrasonic sealing cycles of the ultrasonic sealing device. | 1 |
This application claims benefit under 35 U.S.C. §119(e) of Provisional Appln. 61/017,128, titled “Method for Automatic Timing Synchronization for Wireless Radio Networks”, filed Dec. 27, 2007, Provisional Appln. 61/017,129, titled “Adaptive Multi Service Data Framing”, filed Dec. 27, 2007, Provisional Appln. 61/017,130, titled “Decision Directed DC Removal Scheme”, filed Dec. 27, 2007, and Provisional Appln. 61/017,132, titled “Means and Apparatus for Mitigation of Thermal Power Slump in Radio Devices by Using a Surrogate Carrier”, filed Dec. 27, 2007, the entire contents of which are hereby incorporated by reference as if fully set forth herein.
FIELD OF THE INVENTION
The present invention relates to radio communications. More specifically, the present invention relates to techniques for removing DC and low frequency noise from radio signals.
BACKGROUND
In radio communications, demodulators in radio receivers convert signals received at radio frequencies into baseband signals and decode the baseband signals to recover the original data. FIG. 1 illustrates a demodulator 100 that demodulates and decodes received radio signal 102 .
In FIG. 1 , demodulator 100 receives radio signal 102 , which is a modulated signal that conveys original data at a radio frequency, or carrier frequency. Radio signal 102 may be analog or digital. If radio signal 102 is analog, it is converted to digital by an analog-to-digital converter (ADC), which is not specifically shown. Radio signal 102 may be a complex-valued signal. In demodulator 100 , radio signal 102 is a complex-valued signal and is applied to two parallel multipliers 124 and 126 . In multiplier 124 , radio signal 102 is multiplied with a function cos(ωt), where ω is 2π times the carrier frequency. In multiplier 126 , radio signal 102 is multiplied with a function sin(ωt), where ω is 2π times the carrier frequency. Outputs 104 and 106 are applied to low-pass filters 116 and 118 , respectively, which provide anti-aliasing and remove out-of-band noise. The outputs 108 and 110 of low-pass filters 116 and 118 are the real and imaginary components, respectively, of a complex baseband signal derived from the received radio signal 102 .
The outputs 108 and 110 are then each applied to decoders 120 and 122 , respectively, to produce decoded signals 112 and 114 , respectively. Decoders 120 and 122 receive outputs 108 and 110 and output decoded signals 112 and 114 , respectively, based on the signal levels in outputs 108 and 110 . Since decoders 120 and 122 perform the same functions, the discussion from this point forward will focus on a single decoder (e.g., decoder 120 ). Techniques discussed with respect to decoder 120 are, however, equally applicable to decoder 122 .
Decoder 120 samples output 108 and generates, based on the signal level of output 108 , a decoded signal 112 whose signal level comprises particular values. In an example, output 108 is a bi-level signal whose signal level is expected to be either +0.5 or −0.5 in any particular sample period. The signal level of output 108 may be expected to be either +0.5 or −0.5 in any particular sample period because it may be known that radio signal 102 is a radio signal that is based on an original baseband signal that was encoded to be either +0.5 or −0.5 in any particular sample period. In this example, decoder 120 compares the signal level of output 108 during a particular sample period to a decision value, which is 0 in this case because 0 is halfway between the encoded values of +0.5 or −0.5. If the signal level of output 108 is greater than 0 during a particular sample period, then decoder 120 will output a decoded signal 112 whose signal level is a first value. If the signal level of output 108 is less than 0 during a particular sample period, then decoder 120 will output a decoded signal 112 whose signal is a second value. The first value and second value may be +0.5 and −0.5, or any other two distinct values.
However, output 108 may also include DC offset noise, which is a low-frequency, slow-changing noise that results in output 108 exhibiting a DC offset. Waveform 202 in FIG. 2 represents a signal that is unaffected by any low-frequency, slow-changing noise and has a signal level of +0.5 or −0.5 in any particular sample period. Waveform 204 represents a low-frequency and slow-changing noise. When the noise represented by waveform 204 is added to the signal represented by waveform 202 , the resultant signal, represented by waveform 206 , exhibits a downward slope such that a signal level that is positive in the original signal represented by waveform 202 , in a particular sample period, may be negative in that same sample period. Consequently, when the signal represented by waveform 206 is input into a decoder such as decoder 120 , a decoding error will result in the particular sample period.
Various methods have been developed to remove this DC offset noise from signals so as to reduce or eliminate decoding errors. These methods include employing a low-frequency high-pass filter to remove the low-frequency components from the signals. However, these methods suffer from slow tracking bandwidth. Alternatively, a wide-band high-frequency filter may be used, but this can cause inter symbol interference. Therefore, there is a need for a method for removing DC offset noise from a signal that allows for fast tracking without decreasing the signal-to-noise ratio of the signal.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
FIG. 1 is a block diagram that illustrates a system for demodulating and decoding a radio signal.
FIG. 2 illustrates waveforms of example signals, DC noise, and signals affected by DC noise.
FIG. 3 is a block diagram that illustrates a system for decoding a baseband signal.
DETAILED DESCRIPTION
In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, that the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the present invention.
Overview
A system and techniques are described for decoding a baseband signal, of a radio signal, that is expected to include certain signal levels. One such system includes a comparator that compares a corrected baseband signal to certain decision values. The comparator outputs, based on the comparison, a decoded signal that is equal to one of the expected signal levels. The difference between the corrected baseband signal and the output of the comparator is accumulated and then subtracted from the baseband signal to produce the corrected baseband signal. The subtraction of the accumulated difference from the baseband signal completes a negative-feedback loop that removes any long-term, low-frequency DC offset exhibited by the baseband signal. The loop produces the corrected baseband signal, which is used as a basis for comparison in determining the output decoded signal, thereby reducing decoding errors caused by the addition of long-term, low-frequency DC noise to radio signals.
According to one technique, the baseband signal is a multi-level signal that is expected to include more than two distinct signal levels.
According to one technique, the baseband signal is a bursty signal that contains a training sequence that precedes a burst of data.
Decision Directed DC Removal
A decoding system 300 in which the present invention may be practiced is illustrated in FIG. 3 . A received signal s(t) 302 is an input to decoding system 300 . Received signal 302 may be a baseband signal, such as signal 108 or signal 110 in FIG. 1 . A subtractor 320 subtracts accumulated value 310 from received signal 300 , producing corrected signal 304 . In decoding system 300 , corrected signal 304 is sampled and held by sample-and-hold module 318 . In other embodiments, it may not be necessary for corrected signal 304 to pass through a sample-and-hold module 318 . In other words, corrected signal 304 may be directly inputted to comparator 312 . In decoding system 300 , sampled corrected signal 306 is inputted to comparator 312 , which determines an output value 322 based on sampled corrected signal 306 .
Comparator 312 compares the signal value of sampled corrected signal 306 in a particular sample period to at least one decision value and, based on the result of the comparison, selects one of at least two distinct values as output value 322 for the duration substantially equal to the length of the particular sample period. The at least two distinct values are equal to the expected signal values of received signal s(t) 302 if received signal 302 is unaffected by noise. The signal level of received signal s(t) 302 may be expected to be certain expected signal values because it may be known that received signal s(t) 302 is based on a radio signal that is in turn based on an original baseband signal that was encoded to be certain expected signal values.
For example, the received signal s(t) 302 may be a signal whose signal value for any particular sample period is expected to be either +0.5 or −0.5 because it is known that received signal s(t) 302 is based on a radio signal that is in turn based on an original baseband signal that was encoded to be either +0.5 or −0.5 in any particular sample period. In this example, comparator 312 uses the decision value of 0 such that if comparator 312 determines that the sampled corrected signal 306 is greater than 0 in the particular sample period, then comparator 312 outputs the value +0.5 as output value 322 . Similarly, if comparator 312 determines that the sampled corrected signal 306 is less than 0 in the particular sample period, then the comparator 312 outputs the value −0.5 as output value 322 . In this example, even if the signal level of sampled corrected signal 306 is only +0.3 for a particular sample period, comparator 312 will output a value of +0.5 in response to comparing the signal level of sampled corrected signal 306 to the decision value of 0.
In other words, although received signal s(t) 302 may have been affected by noise such that the signal level of received signal 302 deviates from the expected signal levels, comparator 312 outputs a value (output value 322 ) that is equal to an expected signal level.
Subtractor 214 subtracts output value 322 from sampled corrected signal 306 and outputs error value 308 . Error value 308 is the difference between the sampled corrected signal 306 and output value 322 , which, as just discussed, is equal to an expected signal level. For example, if sampled corrected signal 306 is +0.7 and output value 322 is +0.5, then error value 308 will be +0.2. In this example, error value 308 may indicate that the overall signal level of sampled corrected signal 306 is exhibiting a positive DC offset of +0.2, which in turn may indicate that received signal s(t) 302 is exhibiting a positive DC offset of +0.2.
Error value 308 is accumulated, or summed, in accumulator 316 . The sum accumulated in accumulator 316 indicates the long-term DC offset exhibited by received signal 302 . In one embodiment, the accumulation of error value 308 in accumulator 306 is performed by an integrator. The accumulated error value, output as signal 310 , is subtracted from received signal 302 s(t) in subtractor 320 to produce corrected signal 304 . The subtraction of the accumulated error value 310 from received signal 302 removes the long-term DC offset indicated by the accumulated error 310 from received signal 302 , thereby producing a corrected signal 304 that contains signal levels that are closer to the expected signal levels.
Corrected signal 304 is sampled and held to produce sampled corrected signal 306 , which is then used by comparator 312 to produce output 322 , thereby completing a negative-feedback loop. As the negative-feedback loop in decoding system 300 stabilizes, error value 308 and accumulated error value 310 will likely be zero or small non-zero values.
According to one embodiment, received signal s(t) 302 represents a multi-level signal such that output value 322 is selected by comparator 312 from more than two distinct values, based on the corrected signal 306 . In other words, the original baseband signal from which received signal 302 is based may have been encoded to be one of more than two signal levels for any particular sample period. For example, the original baseband signal may have been encoded to be −0.75, −0.25, +0.25, or +0.75 in any particular sample period.
In this example, comparator 312 compares corrected signal 306 to three decision values: −0.5, 0, and +0.5 and, based on the result of the comparison, selects one of four distinct values as the output value 322 . If corrected signal 206 is less than −0.5, then the comparator outputs −0.75 as output value 322 . If corrected signal 206 is between −0.5 and 0, then the comparator outputs −0.25 as output value 322 . Similarly, comparator outputs +0.25 as output value 322 if corrected signal 306 is between 0 and +0.5, and outputs +0.75 as output value 322 if corrected signal 306 is greater than +0.5. This example illustrates that the invention is not limited to the decoding of bi-level signals, and does not in any way restrict the invention to the specific decision values and output values in the example.
According to another embodiment, other methods of reducing DC offset noise is applied to received signal s(t) 302 before received signal 302 is processed by decoding system 300 . For example, signal 302 may be passed through a high-pass filter before being processed by system 300 . A high pass filter with a low cutoff may center the operation of system 300 around zero, thereby making implementation simpler.
In another embodiment, range limiting may be applied to prevent decoding system 300 from entering a false lock state. Range limiting may be implemented in accumulator 316 to limit the output value to a predetermined tracking range. Such range limiting may prevent false lock states since accumulated error value 310 will be less than the minimum decision distance.
In one embodiment, system 300 may be controlled by a gain constant that controls the loop gain and therefore the effective bandwidth of the loop in system 300 . This may be included within accumulator 316 , or can be achieved by placing a gain constant (not depicted) between accumulator 316 and subtractor 320 . The gain constant may be a multiplier or a shift function.
Using a Training Sequence in Decoding Bursty Signals
Sometimes, received signal s(t) 302 may be bursty in that received signal 302 contains data only in certain burst periods. A bursty received signal 302 does not contain any data in time periods between the burst periods. One problem encountered in decoding a bursty received signal 302 is that the DC offset exhibited by received signal 302 at the end of a first burst period may be different from the DC offset exhibited by received signal 302 at the beginning of a second burst period that immediately follows the first burst period. Such a sudden jump in DC offset may result in decoding system 300 taking a long time to re-stabilize and making decoding errors during the time of re-stabilization. According to one embodiment, received signal 302 contains a training sequence at the beginning of a burst period, thereby allowing decoding system 300 to stabilize before non-training sequence data is decoded.
The training sequence is a predetermined data sequence that is known to decoding system 300 . For example, the training sequence may be a string of zeros. A training sequence comparator (not depicted) in decoding system 300 compares the training sequence in received signal 302 to the predetermined data sequence (e.g., 0, 0, 0, . . . ) and determines the difference between the training sequence in received signal 302 and the predetermined data sequence. This difference between the training sequence in received signal 302 and the predetermined data sequence is accumulated as an accumulated training sequence error value in a training sequence error accumulator (not depicted). The accumulated training sequence error value is loaded into accumulator 316 at the end of the training sequence. As a result, at the end of the training sequence and the beginning of data in a burst period, accumulator 316 will output an accumulated error value 310 that has already been adjusted to the DC offset exhibited by received signal 302 . Consequently, decoding system 300 can quickly stabilize, thereby minimizing or eliminating any decoding errors that may have resulted from the differences in DC offsets exhibited by received signal 302 in two consecutive burst periods.
In one embodiment, the training sequence is also known to occur at certain times. In an alternative embodiment, the time at which the training sequence occurs is not known beforehand. Decoding system 300 includes an additional training sequence detector (not depicted) that detects the beginning and end of the training sequence.
In one embodiment, the training sequence contains the highest expected signal level and the lowest expected signal level of received signal 302 , which facilitates the fast stabilization of decoding system 300 . For example, if the expected signal levels of received signal 302 are −0.75, −0.25, +0.25, and +0.75, then the training sequence contains only the signal levels of −0.75 and +0.75.
In one embodiment, the training sequence has an average signal value of zero, which reduces gain error sensitivity.
In one embodiment, the training sequence detector may be shared by the decoder for the real component of a complex baseband signal and the decoder for the imaginary component of the complex baseband signal. | A method and apparatus for decoding a baseband signal of a radio signal removes, from the baseband signal, low-frequency and long-term noise that increases the possibility of decoding errors. The removal of low-frequency and long-term noise is performed by accumulating differences between the actual signal levels of the baseband signal and the expected signal levels for the baseband signal and subtracting the accumulated difference from the baseband signal before decoding. In one scheme, the baseband signal contains a predetermined training sequence of signal levels, where the differences between the actual signal levels of the baseband signal and the expected signal levels for the predetermined training sequence are accumulated. At the end of the training sequence, the accumulated training sequence difference is used as the accumulated difference and subtracted from the baseband signal, thereby providing stable operation for decoding signal levels that follow the training sequence. | 7 |
BACKGROUND
[0001] Hydrocarbon drilling and recovery systems employ strings of tubulars that extend downhole. Often times one or more of the tubulars include openings. The openings may be selectively exposed to allow downhole fluids to pass into the string of tubulars. In some cases, a sliding sleeve is deployed to expose the openings. More specifically, the string of tubulars is positioned downhole and, at a desired time, the sliding sleeve is shifted to expose the openings. Once opened, the sleeve may be locked in place by a locking mechanism. The lock allows, for example, coiled tubing to be run downhole through the tubular without inadvertently closing the sleeve. Once locked, the sleeve may not be closed. Accordingly, improvements in sleeve locking and retaining devices are well received by the industry.
SUMMARY
[0002] A tubular assembly includes a turbular member having at least one opening, and a sleeve slidingly mounted relative to the tubular member. The sleeve is shiftable between an open configuration, in which the at least one opening is exposed, and a closed configuration, in which the at least one opening is covered by the sleeve. A degradable locking member is mounted relative to one of the turbular and the sleeve. The degradable locking member selectively retains the sleeve in the open configuration. The degradable locking member is configured to degrade when exposed to a downhole fluid allowing the sleeve to be shifted to the closed configuration.
[0003] A resource extraction system includes an uphole portion having at least a platform, a wellbore formed in a formation, and a tubular assembly extending down the wellbore into the formation. The tubular assembly includes a turbular member including at least one opening and a sleeve slidingly mounted relative to the tubular member. The sleeve is shiftable between an open configuration, in which the at least one opening is exposed, and a closed configuration, in which the at least one opening is covered by the sleeve. A degradable locking member is mounted relative to one of the turbular and the sleeve. The degradable locking member selectively retains the sleeve in the open configuration. The degradable locking member is configured to degrade when exposed to a downhole fluid allowing the sleeve to be shifted to the closed configuration.
[0004] A method of operating a downhole slidable sleeve includes running a tubular assembly including at least one tubular having one or more openings covered by a slidable sleeve into a wellbore, shifting the slidable sleeve relative to the at least one tubular from a closed configuration to an open configuration exposing the one or more openings to a downhole fluid, locking the slidable sleeve in the open configuration with a degradable locking member, and exposing the degradable locking member to a downhole fluid causing the degradable locking member to degrade.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Referring now to the drawings wherein like elements are numbered alike in the several Figures:
[0006] FIG. 1 depicts a resource extraction system including a tubular assembly having a slidable sleeve with a degradable locking member, in accordance with an aspect of an exemplary embodiment;
[0007] FIG. 2 depicts the tubular assembly of FIG. 1 with the slidable sleeve in a closed configuration;
[0008] FIG. 3 depicts the tubular assembly with the slidable sleeve locked in an open configuration through the degradable locking member of FIG. 1 ;
[0009] FIG. 4 depicts a degradable locking member, in accordance with an aspect of an exemplary embodiment;
[0010] FIG. 5 depicts a degradable locking member, in accordance with another aspect of an exemplary embodiment; and
[0011] FIG. 6 depicts a degradable locking member, in accordance with yet another aspect of an exemplary embodiment.
DETAILED DESCRIPTION
[0012] A resource extraction system, in accordance with an exemplary embodiment, is indicated generally at 2 , in FIG. 1 . Resource extraction system 2 includes an uphole system 4 operatively connected to a downhole system 6 . Uphole system 4 may include a platform 7 that supports pumps 8 that aid in completion and/or extraction processes as well as fluid storage 10 . Fluid storage 10 may contain a completion fluid that is introduced into downhole system 6 . Downhole system 6 may include a downhole string of tubulars 20 that is extended into a wellbore 21 formed in formation 22 . A well casing 23 extends down wellbore 21 to provide stability. Downhole string of tubulars 20 may include a tubular 24 and a slidable sleeve 30 . Slidable sleeve 30 may be selectively shifted from a closed configuration ( FIG. 2 ) to an open configuration ( FIG. 3 ) exposing a plurality of openings 33 formed in turbular 24 . Openings 33 allow fluid to pass from wellbore 21 into an interior portion 35 of tubular string 20 and vice versa. In the exemplary embodiment shown, slidable sleeve 30 is arranged radially inwardly of tubular 24 . However, it should be understood that the relative position of slidable sleeve 30 and tubular 24 may vary.
[0013] In accordance with an aspect of an exemplary embodiment, a degradable locking member 40 retains slidable sleeve 30 in the open configuration. In the exemplary embodiment shown, locking member 40 is positioned radially outwardly of an outer surface (not separately labeled) of slidable sleeve 30 . When in the open configuration, degradable locking member 40 nests within an annular groove 44 formed in the outer surface of slidable sleeve 30 . When nested within annular groove 44 , slidable sleeve 30 is prevented from shifting from the open configuration. In this manner, operators may introduce components, such as various tools, coiled tubing and the like, into downhole tubular string 20 without inadvertently shifting slidable sleeve 30 to the closed configuration. In previous systems, slidable sleeve 30 was forever prevented from being closed. In accordance with the exemplary embodiment, degradable locking member 40 will, over time, mechanically and/or chemically degrade. When degraded to a particular degree, slidable sleeve 30 may be shifted against degradable locking member 40 . Further shifting will cause degradable locking member 40 to release. At such time, slidable sleeve 30 may be freely shifted from the open configuration to the closed configuration.
[0014] In accordance with one aspect of an exemplary embodiment, degradable locking member 40 may take the form of a degradable snap ring 50 , illustrated in FIG. 4 . Degradable snap ring 50 extends from a first end 52 to a second end 54 through a degradable intermediate portion 56 . First end 52 may be spaced from second end 54 defining a discontinuity 58 . In accordance with another aspect of an exemplary embodiment, locking member 40 may take the form of a body lock ring 68 , illustrated in FIG. 5 . Body lock ring 68 may include a plurality of teeth 69 that meshingly engage with another plurality of teeth 71 formed on an outer surface (not separately labeled) of a slidable sleeve 74 . In accordance with yet another aspect of an exemplary embodiment, degradable locking member 40 may take the form of a collet 80 arranged radially outwardly of tubular 24 . Collet 80 includes a degradable locking portion 82 that, once degraded, allows slidable sleeve 30 to return to a closed configuration.
[0015] At this point, it should be understood that degradable locking member 40 may be formed in whole, or in part, from a material that disintegrates when exposed to downhole fluids. As will be discussed more fully below, degradable locking member 40 may be provided with a coating that may delay disintegration of degradable locking member 40 for a period of time. As will be discussed more fully below, coatings and underlying body materials may take on a variety of forms.
[0016] In accordance with an aspect of an exemplary embodiment, degradable locking member 40 may be formed from materials that are degradable by exposure to a variety of fluids capable of being pumped, present, or delivered downhole such as water, acid, oil, etc. The degradable material could be a metal, a composite, a polymer, etc., or any other material that is suitably degradable and that can withstand the loads during run-in, etc. In one embodiment, the degradable locking member 40 may be manufactured from a high strength controlled electrolytic metallic material and is degradable by brine, acid, or aqueous fluid.
[0017] That is, materials appropriate for the purpose of degradable locking member 40 described herein are lightweight, high-strength metallic materials. Examples of suitable materials, e.g., high strength controlled electrolytic metallic materials, and their methods of manufacture are given in United States Patent Publication No. 2011/0135953 (Xu, et al.), which Patent Publication is hereby incorporated by reference in its entirety. These lightweight, high-strength, selectably and controllably degradable materials include fully-dense, sintered powder compacts formed from coated powder materials that include various lightweight particle cores and core materials having various single layer and multilayer nanoscale coatings. These powder compacts are made from coated metallic powders that include various electrochemically-active (e.g., having relatively higher standard oxidation potentials) lightweight, high-strength particle cores and core materials, such as electrochemically active metals, that are dispersed within a cellular nanomatrix formed from the various nanoscale metallic coating layers of metallic coating materials, and are particularly useful in borehole applications.
[0018] Suitable core materials include electrochemically active metals having a standard oxidation potential greater than or equal to that of Zn, including Mg, Al, Mn or Zn or alloys or combinations thereof. For example, tertiary Mg—Al—X alloys may include, by weight, up to about 85% Mg, up to about 15% Al and up to about 5% X, where X is another material. The core material may also include a rare earth element such as Sc, Y, La, Ce, Pr, Nd or Er, or a combination of rare earth elements. In other embodiments, the materials could include other metals having a standard oxidation potential less than that of Zn. Also, suitable non-metallic materials include ceramics, glasses (e.g., hollow glass microspheres), carbon, or a combination thereof. In one embodiment, the material has a substantially uniform average thickness between dispersed particles of about 50 nm to about 5000 nm. In one embodiment, the coating layers may be formed from Al, Ni, W or Al 2 O 3 , or combinations thereof. In one embodiment, the coating may be a multi-layer coating, for example, comprising a first Al layer, a Al 2 O 3 layer, and a second Al layer. In some embodiments, the coating may have a thickness of about 25 nm to about 2500 nm.
[0019] These powder compacts provide a unique and advantageous combination of mechanical strength properties, such as compression and shear strength, low density and selectable and controllable corrosion properties, particularly rapid and controlled dissolution in various borehole fluids. The fluids may include any number of ionic fluids or highly polar fluids, such as those that contain various chlorides. Examples include fluids comprising potassium chloride (KCl), hydrochloric acid (HCl), calcium chloride (CaCl 2 ), calcium bromide (CaBr 2 ) or zinc bromide (ZnBr 2 ). For example, the particle core and coating layers of these powders may be selected to provide sintered powder compacts suitable for use as high strength engineered materials having a compressive strength and shear strength comparable to various other engineered materials, including carbon, stainless and alloy steels, but which also have a low density comparable to various polymers, elastomers, low-density porous ceramics and composite materials.
[0020] While one or more embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation. | A tubular assembly includes a turbular member having at least one opening, and a sleeve slidingly mounted relative to the tubular member. The sleeve is shiftable between an open configuration in which the at least one opening is exposed and a closed configuration in which the at least one opening is covered by the sleeve. A degradable locking member is mounted relative to one of the turbular and the sleeve. The degradable locking member selectively retains the sleeve in the open configuration. The degradable locking member is configured to degrade when exposed to a downhole fluid allowing the sleeve to be shifted to the closed configuration. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
BACKGROUND OF THE INVENTION
This invention relates to a fixture for a milling machine. In particular, the invention relates to a chip guard and the milling machine equipped with the chip guard.
It is considered good practice to shield machine operators from workplace hazards. The Occupational Safety & Health Administration (OSHA) of the U.S. Department of Labor, in Standard No. 1910.22, requires that one or more methods of machine guarding be provided to protect operators from hazards associated with machine tool operation. For these reasons, a variety of guard designs have been developed. The background art is characterized by the inventions described in U.S. Pat. Nos. 1,527,998; 1,563,887; 3,703,124; 3,837,383; 4,043,701; 4,126,081; 4,132,497; 4,162,647; 4,290,717; 4,543,012; 4,543,021; 4,552,494; 4,884,927; 5,103,541; 5,218,887; and 5,479,837; the disclosures of which patents are incorporated herein as if fully set forth.
Serpico in U.S. Pat. No. 1,527,998 discloses a protective guard for a router. This invention is limited in that it must be attached to the router rod portion of the router. The invention is further limited in that the glass guard can only be pivoted about a horizontal axis.
Wiespetat in U.S. Pat. No. 1,563,887 discloses a drill press guard. This invention is limited in that the guard must be attached to the feed rack or quill of the drill press.
Smith et al. in U.S. Pat. No. 3,703,124 disclose a machine tool guard and/or safety guard. This invention is limited in that it is attached to a slot in the table of the machine tool and does not effectively protect the user when the tool is raised above the surface of the table.
Ko in U.S. Pat. No. 3,837,383 discloses a dust collector and safety guard. This invention is limited in that it is attached to the machine tool by means of a flange that must be fixed to the machine.
Jaeger in U.S. Pat. No. 4,043,701 discloses a safety shield assembly. This invention is limited in that it is attached to the machine tool by means of a bracket.
Zdeb in U.S. Pat. No. 4,126,081 discloses a safety shield for a machine tool. This invention is limited in that the safety shield must be attached to the quill of the milling machine. The invention is further limited in that the panels of the shield can only be pivoted about a horizontal axis.
Weller et al. in U.S. Pat. No. 4,132,497 disclose drilling machines and guards therefor. This invention is limited in that it must be attached to the quill of a vertical milling machine.
Aslen in U.S. Pat. No. 4,162,647 discloses a guard for a milling machine that comprises a combination of rods and blocks supporting guard panels relative to the milling tool. In one embodiment, the invention of Aslen comprises a plurality of mounting bars that are attached to the dovetail of a milling machine ram by means of clamping blocks secured in place with clamping bolts. Each mounting bar supports a pair of mounting blocks from which support rods extend into support blocks. A mounting rod extends downward from each support block to which an attachment block is secured. Each pair of support blocks a guard panel. This invention is limited in that multiple mounting bars, mounting blocks, support blocks and attachment blocks are required. The requirement for multiple mounting bars and blocks means that the device cannot be attached to the end of the dovetail when the ram is moved backward leaving only a short portion of the dovetail forward of the turret, which is normally the case. The invention is further limited in that planar guard panels are provided, which panels can only be pivoted about a horizontal axis.
Aslen in U.S. Pat. No. 4,290,717 discloses machinery safety guards. This invention is limited in that it must be attached to the barrel of a vertical milling machine.
Adler in U.S. Pat. No. 4,543,021 discloses a safety shield for a machine tool. This invention is limited in that it must be connected by a series of rods, links, knuckle joints, etc. to an existing hole in a Bridgeport type milling machine.
Wix in U.S. Pat. No. 4,552,494 discloses a collapsible safety shield for a vertical drill press. This invention is limited in that it must be attached to the drill housing.
Menker in U.S. Pat. No. 4,884,927 discloses a shield unit for a machine tool. This invention is limited in that it must be attached to the machine tool's spindle adjustment rod.
Ferletic in U.S. Pat. No. 5,103,541 discloses a milling machine stop bar for use with reversing tapping attachments. The stop-bar is clamped onto the ram of the milling machine. This invention is limited in that it does not provide a guard for protection of the machine operator.
Ziobro in U.S. Pat. No. 5,218,887 discloses a drill chuck and revolving spindle guard. This invention is limited in that the safety shield must be attached to the quill of milling machine. The invention is further limited in that the guard cannot be repositioned vertically.
Kyle in U.S. Pat. No. 5,479,837 discloses a guard for a channel bed press. This invention is limited in that it attaches to the rear channel on the channel bed of such a press.
The inventions in the related art exhibit one or more limitations. Many related art milling machine guards attach to the quill, quill housing, barrel, etc. of the machine, parts which are tilted from the vertical or moved relative to the workpiece during some machine operations. Under these conditions, the related art guards can interfere with the operations and the guards can be rendered less effective by their orientation or distance from the workpiece. The related art fixtures that attach to the dovetail of the milling machine ram are overly mechanically complex and, hence, expensive to manufacture and difficult to use, not designed to be attached to the end of the dovetail or fail to guard the operator. None of the related art fixtures can be moved out of the way when not required. Furthermore, none of the related art fixtures direct oil to the cutting face.
BRIEF SUMMARY OF THE INVENTION
The purpose of the invention is to deflect chips that are produced during a milling operation and generally to facilitate the milling operation and protect the machine operator from rotating parts, flying chips and sparks. One advantage of the invention is that it is mechanically simple (comprises relatively few parts) and simple to use. Another advantage is that one or more of the guarding means (arms and guards) can be rotated (swung) out of the way when not required. Another advantage of the invention is that the guard is attached to the milling machine at a point that does not move when the quill moves.
One object of the invention is to deflect chips produced during a milling operation. Another object of the invention is to shield a machine operator during a milling operation. A further object is to direct oil to a cutting face.
The invention is an apparatus for guarding an operator from hazards produced at the point of operation of a machine tool. The apparatus comprises means for attaching a fixture to the dovetail of the ram of a milling machine (e.g., a Bridgeport vertical milling machine), said means for attaching having a first end and a second end; a swing arm attached to one of said ends; and guarding means attached to said swing arm. In some embodiments, a second swing arm attached to the other of said ends supports a second guarding means or a tube that carries oil to the work piece.
In use, the invention is operated by sliding a mounting bracket onto the dovetail of a ram of a milling machine and by securing the mounting bracket on the dovetail by means of a vertical set screw that is threaded into the mounting bracket. Each of the arms of the device are then swung forward (and raised or lowered, if necessary) to position the guards between the machine operator and the point of operation. Each of the arms is then secured in place by means of a horizontal set screw on the mounting bracket. For the purposes of this disclosure, the term “vertical” means generally in a plane transverse to the longitudinal axis of the bracket with a general up and down orientation and the term “horizontal” means generally in a plane parallel to the longitudinal axis of the bracket with a general side to side or back to front orientation.
In broad terms, a preferred embodiment of the apparatus is a device for deflecting chips produced by operation of a milling machine, said milling machine having a ram with a dovetail, said device comprising: a bracket that is slidably mountable on said dovetail, said bracket having a first end and a second end; a first swing arm that is rotatably attachable to said bracket adjacent said first end; a second swing arm that is rotatably attachable to said bracket adjacent said second end; and a pair of deflectors, one of which is attachable (preferably slidably attachable) to said first swing arm and the other of which is attachable (preferably slidably attachable) to said second swing arm.
Another preferred embodiment of the invention is a point of operation guard for use on a milling machine having a ram on which the head of the milling machine is mounted, said ram being attached to the column of the milling machine by means of a dovetail slide, said dovetail slide having a mortise portion that is attached to said column and a tenon portion that is attached to said ram, said point of operation guard comprising: a body having a mortise therein that is slidably mountable on said tenon portion, said body having a first end and a second end; a first arm that is rotatably attached to said body adjacent said first end; and a first deflector attached to said first arm. In an alternative embodiment the above point of operation guard also comprises: a second arm that is rotatably attached to said body adjacent said second end; and a second deflector attached to said second arm.
In another alternative embodiment, the above point of operation guard also comprises: a solid thumb screw that is screwed into a first threaded hole in said body and that impinges on said tenon portion when said body is mounted on said tenon portion. In another alternative embodiment, the above point of operation guard also comprises: a first nylon- or brass-tipped thumb screw that is screwed into a second threaded hole in said body and that has a first nylon or brass tip that impinges on said first arm when said arm is inserted through a first unthreaded hole in said body; and a second nylon- or brass-tipped thumb screw that is screwed into a third threaded hole in said body and that has a second nylon or brass tip that impinges on said second arm when said arm is inserted through a second unthreaded hole in said body. In another alternative embodiment, the invention is the above point of operation guard wherein said first deflector and said second deflector each comprise a flexible plastic member having a longitudinal hole therein; and wherein said first arm and said second arm are fitted through each hole. In another alternative embodiment, the invention is the above point of operation guard wherein an end of each arm that protrudes through said unthreaded holes in said body is fitted with a cap made of a resilient material (e.g., rubber). In another alternative embodiment, the invention is the above point of operation guard wherein said body is comprised of two pieces, with each piece forming a part of the mortise and wherein said pieces are connected by a bolt that is used to adjust the effective width of said mortise.
In another preferred embodiment, the invention is a milling machine comprising the above apparatus for guarding an operator or point of operation guard. The milling machine further comprises a base, a column resting on said base, said column supporting a turret having a tenon portion of a dovetail slide, a table resting on a knee which rests on a pedestal that extends upward from said base, a ram having a mortise portion of the dovetail slide, and a head attached to said ram, said head having a quill and a spindle.
Further aspects of the invention will become apparent from consideration of the drawings and the ensuing description of preferred embodiments of the invention. A person skilled in the art will realize that other embodiments of the invention are possible and that the details of the invention can be modified in a number of respects, all without departing from the inventive concept. Thus, the following drawings and description are to be regarded as illustrative in nature and not restrictive.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The features of the invention will be better understood by reference to the accompanying drawings which illustrate presently preferred embodiments of the invention. In the drawings:
FIG. 1 is an elevation view of a milling machine with a preferred embodiment of the point of operation guard installed.
FIG. 2 is a perspective view of a first preferred embodiment of the device before it has been attached to a milling machine.
FIG. 3 is a perspective view of a second preferred embodiment of the device before it has been attached to a milling machine.
FIG. 4 is a perspective view of a preferred embodiment of the mounting bracket.
The following reference numerals are used to indicate the parts and environment of the invention on the drawings:
8 milling machine
10 chip deflector
12 mounting bracket
14 first pivot arm
15 first rubber cap
16 first plastic guard
18 second pivot arm
19 second rubber cap
20 second plastic guard
22 mortise
24 first part
26 second part
28 threaded rod
30 tenon
31 centerline
32 ram
34 vertical thumb screw
36 first vertical segment
38 first horizontal thumb screw
40 second vertical segment
42 second horizontal thumb screw
44 first horizontal portion
46 second horizontal portion
48 first curved portion
50 second curved portion
52 source of oil
54 first vertical unthreaded hole
56 first horizontal hole
58 first end
60 second vertical unthreaded hole
62 first horizontal hole
64 second end
66 vertical threaded hole
70 first unthreaded portion
72 first spring
74 second unthreaded portion
76 second spring
80 first horizontal threaded hole
82 second horizontal threaded hole
84 first tubular portion
86 first guard portion
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, milling machine 8 is shown equipped with chip deflector 10 . Chip deflector 10 is mounted on tenon 30 portion of ram 32 by means of mounting bracket 12 . First pivot arm 14 extends downward from mounting bracket 12 and then horizontally, supporting first plastic guard 16 . Mounting bracket 12 is attached to tenon 30 portion at a location that positions plastic guard 16 between the center line 31 of the spindle of milling machine 8 (and, hence, the point of operation) and the machine operator (not shown).
Referring to FIG. 2, a first preferred embodiment of chip deflector 10 is illustrated. Chip deflector 10 comprises mounting bracket 12 , first pivot arm 14 which supports first plastic guard 16 and second pivot arm 18 which supports second plastic guard 20 . Mounting bracket 12 is configured to provide mortise 22 portion of a dovetail joint. In the embodiment illustrated in FIG. 1, mounting bracket comprises two parts: first part 24 and second part 26 . The width of mortise 22 is adjustable by means of threaded rod 28 which is screwed into threaded holes in first part 24 and second part 26 of mounting bracket 12 . In an alternative embodiment, mounting bracket 12 is configured to provide a mortise having an adjustable width in accordance with the design illustrated in FIG. 3 of U.S. Pat. No. 5,103,541.
Mortise 22 portion of mounting bracket 12 slides onto tenon 30 portion of the dovetail slide that attaches ram 32 to the column of a vertical milling machine. When mounting bracket 12 is placed on tenon 30 , it is moved to a position that places center line 31 of the milling machine spindle between plastic guards 16 and 20 and vertical thumb screw 34 is tightened to secure mounting bracket 12 to ram 32 . Then, first vertical segment 36 of first pivot arm 14 is moved up or down to appropriately position first plastic guard 16 , and fit horizontal thumb screw 38 is tightened to secure first plastic guard 16 in position. Finally, second vertical segment 40 of second pivot arm 18 is moved up or down to appropriately position second plastic guard 20 , and second horizontal thumb screw 42 is tightened to secure second plastic guard 20 in position. In a preferred embodiment, the upper end of first pivot arm 14 is fitted with first rubber cap 15 , and the upper end of second pivot arm 18 is fitted with second rubber cap 19 . In a preferred embodiment, horizontal thumb screws 38 and 42 have nylon or brass tips. In a preferred embodiment, a product name, such as Batwing™ is written on the outside surface of first plastic guard 16 .
Referring to FIG. 3, a preferred embodiment of mounting bracket 12 is illustrated. Mounting bracket 12 is comprised of two parts that form mortise 22 . Mounting bracket 12 has first vertical unthreaded hole 56 and first horizontal hole 56 adjacent first end 58 , second vertical unthreaded hole 60 and second horizontal hole 62 adjacent second end 64 and first vertical threaded hole 66 below mortise 22 . Mounting bracket 12 is held in position on tenon 30 portion by a first vertical thumbscrew that is screwed into first vertical threaded hole 66 and that impinges on tenon 30 . First unthreaded portion 70 of first horizontal hole extends through first vertical unthreaded hole 54 , and first spring 72 is compressed in first unthreaded portion 70 to the extent that it is biased against first arm 14 and first arm 14 resists rotation and up and down movement. Second unthreaded portion 74 of second horizontal hole 62 extends through second vertical unthreaded hole 60 and second spring 76 is compressed in second unthreaded portion 74 to the extent that it is biased against second arm 18 , and second arms 18 resists rotation and up and down movement. In this embodiment, each of the parts of mounting bracket 12 has a horizontal threaded hole therein, the parts being held together by a threaded rod (not shown) that is screwed into first horizontal threaded hole 80 and second horizontal threaded hole 82 . In another preferred embodiment, mounting bracket 12 is constructed in a single piece. In this embodiment, the width of mortise 22 is not adjustable.
In a further preferred embodiment, each of the pivot arms comprises a horizontal portion, e.g., first horizontal portion 44 and second horizontal portion 46 , at least a portion of which is curved in a horizontal plane in the shape of a segment of a circle. In this embodiment, first plastic guard 16 is supported by first curved portion 48 , and second plastic guard 20 is supported by second curved portion 50 .
In another preferred embodiment, first plastic guard 16 and second plastic guard 20 each comprise a flexible plastic member having a longitudinal hole there through. In this embodiment, first pivot arm 14 and second pivot arm 18 are fitted through each hole. In an alternative embodiment, first pivot arm 14 and/or second pivot arm 18 support planar safety shields or guard panels similar to those disclosed in U.S. Pat. Nos. 4,043,701, 4,162,627, 4,543,021, 4,884,927 or 5,479,837.
Referring to FIG. 4, an alternative embodiment of chip deflector 10 is illustrated. In this embodiment, only one of the pivot arms (e.g., first pivot arm 14 ) supports a plastic guard (e.g., first plastic guard 16 ). The second pivot arm (e.g., second pivot arm 18 ) is a length of tubing that carries oil from source of oil 52 , e.g., a rubber or plastic tube carrying oil from a reservoir or pump (not shown), to the cutting surface. In this embodiment, plastic guard 16 has first tubular portion 84 and first guard portion 86 attached to first tubular portion 84 , plastic guard 16 being attached to first pivot arm 14 by horizontal portion 44 of first pivot arm 14 extending through first tubular portion 84 .
The best mode of the invention involves fabricating mounting bracket 12 from aluminum and pivot arms 14 and 18 from steel and first and second guards 16 and 20 from extruded thermoplastic. Conventional thumb screws, threaded rod or bolts and rubber tips are used.
Operation of the invention involves rotation of part 24 relative to part 26 until the width of mortice 22 is slightly wider than the width of tenon 30 portion. Then mounting bracket 12 is slipped on to tenon 30 and vertical thumb screw is tightened. Next, pivot arms 14 and 18 are rotated forward and toward the work area and secured in position with horizontal thumb screws 38 and 42 . When chip guard 10 is not required, pivot arms 14 and 18 are pivoted about vertical axes back away from the work area.
Many variations of the invention will occur to those skilled in the art. Some variations include a one-piece mounting bracket. Other variations call for a multiple-piece mounting bracket. All such variations are intended to be within the scope and spirit of the invention. | An apparatus for guarding an operator from hazards produced at the point of operation of a machine tool. The apparatus comprises a mounting bracket for attaching the fixture to the dovetail of the ram of a milling machine (e.g., a Bridgeport vertical milling machine), the mounting bracket having a first end and a second end; a swing arm attached to one of the ends; and a guard attached to the swing arm. In some embodiments, a second swing arm attached to the other of the ends supports a second guard or a tube that carries oil to the work piece. | 8 |
FIELD OF THE INVENTION
The present invention relates to a doctor arrangement for roll presses which includes a web transfer device which lies against the barrel surfaces of each of the respective rolls or against a wire mounted on the barrel surface.
BACKGROUND OF THE INVENTION
A roll press generally includes two mutually coacting press rolls that define a press roll nip therebetween. The rolls are arranged in a trough into which a suspension of material, such as a pulp suspension, is delivered. The rolls have liquid pervious barrel surfaces and the suspension is de-watered by pressing the liquid through these surfaces with the aid of an overpressure. Final de-watering of the suspension to a desired dry content of the material is achieved in the nip between the rolls. The barrel surfaces of the press rolls comprise perforated sheet metal attached to a roll body. In order to obtain a sufficiently large capacity, the combined open area of the holes must be large while, at the same time, the holes must be small so that fibers will not accompany the liquid through the holes. Wires may be mounted onto the barrel surfaces of the rolls for this purpose. Downstream of the roll nip a doctor arrangement is located which functions to remove the de-watered pulp web from the rolls or from the wires mounted thereon. The doctor arrangement includes a web transfer device for each roll. In the past, the web transfer device has comprised a doctor beam that includes a doctor blade for abutment with the barrel surface of the roll or with the wire.
The present invention is based upon a problem which was encountered with doctor beams and doctor blades. This problem is one of maintaining the doctor blade and the wire surface at a particular distance apart, and is particularly manifested by the greater lengths of such roll presses. With the intention of obtaining maximum possible rigidity, the doctor beam has been provided with a box-like construction. The boxlike construction, coupled with the temperature differences of the different plates in the beam structure, make it impossible to retain the doctor blade setting. Consequently, the doctor blade has been placed firmly against the roll in practice, in order to reduce fiber transfer in the pulp. In the case of presses that do not include wires, this practice has been more or less successful, and results in lower fiber transfer. In the case of rolls that are fitted with wires, however, it has not been possible to adjust the doctor blade to a zero setting without the risk of cutting the wire to pieces.
An object of the present invention is to thus eliminate the aforesaid problem and to enable the doctor blades to optimally abut the press rolls.
SUMMARY OF THE INVENTION
In accordance with the present invention, this and other objects have now been realized by the invention of apparatus for handling a web comprising a pair of juxtaposed press rolls including an outer surface and providing a nip therebetween for providing the web, a coarse shredder trough disposed above the nip for receiving the web from the nip, web transfer means for transferring the web from the outer surfaces of the pair of juxtaposed press rolls, and web transfer means comprising a plurality of doctor sections extending longitudinally of the pair of juxtaposed press rolls and a plurality of doctor blades attached to the plurality of doctor sections and extending in abutment with the outer surfaces of the pair of juxtaposed press rolls, the web transfer means being supported by the coarse shredder trough by a pair of adjustable support members and a pair of pivot shafts for pivotable movement of said pair of adjustable members. In accordance with a preferred embodiment, the outer surfaces of the pair of juxtaposed press rolls comprise wire means mounted on the outer surface of the pair of juxtaposed press rolls.
In another embodiment, the pair of adjustable support members comprises a pair of bottle screws.
In accordance with one embodiment of the apparatus of the present invention, the pair of adjustable support members comprises spring means for resiliently mounting the pair of doctor sections relative to the outer surface of the pair of juxtaposed press rolls. In a preferred embodiment, the spring means are adjustable into a rigid position with respect to the outer surface of the pair of juxtaposed press rolls.
In accordance with another embodiment of the apparatus of the present invention, the apparatus includes suspension means connecting the coarse shredder trough with the plurality of doctor sections at the intersection of the plurality of doctor sections, the suspension means also connecting the plurality of doctor sections together at the intersection. Preferably, the suspension means is eccentrically pivotably connected to the plurality of doctor sections.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described in more detail with reference to the following detailed description which, in turn, refers to the accompanying drawings, in which
FIG. 1 is a side, elevational, cross-sectional view of the central part of a roll press equipped with a doctor arrangement above the roll nip in accordance with the present invention;
FIG. 2 is a side, elevational, enlarged view of a portion of the apparatus shown in FIG. 1;
FIG. 3 is a front, elevational view of a web transfer device in accordance with the present invention in a longitudinal plane through the press;
FIG. 3 a is a front, elevational, enlarged view of a portion of the apparatus shown in FIG. 3;
FIG. 3 b is a front, elevational, enlarged view of another embodiment of a portion of the apparatus shown in FIG. 3;
FIG. 3 c is a front, elevational, enlarged view of another embodiment of a large portion of the apparatus shown in FIG. 3;
FIG. 4 is a side, elevational, cross-sectional view of another embodiment of a doctor arrangement according to the present invention; and
FIG. 4 a is a front, elevational, enlarged view of a portion of the apparatus shown in FIG. 4 .
DETAILED DESCRIPTION
The roll press illustrated in FIG. 1 includes two rolls, 1 and 2 , which includes a perforated barrel, and which can also include a wire for allowing water pressed from the pulp to pass through. The roll 2 of rolls 1 and 2 can be moved laterally to adjust the setting of the roll nip 3 . The pulp is pressed upwardly towards the nip 3 between the rolls, 1 and 2 , where the pulp is de-watered, and is then pressed up from the nip 3 against a shredder screw 4 arranged in a coarse shredder trough 5 and extending parallel with the rolls. The shredder screw 4 disintegrates the pulp and conveys it axially out of the press. Each roll, 1 and 2 , is equipped with a respective web transfer device, 6 and 7 . The web transfer devices, 6 and 7 , are comprised of doctor sections 13 forming part of a modular system. Doctor blades 8 and 9 are provided at the bottom of respective doctor sections, for scraping respective roll surfaces or wire surfaces.
FIG. 2 is an enlarged view of that portion of the doctor arrangement belonging to the moveable roll 2 . Each doctor blade 9 is carried in the web transfer device 7 by a clamping strip 10 . Division of the web transfer device, doctor blades and clamping strips into modules 13 in the longitudinal direction of the press will best be seen from FIG. 3 . The doctor sections 13 are carried by the coarse shredder trough 5 by means of supports 14 , which in the case of the illustrated embodiment have the form of bottlescrews. As will be seen from FIGS. 2 and 3, a support element 14 is provided for each section 13 . Each support element 14 is pivotally mounted to an arm 15 fixed to the module 13 , and each arm is, in turn, pivotally mounted on a pivot shaft 16 . Because the doctor sections are pivotal about the pivot shaft 16 , the doctor blades, 8 and 9 , can be pressed against their respective roll surface, 1 and 2 , with an appropriate force, by shortening the support element 14 . That part of the doctor arrangement belonging to the moveable roll 2 includes a setting device 19 on each support element 14 , for changing the position of the support mounting at the coarse shredder trough 5 . This enables the individual modules to follow the moveable roll.
Also shown in FIG. 3 is a suspension device 20 provided at the boundary between two doctor sections 13 to thus connect the sections 13 end-to-end. The suspension can be made eccentric in accordance with FIG. 3 b with the aid of an eccentric pin 21 , or eccentric in accordance with FIG. 3 c with an eccentric sleeve 22 , 50 that adjustments can be made to the suspension points of the modules when necessary.
FIGS. 4 and 4 a illustrate an alternative embodiment of the supports 14 . In the case of this embodiment, instead of a bottle screw there is used, for example, a spring device that includes a compression spring 23 housed in a sleeve 24 . A setting rod 25 is connected to the sleeve 24 and loads the spring 23 downward in FIG. 4 a to an extent which depends on the position of the setting nut 26 . Upward movement of the setting rod 25 is limited by a stop screw 27 . This arrangement enables the doctor beam to be set positionally in four different ways. When the setting rod 25 is spaced from the stop screw 27 there will be spring abutment with the roll, and when the sleeve 24 is spaced from the trough plate 28 , i.e. the resting surface of the spring, the doctor beam can be moved away from the roll. On the other hand, in the absence of any space between the setting rod 25 and the stop screw 27 , there will be no spring abutment with the roll and if there is no distance between the sleeve 24 and the trough plate 28 , there will be no movement of the doctor beam away from the roll. This arrangement thus allows the support element 14 to operate in any one of four different ways, namely fully resilient, i.e. movement in both directions is permitted, resiliency against the roll, i.e. only movement towards the roll is permitted, resiliency away from the roll, i.e. movement is only permitted away from the roll, and full rigidity, i.e. no movement is permitted either towards or away from the roll.
The coarse shredder trough, which has previously been used solely to transport pulp, is also now used in accordance with the present invention as a reference point for the doctor sections. The coarse shredder trough already has the form of a beam construction, and the additional use of the trough to suspend the doctor sections means that the trough must be strengthened with stronger side-beams. The trough 5 thus becomes the rigid part, and transfer of the web is effected by doctor sections that are suspended individually from the trough 5 . The modular construction also enables the doctor arrangement to be used with presses of mutually different sizes, where the number of presses is the sole parameter. Because the doctor sections are thus short and constructed from a single plate, the temperature problems existing with traditional box constructions no longer occur. The doctor construction can be given any length along the press and no interspaces need be provided in order to compensate for thermal expansion. The system of modules means that each web transfer device will be thin but nevertheless strong, and will provide better geometrical conditions with respect to the roll body, i.e. provide better clearance angles to the roll, therewith reducing the risk of pulp packing beneath the doctor blades.
The doctor arrangement of the present invention thus provides significant improvement to the longest presses. The doctor beams previously used have required a center support fastened in the press trough. This construction required the press trough to be made stronger so as to prevent outward deflection of the press trough as a result of the trough pressure affecting the center support, i.e. the center of the doctor beam, thus causing the doctor blade to penetrate into the roll. Since this support can now be eliminated, the press trough can be calculated for a different outward deflection of the trough and is not restricted by the position or attitude of the doctor blade relative to the roll.
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. | Apparatus is disclosed for handling a web including a pair of juxtaposed press rolls providing a nip therebetween, a coarse shredder trough disposed above the nip to receive the web from the nip, and a doctor arrangement for transferring the web from the outer surfaces of the press roll including a doctor support extending longitudinally of the pair of press rolls and a plurality of doctor blades attached to the doctor supports and extending in abutment with the outer surfaces of the press rolls, the doctor arrangement being supported by the coarse shredder trough whereby the doctor blades form a rigid structure for the plurality of doctor blades. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority under 35 USC 119(e) from U.S. Provisional Application No. 60/309,078, filed Jul. 31, 2001, naming Walsh et al. as inventors, and titled “METHOD AND APPARATUS FOR COLLECTING CONDENSATE IN AN INTEGRATED FUEL CELL SYSTEM.” That application is incorporated herein by reference in its entirety and for all purposes.
BACKGROUND
The invention generally relates to a method and apparatus for collecting condensate from process streams in an integrated fuel cell system.
A fuel cell is an electrochemical device that converts chemical energy produced by a reaction directly into electrical energy. For example, one type of fuel cell includes a polymer electrolyte membrane (PEM), often called a proton exchange membrane, that permits only protons to pass between an anode and a cathode of the fuel cell. At the anode, diatomic hydrogen (a fuel) is reacted to produce protons that pass through the PEM. The electrons produced by this reaction travel through circuitry that is external to the fuel cell to form an electrical current. At the cathode, oxygen is reduced and reacts with the protons to form water. The anodic and cathodic reactions are described by the following equations:
H 2 →2H + +2 e − at the anode of the cell, and
O 2 +4H + +4 e − →2H 2 O at the cathode of the cell.
A typical fuel cell has a terminal voltage of up to about one volt DC. For purposes of producing much larger voltages, multiple fuel cells may be assembled together to form an arrangement called a fuel cell stack, an arrangement in which the fuel cells are electrically coupled together in series to form a larger DC voltage (a voltage near 100 volts DC, for example) and to provide more power.
The fuel cell stack may include flow field plates (graphite composite or metal plates, as examples) that are stacked one on top of the other. The plates may include various surface flow field channels and orifices to, as examples, route the reactants and products through the fuel cell stack. A PEM is sandwiched between each anode and cathode flow field plate. Electrically conductive gas diffusion layers (GDLs) may be located on each side of each PEM to act as a gas diffusion media and in some cases to provide a support for the fuel cell catalysts. In this manner, reactant gases from each side of the PEM may pass along the flow field channels and diffuse through the GDLs to reach the PEM. The PEM and its adjacent pair of catalyst layers are often referred to as a membrane electrode assembly (MEA). An MEA sandwiched by adjacent GDL layers is often referred to as a membrane electrode unit (MEU).
A fuel cell system may include a fuel processor that converts a hydrocarbon (natural gas or propane, as examples) into a fuel flow for the fuel cell stack. For a given output power of the fuel cell stack, the fuel flow to the stack must satisfy the appropriate stoichiometric ratios governed by the equations listed above. Thus, a controller of the fuel cell system may monitor the output power of the stack and based on the monitored output power, estimate the fuel flow to satisfy the appropriate stoichiometric ratios. In this manner, the controller regulates the fuel processor to produce this flow, and in response to the controller detecting a change in the output power, the controller estimates a new rate of fuel flow and controls the fuel processor accordingly.
The fuel cell system may provide power to a load, such as a load that is formed from residential appliances and electrical devices that may be selectively turned on and off to vary the power that is demanded by the load. Thus, the load may not be constant, but rather the power that is consumed by the load may vary over time and abruptly change in steps. For example, if the fuel cell system provides power to a house, different appliances/electrical devices of the house may be turned on and off at different times to cause the load to vary in a stepwise fashion over time. Fuel cell systems adapted to accommodate variable loads are sometimes referred to as “load following” systems.
Fuel cells generally operate at temperatures much higher than ambient (e.g., 50-80° C. or 120-180° C.), and the fuel and air streams circulated through the fuel cells typically include water vapor. For example, reactants associated with sulphonated fluorocarbon polymer membranes must generally be humidified to ensure the membranes remain moist during operation. In such a system, water may condense out of a process stream where the stream is cooled below its dew point. For example, if the anode and cathode exhaust streams are saturated with water vapor at the stack operating temperature, water will tend to condense from these streams as they cool after leaving the stack. Similarly, the humidity and temperature conditions of other process streams may also produce condensation. It may be desirable to remove condensate from a process stream in a fuel cell system process stream. As examples, such condensate can interfere with the flow of process streams, can potentially build to levels that can flood portions of the system, and can also cause problems if allowed to freeze (e.g., in an outdoor unit that is not in service).
The term “integrated fuel cell system” (also commonly referred to simply as “fuel cell system”) generally refers to a fuel cell stack that is coupled to components and subsystems that support the operation of the stack. For example, this could refer to a fuel cell stack that is connected to a power conditioning device that converts direct current from the fuel cell into alternating current similar to that available from the grid. It might also refer to a system equipped with a fuel processor to convert a hydrocarbon (e.g., natural gas, propane, methanol, etc.) into a hydrogen rich stream (e.g., reformate) for use in the fuel cell. An integrated fuel cell system may also include a control mechanism to automate at least some portion of the operation of the system. Integrated fuel cell systems may include a single controller common to the entire system, or may include multiple controllers specific to various parts of the system. Likewise, the operation of integrated fuel cell systems may be fully or partially automated. Also, an integrated fuel cell system may or may not be housed in a common enclosure.
There is a continuing need for integrated fuel cell systems and associated process methods designed to achieve objectives including the forgoing in a robust, cost-effective manner.
SUMMARY
The invention generally relates to a method and apparatus for collecting condensate from process streams in an integrated fuel cell system. In one aspect, the invention provides a water management subsystem for a fuel cell system. A gas conduit contains a gas at a first pressure (e.g., a fuel cell system process stream such as a cathode or anode reactant stream). A water tank in the system contains water at a certain level. The terms water tank and water collection tank are used interchangeably in this context, and generally refer to any vessel adapted to accumulate water in the system. The water tank has an inlet orifice below the water level. A drain conduit has a first end and a second end. The drain conduit is connected at the first end to the gas conduit, and the drain conduit is connected at the second end to the inlet orifice of the water tank. The water level and the inlet orifice have a vertical height of water between them corresponding to a head pressure greater than the first pressure. In this context, it will be appreciated that head pressure refers to the pressure exerted by a vertical column of water.
Various embodiments of the invention can include additional features, either alone or in combination. For example, the system can further include a water level sensor adapted to measure the water level. The water tank can have a second inlet orifice, and have a water supply (e.g., a municipal water line) connected to the second inlet orifice. A controller can be connected to the water level sensor, being adapted to feed water to the tank from the water supply when the sensor indicates the water level is below a predetermined threshold. For example, it may be desirable to keep a level of water in the tank such that the pressure at the inlet orifice leading to the drain conduit is greater than the pressure of the gas in the gas conduit (e.g., to prevent the gas from blowing into the water tank).
In some embodiments, a water level sensor is provided to measure the water level. The water tank has a drain (e.g., to the sewer), and a controller is connected to the water level sensor, such that the drain is opened when the sensor indicates the water level is above a predetermined threshold, and the drain is closed when the sensor indicates the water level is below a predetermined threshold.
An examples, the gas conduit can be an anode tailgas oxidizer, or a conduit associated with an anode tailgas oxidizer such as an inlet stream or exhaust stream. The gas conduit can also be an anode fuel outlet conduit of a fuel cell, or an anode fuel inlet conduit of a fuel cell.
In some embodiments, the water tank can include a gas inlet and a gas vent, wherein at least a portion of a cathode inlet air stream of a fuel cell is circulated through the water tank from the gas inlet to the gas vent. As an example, such an arrangement may be desired to continually flush the atmosphere in the water tank of any combustible components that might otherwise accumulate. In some embodiments, a cathode exhaust stream is circulated through the water tank instead. In some embodiments, such a gas vent is in fluid communication with an air inlet of an oxidizer. For example, the air purged from the water tank can be used to provide oxygen to the ATO.
In another aspect, the invention provides a water management subsystem for a fuel cell system that has a gas conduit containing gas at a first pressure. A water collection tank contains water and an atmosphere (i.e., the gas above the water level). The tank has an inlet orifice below the water level in the tank. The atmosphere of the tank has a second pressure. A drain conduit, having a first end and a second end, is connected at the first end to the gas conduit, and is connected at the second end to the inlet orifice of the water collection tank.
The water level and the inlet orifice have a vertical height of water between them corresponding to a head pressure, and the sum of the second pressure and the head pressure is greater than the first pressure. In this arrangement, condensate in the gas conduit is allowed to drain into the water tank through the drain conduit. Since the pressure at the tank inlet orifice is greater than that of the gas conduit, the gas in the gas conduit is not allowed to blow through the water tank.
In another aspect, the invention provides another water management subsystem for a fuel cell system. A gas conduit contains a gas at a first pressure. A water collection tank contains water and an atmosphere, the water having a level within the tank, the water collection tank having an inlet orifice above the water level, and the tank atmosphere having a second pressure. A drain conduit has a first end and a second end, and the drain conduit is connected at the first end to the gas conduit, and is connected at the second end to the inlet orifice of the water collection tank. A portion of the drain conduit forms a water trap bend (e.g., a “j-trap” or “p-trap” or other similar arrangement). The water trap bend contains water, and has a vertical height corresponding to a head pressure. The sum of the second pressure and the head pressure is greater than the first pressure.
In another aspect, the invention provides a method of water management for a fuel cell system, including at least the following steps: (1) flowing a fuel cell process stream containing liquid water through a gas conduit at a first pressure; (2) draining the liquid water from the gas conduit into a drain conduit; (3) draining the liquid water through the drain conduit into an inlet orifice of a water collection tank, wherein the inlet orifice is located below a water level of the water collection tank; and (4) maintaining the water level of the water collection tank such that a second pressure of water at the inlet orifice is greater than the first pressure of the process stream.
Some embodiments may include additional steps, either alone or in combination. For example, an additional step may include circulating air through the water collection tank, or circulating a cathode exhaust stream from a fuel cell through an atmosphere of the water collection tank to an oxidizer. Embodiments of methods under the invention may also refer to any of the systems and combinations of features described herein.
In another aspect, the invention provides a method of water management for a fuel cell system, including at least the following steps: (1) flowing a fuel cell process stream containing liquid water through a gas conduit at a first pressure; (2) draining the liquid water from the gas conduit into a drain conduit; (3) draining the liquid water through the drain conduit into an inlet orifice of a water collection tank, wherein the inlet orifice is located above a water level of the water collection tank; and (4) maintaining the water level of the water collection tank such that a second pressure of water at the inlet orifice is greater than the first pressure of the process stream.
Advantages and other features of the invention will become apparent from the following description, drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of an apparatus for collecting condensate in an integrated fuel cell system.
FIG. 2 is a schematic representation of an apparatus for collecting condensate in an integrated fuel cell system.
FIG. 3 is a schematic representation of an apparatus for collecting condensate in an integrated fuel cell system.
FIG. 4 is a flow chart of a method for collecting condensate in an integrated fuel cell system.
DETAILED DESCRIPTION
In general, in one embodiment, the invention provides a water management subsystem for a fuel cell system. A gas conduit is operated at a first pressure, and is associated with a water collection tank containing a level of water. A drain line is connected to the gas conduit to allow condensate to drain from the gas conduit. The drain line is connected to the water tank at an inlet orifice of the tank. The inlet orifice is located below the water level of the tank. The connection of the drain line to the gas conduit is located either above the tank, or above the water level in the tank. The height of water in the tank provides a pressure at the bottom of the tank. The water level is set such that the pressure at the inlet orifice is greater than the pressure of the gas conduit. It will be appreciated that this pressure relationship allows water to drain into the water tank as the level of water in the drain line rises to a level above the water level in the tank. This arrangement thereby allows draining of condensate from the gas conduit while preventing gas from the gas conduit from blowing into the tank. This arrangement also eliminates the need for float valves (see below) or other devices for separating condensate from a gas stream.
In another embodiment of the invention, the water tank is maintained partially full, and the atmosphere in the tank above the water level is maintained at a pressure such that the pressure at the inlet orifice under the water level is greater than the pressure of the gas conduit. In some embodiments, the pressure of the atmosphere is maintained by circulating a process stream through the water tank. For example, the cathode feed or exhaust streams may be circulated through the tank.
In another embodiment, the water tank includes a second inlet orifice connected to a water supply. The water supply can be a pump, reservoir, pressurized line or other arrangement adapted to supply water to the tank when desired. The water tank further includes a level sensor connected to the water supply (e.g., via a pump or valve) such that control of the water level in the tank is automated. The level sensor can also be connected to a system controller (e.g., programmable circuitry) that in turn controls the water supply according to a signal from the level sensor.
In another embodiment, a method of fuel cell system water management is provided. The steps include: (1) flowing a fuel cell process stream containing liquid water through a gas conduit at a first pressure; (2) draining a portion of the liquid water from the gas conduit into a drain conduit; (3) draining the liquid water through the drain conduit into an inlet orifice of a water collection tank, wherein the inlet orifice is located below a water level of the water collection tank; and (4) maintaining the water level of the water collection tank such that a second pressure of water at the inlet orifice is greater than the first pressure of the process stream.
In another embodiment, the method can further include flowing a cathode exhaust stream through an atmosphere of the water tank. The method can also include maintaining a pressure of the atmosphere such that the pressure at the inlet orifice under the water level is greater than the pressure of the gas conduit.
Referring to FIG. 1, a fuel cell stack 100 is shown associated with a water tank 102 . The stack 102 includes a inlet gas conduit 104 for feeding cathode gas to the stack 100 , and an outlet gas conduit 106 for exhausting the cathode gas from the stack 100 . The inlet conduit 104 is connected to the water tank 102 via drain line 108 . The outlet gas conduit 106 is also connected to the water tank 102 . Orifice 112 limits the amount of cathode gas that is bled from the inlet conduit 104 to the water tank 102 . The water tank 102 includes a vent 114 through which the gas exits as it circulates through the tank 102 . The vent 114 can exhaust to the ambient atmosphere, or can be fed to another part of the system, such as an anode exhaust gas combustor 126 (also referred to as “anode tailgas oxidizer” or ATO). Some embodiments may not include a vent. The water tank 102 includes a level sensor 116 adapted to measure the water level in the tank. The tank further includes a make-up water line 120 that is driven by a pump 122 , and a drain 130 . The sensor 116 is connected to a controller 118 (e.g., a programmable circuit) that is connected to the pump 122 . The controller 118 automatically maintains a desired level of water in the tank 102 . In the embodiment shown in FIG. 1, a condensate drain line 124 connects the ATO 126 to the water tank 102 .
The drain line 124 feeds into the water tank 102 at an inlet orifice 128 . The inlet orifice 128 is located under the level of water in the tank 102 . The atmosphere in the tank has a pressure P 3 and the inlet orifice 128 has a pressure P 2 . The pressure P 2 is greater than a pressure P 1 of the ATO drain line. In some embodiments, a drain line such as line 124 can originate from a position above the water tank 102 , and extend down to a position below the water tank 102 before running back up to its inlet orifice 128 . In such arrangements, it may be more difficult for gas to blow through the line, either from the drain line or from the water tank should the level run low, since a “j-trap” arrangement is provided with a larger column of water than an arrangement relying on the tank water level alone.
In another embodiment based on the system described in FIG. 1, the inlet orifice 128 is located above the water level in the tank. The j-trap feature 132 (generally an optional feature, also referred to in some cases as a “water trap bend”) ensures that an amount of condensate remains in the drain line 124 so that gas does not blow through the line 124 into the tank 102 . Again, drain line 124 may represent a drain line from any process stream, not just one from ATO 126 . As discussed above, the height of the j-trap feature 132 may be selected based on the pressures P 1 or P 3 , or as otherwise desired. Placing the inlet orifice 128 above the water level provides an advantage in systems where a hot ATO 126 may be fluidly isolated when it is shut down and will tend to pull a vacuum as it cools. In some systems, such a vacuum might cause water from tank 102 to backup through drain line 124 , potentially flooding the system or causing other problems. Similarly, in systems where condensate is drained from anode or cathode inlets or outlets to the stack (whether passed through a float valve or not see below), it may be desirable to provide a drain line on such streams with a j-trap feature that empties into the tank at a point above the water level. This is because fuel cell stacks are typically fluidly isolated when they are shut down, and may produce vacuums as they cool. The j-trap features previously described can be integral to the water tank or a stack manifold including a water tank, or may consist of a simple j-trap bend in the drain line plumbing.
Referring to FIG. 2, the system of FIG. 1 is modified in that the conduit 208 off the cathode feed conduit 204 is connected to the water tank 202 at an inlet orifice 240 below the water level in the tank 202 . Thus, in this embodiment, the cathode feed conduit 204 is not used to circulate air through the water tank 202 . Rather, conduit 208 serves as a condensate drain line. The pressure at the inlet orifice 240 is greater than the pressure of the cathode feed conduit 204 , due to the water level in the tank 202 and the pressure of the atmosphere in the tank 202 .
Referring to FIG. 3, the system of FIG. 1 further includes anode gas feed conduit 342 and exhaust conduit 344 . Drain line 346 allows condensate to drain from conduit 342 into water trap 348 . Water trap 348 is essentially a gravity-biased float valve wherein water entering the trap causes a float valve to open as it floats away from a drain orifice. When there is no water in the trap 348 , the float valve is closed such that gas is prevented from flowing through the trap 348 . Such devices are well known in the art. The water trap 348 is connected to drain line 350 that feeds condensate to the tank 302 . Similarly, anode exhaust conduit 344 is connected to drain line 352 which leads to water trap 354 . Drain line 356 allows condensate to flow from water trap 354 to the tank 302 .
In some embodiments, it may be preferable that gas conduits that contain combustible gasses such as the anode feed 342 and the anode exhaust 344 are not drained directly into the water tank 302 . Water traps such as 348 and 354 are used to limit the exposure of the water tank to such streams. One concern is that combustible gasses can dissolve into water and accumulate in gas pockets as the water temperatures fluctuates. Such gas pockets can pose safety problems such as the threat of explosions, etc. This is one reason that the atmosphere of the tank may be continually purged in some embodiments with an air stream. It may be preferable, therefore, to provide water traps on drain lines running off process streams that contain combustible gasses, while drain lines from non-combustible process streams are not provided with water traps. In other embodiments, as an example, the atmospheric purge of the water tank may be sufficient to prevent any buildup of combustible gasses in the tank such that devices such as water traps 348 and 354 can be eliminated. In other words, in some cases the term “gas conduit” may refer to a non-combustible process stream, while in other embodiments the term may refer to any gaseous process stream in the fuel cell system.
Referring to FIG. 4, a method of fuel cell system water management is provided. The steps include: ( 400 ) flowing a fuel cell process stream containing liquid water through a gas conduit at a first pressure; ( 402 ) draining a portion of the liquid water from the gas conduit into a drain conduit; ( 404 ) draining the liquid water through the drain conduit into an inlet orifice of a water collection tank, wherein the inlet orifice is located below a water level of the water collection tank; and ( 406 ) maintaining the water level of the water collection tank such that a second pressure of water at the inlet orifice is greater than the first pressure of the process stream.
Further embodiments of the invention may include apparatus and methods based on any combination of the features and aspects described above.
While the invention has been disclosed with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations therefrom. It is intended that the invention covers all such modifications and variations as fall within the true spirit and scope of the invention. | The invention generally relates to a method and apparatus for collecting condensate from process streams in an integrated fuel cell system. In one aspect, the invention provides a water management subsystem for a fuel cell system. A gas conduit contains a gas at a first pressure. A water tank in the system contains water at a certain level. The water tank has an inlet orifice below the water level. A drain conduit has a first end and a second end. The drain conduit is connected at the first end to the gas conduit, and the drain conduit is connected at the second end to the inlet orifice of the water tank. The water level and the inlet orifice have a vertical height of water between them corresponding to a head pressure greater than the first pressure. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates to an improved method for selectively preparing 3-oxo-4-aza-5α-androstane compound under mild conditions.
DESCRIPTION OF THE PRIOR ART
[0002] Finasteride (17β-(N-tert-butylcarbamoyl)-5α-4-aza-androst-1-en-3-on), the compound of formula (II) having an androstane backbone, is effective in treating benign prostatic hypertrophy and androgenetic alopecia:
[0003] Benign prostatic hypertrophy and androgenetic alopecia are caused by binding of 5α-dihydrotestosterone (DHT) derived from testosterone to androgen receptor. The conversion of testosterone into 5α-dihydrotestosterone is mediated by testosterone 5α-reductase which is inhibited by finasteride. Such inhibition of 5α-dihydrotestosterone by finasteride results in rapid recovery of prostate and increased hair growth. Finasteride thus is effective to benign prostatic hypertrophy and good agent for treating androgenic alopecia which exhibits only low, temporary side effects, and it is the only orally administrable among the two hair-growth agents approved by FDA of the United Sates.
[0004] Finasteride can be conventionally prepared by converting the carboxylic group of the 17β-position of 3-oxo-4-aza-5α-androstane-17β-carboxylic acid of formula (I) into a t-butylcarbamoyl group and then carrying out dehydrogenation at the 1,2-positions, or carrying out dehydrogenation at the 1,2-positions and then converting the 17β-position carboxylic group into a t-butylcarbamoyl group:
[0005] For example, a process for preparing 3-oxo-4-aza-5α-androstane-17β-carboxylic acid of formula (I) is disclosed in U.S. Pat. No. 4,760,071 and the J. Med. Chem. 29, 2298 (1986), wherein the 3-oxo-4-aza-5-androstene compound of formula (III) is reduced with the hydrogen in the presence of a PtO 2 catalyst under a hydrogen atmosphere of 40 psi to produce the compound of formula (I).
[0006] The above reduction process selectively produces the compound of formula (I) having the 5-hydrogen oriented at 5α-position, without giving the isomer thereof, the compound of formula (IV) having the 5-hydrogen at the 5β-position. However, this asymmetric reduction process requires the use of explosive hydrogen and an expensive catalyst under high pressure condition.
[0007] Also disclosed in J. of Pharmaceutical Sciences. 63, p 19 (1974) is a method of reducing a steroid compound having a structure similar to the compound of formula (III) to produce a 5α-compound using formic acid and N-methylformamide. However, this process is conducted under high temperature and high pressure conditions and gives a poor productivity.
SUMMARY OF THE INVENTION
[0008] Accordingly, it is a primary object of the present invention to provide an improved method for selectively preparing the compound of formula (I) under mild conditions.
[0009] In accordance with the present invention, there is provided a method for preparing the compound of formula (I) comprising heating the compound of formula (III) in a mixture of formic acid and an alkanediol in the presence of zinc:
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The above and other objects and features of the present invention will become apparent from the following description of the invention taken in conjunction with the following accompanying drawings, which respectively show:
[0011] FIG. 1 : a high performance liquid chromatography (HPLC) scan of the compound of formula (I) prepared in accordance with the inventive method; and
[0012] FIG. 2 : an HPLC scan of the compound of formula (I) prepared in Comparative Example 1 in the absence of zinc; and
[0013] FIG. 3 : an HPLC scan of the compound of formula (I) prepared in Comparative Example 2 using formic acid and methylformamide.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The compound of formula (III) used as a starting material of the present invention can be prepared by a conventional method (U.S. Pat. No. 4,760,071 and the J. Med. Chem. 29, 2298 (1986)).
[0015] In accordance with the present invention, the compound of formula (I) can be prepared by dissolving the compound of formula (III) in a mixture of formic acid and an alkanediol, adding activated zinc thereto, and heating the resulting mixture.
[0016] In the inventive method, formic acid may be used in an amount of 3 to 30 ml, preferably 5 to 15 ml based on 1.0 g of the compound of formula (III); and the alkanediol, in an amount of 2 to 20 ml, preferably 5 to 10 ml, based on 1.0 g of the compound of formula (III).
[0017] The alkanediol which may be used in the present invention includes ethylene glycol, propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol and 2,3-butandiol, and the like, among which ethylene glycol is preferred.
[0018] The zinc used in the present invention enhances both the selectivity of the target 5α-compound and the yield, and also reduces the reaction time.
[0019] Zinc may used in 4 to 10 equivalents, preferably, 6 to 8 equivalents, based on a mole of the compound of formula (III), and in the total absence of the isomeric 5β-by product, the target 5α-compound is produced in a high yield of 80%. When zinc is not used, the target 5α-compound is produced in a yield of only about 50% together with 10 to 20% of the isomeric 5β-compound.
[0020] The reduction in accordance with the present invention may be carried out at a temperature of 80 to 130° C., preferably 100 to 110° C., for 4 to 8 hours.
[0021] Thus, in accordance with the simple method of the present invention, the target compound of formula (I) can be selectively produced in a high yield under mild conditions.
[0022] The present invention will be described in further detail with reference to Examples. However, it should be understood that the present is not restricted by the specific Examples.
EXAMPLE
Preparation 1: Preparation of 17β-carboxy-5-oxo-A-nor-3,5-secoandrostan-3-onic acid
[0023] 16 g (50 mmol) of 3-oxo-4-androstene-17β-carboxylic acid was dissolved in 240 ml of t-butanol, 16 g (150 mmol) of sodium carbonate dissolved in 40 ml of water was added thereto, and then heated to 80° C. Added dropwise thereto is was a solution, which is preheated to 60° C., of 53.5 g (250 mmol) of sodium metaperiodate and 4.0 g (25 mmol) of potassium permanganate dissolved in 300 ml of water. The resulting mixture was refluxed for 3 hours and left at room temperature overnight. The inorganic materials were filtered-off through celite, the filtrate was successively washed with water and 250 ml of 10% sodium hydrogen sulfite, t-butanol was removed under a reduced pressure, and the residue was acidified with concentrated HCl. The acidified residue was then extracted with 320 ml of methylene chloride, washed successively with 320 ml of 5% sodium hydrogen sulfite and 320 ml of brine, and distilled under a reduced pressure, to obtain 14.5 g of the title compound (yield: 86%) as a pale yellow solid.
[0024] H-NMR(δ, CDCl 3 ): 0.82(3H, 19-CH 3 ), 1.16(3H, 18-CH 3 ),1.20˜2.30 (15H, cyclic-CH), 1.53(2H, 1-CH 2 ), 2.40(2H, 2-CH 2 ), 2.50(1H, 17-CH), 11.85(1H, COOH)
Preparation 2: Preparation of 3-oxo-4-aza-5-androstene-17β-carboxylic acid (the Compound of Formula (III))
[0025] 10 g of 17β-carboxy-5-oxo-A-nor-3,5-secoandrostan-3-onic acid (30 mmol) obtained in Preparation 1 was dissolved in 30 ml of ethylene glycol, and 75 ml of 2.0M ethanolic ammonia solution (150 mmol) was added thereto, stirred for an hour at 40 to 50° C., and refluxed for 12 hours. The resulting mixture was cooled to room temperature and ethanol was distilled off under a reduced pressure. To the residue was added 150 ml of water and the resulting mixture was acidified with 10% HCl to pH 1.5. Precipiates formed were filtered, washed with water, and dried at 45° C., to obtain 6.6 g of the title compound (yield: 70%) as a white solid.
[0026] H-NMR(δ, DMSO-d 6 ): 0.57(3H, 19-CH 3 ), 0.91(3H, 18-CH 3 ), 0.95˜2.30 (18H, cyclic-CH), 4.76(1H, 6-CH), 9.17(1H, NH), 11.85(1H, COOH)
Example 1
3-oxo-4-aza-5α-androstane-17β-carboxylic acid (the Compound of Formula (I)-1)
[0027] 3.2 g (10 mmol) of 3-oxo-4-aza-5-androstene-17β-carboxylic acid obtained in Preparation 2 was dissolved in a mixture of 45 ml of formic acid and 15 ml of ethylene glycol, and 2.6 g (80 mmol) of activated zinc was added thereto. The mixture was reacted for 8 hours at 100 to 105° C. and cooled to room temperature. The suspended solid was removed by filteration, and the solvent in the filtrate was removed under a reduced pressure. 13 ml of N-methylformamide was added to the residue, and the resulting mixture was stirred for 30 minutes in an ice bath. Precipitates formed were then filtered and dried at 45° C., to obtain 2.6 g of the title compound (yield: 81%) as a white solid.
[0028] The product thus obtained was analyzed by HPLC and the result is shown in FIG. 1 . As can be seen in FIG. 1 , only the target 5α-compound (retention time: 11.996) is detected, the isomeric 5β-compound being not detectable.
[0029] H-NMR(δ, DMSO-d 6 ): 0.56(3H, 19-CH 3 ), 0.72(3H, 18-CH 3 ), 0.80˜1.30 (8H, cyclic-CH), 1.40˜1.70(7H, cyclic-CH), 1.87(2H, 16-CH), 2.10(2H, 2-CH 2 ), 2.30(1H, 17-CH), 3.0(1H, 5-CH), 7.15(1H, NH), 11.85(1H, COOH)
Example 2
3-oxo-4-aza-5α-androstane-17β-carboxylic acid (the Compound of Formula (I)-2)
[0030] 3.2 g (10 mmol) of 3-oxo-4-aza-5-androstene-17β-carboxylic acid obtained in Preparation 2 was dissolved in a mixture of 16 ml of formic acid and 32 ml of ethylene glycol, and 2.6 g (80 mmol) of activated zinc was added thereto. The mixture was reacted for 8 hours at 110 to 120° C., and cooled to room temperature. The suspended solid was removed by filtration, formic acid was removed under a reduced pressure. The residue was dissolved in 300 ml of chloroform and washed successively with 150 ml portions of 5% aqueous sodium carbonate solution (×2) and 150 ml portions of water (×3). The chloroform layer was separated, then dried, filtered and the solvent was removed under a reduced pressure. 13 ml of N-methylformamide was added to the residue and stirred for 30 minutes in an ice bath. Precipitates formed were then filtered and dried at 45° C., to obtain 2.7 g of the title compound (yield: 83%) as a white solid.
[0031] The product thus obtained was analyzed by HPLC and the result showed that only the 5α-compound (retention time: 11.996) was produced. H-NMR data was the same as in Example 1.
Comparative Example 1
Preparation of 3-oxo-4-aza-5α-androstane-17β-carboxylic acid (the Compound of Formula (I)) in the Absence of zinc
[0032] 3.2 g (10 mmol) of 3-oxo-4-aza-5-androstene-17β-carboxylic acid obtained in Preparation 2 was dissolved in a mixture of 45 ml of formic acid and 15 ml of ethylene glycol, and reacted for 8 hours at 100 to 105° C. The reaction mixture was cooled to room temperature, the residual solid was remove by filtration and the solvent was distilled off under a reduced pressure. 13 ml of N-methylformamide was added to the resulting residue and stirred for 30 minutes in an ice bath. Precipitates formed were then filtered and dried at 45° C., to obtain 1.7 g of the title compound (yield: 53%) as a white solid.
[0033] The product thus obtained was analyzed by HPLC and the result is shown in FIG. 2 , wherein the area of 5β-compound peak (retention time: 12.956) is 15% relative to the area of the 5α-compound peak (retention time: 12.187) of 85%. That is, a large amount of the undesired 5β-compound is produced.
Comparative Example 2
Preparation of 3-oxo-4-aza-5α-androstane-17β-carboxylic acid (the Compound of Formula (I)) Using a Mixture of formic acid and N-methylformamide
[0034] 3.2 g (10 mmol) of 3-oxo-4aza-5-androstene-17β-carboxylic acid obtained in Preparation 2 was dissolved in a mixture of 45 ml of formic acid and 15 ml of N-methylformamide, and reacted for 8 hours at 100 to 105° C. The reaction mixture was cooled to room temperature, the residual solid was filtered off, formic acid was removed under a reduced pressure, and the remaining solution was stirred for 30 minutes in an ice bath. Precipitates formed were then filtered and dried at 45° C., to obtain 1.9 g of the target compound (yield: 59%) as a white solid.
[0035] The product thus obtained was analyzed by HPLC and the result is shown in FIG. 3 , wherein the area of the 5β-compound peak (retention time: 12.770) is 35% relative to the 5α-compound peak (retention time: 12.046) of 65%. That is, a large amount of the undesired 5β-compound is produced.
[0036] While the invention has been described with respect to the specific embodiments, it should be recognized that various modifications and changes may be made by those skilled in the art to the invention which also fall within the scope of the invention as defined as the appended claims. | This invention relates to a method for selectively preparing the 3-oxo-4-aza-5¥á-androstane compound which is used as an intermediate of finasteride by heating 3-oxo-4-aza-5-androstene in a mixture of formic acid and an alkanediol in the presence of zinc. | 2 |
BACKGROUND OF THE INVENTION
[0001] The invention refers to a method for producing a stacking column for storing storage items one above the other or next to each other on pawls which are rotatably arranged around a pivot between two side cheeks, and also to a kit for producing a corresponding stacking column and pawls for use in such stacking columns.
[0002] Stacking columns are known in multifarious forms and on the market. Stacking columns are used primarily during the production of body parts in the automobile industry. The corresponding body parts are taken from the presses via robots and before further processing are intermediately stored in stacking columns. As a rule, four stacking columns are set up in a rectangle. Each stacking column has a multiplicity of pawls which are arranged one above the other. A first pawl in this case is mostly located in the stand-by position. If a storage item is laid upon this pawl, the pawl pivots into the working position and in the process drives a subsequent pawl which in this way gets into the stand-by position. Such a stacking column is known for example from DE 38 11 310 C1.
[0003] Stacking columns are also used, however, for the horizontal storage of storage items, as is described for example in DE 40 20 864 A1. The principle of operation of these horizontal stacking columns is similar to that of the vertical stacking columns.
[0004] The spacing of the pawls constitutes a significant problem in stacking columns. Different storage items also require a different spacing. For this, in WO 03/03551 A1 for example, ovision is made for the pawls to be interconnected at least via a link plate, wherein for reduction of a spacing of adjacent pawls at least one link plate is formed in an angled or cranked or arc-shaped configuration.
[0005] It is the object of the present invention to develop a method for producing a stacking column by means of which stacking columns of different desired spacings can be produced considerably easier.
SUMMARY OF THE INVENTION
[0006] The effect of side cheeks, pawls and bearing blocks forming a kit for producing stacking columns with different spacing leads to the achieving of the object.
[0007] This means that there is no longer a rigid production of stacking columns, but that stacking columns can be adapted by the manufacturer and/or customer to the requirements of the customer, especially as far as the spacing is concerned. In this case, provision is made for the side cheeks to always remain the same, whereas the pawls and bearing blocks can vary. Also, in the case of the bearing blocks it can be desirable that these remain the same, but that their distance from one another is altered by means of spacers. As a result of this, a different spacing again ensues.
[0008] So that the bearing blocks or spacers can be associated with the side cheeks, these side cheeks must have guides. For the sake of simplicity, the guide is formed by means of two angle-pieces which between them form an undercut slot or a channel. The bearing blocks and, if applicable, spacers, can then be simply inserted into this channel or into the slot. They can also be removed just as simply from the slot and be substituted by other bearing blocks and/or spacers. As a result of this, an accurate adaptation to the desired spacing is carried out.
[0009] The bearing blocks serve for the retention of the pawls. Therefore, they have holes for accommodating corresponding pivot ends of the pawl pivots, wherein the bearing blocks are pushed onto these pivot ends and then inserted into the slots of the side cheeks.
[0010] Furthermore, provision is made for a rotational movement of the pawl between the side cheeks to be limited. For this, stops can project either from the side cheeks or from a back wall, as are described for example in DE 298 09 118 U1.
[0011] A kit consisting of side cheeks, pawls and bearing blocks and, if applicable, spacers for producing stacking columns with different spacing for storing storage items one above the other or next to each other on pawls which are rotatably arranged around a pivot between two side cheeks, is claimed by the invention. This kit for example can be made available to a customer for producing stacking columns, wherein different pawls, bearing blocks of different length and corresponding spacers are also supplied to the customer at the same time. Only the side cheeks with the guides remain the same.
[0012] Furthermore, protection is desired for a stacking column for storing storage items one beneath the other or next to each other on pawls which are rotatably arranged around a pivot between two side cheeks, wherein the pivots of the pawls are accommodated in bearing blocks which are removably or exchangeably associated with the side cheeks. In order to bring the respective pawl in such a stacking column from a neutral position into a stand-by position and from a stand-by position into a working position, the pawls can be interconnected via corresponding link plates or other jointed connections.
[0013] In order to also simplify this function here, however, a special pawl has been developed for which protection is independently desired. Such a pawl, as is generally customary, comprises a carrier arm and a control arm. According to the invention, an insert, which is exchangeable in design, is now provided in the control arm. In this way, a height of this insert can be adapted to a desired spacing. For this, a wedge-shaped projection preferably projects from the insert, the height of which projection varies depending upon the insert which is used.
[0014] Furthermore, a very wide variety of different attachments or extensions can be located on the carrier arm or attached to the carrier arm which can take into consideration the respective desires of the user. It is also conceivable as a result of this for the pawl itself to be extended, or for it to be able to be coated for example with a wear-resistant coating. Furthermore, it is conceivable for an extension to project downwards from the pawl, which extension presses onto a storage item on a carrier arm of a pawl lying beneath it and clamps this storage item.
[0015] In the case of this pawl according to the invention, it is particularly also conceivable for the actual basic body, which can always be used again, to be produced in one piece together with the pivot ends. For this, production in a casting process or injection molding process from plastic lends itself.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Further advantages, features and details of the invention result from the subsequent description of preferred exemplary embodiments and also with reference to the drawing; in this drawing
[0017] FIG. 1 shows a side view of a part of an open stacking column;
[0018] FIG. 2 shows a plan view of parts of a stacking column according to the invention;
[0019] FIG. 3 shows a perspective plan view of a pawl according to the invention;
[0020] FIG. 4 shows a perspective bottom view of the pawl according to FIG. 3 ;
[0021] FIG. 5 shows a plan view of the pawl according to the invention according to FIG. 3 ;
[0022] FIG. 6 shows a longitudinal section through the pawl according to FIG. 5 along line A-A;
[0023] FIG. 7 shows a longitudinal section through the pawl according to FIG. 5 along line B-B.
DETAILED DESCRIPTION
[0024] A stacking column P according to the invention, according to FIGS. 1 and 2 , has two side cheeks 1 and 2 which are interconnected by means of a back wall 3 . A multiplicity of stops 4 are disengaged from the back wall 3 , as is described in more detail in DE 298 09 118 U1.
[0025] According to the invention, a guide 6 for bearing blocks 7 is provided in each case on each inner wall 5 of the two side cheeks 1 and 2 . Each guide 6 in this case comprises two angle-pieces 8 . 1 and 8 . 2 which are arranged in a mirror-image manner and so form an undercut slot 9 for the guiding of the bearing blocks 7 .
[0026] A hole 10 which serves for accommodating pivot ends 11 . 1 or 11 . 2 of a pivot 12 and of a pawl 13 is formed in each bearing block 7 . A corresponding pawl 13 is shown in FIGS. 3 to 7 .
[0027] The pawl 13 has a basic body 14 which forms a carrier arm 15 one side of the pivot 12 and forms a control arm 16 on the other side of the pivot 12 . In this case, the basic body 14 and the pivot 12 or the pivot ends 11 . 1 and 11 . 2 are preferably produced in one piece from plastic in a casting process or injection molding process.
[0028] A recess 17 , in which an insert 18 is exchangeably seated, is formed in the control arm 16 and reaches over the pivot 12 . A wedge-shaped projection 19 projects from this insert 18 . The insert 18 itself is connected by means of a screw 20 to the basic body 14 , wherein it still engages by a front strip 21 in a slot 22 which is formed in the basic body 14 .
[0029] More holes 23 and 24 are furthermore to be seen on the control arm 16 and can serve for example for accommodating weights by which a pawl 13 can be returned to its neutral position between the two side cheeks 1 and 2 .
[0030] A recess 26 , which extends from a lower surface 25 of the pawl 13 , is formed in the carrier arm 15 . This serves for example for accommodating an also exchangeable attachment 27 on the carrier arm 15 providing the pawl 13 which lies beneath it is in the neutral position. This attachment 27 is connected by two screws 28 . 1 and 28 . 2 to the carrier arm 15 .
[0031] The principle of operation of the present invention is as follows:
[0032] An operable stacking column of a desired spacing is produced by corresponding bearing blocks 7 being pushed onto the pivot ends 11 . 1 and 11 . 2 of the pawls 13 and together with these pawls 13 being inserted into the guides 6 . A length l of the bearing blocks 7 in this case is selected so that a desired spacing is achieved.
[0033] If a stacking column P is to be produced with a different spacing, then the existing bearing blocks 7 with the corresponding pawls can be pushed out of the guides 6 and substituted by bearing blocks of a different length. It is also conceivable, however, for the bearing blocks 7 to always have a similar length but for spacers to be inserted between two bearing blocks so that by means of these spacers a corresponding spacing of the holes 10 and consequently of the pivots 12 of the pawls 13 is achieved.
[0034] It is conceivable, and also lies within the scope of the invention, for a series of stacking columns to be provided with corresponding bearing blocks for a desired spacing, but for another series of stacking columns to be provided with bearing blocks for a different spacing. It is also conceivable for the entire arrangement to be offered to a customer with various bearing blocks or spacers so that the customer himself can assemble a stacking column. The pawls in this case can be the same or different; pawls which differ in length can especially be offered.
[0035] The projection 19 of the insert 18 principally serves for bringing a subsequent pawl from a neutral position into a stand-by position and from the stand-by position into a working position, as is especially described in DE 38 11 310 C2. Therefore, the height h of the projection 19 must also be matched to a desired spacing.
[0036] The attachment 27 is also exchangeable and can be adapted to desired requirements. By means of corresponding attachments or extensions the carrier arm 15 of the pawl 13 can either be extended or made more resistant to wear. Furthermore, it is also conceivable to affix an extension on the lower surface 25 of the carrier arm 15 , which extension projects downwards and presses a storage item, which lies on the lower pawl, onto the carrier arm of this pawl. | A method for producing a stacking column (P) for storing storage items above or alongside one another on pawls ( 13 ) which are arranged between two side walls ( 1, 2 ) such that they can rotate about an axis ( 12 ), the side walls ( 1, 2 ), pawls ( 13 ) and mounting brackets ( 7 ) form an assembly for producing stacking columns (P) of varying pitch. | 1 |
RELATED APPLICATION DATA
[0001] This application is a continuation of application Ser. No. 09/422,831, filed Oct. 21, 1999, now pending.
BACKGROUND OF THE INVENTION
[0002] (1) Field of the Invention
[0003] This invention relates generally to dynamoelectric devices, such as electric motors, and more particularly to the stator construction of the device where the stator assembly consists of a stator having a center bore with a plurality of stator poles circumferentially spaced around the center bore. The stator poles have wiring wrapped in windings around the stator poles and the windings have end turns arranged around the stator center bore at axially opposite sides of the stator. The end turns of the windings are laced and manually positioned at opposite ends of the stator to prevent their interference with the rotor assembly in the stator center bore, the motor housing, and/or with the end plates of the motor housing.
[0004] (2) Description of the Related Art
[0005] In a traditional dynamoelectric device such as a motor, the stator consists of a plurality of stator poles surrounding a rotor. Devices like this are well known in the art, and one is shown generally in FIG. 1. Because such devices are well known, their assembly is only generally discussed here. The stator can be a collection of individual poles as in a segmented stator, or can be formed together as a single unit. As shown in FIG. 1, the stator poles 10 , generally, have a “I”-shaped cross-section, which creates two channels on opposite sides of a central member 12 or web of the “I”-shaped cross section. A length of wire is wrapped around the central member of the “I”-shaped cross-section forming wire windings 14 that are partially contained within the channels on opposite sides of the central member 12 . Where the wire winding exits one channel at an end of the stator pole 10 , crosses over the central member 12 , and is redirected to enter the channel on the opposite side of the central member 12 , the wire winding creates an end turn 16 .
[0006] End turns 16 of the wire windings 14 are created at both axial ends of each stator pole. At times windings are formed with the end turns 16 positioned at an axial distance from the opposite ends of the stator pole 10 to provide a smooth transition as they wrap around the end of the stator pole from one channel to the other channel. At this distance from the stator pole, the end turns are grouped and bound together with laces 18 . Grouping wire windings 14 with laces 18 prevents the wire windings from interfering with subsequent assembly operations. Generally, materials such as insulated tape or common nylon electrical tie wraps are used as laces 18 . After winding, the stator assembly is assembled into a housing 20 , a rotor assembly (not shown) is inserted into the stator center bore, and end plates or end bells (not shown) are assembled over the opposite ends of the housing with the rotor shaft supported by bearings in each of the end plates.
[0007] There are many methods of motor construction, and the method described herein and shown in FIG. 1, demonstrates one technique where the inside of the housing 20 is fitted to the outer wall of the stator assembly 22 . By lacing the end turns 16 , the wire windings 14 are prevented from accidentally fouling areas adjacent to the stator poles where the housing 20 , rotor assembly (not shown), or end plates (not shown) are installed. As the stator is wound, winding leads 24 are brought from the wire windings 14 around the stator pole for connection outside the stator assembly 22 . The winding leads provide current input to the stator poles 10 for the development of electromotive force, and the winding leads 24 provide connection for other electrical switching devices used to regulate current and stator controls. Winding leads 24 must be sized in length for the particular connection to be made outside the stator assembly 22 , and the winding leads are often color coded to provide assembly personnel a reference during connection to external devices.
[0008] This method of stator construction has many shortcomings. Lacing the end turns 16 and grouping the winding leads 24 is a manually intensive operation, requiring significant manipulation of the wire windings. The manipulation of wire windings 14 causes quality problems. Moreover, the process of generating winding leads 24 and installing winding lead connectors adds assembly time to motor manufacturing.
[0009] Misplaced end turns 16 and wire windings 14 can compromise conductivity in the stator assembly 22 . As the end turns 16 are manually positioned to clear areas adjacent to the stator poles 10 for the housing 20 , the rotor assembly, or end plate installation, grounding of the wire windings can occur. Generally, the wound stator poles 10 are press fit into the housing 20 . During this operation, loose winding wires can be accidentally crimped or damaged against the housing 20 . End plates (not shown) are often mechanically fastened to the housing 20 . Similarly, during this phase of motor construction, loose winding wires can be accidentally crimped or damaged when the end plates are bolted to the housing. When the rotor assembly (not shown) is installed into the stator assembly bore it is critical that the wire windings 14 and end turns 16 do not foul the interface or air gap between the rotor assembly and the stator assembly bore. Often rotor assembly installation is a blind installation, where the end plates obscure viewing of the rotor assembly. It is important that the wire windings and end turns clear the rotor and shaft of the rotor assembly and the bearing assemblies to be fitted thereon.
[0010] Protective sealant is applied to the stator assembly 22 and housing to prevent humidity from damaging the wire windings 14 when the motor is de-energized after a period of operation. The protective sealant also provides electrical insulation for the wire windings 14 from other components and debris. This sealant can become cracked if manual manipulation of the end turns 16 and wire windings 14 is needed when the stator assembly 22 is assembled with the housing, the end shields, and the rotor assembly.
[0011] Generation of the winding leads 24 is another manual operation required when winding the stator poles. Winding leads 24 must be properly sized in length after winding to allow proper connection to switching devices outside the stator assembly. The winding leads 24 must be specially marked for terminal points, which vary depending upon customer requirements and motor configuration. The length of the winding leads 24 must be sufficient to allow connection to the terminal points, and the ends of the winding leads 24 must be fitted with connectors. These connectors must be specifically configured for the specific terminal point and connector style required for the customer application. Often, winding leads 24 and connectors are color coded to assist assembly personnel in making proper connections. In the prior art mechanical connectors and shrink caps on winding leads 24 have been used to provide connections to terminal points. However, the preparation of winding leads 24 in this manner creates non-standard interfaces for motor construction. This creates inflexibility in the manufacturing lines and slows overall motor production rates.
[0012] The winding leads 24 and the connectors attached thereon are frequently used during inspection and testing. Manual connection and disconnection at these points during this phase of the manufacturing process is also labor-intensive. Quality can be compromised as protective sealant is sometimes damaged from the areas of the leads where connection and re-connection was made.
[0013] The problems set forth above could be overcome by a device that attaches to the stator assembly 22 of the motor and contains the winding leads 24 and end turns 16 therein, thus eliminating manual lacing of the winding end turns. The device would also have a terminal container to provide uniform connector styles for winding leads. Additionally, the device would be provided with a compartment for housing protectors such as temperature and current overload circuitry.
SUMMARY OF THE INVENTION
[0014] The shortcomings of the prior art of FIG. 1 are overcome by the present invention which provides a device that contains the end turns of a stator and provides a convenient mechanism for the connection of winding leads of the stator. In general, the invention will be used on the stator assembly such as that shown in FIG. 1, comprising a plurality stator poles, which are wound with wire and arranged in a cylindrical orientation to create an outer diameter adapted for accepting a housing and an inner diameter shaped to accept a rotor assembly (not shown). The wire windings will have end turns positioned at the opposite axial ends of the stator poles. Comprised with the wire windings are the winding leads.
[0015] [0015]FIG. 4 shows the apparatus of the invention installed on one end of a stator such as that shown in FIG. 1 and described earlier. It should be understood that this particular stator shown and described is only one illustrative environment in which the apparatus of the invention may be employed. The apparatus may be employed with other types of stators. Furthermore, the description of the apparatus to follow is not intended to limit the combinations of configurations of the invention, but to describe the most detailed embodiment. Depending upon style of dynamoelectric device and customer requirements, certain features of the invention can be eliminated without departing from the scope of the invention.
[0016] The apparatus of the invention comprises a generally circular shroud that has a “U” shaped cross-section. In the preferred embodiment, the shroud is molded of an insulating plastic, although other materials may be used. The cross section is shaped to entirely contain the end turns and winding leads. The shroud is connected to an axial end of the stator assembly by means of stator slot posts, which are press fit into slots created by adjacent stator poles. Molded to the shroud is a terminal container to which the winding leads are attached. Molded into the shroud is a circuitry compartment that houses current and temperature sensing devices. Above the circuitry compartment is a protector cover to hold the temperature and current sensing devices inside the circuitry compartment. Across the protector cover is a clamp that holds the protector cover to the shroud.
[0017] The shroud can be fitted to both axially opposite ends of the stator assembly. When a shroud is fitted to both ends of the stator assembly, it is possible one shroud may be constructed without the terminal container, circuitry compartment, or protector cover.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Further objectives and features of the invention are revealed in the following detailed description of the preferred embodiment of the invention and in the drawing figures wherein:
[0019] [0019]FIG. 1 is an end view of an opened housing, exposing the stator poles and wire windings showing prior art methods of lacing end turns and grouping winding leads.
[0020] [0020]FIG. 2 is an exploded view of the apparatus of the invention.
[0021] [0021]FIG. 3 is an assembled view of the apparatus of the invention.
[0022] [0022]FIG. 4 is a view of the apparatus of the invention fully assembled on the stator assembly of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] [0023]FIGS. 2 and 3 show the apparatus of the invention that is basically comprised of a shroud 25 having a terminal container 26 , a terminal container top 28 , a circuitry compartment 30 , a protector cover 31 for the circuitry compartment 30 , and a clamp 32 for the protector cover 31 . The shroud 25 is made from a high temperature, insulating plastic and is formed with a “U”-shaped cross section. The “U”-shaped cross section of the shroud 25 consists of an outer diameter surface shown as the outer wall 36 and inner diameter surface shown as the inner wall 38 . The outer wall 36 and the inner wall 38 are connected via an annular end wall 40 . The inner wall 38 , outer wall 36 , and end wall 40 are molded as an integral piece, and the interior surface of the shroud's “U”-shaped cross section forms an annular channel 42 . This annular channel houses the winding leads 24 and end turns 16 shown in FIG. 1. In FIG. 4, the shroud 25 is shown installed on the stator assembly 22 of FIG. 1 with the winding leads 24 and end turns 16 fully contained within the annular channel 42 formed by the interior of the “U”-shaped cross section of the shroud.
[0024] In FIGS. 2 and 3, the shroud 25 has a plurality of arcuate slots 44 in the end wall 40 . The arcuate slots are radially centered on the end wall and circumferentially spaced in such a manner to provide structural integrity to the shroud 25 . The regular pattern of circumferential spacing of the arcuate slots 44 is interrupted in areas adjacent to the circuitry compartment 30 and the terminal container 26 . The slots provide the exterior surface of the end wall 40 with communication to the interior of the annular channel 42 . These arcuate slots 44 provide cooling paths from the end shields of the motor to the stator assembly 22 .
[0025] In FIGS. 2 and 3, the inner wall 38 of the shroud 25 is shown with axial slots 46 through the inner wall 38 and partially through the end wall 40 . The axial slots 46 are circumferentially spaced about the inner wall 38 , providing communication between both the exterior surfaces of the inner wall 38 and end wall 40 , and the annular channel 42 . These inner wall axial slots 46 provide additional cooling paths from the end shields of the motor to the stator assembly 22 . The circumferential spacing of the axial slots 46 is interrupted in areas adjacent to the circuitry compartment 30 and the terminal container 26 to maintain structural integrity of the shroud 25 in these areas.
[0026] In FIGS. 2 and 3, the outer wall 36 of the shroud 25 is shown with axial slots 48 through the outer wall 36 and partially through the end wall 40 . The axial slots 48 are circumferentially spaced about the outer wall 36 , providing communication between both the exterior surfaces of the outer wall 36 and end wall 40 , and the annular channel 42 . These outer wall axial slots 48 provide additional cooling paths from the end shields of the motor to the stator assembly 22 . The circumferential spacing of the axial slots 48 is interrupted in areas adjacent to the circuitry compartment 30 and the terminal container 26 to maintain structural integrity of the shroud 25 in these areas.
[0027] [0027]FIGS. 2, 3, and 4 show the terminal container 26 integrally molded with the shroud 25 . The terminal container 26 is dimensioned to project radially outward from the shroud 25 to a position outside the housing 20 when the shroud 25 is positioned in the housing. In this configuration, the housing is provided with a notch 50 to accommodate the terminal container 26 . However, the terminal container 26 may be molded to project axially from the shroud. In that configuration, a notch 50 in the housing 20 need not be provided. Winding leads 24 are directed to the terminal container 26 to facilitate connection to an external apparatus of the motor. The terminal container 26 is rigged with a system of plug and socket quick-disconnects that provides a standard connection system to other components of the motor. As shown in FIG. 4, a single terminal container connector 52 can be used as a standard interface to an external motor apparatus. The terminal container arrangement enables the stator assembly 22 of the motor to be completed in manufacture without the need for winding leads 24 to be sized for a specific terminal point or fitted with a specific connector.
[0028] In the shroud, in the area adjacent to the terminal container 26 , a terminal container arcuate slot 54 is provided in the end wall 40 . The terminal container arcuate slot 54 provides an opening for assembly operators to connect the winding leads 24 of FIG. 1 to the terminal points in the terminal container 26 . The terminal container 26 has a terminal container top 28 , which forms the external casing of the terminal container 26 . When removed, the terminal container top 28 exposes the inside of the terminal container and ports to which winding leads 24 of FIG. 1 can be connected. With the terminal container top 28 removed, assembly operators can connect winding leads to the terminals without a need to color code the ends of winding leads, and without the need to ensure the winding leads have sufficient length to connect to external motor apparatus. After connections are made to the required port inside the terminal container 26 , the terminal container top 28 snaps into place to form the external surface of the terminal container 26 . The terminal container top 28 can be removed to expose terminal connections and their ports for later testing and inspection without damaging winding leads or the protective sealant affixed thereon.
[0029] The circuitry compartment 30 is molded into the shroud 25 as a rectangular slot in the end wall 40 . Positioned above the circuitry compartment 30 is a protector cover 31 . The protector cover is a resilient member that has an “L”-shaped cross-section as seen in FIG. 2. The “L”-shaped cross section permits the protector cover 31 to span over the circuitry compartment 30 in a radial direction across the end wall 40 . With the protector cover 31 having a “L”-shaped cross section, the portion of the cover that spans over the circuitry compartment 30 can be resiliently flexed away from the circuitry compartment a short distance to permit insertion of the protective temperature and current limiting devices in the circuitry compartment. The protector cover 30 is firmly attached to the shroud 25 at the interface of the inner wall 38 and the end wall 40 so as to form an integral unit with the shroud 25 . At the interface of the outer wall 36 and the end wall 40 , the edge of the protector cover 31 is suspended above the end wall and the circuitry compartment 30 . The edge of the protector cover 31 is provided with a lip 56 that engages a side of the protector device 58 and holds it in place. As a rectangular slot in the end wall 40 , the circuitry compartment 30 provides communication between the exterior surface of the end wall 40 and the annular channel 42 .
[0030] As shown in FIG. 4, the circuitry compartment 30 and protector cover 31 serve as a storage location for standard protective temperature and current sensing devices 58 . Depending on the particular device intended to be used with the stator, the shape and size of the circuitry compartment would change to accommodate the device. Recessed shoulders 60 are formed inside the circuitry compartment at circumferentially opposite ends of the circuitry compartment. The recessed shoulders 60 provide seating surfaces for the temperature and current sensing devices 58 . With this arrangement, the device 58 is held in place inside the circuitry compartment 30 and on top of the recessed shoulders 60 by the protector cover 31 , while the opening between the recessed shoulders 60 of the circuitry compartment 30 provides a passage for directing the leads or other types of connections of the temperature and current sensing device 58 into the annular channel 42 and to the windings of the stator. The device 58 can be installed in the shroud 25 by lifting up the protector cover 31 and placing the device in the circuitry compartment 30 . Preferably, the device is held in place in the circuitry compartment by the resiliency of the protector cover.
[0031] To ensure the positive location of the contents of the circuitry compartment 30 , a clamp 32 is used to hold down the suspended edge of the protector cover 31 . The clamp 32 is configured in a general “U”-shape and is fully detachable from the shroud 25 . The clamp 32 has a hook 62 on one end used to anchor the clamp to the shroud at the exposed edge of the inner wall 38 . On the other end, the clamp 32 is configured with a series of barbs 64 that enable the clamp to be anchored to the exposed edge of the outer wall 36 .
[0032] In FIGS. 2 and 3, a plurality of stator slot posts 66 are shown projecting axially away from the shroud 25 . The posts are integral with the shroud and connected at the exposed edge of the inner wall 38 . The stator slot posts 66 are circumferentially spaced so as to engage inside several of the slots between the stator poles on the stator assembly 22 . The length of the stator slot posts 66 is determined to provide radial support and alignment of the shroud 25 with the stator assembly 22 . The radial thickness of the stator slot posts is set so as not to interfere with the stator bore or the annular channel 42 .
[0033] While the present invention has been described by reference to a specific embodiment, it should be understood that modifications and variations of the invention may be constructed without departing from the scope of the invention defined in the following claims. | A shroud is provided for a dynamoelectric device such as an electric motor comprising a rotor and a wire wound stator, where the shroud fully contains the end turns of the stator wire windings, provides terminal connections for winding leads, and includes a circuitry compartment to house a temperature and current protective device. | 7 |
This is a continuation-in-part (CIP) of U.S. patent application Ser. No. 10/288,706, filed Nov. 6, 2002, now U.S. Pat. No. 6,623,259 as amended.
FIELD OF THE INVENTION
The invention relates generally to high-pressure plunger pumps used, for example, in oil field operations. More particularly, the invention relates to valve guides and spring retainers for use in plunger pump housings that incorporate structural features for stress-relief and for accommodating valve guide and/or spring retainer assemblies.
BACKGROUND
Engineers typically design high-pressure oil field plunger pumps in two sections; the (proximal) power section and the (distal) fluid section. The power section usually comprises a crankshaft, reduction gears, bearings, connecting rods, crossheads, crosshead extension rods, etc. Commonly used fluid sections usually comprise a plunger pump housing having a suction valve in a suction bore, a discharge valve in a discharge bore, an access bore, and a plunger in a plunger bore, plus high-pressure seals, etc. FIG. 1 is a cross-sectional schematic view of a typical fluid section showing its connection to a power section by stay rods. A plurality of fluid sections similar to that illustrated in FIG. 1 may be combined, as suggested in the Triplex fluid section design schematically illustrated in FIG. 2 .
Valve terminology varies according to the industry (e.g., pipeline or oil field service) in which the valve is used. In some applications, the term “valve” means just the moving element or valve body, whereas the term “valve” as used herein includes the valve body, the valve seat, one or more valve guides to control the motion of the valve body, and one or more valve springs that tend to hold the valve closed (i.e., with the valve body reversibly sealed against the valve seat).
Each individual bore in a plunger pump housing is subject to fatigue due to alternating high and low pressures which occur with each stroke of the plunger cycle. Plunger pump housings typically fail due to fatigue cracks in one of the areas defined by the intersecting suction, plunger, access and discharge bores as schematically illustrated in FIG. 3 .
To reduce the likelihood of fatigue cracking in the high pressure plunger pump housings described above, a Y-block housing design has been proposed. The Y-block design, which is schematically illustrated in FIG. 4 , reduces stress concentrations in a plunger pump housing such as that shown in FIG. 3 by increasing the angles of bore intersections above 90°. In the illustrated example of FIG. 4 , the bore intersection angles are approximately 120°. A more complete cross-sectional view of a Y-block plunger pump fluid section is schematically illustrated in FIG. 5 .
Although several variations of the Y-block design have been evaluated, none have become commercially successful for several reasons. One reason is that mechanics find field maintenance on Y-block fluid sections difficult. For example, replacement of plungers and/or plunger packing is significantly more complicated in Y-block designs than in the earlier designs represented by FIG. 1 . In the earlier designs, provision is made to push the plunger distally through the cylinder bore and out through an access bore (labeled the suction valve/plunger cover in FIG. 1 ). This operation, which would leave the plunger packing easily accessible from the proximal end of the cylinder bore, is impossible in a Y-block design.
Thus the Y-block configuration, while reducing stress in a plunger pump housing relative to earlier designs, is associated with significant disadvantages. However, new high pressure plunger pump housings that provide both improved internal access and superior stress reduction are described in copending U.S. patent application Ser. No. 10/288,706, as amended, which is incorporated herein by reference (hereinafter the '706 application). One embodiment of the invention of the '706 application is schematically illustrated in FIG. 6 . It includes a right-angular plunger pump housing comprising a suction valve bore (suction bore), discharge valve bore (discharge bore), plunger bore and access bore. The suction and discharge bores each have a portion with substantially circular cross-sections for accommodating a valve body and valve seat with substantially circular cross-sections. Note that the illustrated portions of the suction and discharge bores that accommodate a valve seat are slightly conical to facilitate substantially leak-proof and secure placement of each valve seat in the pump housing (e.g., by press-fitting). Less commonly, the portions of suction and discharge bores intended to accommodate a valve seat are cylindrical instead of being slightly conical. Further, each bore (i.e., suction, discharge, access and plunger bores) comprises a transition area for interfacing with other bores.
The plunger bore of the right-angular plunger pump housing of FIG. 6 comprises a cylinder bore having a proximal packing area (i.e., an area relatively nearer the power section) and a distal transition area (i.e., an area relatively more distant from the power section). Between the packing and transition areas is a right circular cylindrical area for accommodating a plunger. The transition area of the cylinder bore facilitates interfaces with analogous transition areas of other bores as noted above.
Each bore transition area of the right-angular pump housing of FIG. 6 has a stress-reducing feature comprising an elongated (e.g., elliptical or oblong) cross-section that is substantially perpendicular to each respective bore's longitudinal axis. Intersections of the bore transition areas are chamfered, the chamfers comprising additional stress-reducing features. Further, the long axis of each such elongated cross-section is substantially perpendicular to a plane that contains, or is parallel to, the longitudinal axes of the suction, discharge, access and cylinder bores.
An elongated suction bore transition area, as described in the '706 application, can simplify certain plunger pump housing structural features needed for installation of a suction valve (including its valve spring and valve spring retainer). Specifically, the valve spring retainer of a suction valve installed in such a plunger pump housing does not require a retainer arm projecting from the housing. Nor do threads have to be cut in the housing to position the retainer that secures the suction valve seat. Benefits arising from the absence of a suction valve spring retainer arm include stress reduction in the plunger pump housing and simplified machining requirements. Further, the absence of threads associated with a suction valve seat retainer in the suction bore eliminates the stress-concentrating effects that would otherwise be associated with such threads.
Threads can be eliminated from the suction bore if the suction valve seat is inserted through the suction bore transition area and press-fit into place as described in the '706 application. Following this, the suction valve body can also be inserted through the suction bore transition area. Finally, a valve spring is inserted via the suction bore transition area and held in place by an oblong suction valve spring retainer, an example of which is described in the '706 application. Note that the '706 application illustrates an oblong suction valve spring retainer having a guide hole (for a top-stem-guided valve body), as well as an oblong suction valve spring retainer without a guide hole (for a crow-foot-guided valve body). Both of these oblong spring retainer embodiments are secured in a pump housing of the '706 application by clamping about an oblong lip, the lip being a structural feature of the housing (see FIG. 6 ).
The '706 application also shows how discharge valves can be mounted in the fluid end of a high-pressure pump incorporating positive displacement pistons or plungers. For well service applications both suction and discharge valves typically incorporate a traditional full open seat design with each valve body having integral crow-foot guides. This design has been adapted for the high pressures and repetitive impact loading of the valve body and valve seat that are seen in well service. However, stem-guided valves with full open seats could also be considered for well service because they offer better flow characteristics than traditional crow-foot-guided valves. But in a full open seat configuration stem-guided valves require guide stems on both sides of the valve body (i.e., “top” and “lower” guide stems) to maintain proper alignment of the valve body with the valve seat during opening and closing. Unfortunately, designs incorporating secure placement of guides for both top and lower valve guide stems have been associated with complex components and difficult maintenance.
SUMMARY OF THE INVENTION
The current invention includes methods and apparatus related to valve stem guide and spring retainer assemblies and to plunger pump housings in which they are used. Typically, such plunger pump housings incorporate one or more of the stress-relief structural features described herein, plus one or more additional structural features associated with use of valve stem guide and spring retainer assemblies in the housings.
Examples of plunger pump housings incorporating such stress-relief structural features comprise substantially right-angular housings having substantially in-line (i.e., opposing) suction and discharge bores, plus substantially in-line (i.e., opposing) plunger and access bores. Where indicated as being collinear and/or coplanar, bore centerlines (or longitudinal axes) may vary somewhat from these precise conditions, due for example to manufacturing tolerances, while still substantially reflecting advantageous structural features of the present invention. The occurrence of such variations in certain manufacturing practices means that plunger pump housing embodiments of the present invention may vary somewhat from a precise right-angular configuration. Such plunger pump housings substantially reflect advantageous structural features of the present invention notwithstanding angles between the centerlines or longitudinal axes of adjacent bores that are within a range from approximately 85 degrees to approximately 95 degrees. Where the lines and/or axes forming the sides of such an angle to be measured are not precisely coplanar, the angle measurement is conveniently approximated using projections of the indicated lines and/or axes on a single plane in which the projected angle to be approximated is maximized.
Illustrated embodiments of valve stem guide and spring retainer assemblies of the present invention include, for example, a combination comprising structures to facilitate a discharge valve lower stem guide (DVLSG) function, plus a suction valve top stem guide and spring retainer (SVTSG-SR) function, plus a spacing function for spacing the DVLSG structures a predetermined distance apart from the SVTSG-SR structures. Alternative embodiments of the invention comprise other combinations of structural features to facilitate, for example, spring retainer and spacing functions with or without associated valve guide functions.
An illustrated embodiment of a plunger pump housing for use with valve stem guide and spring retainer assemblies of the present invention comprises a suction valve bore having a portion with substantially circular cross-sections for accommodating a circular suction valve, a cylindrical transition area, a shoulder corresponding to a suction valve top stem guide and spring retainer shoulder mating surface, and a first centerline. Analogously, a discharge valve bore has a portion with substantially circular cross-sections for accommodating a circular discharge valve, a cylindrical transition area, a shoulder corresponding to a discharge valve lower stem guide shoulder mating surface, and a second centerline. The first and second centerlines are collinear.
Illustrated embodiments of a plunger pump housing for use with valve stem guide and spring retainer assemblies of the present invention also comprise a cylinder bore having a proximal packing area and a distal transition area, the packing area having a substantially circular cross-section and a third centerline. The third centerline is coplanar with the first and second centerlines.
Illustrated embodiments of a plunger pump housing for use with valve stem guide and spring retainer assemblies of the present invention further comprise an access bore having a portion with substantially circular cross-sections for accommodating an access bore cover plug retainer, as well as a cylindrical transition area with elongated cross-sections that facilitates access to interior portions of the plunger pump housing. The access bore has a fourth centerline that is colinear with the third centerline.
Illustrated embodiments show that the suction valve bore transition area has an elongated cross-section substantially perpendicular to the first centerline and with a long axis substantially perpendicular to a plane containing the first, second, third and fourth centerlines. Analogously, the discharge valve bore transition area has an elongated cross-section substantially perpendicular to the second centerline and with a long axis substantially perpendicular to a plane containing the first, second, third and fourth centerlines. Analogously, the cylinder bore transition area has elongated cross-sections substantially perpendicular to said third centerline and with a long axis substantially perpendicular to a plane containing said first, second, third and fourth centerlines. And analogously, the access bore transition area has elongated cross-sections substantially perpendicular to said fourth centerline, each said elongated access bore cross-section having a long axis substantially perpendicular to a plane containing said first, second, third and fourth centerlines. Note that each said bore transition area has at least one adjacent chamfer for smoothing bore interfaces.
A valve stem guide and spring retainer assembly of the present invention can be used in the above plunger pump housing. The assembly comprises a discharge valve lower stem guide (DVLSG) for placement substantially within a discharge bore transition area of the plunger pump housing, said DVLSG comprising a body having first and second ends and a transverse cross-section. The first end of the DVLSG body comprises a shoulder mating surface for mating with a corresponding shoulder within the discharge bore, and the second end of the DVLSG body comprises at least one lateral alignment groove, a centered cylindrical guide stem hole extending longitudinally between said first and second ends, and at least one fluid passage extending longitudinally between said first and second ends. As illustrated herein, the corresponding shoulder within the discharge bore is located at the junction of the portion having substantially circular cross-sections with the discharge bore's cylindrical transition area.
The above valve stem guide and spring retainer assembly further comprises a suction valve top stem guide and spring retainer (SVTSG-SR) for placement substantially opposite the above DVLSG and aligned with a suction bore transition area of the above plunger pump housing. The SVTSG-SR comprises a body having first and second ends and a transverse cross-section. The SVTSG-SR first end comprises a shoulder mating surface for mating with a corresponding shoulder within said suction bore, or a chamfer mating surface for mating with a chamfer adjacent to the suction bore. The SVTSG-SR second end comprises at least one lateral alignment groove for placement opposing said at least one DVLSG alignment groove to form at least one opposing lateral alignment groove pair. A centered cylindrical guide stem hole may be provided to accommodate a valve body's top guide stem. This guide stem hole extends longitudinally between said first and second SVTSG-SR ends. For applications not involving a valve body having a top guide stem (e.g., for use with a valve body having integral crow-foot guides), this guide stem hole may be eliminated. At least one fluid passage extends longitudinally between said first and second SVTSG-SR ends. As illustrated herein, the corresponding shoulder within the suction bore is located at the junction of the portion having substantially circular cross-sections with the suction bore's cylindrical transition area.
The above valve stem guide and spring retainer assembly further comprises at least one side spacer having first and second parallel edges for insertion between grooves of the above at least one opposing lateral alignment groove pair. The first and second parallel edges are spaced apart sufficiently to assure that, upon insertion, simultaneous mating between shoulder mating surfaces of the DVLSG and shoulder or chamfer mating surfaces of the SVTSG-SR and corresponding pump housing shoulders or chamfers when the valve stem guide and spring retainer assembly is used in the above plunger pump housing.
Note that the DVLSG and the SVTSG-SR each have transverse cross-sections dimensioned to allow a close longitudinal sliding fit within, respectively, a corresponding oblong cylindrical discharge bore transition area and a corresponding oblong cylindrical suction bore transition area of the above plunger pump housing. Note also that each side spacer may be dimensioned to fit closely between the plunger pump housing and a plunger inserted for use within the housing. As further explained below, such close fitting of each side spacer can improve a pump's volumetric efficiency.
The above valve stem guide and spring retainer assembly is schematically illustrated with two lateral alignment groove pairs and two side spacers. Also illustrated is an access bore cover plug for covering the access bore. As illustrated herein, two side spacers may be attached to the access bore cover plug to hold them in position (i.e., spaced a predetermined distance apart as shown) for easy insertion between opposing lateral alignment groove pairs, or one or both side spacers may be unattached to the access bore cover plug.
Alternative embodiments of the present invention are disclosed below with reference to appropriate drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional schematic view of a conventional plunger pump fluid section housing showing its connection to a power section by stay rods.
FIG. 2 schematically illustrates a conventional Triplex plunger pump fluid section.
FIG. 3 is a cross-sectional schematic view of suction, plunger, access and discharge bores of a conventional plunger pump housing intersecting at right angles showing areas of elevated stress.
FIG. 4 is a cross-sectional schematic view of suction, plunger and discharge bores of a Y-block plunger pump housing intersecting at obtuse angles showing areas of elevated stress.
FIG. 5 is a cross-sectional schematic view similar to that in FIG. 4 , including internal plunger pump components.
FIG. 6 schematically illustrates a cross-section of a right-angular plunger pump housing of the '706 application with valves, plunger, and a suction valve spring retainer clamped about a lip of the housing.
FIG. 7A schematically illustrates a cross-section of a right-angular plunger pump housing of the present invention. Note the absence of the housing lip shown in FIG. 6 , as well as other structural differences described below.
FIG. 7B schematically illustrates the sectional view labeled B—B in FIG. 7A .
FIG. 8A schematically illustrates a cross-section of a right-angular plunger pump housing analogous to that of FIG. 7A , but including a plunger and stem-guided suction and discharge valves, a DVLSG and a SVTSG-SR with shoulder mating surfaces, plus a flanged oblong access bore cover-plug with attached side spacer inserted in the access bore.
FIG. 8B schematically illustrates the sectional view labeled B—B in FIG. 8A .
FIG. 8C schematically illustrates the transverse section labeled C—C in FIG. 8B .
FIG. 8D schematically illustrates the transverse section labeled D—D in FIG. 8B .
FIG. 8E schematically illustrates the transverse section labeled E—E in FIG. 8B .
FIG. 8F schematically illustrates the transverse section labeled F—F in FIG. 8B .
FIG. 9A schematically illustrates a cross-section of a right-angular plunger pump housing analogous to that of FIG. 8A , but including a non-flanged oblong access bore cover-plug with attached side spacer inserted in the access bore.
FIG. 9B schematically illustrates the cross-section labeled B—B in FIG. 9A , showing a non-flanged oblong access bore cover-plug with attached side spacer having a shoulder mating surface, as well as the corresponding pump housing shoulder.
FIG. 10A schematically illustrates a cross-section of a right-angular plunger pump housing, together with a plunger and stem-guided suction and discharge valves, a DVLSG with shoulder mating surface, and a SVTSG-SR with chamfer mating surface, plus a flanged oblong access bore cover-plug with attached side spacer inserted in the access bore.
FIG. 10B schematically illustrates the sectional view labeled B—B in FIG. 9A .
FIG. 10C schematically illustrates the sectional view labeled C—C in FIG. 9B .
FIG. 10D schematically illustrates the sectional view labeled D—D in FIG. 9B .
FIG. 11A schematically illustrates an end view of a flanged oblong access bore cover-plug with attached side spacers (see FIG. 8A ).
FIG. 11B schematically illustrates the sectional view labeled B—B in FIG. 11A .
FIG. 11C schematically illustrates a side elevation of the oblong access bore cover-plug with attached side spacer shown in FIG. 11A .
FIG. 12A schematically illustrates an end view of a flanged oblong access bore cover-plug with separate side spacers.
FIG. 12B schematically illustrates the sectional view labeled B—B in FIG. 12A .
FIG. 12C schematically illustrates a side elevation of the oblong access bore cover-plug with separate side spacer shown in FIG. 12A .
FIG. 13A schematically illustrates an end view of a non-flanged oblong access bore cover-plug with attached side spacers (see FIGS. 9A and 9B ).
FIG. 13B schematically illustrates the sectional view labeled B—B in FIG. 13A .
FIG. 13C schematically illustrates a side elevation of the oblong access bore cover-plug with separate side spacer shown in FIG. 13A .
FIG. 14 schematically illustrates a cross-section of the right-angular plunger pump housing of FIG. 7A , together with a plunger and crow-foot-guided suction and discharge valves, a discharger valve stem guide body, and a suction valve spring retainer with chamfer mating surfaces, plus a flanged oblong access bore cover-plug with attached side spacer inserted in the access bore.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 7A and 7B schematically illustrate cross-sections of a right-angular pump housing 450 of the present invention, including a plunger bore 408 with its transition area 409 , a suction bore 410 with its transition area 405 , an access bore 411 with its transition area 406 and a discharge bore 412 with its transition area 407 . The right-angular housing of FIG. 7A is analogous to that in FIG. 6 , but without the housing lip shown securing the suction valve spring retainer in FIG. 6 . While this lip has an oblong shape to reduce stress in the area near the lip, stress can be reduced even more if the lip is eliminated entirely and replaced by an oblong cylindrical transition area as seen in FIG. 8C , 8 E or 10 C. As described herein, valve guide and spring retainer assemblies of the present invention are designed in ways that reduce stress by eliminating the need for the lip.
The chamfers 460 , 461 , 462 and 463 shown in FIG. 7A are also stress-reducing features in pump housing 450 of the present invention. As schematically illustrated, these chamfers indicate portions of a barrel-shaped space that has been machined from the interior during manufacture of the pump housing 450 . For clarification, the profile of this barrel-shaped space (barrel profile) is shown in heavy broken lines on FIG. 7A and discussed further below. Note that this space, which is shown as having a longitudinal axis coincident with the (vertical) centerline passing through the suction and discharge bores, has transverse cross-sections that are circular. Note also that machining the schematically illustrated barrel profile about the vertical centerline results in larger (i.e., more beneficial) barrel radii than machining an analogous (but smaller) barrel profile about the horizontal centerline (which is shown coincident with the common centerline of the access and plunger bores). Further, machining about either the horizontal or vertical centerlines as above produces more consistently beneficial results than the common industry practice of localized chamfering (e.g., chamfering about one or more axes laterally displaced from the respective centerlines).
While it is common design practice to generally call for chamfers at bore intersections, the radii of these chamfers cannot be reliably optimized by using rule-of-thumb approximations. Finite element analysis (FEA), on the other hand, provides means to quantify the benefits of, for example, using relatively larger barrel machining radii in the present invention. FEA shows that while use of the larger barrel radii removes relatively more material from the housing, it does not unduly increase stress elsewhere within the housing. In fact, modern computer-based FEA algorithms show that overall pump housing stress can be significantly reduced by the chamfers resulting from machining the relatively large internal barrel profile of the present invention.
This result is surprising because conventional wisdom suggests that removing material from the pump housing would tend to increase stress due to reduced wall thickness, and that removing more material would be associated with further increased housing wall stress. But FEA shows that for chamfers of the present invention the opposite is true. In fact, use of the large barrel profile allows for large chamfers, cut with relatively long radii, that both remove pump housing material and reduce stress in the high stress areas of the housing.
These combined benefits are obtained because the relatively large radii of the barrel machining profile result in removal of relatively large amounts of material from areas of the pump housing where stress is relatively low. Thus, there is little tendency for significant amounts of stress to be shifted to other parts of the pump housing. Note, however, that use of a large internal barrel machining profile as described above increases the amount of internal pump housing space that is not swept by movement of the plunger. And additional unswept internal pump housing space tends to reduce volumetric efficiency. As further described herein, however, this increase in unswept volume is effectively countered through use of side-spacers of the present invention to space apart a DVLSG and a SVTSG-SR, or to space apart a DVLSG and a suction valve spring retainer.
FIGS. 8A and 8B schematically illustrate a right-angular pump housing 450 of the present invention which is analogous to the housing of FIGS. 7A and 7B but includes a plunger in cylinder bore 408 , a stem-guided suction valve in suction valve bore 410 , an oblong access bore cover plug 400 with attached side spacers 401 in access bore 411 , and a stem-guided discharge valve in discharge valve bore 412 . Additional structures shown in FIGS. 8A and 8B include a DVLSG body 420 and a SVTSG-SR body 440 .
FIG. 8B shows the shoulder mating surfaces 421 and 441 on the respective first ends 425 and 445 of DVLSG body 420 and SVTSG-SR body 440 . The respective second ends 426 and 446 of DVLSG body 420 and SVTSG-SR body 440 are seen to have opposing lateral alignment grooves 423 and 443 respectively forming two opposing lateral alignment groove pairs. Also seen in FIG. 8B are discharge bore shoulder 422 of pump housing 450 corresponding to DVLSG shoulder mating surface 421 , as well as suction bore shoulder 442 of pump housing 450 corresponding to SVTSG-SR shoulder mating surface 441 .
FIGS. 8A and 8B also show a cylindrical transition area 405 of suction valve bore 410 in which SVTSG-SR body 440 has a close longitudinal sliding fit. Analogously, FIGS. 8A and 8B also show a cylindrical transition area 407 of discharge valve bore 412 in which DVLSG body 420 has a close longitudinal sliding fit. Transition area 409 and packing area 404 of cylinder bore 408 , plus transition area 406 of access bore 411 are shown in FIG. 8A , as are chamfers 460 and 461 adjacent to cylinder bore 408 , chamfers 461 and 462 adjacent to suction valve bore 410 , chamfers 462 and 463 adjacent to access bore 411 , and chamfers 463 and 460 adjacent to discharge valve bore 412 .
FIG. 8B shows centered cylindrical guide stem hole 424 and fluid passages 427 extending longitudinally between first end 425 and second end 426 of DVLSG body 420 . Analogously, FIG. 8B shows centered cylindrical guide stem hole 444 and fluid passages 447 extending longitudinally between first end 445 and second end 446 of SVTSG-SR body 440 . Also shown in FIG. 8B are two side spacers 401 with parallel edges 402 and 403 , each side spacer 401 being for insertion between an opposing lateral alignment groove pair comprising a lateral alignment groove 423 in second end 426 of DVLSG body 420 opposite a lateral alignment groove 443 in second end 446 of SVTSG-SR body 440 .
FIG. 8C schematically illustrates the transverse section labeled C—C in FIG. 8B . FIG. 8D schematically illustrates the transverse section labeled D—D in FIG. 8B . FIG. 8E schematically illustrates the transverse section labeled E—E in FIG. 8B . FIG. 8F schematically illustrates the transverse section labeled F—F in FIG. 8B . FIG. 8C shows lateral alignment grooves 443 and fluid passages 447 . FIG. 8D shows lateral alignment grooves 423 and fluid passages 427 . FIGS. 8E and 8F show fluid passages 447 and 427 respectively. Compare the routes for fluid flow through, and on either side of, passages 447 and 427 (see FIGS. 8E and 8F respectively) with the more streamlined fluid flow routes through passages 547 and 527 (see FIGS. 10C and 10D respectively). Note, however, that a more significant reduction in fluid flow resistance in the embodiment of FIGS. 10A–D , relative to the embodiment of FIGS. 8A–F , is obtained because use of the chamfer mating surface 541 obviates the need for shoulder mating surface 441 . Shoulder mating surface 441 , when present, is relatively close to the suction valve body, so elimination of shoulder mating surface 441 increases the cross-sectional flow area near the suction valve body and causes a significant reduction in flow resistance for fluid flowing around the suction valve body.
FIGS. 9A and 9B schematically illustrate an alternative right-angular plunger pump housing 449 having an internal shoulder 470 for mating with shoulder mating surfaces 471 of side spacers 401 which are attached to non-flanged oblong access bore cover plug 600 (see FIGS. 13A , 13 B and 13 C). The lack of a flange on access bore cover plug 600 means that when internal pressure in plunger pump housing 449 is reduced (e.g., during a plunger's suction stroke), the tendency for cover plug 600 to be drawn further into housing 449 is resisted by contact between shoulder mating surfaces 471 and shoulder 470 of housing 449 .
Thus, elimination of the flange on an access bore cover plug simultaneously eliminates a source of stress on the cover plug and a source of stress on the portion of the pump housing that would otherwise interface with the cover plug flange. And besides reducing stress on the cover plug, elimination of the flange makes the cover plug easier to machine. Further, a reduction of stress on the pump housing means that its design may be altered to require less material for its manufacture.
FIGS. 10A and 10B schematically illustrate an alternative right-angular pump housing 451 of the present invention, analogous to pump housing 450 as shown in FIGS. 8A and 8B . Structural differences between pump housing 451 and 450 , include the presence of recesses 465 which accommodate relatively thicker side spacers 501 with their parallel edges 502 and 503 . Note also that parallel edges 502 and 503 are shaped differently (see FIG. 10B ) from analogous parallel edges 402 and 403 of side spacers 401 (see FIG. 8B ). Lateral alignment grooves 523 and 543 of SVTSG-SR body 540 (see FIG. 9B ) accommodate parallel edges 502 and 503 in a manner analogous to accommodation of parallel edges 402 and 403 in lateral alignment grooves 423 and 443 (see FIG. 8B ).
Another difference between the embodiment illustrated in FIGS. 8A and 8B compared to the embodiment illustrated in FIGS. 10A and 10B is in the structure of SVTSG-SR body 540 . As shown in FIG. 10A , SVTSG-SR body 540 comprises a chamfer mating surface 541 instead of the shoulder mating surface 441 illustrated on SVTSG-SR body 440 in FIG. 8B . While either chamfer mating surface 541 or shoulder mating surface 441 facilitates aligning its respective SVTSG-SR body with respect to its respective suction bore, various pump operational parameters (e.g., flow rate or pressure), as well as particulars of manufacturing techniques (e.g., materials or heat treatments) may favor the use of a shoulder mating surface or a chamfer mating surface for a specific application. Note that the technique of suction bore chamfer mating in lieu of suction bore shoulder mating, as described above for pump housing 451 , can be analogously applied for pump housing 450 .
Regardless of the use of either suction bore chamfer mating or suction bore shoulder mating in a pump housing of the present invention, the spacing function of either embodiment 401 or 501 of side spacers remains as described herein. This function is accomplished whether side spacers are attached to a flanged access bore cover plug (see, e.g., plug 400 in FIGS. 11A–11C ), or a non-flanged access bore cover plug (see, e.g., plug 600 in FIGS. 13A–13C ), or are separated from an access bore cover plug (see, e.g., plug 400 ′ in FIGS. 12A–12C ).
Side spacers 501 are dimensioned to fit more closely between a plunger and the pump housing 451 (that is, to occupy more of the space between a plunger and the pump housing 451 ) relative to the analogous fit between a plunger and the pump housing 450 . Note that FIG. 10B illustrates the portion of total internal space not swept by a plunger (unswept space) within pump housing 451 as being relatively smaller than the analogous unswept space illustrated in FIG. 8B . Thus, the ratio of swept space to total internal space (i.e., swept space plus unswept space) is relatively larger for pump housing 451 in FIG. 10B compared to the analogous ratio for pump housing 450 in FIG. 8B . The difference in these ratios means that the embodiment schematically represented in FIG. 10B has greater volumetric efficiency than the embodiment schematically represented in FIG. 8B .
As illustrated herein, each side spacer intended for use in a pump housing of the present invention may comprise a longitudinal concave surface having a slightly greater radius of curvature, and an extension of the same center line of curvature when in its functional position in a pump housing, as that of the right circular cylindrical portion of the plunger bore. The spacer is thus located so as to effectively longitudinally extend the right circular cylindrical portion of the plunger bore into the internal space of a pump housing on which the suction, discharge and access bore transition areas open. When so located, each side spacer occupies space that would otherwise comprise part of the volume within the pump housing which is unswept by the plunger. So each side spacer, when located in its functional position in a pump housing, effectively reduces the unswept volume of that housing and thereby increases the volumetric efficiency of the pump while simultaneously accomplishing its function of spacing apart the DVLSG and the SVTSG-SR (or the suction valve spring retainer in embodiments for use with valve bodies having integral crow-foot guides but no top guide stems). Side spacers secure stem guides and spring retainers in place by maintaining sufficient distance between their respective mating surfaces (e.g., between the shoulder mating surface of the DVLSG and either the shoulder mating surface or the chamfer mating surface of the SVTSG-SR). Volumetric efficiency is further enhanced when each side spacer is dimensioned to mate closely with the adjacent internal portions of pump housings of the present invention (see, e.g., FIG. 10B ).
In the embodiments illustrated in FIGS. 8A , 8 B, 10 A and 10 B, the DVLSG and the SVTSG-SR each have an elongated transverse cross-section, and they are dimensioned to allow a close sliding fit within, respectively, the cylindrical elongated discharge bore transition area and the cylindrical elongated suction bore transition area of a stress-relieved plunger pump housing. Further, the DVLSG and the SVTSG-SR each comprise a centered cylindrical longitudinal valve stem guide hole and at least one longitudinal fluid passage, each said fluid passage functioning to facilitate substantially longitudinal fluid flow through the DVLSG and the SVTSG-SR respectively. Note, however, that the use of a crow-foot guided suction valve body in a pump housing of the present invention (see FIG. 14 ) may obviate the need for centered cylindrical guide stem holes such as holes 424 and 444 in FIGS. 8A and 8B . If present in a suction valve spring retainer body such as 640 (see FIG. 14 ) or in a discharge valve stem guide body used with a crow-foot guided discharge valve (again see FIG. 14 ), such holes may function instead to further facilitate longitudinal fluid flow through the associated suction valve. Note also that use of a chamfer mating surface on a suction valve spring retainer as shown in FIG. 14 more significantly decreases longitudinal fluid flow resistance in the suction bore by eliminating the shoulder mating surface from the vicinity of the suction valve body (thus increasing fluid flow cross-sectional area in the vicinity of the suction valve body). | Valve guide and spring retainer assemblies are described for use in plunger pump housings that incorporate structural features for stress-relief. These pump housing structural features accommodate correspondingly-shaped valve guides and/or spring retainers that are internally fixed in place using one or more non-threaded spacers. Plunger pumps so constructed are relatively resistant to fatigue failure because of stress reductions, and they may incorporate a variety of valve styles, including top and lower stem-guided valves and crow-foot-guided valves, in easily-maintained configurations. Besides securing valve guides and/or spring retainers, non-threaded spacers may be shaped and dimensioned to aid in further reducing stress and to improve volumetric efficiency of the pumps in which they are used. | 5 |
[0001] This application claims priority to U.S. Provisional Patent No. 61/782,519, to Gustayson et al., filed on Mar. 14, 2013, and entitled “SYSTEM FOR MANAGING REMOTE SOFTWARE APPLICATIONS.”
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates generally to methods and systems for managing remote software applications. Specifically providing a unified login experience to applications and management of application login credentials.
[0004] 2. Description of the Related Art
[0005] Software-as-a-Service (SaaS) is a method for software deployment or delivery using the Internet, internal corporate network or similar networks. This software is generally centrally hosted, either by a service provider or by an organization. Under SaaS, a software provider licenses a software application (App) to clients for use on demand. Basic access to an App might be free of charge or with a fee. SaaS allows the provider to develop, host and operate a software application, for use by clients, who use a computer or smart device with internet access to download, if required, and run the software application and/or to access a host via a web browser or similar thin-client to run the software application. The App can be licensed to single user (one-user, one-account) or a group of users or an organization, and each user account may have many clients and/or client sessions (shared account). Some current examples of Apps include Amazon Web Services, Google Apps, Salesforce.com, Concur Travel & Expense, and Twitter.
[0006] As popularity of the SaaS model has grown, modern organizations and employees, such as individual knowledge workers, rely on an increasing number of services and Apps. Each App is typically secured with its own username and password combination, requiring users and/or organizations to keep track of the many combinations. These passwords are frequently stored insecurely, often scribbled on Post-It notes on monitors, or held in shared spreadsheets.
[0007] It is also common in some Apps to have one account that is shared by multiple users. For example, an organization will typically have one Twitter account, which will be updated and managed by many staff members. To access the account, each staff member will need to be given the username and password. This creates security concerns when a staff member leaves the organization, at which point the organization wishes to revoke the ex-member's access. This often necessitates creating a new password, which then must be redistributed to all active staff members (who then typically update their Post-It notes). The shared account and password model also complicates the use of contractors or consultants, for concerns over sharing passwords with temporary team members or outside organizations, and subsequent access revocation and password resetting.
[0008] Managing Apps with the one-user one-account model is also complicated for organizations, requiring significant time from IT administrators to setup accounts for large departments or organizations when a new App is rolled out to the organization. On-going maintenance is also challenging, as administrators try to keep, add or remove App accounts when members join and leave the organization.
[0009] Additionally, organizations typically have little to no information about which members access which Apps or when. This prevents the organizations from having traceable audit trails, required by many licensing bodies.
[0010] Existing Apps typically provide services in a one-to-one relationship with the end user, a relationship with the end user's systems and/or with the end user's organization. Integration between an end user's systems and Apps or between an end user's Apps requires pre-arranged coordination and configuration by all parties. Additionally, the Apps are not aware of each other and have no mechanism to communicate or coordinate without the participation and pre-arranged coordination of the end user and/or the end user's organization.
[0011] For example, an organization might store data in a remote spreadsheet service (for example, “Google Docs” or “Windows 365”) and want to import that data into a customer relationship management (CRM) service or marketing automation service (for example, Salesforce.com or Marketo.com, respectively). Presently, each of the mentioned services would require direct integration effort to work together, potentially involving four distinct integrations as follows: (i) Google Docs to Marketo, (ii) Google Docs to Salesforce.com, (iii) Windows 365 to Marketo, (iv) Windows 365 to Salesforce.com. The problem grows as more Apps require integration with each other and when multiple Apps simultaneously require integration with each other.
[0012] A further example would be moving press release content from a content management system (CMS) (for example, wordpress.com, squarespace.com, or tumblr.com) and sending that data to a social media service or social media management service (examples: twitter.com, facebook.com, Google+, hootsuite.com, cotweet.com, buddymedia.com). The listed examples would involve 18 different integration points—the number of integrations rises exponentially with the number of integrated applications. Solutions are desirable to streamline these operations and the others described above.
SUMMARY OF THE INVENTION
[0013] The disclosure describes methods and systems relating to the access of externally hosted applications, such as software as a service (SaaS) applications (Apps), via a service accessed from a single user interface or portal. This service may provide a unified login experience to a number of external applications, such that the credentials required to access the external applications do not need to be known to the user. Embodiments of this service can provide a set of features, such as authentication, authorization, audit, delegated credentials, messaging, storage, data access, and alerts (Core Services), such that a set of services or Apps may be available to be interacted with, to an end user; an organization that the user is a member of; or other Apps to provide coordinated functionality to the user and organization without requiring pre-arranged integration between the Apps. This set of Core Services, individually or in combination, can allow one or more Apps to provide functionality beyond what is available from an individual App operating in a one-to-one relationship with the end user or end user's organization.
[0014] In some configurations, the systems and methods may allow for users to access the external applications by having access and credentials to the service itself and not the external applications. The systems and methods may allow multiple users access to external applications and shared pages without having to share the login credentials, such as a password. Users may also be able to view messages and alerts from all external applications in a consolidated alert or message box. Users and administrators may also be able to request or grant access to external applications without sharing credentials and create/modify/delete users and user access to applications individually or via a bulk process. These features and functions are discussed in more detail below.
[0015] In some configurations according to the present disclosure a method providing sign-on to applications may be provided. The method may comprise accepting a user login from a user to a system and accepting an application access request for at least one application. The method may also include providing an authenticated session to the application.
[0016] Other configurations provide a single sign-on system operable on a server, accessible by a network. The system comprises a server component for allowing single sign-on to multiple applications, the server component capable of storing user information, application login credentials and user application permission information. The server also includes a client interface which interacts with the server component, the client interface capable of receiving user information and requests for user access to at least an application. Furthermore, the server component is capable of creating an authenticated session to the application and providing the session to a user.
[0017] Yet other configurations include a computer program product, comprising a non-transitory computer-readable medium. The computer program product comprises code for accepting a user login from a user to a system and code for accepting an application access request for an at least one application. The computer program product may also include code for providing an authenticated session to the application.
[0018] A better understanding of the features and advantages of the present embodiments will be obtained by reference to the following detailed description of the invention and accompanying drawings, which set forth illustrative embodiments in which the principles of the invention are utilized.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The accompanying drawings are included to provide a further understanding of the present invention, and are incorporated in and constitute a part of this specification.
[0020] FIG. 1 illustrates an exemplary system for allowing sign-on for multiple applications according to one embodiment of the present disclosure.
[0021] FIG. 2 illustrates another embodiment of a system for allowing sign-on for multiple software as a service (SaaS) applications according to one embodiment of the present disclosure.
[0022] FIG. 3 illustrates a flowchart for performing a method of sign-on for multiple software as a service (SaaS) applications according to one embodiment of the present disclosure.
[0023] FIG. 4 illustrates a process for managing user accounts en masse according to one embodiment of the present disclosure.
[0024] FIG. 5 illustrates a system for creating an integrated message inbox for a user of multiple external services according to one embodiment of the present disclosure.
[0025] FIG. 6 illustrates another representation of an exemplary system for providing single sign-on to multiple applications according to one embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
[0026] In the description that follows, numerous details are set forth in order to provide a thorough understanding of the invention. It will be appreciated by those skilled in the art that variations of these specific details are possible while still achieving the results of the invention. Well-known elements and processing steps are generally not described in detail in order to avoid unnecessarily obscuring the description of the invention.
[0027] Embodiments of the invention are described herein with reference to illustrations that are schematic illustrations of embodiments of the invention. As such, the actual size, components and features can be different, and variations from the components of the illustrations as a result, for example, of manufacturing techniques and/or tolerances and system configurations are expected. Embodiments of the invention should not be construed as limited to the particular components illustrated herein, but are to include deviations in system architecture and improvements. The regions, sections and components illustrated in the figures are schematic in nature and their devices and shapes are not intended to illustrate the precise shape of a feature of a device or device itself and are not intended to limit the scope of the invention. Furthermore, components described as being connected or connections may not be direct. Intervening components or connections may exist. Also, components may be shown as one unit, but may instead be a collection of components or units.
[0028] In the drawings accompanying the description that follows, reference numerals and legends (labels, text descriptions) may be used to identify elements. If legends are provided, they are intended merely as an aid to the reader, and should not in any way be interpreted as limiting.
[0029] As the use of software as a service (SaaS) applications becomes more widely used by individuals and organizations alike, it is desirable to streamline and improve the use of these applications. The present disclosure discusses systems and methods to do so, including, for example, providing a single sign-on experience to a user for multiple applications, managing the users and user access to multiple applications whether one or many users use the same application, and notifying users of messages and alerts from these applications on a unified screen.
[0030] FIG. 1 illustrates one configuration of a system according to the present disclosure for allowing sign-on for multiple applications. In some configurations, this sign-on may function to an end user as a single sign-on to multiple applications. Also, the sign-on process may be transparent to the end user, occurring in the background or unnoticed by a user. The applications accessed may be traditional applications, remotely hosted applications, or applications referred to as software as a service (SaaS) applications. The system over which communication is held may be any network, such as an Internet or private network connected system that includes a client-side UI and/or component, and various server-side components. A user can utilize this system by accessing an interface to allow single sign-on to multiple external SaaS applications (“external Apps”). The system may be accessed via an internet-based, browser-based or app-based interface.
[0031] In this configuration of the system, the service 103 manages the user sign-on process, such that a user signs in the service and then proceeds to access the applications available to the user through an interface of the service. More specifically, by signing into the service 103 , the user is able to create authenticated sessions with all pre-configured external Apps without having to supply credentials (e.g., username and password) for the external App. The user does not need to know and may never have even seen the password or other credentials for the account they're logging into in the external App.
[0032] The system generally incorporates three components, a client side component 101 , a server side component 103 , and access to third-party external applications 104 . In FIG. 1 , the process starts in the top left, with a user accessing the Client Application 101 , using it to sign onto the service 103 . The client application 101 may be hosted in the same location as the server side component 103 or elsewhere. The client application 101 allows the user to view the available external Apps that the user may access. These Apps include those that the user and/or an administrator have previously configured for the user to access. The user selects the external App that the user wishes to use, and this selection initiates a request to the server side component, the service 103 . This request may be initiated directly or in other embodiments it may be initiated through a service agent/plugin 102 , if installed (if not installed, the user is guided through installation). Though the term “plugin” is used here, in other embodiments this function might be performed by any other component on the user or client side, such as directly by the browser, extensions, software agents, add-ons, snap-ins, scriptlets, a stand-alone application or similar technologies.
[0033] A request then passes from the client application 101 , or plugin 102 , to the server side component or service 103 , where various operations and checks are performed, and the previously stored login credentials for the user for the desired external App are retrieved. Thereby, removing any need for the user to directly provide credentials to initiate an authenticated session with the external App 104 .
[0034] Most external Apps 104 utilize session authentication methods that can be initiated via server-to-server (“server-side”) logins, e.g. passing the user credentials directly from the service 103 to the external App systems 104 , and receiving useable session credentials in return. However, some external Apps 104 employ additional levels of security in their session credentials, such as the IP address from which the session was initiated, which in turn requires that the login procedure be conducted from the client. If the external App 104 allows server-side logins, a login request is sent from the service 103 , passing the user's login credentials to the external App's servers 104 . The external App 104 replies with information, which the service 103 sends back to the client 101 or plugin 102 . This information, which may be a session credential, session/cookie or other necessary information to conduct an authenticated session in the external App, might be a set of standard HTTP cookies. In other embodiments of the invention, this information could be a session GUID or similar token, or any other manner of tracking identifiers typically transferred between systems to indicate an authenticated session.
[0035] If the external App 104 does not allow server-side logins, the service 103 passes an encrypted or digitally signed script, including the user's login credentials, back to the client 101 or plugin 102 . The client 101 or plugin 102 then issues a login request to the external App 104 , and captures the session information response.
[0036] In both cases, the plugin 102 , when used, then passes the session information to the client application 101 , and the user, via the client application 101 , is forwarded to their desired external App 104 , where the user arrives already logged in, without being required to enter login information or credentials (for example, username and password) to start their authenticated session. In other embodiments, the user or administrator may have the option of allowing the user to directly login to selected or all Apps by providing a username and password, rather than having the system handle the login process.
[0037] FIG. 2 is a more detailed illustration of another embodiment of a system 200 for allowing sign-on for multiple software as a service (SaaS) applications in accordance with the present disclosure. The system 200 is an Internet or private network connected system that includes a client-side UI and/or component, and various server-side components. Server side components may include an intelligent external App API layer, User-App Credentials and Logging databases. Additional components may also be incorporated. A user will utilize this system by accessing the Internet-based or app-based interface as a single sign-in portal via a public or private network, such as the Internet or corporate network.
[0038] Starting from the top left of FIG. 2 , a user interface 201 to the system or service 205 is provided as an Internet or private network-based front-end portal 202 . The portal may be hosted remotely or locally. The primary component of the portal 202 includes a dashboard that acts as a container for all other user interface elements or widgets 203 for initiated functions of the system 205 . In other embodiments of the invention, this front-end portal could be replaced with an application or “app”. The widgets 203 are graphical elements that represent links to external applications (Apps) 210 that the user of the system has selected or that have been selected for the user by an administrator from the user's organization. Additionally, the widgets 203 also contain links and/or shortcuts to other functions of the system 205 available through the portal 202 . In other configurations, the system 205 may include additional functionality that is exposed through the portal 202 such as enhanced chat features. These enhanced chat features may offer standard inter-user and group messaging, but may also offer the ability to share App access, synchronize App views, and in other embodiments may allow a wide range of real-time commands to be executed on the client to expand functionality of the portal 202 or the external Apps 210 .
[0039] In some embodiments, the graphic elements or widgets 203 are not confined to a stationary location, but can be moved and re-ordered within the dashboard of the portal 202 by the user of the system 205 . To this end, the dashboard of the portal 202 is dynamic in nature, and can be customized.
[0040] As seen in FIG. 2 , the single sign-on function starts when a user requests a session with the external application (App) of their choosing from those available in their dashboard 202 , by selecting (clicking, tapping, etc.) on the corresponding widget/logo 203 . A “session” herein indicates any interaction between the user and a service or application. An “authenticated session” indicates an interaction wherein the identity of the user has been asserted and, in some configurations, verified.
[0041] This selection initiates a request to the plugin 204 , if installed (if not installed, in some embodiments the user is prompted to install the plugin). The term “plugin” is used here, but in other embodiments of the invention this function might be performed by any other component such as extensions, software agents, add-ons, snap-ins, scriptlets, or similar technologies.
[0042] A request then passes from the plugin 204 to the services 206 , where a database, such as the User-App Login DB 208 , is checked, and corresponding login credentials for the user are retrieved. The User-App Login DB 208 may be hosted as part of the services 206 , or may be an externally-hosted database or similar system. These login credentials might be, for example, username and password, a PIN, a public key or certificate, biometric information, or any other type of authentication information.
[0043] In some embodiments, all external connections to and from the system 205 are performed over a network, such as the public Internet or private networks.
[0044] If the external App 210 allows server-side logins, a login request is sent from the services 206 , passing the user's login credentials to the external App's servers 210 . This login request may occur via submitting the external App's 210 login from inside a virtual browser 207 , or other user client emulator, or via an API, if available. The external App 210 replies with session/cookie information, which the services 206 send back to plugin 204 . This session/cookie information might be standard HTTP cookies, or in other embodiments of the invention, it could be a session GUID or similar token, or any other manner of tracking identifiers typically transferred between systems to indicate an authenticated session. The service 206 logs this access in the Access Log database 209 for later auditing.
[0045] If the external App 210 does not allow server-side logins, the services 206 pass an encrypted script, including the user's login credentials, back to the plugin 204 . The plugin 204 then issues a login request to the external App 210 , and captures the session/cookie information response.
[0046] In both cases, the plugin 204 then passes the session/cookie information to the user's browser 201 , and the user's browser 201 is forwarded to their desired App 210 , where the user arrives already logged in, without being required to enter login information to start their session. The plugin 204 can also log this access in the Access Log database 209 via the services 205 , for later auditing.
[0047] In some configurations, the system 205 includes a secondary auditing function which may be very beneficial to the user of the service with respect to business compliance and governance. The data contained within this Access Log database 209 can be queried and reported in various formats. This data can be used to create reports for testing evidence for audits such as SOX, GLB, PCI, HIPAA, and other industry-specific data and information security compliance regulations. Such data can also be used to produce activity reports for a single user or a group of users across all managed and monitored SaaS applications.
[0048] FIG. 3 illustrates a flowchart for performing a method of sign-on for multiple software as a service (SaaS) applications in accordance with an embodiment of the invention. This drawing is a walk-through of embodiments of systems according to the present disclosure such as the system described in FIG. 2 .
[0049] As seen in FIG. 3 , the single sign-on function starts at step 300 when a user requests a session with the external application (App) of their choosing. This request may be initiated by choosing from the Apps available in their dashboard 202 , by clicking on the corresponding widget/logo 203 . At step 301 , this request is then passed from the user's browser, optionally through the plugin 204 , and on to the service 205 .
[0050] In step 302 , the request is received by the service 205 , where the service 205 verifies that the user is validly signed in to the service 205 . If not, this request process ends at step 303 , where the user is asked to sign in to the service 205 . If the user is properly signed in to the service 205 , the user's sign-in credentials with the desired App are retrieved from a database, such as the User-App DB 208 , in step 304 . If no valid credentials are found for the user for the desired external App 210 in the User-App DB 208 , this request process ends at step 303 , where the user is alerted to the missing/invalid credentials.
[0051] If valid sign-in credentials are found in step 304 , or, in some embodiments, in steps 304 and 305 , the service 205 next determines if the external App 210 requires client-side login, in step 306 .
[0052] If in step 306 it is determined the external App 210 requires client-side login, a login script is generated by the services 205 in step 307 . In some configurations it may be desirable to have sensitive data in the script encrypted, and the entire script cryptographically signed, to detect and prevent tampering. This script is then returned to the plugin 204 , where the script is executed, via a connection to the external App 210 , in step 308 .
[0053] If in step 306 it is determined that the external App 210 does not require a client-side login, in step 309 the services 205 next evaluate if the App requires a special API to execute the login. This evaluation may take place using any method which would allow the system to recognize whether an API is required, or the requirement may be saved or designated by the service such that an evaluation is not required at each access. In some configurations, this evaluation is based on a hierarchy of access methods. For example, if a standards-based SSO API, such as but not limited to SAML or OpenID, is available from external App 210 , it is utilized. The system 205 may elect to use a configured access token (for example, API key or OAuth) in requests not involving authentication. If the external App does require a special API call, in step 310 the service constructs and executes the required API call.
[0054] If in step 309 it is determined that no special API is required, in step 311 a “virtual browser” or other similar emulator is started by the service 205 . In step 312 , the virtual browser loads the external App's login form, supplies the user's credentials, and submits the form.
[0055] Successful execution of steps 308 , 310 , and 312 all lead to step 313 , where the session/cookie response of the external App 210 to the various potential methods of login requests is captured, and transmitted to the plugin 204 , or directly to the user if a plugin is not in use, if not already there.
[0056] In step 314 , the plugin 204 passes the session/cookie information to the user's browser 201 , and in step 315 the browser is forwarded to the desired App's URL. The process ends at step 316 , as the user arrives at the external App 210 as a logged in user, without being required to enter login information to start their session.
[0057] As described previously, it can also be desirable to be able to manage user accounts for various Apps through the service. Such a process may allow an administrator or user to detect existing users and associated accounts and map them to each other to give users access to these accounts. The process may also allow for deleting, clearing, and quick management of other accounts and account access. The process may also allow for quick bulk creation of new/existing user access to new/existing Apps. FIG. 4 illustrates one configuration of a process according to one embodiment of the present disclosure for creating user accounts en masse in the service 205 or an external App 210 , such that users can then access these user accounts from their client application, based on existing user accounts in either. This process may be useful in organizations with many users, using many Apps, saving Administrators and users time when starting to use the service, or when rolling out new external Apps to the organization. By starting with the list of users already existing in one (or multiple) systems, accounts can quickly be created for all required users in any new Apps. This process may also be useful in identifying accounts that should be removed or disabled from one or more of the systems.
[0058] In step 405 , the lists of user accounts, along with basic account information (examples: email address, first name, last name) for the organization are gathered from the service and from the external App. The external App referenced here might be an SaaS system, an LDAP service or similar directory system containing accounts for some or all members of the organization. This process may be automated, via APIs, or the administrator may supply a text file with the account information. The basic account information may be for members of the organization or third parties that the organization may want to provide access or accounts for to the system.
[0059] In step 410 , the lists are compared, searching for exact matches of the information fields provided (for example, based on email address associated with the user account).
[0060] In step 415 , the lists are compared, searching for “fuzzy” or near matches of the information fields being compared (for example, based on first and last name associated with the user account). In some configurations, steps 410 and 415 may be combined, whereas in other configurations only one or both of the steps may exist.
[0061] In step 420 , the lists are compared, to find accounts in either system that were not matched in steps 410 or 415 .
[0062] In step 425 , the results of the mapping process (steps 410 - 420 ) are presented to the user/Administrator, who is allowed to make corrections (for example: adding, removing or modifying account mappings, or excluding new accounts from being created). In some configurations, this step may be omitted proceeding directly to step 430 .
[0063] In step 430 , accounts are created/removed/modified in the service 205 or the external App 210 as needed. The creation/removal/modification of accounts may be completely automated, via, for example, APIs, or may enlist user involvement. After the accounts have been created/removed/modified, all account mappings are saved in the User-App Login DB 208 . These saved account mappings are later used to associate the user account in the service 205 with the corresponding account in the external App(s) 210 , and are referenced, for example, when a user requests a session with an external App 210 , or when the service needs to check an external App 210 for new messages for the user.
[0064] In some configurations, the service may provide users with a streamlined view of messages, alerts, or notifications from all or a subset of the Apps they can access through the service. FIG. 5 illustrates a system 500 for creating an integrated message inbox for a user of multiple external services, in accordance with an embodiment of the invention. The “messages” might be e-mail-like correspondence, system status updates or alerts, social media updates, or any other type of message that might be generated by the external Apps 210 . This system aggregates the messages generated by the various external Apps 210 for the user in one central repository. In other configurations, the messages or alerts may be placed in any number of separate inboxes rather a single inbox. This central repository may also contain system alerts and e-mail-like correspondence from the service 205 .
[0065] The integrated message box system flow starts when the Message Retrieval Service 501 executes. This process may start automatically (scheduled, periodic, etc.), or on user (for example, end user or administrator) request.
[0066] The Message Retrieval Service 501 may execute for all users, a group of users, or a single user listed in a database, such as the User-App Login DB 505 . The Message Retrieval Service iterates over the following process for all or a subset of the external Apps 210 associated with the user accounts for which it is attempting to retrieve messages:
[0067] The Message Retrieval Service 501 retrieves the necessary Login Credentials for the account(s) for which it will be retrieving messages from the User-App Login DB 505 . It then passes a request to the App Interaction Layer 502 , where the system decides the appropriate method for connecting to the external App 507 . n in question. The App Interaction Layer may connect to the external App 507 . n via a Virtual Browser 503 , via an API 504 , or any other appropriate connection method.
[0068] In either case, the user account's login credentials are sent to the external App 507 . n , and any new messages for the user are requested.
[0069] Any new messages received from the external App 507 . n are saved into the App Message DB 506 , and will be available for the user when they access the portal 202 . In some configurations, while the user is using the portal 202 , these messages may also be updated in real time through use of available real time update techniques or technologies (for example, web sockets, long-polling or other persistent or semi-persistent network connections). In yet other configurations, these techniques may also be used to update, in real time, areas of the interface unrelated to messaging, such as the list of available Apps.
[0070] FIG. 6 depicts an illustration of a system which provides single sign-on to an application. The system 600 incorporates a user interface 604 , a user and permissions database 606 , and the functionality which allows the creation of application authentication 608 . As described previously, a manager, company, or managing user 612 may access the system 600 and provide settings or information to provide access to users 602 for applications 610 . The user 602 may be a member or employee of the company the manager 612 belongs to or an outside party or other system user that has been authorized access to an app 610 by a manager or other person 612 authorized to provide access or access credentials.
[0071] A manager 612 may access the system 600 via a user interface 604 . From the user interface 604 the manager 612 may enter credentials for access to 3rd party applications 610 into the user and permissions database 606 . These credentials may be for the manager 612 themselves or for other system users 602 . These may be existing users or newly created users. The manager 612 may also manage and maintain lists of users 602 and access permissions.
[0072] A user 602 may access the system 600 via a user interface 604 , using a single log on to the system. Once logged into the system 600 a user 602 would be presented with an interface which displays a listing of 3 rd party applications or apps that the user may access. The listing may be of applications that the user already has been given permissions to, without further input of log in credentials, but may also include other applications the user may access if the user can provide access credentials.
[0073] After a user chooses an application 610 to access, the system 600 determines whether the user has access to the chosen application. Next the system 600 executes the appropriate app authentication process 608 and passes the authenticated session to the user 602 . As described previously, this authentication may be done server to server between the system 600 and the 3 rd party app 610 , such that the session is then passed to the user 602 , or the information may be passed to a plugin 614 on the user's system 602 , such that encrypted information may be passed to the plugin 614 from the system 600 to create or initiate the authenticated session for the app 610 , without the user ever inputting or having known the log in credentials for the app 610 . Thereby, the user can access several 3 rd party apps by logging in to the system with a single log in and not providing any further log in credentials.
[0074] While the foregoing written description of the invention enables one of ordinary skill to create and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention. | The disclosure describes systems, methods and devices relating to a sign-on and management hub or service for users of multiple internal, external or Software-as-a-Service (SaaS) software applications (Apps), with options for centralized management and sharing of accounts without needing to provide login credentials to individual users. | 7 |
PRIORITY CLAIM AND INCORPORATION BY REFERENCE
[0001] This application is a continuation of U.S. app. Ser. No. 14/634,598 filed Feb. 27, 2015 which claims the benefit of 62/085,633 filed Nov. 30, 2014 and which is a continuation-in-part of U.S. app. Ser. No. 14/061,601 filed Oct. 23, 2013, now U.S. Pat. No. 9,027,654, which is 1) a divisional of U.S. app. Ser. No. 13/089,312 filed Apr. 19, 2011, now U.S. Pat. No. 8,955,601 and 2) a continuation-in-part of U.S. app. Ser. No. 12/766,141 filed Apr. 23, 2010, now U.S. Pat. No. 8,545,190. All the above applications are now incorporated herein by reference, in their entireties and for all purposes.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a valve for use in a downhole production string. In particular, the valve includes a pump rotor passage.
Discussion of the Related Art
[0003] Downhole production equipment is located in hard to reach places and therefore presents significant challenges to operators during both normal and abnormal conditions.
[0004] Downhole production strings may include production facilities such as a valve between a rod driven pump and pipe through which a fluid is transported or produced. For various reasons a valve, pump, and/or pipe may need to be installed in or removed from a downhole location. For example, installation and recovery of production string parts may be for one or more of normal production set up and take down, maintenance, repair, and replacement.
[0005] Relocating production string parts to or from downhole stations is typically a time consuming process involving labor, equipment, and materials. With traditional production string parts, the sequence of steps required to assemble/disassemble and/or deploy/recover downhole production string parts frequently delays relocation operations.
[0006] To the extent that relocation delays are reduced, less production time is lost and production or surfacing of the desired resource, such as a liquid hydrocarbon from a subterranean reservoir, is enhanced.
SUMMARY OF THE INVENTION
[0007] The present invention provides a downhole production string valve that includes a pump rotor passage.
[0008] In an embodiment, a valve for use in a downhole production string comprises: a body, a shuttle slidably inserted in the body, and a bobbin for mating with the shuttle; the valve body and shuttle provide a pump rotor passageway; and, the passageway is for receiving a rotatable rod therethrough and the bobbin is for slidably contacting the rod; wherein during normal operation of the production string a pump driven by the rod pumps fluid through the passageway and during a pump rotor removal operation a rotor of the pump is passable through the passageway.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention is described with reference to the accompanying figures. The figures listed below, incorporated herein and forming part of the specification, illustrate the invention and, together with the description, further serve to explain its principles enabling a person skilled in the relevant art to make and use the invention.
[0010] FIG. 1 is a first schematic diagram of a downhole production string including a valve.
[0011] FIG. 2A is a second schematic diagram of a downhole production string including a valve.
[0012] FIG. 2B is a cross-sectional view A-A of FIG. 2A .
[0013] FIG. 3A is a third schematic diagram of a downhole production string including a valve with a pump rotor passage.
[0014] FIG. 3B is a cross sectional view through the valve illustrating pump rotor clearance.
[0015] FIGS. 4A-H show a diverter valve that provides a pump rotor passageway in a rod driven downhole production system.
[0016] FIGS. 5A-B are flowcharts illustrating use of the valve of FIG. 4A and its pump rotor passageway.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] The disclosure provided in the following pages describes examples of some embodiments of the invention. The designs, figures, and description are non-limiting examples of certain embodiments of the invention. For example, other embodiments of the disclosed device may or may not include the features described herein. Moreover, disclosed advantages and benefits may apply to only certain embodiments of the invention and should not be used to limit the disclosed invention.
[0018] To the extent parts, components and functions of the described invention provide for exchange fluids, the suggested interconnections and couplings may be direct or indirect unless explicitly described as being limited to one or the other. Notably, indirectly connected parts, components and functions may have interposed devices and/or functions known to persons of ordinary skill in the art.
[0019] FIG. 1 shows an embodiment of the invention 100 in the form of a schematic diagram. A spill or bypass valve 108 is interconnected with a pump 104 via a pump outlet 106 . The pump includes a pump inlet 102 and the valve includes a valve outlet 110 and a valve spill port 112 . In various embodiments, the inlets, outlets and ports are one or more of a fitting, flange, pipe, or similar fluid conveyance.
[0020] FIG. 2A shows a section of a typical downhole production string 200 A. The production string includes the bypass valve 108 interposed between the pump 104 and an upper tubing string 204 . In some embodiments, a casing 208 surrounds one or more of the tubing string, valve, and pump. Here, an annulus 206 is formed between the tubing string and the casing. A production flow is indicated by an arrow 102 while a backflow is indicated by an arrow 202 . In various embodiments, the bypass valve incorporates a spill port and in various embodiments the valve is operable to isolate backflows from one or more of the valve, portions of the valve, and the pump.
[0021] Some embodiments of the production string include an extended tubular element 203 coupled with the upper tubing string 204 . For example, the extended tubular element may be a part of the valve or may be separate from the valve. In an embodiment, the extended tubular element is a valve body portion. The production may use a pump such as a rod driven pump with a pump drive rod 250 passing through the tubing string and interconnecting with the pump (pump interconnection is not shown).
[0022] FIG. 2B shows a cross-section A-A through the production string of FIG. 2A . Clearance(s) 260 between the rod 250 and the extended tubular element 203 and clearance(s) 262 between the extended tubular element and the casing 208 are shown. In particular, clearance(s) between the rod and the extended tubular element may be chosen to guide the rod and as such may be less than similar clearance(s) associated with the upper tubing string. In some embodiments, guards or ribs mounted within the extended tubular element or to the rod provide stand-offs to guide the rod.
[0023] FIGS. 3A-B shows a schematic view of an end portion of a downhole production string assembly 300 A-B. The assembly includes a valve 108 interposed between a rod 250 driven pump 104 and a section of production tubing 204 . In some embodiments, a diverter valve with a rod mounted bobbin is used and in some embodiments, a progressive cavity pump is used.
[0024] The pump 104 includes a pump rotor 276 having an outer periphery 284 and an outer diameter d 62 that may engage with a pump stator such as a surrounding pump stator 274 . Rotation of the pump rotor causes a fluid at the pump inlet 290 to be drawn into the pump and discharged into the valve 108 .
[0025] During fluid production operation, the rod 250 turns the pump rotor 276 such that a fluid is drawn into the pump intake 290 , moves through the pump 104 , through the valve 108 , out of the valve 292 , and into the production tubing 282 .
[0026] The valve 108 includes a bore or pump rotor passage 280 having a minimum diameter d 61 designed with a valve to rotor clearance c 61 that allows for passage of the pump rotor 276 having a diameter d 62 to pass through the valve. As used herein, bore refers to a passageway formed by any suitable method known to skilled artisans.
[0027] During operations requiring pump rotor 276 relocation, the rod 250 which is coupled to the pump rotor is used to move the rotor through the production string components. For example, during installation, the rotor is lowered on the rod through the production tubing 204 , through the valve rotor passage 280 , and into the pump stator 274 .
[0028] FIGS. 4A-H show valve embodiments that include a pump rotor passage 400 A-H.
[0029] FIG. 4A shows diverter valve with a bobbin incorporated in a downhole production string assembly with a rod driven pump. FIG. 4B shows an enlarged middle portion of the valve of FIG. A in the bobbin up configuration. FIG. 4C shows the enlarged middle portion of the valve of FIG. A when the bobbin is down 400 C. As seen in the figures, a valve body 402 includes an upper body or stand-off 404 , a middle body 405 , and a lower body 406 .
[0030] In the embodiment of FIG. 4A , a valve 401 has a valve body 402 that extends between upper 403 and lower 407 adapters. In various embodiments, valve sizes include but are not limited to 2⅜ inch, 2⅞ inch, and 3½ inch. The lower adapter is coupled with a rod driven pump 445 , such as a progressive cavity pump, having a pump rotor 256 with a maximum outer diameter d 72 that is inserted in a pump stator 254 . In some embodiments, the pump is directly connected with the valve or a lower adapter and, in some embodiments, an optional pump connector spool 447 is interposed between the pump and the lower adapter (as shown).
[0031] The upper body includes a first through hole 469 . In some embodiments, the first through hole passes through an outlet chamber 465 of an upper adapter 403 . And, in some embodiments, an inner surface of the adapter 467 is threaded. As used herein, the phrase through hole indicates a thru-hole passage. And, as persons of ordinary skill in the art will recognize, embodiments may have a through hole with a constant cross-section or a through hole of varying shape and/or cross-section as shown here. Embodiments of the adapter block a bobbin 411 from leaving the upper body 404 . In an embodiment, the bobbin is in slidable contact with a polished rod portion 419 , for example to reduce bobbin-rod friction to bobbin sliding.
[0032] The middle body includes a second through hole 471 . In various embodiments, the second through hole provides or adjoins a shuttle chamber 461 and fluidly couples the valve outlet chamber 465 with a valve inlet chamber 464 . The lower body includes a third through hole 473 . In various embodiments, the third through hole passes through the inlet chamber 464 . As used herein, the term couple refers to a connection that is either of a direct connection or an indirect connection that may further include interposed components.
[0033] Within the lower body 406 , a spring shoulder such as an annular spring shoulder 444 for supporting a charge spring 408 projects inwardly from a first inner bore of the lower body 472 . In some embodiments, the shoulder extends between the first inner bore of the lower body and a cylindrical spring guide 442 .
[0034] And, in some embodiments, the shoulder 444 and the spring guide 442 are portions of a lower adapter 407 forming at least part of the lower body 406 . In various embodiments, an upper end of the adapter 474 has a reduced outer diameter 476 such that the spring shoulder is formed where the diameter is reduced and the spring guide is formed along the length of the reduced diameter portion of the adapter. As shown, portions of the charge spring 408 are located in an annular pocket 463 between the first inner bore of the lower body 472 and the spring guide. The adapter and lower body may be integral or fitted together as by a threaded connection 446 or another connection known to a skilled artisan.
[0035] In some embodiments, a spring guide port 456 provides a means for flushing the annular spring pocket 463 . As seen, the port extends between the lower chamber 464 and the annular pocket 463 . Action of the charge spring 408 and/or pressure differentials between the pocket and the lower chamber provide a flushing action operative to remove solids such as sand that may otherwise tend to accumulate in the annular pocket.
[0036] Within the middle body 405 , a middle body bore 438 is for receiving a valve shuttle 410 . The charge spring 408 is for urging the shuttle toward the valve outlet end 499 . This shuttle urging may be via direct or indirect charge spring contact. For example, embodiments utilize direct contact between a shuttle lower end 421 and an upper end of the charge spring 478 . Other embodiments utilize indirect contact such as via an annular transition ring 423 having an upper face 493 contacting the shuttle carrier lower end and a lower face 425 contacting a charge spring upper end (as shown).
[0037] Near a lower end of the upper body 475 , an inwardly projecting nose 430 includes a stationery seat 432 for engaging a closure 414 encircling a shuttle upper end 413 . In various embodiments, the shuttle has a tapered upper end 417 and the closure is part of or extends from this taper. In various embodiments the seat and closure are configured to meet along a line forming an angle θ<90 degrees with respect to a valve centerline y-y. Absent greater opposing forces, the charge spring 408 moves the shuttle 410 until the shuttle closure 414 is stopped against the stationery seat 432 to form a first seal 431 .
[0038] The rod driven valve includes a central, rotatable, pump driving rod. The rod section shown is a lower rod section 409 with a central axis about centered on the valve centerline y-y. Not shown is this or another rod section's interface with a pump or an upper rod portion that is coupled to a rotating drive means.
[0039] The lower pump driving rod 409 passes through the valve body 402 . In particular the rod passes through the first through hole 469 , through the shuttle bore 452 , and through the third through hole 473 . Like the valve of FIG. 3A , the valve of FIG. 4A has a part dragged by fluid flow, the bobbin 411 . The bobbin is slidably mounted on the rod above the shuttle as shown in FIG. 4A . The bobbin has a mounting hole for receiving the rod. Bobbin shapes include fluid-dynamic shapes suitable for utilizing drag forces operable to lift the bobbin when there is sufficient forward flow 488 . For example, the bobbin may be shaped with substantially conical ends (as shown).
[0040] In an embodiment, the bobbin 411 includes a bobbin body 420 with a through hole 418 and a peripheral groove 412 defining a plane about perpendicular to the valve y-y axis. The groove is for receiving a bobbin ring 413 and the bobbin ring is for sealing a shuttle mouth 461 . In various embodiments, the bobbin body is made from polymers such as plastics and from metals such as stainless steel. And, in various embodiments, the bobbin ring is made from polymers such as plastics and from metals such as stainless steel.
[0041] In some embodiments, the bobbin body 420 and ring 413 are integral and in some embodiments the bobbin has a bobbin hole insert (not shown) that is made from a material that differs from that of the bobbin body, for example, a metallic insert fitted into an outer plastic body. And, in an embodiment, the bobbin body is injection molded and a metallic bobbin ring is included in the mold during the injection molding process.
[0042] As further explained below, the bobbin 411 moves along the rod 409 in response to flow through the valve, rising above the shuttle 410 when there is sufficient forward flow 488 , and falling to mate with the shuttle when there is insufficient forward flow and when there is reverse flow 489 . See also the perspective cutaway view of a similar valve 400 H of FIG. 4H .
[0043] FIGS. 4D-E show the shuttle in a compressed spring position 400 D-E. Unlike FIGS. 4A and 4B showing a normal forward flow 488 through the valve 401 with the shuttle stationery seat 432 and closure 414 mated, FIGS. 4D-E show the shuttle 410 separated from the closure 414 during a reverse flow 489 , the charge spring 408 being compressed by movement of the shuttle toward the valve inlet end 498 . Notably, one or more sliding seals about the shuttle provide a sliding seal 435 between the shuttle 410 and a middle body bore mated with the shuttle such as the middle body bore 438 .
[0044] When there is sufficient forward flow 488 through the valve 400 B, flow through the shuttle bore 452 lifts the bobbin 411 above the shuttle 410 and the charge spring 408 holds the shuttle against the valve body protruding nose 430 . With the bobbin lifted above the shuttle, flow passes freely through the shuttle bore and into the valve outlet chamber 465 .
[0045] FIG. 4F shows a valve embodiment similar to the valve of FIG. 4A with an upper body 404 having a length l 1 . Here, an upper adapter 403 is configured, as by guards, spokes, annular obstructions or the like, to stop the bobbin from rising beyond the upper adapter. In various applications, a suitable length l 1 may depend upon factors such as fluid viscosity, bobbin geometry, fluid flow rate ranges, and spacing between the bobbin and surrounding structures. In some embodiments, length l 1 for 4 and 6 inch valve sizes is in the range of about 2 to 10 feet. And, in some embodiments, length l 1 is in the range of about 4 to 20 times the valve size. Skilled artisans may utilize knowledge of the application and its constraints such as fluid properties to select suitable geometric variables including length l 1 .
[0046] In an embodiment, the upper body 404 or an extension thereof functions as a flow tube having an internal diameter (FTID) that is greater than the internal diameter of downstream production tubing 204 (PTID). Flow tube lengths may be 2-10 feet in some embodiments, 4-8 feet in some embodiments, and about 6 feet in some embodiments.
[0047] For a given rate of fluid production, the flow tube feature provides for lower fluid velocity in the flow tube as compared with production tubing fluid velocity and for managing the operation and travel of the bobbin 411 . For example, as the ratio FTID/PTID increases, the likelihood of bobbin travel into the production tubing is reduced. And, for example, as the magnitude of FTID increases, the pump flowrate required to suspend the bobbin above the shuttle 410 increases. In various embodiments, the ratio FTID/PTID is in the range of 1.05 to 1.5 and in some embodiments, the ratio FTID/PDID is in the range of 1.1 to 1.3. As skilled artisans will appreciate, choosing this ratio depends, inter alfa, on fluid properties and transport conditions.
[0048] Referring to FIG. 4C (see detail area 4 BA of FIG. 4B ), the rising shuttle is stopped when the shuttle closure 414 mates with the stationery seat 432 forming the body-shuttle seal 431 . Forces acting on the bobbin 411 include drag forces due to flow through the shuttle bore 452 and gravitational forces. In various embodiments, when drag forces are overcome by gravitational forces due to insufficient forward flow, the bobbin falls relative to the shuttle 410 .
[0049] Notably, during an inadequate flow event, the bobbin 411 falls relative to the shuttle 410 (see FIG. 4E and detail area 4 CA of FIG. 4D ), On shuttle contact, the bobbin ring closure 480 comes to rest against a shuttle mouth seat 481 forming a shuttle-bobbin seal 482 and blocking flow through the shuttle. Pressure forces at the valve outlet P 22 act on the blocked shuttle and move it toward the valve inlet 498 , a process that compresses the charge spring 408 . When the bobbin ring closure and shuttle mouth seat are mated, forward flow is substantially limited. In some embodiments, flow is stopped but for leakage such as unintended leakage.
[0050] As seen, to the extent that the fluid head at the valve outlet P 22 results in a fluid head force on the shuttle sufficient to overcome resisting forces including compressing the charge spring 408 , the shuttle 410 moves toward the inlet end of the valve 498 . In various embodiments, a shuttle diameter 437 , approximated in some embodiments as a middle body bore diameter 439 , provides an estimate of the area acted on by the fluid head and thus the fluid head force. Skilled artisans will adjust valve performance by determining valve variables including a spring constant “k” (F=k*x) of the charge spring to adapt the valve for particular applications.
[0051] Turning now to the spill port 428 , it is seen that forward flow 488 and the body-shuttle seal 431 associated with forward flow enable blocking of the spill port 428 . For example, the spill port may be blocked by forming an isolation chamber and/or by isolating or sealing the port 493 . When the spill port is blocked, flow entering the valve inlet 498 passes through the shuttle through bore 452 , out a shuttle mouth 461 , into the valve outlet chamber 465 , and out of the valve outlet 499 .
[0052] Referring to FIGS. 4D , it is seen that reverse flow 489 and the shuttle-bobbin seal 482 (see also FIG. 4E ) associated with reverse flow enable opening of the spill port 428 as the shuttle 410 moves toward the inlet end of the valve 498 and the upper seal 431 is opened. When the shuttle-bobbin seal is closed, flow through the shuttle is blocked and a sliding shuttle-bore seal 435 blocks flow between the shuttle and the middle body bore 438 . However, the shuttle-body seal 431 is now open and reverse flow entering the valve can pass around the nose 479 and leave the valve 416 via the spill port 428 .
[0053] In some embodiments, reverse flow 489 and/or an adverse pressure gradient (outlet pressure P 22 >inlet pressure P 11 ) move the shuttle 410 toward the valve inlet end 498 by a distance within dimension S 11 . This shuttle stroke unblocks the spill port 428 allowing flow entering the outlet chamber 489 to move through a spill pocket 484 with boundaries including the middle body bore 438 and the shuttle 410 before exiting the valve body 416 via one or more spill ports 428 . And, in some embodiments, the illustrated spill port is one of a plurality of spill ports arranged around a valve body periphery 486 .
[0054] The shuttle 410 of the valve 401 has a periphery 437 that seals, at least in part, against an internal bore of the valve such as the middle body bore 438 . While some embodiments provide a shuttle with a substantially continuous sealing surface (as shown) for providing a sliding seal 435 , various other embodiments provide a discontinuous sealing surface. For example, seals in the form of raised surface portions, rings in groves, snap rings, O-rings, and other suitable sealing parts and assemblies known to skilled artisans may be used.
[0055] FIG. 4G shows a schematic outline of a valve rotor passage 400 G. In particular, the figure illustrates a valve rotor passage for an end portion of a downhole production string assembly such as that of FIG. 4A .
[0056] In the figure, the dashed cylindrical space indicates a passageway 4002 of minimum diameter d 71 extending from the pump 445 and/or pump coupling spool 447 (see FIG. 4A ) and through the valve 401 into the production tubing 204 (See FIG. 2A ). The pump rotor 256 has a maximum outside diameter for passage d 72 such that when the rotor and passageway are coaxially arranged, a clearance c 71 exists between the rotor and the passageway (i.e., d 71 >d 72 ).
[0057] In various embodiments, the clearance c 71 may be referred to as or in connection with drift and may be in the range of 10 to 100 thousandths of an inch and in some embodiments in the range of 20 to 30 thousandths of an inch.
[0058] Some embodiments provide a valve 401 bore that is full drifting of production tubing 204 size. That is, the valve provides a passageway that is at least as large as that of the production tubing such that, for example, a pump rotor 256 able to pass through the production tubing is also able to pass through the valve.
[0059] In an embodiment, a valve portion of the passageway 4002 is defined by i) a valve upper body 404 with a valve upper body bore 429 that is equal to or greater than d 71 , a valve middle body 405 with a valve middle body nose 430 and nose bore 459 that is equal to or greater than d 71 , and a valve lower body 406 with a valve lower body bore that is equal to or greater than d 71 .
[0060] In an embodiment, a valve outlet portion of the passageway 4002 is defined by a valve upper adapter 403 having a valve upper adapter bore 427 that is equal to or greater than d 71 and production tubing 204 having a production tubing bore 229 that is equal to or greater than d 71 .
[0061] In an embodiment, a valve inlet portion of the passageway 4002 is defined by a valve lower adapter 407 having a valve lower adapter bore 449 that is equal to or greater than d 71 and/or a pump connector spool 447 with a pump connector spool bore 457 that is equal to or greater than d 71 .
[0062] FIGS. 5A-B provide flowcharts illustrating exemplary operating scenarios of selected embodiments of the invention 500 A-B.
[0063] FIG. 5A shows a sequence of steps for production facility installation, for example, steps for one of a new installation or an installation following a rework including removal of production tubing.
[0064] First, a stator lowering assembly is assembled and installed as seen in steps 1 - 4 of FIG. 5A .
[0065] In a step numbered 1 , a pump stator (see e.g., 254 , 274 ) and a spool (see e.g., 447 ) are coupled together. In a step numbered 2 , a valve (see e.g., 108 , 401 ) is coupled to the free end of the spool. In a step numbered 3 , production tubing (see e.g., 204 ) is coupled to the free end of the valve. In a step numbered 4 , the stator assembly, stator first, is lowered downhole. As needed, production tubing is added to the production tubing string until sufficient production tubing has been added to reach the desired depth, typically when the pump stator is submersed in reservoir zone that is or will be flooded with liquid. Note that in some embodiments, there is no spool such that the stator and production tubing are coupled together without a spool.
[0066] Second, a rotor lowering assembly is assembled and installed as seen in steps 5 - 8 of FIG. 5A .
[0067] In a step numbered 5 , a pump rotor (see e.g., 256 , 276 ) and a polished portion of pump driving rod (see e.g., 419 ) are coupled together and a bobbin or valve actuator (see e.g., 411 ) is installed on the rod. In a step numbered 6 , the rotor assembly is inserted in the free end of the production tubing (see e.g., 204 ) and lowered downhole. Pump driving rod is added to the drive rod string as needed until the rotor meets and is inserted in the stator (see e.g., 274 ). In a step numbered 7 , the pump rotor is spaced according to the pump manufacturer's specification. In a step numbered 8 , in preparation for the beginning of production of liquids from the reservoir to the surface, the pump drive rod is readied for rotation and then rotated to operate the pump.
[0068] FIG. 5B shows a sequence of steps for production facility equipment removal and installation, for example, steps taken when the pump rotor must be replaced.
[0069] First, the pump rotor is lifted to the surface as seen in steps 1 - 2 of FIG. 5B .
[0070] In a step numbered 1 , the pump drive rod rotation is stopped and preparations are made to pull the rod (see e.g., 409 ) to the surface. In a step numbered 2 , the rod is lifted with the attached rotor (see e.g., 256 , 276 ) until the rotor reaches the surface.
[0071] Second, a rotor lowering assembly is assembled and installed as seen in steps 3 - 6 of FIG. 5B .
[0072] In a step numbered 3 , a new/renewed pump rotor (see e.g., 256 , 276 ) and a polished portion of pump driving rod (see e.g., 419 ) are coupled together and a bobbin or valve actuator (see e.g., 411 ) is installed on the rod. In a step numbered 4 , the rotor assembly is inserted in the free end of the production tubing (see e.g., 204 ) and lowered downhole. Pump driving rod is added to the drive rod string as needed until the rotor meets and is inserted in the stator (see e.g., 274 ). In a step numbered 5 , the pump rotor is spaced according to the pump manufacturer's specification. In a step numbered 6 , in preparation for the beginning of production of liquids from the reservoir to the surface, the pump drive rod is readied for rotation and then rotated to operate the pump.
[0073] The present invention has been disclosed in the form of exemplary embodiments. However, it should not be limited to these embodiments. Rather, the present invention should be limited only by the claims which follow where the terms of the claims are given the meaning a person of ordinary skill in the art would find them to have. | Methods and apparatus for utilizing a valve with a pump rotor passage with a downhole production string, the pump rotor being on a rotatable rod with a bobbin moving along the rod between a position for opening the passage to fluid flow, when the bobbin is not seated on a shuttle seat, and a position for closing the passage to fluid flow, when the bobbin is seated on the shuttle seat. The pump rotor and rod are removable through the passage while leaving the pump stator in place upstream of the valve. | 4 |
This application is a continuation application of U.S. patent application Ser. No. 10/727,049, filed Dec. 4, 2003, which is abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a static mixer comprising mixing elements for separating the components to be mixed into a plurality of streams, as well as means for the layered junction of the same, including a transversal edge and guide walls that extend at an angle to said transversal edge, as well as deflecting elements arranged at an angle to the longitudinal axis and provided with openings.
PRIOR ART
A static mixer of this kind is e.g. known from U.S. Pat. No. 5,851,067. This patent in turn is a further development of U.S. Pat. No. 5,944,419. These references disclose a mixer that is divided into chambered strings; according to the first cited U.S. patent, four chambered strings are created by four alternately disposed passages and the mixer further comprises re-layering chambers. In the second cited mixer, two flanges or alternatively two pairs of flanges crossing one another are disclosed with passages disposed in such a manner that respective bottom section plates are situated above respective openings.
Although mixers of this kind achieve a better mixing of the components with reference to its length and exhibit a smaller pressure drop than conventional mixers using mixing helixes, they include relatively large dead volumes in which the composition will harden, thereby leading to an eventual plugging of the mixer.
SUMMARY OF THE INVENTION
On the background of this prior art, it is the object of the present invention to provide a static mixer achieving a high mixing efficiency with reduced dead volumes and reduced pressure drop. This object is attained by a static mixer wherein said mixing element comprises a transversal edge and a following transversal guide wall and at least two guide walls ending into a separating edge each with lateral end sections and with at least one bottom section disposed between said guide walls, thereby defining at least one opening on one side of said transversal edge and at least two openings on the other side of said transversal edge.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be explained in more detail hereinafter with reference to drawings of exemplary embodiments.
FIG. 1 schematically shows a first exemplary embodiment of a mixer of the invention in a perspective view,
FIG. 2 schematically shows the starting position prior to mixing,
FIG. 3 shows a corresponding mixing diagram,
FIG. 4 shows a flow diagram of the mixing operation,
FIG. 5 shows the mixer of FIG. 1 in the inverse flow direction,
FIG. 6 schematically shows the starting position of the mixer of FIG. 5 prior to mixing,
FIG. 7 shows a mixing diagram relating to FIG. 6 ,
FIG. 8 shows a flow diagram of the mixer of FIG. 5 in the mixing operation,
FIG. 9 schematically shows a second exemplary embodiment of a mixer of the invention in a perspective view,
FIG. 10 shows the starting position prior to mixing,
FIG. 11 shows a diagram of the mixing operation in the mixer of FIG. 9 ,
FIG. 12 shows a flow diagram of the mixing operation in the mixer of FIG. 9 ,
FIG. 13 shows a combination of mixing elements according to the invention and of a mixing helix known per se in the prior art,
FIG. 14 shows a detail of an alternative embodiment of FIG. 9 ,
FIG. 15 schematically shows another exemplary embodiment of a mixer of the invention,
FIG. 16 shows a flow diagram of the mixing operation in the mixer of FIG. 15 , and
FIG. 17 shows an enlarged detail of the mixer of FIG. 15 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 illustrates a detail of a first exemplary embodiment of a mixer 1 of the invention that comprises a number of identical mixing elements 2 , 2 ′, and 2 ″, which are superimposed on one another while each successive element is rotated by 180° with respect to the longitudinal axis. Mixing enclosure 3 is schematically shown at one end.
Seen in the flow direction, i.e. from the bottom of the drawing, one end of each individual mixing element 2 comprises a transversal edge 8 of a transversal guide wall 8 ′ that is followed by two end sections 6 and 7 extending perpendicularly thereto and including complementary lateral openings 11 and 12 , and by a bottom section 9 and a complementary bottom section opening 10 , the latter extending between two guide walls 4 ′, 5 ′ each of which ends in a respective separating edge 4 , 5 , where the guide walls are aligned in parallel with the longitudinal center axis. In the present example, the end sections extend over half the length of the separating edges. The openings, resp. their cross-sectional areas, and the length of the webs essentially determine the pressure drop between the inlet and the outlet of the mixer.
The mixing element 2 ′ following mixing element 2 comprises the same components and structures, but it is superimposed on first mixing element 2 in a position rotated by 180° with respect to the longitudinal axis. The following mixing elements are also identical to mixing element 2 and arranged one after another while rotated by 180° each as seen in the longitudinal direction. The flow direction is indicated by arrow 13 .
FIG. 2 indicates the distribution of the two components G and H at the mixer entrance, each component being supplied from a container of a double cartridge or a dispensing appliance having separate outlets, see FIG. 13 . In the present example, according to the flow direction, the mixer entrance is shown at the bottom. After their entrance on either side of transversal edge 8 , the components G and H spread along transversal guide wall 8 ′ and are divided into three streams by guide walls 4 ′, 5 ′, so that six streams AG, BG, CG and AH, BH, and CH are finally produced, to which respective chambers DG, EG, FG; DH, EH, FH may be associated in the mixer.
During further dispensing, the six streams reach the following mixing element 2 ′. In the process, on one side of the transversal edge, the mixed and spread streams AG, BG, and CG are displaced through lateral openings 11 and 12 , and on the other side of the lateral edge, the spread streams AG, BH, GH are displaced through bottom opening 10 , as indicated in FIG. 3 schematically. Thus, at the end of element 2 , the mixed streams A 1 .G and C 1 .G with B 1 .G as well as A 1 .H and C 1 .H with B 1 .H=A 1 . 1 and C 1 . 1 with B 1 . 1 and A 1 . 2 and C 1 . 2 with B 1 . 2 are obtained according to the diagram of FIG. 3 . After having reached the second mixing element 2 ′, the mixed streams spread on either side of the lateral edge.
Then, the mixed and spread streams A 2 . 1 , B 2 . 1 , and C 2 . 1 are displaced outwards through lateral openings 11 and 12 , and the mixed streams A 2 . 2 , B 2 . 2 , and C 2 . 2 are displaced inwards through bottom opening 10 , as follows from FIG. 3 , whereupon these streams are spreading again.
In the next step, the displacement occurs in the other direction, i.e. streams A 3 . 1 , B 3 . 1 and C 3 . 1 are displaced inwards and A 3 . 2 , B 3 . 2 and C 3 . 2 outwards, as shown in FIG. 3 as well. Again, when entering the following element, the components spread on both sides of the lateral edge and are subsequently displaced again to reach the following mixing element.
The arrangement and the construction of the mixing elements result in a three phase sequence of the mixing process, in which the composition is first divided, then spread and subsequently displaced, only to be divided, spread, and displaced again in the following step.
This is shown in the diagram of FIG. 4 , in which the three steps of dividing, displacement and spreading are illustrated in three stages. In the diagram of FIG. 4 , separating is symbolized by I, displacement by II, and spreading by III, while the three mixing elements resp. mixing stages are designated by 2 , 2 ′, 2 ″. This diagram clearly shows that in mixing element 2 , the two components G and H are first divided into two and subsequently into three respective streams, i.e. into six streams AG, BG, CG and AH, BH, GH, then on the one side three mixed streams are displaced through the two lateral openings as two streams and on the otzher side the three other mixed streams are displaced through bottom opening 10 to form a single stream, and then again to be spread as three mixed streams.
In an alternative embodiment for a larger mixer, more than two separating edges and guide walls may be provided, e.g. three separating edges and guide walls, which in the case of two components divide the material into more then six streams, while the bottom walls resp. openings are arranged in alternate directions resp. mutually offset. Also, as in the preceding example, a transversal edge is provided, so that the streams are divided into two portions. The result is an analogous configuration of a mixing element comprising more than one transversal edge and more than two separating walls.
Alternatively, it is also possible to operate the mixer in the reversed direction with respect to the flow direction, so that the material first reaches the separating edges rather than the transversal edge. Thus, the composition is first divided into three parts and then, during its passage through the two openings, into two parts. In this inverse flow direction, the two outer streams unite and spread on one half of the transversal edge while the two middle streams unite and spread on the other half of the transversal edge.
In FIGS. 5 to 8 , mixer 1 is reversed by 180° with respect to FIG. 1 while the flow direction remains the same. For a better understanding, the individual components of the mixing element are listed again. At one end, seen from below in the direction of flow, the individual mixing element 2 comprises two separating edges 4 and 5 pertaining to respective guide walls 4 ′, 5 ′, which are aligned in parallel to the longitudinal center axis and comprise, perpendicularly thereto and on either side of the guide walls, two end sections 6 and 7 and a bottom section 9 situated between the guide walls and extending over half of the guide walls. Perpendicularly to the end sections, at the center of the guide walls, a transversal guide wall 8 ′ is arranged which comprises a transversal edge 8 at the other end of the mixing element.
The two end sections and the bottom section are complementarily associated with bottom section opening 10 between the guide walls and with the two lateral openings 11 and 12 on either side of the guide walls. The openings, resp. their cross-sectional areas, essentially determine the pressure drop between the inlet and the outlet of the mixer.
The mixing element 2 ′ following mixing element 2 comprises the same components and structures and is disposed on first mixing element 2 in a position rotated by 180° with respect to the longitudinal axis. Likewise, the following mixing elements are also arranged one after another in positions rotated by 180° each with respect to the longitudinal axis. The flow direction is indicated by arrow 13 .
In FIG. 5 , the distribution of the two components G and H at the mixer inlet is indicated, each component being supplied from a container of a double cartridge or a dispensing appliance having separate outlets, see FIG. 13 . In the present example, according to the flow direction, the mixer inlet is shown at the bottom. When entering the first mixing element 2 , the two components are divided by separating edges 4 and 5 into six streams AG, BG, CG and AH, BH, and CH.
During further dispensing, the six streams reach the following mixing element 2 ′. In the process, the respective pairs of streams A 1 .G and A 1 .H, B 1 .G and B 1 .H, and C 1 .G and C 1 .H=A 1 . 1 and A 1 . 2 , B 1 . 1 and B 1 . 2 , and C 1 . 1 and C 1 . 2 are mixed with one another according to FIG. 7 while due to the geometrical structure of mixing element 2 , stream A 1 . 1 displaces stream A 1 . 2 to reach the following mixing element through lateral opening 11 , stream B 1 . 2 displaces stream B 1 . 1 to reach the following mixing element through bottom section opening 10 , and stream C 1 . 1 displaces stream C 1 . 2 to reach the following mixing element through lateral opening 12 . When they arrive at the second mixing element 2 ′, the mixed streams B 2 . 1 and B 2 . 2 spread on one side of transversal edge 8 on the entire half A 2 . 1 -B 2 . 1 -C 2 . 1 , and likewise, the two mixed streams A 2 . 1 , A 2 . 2 and C 2 . 1 , C 2 . 2 spread on the other side of transversal edge 8 on the half A 2 . 2 , B 2 . 2 , and C 2 . 2 shown at the front of the Figure.
In the next step, a displacement in the other direction results, i.e. stream B 2 . 1 displaces stream B 2 . 2 , stream A 2 . 2 displaces stream A 2 . 1 , and stream C 2 . 2 displaces C 2 . 1 , as appears in FIG. 3 as well. Again, when entering the following mixing element, the components spread on a respective half and are subsequently displaced again to reach the following mixing element.
Here also, the arrangement and construction of the mixing elements result in a three phased sequence of the mixing process in which the composition is first divided, then displaced and finally spread, only to be divided, displaced, and spread again in the following step.
This follows from the diagram of FIG. 8 , in which the three steps of dividing, displacing, and spreading are illustrated in three stages. In the diagram of FIG. 8 , separating is symbolized by I, displacing by II, and spreading by III, while the three mixing elements as well as the corresponding mixing stages are designated by 2 , 2 ′, 2 ″. This diagram clearly shows that in mixing element 2 , the two components are divided into six streams, then a respective stream displaces the other one to spread towards the second mixing element 2 ′ in such a manner that the central streams form one half on one side of transversal edge 8 and transversal guide wall 8 ′ while the two outer pairs of streams jointly form the other half on the other side of the transversal edge and the transversal guide wall.
The mixers described above not only provide an intimate mixing of the materials but first of all a lower pressure drop as well as reduced dead volumes as compared to other mixers mentioned in the introduction.
Based on this simplified discussion of the schematic mixing operations, the following variations are possible: In these exemplary embodiments, mixers having rectangular resp. square cross-sections have been described, and the two impinging components have the same cross-sectional area. However, this need not always be the case, but any cross-sectional, resp.volume stream ratio of the two components G and H may be chosen at the inlet section, e.g. between 1:1 and 1:10, whereby the dimensions of the mixing elements remain the same. It is however possible to envisage specially adapted mixing elements. This means that the transversal edge need not be arranged on the center line of the mixing element. The same applies to the distance between the separating edges and the guide walls.
Furthermore, the separating edges and guide walls may be arranged at a mutual angle, and likewise, the end sections and the bottom section as well as the transversal edge may be arranged at a mutual angle, so that the openings are not necessarily rectangular or square. Also, the edges, e.g. the transversal edge, may incorporate a bend. The mixing elements need not be arranged one after another in positions rotated by 180°, but any angle from 0° to 360° is possible.
It is also possible to arrange the previously described mixing elements in an enclosure having a cross-section other than rectangular, e.g. in a round, an orbicular, resp. cylindrical, a conical, or an elliptic enclosure.
Whereas the previously described mixing elements provide good mixing properties, the walls arranged at an angle still include dead volumes giving rise to cured material in spite of the improved design. A further reduction of the dead volume is provided by a mixer having mixing elements with curved walls. A mixer of this kind is represented in FIGS. 9 to 12 .
FIG. 9 shows a mixer 14 with a regular cylindric housing as a particular case of a round mixer having mixing elements with curved walls, including mixing elements 15 , 15 ′, and 15 ″ and enclosure 16 . In analogy to the first mixer 1 , at one of its ends, i.e. at the bottom as seen in the flow direction, mixing element 15 comprises a transversal edge 21 where two guide walls 17 ′, 18 ′ originate which end in respective separating edges 17 , 18 . The guide walls each comprise a respective end section 19 and 20 with lateral openings 24 , 25 , a bottom section 22 , and a complementary bottom section opening 23 .
The individual sections are not as clearly demarcated here as in the first exemplary embodiment. In contrast to the rectangular mixing element 2 , the two guide walls 17 ′, 18 ′ form a curved and continuous transition between separating edges 17 and 18 situated at one end thereof and transversal edge 21 at the other end. This curved configuration of the guide walls, resp. their transition to the transversal edge appears in FIG. 9 , the schematized transition being shown in FIG. 12 .
The operation of this second exemplary embodiment is the same as in the first example. In analogy to the latter, the material stream consisting of the two components G and H is divided into a total of six streams AG, BG, CG, AH, BH, and CH as it leaves the first mixing element 15 .
In this example, the mixing operation is effected in analogy to the first exemplary embodiment, whereas the guide walls are no longer arranged in a sharp, rectangular disposition but run towards each other in a V-shaped configuration and have a curved shape. The mixing principle according to FIG. 11 is the same as in the first example, i.e. the central stream BG=B 1 . 1 in FIG. 11 mixes with the two other streams AG=A 1 . 1 in FIG. 11 and CG=C 1 . 1 in FIG. 11 and is displaced through lateral openings 24 , 25 , and spreads while on the other side of the transversal edge, the two outer streams AH=A 1 . 2 and CH=C 1 . 2 mix with central stream BH=B 1 . 2 are displaced through bottom section opening 23 , and spread. Due to the curved construction and the V-shaped arrangement of the guide walls, dead volumes are substantially reduced, thereby resulting in reduced losses. On the other hand, this arrangement results in a further reduced pressure drop.
It is conceivable in this exemplary embodiment that the two guide walls 17 ′, 18 ′ are provided at the transition to transversal wall 21 with an additional web 152 disposed in the longitudinal axis and transversally to the transversal wall, which would theoretically divide the material into three rather than two parts at the exit near the transversal wall, see FIG. 14 illustrating a mixing element 151 . However, such an additional web offers no advantages but rather the inconvenience that the material may not spread on that side. It is also possible to provide such a web in the first, rectangular mixer, i.e. below floor 9 and along transversal edge 8 . However, the following considerations and the claims do not take account of this additional partition.
Also, the diagram of FIG. 12 will be interpreted in analogy to the diagram of FIG. 4 with the difference that the perpendicular guide walls 4 ′, 5 ′ provided according to FIG. 4 are V-shaped here and end in the transversal edge.
In analogy to the first example, the cross-sectional, resp. volume stream ratios of the components G and H may be different from 1:1, and most importantly, the guide walls leading from the separating edges to the transversal edge may assume a multitude of geometrical shapes while the mixing elements may be reversed to the shown arrangement with regard to the flow direction. Also, the mixing principle is the same in each case, i.e. the central streams mix with each other and spread on one side of the transversal edge, and then the two outer pairs of streams spread on the respective other side of the transversal edge. Furthermore, the successive mixing elements need not necessarily be rotated by 180° each with respect to the longitudinal axis as shown in FIG. 9 but may be disposed in any orientation.
In the exemplary embodiment of FIG. 13 , a novel mixer arrangement is shown which achieves particularly good results with the described mixing elements. FIG. 13 shows a mixer 36 , mixer enclosure 16 and the mixer entrance with inlets 32 and 33 and outlet openings 34 and 35 . As in the mixers of the prior art using mixing helixes, entrance edge 31 of the first helix mixing element 28 extends transversally across the two outlet openings 34 , 35 . The two separating edges of first mixing element 15 of first mixing group 27 are disposed transversally to outlet edge 30 of the first helix mixing element. The first mixing group 27 consists of the mixing elements 15 , of which four are illustrated here by way of example. This group is followed by the second helix mixing element 28 ′, which in turn is followed by a second mixing group 27 ′. This second mixing group also consists of four mixing elements 15 ′, which however are reversed by 180° in the direction of flow against the first mixing group, i.e. with the transversal wall directed towards the inlet, whereby this group has a similar effect as that of FIG. 9 .
Furthermore, it follows from FIG. 13 that transversal edge 21 of the last mixing element of each mixing group is perpendicular to entrance edge 31 ′ of mixing helix element 28 ′. The periodical insertion of a mixing helix element serves the purpose of efficiently peeling the material from the walls and of re-layering it, thereby providing a further improvement of the mixing efficiency.
In FIG. 13 , three mixing groups and three mixing helix elements are shown, but it is understood that the number of mixing groups and mixing elements may vary according to the intended purpose. Thus, both the number of mixing elements per mixing group and the number of mixing helix elements between the mixing groups may vary. All considerations concerning the mixing operation and the application of conventional mixing helixes also apply for the homogenization of materials and for mixing arrangements using mixing elements according to FIG. 15 .
The exemplary embodiment of FIGS. 15-17 is based upon the exemplary embodiment of FIG. 1 with straight element walls, the mixing elements however being arranged in a regular cylindrical housing. In this exemplary embodiment, several features are indicated which provide both an improvement of the mixing action and a reduction of the dead volumes resp. of the losses associated therewith, and thus allow a substantially increased overall efficiency. It is understood that not all of these features need be provided in all mixing elements or mixing groups at the same time.
FIG. 15 shows a mixing element arrangement 40 , whereby the housing is not shown, including inlet portion 41 with inlets 42 , 43 and outlets 42 ′, 43 ′ as well as mixing section 44 with the mixing elements. Up to the first transversal edge 45 , the components are separated by a separating wall 46 . In this exemplary embodiment, five mixing elements 47 a - 47 e are integrated in a first mixing group 47 , while the second mixing group 48 comprises two mixing elements 48 a and 48 b and the following mixing group 49 again includes five mixing elements 49 a - 49 e.
Using the mixer according to FIG. 1 , 15 or 17 it may be advantageous to provide that the height ZL of guide walls 50 , 51 , which are reached by the material after the transversal guide wall, is greater than the height ZQ of the transversal guide walls, e.g. by a preferred factor comprised between 1.1 and 2.0, more particularly 1.5. This lengthening of the double guide walls provides an improved alignment of the material, which is thereby allowed more time to spread before being divided again. Furthermore, the lengthening of the double guide walls results in a reduction of the number of mixing elements required to achieve an equal or better mixing quality.
In analogy, when using the mixer according to FIG. 5 in the reversed flow direction it may be advantageous to provide for a greater height ZQ of the transversal guide wall, reached after the guide walls by the material, than the height ZL of the guide walls, also with a preferred ratio of 1.1 to 2.0, in particular 1.5.
A second feature common to all mixing elements are measures for reducing the dead zones, which are particularly important in the case of straight walls and cause volume losses and local curing of the material. To this end, such dead zones are filled in. Different dead zone obturations TZV are indicated especially in FIG. 17 . Thus, bottom section 9 comprises dead zone obturations TZV 1 of a first type that are directed towards the preceding mixing element. The mixing elements having no inclined webs, i.e. mixing elements 47 a - 47 e and 49 a - 49 e , also comprise dead zone obturations TZV 2 on the inwardly facing sides of the bottom sections. On the outside of guide walls 50 and 51 a third and fourth type of dead zone obturations TZV 3 and TZV 4 are provided in those locations where no inclined webs are present.
At straight walls, wall layers are formed that cause layer defects during layer formation. For the detachment of such layers, for the promotion of the longitudinal mixing action in the direction of the double guide walls, and for equalizing the concentrations, inclined webs are provided on the inside and on the outside of the guide walls.
In the mixer of FIGS. 15 and 17 , these inclined webs are attached to the central mixing group 48 where internal inclined webs 52 and external inclined webs 53 are visible, both of which are attached to guide walls 50 and 51 of mixing elements 48 a and 48 b.
Wall layers appear not only on the guide walls but also on the inner wall of the mixer enclosure. To optimize the layer formation, longitudinal webs are provided which connect the double guide walls on the outside. The longitudinal webs need not be provided in all mixing groups. In the exemplary embodiment of FIGS. 15 and 17 , the longitudinal webs 54 are attached to the first and second mixing groups 47 , 48 , but they might as well be attached to the third or to any other mixing group, or alternatively in the same way as in mixing group 48 .
The suggested measures resp. features are preferably used jointly, but embodiments where only some of the measures are applied are conceivable too.
The flow diagram of the mixing operation is shown in FIG. 16 .
At A, the two components spread on the respective side of transversal guide wall 55 . At B, the portion on the right side moves towards the center and spreads over the entire length of guide walls 50 , 51 while the portion on the left side divides into two halves and forms the outer two thirds. At C, these three streams are divided transversally. At D, the left half is guided towards the center and spreads over the entire length of the guide walls while the portion on the right side is divided and the halves reach respective sides of the guide walls, whereupon a transversal edge follows again, etc.
The following claims are applicable in the simplified case where the transversal edges and guide walls do not comprise any webs as web 152 , which do not change the general mixing principle of the mixing elements. Moreover, the definition of a transversal wall includes a possible duplication of the transversal edge into two parallel transversal walls as this does not change the mixing principle either. | The static mixer comprising mixing elements for separating the material to be mixed into a plurality of streams and a mechanism for the layered junction of the same, a transversal edge and guide walls that extend at an angle to said transversal edge, as well as deflecting elements arranged at an angle to the longitudinal axis and provided with openings, includes mixing elements comprising a transversal edge and a following transversal guide wall and at least two guide walls with lateral end sections and at least one bottom section disposed between said guide walls, thereby defining at least one opening on one side of said transversal edge and at least two openings on the other side of said transversal edge. In addition to a high mixing efficiency and a low pressure drop, a mixer of this kind provides reduced dead volumes and is thus more effective than mixers of the prior art. | 1 |
BACKGROUND OF THE INVENTION
Generally a vial is used in such a way that a rubber stopper press-fitted to the vial neck is covered with a cap, a predetermined portion of the cap is then removed, and an injection needle is passed through such removed portion.
In a conventional cap, a through-bore has been formed in the top plate of the cap main body made of metallic material and a resinous removable member has been attached on this through-bore of the top plate. When intending to open the cap, this removable member is raised up to break the attached portions thereof. With such arrangement, however, the attached portions may not be provided with good airtightness and it is not possible to heat-sterilize the cap with the removable portion remained as attached to the cap main body, since the removable member is made of resin. Accordingly, such cap has not sealingly been fitted in the aseptic condition to the rubber stopper and subsequently the rubber stopper portion through which an injection needle is passed, has not been covered in the aseptic condition. This has required a sterilization method other than heat-sterilization, so that complicated and therefore expensive sterilizing equipment has been necessary. Moreover, since such conventional cap comprises a metallic cap main body and a resinous removable member, complicated manufacturing equipment has also been required.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide a bottle cap in which, by merely pushing up the periphery of the removable member with the thumb of the hand holding a bottle, a predetermined portion of the top plate of the cap main body may be broken, so that the removable member may be removed with one hand, thereby to facilitate the cap opening procedures to a great extent.
It is another object of the present invention to provide a bottle cap in which the cap main body and the removable member may be formed by stamping and securely fixed to each other by cold pressure welding, thereby to provide good airtightness to prevent the entrance of bacteria, as well as to facilitate the manufacturing of such cap.
It is a further object of the present invention to provide a bottle cap in which the cap main body and the removable member are made of the same metallic material such as aluminium, thereby to facilitate fixing of the cap main body to the removable member by the cold pressure welding and to permit such cap to be heat-sterilized just before sealingly fitted to a vial after having been delivered from factory, whereby such cap may sealingly be fitted in the aseptic condition to a rubber stopper, thereby to simplify cap sterilizing equipment and to facilitate sterilizing procedures.
It is still another object of the present invention to provide a bottle cap in which upwardly expanded portions are formed within the inside of the pressed concave portions in the annular shape formed in the removable member and the cap main body, thereby to easily absorb expansion of the rubber stopper due to the internal pressure in a vial.
It is a still further object of the present invention to provide a bottle cap in which pressed concave portions in the annular shape formed by cold pressure welding for securely fixing the top plate of the cap main body and the base plate of the removable member to each other, are formed thin so that, when opening the cap, the annular pressed concave portion of the top plate of the cap main body is easily broken to facilitate the opening procedure.
It is a still further object of the present invention to provide a bottle cap in which annular scores are formed in the under surface of the pressed concave portion of the top plate of the cap main body, thereby to permit the cap to be easily opened with a small and constant opening force, and such scores may be formed simultaneously with forming the pressed concave portions for fixing the cap main body top plate to the removable plate,
thereby to facilitate the manufacturing of such cap.
It is a still further object of the present invention to provide a bottle cap in which an annular projection is formed at the under surface of the top plate of the cap main body at the outside of the annular pressed concave portion thereof so as to be press-contacted to the upper surface of a rubber stopper press-fitted to the bottle neck, whereby the top plate of the cap main body perfectly come in close contact with the rubber stopper, thereby to prevent the entrance of foreign matter such as bacteria or dust into the pressed concave portions from the clearance between the rubber stopper and the top plate.
It is a still further object of the present invention to provide a bottle cap in which a rolled-in ring is formed at the periphery of the removable member, thereby to reinforce the periphery of the removable member, simultaneously with forming a contact member to which the finger is applied when intending to remove such removable member, thereby to facilitate the removing operation.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be further described by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a plan view of a first embodiment of a bottle cap according to the present invention;
FIG. 2 is a front view with portions broken away of FIG. 1;
FIG. 3 is a section view showing a vial to which the cap in FIG. 2 is sealingly fitted;
FIG. 4 is a plan view of main portions of a second embodiment of a bottle cap according to the present invention;
FIG. 5 is a vertical section view of FIG. 4; and
FIG. 6 is a section view showing a vial to which the cap in FIG. 5 is sealingly fitted.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The description will first be made of a first embodiment of a bottle cap according to the present invention, with reference to FIGS. 1 and 2.
A cap main body 1 made of metallic material such as aluminium has a top plate 2. A side wall 3 is formed by downwardly turning the periphery of the top plate 2. A removable member 4 is made of the same metallic material, such as aluminium, as material of the cap main body 1. This removable member 4 has a base plate 5. A side plate 6 is formed by upwardly turning the periphery of the base plate 5. A rolled-in ring 7 is outwardly turned at the upper edge of the side plate 6. Pressed concave portions 8 and 8' are formed in the annular shape at the center portions of the top plate 2 of the main body 1 and the base plate 5 of the removable member 4 by cold pressure welding of the base plate 5 of the removable member 4 overlapped onto the top plate 2 of the cap main body 1. Thus, the cap main body 1 is integrally secured to the removable member 4 by such pressed concave portions 8 and 8' formed by the cold pressure welding. It is to be noted that the pressed concave portions 8 and 8' are formed thin. Expanded convex portions 5' and 2' of a generally spherical shape are formed within the annular pressed concave portions 8 and 8' of the base plate 5 and the top plate 2. The outer diameter of the rolled-in ring 7 is preferably the same as or slightly larger than the outer diamter of the side wall 3 of the cap main body 1.
A description now made of the cap shown in FIGS. 1 and 2 fitted to a vial, with reference to FIG. 3.
Mounted to the neck 10 of a vial 9 is a rubber stopper 12 having a cylindrical portion 11 press-fit to the inner wall of the neck 10. The cap main body 1 of a sterilized cap is then put on the rubber stopper 12 and the vial neck 10. The lower portion 13 of the side wall 3 of the cap main body 1 is rolled in to the lower surface of the vial neck 10 for preventing the rubber stopper 12 from coming up from the neck 10, as well as for sealingly fitting the cap to the neck 10 through the rubber stopper 12.
When opening the cap, the vial 9 is held with one hand and the rolled-in ring 7 is obliquely pushed up. The thin pressed concave portion 8 of the top plate 2 of the cap main body 1 is then broken, so that the expanded portion 2' of the top plate 2 is removed from the top plate 2, thereby to form a circular bore in the top plate 2.
Accordingly, with the thumb of the hand holding the vial to which the bottle cap according to the present invention is sealingly fitted, the periphery of the removable member 4 may be pushed up, and such pushing operation alone permits the predetermined portion of the top plate 2 of the cap main body 1 to be broken away, thus realizing a one-handed removal of the removable portion thereby to facilitate the cap opening operation to a great extent.
Since the cap main body 1 and the removable member 4 may be formed by stamping and securely fixed to each other by cold pressure welding, a good airtightness may be provided to prevent the entrance of bacteria and also the manufacturing may easily be done.
Furthermore, since the cap main body 1 and the removable member 4 are made of the same metallic material, such as aluminium, they may readily be fixed to each other by cold pressure welding and be sterilized, for example by heating, just before being fitted to a bottle after having been delivered from the factory, thereby to simplify sterilizing equipment and to facilitate the sterilizing procedures.
In addition, since the upwardly expanded portions 2' and 5' are formed within the annular concave portions 8 of the cap main body 1 and the removable member 4, it is possible to absorb expansion of the rubber stopper 12 due to the internal pressure in the bottle.
Moreover, since the rolled-in ring 7 is formed at the peripheral edge of the removable member 4, the periphery of the removable member 4 may be reinforced and such rolled-in ring 7 may also serve as contact portion for the finger at the time of the cap opening operation, thereby to facilitate the opening procedures.
Although, in the embodiment discussed hereinbefore, the side plate 6 of the removable member 4 has been formed by upwardly turning the peripheral edge of the base plate 5, such side plate may also be formed by downwardly turning the peripheral edge of the base plate 5 so as to form a rolled-in ring by outwardly turning the lower edge of the side plate and to be press-contacted to the side wall 3 of the cap main body 1. Such press-contact serves to prevent the entrance of dust or dirt into the clearance between the top plate 2 of the cap main body 1 and the base plate 5 of the removable member 4.
It is to be noted that, when the cap main body 1 and the removable member 4 are made of Alumite, the stability of the press-welding by the cold pressure welding may be improved.
The description will then be made of a second embodiment of the present invention with reference to FIGS. 4 and 5.
A cap main body 14 is made of metallic material such as aluminium. This cap main body 14 has a top plate 15 of a circular shape. A cylindrical side wall 16 is formed by downwardly turning the peripheral edge of the top plate 15. An annular projection 17 is formed at the under surface of the top plate 15 near the peripheral edge thereof. A removable member 18 is made of the same metallic material, such as aluminium, as material of the cap main body 14. A circular base plate 19 of the removable member 18 has an inclined portion 20, which is formed by upwardly turning the peripheral edge of the base plate 19 on a slant. A side plate 21 is formed by downwardly turning the peripheral edge of the inclined portion 20. A rolled-in ring 22 is formed by inwardly turning the lower edge of the side plate 21. There is disposed a clearance 23 between the rolled-in ring 22 and the side wall 16 of the cap main body 14. Pressed concave portions 24 and 24' for the fixing purpose are formed in the annular shape at the center portions of the top plate 15 and the base plate 19 by cold pressure welding of the base plate 19 of the removable member 18 overlapped to the top plate 15 of the cap main body 14. By these pressed concave portions 24 and 24', the cap main body 14 is securely fixed to the removable member 18. Expanded convex portions 15' and 19' of a generally spherical shape are formed within these annular pressed concave portions 24 and 24' of the top plate 15 and the base plate 19'.
Scores 25 of an annular shape are formed in the under surface of the pressed concave portion 24 of the top plate 15 at the positions near the peripheral edge thereof, and such scores 25 are formed at the same time of forming the pressed concave portions 24 and 24' formed by cold pressure welding.
A description is now made of the cap shown in FIGS. 4 and 5 fitted to a vial, with reference to FIG. 6.
Mounted to the neck 27 of a vial 26 is a rubber stopper 29 having a cylindrical portion 28 which is press-fit to the inner wall of the neck 27. The cap main body 14, which is sterilized is fitted to the rubber stopper 29 and the neck 27. The lower end 30 of the side wall 16 of the cap main body 14 is rolled in to the bottle neck 27, thereby to prevent the rubber stopper 29 from coming up from the bottle neck 27, as well as to sealingly fit the cap to the bottle neck 27 through the rubber stopper 29.
When opening the cap, the vial 26 is held with one hand and the rolled-in ring 22 of the removable member 18 is obliquely pushed up. The center portion of the top plate 15 is then pushed up together with the base plate 19 and the scores 25 are broken, so that the center portion of the top plate 15 is removed from the top plate 15, thereby to form a circular bore in the top plate 15.
Accordingly, the second embodiment shown in FIGS. 4 and 5 may provide other effects in addition to those provided in the first embodiment shown in FIGS. 1 and 2. Since the scores 25 are formed in the under surface of the pressed concave portion 24 of the top plate 15 of the cap main body 14, namely since the scores 25 are formed in the under surface of the pressed concave portion 24 to which a cap opening force is directly applied, cap opening procedures may be easily performed with a small and constant force alone.
Moreover, the scores 25 may be formed simultaneously with forming the pressed concave portion 24 thereby to facilitate the manufacturing of the cap to a great extent.
Furthermore, since the annular projection 17 is formed at the under surface of the top plate 15 of the cap main body 14, this annular projection 17 is fittingly pressed to the upper surface of the rubber stopper 29, so that the top plate 15 perfectly comes in close contact with the rubber stopper 29, thereby to prevent dust or bacteria from entering the scores 25 from the clearance between the top plate 15 and the rubber stopper 29. | The present application discloses a bottle cap for a medicine bottle, such as a small bottle or vial or the like, in which the cap main body and a removable member made of the same metallic material are securely fixed to each other by cold pressure welding while forming therein pressed concave portions in an annular shape. Said cap main body and said removable member are provided within said pressed concave portions in the annular shape thereof with upwardly expanded portions. Thus, the present invention provides a good airtight cap which is easy to be manufactured and which can be heat-sterilized. | 1 |
RELATED PATENT APPLICATION
This application is a continuation of application Ser. No. 09/327,781, filed Jun. 7, 1999 now abandoned, which is a division of application Ser. No. 08/965,574, filed Nov. 6, 1997, now U.S. Pat. No. 5,965,027, and a continuation-in-part of application Ser. No. 08/756,681, filed Nov. 26, 1996, now U.S. Pat. No. 5,871,648.
FIELD OF THE INVENTION
The present invention relates to the high flow treatment and purification of wastewater containing silica. More particularly, the present invention relates to process and apparatus for removing silica from large quantities of wastewater using a combination of filter membranes and organic polymers.
BACKGROUND OF INVENTION
Many industrial operations generate large quantities of water containing silica. For instance, chemical mechanical polishing (CMP) processes, widely used in the manufacture of semiconductor devices, produce waste water streams containing high quantities of silica. CMP processes are used to polish the silicon-based wafer surface during various stages of semiconductor manufacture. Waste streams containing the polishing slurry and silica are produced during CNP. The silica must be removed before the water can be safely discharged to the environment or recycled within the facility.
Dissolved silica in industrial cooling water is a major problem. Silica is a scale forming material commonly found in cooling water which can foul heat exchangers, pipes, valves, pumps, and boilers. No known inhibitor, chelating agent or dispersant exists which will significantly control silica's tendency to form scale. When the silica concentration in a cooling water system exceeds its solubility limit of roughly about 150 to about 200 milligrams per liter, silica polymerizes to form scale. It may also react with multivalent cations, such as magnesium and calcium, to form scale.
Researchers have examined many different methods of removing soluble silica, including the use of ferric sulfate, calcium chloride, magnesium chloride, magnesium sulfate, magnesium oxide, aluminum hydroxide, sodium aluminate and activated alumina. Activated alumina has received much attention in processes for removing silica. See, U.S. Pat. No. 4,276,180 to Matson and U.S. Pat. No. 5,512,181 to Matchett. Other aluminum containing compounds such as sodium aluminate, aluminum sulfate, and aluminum chloride in an alkaline environment (pH greater than 8) have been used to remove soluble and colloidal silica. See, U.S. Pat. No. 5,453,206 to Browne. However, these processes are not capable of processing large volumes of wastewater through high flow mechanical systems because of degradation of particles and particulates below 5 micron in size.
Microfiltration systems have been considered to remove silica contaminants from wastewater. However, traditional microfiltration membranes having a pore size of about 0.5 microns rapidly clog with silica that was precipitated with conventional inorganic coagulants. Such particulates are consistently less than 1.0 micron in size. Moreover, the inorganic coagulants cannot aid in the precipitation of microfine colloidal silica. The partially formed floc will also deform and block the membrane pores, preventing flow.
There is, therefore, a need in the art for improved processes for removing silica from wastewater.
Such processes and systems are disclosed and claimed herein.
SUMMARY OF THE INVENTION
The present invention is directed to a process for removing silica from large volumes of wastewater. In the process, a wastewater stream containing silica is treated with an organic polymer. The coagulant reacts with the silica to form spherical particulates which agglomerate into clusters having a size greater than about 5μ. As used herein, a wastewater stream includes raw water containing silica as well as process water streams containing silica. organic and polymeric coagulants which can be used to achieve the desired particulate formation, such as polyacrylamides (cationic, nonionic, and anionic), epi-dma's (epichlorohydrin/dimethylamine polymers), DADMAC's (polydiallydimethylammonium chlorides), copolymers of acrylamide and DADMAC, natural guar, etc. The stoichiometric ratio of coagulant to silica is preferably optimized to result in acceptable silica removal at minimum coagulant cost. The required coagulant concentration will depend on several factors, including silica contaminant influent concentration, wastewater flow rate, silica contaminant effluent compliance requirement, coagulant/contaminant reaction kinetics, etc. For silica contaminants, the ratio of silicon to coagulant contaminant is typically in the range from 20:1 to 50:1, depending on the system, an preferably about 40:1. If small amounts of silica can remain in the effluent stream, then the ratio of silicon to coagulant can be 120:1 or even higher. The optimum mole ratio will also vary depending on the coagulant used. For instance, low molecular weight epi-dma and very high molecular weight epi-dma require from 3 to 5 times the dose to flocculate the silicon.
It has been found that the foregoing organic coagulants cause the silica to form well defined spherical particles having a typical particle size in the range from about 10μ to 90μ. The silica particles are easily separated from micro-filtration membranes enabling efficient silica removal without membrane degradation.
Small amounts of a supplemental coagulant can optionally be used in combination with the organic and polymeric coagulant to optimize the silica removal. Examples of typical supplemental coagulants include, aluminum chlorohydrate (“ACH,” Al n OH 2n−m Cl m , e.g., Al 4 OH 6 Cl 2 with a typical Al:Cl ratio of 2:1), sodium aluminate (NaAlO 2 ), aluminum chloride (AlCl 3 ), and polyaluminum chloride (“PAC,” Al 6 OCl 5 ). The typical mole ratio of silica to inorganic coagulant is about 25:1.
Treated wastewater is passed through a microfiltration membrane which physically separates the silica contaminant from the wastewater. Suitable microfiltration membranes are commercially available from manufacturers such as W.L. Gore, Koch, and National Filter Media (Salt Lake City, Utah). For instance, one GOR-TEX® membrane used in the present invention is made of polypropylene felt with a sprayed coating of teflon. The teflon coating is intended to promote water passage through the membrane. Such microfiltration membrane material has been found to be useful for many wastewater treatment systems. However, when used in a system for removing fluoride or silica, it has been observed that the coagulated particles adhere to the exterior and interior surface and plug the membrane. Backflushing was not effective in such cases.
The microfiltration membranes are used in a tubular “sock” configuration to maximize surface area. The membrane sock is placed over a slotted tube to prevent the sock from collapsing during use. A net material is placed between the membrane sock and the slotted tube to facilitate flow between the membrane and the slots in the tube. In order to achieve the extremely high volume flow rates, a large number of membrane modules, each containing a number of individual filter socks, are used.
The microfiltration membranes preferably have a pore size in the range from 0.5 micron to 5 micron, and preferably from 0.5 micron to 1.0 micron. By controlling the ratio of coagulant to silica contaminant, 99.99% of the precipitated contaminant particles can be greater than 5 microns. This allows the use of larger pore size microfiltration membranes. It has been found that the treated wastewater flow rate through 0.5 to 1 micron microfiitration membranes can be in the range from 150 gallons per square foot of membrane per day (“GFD”) to 600 GFD.
Solids are preferably removed from the membrane surface by periodically backflushing the microfiltration membranes and draining the filtration vessel within which the membranes are located. The periodic,. short duration back flush removes any buildup of contaminants from the walls of the microfiltration membrane socks. The dislodged solid material within the filtration vessel is flushed into a holding tank for further processing of the solids.
The wastewater treatment system disclosed herein is designed to provide compliance with the contaminant silica discharge effluent limits. Wastewater pretreatment chemistry creates insoluble silica contaminant particulates which are efficiently removed by the microfiltration membranes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a photomicrograph of the precipitated silica particles produced in Example 3 at 24,000×magnification.
FIG. 1B is a photomicrograph of the precipitated silica particles produced in Example 3 at 49,000×magnification.
FIG. 2A is a photomicrograph of the precipitated silica particles produced in Example 4 at 20,000×magnification.
FIG. 2B is a photomicrograph of the precipitated silica particles produced in Example 4 at 40,000×magnification.
FIG. 3 is a schematic representation of one wastewater pretreatment system.
FIG. 4 is a schematic representation of one wastewater microfiltration apparatus for high flow impurity removal.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to a process for removing silica contaminants from large volumes of wastewater. In operation, the wastewater is collected and pretreated with one or more organic polymer coagulants such that the;silica reacts with the coagulant(s) to form spherical particulates which agglomerate into clusters having a size greater than about 5μ. The chemical coagulants are preferably mixed with the wastewater using reaction vessels or static in-line mixers, although other mixing methods can be used.
The treated wastewater is then passed through a microfiltration membrane having a pore size in the range from 0.5μ to 5μ to remove the silica contaminant particulates. In such a system, wastewater flow rates in the range from 150 gallons per square foot of membrane per day (“GFD”) to 600 GFD are possible. The microfiltration membrane is periodically backflushed to remove solids from the membrane surface. The rejected solids are gravity collected in the filter vessel bottom and time cycle discharged to a settling tank for further sludge processing.
The microfiltration membranes are preferably provided in a cassette arranged module. The microfiltration membranes provide a positive particle separation in a high recovery dead head filtration array. The dead head filtration operates effectively at low pressures (4 psi to 15 psi, preferably 5 psi to 10 psi) and high flow rates, allowing 100% discharge of the supplied water with no transfer pumps needed. Solids which settle on the wall of the membrane during filtration are periodically backflushed away (and gravity settled) from the membrane surface to ensure a continuously clean filtration area. The individual cassette module design allows for easy replacement of the membrane modules.
Currently preferred filter socks useful with the present invention contain a teflon coating on a polypropylene or polyethylene felt backing material. Such socks are available from W. L. Gore. Another presently preferred filter sock manufactured by National Filter Media, Salt Lake City, Utah, consists of a polypropylene membrane bonded to a polypropylene or polyethylene felt backing. Membrane “failure” is due primarily to flux loss, not mechanical failure. Many operations deem it more cost-effective to replace the membrane socks instead of cleaning contaminants from the membrane.
The membrane life is important to the continuous operation and operational cost of the filtration system. The membranes manufactured by W.L. Gore and National Filter Media have been found to be robust and free of catastrophic failures at a temperature of 160° F. and a pH greater than 13. Anticipated operating conditions for the present invention are ambient temperature and pH between 5 and 11. A currently preferred operating pH range is between about 7.3 and 9.3, although good results are obtained ±1.0 pH unit from the optimum pH. It is presently preferred to adjust the pH before adding the organic coagulant. It is expected that membranes used according to the present invention will have a life equal to or greater than 18 months. The filtration system operates at a low pressure, preferably between 4 and 15 psi. Greater pressures are possible; however, the higher the pressure, the quicker the membrane loss of flux. Although the currently preferred operating pressure is below about 25 psi, excellent results have been obtained using the organic coagulants with commercially available high pressure microfiltration systems which operate at pressures between 30 and 80 psi. Existing microfiltration systems using conventional inorganic coagulants can be retrofitted for use with the organic coagulants to obtain dramatically improved performance.
The following examples are offered to further illustrate the present invention. These examples are intended to be purely exemplary and should not be viewed as a limitation on any claimed embodiment.
EXAMPLE 1
A 15 gpm pilot scale system was used to process wastewater containing fluoride and a combined flow of fluoride and silica. A 38% sodium aluminate solution at a ratio of 0.23:1 Al:F and 50% aluminum chlorohydrate at a dose of 35 ppm to aid in the removal of the fluoride, total dissolved solids (TDS), total suspended solids (TSS), and some of the other present salt forms. The precipitate was flocculated with a medium charge (25±5 mole percent), medium molecular weight anionic polyacrylamide polymer for ease of filtering or settling. This yielded very low to non-detectable effluent values of fluoride and Silt Density Indices (SDI) below 3.0. The filtration membrane was a 0.5μ polypropylene bonded membrane obtained from National Filter Media. The membrane flux was measured at 650 to 800 GFD at a vessel operating pressure less than 9 psi. The results are reported below in parts per million.
Time
Period
Influent F
Effluent F
A
130.0
1.86
B
191.5
21.7
C
142.2
2.13
D
120.0
0.72
E
156.5
1.41
F
125.7
0.79
G
60.93
0.97
H
206.25
0.95
I
133.3
0.39
J
112.9
0.85
K
78.2
3.96
L
133.5
3.96
Average
132.6
3.8
Min
60.93
0.39
Max
206.25
21.7
Time
Period
Influent F + SiO 2
Effluent F + SiO 2
A
264.0
0.24
B
172.0
0.26
C
140.0
0.31
D
153.0
0.39
E
98.0
0.36
F
89.0
0.29
Average
152.7
0.31
Min
89.0
0.24
Max
264.0
0.39
EXAMPLE 2
A 15 gpm pilot scale system was used to process waste-water containing. silica. The silica was present in dissolved and colloidal silica form in the waste stream. A 38% sodium aluminate solution at a ratio of 0.45:1 Al:Si, 46% aluminum sulfate at constant dose of 45 ppm, 50% aluminum chlorohydrate at a dose of 25 ppm, and a 20% epichlorohydrin/dimethylamine polymer (a high charged, low molecular weight cationic epi-DMA product) at a dosage of 0.25-1.0 ppm to aid in the removal of the silica, TDS and TSS. This formed a well defined particle for filtering or settling. This yielded very low to non-detectable effluent values of the silica and Silt Density Indices (SDI) below 3.0. The filtration membrane was a 0.5 micron polypropylene felt with a PTFE (polytetrafluoroethylene) coating obtained from W.L. Gore. The membrane flux ranged from 175 GFD to 400 GFD at a vessel operating pressure less than 15 psi. The results are reported below in parts per million.
Time
period
Influent SiO 2
Effluent SiO 2
A
140
0.443
B
160
0.33
C
125
0.37
D
153
0.39
E
177
0.36
F
165
0.29
Average
153
0.364
Min
125
0.29
Max
177
0.443
EXAMPLE 3
A 3-5 gpm bench scale system)was used to process waste-water containing silica. The silica-containing waste stream was obtained from a commercially available CMP slurry sold by Rodel, known as ILD 1300. The ILD 1300 slurry was diluted according to manufacturer's instructions, and it was found to contain about 1380 ppm Si, measured by graphite furnace atomic absorption, and about 70 ppm ammonium (NH 4 ), measured by ion chromatography. One liter of the waste stream weighted about 993.7 grams. The silicon was present in the waste stream as dissolved and colloidal silica. The waste stream was adjusted to a pH of about 8.58 by adding small amounts of sodium hydroxide and sulfuric acid. The waste stream was mixed for about 3 minutes while the pH was adjusted. 2.09 g of a 20% by weight solution of epi-DMA, an epichlorohydrin/dimethylamine polymer having an average molecular weight of 250,000±50,000 (EnChem Lot I-1396/423/MIC) and 0.19 g of dry aluminum chlorohydrate were added to one liter of the waste stream and mixed for about 20 minutes.
The reaction mixture was pumped at a pressure of about 6 psi through a two foot long filter sock having a diameter of about 3.5 inches. The membrane flux was estimated at 189 GFD. The filter sock contained a GOR-TEX® membrane (Lot. No. 66538-3-786) obtained from W.L. Gore. The membrane had a PTFE (polytetrafluoroethylene) coating on polypropylene felt having a 0.5μ pore size (1.5μ absolute).
The filter membrane effluent was collected, and it was found to contain about 15.5 ppm Si, measured by graphite furnace atomic absorption, and about 70 ppm ammonium (NH 4 ), measured by ion chromatography.
The solids were collected from the filter surface and air dried for 24 hours. The recovered solids formed well defined spherical particles which were easily removed from the filter membrane surface. The dried and ground solids were analyzed, and the results are reported below in weight percent.
ILD 1300
Results
Loss on Drying
45.53%
Carbon
3.84%
Hydrogen
1.04%
Nitrogen
1.41%
Silicon
36.74%
Aluminum
2.30%
Other ingredients in the recovered solid, such as sodium, potassium, and unknown proprietary ingredients of ILD 1300, were not analyzed.
FIG. 1A is a scanning electron micrograph (SEM) of the resulting spherical silica particles taken at 24,000×magnification. FIG. 1B is a SEM of the product of FIG. 1A taken at 49,000×magnification. The particles had a typical particle size in the range from 0.05μ to 0.15μ. Although the spherical particles are smaller than the membrane pore size, it has been found that the particles agglomerate to form large clusters that do not pass through the membrane. The clusters have an average size in the range from 10μ to 300μ. EDX analysis of the sample indicated the presence of silicon and aluminum in the sample, wherein the concentration of silicon was much greater than the concentration of aluminum.
EXAMPLE 4
A 3-5 gpm bench scale system was used to process waste-water containing silica. The silica-containing waste stream was obtained from a commercially available CMP slurry sold by Hoescht, known as KLEBOSOL. The KLEBOSOL slurry was diluted according to manufacturer's instructions, and it was found to contain about 4474 ppm Si and about 3.2 ppm aluminum by graphite furnace atomic absorption. One liter of the waste stream weighed about 998.4 grams. The silicon was present in the waste stream as dissolved and colloidal silica. The waste stream was adjusted to pH 9.84 by addition of small amounts of NaOH and H 2 SO 4 . The waste stream was mixed for about 3 minutes while the pH was adjusted. 2.09 g of a 20% by weight solution of epi-dma, an epichlorohydrin/dimethylamine polymer having an average molecular weight of 250,000±50,000 (EnChem Lot I-1396/423/MIC) was added to one liter of the waste stream and mixed for about 20 minutes.
The reaction mixture was pumped through the filter sock of Example 3 at a pressure of about 6 psi. The filter membrane effluent was collected, and it was found to contain about 8.32 ppm Si and <0.1 ppm aluminum by graphite furnace atomic absorption.
The solids were collected from the filter surface and air dried for 24 hours. The solids formed were well defined spherical particles which were easily removed from the filter membrane surface. The solids appeared dry as they were removed from the membrane. FIGS. 2A and 2 b are scanning electron micrographs of the resulting spherical silica particles. The particles had a typical particle size in the range from 0.05μ to 0.15μ. The dried and ground solids were analyzed, and the results are reported below in weight percent.
KLEBOSOL
Results
Loss on Drying
1.91%
Carbon
1.41%
Nitrogen
0.43%
Silicon
40.49%
Aluminum
0.98%
FIG. 2A is a scanning electron micrograph (SEM) of the resulting spherical silica particles taken at 20,000×magnification. FIG. 2B is a SEM of the product of FIG. 2A taken at 40,000×magnification. EDX analysis of the sample indicated the presence of silicon and aluminum in the sample, wherein the concentration of silicon was much greater than the concentration of aluminum. The silica particles of FIGS. 2A and 2B are remarkably similar to the silica particles of FIGS. 1A and 1B.
Reference is made to FIG. 3 which illustrates one possible wastewater pretreatment system 10 within the scope of the present invention. The illustrated wastewater pretreatment system 10 includes a pluralIty of pretreatment reactor vessels 12 , 14 , and 16 which enable the wastewater feed stream 18 to chemically react with one or more chemical coagulants. Chemical coagulants which react with contaminants in the wastewater feed stream 18 are introduced into the pretreatment reactor vessels via chemical coagulant feed streams 20 , 22 , and 24 . The pH within the pretreatment reactor vessels is preferably monitored with a pH sensor 26 . Acid or base can be added to the pretreatment reactor vessels, if necessary, to adjust the pH via acid/base feed stream 28 .
The number of pretreatment reactor vessels can vary depending on the number of chemical coagulants being used and the reaction chemistry used to form the waste particulates. The size of the reactor vessels can be varied to provide different reaction times.
After flowing through the necessary pretreatment reactor vessels, the wastewater feed stream flows into a feed tank 30 for holding the pretreated wastewater. Additional chemical coagulants can be added directly to the feed tank 30 , if necessary, via a chemical coagulant feed stream 31 . As shown in FIG. 4, the pretreated wastewater is directed to one or more filtration vessels 32 , 34 , and 36 via filtration vessel feed stream 38 . The size of feed stream 38 will depend on the designed flow rate of the filtration vessel. For example, in a system having 5 filtration vessels, each handling 2500 gpm, a 24 inch feed line to the system is suitable. Each filtration vessel 32 , 34 , and 36 is a stand alone filtration device. The number and size of each filtration vessel can vary depending on the system capacity requirements. The filtrate is removed from each filtration vessel via a filtrate stream 40 .
Each filtration vessel preferably provides a mounting platform for from 9 to 49 filter cassette modules. one currently preferred filter cassette module contains 16 individual sock filters configured with 0.5 micron filtration membranes. The rated flow rate is 0.9 gpm per square foot of membrane area. Each full cassette module has 64 square feet of membrane area and is rated at 58 gpm with a differential pressure less than 15 psi. A lifting mechanism is preferably included to allow removal and replacement of the membrane cassette modules.
The filtration membranes are periodically backflushed with filtrate to remove solids from the membrane surface. During the backflush procedure, the filtration vessel is taken off line and wastewater is drained from the filtration vessel via a backflush exit stream 42 to a backflush tank 44 . The backflush tank 44 provides temporary storage before the backflushed wastewater is conveyed to the feed tank 30 via backflush return stream 46 . It is estimated that 400-500 gallons of water will be used during a typical back flush cycle for a 2500 gpm filtration vessel. A vacuum breaker 48 is preferably provided to allow equalization of pressure within the respective filtration vessel 32 , 34 , or 36 during the backflush procedure. A vent/relief stream 49 is provided to allow venting or release of excess or over-pressurized wastewater.
The filtrate side of the filtration vessel 32 , 34 , 36 is open to the atmospheric pressure. The filtrate is collected in the top of the filtration vessel and allowed to drain into the filtrate stream 40 . This volume of water provides the positive head which, when coupled with the negative head of draining the pressure side of the vessel via backflush exit stream 42 , produces enough positive pressure gradient to backflush the filtration membrane.
After sufficient sludge settles within the bottom of the filtration vessel 32 , 34 , 36 , the sludge is removed via a sludge discharge stream 50 . While the sludge is removed, the filtration membranes are preferably rinsed with water from a water rinse stream 52 . The collected sludge is removed from the system for further processing or storage.
Periodically, the membranes may require soaking to remove trace amounts of organics. Cleaning preferably occurs as needed or as part of a regular maintenance program. The vessel drain opens to remove all contaminant via the sludge discharge stream 50 . The cleaning solution is introduced into each filtration vessel through cleaning supply stream 54 . Typical cleaning solutions include acids, bases, and surfactants. In some cases the filtration vessel can be returned to operation without draining and rinsing the filtration membranes. If membrane rinsing is necessary, the contents of the filtration vessel 32 , 34 , 36 are removed via cleaning discharge stream 56 for further processing.
As shown in FIG. 4, multiple filtration vessels are preferably used, in parallel, to provide for the required flow rate. However, the filtration vessels can be operated in series to provide primary filtration and secondary filtration. Because filtration vessels are taken off line during the backflushing, additional filtration vessels and capacity are preferably used to ensure that the require discharge flow is maintained. An additional filtration vessel may be supplied to provide for off-line maintenance while the remainder of the system meets the flow rate requirements.
The wastewater treatment system preferably includes access to the various process streams to allow for sampling and analysis. The valves, pumps, and sensors customarily used in the art to safely control the described fluid flow to and from the filtration vessels are preferably provided. Such valves, pumps, and sensors also allow for automation of the process.
From the foregoing, it will be appreciated that the present invention provides a process for removing contaminants from wastewater utilizing a positive physical barrier to precipitated particles. The positive separation barrier permits discharge having lower concentration limits than conventional clarifier/sand filter systems.
The present invention may be embodied in other specific forms without departing from its essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. | A process and system for removing heavy metals, fluoride, silica and other contaminants from large volumes of wastewater is disclosed. In the process, a wastewater stream containing the contaminant is treated with a chemical coagulant to create a particle having a diameter greater than 5 microns. Treated wastewater is passed through a microfiltration membrane which physically separates the metal contaminant particle from the wastewater. Commercially available microfiltration membranes having a pore size from 0.5 micron to 5 microns may be used. The treated wastewater flow rate through the microfiltration membranes can range from 700 gallons per square foot of membrane per day (“GFD”) to 1500 GFD. Solids are removed from the membrane surface by periodically backflushing the micro-filtration membranes and draining the filtration vessel within which the membranes are located. The dislodged solid material within the filtration vessel is flushed into a holding tank for further processing of the solids. | 1 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to “stack lights”, a visual display used to convey operation and warning information in an industrial environment, and in particular, to a stack light that includes for a modular power converter serving to greatly reduce the number of stocked components needed to provide different stack light configurations.
[0002] Stack lights provide a short tower of different colored lamps, such as may be attached to, or placed in close proximity to, operating industrial equipment to provide a visible indication of the equipment operating status. The tower structure ensures good visibility of the beacon lights over a range of angles and locations in the operating environment. Different colors of the lights allow multiple types of information to be communicated at a distance in a possibly noisy environment. For example, a red light may indicate a machine failure or emergency, a yellow light may indicate a warning such as over-temperature or over-pressure and green may indicate machine operation, etc.
[0003] Stack lights are typically constructed of modular components that may be flexibly interconnected to produce stack lights with different colors, color order and stack heights. Beacon modules, each providing a single color lamp, may be stacked one on top of another, the bottom beacon module supported on a modular base unit.
[0004] Each beacon module includes an electric light source (for example an incandescent or LED assembly) held within a transparent housing, for example a cylindrical tube of colored plastic, through which the light source may be viewed. Upper and lower mechanical connectors on each beacon module allow the beacon modules to be joined into the tower described above. Each beacon module also includes an upper and lower mechanical connector and internal electrical conductors that communicate electrical signals from the bottom of the module to its top. The connectors and conductors operate so that when the beacon modules are assembled together, electrical continuity is established along the height of the tower between the base and the various modules without the need for separate wiring operations.
[0005] As noted the multiple beacon modules are supported on a lower base module. The base module may provide a wire terminal block receiving electrical wiring from an externally switched power source intended to control the lighting of the different beacon modules. The externally switched power source may, for example, be provided by an I/O module or other programmable industrial control unit. Important status information developed during the execution of a control program on the industrial control unit may be relayed to the stack light through the I/O module for display to human operators.
[0006] In normal wiring practices, the base module of the stack light receives a power “common” together with multiple “signal lines” each identified to one of the different beacon modules. A given beacon module is turned on when its corresponding signal line is energized. The electrical continuity as established by the electrical connector and conductor system of the beacon modules, described above, routes each signal line from the base module to a single beacon module input.
[0007] The usefulness and popularity of stack lights has led to a wide variety of configurations of the basic stack light components. As a starting point, the modular components may be offered in different tower diameters (e.g. 30 mm, 40 mm, 50 mm, 60 mm, 70 mm and 100 mm). In each of these diameter classes, a variety of different base modules are normally offered to permit mounting of the tower to different surfaces, for example to a horizontal surface to extend upward therefrom or to the side of a vertical wall or the like. Different base heights are also normally provided as well as different mechanical attachment structures. Also in each diameter class, beacon modules may be offered in different colors (e.g. green, red, amber, blue, clear, and yellow), with different lamp types (LED/incandescent/strobe), different function capabilities (e.g. flashing, rotation) and different power supply requirements (12 V, 24 V, 120 V, 250 volt, AC or DC).
[0008] While modularity of the stack light instruction is intended to provide a customer with the ability to rapidly fabricate a wide variety of different stack light types out of readily available (stocked) components, the large number of component variations can undercut this goal by leading to an impractically large number of different modules. For example, in order to provide the customer with each of the choices described above, with colors, voltages, dimensions etc., many hundreds of different types of pre-manufactured modules may be necessary.
SUMMARY OF THE INVENTION
[0009] The present invention provides a method of reducing the number of stack light modules that need to be stocked without substantially reducing the range of options available to the customer. This is done, paradoxically, by introducing a new module in the form of a modular power converter. The modular power converter optionally fits between the base and the stack of beacon modules to convert operating voltage received at the base to a different backbone voltage.
[0010] The modular power converter operates to reduce component variation in two ways. First, by separating the power conversion function from the base module, a proliferation of different combinations of base modules and operating voltages is avoided, Second, by allowing the power converter to accommodate different operating voltages and convert them to a common backbone voltage, the number of different beacon modules voltages (and beacon modules that can handle those voltages) is correspondingly reduced. Because the customer is largely indifferent to the backbone voltage and is concerned only about the operating voltage supplied to the beacon light, this reduction in stock module count is realized without sacrificing options desired by the customer.
[0011] Specifically, the invention provides a power converter for use in a stack light of the type providing a set of beacon modules interlocking to each other and to a base unit by means of interlocking mechanical connectors and interfitting electrical connectors positioned at a top and bottom of each beacon module and at a top of the base unit, together allowing multiple beacon modules and one base to be mechanically and electrically assembled into a tower with electrical communication between the base and each beacon module. The power converter includes a housing and first and second mechanical connectors positioned at a top and bottom of the housing and adapted to releasably interlock with corresponding mechanical connectors of beacon modules and a base. First and second electrical connectors are also positioned at a top and bottom of the housing and adapted to releasably interface with corresponding electrical connectors of beacon modules and a base. A power conversion circuit is positioned within the housing to receive electrical power from the second electrical connector having a parameter of at least one of voltage and mode to provide converted power to the first electrical connector having a different value of the parameter.
[0012] It is thus a feature of at least one embodiment of the invention to provide a modular power converter separate from the base, which therefore needs not to be reproduced for each different base variation, and yet which reduces the need for manufacturing and stocking each beacon module for many different power types.
[0013] The first and second electrical connectors may be of a same connector type such as would permit inter-engagement of the separated first and second electrical connectors. Similarly, the first and second mechanical connectors may be of a same connector type such as would permit inter-engagement of the separated first and second mechanical connectors.
[0014] It is thus a feature of at least one embodiment of the invention to provide a modular power converter conforming to the order-free connect system of a conventional stack light and so as to permit the power converter to be integrated into an existing stack light system when power conversion is advantageous or omitted from a given stack light system when power conversion is not required.
[0015] The housing may be substantially cylindrical and have a diameter substantially between 30 and 100 mm.
[0016] It is thus a feature of at least one embodiment of the invention to provide a power converter that visually integrates into conventional stack light towers.
[0017] The housing may he substantially opaque.
[0018] It is thus a feature of at least one embodiment of the invention to perform necessary power conversion at a central location rather than as distributed in different beacon modules.
[0019] The housing may he substantially electrically insulating.
[0020] It is thus a feature of at least one embodiment of the invention to provide an insulating bulwark for high voltage operating powers at the power converter.
[0021] The mechanical connectors may be twist lock connectors.
[0022] It is thus a feature of at least one embodiment of the invention to provide a power converter that may be field assembled in the same manner as other stack light components.
[0023] The power conversion circuit may convert alternating current to direct current and/or may provide switched mode voltage conversion.
[0024] It is thus a feature of at least one embodiment of the invention to flexibly and efficiently convert different operating voltages and modes to different backbone voltages and modes.
[0025] In one embodiment, the power conversion circuit may receive electrical power from the second electrical connector having a range of voltages between 12 and 240 V to provide converted power to the first electrical connector having a single voltage.
[0026] It is thus a feature of this one embodiment of the invention to substantially eliminate the need to reproduce beacon modules for different voltages and modes.
[0027] The power conversion circuit may receive signal lines from the second electrical connector and change the voltage on the signal lines before providing the signal lines to the first electrical connector and the power conversion circuit further provides a source of electrical power derived from the signal lines to function circuitry of the power conversion circuit further modulating power on at least one signal line.
[0028] It is thus a feature of at least one embodiment of the invention to permit a power conversion process without the presence of consistent power signal.
[0029] The height of the converter module between the first and second mechanical connectors may be less than two thirds of a height of a beacon module between the first and second mechanical connectors.
[0030] It is thus a feature of at least one embodiment of the invention to provide a power conversion feature in a compact module that does not significantly affect the structure or visual qualities of the stack light.
[0031] These particular features and advantages may apply to only some embodiments falling within the claims and thus do not define the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 is a perspective view of a stack light assembled of several beacon modules, a power-converter/function module and a base module, juxtaposed with alternative unassembled modules;
[0033] FIG. 2 is a fragmentary, exploded, devotional cross-section of the stack light of FIG. 1 showing mechanical and electrical connection of the various modules;
[0034] FIG. 3 is a schematic representation of the circuitry of FIG. 2 showing principal functional blocks of the power-converter/function module including a power converter circuit and modulation function circuit;
[0035] FIG. 4 is a detailed block diagram of the function module of FIG. 3 including a timing state machine and AND-gate modulator;
[0036] FIGS. 5 a and 5 b are timing diagrams of the outputs of the timing state machine of FIG. 4 for two modes of operation in which lamps from different beacon modules are synchronized;
[0037] FIG. 6 is a schematic similar to that of FIG. 3 showing an alternative configuration power converter circuit with direct power supply access;
[0038] FIG. 7 is a perspective view of a stack light embodiment where the terminal block for receiving individual wires is moved to the bottom of the power-converter/function module for easier wiring; and
[0039] FIG. 8 is a cross-sectional view similar to that of FIG. 2 showing a dummy power-converter/function module for providing the benefit of a modularly mounted terminal block when a power converter or function module is not required.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0040] Referring now to FIG. 1 , a stack light 10 constructed according to the present invention may be assembled of multiple interlocking beacon modules 12 a, 12 b, 12 c, a power-converter/function module 14 , and a base module 16 .
[0041] In one embodiment, the lowest most element of the base module 16 may provide a lower flange 19 having one or more openings 20 for receiving machine screws 22 or the like to fasten the flange 19 and hence the base module 16 to a surface 24 of a machine or the like. Alternative base module 16 ′ and 16 ″ may provide for different flanges 19 ′ and 19 ″, respectively, (for example for mounting the vertical surfaces) or for accommodating different base constructions.
[0042] The upper surface of the base module 16 may expose a centered electrical connector 26 (visible in FIG. 1 only on base module 16 ′ and 16 ″) that may be received by a corresponding electrical connector 26 (not visible in FIG. 1 ) on the lower surfaces of each of the beacon modules 12 , power-converter/function module 14 and audio alarm module 18 . Similar connectors 26 exist on the upper surface of each of the other modules, the beacon modules 12 , and power-converter/function module 14 (visible in FIG. 1 only on beacon module 12 ′). Inter-engagement of these electrical connectors 26 in the assembled stack light 10 provide electrical communication between each of the base module 16 , beacon modules 12 , power-converter/function module 14 and audio alarm module 18 as will be described.
[0043] The upper end of the base module 16 also provides a portion of a mechanical interlocking system in the form of radially extending tabs 28 (visible in FIG. 1 only on base module 16 ′ and 16 ″). These radially extending tabs 28 may be received by a second portion of the mechanical interlocking system in the form of twist type bayonet rings 30 rotatably affixed to the lower surfaces of each of the beacon modules 12 and power-converter/function module 14 . Such bayonet rings 30 , as generally understood in the art, provide features on their inner diameter that may capture the radially extending tabs 28 against a helical flange in the manner of inter-engaging threads while providing a slight pocket at the end of the rotation forming a detent that locks the tabs 28 and bayonet rings 30 into predetermined compression.
[0044] Similar radially extending tabs 28 exist at the upper end of each of the other modules: the beacon module 12 , power-converter/function module 14 and audio alarm module 18 (visible in FIG. 1 only on beacon module 12 ′). Inter-engagement of these tabs 28 and bayonet rings of other modules in the assembled stack light 10 permit mechanical interconnection between any of the base modules 16 , the beacon modules 12 , and the power-converter/function modules 14 into the stack light 10 .
[0045] As assembled, the base module 16 , the beacon modules 12 , the power-converter/function module 14 and the audio alarm module 18 provide a tower extending generally upward from the base module 16 through power-converter/function/module 14 , then through one or more beacon modules 12 , each of which may be independently controlled to display a predetermined color illumination.
[0046] As depicted in FIG. 1 , the tower may be capped by a plastic dome 17 also having a bayonet ring 30 but no electrical connector 26 . Alternatively, an audio alarm module 18 operating in a manner similar to that of the beacon modules 12 but providing an audible alarm through sound ports 21 rather than an illuminated signal may replace the final beacon module 12 c. Like the other modules, the audio alarm module 18 may include a bayonet ring 30 on its lower end for attachment to a lower module, and an electrical connector 26 on its lower surface for electrical interconnection to an earlier lower module. Desirably, the audio alarm module 18 may have a dome top without a connector 26 or tabs 28 on its top surface for attachment to later modules, thereby providing a finished appearance to the top of the tower.
[0047] Referring now to FIG. 2 , base module 16 may provide a housing 32 , for example, constructed of electrically insulating and opaque thermoplastic. The housing 32 may provide a cylindrical periphery in diameter generally matching the diameter of corresponding housings of the beacon modules 12 , power-converter/function module 14 and audio alarm module 18 . Standard diameters for stack lights 10 include 30 mm, 40 mm, 50 mm, 60 mm, 70 mm and 100 mm.
[0048] A terminal block 34 may be positioned within the housing 32 of the base module 16 , for example, providing screw terminals, to receive conductors 36 from a remote switching device as will be discussed below. Each of the conductors 36 , when attached to the terminal block 34 , will be routed to the electrical connector 26 a exposed at an upper surface of the base module 16 . This electrical connector 26 a receives a downwardly extending connector 26 b from power-converter/function module 14 when it is connected to base module 16 . Electrical connectors 26 a and 26 b, for example, may he male and female versions of the same connector to be mechanically inter-engageable or may be identical connectors reoriented as in the case of hermaphrodite connector systems.
[0049] For simplicity, the electrical connectors 26 a and 26 b (and all connectors 26 in FIG. 2 ) are depicted with only four conductive inserts 42 (for example, conductive pins or sockets) which may each receive a separate conductor 36 . As is understood in the art. each conductive insert 40 provides an electrically independent conductive path within mating electrical connectors 26 ,
[0050] As noted, the upper edge of the base module 16 provides for radially extending tabs 28 that may be received by a bayonet ring 30 rotatably attached to the bottom of power-converter/function module 14 . In this way the base module 16 may be electrically and mechanically attached to the power-converter/functional module 14 with connectors 26 a and 26 b joined. An O-ring seal 44 may be provided at the junction between the upper surface of base module 16 and the lower surface of power-converter/function module 14 to reduce the ingress of environmental contamination when the two are connected.
[0051] Referring still to FIG. 2 , power-converter/function module 14 may provide for an opaque housing 48 supported at its upper surface connector 26 c being substantially identical to connector 26 a and exposed to receive a connector 26 d when beacon module 12 a is attached to the upper surface of the power-converter/function module 14 . As described above, this connection may be by means of radially extending tabs 28 at the upper edge of power-converter/function module 14 received by a corresponding bayonet ring 30 of beacon module 12 a.
[0052] As will be discussed in greater detail below, power-converter/function module 14 includes power converter/function circuitry 56 that receives electrical power from connector 26 b to convert this electrical power into a backbone voltage for use with the later beacon modules 12 and audio alarm module 18 . In this way beacon modules 12 and audio alarm modules 18 having common voltage parameters (e.g. the same voltage and the same voltage mode of either AC or DC) can be used with stack lights 10 receiving any operating voltage. Power converter/function circuitry 56 further provides for the ability to impose modulation functions such as lamp flashing or module sequencing on the later beacon modules 12 and audio alarm module 18 by modulating the power received by those modules. This eliminates the need for those modules to each include circuitry for modulation functions.
[0053] In various configurations that will be discussed below, the power converter/function circuitry 56 will receive operating electrical power and multiple signal lines through electrical connector 26 b as derived from conductors 36 . From this, the power converter/function circuitry 56 establishes a backbone ground reference on “common” conductor 68 and multiple signal voltages for control of beacon modules 12 or audio alarm module 18 on conductors 75 a - 75 c (typically up to seven conductors although only three are shown for clarity in this example). The common conductor 68 and signal conductors 75 are connected to electrical connector 26 c for example, as depicted in right to left order of signal conductors 75 a, 75 b, 75 c and common conductor 68 .
[0054] Referring still to FIG. 2 , connector 26 d in subsequent beacon module 12 b, may connect to connector 26 c and may be attached, for example, to a printed circuit board 60 carrying on it multiple light emitting diodes (LEDs) 62 . As shown, LEDs 62 are connected between common conductor 68 and signal conductor 75 a occupying the extreme left and right positions of the connector 26 d. Accordingly power on signal conductor 75 a will energize the LEDs 62 of beacon module 12 b so that the light may be viewed through transparent housing 63 . The housing 63 may have a tint to provide a desired light color and/or the LEDs 62 may be selected for a desired color.
[0055] Although the LEDs 62 are shown connected in parallel, series connections are also possible. Current-sharing resistances for each LED 62 have been omitted for clarity.
[0056] The upper edge of the circuit board 60 may communicate with. connector 26 e being identical to connectors 26 c and 26 b. Circuit traces on a printed circuit board 60 provide common conductor 68 joined to an identical location of connectors 26 d and 26 e (in the leftmost position as shown in FIG. 1 ). Signal conductor 75 a used to control the LEDs 62 of beacon module 12 a does not pass to connector 26 e, however, and signal conductors 75 b and 75 c are shifted one connector position to the right so that signal conductor 75 b is now at the rightmost conductive insert 42 of connector 26 e.
[0057] It will be understood then that beacon module 12 h being constructed electrically and mechanically identical to beacon module 12 a may then be attached to beacon module 12 a in the same way that beacon module 12 a was attach the power-converter/function module 14 and that signal conductor 54 b will now be connected to its LEDs 62 .
[0058] The system illustrated for beacon module 12 a and beacon module 12 b may be continued to beacon module 12 c (not depicted in FIG. 2 ) so that signal conductors 75 a, 75 b, and 75 c will control the first, second and third beacon modules 12 according to their order in the stack and in a manner indifferent to the exact beacon module 12 and without the need for adjustment of the internal wiring of the beacon modules 12 a or the setting of internal addresses or the like. The number of conductive inserts 42 in the connector 26 and signal conductors 75 determine the limit of the number of modules 12 that may be stacked in this manner.
[0059] Referring now to FIG. 3 , in a first wiring mode of the stack light 10 , conductors 36 received by the base module 16 do not provide to the base module 16 direct connections to an external power supply 67 that provides the operating voltage of the stack light 10 . This external power supply 67 is normally provided by a customer and may vary in voltage between 12 and 240 V (e.g. 12 V, 24 V, 120 V or 240 V) and may he either AC or DC voltage (termed herein the power supply “mode”). in this wiring mode, the base module 16 receives only a power supply common 52 and multiple switched signal lines 54 a - 54 c representing power from the external power supply 67 only after it has been switched by external switch system 64 . The external switch system 64 may be, for example, relays or a programmable logic controller 110 module referenced through a power supply 67 to the common 52 .
[0060] In this embodiment, the power power-converter/function module 14 taps the signal conductors 54 to obtain power for its operation when at least one signal conductor 54 is active. This may be done by attaching a full wave rectifier 66 between each of the signal conductors 54 and a common DC bus input line 71 . Each full wave rectifier 66 configured to steer either DC or AC current is applied to the signal conductors 54 independently from any of the signal conductors 54 to a filter capacitor 70 referenced to the backbone common conductor 68 while preventing crosstalk between signal conductors 54 .
[0061] The filter capacitor 70 is made, therefore, to provide a source of DC voltage regardless of whether AC or DC voltage is provided by the supply 67 for any time a beacon module 12 is to be activated. The effective filter time constant provided by capacitor 70 is chosen to prevent the imposition of any meaningful delay in the generation of necessary power once a signal is present on any one of the signal conductors 54 . Nevertheless, voltage of the power on capacitor 70 will vary substantially according to the operating voltage of the power supply 67 . Accordingly, the voltage on the capacitor 70 may then be provided to a voltage regulator 72 uniformly converting that voltage to a least common denominator voltage (e.g. 12 VDC) of local backbone power conductor 74 . The voltage regulator 72 may be of any design including, for example, a switched mode regulator well known in the art. By using a boost mode converter, the voltage of the local backbone power conductor 74 may be, in fact, higher than 12 V by allowing 12 V power supply voltages of power supply 67 to be boosted appropriately.
[0062] The backbone power conductor 74 and backbone common conductor 68 provide power to the modulation function circuit 58 as will be described below and define the voltage level of the active signal conductors 75 connecting to the beacon modules 12 .
[0063] As well as scavenging power from the signal conductors 54 , the power-converter/function module 14 also extracts the information content on the signal conductors 54 by passing them through optoisolators 78 (one for each conductor 54 ) which isolate the operating voltage of power supply 67 (in common 52 ) from the backbone power conductor 74 (and backbone common conductor 68 ) and optically isolated electrical signals 80 a, 80 b, and 80 c (each corresponding to one of conductors 54 a. 54 b and 54 c respectively) are then provided to the modulation function circuit 58 which may modulate those signals when present according to a desired pattern set by a user, for example, through a dip switch 82 providing signals to modulation function circuit 58 .
[0064] Referring now momentarily to FIG. 4 , modulation function circuit 58 may be implemented in a variety of different ways including a microcontroller, programmable gate array or discrete logical circuitry and generally includes a modulation clock 84 , for example, providing a base modulation frequency. The modulation clock 84 may, for example, be a conventional RC oscillator and divider circuit to provide a modulation frequency of 1 Hz. The output of the modulation clock is then received by programmable timing state machine 86 whose particular programming (and hence the modulation pattern) is set by switches 82 . In one example, three outputs 85 a, 85 b, and 85 c from the timing state machine 86 (for example, such as may control the modulation of signals to beacon modules 12 a, 12 b, and 12 e ) may provide identical square waves at the frequency of the clock 84 . Each of these outputs may be received by an AND gate 88 whose other input is one of the signals 80 a - 80 c output from the optoisolators 78 indicating the state of activation of the signal conductors 54 . This modulation pattern would provide synchronized flashing of any active beacon modules 12 . In this case, the modulation pattern would be synchronized and identical among beacon modules 12 .
[0065] Another modulation provided by switches 82 may provide for steady high state output on each of the four signals 80 a - 80 c of the timing state machine 86 essentially providing no function blinking of the beacon modules 12 when they are activated. It will be understood that some settings of the switches 82 may likewise provide modulation on only some of the signals 80 a - 80 c so that selected beacons may be modulated and other beacons not modulated. Different modulation patterns (for example frequencies) may be applied to different of the signals 80 a - 80 e.
[0066] Alternatively as shown in FIG. 5 a, the output signals 80 a - 80 c of the timing state machine 86 may alternately turn high in a round-robin “marquee” pattern so that when multiple beacon modules 12 are activated their illumination expresses an animation, for example, of an upwardly rising single point of illumination that passes successively through each colored beacon.
[0067] In contrast, as shown in FIG. 5 b, a “stacked” pattern may be implemented in which, for example, an upwardly rising animation is generated but with the lowermost beacon remaining on as successively higher beacons are illuminated until all are ultimately illuminated and then extinguished together and this pattern repeated.
[0068] In all of these examples, the flashing of different beacon modules 12 is synchronized in a way that is difficult when the timing circuitry for flashing is localized in the individual beacons themselves. This latter modulation provides modulation patterns that are also synchronized but are not identical. Another similar synchronized but different set of modulation patterns might provide different frequencies for each beacon module 12 but are nevertheless phase synchronized.
[0069] Referring now to FIG. 6 , it will he appreciated that the present invention may also work with a dedicated power supply line 90 from the external power supply 67 for example, introduced through a separate screw terminal so that the base module 16 has direct access to constant electrical power through power supply common 52 and power supply line 90 . In this case, power may be directed from this power supply line to a single full wave rectifier 66 providing current to capacitor 70 .
[0070] Referring now to FIG. 7 , in an alternative embodiment, the terminal block 34 may be moved from the base 16 to the bottom surface of the power-converter/function module 14 . This allows more convenient wiring, for example, when the base 16 is mounted in an elevated location, by allowing an extra lanes of the conductors 36 to be threaded through the base 16 and downward to the inverted power-converter/function module 14 so that the conductors 36 may be attached to the terminal block 34 when the terminal block 34 is upward in a less awkward orientation. This same benefit can be provided when the features of a power-converter/function module 14 are not required, as shown in FIG. 8 , by the use of a dummy power-converter/function module 14 in which the terminal block 34 is connected directly to the connector 26 b by traces on printed circuit board 60 .
[0071] It will be appreciated that the LEDs 62 may be replaced with incandescent lamps according to well-understood techniques.
[0072] Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, “bottom” and “side”, describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context.
[0073] When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
[0074] It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein and the claims should be understood to include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. All of the publications described herein, including patents and non-patent publications, are hereby incorporated herein by reference in their entireties.
[0075] It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein and the claims should be understood to include modified forms of those embodiments, including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. | A power converter is introduced into a stack light in the form of a compatible modular element that fits between the base and a light module. By converting multiple input voltages to a common core voltage in a module distinct from the base and light modules, proliferation of different varieties of base modules and light modules may be reduced without impact on customer selection. | 5 |
FIELD OF THE INVENTION
The present invention is concerned with improvements in or relating to methods of mass spectrometry and also in or relating to apparatus therefor. More particularly the invention is concerned with methods and apparatus for sensitive, broad band mass spectrometry, whereby a relatively wide range of ionic masses can be examined simultaneously to a high degree of sensitivity.
REVIEW OF THE PRIOR ART
There is a continuing need for methods and apparatus for ultra-sensitive examination and analysis of materials, i.e. so as to be able to detect impurities of less than one part per billion (10 -9 ) to examine samples of micron size. As a specific example of the application of apparatus of this sensitivity, it can be used for the examination of the silicon or gallium arsenide used for the manufacture of solid state devices, since if this includes radioactive impurities of this order of magnitude there is the possibility of the internal generation of spurious "bits" by discharge of a particle, causing operation errors in the apparatus in which it is incorporated.
Another field of application is the dating of materials by carbon 14 or chlorine 36 measurements. The established techniques depend upon the sensing and counting of particles emitted by the radioactive isotope to determine its relative abundance in the sample, or by the sequential measurement of isotopic abundance directly by sensitive mass analysis. The determination could be conducted very much more quickly with greater accuracy and with much smaller samples of material by the simultaneous measurement of isotopes.
Severe problems also arise in the examination for mass analysis of extremely small samples, since the act of examining the sample by an ion "micro-probe" can change significantly the constitution of the sample. Unless therefore a simultaneous "one-step" determination can be made of all of the components from a single scan by the probe it may not be possible to repeat the examination at all, or at least without significant error. Many analysts also require the examination of extremely small areas of a large sample, i.e. of the order of a square micron, in order to analyse a small inclusion therein. Scanning of this order is feasible but the subsequent analysis requires a high order of sensitivity and simultaneous maximum isotopic information if useful results are to be obtained.
It is well recognized in the art that broad band capability is highly desirable in a mass spectrometer, but this has been difficult to achieve, since the magnetic systems employed are inherently narrow band mass-selective, making the design of a broad-band system able to measure accurately in a greater range of masses complex and expensive.
There has been described in U.S. Pat. No. 4,037,100, issued July 19, 1977 to General Ionex Corporation an ultra-sensitive spectrometer for making mass and elemental analyses. The apparatus requires a source of negative ions produced as a beam thereof which is mass analysed by passing it through a mass analysis magnet. The selected portion of the mass analysed beam is then passed to a molecular dissociator, such as a tandem accelerator, in which molecules in the beam are dissociated by coulomb disruption and the ions undergo charge exchange to issue therefrom as a high energy beam of positively charged ions. The beam is then magnetically deflected and directed into an energy sensitive detector calibrated to provide an output signal proportional to the energy of the detected particles. Such apparatus is essentially narrow band in operation.
The magnetic devices that are required for the rigid high momentum high-energy beams are complex and expensive if ions of high mass are to be measured effectively, and the selectivity falls off rapidly with increasing mass. The use of multiple detectors spatially distributed from one another and each detecting a different range of masses results in even greater complexity and expense.
DEFINITION OF THE INVENTION
There is therefore a need for an analysis facility which can determine:
(a) Isotopic and elemental abundances of any element in very small (picogram to milligram) quantities of material.
(b) the spatial variations of a broad band of isotopic and elemental abundances on the surfaces of material with point to point resolutions as low as 1 micron, and simultaneous determination of all relevant mass at each point.
(c) Isotopic and elemental concentration levels in ranges lower than the currently accepted limits, namely in levels less than 1 part in 10 9 .
It is the principal object of the invention to provide a new mass spectrometer of such broad band capability and high sensitivity, even with ionic masses in the upper range of the elemental values.
In acordance with the invention there is provided a method of high-energy, broad-band, charge-changing mass spectrometry:
(a) producing a continuous quantity of negatively charged atomic ions of mass band and abundance to be determined, which quantity will also include unwanted molecular ions,
(b) passing the said continuous quantity of negative ions through at least one electrostatic device which is charge sensitive in accordance with the ratio E/q where E is the ion energy and q is the ion charge, whereby the device will select ions of wanted ratio and reject ions and molecules of unwanted ratio, so that the device receives the said quantity of negative ions and selects therefrom the ions of wanted ratio and rejects the ions of unwanted ratio,
(c) passing the selected ions from the electrostatic device of (b) to an accelerating, molecular destruction and charge-changing device in which the selected ions are accelerated to result in higher energy ions of energy sufficient to permit the passage of these higher energy ions through the accelerating and charge-changing device with molecular destruction and change of charge to result in a beam of multiply-charged positive ions including molecular fragments, and
(d) passing the said beam of multiply-charged positive ions and molecular fragments to a continuous operation electrostatic time-of-flight mass analysis system that is isochronous for ions of the same mass, the system comprising a start detector and a cooperating stop detector through which the received beam passes for operation of the system,
(e) the start detector comprising a thin foil through which the received beam passes resulting in an output beam therefrom of ions of altered charge state and consequent changed E/q ratios,
(f) the mass analysis system comprising at least one system electrostatic device which is charge sensitive in accordance with the said ratio E/q for selection of positive ions of wanted ratio and rejection of ions of unwanted ratio, the device receiving the beam passing through the system, selecting the positive ions of wanted ratio and rejecting the ions of unwanted ratio.
In another method of the invention the ion source produces positive ions and the positive ions are passed through a charge changing device to produce a corresponding quantity of negative ions that are then passed to the accelerating and charge changing device.
The invention also embraces apparatus for carrying out the methods of the invention.
DESCRIPTION OF THE DRAWINGS
Methods and apparatus that are particular preferred embodiments of the invention will now be described, by way of example, with reference to the accompanying schematic drawings wherein:
FIG. 1 illustrates a first embodiment incorporating an all-electrostatic means for selecting the range of ionic masses to be examined,
FIG. 2 illustrates a second embodiment comprising a different configuration of time-of-flight mass spectrometer from that of FIG. 1, the portion of the apparatus preceding the time-of-flight spectrometer being the same, and
FIG. 3 shows an alternative magnetic form of negative ion selector if maximum broad band operation is not required.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The apparatus conveniently is considered as divided into three major successive portions, namely a first portion 10 in which the ions to be examined are prepared in the form of a low energy beam and subjected in a selector to a preliminary broad-band analysis, a second or middle portion 12 in which the prepared beam of ions is subjected to molecular disintegration and charge exchange to result in a high energy beam of positive ions, and a third or final portion 14 comprising an isochronous electrostatic mass spectrometer in which the final sensitive analysis is carried out.
In this first embodiment the first portion 10 comprises a source 16 of negative ions, the particular source producing negative secondary ions as the result of scanning a sample 18 with a beam 19 of positive ions produced by a source 20 thereof under the control of a scanning circuit 22 which rasters the beam over the sample. For example the positive ion source can be a liquid metal hydrodynamic source in which the ions are produced by high gradient electric fields, or a gas discharge source such as a Penning ion source, or a thermal ionisation source employing cesium or gallium. Such sources are available in which the scanning beam has a cross-sectional area of about 1 micron square or less. The impingement and scanning of such a beam generates a shower predominantly of secondary negatively-charged ions that constitutes a simultaneous assay of all the atoms in the scanned area and can therefore include ions of a wide range of masses. Inevitably it will also include molecular ions of the same charge and stray molecular and atomic ions of opposite charge, the unwanted ions and molecules constituting an unwanted interfering background. At the usual energies employed in mass spectrographs of a few tens of kilovolts such molecules persist even after they have passed through regions of high gas pressure.
Scanning beams of this kind can be produced with a low energy spread to give beam current of about one microampere, and can be focussed to less than 1 micron diameter because of the low energy spread which corresponds to chromatic aberration. The secondary ion beam must be injected into the molecular disintegrator and charge changer of the middle section without substantial mass discrimination if the objective is to be achieved, and to this end the ion selector system is a broad band electrostatic mass spectrometer comprising two spaced spherical electrostatic analyser lenses 24 and 26. Such lenses are mass insensitive, but instead are charge sensitive in accordance with the relation E/q where E is the ion energy and q is the ion charge.
The first deflecting lens 24 ensures as far as possible that the ions originate at the ion source and that they have suffered no molecular break-up or charge changing collisions, while the second lens focusses the ions on the input to the molecular disintegrator so as to inject the negative ion beams therein at the relatively small target presented by its charge changing canal; this lens will also assist in eliminating from the beam any unwanted doubly-charged ions and/or ions of wrong energy.
In some analyses it is preferred to be able to examine the sample with a negative primary ion probe, which will result in a shower of positive secondary ions (plus the corresponding contaminants). It is more efficient to produce some negative ions by the charge changing of positive ions than by direct sputtering, and this is especially true for the group III elements such as Al and the group II elements such as Be which form more abundant metastable negative ions. Since the production of negative ions by charge changing is a multistep process, the yield of metastable ions can also be expected to be higher than by direct sputtering. This option is readily provided by including a charge-changing device 28 between the two lenses 24 and 26 at their mutual stigmatic focus. This is also an appropriate location for an intensity reducing device, such as a chopper, to prevent overloading of the subsequent portions of the apparatus. There may also be provided at this location a suitable slit to select the ion energy with greater resolution. An example of such a negative ion probe is an intense beam of oxygen or halogen ions. The charge-changer is for example a canal containing a metal vapour, typically sodium, maintained at about (20+W) KV inside the canal where -W is the voltage (negative) of the canal. Collisions in the canal will result in some molecular dissociations and the resulting fragments will be rejected by lens 26, so that a "cleaner" beam results. The lens 26 focuses the ion beam to a "point" which forms the object for the entrance lens of the molecular disintegrator 30.
The function of the device 30 is to accelerate the negative ions to a relatively high potential, e.g. about 3 MV, and then pass them through a gas-containing charge-changing canal from which they emerge as energetic positive ions. Under these conditions sufficient outer electrons are stripped from any molecules present in the beam to ensure their disintegration as described below. The operation of such a disintegrator or dissociator is also described in the above-mentioned U.S. Pat. No. 4,037,100, the disclosure of which is incorporated herein by reference.
One of the most serious problems of conventional mass spectrometry is the limitation of sensitivity in elemental analysis by the interference of molecular ions of almost the same mass. An efficient way to eliminate the molecular interference is to use the fact that removing three or more electrons from the molecules causes them to break up rapidly. This complete molecular destruction is achieved by accelerating the negative ions in a tandem accelerator to about 1-3 MeV at the tandem terminal where they are stripped of a few electrons by colliding with argon gas atoms in a charge changing canal. The terminal voltage of about +1 to +3MV is chosen to maximize the yield of charge state +3 for light atoms, since it is known in the art that at least three electrons must be removed to ensure the destruction of molecules. Other charge states (Q) will also be produced in these equilibrium charge changing collisions. The positive ions emerging from the positive terminal will be further accelerated by the electric field from the terminal voltage down to ground potential. For charge state Q=+3 and terminal voltage +3MV the energy of the ions is about 12 MeV and one of the advantages of using these energetic ions is that nuclear particle detectors can be used to detect and identify them. The normal range of energies of these particles is about 8-20MeV and for massive particles (i.e. M>100) of these energies magnetic lenses would be complex and expensive.
The beam of positive ions emerging from the charge changer 30 passes through a further electrostatic analyser lens 32 which will reduce the quantity of the molecular fragments produced therein, so that they are not passed to the mass spectrometer portion 14. For useful experimental results the beam of ions must be analysed as to mass (M), energy (E), and charge (q). As is known and described above the electrostatic analyser lenses used so far are only able to discriminate as to ratios of E/q, and in most cases it is preferred that there be no discrimination on the basis of mass. The mass determination is therefore effected in the final portion of the apparatus using a time of flight mass spectrometer that is isochronous as to the time of flight for ions of the same mass and with the energy spread accepted by the apparatus (usually ±0.5%). In a typical system up to about 1 million ions per minute are emitted by the disintegrator 30, giving an average time interval between successive particles of 60 microseconds. The transit time through the isochronous spectrometer will be of the order of 200 nano-seconds per meter of flight path, which is therefore sufficiently smaller than the above-mentioned time interval for the apparatus to be operated continuously without the need for pulsed operation, and with minimum dead time, to obtain the necessary mass discrimination. Such continuous operation is preferred with apparatus of the invention. A more compact and optimum configuration can be achieved by use of pairs of electrostatic analyser triplet lenses of alternating electrostatic gradient sector type, with corresponding shorter drift spaces between each pair. For a general discussion of electrostatic lenses and their design reference may be made to "Focusing of charged particles" edited by Albert Septier and published 1967 by the Academic Press Inc. New York, N.Y.
The stream of high energy ionised particles issuing from the disintegrator 30 pass through a first drift space 34 to a start detector constituted by the combination of a thin carbon film 36 and a secondary electron detector 38. Thus, the passage of a particle through the film causes ejection of secondary electrons that are transferred to the detector 38 by a weak electron lens, the resultant electric signal being fed to a suitable measuring/recording device, such as a cathode ray oscilloscope 40, or time-to-amplitude converter. The particle beam continues through a second drift space 42 and enters the first one of a pair of symmetric spherical electrostatic analysers 44 and 46, the analyser 44 being disposed with the start detector at its object plane. In this embodiment the analysers are designed to deflect the path of the particle beam through 43.42° and they are spaced apart a specific distance described below to provide an intervening drift space 48. These analysers produce deviations of the particle beam of equal amounts in the same sense and with a common focal plane 50 in the space 48, so that the system is symmetrical about the plane 50. The particle stream emerging from the second analyser 46 passes through a final drift space 52 and enters a total energy absorber and stop detector 54 disposed at the object plane of the analyser 46 and producing an electric signal that is also fed to the measuring device 40, this signal therefore being representative of the energy of the received ion as well as giving its arrival time for transit time determination.
The passage of the highly energetic positive ions through the carbon film 36 is unavoidably accompanied by energy straggling, small energy scattering and charge changing collisions producing an energy spread and a small angular divergence between the particles of the beam. This energy spread and divergence reduces the accuracy of measurement in a time-of-flight detector when used for unit mass resolution to the extent that resolution is difficult for atomic masses below 100 and impossible for masses above 100. For example it can be shown that the percentage energy difference (ΔE/E) between 194 Pt +5 the ion produced from PtH is about 0.08%, whereas the energy spread through a carbon film of 2 μg/cm 2 thickness is 80 KeV for ion accelerating potentials of 18 MeV, corresponding to a ΔE/E of about 0.44%. Attempts to increase the resolution of the apparatus by increasing the length of the flight path and consequently the intrinsic time of flight resolution is ineffective, since the said percentage energy difference is so heavily swamped by the energy spread through the film. Moreover, in practice as described below it is preferred to decrease the size of the equipment as much as possible and not increase it. A further cause of error is that some of the "rays" constituting the particle beam impinging on the film are inclined "off-axis".
Other small energy variations are introduced into the particle beam by, for example:
(1) Variation in ion accelerating potential,
(2) Multiple charge exchange and acceleration,
(3) Breakup of molecules, in particular of hydrides.
These other variations are either compensated for by the apparatus to be described or the unwanted particles are rejected from the beam.
The effects of the energy variations produced by the start signal fail are compensated by arranging for the flight path through the apparatus to be isochronous for particles of the same mass. This is possible if the ion flight path is proportional to the square root of the energy spread according to the relation ##EQU1## where L o is the length of the trajectory for the primary ion, i.e. the ion of original velocity before the effect of the spread. The more energetic ions will follow longer paths, while the less energetic will follow shorter paths, the transport time along any of the trajectories depending only on the ion mass. The time of flight and hence the mass resolution will be limited due to this finite energy spread introduced by the thin carbon foil and typically a mass resolution of 0.5% can be expected for a foil thickness of 2 μg/cm 2 . The effect of this finite energy spread can be removed by an appropriate choice of the electric analyzers 44 and 46 (or their equivalent) and the connecting drift spaces so that the ion trajectories from start to stop detector are essentially made isochronous for ions of the same mass. Although a number of configurations are possible, for transport to be isochronous, those consisting of two electric analyzers with radial focusing are constrained by the condition: ##EQU2## where L is the drift space length, r is the radius of curvature, θ is the bending angle and p is the field index for the electrostatic analyzer. A practical configuration is given by:
L-1.88 meters
θ=43.24°
r=0.75 meter
p=1.
The configurations of lens elements described permits the isochronous transport of all ions from the object plane of the first lens element to the image plane of the second lens element. With the system symmetric about the stigmatic focus plane 50 the isochronous transport is able to compensate for the angular divergence of the ions that is also introduced by the foil 36 to the first order. Lenses of other deviation will require other factors as will be apparent to those skilled in the art.
Although in one preferred embodiment spherical electrostatic analysers producing a deviation of 43.42° are employed, such devices of sufficient size for a beam of satisfactory energy and envelope dimensions tend to be large and costly, the drift spaces on either side of each analyser being of the order of 1.88 meters for analysers of 0.75 meter radii of curvature. In a less expensive construction also illustrated by FIG. 1 the spherical analysers 44 and 46 are replaced by two cylindrical analysers providing approximately the same angle of deviation and two focusing elements 56 and 58 such as electrostatic quadrupoles are disposed respectively in the drift spaces 42 and 52.
In another embodiment illustrated by FIG. 2, the spherical electrostatic analysers of FIG. 1 are replaced by two symmetric cylindrical lenses 60 and 62 with an interposed singlet defocusing quadrupole lens 64 in the drift space 48 at the stigmatic focus plane 50. In this second embodiment the deviation produced by the elements 60 and 62 is approximately 45°.
In a fourth embodiment illustrated in part by FIG. 1 the spherical electrostatic analysers of part 14 are replaced by a triplet of electrostatic analysers such that the first and last elements of the triplet have equal electric field gradients and bending angle, but gradients of opposite sign to that of the central member of the triplet. The magnitudes of gradients and the bending angles of the triplet elements are chosen to reduce the length of the drift spaces between each triplet. This length reduction is possible for electric gradients of greater than 2, for which the time compensation of this analyser segment requires the same sign as that for a drift space with a corresponding stronger time compensation.
The underlying principle is that the transit time for an ion which has lost or gained energy can be adjusted to be equal for all ions of the same mass, if an appropriately shorter or longer trajectory is chosen. In general the flight path length through a sector field increases in response to an increase in ion energy. As the opposite is true for drift spaces, a suitable combination of sector fields and drift spaces can always be found to produce isochronous trajectories.
The count rate of the apparatus described is limited essentially by the maximum time of transit between start and stop detectors for the mass band under consideration. This is because one has to make sure that during the time of flight of an ion no other ion will enter the detectors to give a false start or stop signal. For masses equal to or less than 232 atomic mass units (amu), E=15 MeV and flight path of 3 meters the maximum time of flight should be about 1 microsecond, implying a maximum count rate for the isochronator of about 100 kHz (allowing for a 10% efficiency of charge state transmission from the start timing foil to the stop detector). Because of the limitation of the count rate it will be preferred to restrict the width of the mass band under analysis, and in particular to eliminate the copious amount of light ions which usually are not of interest. One way to accomplish this is by appropriate selection of the charge state using lens 24 and 26 or their equivalents. For instance, the choice of Q greater than +11 for 15 MeV ions can be made to effectively eliminate almost all the light ions, since they will not have the correct E/q values to pass through the Isochronator.
With the above-described start detector using secondary electrons emitted by the passage of an ion through a thin foil, the secondary electrons can at present be detected at best with approximately 100 picoseconds resolution. The stop detector 54 can be similar to the start detector or, for example, a surface barrier or gas ionisation detector which can give good timing (about 100-400 picoseconds) and energy signals. It is clear that with care one can get an overall timing resolution of better than Δt=400 picoseconds. The mass spectrum of the examining beam is obtained with the usual timing amplifiers, constant fraction discriminators and time-to-amplitude converters.
For a conventional time-of-flight the mass (M) is related to the non relativistic energy (E), flight time (t) and flight path (1) as follows:
M=2Et.sup.2 /1.sup.2 (3)
wherein two successive isochronous path particle receiving means 14 are provided and wherein the inclinations of the two means are opposite and equal with the object plane of one coincident with the image plane of the other. Such an arrangement is also isochronous in space, that is to say "off-axis" rays of the particle beam are also rendered isochronous.
In many applications of the invention the maximum broad band capability of the first described embodiment may not be necessary, for example when a somewhat restricted range of masses is to be examined, and in this case the embodiment of FIG. 3 may be employed, wherein at least the ion producer is of magnetic type and not electrostatic. The system comprises two pairs of magnetic lenses 66 and 68 replacing the electrostatic devices 24 and 26 of FIG. 1 and symmetrically disposed about a plane 70 in which the ions of different masses are dispersed because of the mass sensitivity of the lenses. The system need only be of relatively low overall resolution (approx. 10%), since the final resolution is accomplished in the ion receiving portion comprising the line-of-flight mass spectrometer. Any mass discrimination required is readily provided at the plane 70 by means of a suitably shaped aperture, and this system does provide the facility of eliminating substantially completely ions of any unwanted ranges of mass, such as those of the lighter elements and also the heavier unwanted molecules and molecular fragments which may not be entirely eliminated in the system of FIG. 1. This system therefore has the advantage of producing a "cleaner" beam of ions. It also permits the use of higher ion currents in the selected mass range and results in higher sensitivity. A charge change canal device 28 is provided if required.
Low detection limits (greater than one part in 10 12 ) and high sensitivity (efficiencies of greater than 1%) are the principal requirements for the detection and measurement of most radioisotopes at natural abundances or the search for rare particles of unknown mass. In the search for these particles using prior art broad band mass spectrometry at least one or more ion beams formed by the abundant stable isotope must be selectively removed or attenuated by at least 9 to 12 orders of magnitude to prevent damage to the heavy ion detectors due to an excessive counting rate. The medium band magnetic systems of this invention which accept a band of masses (ΔM=0.1 M) would therefore be appropriate for these searches as specific masses within that band can be attenuated or removed. On the other hand, as described above the typical ion microprobe examination requires low sample consumption (modification) rates, which dictates the use of low current primary scanning beams, and hence low secondary ion intensities can be anticipated, and the mass independent all electric systems of the invention are more suitable in this case. | A highly sensitive broad band mass spectrometer consists of a broad band selector of a low energy level beam of negative ions to be examined; a molecular disintegrator and charge changer which receives the negative ions and produces a beam of high-energy multiply charged positive ions free of molecules; and a broad band high-energy, continuously-operable isochronous time-of-flight mass spectrometer which receives the output from the molecular disintegrator. The disintegrator destroys molecules that would obscure the measurement of atomic species. Both selector and spectrometer preferably are electrostatic to avoid mass discrimination and maintain the broad band capability. The use of an isochronous time-of-flight mass spectrometer permits continuous operation which increases sensitivity. The ion selector may be of a magnetic type if a somewhat narrower band of masses is acceptable. | 7 |
FIELD OF THE INVENTION
The invention disclosed herein is directed to the field of paper machine clothings.
BACKGROUND OF THE INVENTION
Paper machine clothing is the term for industrial fabrics used on paper machines in the forming, pressing and drying sections. They are generally fabricated with either polyester or polyamide multifilaments and/or monofilaments woven on conventional, large textile looms. These fabrics have been fabricated by conventional weaving techniques. The materials and processes, although an industry standard, have some inherent limitations described below.
The primary function of all paper machine clothing (PMC) is removal of water from the paper sheet. As both the manufacturer of paper machine builder and papermaker work to increase the speed of the papermaking process and improve paper quality, new barriers have been identified for PMC fabrics that demand innovation in materials and fabric design. Furthermore, the PMC manufacturer is also looking for more efficient production of PMC fabrics and enhancing key quality characteristics of the same.
Today, paper making machines are attaining such rapid speeds that the thickness of the fabric structure is beginning to limit the rate of water removal, especially in the forming section. Insufficient dewatering results in low sheet strength. Sheet strength is critical for transferring and maintaining sheet properties through the next, more aggressive stages of sheet dewatering. One possible solution is to lengthen the forming section of the machine, but this is rather expensive and therefore of limited viability. The other approach is for the PMC manufacturer to produce thinner fabrics, but in a weaving process the smallest possible dimensions are the combined diameters of the filaments used in the warp and shute directions. Criteria such as dimensional stability, fabric strength and fabric life result in a practical limit to the fineness of the filament diameter and thus the overall thickness of the fabric. In many PMC positions, a tradeoff of these properties is not feasible or practical, and in fact higher machine speeds actually require further enhancement of these properties.
PMC fabrics are also porous media that must effectively achieve fluid flow, that is, either water flow in forming and pressing or air flow in drying. The porosity of the fabrics can greatly affect sheet properties important in the forming and pressing sections of the paper machine. Channels for transport are formed by the open spaces or interstices, between the warp and shute yarns. Channels also exist between the filaments at the crossover points. The weaving process limits the geometry of the pores because the yarn filaments are orthogonal.
The surface topography of PMC fabrics contributes to the quality of the paper product. Efforts have been made to create a smoother contact surface with the paper sheet. However, surface smoothness of PMC woven fabrics is limited by the topography resulting from the weave pattern and the filament physical properties. In a woven fabric (or knitted fabric), smoothness is inherently limited by the knuckles formed at the cross-over point of intersecting yarns.
PMC fabrics require constant cleaning because of build-up materials from the paper furnish. Two mechanisms of fabric soiling have been identified. Mechanical bonding occurs when fine particles from the paper furnish are entrapped in the spaces existing between filaments in the fabric. This mechanical bonding is enhanced by the fine interstices created at the orthogonal cross over points in a woven fabric. Chemical bonding describes the adherence of fine particles that comprise the furnish to the fabric due to the existence of chemical affinities. This problem has been studied over many years of effort and results indicate that mechanical bonding is more important than chemical bonding overall. Decreasing permeability from particle build-up decreases the useful life of a fabric. High pressure showers have been employed to wash the fabrics, but the harsh abrasive environment these showers present also decreases the useful life of PMC fabrics.
PMC manufacturing technology could be improved by speeding the weaving process. In weaving, a warp is threaded through a heddle, and the weave pattern is created by raising and lowering the heddle position for each filament in the warp direction before the shute pick. This is a slow process due to its many steps. A practical production rate for typical forming, pressing or dryer loom is limited to 100 picks/minute.
A variety of forming fabrics based largely upon polyester monofilaments have been developed in the past few decades. The most advanced of these developments is a two-layer monofilament fabric in which the two fabric layers are held together via a binder monofilament. Commercially, this fabric is sold under the name Triotex® by Albany International Corp., Albany, N.Y. The binder monofilament is the only monofilament in the Triotex® structure that holds the two fabric layers together. The top fabric layer is usually a plain weave structure, which is designed for optimal paper sheet formation. The bottom fabric layer is designed for wear and typically has long floats in which the shute monofilament travels under three or more warp monofilaments. These long floats are used as an abrasive wear surface, which wears away before wear can occur to the warp monofilaments. The binder monofilament is a shute monofilament that mechanically holds the top and bottom fabric layers together by traveling over a warp monofilament in the top fabric layer and under a warp monofilament in the bottom fabric layer. Under running conditions, the bottom and top fabric layers move relative to each other. This relative movement leads to fatigue and wear of the binder monofilament due to repeated deflection back and forth within the structure. Eventually, the binder monofilament will fail and allow the top and bottom fabrics to separate from each other. This separation leads to product failure.
PMC press fabrics are constructed from woven base fabrics of monofilaments and multifilaments. A carded web of staple filaments is needled onto the base fabric, forming a construction capable of transporting water away from the forming sheet of paper. Needling can damage the monofilaments in the base fabric, weakening the fabric. Press fabrics are also prone to shedding, the release of the batt fibers from the felt. Shedding results in a contaminated paper sheet and shortens the useful life of the press fabric. Paper sheet rewetting is often a problem in press fabrics. Fluid removed from the sheet in the press nip can return to the sheet immediately after exiting the nip, reducing the overall efficiency of the pressing operation.
U.S. Pat. No. 4,740,409 discloses a nonwoven fabric having knuckle-free planar surfaces comprised of parallel linear machine direction yarns residing in a single plane and interconnecting, cross-machine direction polymeric material also residing in the plain, the cross machine direction material entirely surrounding the machine direction yarns. An array of side by side sheath core yarns are fed to machine direction grooves of a pinned roll section where they are forced into the grooves by heat and pressure. The sheath core monofilament cross section area is greater than the area of the machine direction groove so that excess sheath material is forced into cross direction grooves to form the cross directional interconnecting structure.
U.S. Pat. No. 5,077,116 discloses a forming fabric having a non-woven surface coating. The forming fabrics have a transverse nonwoven sheet contact layer adhered to the base fabric layer. The fluid flow passageways between adjacent structured members in the nonwoven sheet contact layer are smaller than the fluid flow passageways in the adjacent base fabric layer and are in fluid communication with the nonwoven sheet contact surface or the nonwoven surface adjacent the base fabric, or both. The nonwoven sheet contact layer may be comprised of bicomponent fibers having a polyester core and low melting temperature copolyester sheath. It is disclosed that these fibers could be adhered to each other and to the base fabric by fusion bonding means.
U.S. Pat. No. 5,366,797 discloses a bonded yarn bundle comprising at least one twisted multifilament yarn composed of a first synthetic polymer, whose individual filaments have become bonded together over essentially the entire thread cross-section by the melting of a second thermoplastic synthetic polymer whose melting point is at least 10° C. below the melting or decomposition point of the first synthetic polymer.
The yarn bundles comprised of a yarn of a first synthetic polymer is a meltable or nonmeltable polymer which provides a high strength characteristic. The yarn of a second synthetic polymer is a meltable material whose melting point is lower than the melting point of the first material.
GB 2 097 435 discloses a papermaker's fabric using yarns woven from high melting point monofilament or multifilament warp yarns and similar top and bottom weft yarns. Stiffer weft yarns in the center plane of the fabric are lower melting point synthetic yarns. The fabric is heated to a temperature to cause the low melt temperature stuffer yarns to melt and flow in a way that they fill voids in the weave pattern, reducing permeability.
U.S. Pat. No. 4,731,281 discloses a papermaker's fabric, woven from uniformly precoated, totally encapsulated monofilament yarns. The yarns are coated prior to the weaving of the papermaker's fabric in order to impart anti-sticking characteristics to the papermaker's fabric. The coatings may be such that thickness of the machine direction yarns is different than the thickness of the cross-machine direction yarns.
SUMMARY OF THE INVENTION
The present invention is directed towards paper machine clothings comprised of interconnected bicomponent fibers. In one embodiment of the invention, the paper machine clothing is comprised entirely of bicomponent fibers in both the machine and cross machine direction.
The paper machine clothings described herein can be of a woven, knitted, or nonwoven construction. It should be understood that the bicomponent fibers are arranged in an orderly manner.
In the present invention, bicomponent fibers are used in at least one, but not necessarily all, of the layers of a paper machine clothing. For example, bicomponent fibers may be the fibers which comprise the surface contacting layer of the clothing, which contacts the fibrous material that is being formed into paper or related product.
Advantage is taken of the unique bicomponent fiber structure, which permits selection of different materials for the sheath and core components. For instance, the sheath material may have a melting point lower than the melting point of the core material. Accordingly, a fused, bonded structure of bicomponent fibers can be formed where the sheath component has a melting point lower than the core component. By heating a fabric constructed of bicomponent fibers to a temperature greater than the melting point of the sheath component and lower than the melting point of the core component, with subsequent cooling of the fabric to below melt temperature of the sheath component, a fused, bonded structure will result.
Suitable bicomponent fibers include sheath-core combinations of co-polyester/poly(ethylene terephthalate), polyamide/poly (ethylene terephthalate), polyamide/polyamide, polyethylene/poly (ethylene terephthalate), polypropylene/poly(ethylene terephthalate), polyethylene/polyamide, polypropylene/polyamide, thermoplastic polyurethane/polyamide and thermoplastic polyurethane/poly(ethylene terephthalate).
In a preferred embodiment of the invention, bicomponent fibers are the sole constituent fiber of at least one layer of a clothing. In the case of multiple layer clothing, at least one layer is constructed of bicomponent fibers, which could be the surface layer in contact with the paper sheet or the base layer. Whether the fabric is a single layer or multiple layer, the bicomponent fibers are to be arranged in an orderly non-random manner. By arranged in an orderly non-random manner, it is meant that fibers of a clothing run in a first direction; the first direction fibers do not intersect with other fibers running in the first direction; and that fibers of the clothing run in a second direction; the second direction fibers do not intersect with other fibers running in the second direction; that fibers running in the first direction intersect with fibers running in the second direction, and vice versa. For instance, fibers arranged in the machine direction will not intersect with each other and that such fibers will intersect only with fibers running in the cross machine direction. It is preferred that the clothings of the present invention be constructed of fibers running in the machine or cross machine direction, but such clothings could be constructed of fibers which run in directions that are at angles to the machine and cross machine direction of a paper making machine.
The use of bicomponent filaments in paper machine clothings offer improvements in both function and structure that are unrealized in clothings constructed of conventional monofilaments. Dimensional stability of fabrics are improved by heat fusion at cross over points. Heat fusion also improves resistance to soiling. Fabric thickness is decreased, that is, fabrics are of a reduced caliber, attributable to the use of finer filaments and reduced thickness at cross over points. Reduced thickness at cross over points also improves the planarity of the fabric.
Bicomponent fibers also form unique pore geometries upon heat fusion. Unique shapes are available depending on the kinds of filaments used in constructing fabrics. Reduced marking of the paper sheet is also another improvement over fabrics of conventional monofilaments.
The improvements mentioned above are desired by paper makers, particularly since the speeds on paper making machines are increasing. These properties are related to drainage, which is of greater concern on high speed machines. Smoothness and printability are also related to drainage, and on high speed machines these considerations may be compromised. Bicomponent fibers may offer a suitable solution to the problem, since fabric thickness, among other things, is reduced.
The aforementioned improvement in planarity of the fabric results in reduced marking of the paper sheet. This is highly desired by the paper maker.
In a preferred embodiment of the present invention, the clothings are constructed of yarns comprised of bicomponent multifilaments. That is, the yarns are formed of at least two bicomponent filaments arranged as multifilaments. At the appropriate time, the side-by-side bicomponent monofilaments are heat fused in the manner previously described. Such heat fusing could occur prior to fabric formation, or it could occur after the fabric has been formed.
Such bicomponent multifilament yarns, after heat fusion, have at least two core components set within a matrix of sheath component material, which after heat fusion forms a substantially unitary sheath around at the least two core components. The individual sheaths that existed prior to heat fusion cannot be discerned, while the at least two core components are distinct from the sheath and are distinct from each other.
As noted, the core material remains as a distinct region or regions within the sheath or matrix material. A typical failure mechanism of monofilaments is fibrillation, stress failure along the orientation direction of the filament. After bonding, the sheath becomes an non-oriented matrix less prone to fibrillation. In addition, the continuous matrix surrounding the plurality of cores will dissipate the stresses that induce fibrillation. Should a core element fibrillate, the continuous matrix will act as a bonding agent protecting the integrity of the entire structure. Ideally, the minimum sheath content is 10% cross sectional area up to a maximum of 50%.
The paper machine clothings of the present invention may be formed in any conventionally known matter. For instance, the bicomponent fibers that comprise the clothings may be woven, or they may be knitted in any pattern or configuration known to the skilled artisan.
One of the advantages that paper machine clothings of the present invention are believed to possess over conventional clothings comprised of monofilaments is that when woven (or knitted), such clothings exhibit relatively planar, knuckle free surfaces after fusion. It can be readily appreciated that when fibers are woven (or knitted), knuckles are formed which diminishes surface smoothness. When the temperature exceeds the melt temperature of the sheath component during heat fusion of bicomponent fibers, knuckle size is reduced when material flows and collapses, improving the surface smoothness. Surface smoothness is a factor which affects paper quality. Accordingly, clothings of improved smoothness are of interest to the manufacturer of paper and related products. A network of bonds between intersecting fibers will be formed upon heat fusion of a clothing comprised of bicomponent fibers. Physical bonding of this kind will improve the dimensional stability over a conventional clothing constructed of monofilament.
When running on a paper making machine, a fabric according to the present invention should remain cleaner than a clothing comprised of conventional monofilaments. Heat fusion of a fabric comprised of bicomponent fibers are characterized in part by fused, intersecting yarns. In contrast, conventional monofilaments have interstices or pinch points, where yarns intersect. Fusion at the intersections of bicomponent fibers diminishes, and possibly eliminates, such pinch points, where debris could otherwise collect and become entrapped between yarns. Accordingly, the heat fused intersecting yarns produced with bicomponent fibers provides a structure that should remain relatively cleaner than a clothing comprised of conventional monofilaments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of a method of making the present invention.
FIGS. 2a-2c are representative of the prior art.
FIGS. 3a-3b are side views of one aspect of the present invention.
FIG. 4 is a top view of the present invention.
FIG. 5 is a top view of the present invention.
FIG. 6 is a top view of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A simple bonded sheath/core structure was made from 250 denier yarns. This structure was made by fusing a plain weave prior to heat fusion. The final bonded structure of the clothing was relatively more planar than the unbonded fabric or a woven structure made from the same denier monofilament. A fused fabric woven from the sheath/core yarns will exhibit increased dimensional stability. After thermal bonding, each crossover point will become a welded joint in the fabric. Movement of the individual yarns will not be possible, and the fabric will move as a single unit. These welded crossover points also serve to eliminate frictional abrasion between the filaments. Physical bonding of this kind will improve the dimensional stability over a conventional clothing constructed of monofilament.
Several other advantages are also derived. Experiments show that the bonded fabric is significantly more resistant to high pressure shower damage than a woven structure. In a high pressure shower (HPS) test ring with a pressure of 3 MPa and a shower distance of 300 mm, the bonded fabric exhibited no damage after 180 minutes. The control fabric was damaged after 150 minutes. A bonded fabric after testing cannot be distinguished from the bonded fabric prior to testing. Secondly, for the same basis weight and weave pattern, abrasion resistance of the bonded structure is higher, since a greater surface area is in contact with the wear surface. In the woven fabric, the wear surface is the limited areas of high points of the exposed shute and warp filaments. Thermally bonded sheath/core filaments lead to structures with curved, smooth crossover points. Contamination of the fabric by mechanical bonding is minimal with the reduction of the interstitial space between the filaments as the crossover points.
While clothings of the present invention may be constructed of woven or knitted bicomponent fibers, it is not a necessary step in fabric formation, since the fibers of the clothing can be arranged in an intersecting pattern and then heat fused in order to affix the yarns of the clothing substantially in place.
Conventional weaving or knitting is not precluded in constructing clothings from these yarns, but other methods are possible. One process of making a fabric involves producing a warp, laying a second layer of shute direction yarns directly over the warp without weaving and passing the layered filaments through a heated zone at or above the melting point of the sheath material with or without applied pressure to bond at all the crossover points such as depicted in FIG. 1. This would be a faster manufacturing process to make very close spaced pore fabrics, such as those required for the first dryer fabric position in the papermaking process.
FIGS. 2a and 2b show cross sections of a layer of a triple layer fabrics woven from conventional monofilament. Caliper of the monofilament plain weave is 0.116 inch. FIGS. 3a and 3b show the caliper of a similarly woven layer of bicomponent monofilaments. Caliper is 0.070 inch.
FIG. 2c is a computer generated model of the machine direction monofilament contour shown in FIG. 2a. In the model, there are 3 variables: caliper, plane difference, and compression of the warp and shute. The objective was to use the model to match the actual monofilament sample, so caliper was fixed at 0.0116" and plane difference was fixed at 0.0001" shute-high, leaving the compression variable as the only unknown. Examination of the contours in FIGS. 2a-2b revealed that more compression was present in the shute strand. Therefore, in the model level 5 was selected for the shute compression and level 0 for the warp compression. This yielded a model image that matched the actual cloth for:
caliper (0.0116")
plane difference (0.0001" shute high)
mesh×count (86×77)
diameters (0.15 mm MD and CD)
Using the same computer model and constraining strand density, with diameters and surface plane difference remained the same as the sample, compression was taken as high as possible (20%) to determine the thinnest possible caliper available to the paper maker. The limit of 20% compression was obtained from empirical studies here using PET warps and shutes. A caliper of 0.0095" was obtained. Thus the caliper of 0.0070" with the BIKE layer is unattainable with monofilament components of these diameters.
The bonded structure can be used as a top layer in a multilayer PMC product to take advantage of the thinner structure, greater abrasion and soil resistance, improved resistance to drain for high pressure showering and the unique pore structure.
FIG. 4 shows a fabric of a plain weave construction, with yarns in the warp and shute directed being comprised of yarns wherein bicomponent fibers are braided around a Kevlar core. It can be observed from FIG. 4 that the yarns are interconnected with other yarns at the points at which the yarns intersect. This is attributable to the heat fusion of yarns, wherein the sheaths of the bicomponent materials fuse to each other after heating the fabric to a temperature above the melting point of the sheath material, yet lower than the melting point of the core material.
Both the warp and shute yarns of the fabric shown in FIG. 4 are of the same structure. The interior yarns are about 134 filaments of high modulus Kevlar 49. Around the Kevlar interior, eight bicomponent yarns are braided around the Kevlar interior. Each yarn is constituted of sixteen (16) bicomponent filaments. The filaments are a 250 denier, 16 filament count having a low melt copolyester sheath material and a poly(ethylene terephthalate) core, with the melting point of the copolyester sheath being lower than the melting point of the PET core, available as Bellcouple® from Kanebo.
The eight bicomponent yarns are braided around the Kevlar interior. Braiding forms a relatively stable structure, and the wrapped high modulus yarns can be used to form fabrics. Such fabrics are formed according to methods readily appreciated to one skilled in the art. After the fabric has been formed, it is placed under tension, heated to a temperature greater than the melting point of the sheath, yet lower than the melting point of the core, and then cooled to a temperature lower than the melting point of the sheath.
Because of the nature of fused covered bicomponent fibers and the unique structures they may form, fibers of denier lower than those for required for conventional monofilaments can be used. The use of lower denier fibers offers the advantage of a clothing thinner than a clothing comprised of conventional monofilament, without sacrificing fabric strength.
Because of the favorable characteristics attributable to high modulus materials like Kevlar, it is possible to construct fabrics that possess the same degree of strength, or an even greater degree of strength, than fabrics constructed of conventional materials while employing less material in fabric construction. That is, the fabrics of the present invention possess greater than or equal strength on a weight basis.
FIG. 5 shows a fabric wherein the yarns described in relation to FIG. 4 above are used in the warp direction. The shute direction yarns are comprised of 9 ply material. That is, they are a ply of nine yarns of bicomponent material as described in FIG. 4. The plied yarns are twisted loosely together. The yarns have a distinctly flattened appearance. That is, after heat fusion, the yarns take on a ribbon like appearance.
In addition, unique pores shapes are possible since individual filaments can be placed at oblique angles to the warp yarns. Another unique pore can result from using a knitted fabric of sheath/core filaments and subsequently bonding the structure as seen in FIG. 6. Again, this structure could be used as a top layer to a multi layer fabric for the unique pore shape with the other advantages cited for monoplanar fabrics.
The use of the sheath/core filaments in PMC press fabric add three benefits. Needle damage will be reduced. Needles can penetrate the yarn bundle with little damage to the bundle. Thus the batt fibers can be pushed through the yarns, and after bonding, the batt filaments will be essentially locked in place. Shedding of the batt fibers will decrease because of the thermal bonding. Capillary action may contribute to rewetting of the paper sheet after it emerges from the press nip. Water can be pushed forward along the warp fibers in the base fabric, and the water can return to the sheet after the nip. Thermal bonding of the base fabric will eliminate these paths for fluid travel. Water will be forced through the base fabric into the bottom web to be trapped and removed by vacuum techniques.
Several issues arise when discussing the effects of twist level in bicomponent yarns as the enter the loom. Yarns as processed contain little if any twist. If twist is present in as-shipped yarns, it is generally lost in the rewinding and warping operations. Untwisted yarns tend to fray and entangle as they progress through the loom. The entanglement results in shed that does not clear easily, so the manufactured fabric is woven by hand.
Twisted yarns will remain coherent bundles throughout the weaving process, avoiding the fraying and entangling problems and thus contributing to the overall weavability of the fabric.
Twisted structure has been shown to demonstrate higher breaking strengths when compared to flat yarns of the same nature, however, diminished returns are realized when the level of twist exceeds a critical value, beyond which the breaking strength actually decreases due to the axial orientation of the individual filaments and increased internal stresses. The strength of the yarns during the weaving process is of significance, and so the level of twist is of concern.
The level of twist can affect the overall nature of the fabric top surface. Fabrics woven with flat yarns were closed, that is, they lacked porosity, because the yarns flatten upon fusion into tape-like structures. A higher twist level will influence the roundness of the yarns in the finished structure. Twist level could control the porosity of the top laminate and that different fabrics could be manufactured simply by changing the degree of twist in the yarns. The geometry of the holes could be altered by the level of twist. Symmetrical twist in both the warp and shute directions will likely result in a square hole. Non symmetrical twist would likely result in a rectangular, elongated hole. Low levels of twist will result in a flatter fabric, and higher levels of twist will impart a texture to the surface, approaching the surface of a conventional fabric. Pore size can be changed without changing loom configuration. Pore geometry can be changed without changing loom configuration. Fabric surface characteristics can be changed using twist level. | The present invention is directed towards paper machine clothings comprised of interconnected bicomponent fibers. In one embodiment of the invention, the paper machine clothing is comprised entirely of bicomponent fibers in both the machine and cross machine direction. Advantage is taken of the unique bicomponent fiber structure, which permits selection of different materials for the sheath and core components. For instance, the sheath material may have a melting point lower than the melting point of the core material. Accordingly, a fused, bonded structure of bicomponent fibers can be formed where the sheath component has a melting point lower than the core component. By heating a fabric constructed of bicomponent fibers to a temperature greater than the melting point of the sheath component and lower than the melting point of the core component, with subsequent cooling of the fabric to below melt temperature of the sheath component, a fused, bonded structure will result. | 8 |
The invention involves an improved apparatus for, and method of, making fiber from a molten material and more particularly an improved fiber strand gathering and turning device.
BACKGROUND
In the manufacture of mineral fiber from molten material, it has been common practice to use a bushing made of precious metals including platinum, rhodium, palladium, ruthenium, iridium and alloys thereof. The bushings are electrically heated by their own resistance and are usually box-like, open on the top and comprise an orifice plate containing hundreds or thousands of orifices, with or without nozzles or tips welded or formed thereon, as shown by U.S. Pat. Nos. 4,207,086 and 4,078,413, which disclosures are hereby incorporated by reference. It is also known in flat plate bushings having no tips or nozzles such as disclosed in U.S. Pat. Nos. 3,905,790 and 4,229,198
Occasionally, and sometimes frequently, a fiber will break beneath the bushing for various reasons that are known. When a fiber break occurs, the loose fiber soon causes other fibers to break and soon all, or most, fibers being formed beneath the bushing are broken, a stoppage of desired fiberization. This is called a “breakout” in the industry. After a breakout begins, it is necessary to wait a short time, usually tens of seconds up to a few minutes, for beads of molten glass to form beneath each bushing orifice or tip, and become large enough that they break loose and fall from the bottom of the orifice plate or tip pulling a very coarse fiber, called a primary fiber, onto the floor, into a scrap bin, basement or scrap bin beneath the forming room floor. This is normally called “beading out” in the industry. Once beaded out, or as soon as the operator is available, the operator or starting equipment can then restart a strand containing the primary fibers into a chopper or winder and again begin making the desired product. Detectors for detecting when a breakout is occurring, and when desired fiberization is occurring, are known as evidenced by U.S. Pat. Nos. 4,130,406, 4,229,198, 4,342,579, 3,432,580, 4,401,452, and 4,925,471.
During normal operation of the bushing to make fiber products the fibers move away from the bushing at a high speed of thousands of feet per minute. The fibers are gathered into a strand of fibers, and the path of the strand is also often turned from a downward direction to a generally horizontal direction, using a pad wheel, a gathering wheel or shoe, hereinafter all referred to as a pad wheel. Some pad wheels are stationary and are simply rotated several degrees at frequent intervals to prevent wearing a flat place on the pad wheel. The fiber strand rubbing around 20-90 degrees of a stationary pad wheel substantially increases tension in the fiber strands versus a turning or rotating pad wheel. To reduce tension on the fiber strands, most pad wheels turn, but are plagued by what is referred to in the industry as strand wrap on the pad wheel. Strand wrap occurs because the fibers, being wet and usually also having a chemical sizing on the surface, tend to stick to the surface of the pad wheel and when the sticking becomes excessive, due to drying of residue on the wheel to tackiness, fibers tend to stay on the rotating wheel and wrap around the wheel. When this occurs the bushing has to be broken out, fiberization interrupted, the pad wheel cleaned and the bushing restarted making good fiber product. While an operator is tending to this time consuming act, other things needed doing are left undone and this causes additional bushing breakouts and lost production. Pad wheel wraps cause costly problems including scrap problems, quality problems and lost production.
U.S. Pat. No. 4,526,598 discusses the pad wheel wrap problem and discloses a rotating a rotating pad wheel designed to try to avoid pad wheel wrap. This pad wheel appears to be driven with a conventional motor, 120 volts, but there is no disclosure of RPM, driven direction or whether always driven. U.S. Pat. No. 4,692,178 discloses a pad wheel comprising a rotatable, generally disc-shaped hub that is provided with walls for supporting a plurality of generally cylindrical rods about the hub's peripheral edge with the rods spaced apart to provide surface contact reductions of more than 70 percent and up to as much as 95 percent. This latter pad wheel is free wheeling, i.e. driven by the moving fiber strands. Both pad wheels are or appear to be an improvement over what came before, but still have short-comings, particularly in how they are driven. The use of 120 volt motors in a forming room environment is dangerous because of the frequent or constant wet conditions around the pad wheel and have a short life in these conditions. On the other hand, a free wheeling pad wheel causes more tension on the fiber strands than necessary and, does not slow down quickly or stop quickly.
SUMMARY
The device of the invention comprises a pulley, pad wheel, having a grove around an outside periphery, a shaft for the pulley and a low voltage servo motor to turn the pulley. The groove can be any reasonable shape, but most typically is V or U shaped with the bottom of the V or U being closer to the axis of the pulley than the outer edges of the pulley. The bottom of the V is most typically radiused with the radius being in the range of about 0.0625 inch to about 0.250 inch. The device can be mounted in the desired position at a lower elevation than the bottom of a fiberizing bushing and spaced from the free fall path of primary fibers produced by the bushing. The mount can be attached to the servo motor or can be a plate or bracket to which the motor is attached. The shaft passes through an opening or open area of the mount such that the shaft is free to turn. By low voltage is meant a voltage of less than about 50 volts and most typically is about 24 volts, but other voltages below about 50 volts can be used. Using a low voltage motor results in a far safer system than the 110 volt AC motors suggested heretofore for use on driven pad wheels. Alternating current or direct current, variable speed motors or variable speed drives are suitable for the invention, and most desirable is a 24 volt, direct current, servo motor with a programmable controller for controlling the shaft speed in response to one or more sensors sensing a hanging mode and a desired fiberization mode.
The pulley is referred to as a pad wheel because originally in the industry pads containing a lubricant were used to gather the fibers from a bushing into a strand and turn the strand towards a winder. Direct chopping of the fiber was not developed until years later. In time the pads were replaced with a wheel like a pulley wheel and these were called pad wheels. This name has remained since, at least with some fiber manufacturers.
The device of the invention is driven, but is safer than previous driven gathering and turning pad wheels due to the lower voltage. Also, the device of the invention has lower maintenance that previous driven pad wheels because a servo motor is more reliable and durable in the harsh environment of a typical fiber forming room due to the presence of heat, wetness, and constant use. Another advantage is the ability of the device to operate differently during a breakout of the bushing than it does during normal operation. All too often during operation a fiber will break beneath the bushing for various reasons that are known. When a fiber break occurs, the broken loose fiber soon causes other fibers to break and soon all, or most, fibers being formed beneath the bushing are broken, a stoppage of desired fiberization. At such time, it is necessary to wait a short time, usually tens of seconds up to a few minutes, for beads of molten glass to form beneath each bushing orifice or tip, and become large enough that they break loose and fall from the bottom of the orifice plate or tip pulling a very coarse fiber, called a primary fiber, onto the floor, into a scrap bin, basement or scrap bin beneath the forming room floor. This is normally called “beading out” in the industry. Once beaded out, or as soon as the operator is available, the operator or starting equipment can then restart a strand containing the primary fibers into a chopper or winder and again begin making the desired product.
By “fiberizing” is meant the condition where fibers are being pulled from a bushing at a speed similar to that produced by a product-forming machine like a chopper or winder, usually at more than 1000 feet per minute. By beading out or breaking out is meant the mode from the time the first fiber breaks out, or from the time the operator or sensor senses that one or more fibers have broken out, until every operable tip has formed a bead of molten glass at the end of the tip, usually so heavy enough that it has fallen away from the tip to form a primary fiber. If one or more tips of the bushing are cold, i.e. cooler than the other tips, for some reason, those few tips will bead very slowly and need not be running a primary fiber for the bushing to be in the hanging mode. By “hanging” is meant a condition or mode where the fibers from the bushing have broken out and the bushing is in the mode where all or almost all of the operating tips are producing coarse, primary fibers and those primary fibers are moving downward due to their own weight, or are being pulled slowly by pull rolls, usually into a waste collection system or waste hopper. Thereafter, until the desired fiberization is restarted, i.e. all or most of the primary fibers from the bushing are inserted into a high-speed pulling device like a winder or a chopper, the bushing remains in a hanging mode.
The invention also comprises a method of making a fiber product from a molten material comprising passing a molten material through a bushing comprising an orifice plate or a tip plate having a plurality of orifices therein, forming a plurality of fibers, gathering the fibers into a strand using a driven pad wheel and turning, changing direction, the strand of fibers towards a winder or a chopper, the improvement comprising using as a gathering device a servo motor driven pad wheel, sensing when the bushing is breaking out and when the bushing is fiberizing and changing the RPM of the pad wheel to slow down the pad wheel when the bushing is breaking out and to speed up the pad wheel once the bushing is again fiberizing.
The present invention is applicable to any system or bushing that converts molten material to continuous fibers and particularly to systems and bushings that operate at temperatures above 1000 degrees F. Materials suitable for converting in the present invention are polymers, metals and mineral materials including glasses, ceramic compounds or mixtures of ceramic materials, slags and the like. The invention is particularly useful in making continuous glass fibers and products made using such fibers. While the invention is applicable to any glass used to make fibers, E glass is the most common glass used to make continuous fiber.
When the word “about” is used herein it is meant that the amount or condition it modifies can vary some beyond that stated so long as the advantages of the invention are realized. Practically, there is rarely the time or resources available to very precisely determine the limits of all the parameters of ones invention because to do would require an effort far greater than can be justified at the time the invention is being developed to a commercial reality. The skilled artisan understands this and expects that the disclosed results of the invention might extend, at least somewhat, beyond one or more of the limits disclosed. Later, having the benefit of the inventors disclosure and understanding the inventive concept, the objectives of the invention and embodiments disclosed, including the best mode known to the inventor, the inventor and others can, without inventive effort, explore beyond the limits disclosed using only ordinary skill to determine if the invention is realized beyond those limits, and when embodiments are found to be without any unexpected characteristics, those embodiments are within the meaning of the term about as used herein. It is not difficult for the artisan or others to determine whether such an embodiment is either as expected or, because of either a break in the continuity of results or one or more features that are significantly better than reported by the inventor, is surprising and thus an unobvious teaching leading to a further advance in the art.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of a typical fiber forming position in a forming room showing the device or apparatus of the invention.
FIG. 2 is a partial cross section of a one of many conventional pad wheels used in an embodiment of the in the invention.
FIG. 3 is a front view showing how the device of the invention is mounted beneath a bushing.
DETAILED DESCRIPTION
FIG. 1 is a perspective view of a typical bushing position for making fibers from a molten material. Molten material from a conventional source enters a bushing 2 that produces, during fiberizing mode, a plurality of fibers 4 . The fibers 4 are normally moving at a high speed, over 1000 feet per minute and often many thousands of feet per minute. In many fiber operations, but not all, typically the fibers have been sprayed with water to cool the fibers and are then optionally contacted with an optional, conventional chemical sizing applicator 5 that applies a conventional protective sizing composition to the surface of the fibers to protect the fibers from abrasion and to make the fibers perform better in a later application as is well known.
Dry, wet or sized fibers 6 are then gathered into a strand 9 with a driven pad wheel assembly 7 , according to the invention, comprising a pad wheel 8 , typically having a V or U shaped groove 10 in its outer periphery. The pad wheel 8 is driven with a servo motor 12 having a shaft (not shown) that passes through a hole 14 centered around the axis of the pad wheel 8 . A conventional key (not shown) sets in a key slot 15 in the pad wheel 8 and the shaft of the servo motor 12 to prevent the pad wheel turning on the shaft of the servo motor. Other means of securing the pad wheel on the shaft of the servo motor as is well known.
The driven pad wheel assembly 7 , as shown in FIG. 3 is mounted in a conventional manner to an arm and a vertical pipe that allows the pad wheel assembly 7 to be rotated out of the way for working on the bushing or sizing applicator. The servo motor 12 is mounted on a plate 16 , which in turn supports the pad wheel assembly 7 . The plate 16 is attached to an arm 18 that is attached to a swivel 20 mounted on a vertical member 22 , usually a pipe secured to a structural member (not shown) in the ceiling of the fiber forming room. A retainer ring 21 is clamped or threaded onto the pipe 22 at the appropriate vertical position to hold the swivel 20 on the vertical member 22 .
The servo motor 12 is a low voltage motor requiring a voltage of less than about 48 volts. A 24 volt, direct current, servo motor is very suitable, such as Model No. AKM12E-BNMNR-00 available from KOLLMORGEN located in Northhampton, Mass.
In the method of the invention, when a breakout sensor senses that the bushing is braking out, the signal from the sensor activates a controller for the pad wheel motor 12 , or drive, and slows the shaft speed of the motor 12 , according to a desired deacceleration rate programmed into the controller, to a very slow RPM, such as about 20 RPM. Later, when the operator starts the primary fibers from the hanging bushing into a puller such as a winder or chopper, or when the breakout sensor senses that the bushing is in a desired fiberization mode, the controller for the motor accelerates the servo motor 12 , according to a desired ramp-up rate programmed into the controller, to an RPM similar to the surface speed of the good product fiber strand in contact with the pad wheel 8 , such as a minimum of about 2000 RPM. This ramp-up can be triggered by a breakout detector, a switch that the operator throws, the chopper or winder controller or some other sensor.
Breakout detectors are well known as disclosed above in the Background section. Deceleration of the pad wheel should occur very soon after the beginning of a breakout to prevent wheel wraps. By very soon is meant within about 10 seconds after the beginning of a breakout. The rate of deceleration should be very fast, such as about 400 RPM/second. Many different rates of acceleration are suitable for the motor driving the pad wheel 8 and will vary depending upon many variables including the diameter of the groove in the pad wheel, the type of sizing on the fiber, the number and diameter of fibers being produced, the material of the pad wheel. A typical acceleration rate such as about 400 RPM/second is typical.
Use of the invention reduces maintenance costs, frees up the operator to address other important needs because wheel wraps are eliminated or substantially reduced. Also, motor maintenance is greatly reduced compared to using 110 volt AC motors. The breakout rate is significantly reduced, i.e. a longer average desired fiberization time vs hanging time. With a lower break rate comes a significant improvement in product quality.
Different embodiments employing the concept and teachings of the invention will be apparent and obvious to those of ordinary skill in this art and these embodiments are likewise intended to be within the scope of the claims. The inventor does not intend to abandon any disclosed inventions that are reasonably disclosed but do not appear to be literally claimed below, but rather intends those embodiments to be included in the broad claims either literally or as equivalents to the embodiments that are literally included. | Apparatus and methods for making a continuous fiber product by gathering a plurality of fibers into a strand in contact with a pad wheel that is driven with a low voltage, variable speed motor or drive, and controlling the RPM of the motor in response to a breakout detector. Other embodiments further include accelerating the RPM of the motor and pad wheel at a desired ramp-up rate following the resumption of desired fiberization. | 2 |
FIELD OF INVENTION
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 09/386,883 filed Aug. 31, 1999 and relates to a low viscosity filler composed of boron nitride agglomerated particles of spherical geometry, a process for forming a low viscosity filler of boron nitride agglomerated particles of spherical geometry and to a low viscosity boron nitride filled composition composed of a polymer selected from the group consisting of a polyester, epoxy or polyamide loaded with a low viscosity filler composition of BN particles in a concentration of between 30-50 wt. % BN with the composition having a viscosity below about 300 cp and preferably below about 250 cp.
BACKGROUND OF THE INVENTION
[0002] Boron nitride (BN) is a chemically inert non-oxide ceramic material which has a multiplicity of uses based upon its electrical insulating property, corrosion resistance, high thermal conductivity and lubricity. A preferred use is as a filler material additive to a polymeric compound for use in semiconductor manufacture as an encapsulating material or to form a low viscosity thermosetting adhesive or in formulating a cosmetic material. As presently manufactured boron nitride is formed by a high temperature reaction between inorganic raw materials into a white powder composition of BN particles having an hexagonal structure similar to graphite in a platelet morphology. The platelet morphology is for many applications undesirable and of limited utility. A conventional powder composition of BN particles has the physical attributes of flour in terms of its inability to flow. Accordingly, when added as a filler to a polymer a blended material is formed having poor rheological properties and at loaded concentrations above 30 wt. % BN the blended material is so viscous that it is difficult to dispense from a mechanical dispenser such as a syringe. The physical characteristics of the filled polymer are enhanced at loading concentrations above 30 wt. % BN. Accordingly, a powder composition of BN particles with an improved rheology for use as a filler at high loading concentrations would be desirable.
[0003] The surface morphology and shape of conventional platelet BN particles are modified in accordance with the present invention to form boron nitride agglomerated particles bound by an organic binder such that when filled into a polymeric compound at loading levels between 30 to 50 wt. % BN the viscosity of the filled composition remains below 300 cp and preferably below a viscosity of 250 cp.
SUMMARY OF THE INVENTION
[0004] In accordance with the present invention, a low viscosity composition of spherically shaped agglomerated particles of boron nitride can be formed by spray drying an aqueous slurry composed of boron nitride particles of random irregular shape in combination with an organic binder and a base adapted to maintain the pH of the slurry above about 7.3 and optimally above a pH of 7.5, at a sustained elevated temperature into a dry powder composition of spherically shaped BN agglomerated particles with the concentration of the organic binder in the slurry adjusted to at least above about 1.8 wt. % of the slurry to form a residue of organic binder and/or a decomposition layer from said organic binder on said particles for modifying the surface viscosity of the composition without degrading the physical properties attributable to boron nitrate such as high thermal conductivity.
[0005] Each BN particle in the composition of the present invention represents a composite agglomerate of non-spherical BN particles bound together by an organic binder in a generally spherical geometry. The diameter of each spherically shaped BN particle formed by the spray drying method of the present invention may vary in size over a relatively wide size distribution of sizes but may be controlled so that the majority of particles and up to about 98% of the BN particles have a minimum diameter above one micron and preferably a minimum diameter above about 5 microns. The size distribution of the BN particles may extend to a maximum diameter of about 275 microns. Although the size distribution is relatively wide the BN particles have an average size which falls into a much narrower size range between about 10 microns and 150 microns in diameter and can be adjusted to form an even narrower size range by adjustment of the physical parameters of the spray drying operation and/or the initial size of the non-spherical particles of BN in the slurry. Accordingly, the size of the spherical BN agglomerated particles formed in the spray drying process of the present invention can be controllably varied over of a preferred range of from as low as 1 micron in diameter to a preferred maximum diameter of about 75 microns so as to accommodate a variety of end uses.
[0006] The spherical shape of the BN particles formed in accordance with the present invention and the weight concentration of organic binder in the slurry controls the degree to which the particles flow and, in turn, the viscosity of the polymeric compound into which the particles are loaded. The ability to “flow” is an essential characteristic of the spray dried BN material when used as a low viscosity filler. The degree to which a material can “flow” is readily measurable as is well known to those skilled in the art. In contrast, a powder composition of conventional non-spherical BN is unable to flow and inhibits the flow characteristic of the filled polymer. The standard used in the present invention to establish the existence or non-existence of a flowable material is the ASTM B213-77 hall flow standard as is well known to those skilled in the art. In the present invention, it is essential to be able to load the BN spray dried particles into a polymeric compound at loading levels of above at least 30 wt. % BN and preferably between about 35 to 50 wt. % BN without increasing the viscosity of the blend above about 250cp. The BN particles can be loaded into any polymer selected from the group consisting of a polyester, a polymide or an epoxy.
[0007] A low viscosity BN filled composition is formed in accordance with the method of the present invention comprising the steps of: forming an aqueous slurry composed of irregular non-spherically shaped BN particles, water, an organic binder and a base for maintaining the pH of the slurry at a pH above 7.3, adjusting the concentration of organic binder to a minimum level above about 1.8 wt. % of the slurry and preferably above about 2 wt. %; spray drying the aqueous slurry into a powder consisting of agglomerated BN particles of generally spherical shape and adding the powder as a filler into a polymeric compound at a loading level of between 30 to 50 wt. % BN.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Other objects and advantages of the present invention will become apparent from the following description of the preferred embodiment when read in conjunction with the accompanying drawings:
[0009] [0009]FIG. 1 is a block diagram of a conventional spray drying apparatus for producing the agglomerated spherically shaped BN particles in accordance with the present invention;
[0010] [0010]FIG. 2 is a photomicrograph of the spherically shaped BN particles formed by the spray drying operation of the present invention at a magnification of 50×;
[0011] [0011]FIG. 3 is a typical graph of the particle size distribution of the collected BN particles from the spray drying operation of the present invention; and
[0012] [0012]FIG. 4 is a graph showing the relationship of viscosity at a given loading of spray dried BN filler particles in an organic binder relative to the weight percent of binder in the slurry forming the spray dried BN particles.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] [0013]FIG. 1 is a schematic block diagram of the spray drying apparatus used in the method of the present invention to form a powder composition of BN composite particles each of generally spherical shape. The spray drying apparatus 10 may consist of conventional equipment including an atomizer 2 and a source of air or an inert gas 3 , such as nitrogen, which forms an atomized spray of particles from an aqueous feed slurry 6 of water, a polymeric binder in the liquid phase and a base selected to maintain the pH of the slurry above a pH of 7.3 and preferably above a pH of 7.5. The atomized particle spray is preheated to a temperature in a range of 250° C.-360° C. preferably by preheating the nitrogen or air before injection at a desired feed rate into a spray drying chamber 1 with the outlet temperature between 110° C.-250° C. The BN particles in the feed slurry 6 preferably have a hexagonal crystalline structure although they may have a turbostratic structure. A dispersant, cross-linking agent and defoamer may also be included in the aqueous feed slurry 6 but are not essential. A polymerization initiator such as ammonium, sodium or potassium persulfate or other peroxide compound or other known polymerization initiator can be included to complete polymerization of the binder.
[0014] The particles formed in the spray drying chamber 1 are dried at an elevated temperature to a moisture level typically below 1% and collected. A cyclone 8 may be incorporated to remove superfine size particles before collection. The collected particles are solid particles having the same structure as the initial BN particles in the slurry 1 and will vary in diameter over a distribution range as shown in FIG. 3 from a minimum diameter size of one about micron up to about 275 microns with a mean particle size which varies based upon the size of the non-spherical BN particles, the concentration of binder, and the selected spray drying parameters of operation such as slurry ratio, feed rate, gas pressure etc. The mean particle size for the distribution of particles in FIG. 3 is about 55 microns but can be controllably adjusted.
[0015] In accordance with the present invention the powder BN product collected from the spray drying operation possesses particles which are essentially all of generally spherical geometry as evident from the photmicrograph of FIGS. 2 and 3. Each of the collected particles is a solid agglomerated particle formed of irregular non-spherical BN particles bound together by the organic binder in a spherical geometry. The high concentration of the organic binder in the slurry forms a coating over each of the recovered particles which at a concentration of over about 1.8 wt. % of the slurry varies the surface characteristic of the spray dried BN particles such that when added as a filler to a polymer selected from a polyester, epoxy or polyimide even under high loading levels at concentrations of between 30-50 wt. % BN, the flow characteristic of the filled polymer is not inhibited. In fact the viscosity of the filled polymer can be tailored to below about 250 cp. provided the concentration of organic binder is above about 2 wt. % of the slurry and optimally at about 2.5 wt. %. At a viscosity below about 250 cp. the filler polymer is easily dispensed through any conventional mechanical dispenser.
[0016] The organic binder is needed to bond the BN particles during spray drying and to modify its viscosity characteristic. The latter requirement limits the choice of organic binder to a water soluble acrylic or acetate which at high concentration has been found to function as a viscosity modifier. A preferably acrylic binder is formed from monoethylenically unsaturated acid free monomers comprising C 1 -C 4 alkyl esters of acrylic or methacrylic acids such as methly acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and isobutyl methacrylate; hydroxylalkyl esters of acrylic methacrylic acids such as hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate; acrylamides and alkyl-substituted acrylamides including acrylamide, methacrylamide, N-tertiarybutylacrylamide, N-methacrylamide and N,N-dimethacrylamide, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate; acrylonitrile and methacrylonitrile. The monoethylenically unsaturated acid free monomer may include the acrylic monomer styrene so as to form a copolymer or may be formed solely from styrene. Preferred examples of acid free monomers include butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, acrylamide, methacrylamide, N-tertiarybutylacrylamide and styrene as a copolymerization agent. Acid containing monomers are less desirable but may equally be used. Such acid containing monomers may be selected from any carboxylic acid monomer preferably acrylic acid and methacrylic acid.
[0017] Although any acetate may be used for the organic binder a metal acetate is preferred over a non-metal acetate. The preferred metal acetates include nickel acetate, aluminum acetate, titanium acetate and any transition metal oxide acetate such as zinc acetate. Ammonium acetate is less desirable but is an acceptable non-metal acetate. The elevated drying temperatures used in the spray drying operation may cause the acetate to partially or entirely decompose to an hydroxide film on the surface of the BN agglomerated particles. The concentration of binder and any hydroxide decomposition layer formed on the agglomerated BN particles following spray drying should remain essentially at the same molar ratio as the corresponding weight ratio of binder to boron nitride in the slurry. Accordingly, for a concentration of at least 1.8 wt. % of binder in the slurry, the molar ratio of binder to boron nitride should be in a range of 0.00170-0.008 particularly for metal acetate binders.
[0018] The base can be selected from any suitable alkaline which will enable the pH of the slurry to be controllably maintained above a pH of 7 and preferably above 7.3. A preferred base is an hydroxide such as ammonium hydroxide or an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide or a methyl or ethyl ammonium hydroxide.
[0019] The following are examples of four ceramic slurries spray dried in accordance with the present invention to substantiate the production of spherical BN particles from a feed slurry of non-spherical irregular shaped BN particles. The four slurries consisted of conventional non-spherical BN powder in water with feed solids ranging from 32% to 49%. The pH of each slurry sample varied between 7.75 and 8.5. The pH was controlled by the addition of an ammonium hydroxide buffer at a concentration of less than 0.5wt %. The binder selected for each example was “Efka” 4550 in a concentration of between about 1 to 5wt %. “Efka” is a registered trademark of the Lubrizol Corporation and is a polyacrylate. A resin dispersant Efka 1501 which is a polyester fatty acid from Lubrizol at a concentration of about 0.25-2.00% was also added. Alternate binders which were found to be just as effective include “DURAMAX” 1022, “DURAMAX” 1020 and “DURAMAX” 3007. “DURAMAX” is a registered trademark of the Rohm and Haas Company in Philadelphia Pa. “DURAMAX” 1020 and “DURAMAX” 1022 are styrene/acrylic copolymers formed from acrylic monomers. It was not necessary to add any resin dispersant. However, a buffer such as ammonium hydroxide used to adjust the pH of the non-spherical BN particle aqueous slurry to above 7.3 was essential.
[0020] The following four tables contain all of the process conditions of the spray drying operation:
TABLE I BN SLURRY FEED PROPERTIES Feed Number 1 2 3 4 Feed Material Boron nitride (BN) slurry in Water Percent EFKA binder 0.25-4.0 Run Number 1 2 3 4 Solids, %* 32.7-49.0 Temperature, ° C. 19 23 19 19 Density, g/cm 3 1.292 1.195 1.194 0.963 pH 7.75 8.44 8.38 7.77 Viscosity, Avg. CP 104 706 806 3006
[0021] [0021] TABLE 2 BN TEST DATA PROPERTIES PRODUCT: Run no. 1 2 Sample location Chamber Chamber Cyclone Sample time 10:40 11:10 12:15 Sample weight, g 195.8 210.3 199.5 Total weight, kg 0.59 7.17 9.48 Total residual moisture, % 2 0.30 0.50 0.35 Bulk density, g/cc 0.551 0.562 0.521 Tapped density, g/cc 0.621 0.631 0.611 Particle size, microns, 10% less than 27.02 30.09 11.00 50% less than (median size) 94.07 112.13 23.31 90% less than 189.84 180.28 87.87 Chamber-to-cyclone ratio (kg/kg) 0.82
[0022] [0022] TABLE 3 BN TEST DATE PROPERTIES PRODUCT: 2B Run no. Sample location Chamber Cyclone Sample weight, g 132.6 74.9 Total weight, kg 5.26 5.33 Total residual moisture, % 0.45 0.79 Bulk density, g/cc Particle size, microns 10% less than 23.49 15.09 50% less than (median size) 55.03 25.42 90% less than 142.60 43.90 Chamber-to-cyclone ration (Kg/Kg) 2.15 0.99
[0023] [0023] TABLE 4 BN TEST DATA PROPERTIES Run no. 3 4 Sample location Chamber Cyclone Chamber Cyclone Sample weight, g 141.6 85.2 110.5 NA Total weight, kg 3.04 6.24 1.13 1.50 Total residual moisture, % 0.59 0.43 0.41 0.39 Bulk density, g/cc 0.331 0-.221 0.305 0.273 Tapped density, g/cc 0.09 0.287 0.382 0.342 Particle size, microns 10% less than 10.83 8.46 7.22 6.91 50% less than (median size) 25.85 14.59 14.69 12.87 90% less than 102.38 21.66 25.89 20.37 Chamber-to-cyclone ration 0.49 0.75 (kg/kg)
[0024] The following is another example for forming spray dried boron nitride particles in accordance with the present invention. In this example aluminum acetate is used as the organic binder and bismaliamide is used as the polymer.
[0025] A boron nitride powder PT 120 (Lot 5151) was used to demonstrate the effect of surface modification on the viscosity of the BN filled resin. A conventional thermosetting resin, bismaliamide (BMI), from Quantum Chemical was used as the polymer into which non-spherical BN particles were loaded. PT120 is a conventional boron nitride powder with a platelet morphology. The physical and chemical characteristics are shown in the following Tables 5A-5C.
[0026] The PT120 filled resin was spray dried using a laboratory scale spray dryer, Mobile Minor Hi Tec, made by Niro Atomizer.
[0027] A slurry was prepared by mixing boron nitrate in de-ionized water using a high intensity mixer. Aluminum acetate-dibasic was added to the slurry and the slurry was mixed. After stabilizing the slurry, spray dying was initiated. The slurry composition for three separate runs is described in Table 5A.
TABLE 5A Run No. 5D7 SD8 SD9 Water (gm) 3000 3500 3000 Boron Nitride (gm) 1050 1225 1050 Aluminum Acetate- 52 91.88 26.25 Dibasic (gm) BN/Water (wt. %) 35 35 35 Al. Acet./BN (wt. %) 5 7.5 2.5
[0028] After the slurry was prepared, it was kept agitated by the mixer. The slurry was then pumped into the feed section of the spray dryer by using a peristalic pump. The spray dryer was operated with its fan on, inlet temperature in the range of 250° C.-270° C. The outlet temperature was in the range of 110° C. to 150° C. Air flow was set in the range of 17 to 22 on the gauge. Boron nitride feed rate (powder basis) was 1016, 1050 and 841 gm/hr for SD7, SD8 and SD9 respectively. Powders were collected from chamber and cyclone and then tested for their rheological properties.
[0029] Rheological Testing:
[0030] Powders were mixed with the BMI resin alone at 37.4 wt. % loading level to form a baseline. About 30 gm. of resin was used in each case. After careful mixing in a cup, it was placed in a vacuum chamber for removal of trapped air. After evacuating for a few hours, it was carefully mixed and then placed into evacuation chamber again. Once air bubbles stopped rising to the surface, the cup was removed. The resultant paste was gently stirred and placed in a water-cooled bath for equilibrating to 25° C. After it reached a constant temperature of 25° C., viscosity was measured by Brookfield rheometer DVII using spindle no. 96. Viscosity was measured at various speeds but the measurements taken at 5 rpm ware used for comparison. Measurements were taken after at least 5 minutes from the start of the rotation to obtain steady state value.
[0031] The results of viscosity tests and analytical data are given in Table 5B and 5C for powders collected from chamber and cyclone respectively.
TABLE 5B PT120- SD7- SD8- SD9- Baseline Chamber Chamber Chamber % Oxygen 0.371 5.17 5.71 % Carbon 0.021 0.58 0.84 Surface Area 2.97 4.5 7.91 8.68 MicroTrac Size D-10 (Microns) 6.15 D-50 (Microns) 12.32 D-90 (Microns) 21.71 Shape Plate Spheroidal Spheroidal Spheroidal Agglomerage 70-150 70-150 70-150 Size (microns) Viscosity @ 400,000 141,000 74,000 242,000 5 RPM (cps) Comments No Increased Increased Increased aluminum surface surface surface acetate - no area due to area due to area due to spherical- coating coating coating ization
[0032] [0032] TABLE 5C PT120- SD7- SD8- SD9- Baseline Chamber Chamber Chamber Agglomerage Size 10-50 10-50 10-50 (microns) Viscosity @ 5 RPM 400,000 258,000 216,000 402,000 (cps) | A low viscosity filler boron nitride agglomerate particles having a generally spherical shape bound together by an organic binder and to a process for producing a BN powder composition of spherically shaped boron nitride agglomerated particles having a treated surface layer which controls its viscosity. | 2 |
FIELD
[0001] The specification relates to pleatable materials, or fabrics, for use in filtration, and more particularly for use as pleated “filter bags” in baghouse-type dust collectors, for example.
BACKGROUND
[0002] A dust collector is an equipment to remove particles in an industrial fume. Typically the collector contains between hundreds to thousands of cylindrical elements referred to as bags. The bags are made of a filtration fabric that is porous. As the gas flows through, the porous filtration fabric collects particles. The particles can form a cake on the surface after minutes of operation, and the bags are typically cleaned by a reversed jet.
[0003] One of the important parameters of the filtration fabric is the filtration efficiency. The efficiency of filtration of bags is related to the total surface area. Typically, if the surface area is increased, then the velocity of gas and particles going through the fabric will be reduced, which decreases the probability of undesired particles going through the fabric and can consequently reduces the particle emissions. Moreover, a higher surface area can reduce the probability of particles getting embedded into the fabric in a manner where they resist the reversed jet, thereby increasing the lifespan of the filter. It is also possible, by increasing the surface area, to increase the capacity of a dust collector. It is thus generally sought to increase the surface area of the bags in dust collectors, where possible.
[0004] Typically, pleated bags have a greater surface area than non-pleated bags (i.e. simply cylindrical bags). Using pleated bags instead of non-pleated bags is thus one way of increasing the surface area without necessarily increasing the overall size of the dust collector system. In many cases, replacement of non-pleated bags by pleated bags can increase the surface area by two to three times.
[0005] Pleated bags can be made using a pleatable material which keeps its shape after pleating. The pleating can be done with a pleating machine. Some pleating machines operate at room temperature.
[0006] Alternately, for some materials which require thermosetting to retain their pleats, pleating machines having heating blades are used to fold the fabric and keep pressure on the pleats until the fabric is cooled back to room temperature. Heretofore, such processes have been used with polymers that can be thermally formed and have a relatively small density.
[0007] Some materials that are not thermally formable per se can be made so by adding a thermo-setting resin. An example of this is fiberglass felt impregnated with phenolic resin. The temperature of blades allow setting of the phenolic resin which subsequently acts to maintain the shape of the pleats. The reaction being irreversible, the pleats subsequently keep their shape even at high temperature.
[0008] However, even given the state of the art, some filtration materials could not be pleated by the known means and therefore remained known as being unpleatable. Nevertheless, given some desired characteristics, at least one of these ‘unpleatable’ filtration materials remained a popular choice for some specific applications despite the fact that it was not available in pleated form. There thus remained a strong need for an equivalent to such ‘unpleatable’ materials in pleated form due to the many advantages of pleats in filtration. This called for improvement.
SUMMARY
[0009] As it will appear from the description below, a filtration material such as a PTFE felt covered by an E-PTFE membrane, which was traditionally known as unpleatable, can now be made pleatable by felting with a pleatable scrim, more particularly a pleatable metallic scrim. There are many metals which are pleatable when provided in apertured sheets, and the pleatability of a metallic scrim can take precedence on the pleatability of both the felted PTFE and the E-PTFE membrane. Felting by hydro-entanglement (spunlacing) can be better suited than needle-felting when using a metallic scrim.
[0010] In accordance with one aspect, there is provided a pleatable filtration material comprising a felt having PTFE fibers felted onto a pleatable metallic scrim, a permeability of at least 20 l/dm 2 /minute at 12 mm of water gauge and a weight between 100 and 1000 g/m2, the felt having a density between 150 and 1000 g/m 2 and a permeability greater than that of the scrim and between 20 and 250 l/dm 2 /minute at 12 mm of water gauge; and a membrane laminated onto the felt, made of E-PTFE and having a permeability of between 3 and 75 l/dm 2 /minute at 12 mm of water gauge, preferably between 12 and 50 l/dm 2 /minute at 12 mm of water gauge; wherein the filtration material can be pleated using a traditional pleater at room temperature and thenceforth retain its pleats.
[0011] In accordance with one aspect, there is provided a process of making a pleatable filtration material comprising felting PTFE fibers onto a pleatable metallic scrim having resistance characteristics at least comparable to that of the PTFE fibers, a permeability of at least 20 l/dm 2 /minute at 12 mm of water gauge and a weight between 100 and 1000 g/m2, until a felt density between 150 and 1000 g/m 2 in addition to the density of the scrim and a permeability greater than that of the scrim and between 20 and 250 l/dm 2 /minute at 12 mm of water gauge are reached; and laminating an E-PTFE membrane having a permeability of between 3 and 75 l/dm 2 /minute at 12 mm of water gauge, preferably between 12 and 50 l/dm 2 /minute at 12 mm of water gauge onto a face of the felted PTFE fibers.
[0012] In accordance with one aspect, there is provided a pleated filter bag for use in a bag house dust collector, the filter bag being elongated and comprising a longitudinal hollow center with an open end, and a pleated filter wall transversally circumscribing the hollow center, the pleated filter wall having a felt felted onto an apertured and pleatable scrim and having a permeability lower than a permeability of the scrim and appropriate for filtration applications, and a membrane having a permeability substantially lower than the permeability of the felt and covering the felt on the outer side thereof facing the hollow center, wherein all of the scrim, the felt, and the membrane are resistant to a harsh filtration environment of the dust collector.
[0013] In accordance with another aspect, there is provided a filter fabric construction which incorporates a pleatable scrim to the base felt. The pleatability of the scrim takes precedence on the pleatability of the remaining components of the filter fabric, thereby rendering the filter fabric pleatable. This construction, or associated production method, can make pleatable a material such as PTFE, which was traditionally known as non-pleatable.
[0014] In accordance with another aspect, there is provided a pleatable filtration fabric having an E-PTFE laminated PTFE felt. This filtration fabric is made pleatable while at least substantially maintaining the thermal and chemical resistance characteristics of the PTFE by making the PTFE felt with a pleatable, heat-resistant and chemical-resistant scrim. The pleatability of the metallic scrim takes precedence in the combination and makes the entire material pleatable.
[0015] It will be understood that in the instant specification, the expression “pleatable” is to be understood in the context of operability in filtration. A pleatable filtration element will retain its pleats for a reasonable lifespan in the context of a normal or recommended use. For instance, a felt of polyester with a polyester scrim can be viewed as a non-pleatable fabric, whereas spunbounded polyester, which is denser and stiffer, can be viewed as pleatable.
DESCRIPTION OF THE FIGURES
[0016] In the appended figures,
[0017] FIG. 1 is a perspective view, fragmented, showing an example of a felt having a pleatable scrim.
DETAILED DESCRIPTION
[0018] One example of a material which was still used in unpleated form is polytetrafluoroethylene (PTFE), at least partly because of its exceptional thermal and chemical resistance characteristics which made the only viable choice for some harsh environments. An example of an application where unpleated PTFE-based bags were still used is dust collectors of waste incineration facilities. Incinerated wastes typically contain plastics which emit aggressive chemicals such as HCl, H2SO4, and HF during combustion. PTFE was appreciated for resisting to the combination of high temperatures (˜150 to 260° C.) and aggressive chemicals present in such waste incineration gaseous by-products. In applications such as waste incineration where tolerated emission levels were quite low, the PTFE fabric can be covered by a membrane to get a more efficient degree of filtration. A porous expanded PTFE membrane (E-PTFE) can be used to this end, laminated on the PTFE felt.
[0019] Tests attempting to pleat a PTFE felt (with or without catalyst) with a PTFE scrim failed. After pleating, the shape was not kept in a satisfactory way. Further, adding resins to the PTFE was found inefficient, at least partly due to the lack of adhesion and wetting by many of the tested resins on PTFE fibers.
[0020] The mere continued use of non-pleated PTFE filtration bags in dust collectors of applications such as waste incineration facilities, in itself demonstrates the former unavailability of this material in pleated form, considering the strong incentives for using pleated bags instead of cylindrical bags.
[0021] As will be detailed below, it will be understood how such materials and others can now be pleatable by felting the fabric onto a pleatable scrim. A type of pleatable scrim which can be used in making a PTFE felt pleatable is a metallic scrim.
[0022] FIG. 1 shows an exemplary sample of a PTFE felt spunlaced onto a metallic scrim. In this example, the metallic scrim is a square steel screen. As shown in the cut-out portion on the bottom and left-hand side corner of the sample, the metallic scrim is sandwiched between two layers of PTFE felt. In fact, during hydro-entanglement of the PTFE fibers, the fibers are placed on one side of the scrim, and partially pass through it, to the other side. The right-hand side of the sample is shown pleated. The E-PTFE membrane (not shown in the illustration), can later be laminated onto one face of the PTFE felt with metallic scrim. The PTFE felt can act as a support layer for the E-PTFE membrane which has a permeability substantially lower than the permeability of the felt. In use, the E-PTFE membrane faces the outside of the filtration bag and determines the relatively low permeability of the filtration material. The felt can thus be used to provide a cushioned support to the membrane, and, in combination with the metallic scrim, gives mechanical resistance to the membrane which acts as the actual “filter” during use but which is not practically usable alone. In fact, in many applications, the stresses which would be imparted to the E-PTFE membrane by the scrim during use if it was adhered directly thereto instead of being supported via felt, would result in an E-PTFE membrane having a very short useful life. The metallic scrim additionally provides pleatability to the filtration material because its higher pleatability takes precedence in the assembly.
[0023] The felt can be made of expanded porous or non-expanded PTFE fibers. The felt can be made by spunlacing the fibers onto the metallic scrim by a water jet—a process commonly referred to as hydro-entanglement. Hydro-entanglement can allow to avoid or reduce damage to the metallic scrim which could result if using conventional needle felting instead. The felt can have a density between 150 and 1000 g/m 2 , preferably between 250 and 700 g/m 2 , and a permeability between 20 and 250 l/dm 2 /minute at 12 mm of water gauge, preferably above 100 l/dm 2 /minute, for example.
[0024] The metallic scrim can be made of galvanized steel, stainless steel, aluminum, aluminium alloy, bronze, brass, copper, copper-based alloy, nickel, nickel-based alloy, or any suitable metal or alloy, provided it has suitable pleatability and resistance, and that it is ductile enough to be pleated without breaking. The metal can be a woven mesh, a punched metal sheet or any method that will create a metal sheet with suitable apertures in it. The permeability of the material should be greater than the permeability which is desired of the felt, preferably at least 20 l/dm 2 /minute at 12 mm of water gauge. The weight of the metal scrim can be between 100 and 1000 g/m 2 , preferably between 300 and 700 g/m 2 for example. Metallic scrims of various known types of metals can have chemical and temperature resistance characteristics suitable for harsh applications.
[0025] The felted support layer can be treated with a binder prior to lamination of the membrane, or the binder can be omitted. The fibers of the felt can act in a binding manner in certain applications. If used, the binder can be a fluorinated ethylene propylene copolymer (FEP) or a hexafluoropropylene-tetrafluorethylene copolymer, for example, or any other suitable binder. The binder can be provided at a concentration of between 25-50% by weight in a liquid suspension, and be either sprayed on a selected side of the support layer or transferred thereon using a roll. The material can then be heated in an oven at ˜120 to 240° C., to evaporate the solvent. After evaporation, the weight of transferred solid binder can represent a relative weight of between 1% and 10% (relative to the weight of the fabric).
[0026] The membrane, which can be made of commercially available E-PTFE, preferably has a permeability between 3 and 75 l/dm 2 /minute at 12 mm of water gauge, more preferably between 12 and 50 l/dm 2 /minute at 12 mm of water gauge. The membrane can be laminated on the side having the binder at a temperature of 270° C.
[0027] It will be noted that in some instances, PTFE felt for use in applications such as incinerators can have particles of catalyst deposited on the surface or embedded into the PTFE fibers. This can be desirable in a pleatable fabric and typically does not affect pleatability. For example, some catalysts help reducing emissions of dioxin, furan or nitrous oxide from waste incineration. The catalyst typically is typically provided a volume less than 20% of the volume of the PTFE fibers. Examples of catalysts include titanium dioxide (TiO 2 ), iron and cobalt (provided in the form of oxides), nickel, platinum and palladium. Other examples of catalysts include zeolith, copper oxide, tungsten oxide, aluminum oxide, chromium oxide, gold, silver, rhodium etc. If used, the catalyst should be provided in a particles size of less than 10 microns, but can be of any suitable shape, such as spheres, whiskers, plates, flakes, etc.
[0028] A resulting pleatable filtration material, or fabric, can include PTFE fibers spunlaced to a steel scrim, covered by a membrane. Such a fabric can be pleated using a traditional pleater operating at room temperature. The use of a pleatable metallic scrim can render the use of heated pleater blades unnecessary. An exemplary embodiment thereof is provided below:
EXAMPLE 1
[0029] PTFE fibers are spunlaced onto a 400 g/m 2 stainless steel scrim by hydro-entanglement. After entangling the total weight is 800 g/m 2 . The permeability of the material at this step is about 200 l/dm 2 /minute. The resulting felted support material is then sprayed with a suspension of FEP particles to add about 25 g/m of FEP particles after drying at 150° C. Then, an E-PTFE membrane is laminated thereon with the temperature of the FEP particles raised to 270° C. The resulting filtration material has a weight of 825 g/m 2 , and a permeability between 15 and 30 l/dm 2 /minute at 12 mm of water gauge, and is pleatable at room temperature.
EXAMPLE 2
[0030] Titanium dioxide particles of less than 10 microns in size are mixed with a PTFE dispersion. The titanium dioxide can correspond to 1-90% by volume, preferably 25-85% by volume, for example. The paste is extruded and calendered to form a tape. The tape is slitted along the length, expanded and processed over a rotating pinwheel to form fibers. These fibers with catalyst on the surface are spunlaced onto a 500 g/m2 stainless steel 316 scrim by hydroentanglement. After entangling the total weight is 900 g/m2. The E-PTFE membrane is laminated directly on the surface of the catalytic felt, the fibers acting as the binding agent. The resulting material has a weight of 900 g/m2, a permeability between 15 and 30 l/dm2/min at 12 mm of water gauge and is pleatable at room temperature.
[0031] It is to be understood that above example is given for illustrative purposes only. Alternate embodiments can be realized. For instance, thicker or thinner fabrics can be realized using more or less spunlaced PTFE, and different E-PTFE membranes. The pleatable metallic scrim can be applied to materials other than PTFE. Further, other scrim materials than metals can have similar pleatability and resistance characteristics. The use of a catalyst is optional. Given the above, the scope is indicated by the appended claims. | The pleated filter bag, which can be used in a bag-house type dust collector, is elongated and has a longitudinal hollow center with an open end, and a pleated filter wall circumscribing the hollow center. The pleated filter wall has a felt such as PTFE fibers felted onto an apertured and pleatable scrim which can be made of metal, and having a permeability lower than a permeability of the scrim. A membrane of lower-permeability material, such as an E-PTFE membrane, covers the support felt on the outer side of the bag. | 3 |
FIELD OF THE INVENTION
[0001] This application relates to the field of music, and more specifically to stepped pitch stringed instruments such as guitars crafted for tone generation to a particular fret and nut morphology having a bass portion of the fret offset from another more treble portion of the same fret holding the traditional vertical alignment. The use of parallel multi-angled frets enables better fingerings for certain alternate tunings other than the common Barre F intonation where the strings are tuned to E, A, D, G, B, E (lowest string to highest string). The structure of a multi-angled fret follows a minimum of two angles of travel as the fret spans or traverses the neck or fretboard.
DESCRIPTION OF THE RELATED ART
[0002] The use of vertically straight frets relative to the horizontal flow of strings has long been the accepted method to build stringed instruments. This is because vertically straight frets accommodate themselves well to the use of barre techniques by players to move chords up the neck employing the most prevalent string tuning sequence E, A, D, G, B, E known as Barre F tuning.
[0003] For instruments that are not designed to Barre F limitations such as the Ukranian Bandura, serious alterations to vertical fret arrangements are possible. Slanted fret instrument are not designed to be chorded in the efficient manner of guitars. U.S. Pat. No. 3,635,116 by Pelensky shows a modified instrument with bass neck frets slanted no less than 35 degrees from vertical, where the horizontal long neck defines a 90 degree reference to imaginary zero degree frets such as are used on guitars. Even frets as steeply angled as 45% are possible here because the desired utility of these instruments is given from selecting individual pitches in rapid fire mannerisms and the efficient use of a barre finger is not the utility sought.
[0004] As with Pelensky, more recently Kolano in U.S. Pat. No. 6,034,310 also cites straight frets expressing no bending or curvature. However, the Kolano fret is slanted in any and all conceivable configurations except vertical.
[0005] For inventions where the frets are not straight, the alteration of the shape of frets in the prior art has mainly been as a means of relief to flatten certain fret positions that have tiny positional errors due to the thickness of strings, the concave surface of some fretboards, and the fanning effect as the strings progress away from the nut. This is because perfect intonation when strictly straight and vertical frets are employed has been difficult to attain.
[0006] Some recent attention has been devoted to this intonation problem in the prior art including methods altering the transverse vertical perfection of a portion of the frets. This is best studied in U.S. Pat. No. 5,760,320 by Ward et al. but also in U.S. Pat. No. 6,156,962 by Poort who deviates the vertical alignment of the nut rather than the frets for the same problem. Although useful to his intent of correcting the intonation, the cited hot spot irregular alterations by Ward erodes the parallel nature of the frets to each other by disrupting their symmetry, and stretches the boundaries of a process termed locked fret loci which has been used by guitar manufacturers for centuries.
[0007] In terms of equal temperament fret design, as one moves along up the neck from fret to fret, on average the distance traversed should express 100 cents of sharping to create the next serial semitone in the scale. A typical fret services six strings, and the position where a given string would contact a given fret is called a fret loci. For any given two frets, if the comparative distance of all six loci from one fret to. the other six loci is an identical distance, then they display the condition termed locked fret loci. This signifies an identical shortening of string length for two different strings of the same open sounding length according to traditional rules of fret design.
[0008] In the real world, the actual pitches sounded may not be the usually desired 100 cents of sharping for certain individual hot spot loci, and this is the problem addressed by many inventors such as Ward and Poort. Their inventions are to overcome perceived hot spot intonation deviances usually of a few cents error. The instant invention does not address hot spot correction, as the main instant utility described is to improve fingering ease. The instant deviations to traditional structure of the frets are cited in a manner to maintain locked fret loci at all times. Because the instant invention uses locked fret loci, there will be hot spot errors present as in the common guitar, but correcting these instant hot spots is not the subject of this paper. Rather the subject is the offset manner of the structure of certain portions of the instant frets relative to the non-offset portions of the instant frets.
[0009] So ignoring the hot spot problems, and assuming that the rough values achieved by traditional guitar frets are perfect in the real world, the following is true. To compare the vertical perfection of a given fret, any two loci on the fret can be checked for the cent value the thicker string loci flats relative to a “virtual” vertical fret passing through the thinner string loci. If as in the standard model the two loci of a particular one fret servicing two particular strings are in vertical alignment, this alignment condition is termed 0 cents tryst. Deviations such as described by Ward are measured as cents flatted from perfect tryst. Ward calls for a maximum tryst value of 8.333 cents for a particular string loci relative to another string loci of the same first or second fret. This means for a given fret the effected loci will by intent and design flat the pitch up to 8.333 cents from the theoretical value it would have sounded if left at 0 cents tryst. This is a precise measure system, because the physical distance between adjacent frets varies.
SUMMARY OF THE INVENTION
[0010] The use of non-vertical, non-straight frets has been almost totally avoided in the guitar art because it fights the accepted fingerings developed over generations for Barre F tunings. Herein is cited the use of multi-angle frets for other than Barre F. The instant frets use a plurality of angles of travel for the loci, which are spaced along the playing surface of the neck or fretboard. Thus for one fret, a straight line will not pass through all the loci. In every embodiment, the two treblemost loci have a traditional vertical angle of 0 cents tryst. However, at least one of the other loci will be offset.
[0011] It is therefore accordingly an object of the present invention to provide a multi-angle fretting arrangement for guitars that will favor certain other musical tuning systems than Barre F tuning. This is done by providing a fretted playing surface for these guitars that either reduces the number of barre chords to a minimum by increasing open chording fingerings for the user, or eases the finger placement when barre chords are employed. Open chords are voicings that have at least one string unfretted.
[0012] An arrangement of the pitches expressed by the six open strings of a guitar can be tensioned to the series as calculated from thickest string to thinnest string: major third, minor sixth, fourth, major third, fifth. If the lowest pitch is D, this series completes as F#, D, G, B, E herein termed dropped D major. Another arrangement of the pitches expressed for instance by the six open strings of a guitar can be tensioned to the series as calculated from thickest string to thinnest string: major third, fourth, fourth, fourth, major third. If the first pitch is F, this novel series completes as A, D, G, C, E herein termed Open F. A third quality series has intervals that give B, G, C, G, C, E as the series. Fret structure devised to optimize tunings of this nature is claimed to be novel and useful.
[0013] If the Open F tuning is tensioned over the typical straight frets of a traditional guitar, a large number of full six string voicings are somewhat difficult for the human hand to finger. The various fingerings are almost universally improved by the use of multi-angle frets designed to allow a standard 0 cent tryst for the two treble strings, with a smooth progression of elevated tryst as the fret travels underneath the bass strings. Recommended values establish a tryst value of 48 cents for the sixth (bass) string loci relative to the first or second treble string loci of the fret. A straight progression for the four inner tryst values is 12 cents, 12 cents, 12 cents, and 12 cents, which add up to 48 cents tryst. If the offset fret portion is curved in an alternate embodiment, the four inner tryst values will vary (not being identical) but will by laws of nature still add up to a 48 cent tryst value collectively from the sixth to the second loci.
[0014] For further clarification not using tryst values, angles and degrees can be used to describe the above cited Open F preferred embodiment. Thus the first two treble loci would express an angle of zero degrees, whereas the third loci relative to the second and first loci would express an angle of twenty-six degrees. The fourth, fifth, and sixth loci would follow the angle expressed by the third loci. Thus the bass portion of the multi-span fret would lie closer to the traditional nut bearing end of the guitar than does the treble portion of the same fret. This is termed positive torque. Negative torque would have the bass portion of the frets further away from the guitar's nut bearing end relative to its treble portion, and is a condition not contemplated by this invention. All instant embodiments use positive torque.
[0015] The shape of the first fret is identical to the second, and the third and so forth. These identically shaped frets converge closer and closer to each other on the neck moving away from the nut end, losing about 5.4% of the separation distance at each stage. This shortening of fret separation is a long described art. Locked fret loci is maintained because the strings are the same length and the nut and bridge are shaped to mimic the shape of the parallel frets. Otherwise an undesirable disruption of intonation would appear. In this paper a nut is considered the “zero” fret, because it represents the longest graduated point of a string's vibration farthest away from the bridge end.
BRIEF DESCRIPTION OF DRAWINGS
[0016] [0016]FIG. 1 shows the preferred embodiment of multi-angle frets on a guitar neck.
[0017] [0017]FIG. 2 shows the preferred embodiment of multi-angle frets in close-up.
[0018] [0018]FIG. 3 shows an alternate embodiment of multi-angle frets in close-up.
[0019] [0019]FIG. 4 shows another alternate embodiment of multi-angle frets in close-up.
[0020] [0020]FIG. 5 shows the improvement in fingering ease for a typical Open F chord.
[0021] [0021]FIG. 6 shows an alternate embodiment using some non-contiguous fret loci.
[0022] [0022]FIG. 7 shows another alternate embodiment using non-contiguous fret loci.
[0023] [0023]FIG. 8 shows another alternate embodiment using contiguous fret loci.
DETAILED DESCRIPTION OF THE INVENTION
[0024] [0024]FIG. 1 shows a treble string 1 held at tension between tuning keys (not shown) of a headstock 2 passing over nut 3 along fretboard 4 and over soundhole 5 before termination at bridge 6 . The first two frets passed over are first fret 7 and second fret 8 and eventually twelfth fret 9 . No more than twelve frets are illustrated as more are not required to convey the teaching. For a typical bass guitar, the two bassmost strings would not be depicted.
[0025] [0025]FIG. 2 shows a blowup of the instrument of FIG. 1. Scale markings 10 , 11 , and 12 illustrate the setback distance of an imaginary vertical fretline directly under marking 10 which also passes through the fret loci where treble string 1 is sounded at fret 8 . On this same fret, the horizontal distance measured to the actual fret loci sounding the largest bass string would flat the perceived pitch about 50% of the cent value it would sound on an equal temperament guitar with actual vertical frets. The actual fret loci of this bass string is at a vertical point under marking 11 . This is comparative as 50% of the auditory distance to the imaginary vertical fretline directly under marking 12 which also passes through the fret loci where treble string 1 is sounded at fret 7 . It should be noted that 50% of the auditory distance is not the same as 50% of the physical distance shown. A flatting of 50 cents tryst is somewhat less than the physical midpoint. The teaching reveals that the six fret loci of fret 7 and the six loci of fret 8 are equidistant for any given string, a condition termed locked fret loci where the six strings are of the same open sounding length. This is only achieved by parallel frets. The facing edge of nut 3 on headstock Z is configured to mimic the path of the frets. If the hashed lines are considered 0 (zero) degrees vertical, relative to this the average string path is therefore 90 degrees. Even if the bassmost four loci of any particular fret could be connected by a curved line (not shown) rather than a straight line (as shown), the mean angle radiating away from the zero degree reference angle servicing the two treble-most loci and the bass-most sixth fret loci would still be about twenty six degrees. Thus curved fret loci are clearly better described by deviations of tryst rather than with degrees.
[0026] [0026]FIG. 3 shows an alternate embodiment where the bass end of second fret 13 and first fret 14 are still at a 50 cent tryst value relative to the treble end. However the vertical portion of these frets has been lengthened such that the three treblemost loci are all at 0 cent tryst values. Nut 15 is also configured to have its third string slot loci mimic the path of the frets. In this embodiment, the slope of the active bass section of all frets is larger. Thus this angle is widened to about 30 degrees from vertical to maintain a 50 cent tryst value. If a lower cent tryst value were acceptable, the angle could stay at 26 degrees and the string six tryst value would be about 45 cents.
[0027] [0027]FIG. 4 shows an alternate embodiment where the lowest bass portion of first fret 16 is still at a 50 cent tryst value relative to the two treblemost loci of the fret. As in the embodiment of FIG. 1 the two treblemost loci serve as a 0 cent tryst reference. However to show the variability that can be engineered into the multi-angle frets, the loci under strings three and four are lying on a portion of fret that has been engineered to also run parallel to the treble reference section. Thus this fret has a morphology with four distinct portions. As illustration of the variety that is possible, three portions are shown as straight with the bassmost section curved.
[0028] [0028]FIG. 5 shows the practical utility of angling a section of the frets from vertical with Open F tuning. The fingering for a voicing for an open A major triad chord is shown. The lower depiction shows a typical prior art guitar fretboard with straight vertical first fret 17 exactly beneath the bass most portion of first fret 18 of the upper guitar. Thus, the bass string loci of both instruments are in vertical alignment. The physical distance on the upper instrument between finger position 19 and finger position 20 is much less than that between finger position 21 and finger position 22 of the lower prior art instrument. This is the difference between a comfortable fingering and a difficult one, and is best seen by utilizing vertical hashed lines 23 and 24 as references. With typical guitars, the eliminated distance from finger position 21 and line 24 is a horizontal separation of over 1.5 centimeters. Due to the cylindrical nature of fingers, the multi-span morphology of the instant frets allows an optimized placement of fingertips recommended to be useful for many chords including the A major triad chord depicted. The first and fifth strings are sounded at the open sounding length.
[0029] [0029]FIG. 6 shows an alternate embodiment where the bass region 25 of a fret is totally separated from the treble region 26 . Both regions 25 and 26 are in vertical alignment with each other, and are both non-contiguous with the fret region 27 holding the contact loci for the third most-treble string. The zero fret 30 has a shape mimicking the shape of the other frets. The utility of this structure is evident when the strings are tuned to the low to high series D, F#, D, G, B, E. With an index finger making a barre though position 28 to allow the sounding of three pitches, the middle finger can comfortably set at position 29 while the ring finger and little finger complete a typical major chord. In point of fact, this illustrated fingering would sound a D# major chord. If position 29 was vertical with the ring finger position on the highest string, which it is not, it would reprise the contortion evident with a typical guitar making a typical barre D# formation. The value of this fret structure is the elimination of this awkward fingering for D# major, then E major, then F major, etc. as the barre chord ascends the neck. On a common guitar with vertical straight frets, this chord formation is rarely used because it is so difficult to finger.
[0030] [0030]FIG. 7 shows an alternate embodiment where the bass and treble regions are non-contiguous with the fret region 31 holding the contact loci for the fourth most-treble string. The utility of this structure is evident when the strings are tuned to the low to high series B, G, C, G, C, E. With the index finger as before making a barre behind the first fret to allow the sounding of three pitches, the middle finger can comfortably be placed at position 32 while the ring finger and little finger complete a major chord. In point of fact, this illustrated fingering would sound a G# major chord. Without the off-set fret loci as indicated, this fingering would be harder to attain.
[0031] [0031]FIG. 8 shows an alternate embodiment having both of the off-set fret loci of FIGS. 6 and 7, but combined in a way to allow a guitar of this configuration to be tuned to either Open D major or the tuning of FIG. 7. Thus fret region 33 spans two fret loci. For contrast, the entire fret is contiguous.
SUMMARY
[0032] The use of intact frets spanning the vertical regions of the fretboard or neck as in FIGS. 2, 3, 4 , and 8 is preferred, but the non-contiguous fretting structure as shown in FIGS. 6, and 7 can be employed. In the same way, the use of one multi-angle contiguous fret in the preferred embodiment of FIG. 2 could be avoided by leaving two non-contiguous frets not in a perfect line with each other but tracking along their own route. Thus each partial fret would service either four or two string loci each. However, for smooth string bending it is advised to leave the two fret portions connected as depicted. The frets in FIGS. 6 and 7 are shown non-contiguous only as an example, since in a preferred design as in FIG. 8 the separated ends exist as one long fret with a bulging hump to provide the desired offset loci.
[0033] In all instant embodiments, one or all of the offset loci deliver a desired flatting ability holding a tryst cent value equal to or greater than 10 cents. Also as stated earlier, all embodiments have offset loci placed in a position of positive torque. A plurality of these frets as described in the previous two sentences, and placed on the playing surface of the neck of a stringed instrument define the generalized structure of the instant invention.
[0034] Two mechanisms to determine the precise structure of the various preferred and alternate embodiments have been given. One utilizes a tryst value, which is a measurement of flatting in cents relative to a vertical reference. The other mechanism cites a degree of angle relative to a zero degree vertical reference. Using either tryst or slope degree, the various possible combinations are myriad when expressed as deviations to the cited values. The variations are extensive whether using curving frets, straight frets, or disjointed non-contiguous sections of fret designed to service one fret location for one given string. It is the relationship of the six loci to each other that actually define the morphology of the fret. It should be clear that a straight line will not pass through all six loci of the instant multi-angle fret, discounting any curvature of the surface of the fretboard's playing surface.
[0035] It is the many diverse open chords allowed that make the Open F tuning outstanding. When a barring technique is used, the sloping or angle of the bass portion of the multi-span frets does not extinguish or hamper a clean sounding of the pitches. The merit of the invention is further confirmed when a plurality of voicings are studied beyond the example chord shown in FIG. 5.
[0036] New instruments crafted to the invention are optimal, but modifications are possible for existing prior art fixed pitch fretted instruments. Retrofitting them to empower them to provide the described pitches are possible by refretting the existing fretboards, or refitting them with entirely new fretboards crafted to the invention. Though six strings are cited, four or five stringed instruments can also use the instant invention. The instant drawings will teach this with the bass-most strings removed.
[0037] The invention may also be considered as a nut, which in effect is a fret where the loci are in constant contact with the corresponding strings. Thus to call the invention a multi-angle fret or multi-angle nut is entirely appropriate, because the nut should express the same loci orientation as the frets to maintain locked fret loci, which is highly desirable. It has been shown in the illustrations that in these cases the nut must maintain the morphology of the associated fret to provide the proper utility.
[0038] The use of parallel frets of like demeanor is recommended together with the common practice of using strings of identical open length. However, non-parallel settings of the multi-angle frets to host unequal string length are contemplated by the inventors as a lesser embodiment. Either way, it is the particular offsetting of the treblemost strings relative to the bassmost string, and the gradualized slope or angle of the fret loci in between which establishes the intent of this instant invention. With strings of different open sounding length, when the frets are fitted along the neck there would by necessity be a need for a slight divergence of angle (relative to each other) for the non-parallel frets to follow acoustical law. For example with a nut-to-bridge distance of 62 centimeters for the other three treble strings, if bass string six is longer by 2 centimeters, string five by 1.5 centimeters, and string four by one centimeter, the shape of the twelfth fret would still be as in FIG. 1. But the sixth loci of the nut would flare out to about a 54 cent tryst value, and each fret would have an intermediate value on the bass loci diminishing down to the desired 48 cent tryst at fret twelve (changes too subtle for the illustration to convey). The test of a given instrument with unequal string length is if the strings are reduced to a common length, the frets as initially given with the test instrument will reveal as corrected values (when flatted by acoustical law to locations sounding the same pitches as before) either a set of tryst values as contemplated by this invention or they will not. In this test the twelfth fret's shape is unaltered.
[0039] This invention should not be confined to the embodiments described, as many modifications are possible to one skilled in the art. This paper is intended to cover any variations, uses, or adaptations of the invention following the general principles as described and including such departures that come within common practice for this art and fall within the bounds of the claims appended herein. | A particular fret and nut morphology for tone generation of stepped pitch stringed instruments such as guitar is described. The use of parallel multi-angle frets having a plurality of angles enables better fingerings for cited alternate six string tunings other than provided by common Barre F tuning; E, A, D, G, B, E. Guitars that employ various alternate tunings are shown to be more practical and efficient with the instant multi-angle fret arrangement than the fingerings available with traditional vertically straight frets. The instant embodiment uses positive torque exclusively for an offset region of the multi-angle fret or nut. | 6 |
FIELD OF THE INVENTION
This invention relates to methods for producing micro-optical structures, for use as optical elements, such as lenses and gratings, with arbitrary (essentially any) surface-relief profile and, if desired, with optomechanical alignment marks.
Briefly, the invention is carried out by varying the exposure dose, spatially, based upon predetermined contrast curves of a low-contrast photosensitive material. Arbitrary one-dimensional (1-D) or two-dimensional (2-D) surface contours including spherical, aspherical, toroidal, hyperbolic, parabolic, and ellipsoidal can be achieved. The final medium for the fabricated microstructures can be a wide range of materials through the use of etching and replication technology. The method is adapted to mass production. Applications for this invention include, but are not limited to, and particularly the manufacture of microstructures for use in the fields of optical communications, optical data storage, optical interconnects, telecommunications, and in displays, and focal-plane arrays.
This invention is related to the invention described in U.S. patent application, Ser. No. 09/0905,300, filed Jun. 10, 1998 now U.S. Pat. No. 6,075,650, issue Jun. 13, 2000.
BACKGROUND
A microlens or microcylinder imparts a given phasefront to incident radiation. Similar to macroscopic optical systems, these micro-optical elements can focus incident radiation, diverge the radiation, as well as impart a phase function to correct aberrations from previous elements in the system, or precorrect for aberrations occurring downstream of the microelements. There are numerous methods of fabricating surface-relief micro-optics, and these include multi-step mask and etching, resist thermal transport, e-beam exposure, laser ablation, stamping, etc. The present invention offers advantages over all of these described processes, due to the precision control one has over the final surface shape of the micro-optical element, and in providing optical microstructures having profiles with heights exceeding 15 μm (microns) which in lenses is called a deep sag.
Previous methods of fabrication of elements using exposures of photoresist either concentrated upon fabricating binary (two-level) structures, such as in the case of micro electro-mechanical systems (MEMS), or exposed photoresist to a varying dosage of exposure radiation using thin photoresist. Photoresist has been exposed to create continuous-relief photoresist profiles of optical devices (e.g., microlenses, diffractive phase plates, and diffraction gratings). Exposure methods have included laser pattern generation, see, T. R. Jay and M. B. Stern M. T. Gale, M. Rossi, J. Pedersen, H. Schütz, “Fabrication of continuous-relief micro-optical elements by direct laser writing in photoresist,” Opt. Eng . 33, 3556-3566 (1994), grayscale mask exposures, see, H. Andersson, M. Ekberg, S. H{dot over (a)}rd, S. Jacobsson, M. Larsson, and T. Nilsson, “Single photomask, multilevel kinoforms in quartz and photoresist: manufacture and evaluation,” Appl. Opt . 29, pp. 4259-4267 (1990); D. C. O'Shea and W. S. Rockward, “Gray-scale masks for diffractive-optics fabrication: I. Commercial slide imagers,” Appl. Opt . 34, 7507-7517 (1995); D. C. O'Shea and W. S. Rockward, “Gray-scale masks for diffractive-optics fabrication: II. Spatially filtered halftone screens,” Appl. Opt . 34, 7518-7526 (1995); W. Daschner, P. Long, R. Stein, C. Wu, and S. H. Lee, “Cost-effective mass fabrication of multilevel diffractive optical elements by use of a single optical exposure with a grayscale mask on high-energy beam-sensitive glass,” Appl. Opt. 36, 4675-4680 (1997), and holographically, M. C. Hutley, “Optical techniques for the generation of microlens arrays,” J. of Mod. Opt . 37, 253-265 (1990); H. Ming, Y. Wu, J. Xie, and Toshinori Nakajima, “Fabrication of holographic microlenses using a deep UV lithographed zone plate,” Appl. Opt . 29, 5111-5114 (1990). But the present invention overcomes limitations of prior processes in affording arbitrary micro-structure profiles, especially with heights (sag in case of lenses) exceeding 15 μm.
In the multi-step mask and etch process, as described in M. B. Stern, “Chapter 3: Binary Optics Fabrication,” in Micro-Optics: Elements, Systems, and Applications , ed. H. P. Herzig, (Taylor & Francis, Bristol, Pa., 1997), pp. 53-85, one exposes a photosensitive material (typically photoresist developed for the semiconductor industry) using a binary amplitude mask. This mask consists of a series of optically opaque and clear features (e.g., Chromium on glass) that is used to selectively expose selected areas of a photoresist-coated substrate to electromagnetic radiation. After development, one achieves a binary structure in the photoresist that can be transferred into the underlying substrate material through an etching process. This exposure, development and etching process can be repeated with a series of different photomasks in order to achieve a multi-level surface-relief pattern. Although of practical use for the fabrication of diffraction gratings and phase plates, the multi-step masks and etch process has disadvantages when the fabrication of deep-sag or high numerical aperture (NA) micro-optical elements is required. For a diffraction grating fabricated with a multi-level process operating at the order m, the maximum theoretical diffraction efficiency (η m ) attainable is given by η m = sin c 2 ( m / p ) = [ sin ( π m / p ) π m / p ] 2 , ( 1 )
where p is the number of levels of the structure. Therefore, one notes that if a structure is blazed for 1 st order (phase depth of 2πn and constructed with 16 levels, the diffraction efficiency one can theoretically achieve is 98.7%. Likewise if a structure is blazed for 2 nd order (phase depth of 4π) and constructed with 32 levels, the diffraction efficiency one can achieve is also 98.7%. In other words, if a multi-level profile is such that each level represents π/8 phase, the efficiency is 98.7%. Similarly, if each level of the structure translates to π/4 or π/2 phase, the efficiency drops to 95.0% and 81.1%, respectively. To first-order, one can determine the efficiency of a multi-level microlens structure using Eq. (1) for a diffractive structure. For a surface-relief structure with a refractive index of 1.5 operating at the telecommunications wavelength of 1.3 μm, a physical depth of 2.6 μm corresponds to a phase depth of 2π according to φ = 2 π λ d ( n - 1 ) , ( 2 )
where φ is the phase depth, d is the relief depth, λ is the operating wavelength and n is the index of refraction of the substrate material (air is assumed to be the second medium). Therefore, if one has a microlens that requires a sag of 10.4 μm, the phase depth is 8 μn. With a 16-level structure, the element will only be 81% efficient at best (assuming no fabrication errors).
Such a microlens with additional levels in order to increase the optical efficiency, is impractical to attain. For a 99 percent efficient f/3 microlens operating at λ=1.3 μm, the critical dimension (CD) of the surface features required is approximately 0.5 μm. This CD offers an extreme challenge in terms of achieving such features, let alone the mask-to-mask alignment tolerances required (generally one quarter of the CD). Since microlenses required for telecommunications and optical data storage can require f/2 and f/1 optical speeds, the use of multi-level mask and etch technology is therefore impractical for achieving the majority of the optical elements required.
Laser pattern generators, which have been proposed, have emphasized the production of binary masks. See, for example, S. Charles Baber, “Application of high resolution laser writers to computer generated holograms and binary diffractive optics,” Holographic Optics: Optically and Computer Generated , SPIE Proc.1052 66-76 (1989); E. Jäger, J. Hoβfeld, Q. Tang, T. Tschudi, “Design of a laser scanner for kinofrom fabrication,” Holographic Optics II: Principles and Applications , SPIE Proc. 1136, 228-235 (1989). Laser pattern generators for making diffractive kinoforms are described in M. T. Gale, M. Rossi, J. Pedersen, H. Schütz, “Fabrication of continuous-relief micro-optical elements by direct laser writing in photoresist,” Opt. Eng . 33, 3556-3566 (1994).
Laser pattern generators have been proposed to expose photoresist in a point-by-point fashion with variable exposure doses, see, for example, M. T. Gale, M. Rossi, J. Pedersen, H. Schütz, “Fabrication of continuous-relief micro-optical elements by direct laser writing in photoresist,” Opt. Eng . 33, 3556-3566 (1994) to achieve continuous-relief microstructures. Likewise, proposed has been the use of grayscale mask lithography to produce continuous-relief profiles in photoresist, see Vlannes, U.S. Pat. No. 5,004,673; G. Gal, U.S. Pat. No. 5,310,623, and a U.S. Pat. No. 5,482,000 to G. Gal.
The present invention improves upon prior LPG methods even for the fabrication of diffractive elements, by patterning of photoresist with a blazed multi-level or continuous profiles and with depths exceeding 15 μm. Prior to the present invention, no one had fabricated continuous-relief microlenses using a variable exposure dosage that resulted in microstructures with surface sags exceeding 15 μm.
Using thermal transport mechanisms to fabricate micro-optical components, one takes a pre-patterned surface relief structure, and through the introduction of heat above the thermal glass transition temperature of the material (T g ) the structure is melted into a spherical or cylindrical profile by surface-tension effects. Initially most thermal transport work was performed with binary patterned photoresist, as described in Z. D. Popovic, R. A. Sprague, and G. A. Neville Connell, “Technique for monolithic fabrication of microlens arrays,” Appl. Opt . 27, 1281-1284 (1988); D. Daly, R. F. Stevens, M. C. Hutley, and N. Davies, “The manufacture of microlenses by melting photoresist,” Meas. Sci. Technol . 1, 759-766 (1990). One first exposes a substrate with photoresist, and through a binary high-contrast exposure process, patterns the photoresist into a series of cylindrical surface-relief structures. By heating the substrate using a convection oven or hot plate the photoresist can be melted. Due to surface tension, the resulting melted profile takes the form of a spherical surface. This process is conducive to the fabrication of microlenses in the f/1 to f/3 range, and is not conducive towards slower microlenses due to the tendency of the melted photoresist to sag in the middle.
The continuous-relief profile of the photoresist can be transferred into the underlying substrate material through a dry etching process, see, E. J. Gratrix, “Evolution of a microlens surface under etching conditions,” Proc. SPIE 1992, pp. 266-274 (1993); M. B. Stern and T. R. Jay, “Dry etching for coherent refractive microlens arrays,” Appl. Opt . 33, pp. 3547-3551 (1993). In recent years, more sophisticated methods of producing microlenses through the thermal transport scheme have been proposed. Hlinka et al, U.S. Pat. No. 5,718,830 proposed using photoresist masking and RIE etching to produce cylindrical islands in a PMMA layer that is spun onto a substrate. These cylindrical islands are then melted in order to produced the desired microlens in PMMA. A similar concept was filed in 1994 (Iwasaki et al, U.S. Pat. No. 5,298,366) that covered the use of an intermediate layer in order to transfer the cylindrical islands into a final material other than photoresist. This second material could then be thermally reflowed in order to produce the desired microlenses. Feldblum et al, U.S. Pat. No. 5,286,338 realized the deficiency of the thermal transport mechanism to produce microlenses with precision surfaces for diffraction-limited optical performance, and proposed the use of reactive ion etching to rectify the situation. One can take resist microlenses with precision surfaces for diffraction-limited optical performance, and proposed the use of reactive ion etching to rectify the situation. One can take resist microlenses produced using the thermal transport mechanism, and etch-transfer them into the underlying substrate using reactive ion etching (RIE). By changing the gas constituency of the RIE chamber during etch-transfer, one can change the etch selectivity (ratio of substrate etch rate to photoresist etch rate), and thereby modify the profile of the resultant microlens to be closer to the desired profile than the thermal transport method alone can achieve.
Another method which has been proposed for improving the profile obtained by the thermal transfer method involves preshaping the microlens structure before melting have been implemented, including multistep, as described in D. Daly, R. F. Stevens, M. C. Hutley, and N. Davies, “The manufacture of microlenses by melting photoresist,” Meas. Sci. Technol . 1, 759-766 (1990), and laser pattern generation, as described in T. Jay and M. Stern, “Preshaping photoresist for refractive microlens fabrication,” Opt. Eng . 33, 3552-3555 (1994). Once preshaped, the photoresist structure is then melted to smooth the surface-relief profile.
Researchers have also patterned non-photoresist materials such as InP. GaAs, and GaP, using the thermal transport method as described in Z. L. Liau, V. Diodiuk, J. N. Walpole, and D. E. Mull, “Large-numerical-aperture InP lenslets by mass transport,” Appl. Phys. Lett. 52, 1859-1861 (1988); Z. L. Liau, D. E. Mull, C. L. Dennis, R. C. Williaamson, and R. G. Waarts, “Large-numerical-aperture microlens fabrication by one-step etching and mass-transport smoothing,” Appl. Phys. Lett . 64, 1484-1486 (1994); J. S. Swenson, Jr., R. A. Field, L. Mitt. Abraham, “Enhanced mass-transport smoothing of f/0.7 GaP microlenses by use of sealed ampoules”, Appl Phys. Lett. 66 1304-1306 (1995). For the non-polymer materials, one requires several days of a controlled heating processes in special atmospheres wherein oven temperatures can reach 1000° C. For the photoresist-melting method of fabricating microstructures, the temperatures are generally in the 160-200° C. The transfer of the continuous-relief profile of the photoresist can be transferred into the underlying substrate material through a dry etching process, see, E. J. Gratrix, “Evolution of a microlens surface under etching conditions,” Proc. SPIE 1992, pp. 266-274 (1993); M. B. Stern and T. R. Jay, “Dry etching for coherent refractive microlens arrays,” Appl. Opt . 33, pp. 3547-3551 (1993).
A disadvantage of the thermal transport mechanism is the ability to achieve microlens arrays with a high filling factor (ratio of area taken up by the optical elements to the total area of the substrate). One requires a space between the patterned pillar area of the resist, PMMA, or other material in order for distinct structures to be defined that can be melted into shape. If the filling factor is less than 100%, this can reduce the overall efficiency of the optical system. One solution proposed by Aoyama and Shinohara, in U.S. Pat. No. 5,694,246 is to first pattern a sparse array so that the separation of microlenses is twice a given microlens diameter. After melting and fixing the material, the sparse microlens array is recoated with photoresist and patterned with a second sparse array, but this one aligned such that the cylindrical islands of the second array are positioned between the gaps of the microlenses of the first array. The second array, is then reflowed in order to produce a single microlens array with close to 100% filling factor. The disadvantages of the method proposed by Aoyama and Shinohara are the extra processing steps, and the additional precision one requires in aligning one array to a second one.
A principal disadvantage of the thermal transport method is the lack of control that one has regarding the surface-relief profile. Since the final processing step involves a thermal reflow, the shape and quality of any alignment marks simultaneously patterned onto the surface is severely limited. Therefore, sharp registration features with submicron accuracies have not been achieved.
The invention also allows for microstructures to have filling factors up to 100% without any additional processing steps. The invention enables one to simultaneously pattern alignment or registration marks. With the thermal reflow method, the shape and quality of any alignment marks simultaneously patterned onto the surface is severely limited. Therefore, sharp registration features with submicron accuracies are not possible using this thermal transport technique.
Other methods of producing microlenses have concentrated upon fabricating a microlens directly onto an optical fiber (see, for example, Edwards et al, U.S. Pat. No. 5,011,254, and Modavis and Webb, U.S. Pat. No. 5,455,879). These techniques typically involve drawing the end of the fiber, or otherwise tapering it in such a manner as to produce a surface capable of at least partially collimating or focusing the radiation being emitted by the fiber. The invention described herein does not relate to such structures. Rather it relates to a microstructured substrate that is independently fabricated (but then may be integrated onto the end of a fiber if required). The preforming of glass has been proposed to create stand-alone glass microcylinders. Snyder and Baer, U.S. Pat. No. 5,155,631, describes preforming glass such that a cylindrical lens is produced of arbitrary curvature. This cylindrical lens can be integrated into an optical system in order to collimate laser diode arrays. The present invention differs from the process described by Snyder and Baer, in that the present invention does not involve the use of heat to preform materials, and is not limited to cylindrical microstructures.
It has been proposed to use grayscale contact prints or projection printing to fabricate microstructures in photoresist. See, H. Andersson, M. Ekberg, S. H{dot over (a)}rd, S. Jacobsson, M. Larsson, and T. Nilsson, “Single photomask, multilevel kinoforms in quartz and photoresist: manufacture and evaluation,” Appl. Opt . 29, pp. 4259-4267 (1990); D. C. O'Shea and W. S. Rockward, “Gray-scale masks for diffractive-optics fabrication: I. Commercial slide imagers,” Appl. Opt . 34, 7507-7517 (1995); D. C. O'Shea and W. S. Rockward, “Gray-scale masks for diffractive-optics fabrication: II. Spatially filtered halftone screens,” Appl. Opt . 34, 7518-7526 (1995); W. Daschner, P. Long, R. Stein, C. Wu, and S. H. Lee, “Cost-effective mass fabrication of multilevel diffractive optical elements by use of a single optical exposure with a grayscale mask on high-energy beam-sensitive glass,” Appl. Opt . 36, 4675-4680 (1997). See also, M. C. Hutley, “Chapter 5: Refractive Lenslet Arrays,” in Micro-Optics: Elements, Systems, and Applications , ed. by H. P. Herzig, (Taylor & Francis, Bristol,. Pa., 1997), pp. 127-150. The grayscale masks can also be produced using photographic slide film or through the use of high-energy beam sensitive (HEBS) glass plates. But such proposals have not been practical when micro-structure with arbitrary profiles and especially height or sags exceeding 15 μm are needed.
SUMMARY OF THE INVENTION
The fabrication method provided by the current invention enables the direct patterning of photosensitive material in accordance with a variable dose of electromagnetic radiation. The photoresist coating, exposure, and development process enable one to create surface-relief profiles of arbitrary surface micro-structure. The previous methods described above have not provided optical micro-structures having the arbitrary relief profiles and, if desired, with alignment and registration marks capable of the fabrication process of the present invention. The invention enables to the use of low-contrast photosensitive material to achieve a final structure (replicated, etch-transferred, etc.) that has a profile height (surface sag) greater than 15 μm.
In accordance with the present invention, photosensitive material is exposed to a spatially variable dose of electromagnetic energy to create a surface-relief structure upon development of the photosensitive material. The photosensitive material may be coated, onto a substrate of interest (planar or otherwise). The coating is characterized by its response curve in terms of developed relief depth to electromagnetic exposure energy and wavelength.
The invention involves the recognition that the response curve is a complex function of the material parameters as well as the method with which the coating, exposure, and development process steps are performed. For instance, the material's viscosity, in conjunction with the coating parameters (spin speed in the case of spin-coating, pull rate in the case of dip coating, etc.), will dictate the final film thickness. During exposure, the wavelength of the radiation used, in conjunction with pre-exposure procedures (such as the temperature and duration of an oven bake), complex index of refraction of the photosensitive material, and chemical compound of the material being exposed, are parameters that will dictate the sensitivity of the material, and therefore rate of development. Development procedures can also vary the response curve. Development time and development solution used also affect development rates, but so will the exact method of development. In the case of aqueous development, the response curve will change if one uses immersion, spray, or puddle methods of developing the photosensitive material. The invention is carried out by selecting, the photosensitive materials and controlling the coating, exposure, and development parameters, to achieve the precision microstructures desired.
The resulting microstructure in the photosensitive material can remain in the material, or be etch-transferred into the underlying substrate. The microstructure can also be replicated into a polymer material via a cast-and-cure, embossing, compression molding, or compression injection molding process. This enables mass production of the optical micro-structures. The disclosed manufacturing process is robust in that arbitrary surface-relief structures can be fabricated that have optical and mechanical properties of interest. Optical micro-structures of particular interest include microlenses with toroidal, elliptical, and hyperbolic surface-relief structures.
Preferably, laser pattern generation (LPG) is practiced in-accordance with this invention. One exposes photoresist using a single or multiple focused laser beam that rasters across a photosensitive substrate. There are two scanning geometries that are generally preferred: x-y scanning, where the substrate is moved on a pair of orthogonal linear stages, and r-θ scanning, where the substrate is spun on an air bearing spindle. In the x-y scan systems, the part is scanned below a single or multiple focused laser beams. For photoresist that is sensitive in the blue or UV portions of the electromagnetic spectrum, the radiation source used is typically an argon-ion, krypton-ion, or helium-cadium laser. Semiconductor laser diodes may be used for LPGs. The invention is not limited to the source of exposure energy and other sources of electromagnetic radiation such as the LED or electron beams may be used, lasers however are now preferred. To spatially vary the exposure dose the photosensitive material is exposed to, one can vary the speed of the stages moving the focused exposure beams or the substrate. This changes the dwell time of the exposure beam. A more accurate method of controlling the exposure dosage is to vary the intensity of the writing beam or beams. Methods for accomplishing this include the use of an electro-optic or acousto-optic modulators with diode lasers, including those which may provide radiation in the blue or UV portion of the electromagnetic spectrum, the drive current of the laser can be directly modulated to vary the outputed laser beam's power. A computer desirably is used to control the modulator and computes, based upon the desired surface-relief pattern and the response curve of the photosensitive material, the modulation sequence required. After the relief pattern has been developed, the element can be used as is, or one can transfer the desired pattern into the substrate using an etch process. The patterned surface can also be used as the master element for a replication process.
With the gray-scale mask lithography method, practiced with this invention, one can expose photoresist using a mask with a transmission function T(x,y). By passing a beam of uniform or well-defined intensity variation I inc (x,y) through this mask, the transmitted beam can have a controlled intensity function I out (x,y)=I inc (x,y) T(x,y). The intensity function can be used to expose photoresist, or any other photosensitive material once one has a well-characterized response curve for the material.
Other exposure methods of capitalizing upon this invention include the use of moving apertures and controlled diffraction effects in order to achieve the surface-relief profiles desired. With the moving aperture method, an amplitude mask is translated in front of an electromagnetic exposure beam. By choosing the amplitude distribution of the mask and the path with which the mask and/or substrate is being translated, one can control the spatial distribution of the exposure dose for a particular photosensitive material.
Another method of achieving desired surface-relief profiles is to expose a photosensitive material to the intensity of a diffracted electromagnetic (such as an optical) beam. The diffraction profile can be achieved by controlling the temporal and spatial coherence of the exposure beam, controlling the aperture shape the radiation is diffracting around, as well as the distance from the aperture the photosensitive material is set at. For instance, one can diffract or focus a beam through a pinhole in order to create an exposure dosage that is circularly symmetric but decreases radially. By tailoring the exposure profile to the response curve of the photosensitive material (and vice-versa) one can then write and develop a microlens structure. One can then translate the substrate underneath the radially symmetric exposure dose in order to achieve a cylindrical microlens.
The current invention allows one to expose arbitrary profiles. Once the response curve of a photosensitive material is characterized, then the exposure methods, such as mentioned above may be used to create the relief structures dictated by a particular optical or mechanical design. For optical applications, phase formats of interest include radially symmetric profiles, as well as non-rotationally symmetric profiles. Ray tracing programs such as Optical Research Associate's (ORA's) Code V and Sinclair Optics OSLO SIX, have different conventions in terms of how the phase of a diffractive optical element (DOE) is represented, so only the conventions used by Code V will be given for illustrative purposes. For rotationally symmetric phase plates, the phase polynomial φ (r)can be represented by
φ(r)=c 1 r 2 +c 2 r 4 +c 3 r 6 +c 4 r 8 + (3)
To better relate such a rotationally symmetric phase profile to that of a conic constant, Code V also allows for input of the phase function according to φ ( r ) = cr 2 1 + 1 - ( 1 + k ) c 2 r 2 + Ar 4 + Br 6 + Cr 8 + … , ( 4 )
where k is the conic constant, and c is the curvature at the pole of the surface. For a pure conic surface, the coefficients A, B, C, etc. are zero. For a sphere, k=0, for a hyperboloid, k<−1, for a paraboloid, k=−1, and for an ellipsoid, −1<k<0.
For non-rotationally symmetric profiles, one can describe the phase function required using
φ(x,y)=c 1 x+c 2 y+c 3 x 2 +c 4 xy+c+c 5 y 2 + (5)
Equations (3) through (5) represent the standard phase inputs of Code V that any arbitrary phase function can be fit to. For instance, one may desire a phase function that has Zernike polynomials added to the phase structure in order to improve the micro-optical element's tolerance to alignment errors. Other phase terms can be added to the relief profile that act to compensate or pre-compensate for other elements in the optical system. In addition to describing the phase of the optical element, one can separately define in a more graphical way alignment or registration marks that are probed interferometrically, mechanically, or through optical imaging in order to align the micro-element.
The manufacturing process provides benefits for telecommunications and optical data storage by enabling the fabrication of optical elements for optical interconnects and for communications.
BRIEF DESCRIPTION OF DRAWINGS
The foregoing and other objects, features and advantages of the invention will become more readily apparent by reference to the following detailed description when considered with the accompanying drawings, wherein:
FIGS. 1 ( a ) and ( b ) are schematic diagrams o systems for optical data storage and optical telecommunications, FIG. 1 ( a ) illustrating a fiber-to-fiber coupler, while FIG. 1 ( b ) illustrates a micro optical system for collimating and circularizing a beam from a semiconductor diode laser.
FIG. 2 ( a ) is a schematic diagram illustrating the geometry of microlenses with spherical and hyperbolic surface-relief profiles, and FIG. 2 ( b ) is a graph which illustrates the surface sags required for specific NAs and diameters.
FIGS. 3 ( a ), ( b ) and ( c ) are schematic diagrams of the steps involved in fabricating a microstructure using the inventive process hereof, both in photoresist and in masters to make microlenses in mass production, (FIG. 3 ( a )), FIGS. 3 ( b ) and ( c ) illustrate the steps which are used in high volume production.
FIG. 4 is a schematic diagram which illustrates the spin-coating method of coating a photosensitive material.
FIGS. 5 ( a ) and ( b ) depict spin coating curves for Shipley 1075 photoresist and SU8 photoresist respectively. The curves represent the photoresist film thickness as a function of rpm of the spin coater.
FIGS. 6 ( a ) through ( e ) are diagrams of a several coating steps which may be used in practicing the invention; meniscus coating, dip coating, vacuum coating, electroplating, and spray coating processes being illustrated in FIGS. 6 ( a ) through 6 ( e ), respectively.
FIG. 7 is a schematic diagram of a laser pattern generator used for the exposure of photosensitive material in accordance with the invention.
FIGS. 8 ( a ) and ( b ) are schematic diagrams which depict a mask aligner and a projection exposure system in FIGS. 8 ( a ) and 8 ( b ), respectively. These systems can be used for the exposure of a photosensitive material to a variable dosage of electromagnetic radiation across the substrate.
FIG. 9 is schematic diagram which depicts the step of exposing photosensitive materials to with a spatially variable electromagnetic exposure dosage through the use of rotating masks, in accordance with an embodiment of the invention.
FIGS. 10 ( a ) through ( c ) illustrate several steps for developing a photosensitive material that include puddle, spray, and dipping, which steps may be used alternatively in accordance with the invention.
FIGS. 11 ( a ) and ( b ) illustrate photoresist contrast curves that may be used to achieve arbitrary surface-relief structures, along with several multilevel and continuous-relief profiles that allow one to achieve profiles having heights exceeding 15 μm.
FIG. 12 shows two curves of theoretical and fabricated surface profiles for a f/1 hyperbolic microlens. By comparing these curves, one can fine-tune the predicted response curve of the photosensitive material being exposed and developed.
FIGS. 13 ( a ) through ( c ) are plots of optical profilometry data for a spherical microlens fabricated by patterning photoresist with a x-y laser pattern generator in accordance with the invention.
FIGS. 14 ( a ), ( b ) and ( c ) are plots similar to those of FIG. 13 of optical profilometry data for a toroidal microlens fabricated by patterning photoresist with a x-y laser pattern generator. Such lenses are advantageous when collimating and/or circularizing anamorphic radiation sources such as a laser diode, as described in the above-referenced related patent application.
FIG. 15 illustrates microstructures with alignment marks that may be provided simultaneously in conjunction with the microstructures made with the inventive process hereof.
DETAILED DESCRIPTION
FIG. 1 illustrates some of the profiles needed by the telecommuncations industry. FIG. 1 ( a ) shows an optical design for a fiber-to-fiber coupler, and FIG. 1 ( b ) shows a micro-optical element for collimating and circulating a semiconductor laser diode. In FIG. 1 ( a ) the two fibers ( 11 ) are assumed to be identical, both having NA=0.25. The collimating and focusing microlenses ( 12 ) are identical and are rotationally symmetric, aspheric surfaces. For a diameter D of 140 μm, the surface sag of the microlenses is 20 μm. The separation distances L 1 , L 2 , and L 3 are 250 μm, and 100 μm, and 250 μm, respectively. Such a design can achieve greater than 95% coupling efficiency. In FIG. 1 ( b ) the semiconductor laser ( 13 ) emits an astigmatic beam ( 15 ) that has a full-width at 1/e 2 of 8° and 21°. The astigmatism between the fast and slow axis is 4 μm. Using the invention described by this patent, one can fabricate a two-element system, wherein each element is a toroidal surface. The first microlens ( 14 ) has a clear aperture of 120 μm and a maximum sag of 16 μm. The second microlens ( 16 ) has a clear aperture of 600 μm and a sag of 35 μm. The dimensions L 1 and L 2 for FIG. 1 ( b ) correspond to 130 μm and 4 mm, respectively. Note that since one can fabricate anamorphic microlenses of sags greater than 15 μm using this invention, one can produce the design illustrated schematically in FIG. 1 ( b ) and achieve looser alignment tolerances than current commercially available micro-optical elements. For example, circularizers sold by Blue Sky Research (Santa Cruz, Calif.) have only ±0.5 μm lateral tolerance in the fast axis of the laser, versus ±3 μm of the presented design.
FIG. 2 illustrates the geometry of microlenses with spherical and hyperbolic surface-relief profiles and illustrate the surface sags required for specific NAs and diameters. Illustrated in FIG. 2 ( a ) is a schematic of how a point source ( 21 ) can be collimated by a microlens with a spherical ( 22 ) or a hyperbolic ( 23 ) relief profile. The sag of the spherical microlens is given by sag h = f h n 1 ( n 2 + n 1 ) [ 1 + D 2 4 f h 2 n 2 - n 1 n 2 + n 1 - 1 ] , ( 6 )
where D is the diameter of the microlens and R is the radius of curvature of the spherical surface and is related to the front focal length according to
R=f s (n 2 -n 1 ) (7)
where n 1 and n 2 are the indices of refraction of the incident and transmitted media, respectively. For the hyperbolic surface, the surface sag is given by sag s = R - R 2 - ( D / 2 ) 2 , ( 8 )
where f h is front local length of the hyperbolic microlens. Note that for a given NA defined by n 1 sin θ, the sag of the hyperbola will be less than that of the spherical lens. The hyperbolic surface is advantageous since it is the optimal refractive surface for collimating (or focusing) a point source when n 2 >n 1 .
FIG. 2 ( b ) illustrates the relationship between diameter and NA for microlenses with spherical and hyperbolic surface-relief profiles for elements that have a maximum sag of 15, 25, 35, 50, and 100 μm of sag. In calculating the curves for FIG. 2 ( b ), indices of refraction of n 1 =1 and n 2 =1.5 were chosen. One notes that a spherical refractive surface is only able to attain a numerical aperture of 0.32. One also notes that the numerical aperture of a system (e.g., optical fiber or laser diode source) does not have to be very large before the surface sag required exceeds 15 μm. For example, a microlens that is only 300 μm in diameter requires a surface sag of 15 μm in order to operate at NA=0.1, and a surface sag of 25 μm in order to obtain NA=0.25. Although FIG. 2 ( b ) only illustrates examples for hyperbolic and spherical surfaces, it should be reiterated that the current invention is by no means limited to these profile shapes. The patterning of surface-relief structures with elliptical, cylindrical, and arbitrary profiles involving the use of Zernike polynomials, are but a few of the surfaces that can be achieved. The invention described by this patent allows one to fabricate such deep-sag, arbitrary profile microlenses, such that one can build and assemble micro-optical systems with the minimum amount of wavefront error.
Steps for the exposure of a photosensitive material are illustrated in FIG. 3 . One first prepares a given substrate by (Step 31 ) cleaning the surface to promote adhesion of the photosensitive material, as well as to reduce the probability of defects caused by surface contamination. The cleaning process is dependent upon the substrate in question and can involve the use of solvents, acid solutions, ozone, etc. The cleaner the environment, the less contamination the substrate will contain that may interfere with the proper production of the desired microstructures. After the cleaning process, a dehydration bake is typically performed on a hotplate or in an oven to remove any residual volatiles or water on the surface. Once the substrate surface is prepared in Step 31 , the photosensitive material in the form of a film is coated on the surface (Step 32 ). This can involve a variety of coating techniques that will discussed in more detail later. The exposure of the surface (Step 33 ) is performed based upon the contrast of the photosensitive material. In other words, experimentally in step 34 , one determines the exposure dosage required to achieve a specific response from the photosensitive material as a function of the coating parameters, the specific method of exposure, and the developing parameters. Once exposed, the photosensitive material is developed in step 35 , typically in an aqueous solution and the desired surface-relief pattern is obtained. For certain applications, the photosensitive material may be suitable as the final medium for the delivered microstructured surface. In these cases, the photosensitive material may require additional fixing (Step 36 ) in order to make the material physically more durable, as well as to make the material resistant to solvents. This may involve further oven bakes, UV exposures, or other treatments. For other applications (especially for high volume production) the final medium is a polymer. The microstructured photosensitive material, can then be replicated (Step 37 ) via a cast-and-cure process, compression molding, injection molding, or compression injection molding. This typically involves first transferring the relief-pattern of the original photosensitive material into a more durable medium. To transfer the pattern into metal, an electroforming process can be conducted. One can also etch-transfer (Step 38 ) the photosensitive material into the underlying substrate using a dry etching process such as reactive ion etching (RIE), ion milling, chemically assisted ion beam etching (CAIBE), or reactive ion beam etching (RIBE). The etched substrate can be used to create replicas as an embossing tool, or can be used as the final product itself. In this manner, although the photosensitive surface may not meet the operational requirements of a specific optical system (temperature range, optical throughput, laser damage threshold, etc.), the etch-patterned substrate (substrate materials may be GeSi, SiO 2 , ZnS, ZnSe, etc.) can. The process may continue by forming masters, and using alignment marks, sandwiching the duplicates together to form microlenses, as shown in FIG. 3 ( b ).
The manufacturing process is conducive to volume manufacturing. For telecommunications and optical data storage systems, volumes of micro-optical elements can be in the millions, so it is imperative that one can produce the desired optical elements in a cost-effective manner. The manufacturing method described by this patent relates to a method for fabricating high-precision, arbitrary surface-relief patterned masters, from which high-volume replicas can be created. FIG. 3 ( b ) illustrates a set of replication tools 38 that can be used to replicate a wafer 39 . The wafer can have a polymer coating that is embossed by the replication tools, or through a cast-and-cure method, one can achieve the desired surface-relief profiles. Once both sides of a wafer are replicated to achieve the desired micro-optical system (such as those represented by FIGS. 1 ( a ) and 2 ( b ), for example) one can dice the wafer 310 into subapertures, thereby achieving hundreds of micro-optical systems for each wafer processed. For applications that require non-polymer materials, one may pattern wafers with a multitude of optical elements, etch the entire wafer simultaneously, and then dice the wafer into components. Other variations of this wafer processing technique for high-volume applications are obvious to those skilled in the arts.
FIG. 4 illustrates how photosensitive materials can be spin-coated onto a given substrate. For illustrative purposes, we will discuss photoresists, wherein the photosensitive material is suspended in a solvent solution. Commercial spin coating machines can be obtained by such vendors as Headway Research, Inc. (Garland, Tex.) and Karl Suss America, Inc. (Waterbury Center, Vt.), and provide the best method for achieving uniform coatings (<λ/10 @ HeNe) across flat substrates. A schematic of a spin-coater is illustrated in FIG. 4. A substrate 41 is placed onto a chuck 42 that is mounted to a motor spindle 43 . The substrate is held in place by vacuum, mechanically, or by both methods. The spin-coating process itself involves a dispense stage, a spreader stage, and final spin stage. In the dispense stage, photoresist 44 is applied using a spray, a pipette 45 , or by any other means of placing a puddle of the photosensitive material onto the substrate surface. This coating process is performed either statically (the substrate being stationary) or dynamically (the substrate rotating at a slow rpm). Once dispensed, the photoresist is spun at either the final desired rpm, or is first spun for a short amount of time (approximately 5-10 seconds) at a lower rpm, and spreads out over substrate 41 in what is termed a spreading stage. This spreading stage is particularly useful for thicker photoresists to ensure that the resist is first spread across the substrate uniformly before the spinner is moved to the final rpm stage. In moving to the final rpm stage, the time of acceleration is another parameter that can be varied to make a more reliable process. To ensure proper spin uniformity, one wants to make sure that the atmosphere of the spinner bowl is saturated with vapor. In this manner inhibited drying is achieved, to help ensure that during the coating process, no portion of the photoresist partially dries before the final spin stage. The final thickness of the photoresist is determined by concentration and the viscosity of the photoresist and the rpm of the final spin stage.
Illustrated in FIG. 5 are spin curves for suitable photoresists as are commercially available (a) Shipley 1075 photoresist, Shipley Co. Inc. of Marlborough, Mass., as well as for (b) SU8, available from Lighography Chemical Corp. of Watertown, Mass. The curves illustrate the film thickness achieved as a function of spinner rpm. For spin-coating, the film thicknesses t achieved generally follow a curve given by t = KC β V γ ω α , ( 9 )
where ω is the spin speed, C is the material concentration in the solvent, V is the viscosity, and α, β, and γ are constants. Consequently, given a particular photosensitive material solution of a certain concentration and viscosity, one can calculate the film thickness as a function of spin speed (rpm).
After the photoresist is spin-coated, the substrate is baked (typically called a soft bake or a prebake) in order to remove residual solvents and to anneal any stress in the photoresist film. This step controls the sensitivity of the photoresist. A longer and hotter softbake will tend to reduce the sensitivity of the film, but a too short or a too cool of a baking temperature will leave residual solvents in the resist film, that will affect the profiles of the final microstructures. Typically softbake temperatures are in the 90° to 110° C. range and the bake times are a few minutes for a hot plate, to 30 minutes to several hours for a convection oven. To ensure that the photoresist layer does not develop a slight wedge during the baking process, one should make the horizontal surfaces of the convection oven or hot plate level. When processing thick photoresist (>15 μm), if prior to the softbake step, the photoresist-coated substrates are preferably allowed to set out for what is termed a relaxation stage. This waiting period is typically on the order of 30 minutes, and helps reduce stresses in the thick photoresist film. For thick photoresist, hot plate soft bakes are preferential since the photoresist heating is occurring from the bottom of the film to the top. In this manner solvents are not trapped by the skinning of the photoresist top that can occur with oven bakes. For thick photoresist, one also wants to use a hot plate with a ramping feature so that the resist is slowly ramped up to its soft baking temperature, thereby reducing the chance of solvent bubbles to form in the photoresist.
An example of a photoresist coating recipe suitable used is:
1. Clean substrate
2. Dispense Shipley 1075 photoresist onto a clean substrate using a large pipette.
3. Spread stage: 200 rpm for 30 seconds
4. Final stage: 500 rpm for 3 minutes
5. Relaxation stage: Let substrate sit for 30 minutes.
6. Softbake: Hot plate at 90° C. for 10 minutes.
From FIG. 5, one notes that the above recipe will result in a photoresist film thickness that is 50 μm in thickness.
FIG. 6 illustrates other techniques for depositing photoresist, which may be preferable for coating non-plano substrates. These coating methods include meniscus coating, dip coating, vacuum coating, electroplating, and spray coating. In meniscus coating, see FIG. 6 ( a ), the substrate 61 is mounted horizontally below a roller 62 . Photoresist 63 is deposited on the roller, creating a meniscus above the substrate. By translating the roller, and hence the meniscus above the substrate, one can coat the substrate with a layer of photoresist 64 which is uniform to typically 5-10%.
In dip coating, see FIG. 6 ( b ), the substrate 65 is held in place by a clamp 66 . This clamp is mounted to a cantilever arm 67 which translates up and down along a rail 68 . In this manner, the substrate assembly can be dipped into a container 69 that holds photoresist 610 . Controlled pulling of the substrate out of the solution is required in order to achieve a uniform, non-striated, film coating. Once pulled out of the solution, the film is baked. In order to achieve thick films, higher viscosity material can be used, but more typically the substrate, once dipped, and coating is at least partially dried, is then dipped again. This process is repeated until the desired film thickness is achieved. Manufacturers of dip coaters include Chemat Technology, Inc. of Nothridge, Calif. The dip method may be used for coating plano and non-plano surfaces with photoresist films greater than 15 μm in thickness.
FIG. 6 ( c ) illustrates vacuum depositing of a photosensitive film. In vacuum deposition, the substrate 612 is placed into a vacuum chamber 611 that contains a source 613 of the material to coat. The source can be heated electrically or an ion or electron gun can be used to sputter the material 614 onto the substrate.
FIG. 6 ( d ) illustrates an electroplating technique which involves taking a conductive substrate 615 , and mounting it to an electrode 616 . The electrode is placed in a container 616 that holds an electroplating solution. The substrate is mounted such that it is below the fluid level 618 of the solution. A potential difference is created between the two electrodes using a power supply 619 . Due to this potential difference between the bath and substrate, the photoresist solution 620 plates onto the substrate. Resist thickness achieved depends upon numerous plating parameters such as applied voltage, bath temperature, and electroplating time. Photoresist conducive to electroplating is sold by Shipley as PEPR 2400 positive tone and Eagle 2100 ED negative tone. The electroplating process is particularly useful for coating non-plano substrates. The electroplating method may be used to coat photoresist with thickness over 15 μm.
Photoresist can also be coated using a spray method as shown in FIG. 6 ( e ). Machines for spray-coating photoresist can be obtained from such vendors as Specialty Coating Systems (SCS) of Indianapolis, Ind. A substrate 621 is placed on a mechanical stage, conveyor belt, or roller 622 . Above the substrate is a spray nozzle 623 that is mounted to an arm 625 that travels laterally along a rail 626 . The photoresist 624 is sprayed onto the substrate as the spray nozzle translates in a motion perpendicular to the substrate translation axis. Additional axes of motion may be added to the spray arm 625 in order to allow for the coating of non-flat substrates. The spray thicknesses depend upon multiple parameters such as spray velocity, nozzle shape, distance of spray nozzle to substrate, and velocity of the mechanics. In order to create films of thickness greater than 15 μm, one cannot necessarily use photoresist of a higher viscosity due to the tendency for the spray nozzle to become clogged. Rather, one can spray multiple coatings with a suitable bake step in between, or one can reduce the velocities of the mechanics in order to coat thicker layers in one step. The spray-coating method may be used for achieving resist films greater than 15 μm, however this method is not preferred because the uniformity may not be as good for plano substrates as in the spin-coating method. Spray coating, however, does have advantages for non-plano substrates.
Once coated, the photoresist is ready to be exposed to a varying dose of energy. As mentioned earlier, this can be achieved using a laser pattern generator, grayscale photolithography, translating apertures during exposure or holographically.
FIG. 7 illustrates schematically a laser pattern generator. This device will pattern a photosensitive substrate 71 mounted on mechanical stages 72 with a given exposure dosage as a function of the surface's spatial coordinates. Typically the exposure source 73 for such an instrument is a laser. For photoresist that is sensitive in the blue or UV portions of the electromagnetic spectrum, the radiation source used is typically an argon-ion, krypton-ion, or helium-cadium laser. With advances in semiconductor laser diodes, these gas lasers will most likely be replaced in the design of LPGs. The exposure source is intensity stabilized using a noise-eater 74 and is then modulated using an acoustopic modulator or an electro-optic modulator 75 . Note that although a single beam is being illustrated passing through their own intensity modulator. The multi-beam geometry is advantageous for increasing the writing speed of the LPG. Once modulated, the exposure beam or beams can be passed directly into a focusing objective 76 , or they can first pass through a beam deflector 77 , such as a set of mechanical galvos or AO deflector. The beam deflector 77 , along with the intensity modulator 75 are computer-controlled 711 and timed with the stage controller 78 to ensure that the appropriate exposure dosage mapping on the photosensitive substrate is achieved. The focusing of the exposure source onto the substrate is monitored through the use of an autofocus source 79 and detector 710 . In the case of photoresist that is not sensitive to radiation above 500 nm in wavelength, one can use a red or near-IR semiconductor laser as the autofocus radiation source. This autofocus system allows one to ensure that the exposure spot is accurately focused onto the substrate surface. This is particularly critical for high-NA system, wherein the depth of focus is sub-micron.
FIG. 8 illustrates two different geometries for grayscale mask lithography: (a) contact or proximity lithography and (b) projection lithography. In either geometry, an exposure source 81 is collimated using a condenser optical system 82 that can consist of any combination of lenses and reflective mirrors. The illumination radiation 83 is then incident upon a reticle or a photomask 84 that has a transmission that varies as a function of location across the mask clear aperture. The radiation transmitted (or reflected) by the grayscale reticle is thereby intensity modulated. In the case of contact or proximity printing, see FIG. 8 ( a ), the transmitted radiation propagates in free space and exposes a substrate 85 coated with a photoresensitive material 86 . The photomask can either be put directly in contact with the substrate (contact-printing), or a small gap (typically on the order of a micron) is made between the mask and the coated substrate in order to reduce the probability of contamination (proximity printing). In the case of projection lithography an imaging optical system 87 that consists of one or more refractive or reflective optical elements is used to protect the transmitted (or reflected) image of the grayscale reticle 84 onto a photosensitive substrate 85 , 86 .
FIG. 9 illustrates exposing a photosensitive material 95 with a rotating mask 94 . First an exposure source 91 is collimated by a lens or lens system 92 . The collimated radiation 93 is incident upon a mask 94 . In FIG. 9 we have illustrated a mask that consists of only opaque or clear areas in the form of a spiral. In general, one can have a grayscale mask. By rotating the mask such that the rotation time is short compared to the total exposure time. One can use a binary mask (either opaque or clear) to create a grayscale exposure of a photosensitive material. Note also that, one can construct a mask which is not merely rotated, but could also be translated for the exposure required to create a cylindrical lens.
FIG. 10 illustrates several different methods for developing photoresist that include (a) puddle developing, (b) spray developing, and (c) dip or immersion developing. In puddle developing the resist-coated 102 substrate 103 is mounted onto a vacuum or mechanical chuck 104 that is on a rotary spindle. 105 . Using a pipette 106 or any other means, the developer solution 101 is deposited onto the substrate surface and let sit for 30 seconds up to several minutes. After this period of time, the residual developer is spun off, and typically dionized (DI) water is sprayed onto the substrate to rinse the substrate during the spin step. Once rinsed, the DI water spray is shut off, and the substrate is allowed to spin dry. FIG. 10 ( b ) illustrates spray developing. Again, a resist-coated 1010 substrate 1011 is mounted to a vacuum or mechanical chuck 1012 that is mounted to a rotary spindle 1013 . While the substrate is spinning, developer 108 is sprayed onto the substrate use a spray nozzle 107 for a set period of time. Since the substrate is spinning, the solution developing the photoresist 109 is constantly being sheeted off of the substrate, and fresh developer is being sprayed on. After the developing stage, the rinse and dry stage is performed as for the puddle developing process. FIG. 10 ( c ) illustrates the dip or immersion method of developing resist-coated substrates. A resist-coated substrate 1015 , after being exposed, is secured to a holder 1014 by mechanical or vacuum means. This holder is immersed into a container 1016 the contains the photoresist developer such that the substrate is below the fluid line 1017 . During the development process, the substrate is typically gently agitated in the developer solution. After the development time has expired, the substrate, still secured by the holder, is lifted out of the developer solution and into a container 1018 that has DI water for the rinse stage. Again, the substrate is dipped below the water level line 1019 and gently agitated for tens of seconds to rinse the resist surface. After the rinse stage, the substrate can be spun dry, or dried through the use of compressed air or nitrogen guns.
In order to create the microstructure desired using any of the coating, exposing, and developing methods described, one needs to determine what the manufacturing parameters required in order to achieve a desired developed depth in a particular photosensitive material. This response or contrast curve of the photosensitive material is a function of the exposure power, wavelength, incident polarization, and collimation, but it is also highly dependent upon the photosensitive material used, the substrate the material is coated onto, as well as the specific coating and development procedures. The index of reaction, both real and imaginary portions, in addition to the incident polarization and collimation of the radiation beam determine how much energy is transmitted into the photoresist film, and how much is absorbed. If the photoresist is coated onto a reflective substrate, then the film will be exposed to a higher energy dose due to increased back reflections. Changing coating parameters (e.g., softbake times and temperatures) or changing development parameters (e.g., developer solutions, times, and temperatures) will change the sensitivity of the photoresist, and therefore the developed depth.
Once one has chosen a particular photosensitive material, a method for coating a surface with said material, a specific substrate material, exposure geometry, and a development method, one must conduct experiments to determine the response curves required in order to achieve specific continuous-relief surface profiles. FIG. 11 ( a ) illustrates a response curve obtained for the exposure of Shipley 1075 photoresist to a LPG. The exposure parameters were such that λ=0.4416 μm radiation was used with a N.A.=0.6 objective. The resist was spin-coated at 560 rpm and softbaked at 90° C. for 10 minutes on a hotplate. The development procedure used was an immersion technique wherein the exposed substrate was developed in a solution of DI:Shipley 303A (8:1) for 2.5 minutes. The curve in FIG. 11 ( a ) illustrates how exposure energies from 40 to 300 mJ/cm 2 result in photoresist depths that vary from 1 μm to 22 μm in depth. FIG. 11 ( b ) illustrates how development depth varies as a function of development time. In this scenario substrates with about 27 μm of Shipley 1075 photoresist were exposed to RPC's laser pattern generator (same parameters as for FIG. 11 ( a )). The curves illustrate the development time (in a DI:Shipley 303A 8:1 solution) and energy in mJ/cm 2 required reach a specific depth in resist. Similar curves can be generated for other forms of exposure geometries, such as the grayscale lithography and translating mask exposure, as illustrated in FIG. 8 and 9, respectively. Data from curves such as those illustrated in FIG. 11 can be used to determine the proper exposure dose and development procedure to use, given a specific photosensitive material and coating procedure, to fabricate arbitrary microstructures.
FIG. 12 illustrates white-light surface profilometry data for a f/1 hyperbolic lens that was fabricated using its laser pattern generator. The sag of the surface in microns is illustrated versus the radial coordinate of the lens in microns. One can use profilometry data to determine how well the fabricated profile matches that of the desired profile. Deviations can be fixed most easily by changing the look-up table or exposure dose as a function of position on the substrate surface. In the example illustrated, one notes that the deviation between the fabricated and ideal surface is less than 0.5 μm, and that the total sag of the photoresist microlens is roughly 24 μm.
FIG. 13 illustrates optical profilometry data for a f/2 spherical microlens. In FIG. 13 ( a ) the top-down contour map of the microlens is illustrated, while FIG. 13 ( b ) illustrates a 3-D view of the surface. In FIG. 13 ( c ) a line trace of the diagonal of the surface is depicted, illustrating a total surface sag of 23.2 μm. This microlens was patterned with a x-y LPG using Shipley 1075 photoresist.
FIG. 14 illustrates optical profilometry data for a toroidal microlens that is f/1.5 is one direction and f/3 in the orthogonal direction. This microlens was patterned with a x-y LPG using Shipley 1075 photoresist. In FIG. 14 ( a ) the top-down contour map of the microlens is illustrated. Note that for a toroidal microlens, the surface contour is oblong, illustrating the difference in optical power for the two orthogonal surface coordinates. In FIG. 14 ( b ) a 3-D view of the surface is illustrated. In FIG. 14 ( c ), a line trace of the diagonal of the surface is depicted, illustrating a total surface sag of 25.2 μm.
FIG. 15 illustrates possible alignment and registration marks that the method of the current invention allows one to simultaneously write in conjunction with the desired optical structures. These alignment marks are helpful for the wafer processing illustrated in FIG. 3 ( b ) and 3 ( c ), as well as in the alignment of the individual optical elements to the sources, fibers, or detectors they need to be integrated with. In FIG. 15 ( a ) and 15 ( b ) we illustrate an inverse cross and a cross that can be used to align two substrates with respect to each other using an optical microscope. In FIG. 15 ( c ) we illustrate a diffractive microlens that can be used as part of a micro-interferometer in order to align optical elements using optical alignment schemes.
The foregoing is only an illustrative example, the invention extends to the exposure of a photosensitive material to varying doses of electromagnetic radiation, for the purposes of creating a multi-level or continuous-relief profile that exceed 15 μm. The exposure process can be conducted using laser pattern generation, grayscale lithography, etc.
From the foregoing description, it will be apparent that there has been provided an improved system for the fabrication of micro-optics (optical microstructures) of arbitrary relief patterns. Variations and modification in the herein described systems in accordance with this invention will undoubtedly suggest themselves to those skilled in the art. Accordingly, the foregoing description should be taken as illustrative, and not in a limiting sense. | Fabrication of arbitrary profile micro-optical structures (lenses, gratings, etc.) and, if desired, with optomechanical alignment marks simultaneously during fabrication is based upon the use of low-contrast photosensitive material that, when exposed to a spatially variable energy dosage of electromagnetic radiation, can be processed to achieve multi-level or continuous surface-relief microstructures. By varying the exposure dose spatially based upon predetermined contrast curves of the photosensitive material, arbitrary one-dimensional (1-D) or two-dimensional (2-D) surface contours, including spherical, aspherical, toroidal, hyperbolic, parabolic, and ellipsoidal, can be achieved with surface sags greater than 15 μm. Surface profiles with advanced phase correction terms (e.g., Zernike polynomials) can be added to increase the alignment tolerance and overall system performance of the fabricated structure can also be fabricated. The continuous-relief pattern can be used as is in the photosensitive material, transferred into the underlying substrate through an etch process, electroformed into a metal, or replicated into a polymer. | 8 |
FIELD OF THE INVENTION
This invention may relate to fixtures for building fences or setting floor joists and the like. This invention also relates to the method of building a fence wherein the apparatus attaching the rails to the post is hidden from view.
BACKGROUND
Households have long used fences to demarcate property lines, to exclude others and to maintain privacy. Fences can add value to a residential home based on appearance and function. It is known in the art to put posts into the ground as the main structural support for a fence. It is also known to put a rail from post to post to further support the fence. Pickets can be hung from this structure or it can be covered in wire mesh.
In the case of privacy fences, cedar planks are attached to rails and are spaced closely to limit the view through the fence. These fences have the planks overlap the posts or butt up right next to the post. For years the only solution was to have a joist hanger that would wrap under the rail and attach to the post. This is unsightly and limits how close the planks or pickets can be to the post. It is therefore desirable to hide the means for attaching the rail to the post. It is also desirable to have the attachment means be below the attachment surface of the rail.
SUMMARY
The deficiencies in the art have been satisfied after a long felt need. An embodiment of the current invention is a bracket that can be used to attach rails to posts without being seen or without extending beyond the attachment side of the rail. This solution was not obvious because it may require a cut in the rail along its length to fit the bracket within the rail. The bracket may be attached to the posts at the appropriate height and then the rail with a slit cut along its length is slid down over the brackets protruding flange. The bracket has a plurality of slots at known distances on the protruding flange through which fasteners penetrate and attach the rail to the bracket. Another exemplary feature of the invention is alignment notches along the attachment flange which allow a builder to know where the plurality of slots are because the notches line up with the slots and can be seen with the rail in place. Additionally, a secondary or tertiary flange may extend perpendicular to the attachment flange or protruding flange to allow a rail to sit in place while it is fastened. Alternatively a distal bulge slightly larger than the slit in the rail will cause friction to hold the rail in place while it is fastened. This bracket allows all flanges of the bracket to be hidden in the rail or between the rail and the post. All fasteners can be sunk flush to the surface so all panels, planks or pickets sit flush and can be placed where ever the builder desires.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of one embodiment of the bracket.
FIG. 2 is a side view of the bracket of FIG. 1 .
FIG. 3 is a top view of another embodiment of the bracket.
FIG. 4 is a side view of the bracket of FIG. 3
FIG. 5 is a front view of the bracket of FIG. 3 and similar to the embodiment in FIG. 1 .
FIG. 6 is a perspective view of the bracket of FIG. 3 and is similar to the bracket in FIG. 1 .
FIG. 7 is a perspective view of one embodiment of the invention wherein a bracket is used in a fence.
FIG. 8 is a top view of the fence in FIG. 7 .
FIG. 9 is a perspective view of an embodiment of the invention wherein the bracket is used to hang floor joists.
FIG. 10 is a front view of an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The rail hanger 1 comprises a first flange 2 that protrudes away from two attachment flanges 4 . The distal end 3 of the first flange may be narrow or may have a distal bulge 9 to temporarily secure a rail 12 in place while permanent rail fasteners 17 are inserted. One of the major advantages of the rail hanger 1 may be that it is easily manufactured by making bends at the distal end 3 and at the attachment flange bends 10 . Another embodiment may have a lower bend 26 where the first flange 2 is manufactured from a single sheet of material and the attachment flanges 4 are folded away from the first flange.
Referring to FIG. 1 ; the rail hanger 1 has a first flange 2 that protrudes away from the attachment flange 4 . The first flange 2 consists of two pieces of material folded back adjacent to each other.
Referring to FIG. 2 ; the rail hanger 1 may have rail apertures 5 which may be in the form of slots or holes. The rail aperture is placed at a known distance to allow blind installation of rail fasteners 17 . Slots would allow variation in rail fastener 17 placement in the lengthwise direction of a rail 12 . The slots would still bear load in the vertical direction which is the primary loading of a rail 12 .
Referring to FIG. 3 ; the rail hanger 1 has an attachment flange 4 that may have a secondary flange 7 protruding perpendicular outward. The first flange 2 may have a tertiary flange 8 protruding perpendicular outward from the first flange 2 . The secondary flange 7 and tertiary flange 8 may either or both be on a rail hanger 1 to support a rail 12 while the rail fasteners 17 are installed.
FIG. 4 shows the rail apertures 5 through the first flange 2 .
Referring to FIG. 5 ; the rail hanger 1 comprises post attachment apertures 6 wherein fasteners attach the rail hanger 1 to a post 14 .
Referring to FIG. 6 ; the isometric view of a rail hanger shows the relationship of the alignment notches 27 and the rail apertures 5 . The alignment notches 27 can be seen while the rail 12 is in place. A builder can align a rail fastener 17 with the alignment notch 27 and be confident that the rail fastener 17 will clear the rail aperture 5 and continue into the rail 12 . This allows builders to quickly fasten the rail 12 to the rail hanger 1 without taking measurements and avoiding costly rework.
Referring to FIG. 7 ; a fence is constructed using a post 14 attached to a rail 12 using a rail hanger 1 . The gap between the rail 12 and post 14 is exaggerated to show the rail hanger 1 . Rail fasteners 17 are installed through the rail 12 and through the rail apertures 5 . Pickets 13 or planks are attached to the rail 12 and may be attached adjacent to the post 14 without interference with the rail hanger 1 . The rail hanger 1 is hidden on the back side of the fence and can only be seen through a small gap.
Referring to FIG. 8 ; a rail 12 has a rail slit 19 extending along the length of the rail 12 through which the rail hanger 1 extends.
Referring to FIG. 9 ; a rail hanger 1 extends into a floor joist 15 through a joist slit 20 cut into the floor joist 15 . Joist fasteners 18 extend through the joist 15 and the rail hanger 1 . The rail hanger is fastened to the band 16 and load from the joists 15 is transferred into the band 16 . The rail hanger 1 may made from a material that is folded to shape. A preferred embodiment may be a galvanized or stainless steel approximately one sixteenth of an inch ( 1/16″) thick. This allows the rail hanger 1 to fit into a rail slit 19 or joist slit 20 that is one eighth of an inch (⅛″) or the standard blade width of a circular saw cut. The material for the rail hanger 1 may be galvanized steel, stainless steel, aluminum, copper, plastic or wood. The material thicknesses may be preferably 0.005″ to 0.1.″ The slit width 19 , 20 may be preferably 0.010″ up to 0.200″ and from 1 inch up to 4 inches deep from end of rail 25 . The distance from top of first flange 21 to bottom of first flange 22 is approximately the width of the board used as the rail 12 . For rough 2×4″ boards this distance would be just less than 4 inches. For rough 2×8″ joists this distance would be approximately under 8 inches. Finished board are one half inch smaller in each dimension. This distance could feasibly range from one inch to sixteen inches.
The method of making a fence comprises putting posts 14 in post holes. Rails 12 are cut to length to fit between posts 14 . Slits 19 are cut through the center of the rails 12 from rail top 23 to rail bottom 24 to a depth of up to 2 inches from end of rail 25 . A rail hanger 1 is fastened to the posts 14 using fasteners through post attachment apertures 6 at a desired height. The rails 12 are put in place with the rail hanger first flange 2 within the slit 19 in the rail 12 . Rail fasteners 17 are fastened through the rail 12 and rail hanger 1 . The rail fasteners are aligned using the alignment notches 27 which are visible after a rail 12 is put in place. Pickets or planks 13 are fastened to the rail 12 . | The invention may relate to a bracket that is used in building fences or floor joists or the like. The bracket is substantially concealed from view after assembly. The invention may also be a method for building fences involving a bracket that is concealed from view after the fence is completed. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a nonprovisional patent application of U.S. Provisional Patent Application Ser. No. 61/691,140, filed 20 Aug. 2012; U.S. Provisional Patent Application Ser. No. 61/765,484, filed 15 Feb. 2013; and U.S. Provisional Patent Application Ser. No. 61/818,882, filed 2 May 2013, each of which is hereby incorporated herein by reference.
Priority of U.S. Provisional Patent Application Ser. No. 61/691,140, filed 20 Aug. 2012; U.S. Provisional Patent Application Ser. No. 61/765,484, filed 15 Feb. 2013; and U.S. Provisional Patent Application Ser. No. 61/818,882, filed 2 May 2013, each of which is hereby incorporated herein by reference, is hereby claimed.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
REFERENCE TO A “MICROFICHE APPENDIX”
Not applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to continuous batch washers or tunnel washers. More particularly, the present invention relates to an improved method of washing textiles or fabric articles (e.g., clothing, linen) in a continuous batch multiple module tunnel washer wherein the textiles are moved sequentially from one module to the next module and wherein one or more modules have conductivity sensors that monitor water conductivity. Water is selectively transferred in order to maintain water conductivity to within a pre-selected acceptable range which aids in proper ironing of textile articles.
2. General Background of the Invention
Currently, washing in a commercial environment is conducted with a continuous batch tunnel washer. Such continuous batch tunnel washers are known (e.g., U.S. Pat. No. 5,454,237) and are commercially available (www.milnor.com). Continuous batch washers have multiple sectors, zones, stages, or modules including for example, pre-wash, wash, rinse and finishing zone.
Commercial continuous batch washing machines in some cases utilize a constant counterflow of liquor. Such machines are followed by a centrifugal extractor or mechanical press for removing most of the liquor from the goods before the goods are dried. Some machines carry the liquor with the goods throughout the particular zone or zones.
When a counterflow is used in the prior art, there is counterflow during the entire time that the fabric articles or textiles are in the main wash module zone. This practice dilutes the washing chemical and reduces its effectiveness.
A final rinse with a continuous batch washer has been performed using a centrifugal extractor or mechanical press. A problem occurs in prior art systems when the water that is used for the press has a conductivity that exceeds a preset limit (for example, about 1,000 microsiemens) above incoming fresh water. In such a case, the press water with excessive conductivity can cause the linen to stick to ironing implements such as an ironer roll that rests upon a chest. Without proper rinsing with water having proper conductivity, the linen can stick on the chest part of the ironer roll.
Patents have issued that are directed to batch washers or tunnel washers. The following table provides examples of such patented tunnel washers, each listed patent of the table being hereby incorporated herein by reference.
TABLE
PAT.
ISSUE DATE
NO.
TITLE
MM-DD-YYYY
4,236,393
Continuous tunnel batch washer
12-02-1980
4,485,509
Continuous batch type washing machine
12-04-1984
and method for operating same
4,522,046
Continuous batch laundry system
06-11-1985
5,211,039
Continuous batch type washing machine
05-18-1993
5,454,237
Continuous batch type washing machine
10-03-1995
BRIEF SUMMARY OF THE INVENTION
The present invention provides an improved method of washing fabric articles in a continuous batch tunnel washer. The method includes providing a continuous batch tunnel washer having an interior, an intake, a discharge, a plurality of modules, and a volume of liquid.
The present invention provides an improved method and apparatus for washing or laundering items in a continuous batch or tunnel washer. The present invention provides an improved method and apparatus for laundering articles in a continuous batch or tunnel washer that also employs an extractor such as a centrifuge or press, solving a problem that results in a sticking or adherence of the linen to the chest of an ironer roll because of improper conductivity of the water.
The present invention provides a tunnel washer or continuous batch washer that employs conductivity sensors located in one or more positions such as for example the press tank, incoming fresh water stream, and “pulse flow” tank.
In one embodiment, the maximum conductivity range of the press water is compared to incoming fresh water.
In one embodiment, the maximum conductivity range of the pulse flow tank water is compared to incoming fresh water.
In one embodiment, if the press water conductivity exceeds a preset limit (for example, 1,000 microsiemens above incoming fresh water), the fresh water then flows from one of the modules (for example, the last module) into the press tank such as for example during a “pulse flow” or higher velocity flow time of a transfer cycle.
In this manner, the conductivity of the press water will be adjusted (e.g., lowered) back to a pre-programmed, pre-selected acceptable range. The present invention thus corrects a problem before the pulse flow tank can reach a conductivity that is beyond a desired or selected range.
With the present invention, if an upset condition occurs in the pulse flow tank (i.e., exceeding its programmed range), a drain valve can be used to discharge water flow directly into the tank to correct the upset condition.
An alternate method provides an “empty pocket” that is inserted into a module such as module 1 (e.g., first module) with the drain open. The “empty pocket” is simply a module that is purposefully not filled with fabric articles (e.g. linen, clothing, or the like). Water from a pump counter flows from one of the later modules (e.g. module 8 ) to sewer through the first module drain. Upon the next transfer of fabric articles to the next downstream module, the “empty pocket” advances to second module, then to the third module and so forth. For an eight module washer, the empty pocket will initially be the first module or module 1 . The empty pocket then moves to the second module or module 2 . The empty pocket then moves in sequence to module three, then module 4 , then module 5 then module 6 then module 7 and finally module 8 is the empty pocket. In each module that is the empty pocket, the water from the pump is diverted to sewer. This method recovers the over conductivity measured in the press water faster because the free water that has too high a conductivity in the pulse flow zone is cleared faster by diverting the pulse flow water into the advancing “empty pocket” that has no clothing, linen, or fabric articles. This alternate method minimizes the time out of range conductivity by about 40 to 50% (one method requires 6 to 10 transfers to clear the conductivity error whereas the alternate method only requires 2 to 6 transfers).
The present invention includes a method of washing fabric articles in a continuous batch tunnel washer. The method can provide a continuous batch tunnel washer having an interior, an intake, a discharge, a plurality of modules, and a volume of liquid. The fabric articles can be moved from the intake to the modules and then to the discharge in sequence. A washing chemical can be added to the volume of liquid. The fabric articles can be discharged after to an extractor that removes excess water from the fabric articles, discharging said excess water to a press water tank. An ironer can be provided that receives fabric articles. Conductivity can be monitored of fluid in at least one of the modules. Conductivity can be monitored of fluid in the press water tank. Water can be added to one or more modules if the conductivity of water in the press water tank exceeds a threshold value so that the fabric articles to be ironed hold only water with a conductivity that is within an acceptable conductivity range.
In one embodiment, the extractor can be a press.
In one embodiment, the extractor can be a centrifuge.
In one embodiment, the threshold value can be about 1000 microSiemens per centimeter.
In one embodiment, the threshold value can be between about 100 micro Siemens and 1000 micro Siemens above the conductivity value of the incoming or available water or source water.
In one embodiment, the invention further includes the step of after a selected time period, counter flowing a rinsing liquid along a flow path that can be generally opposite the direction of travel of the fabric articles.
In one embodiment, the water added can be a fresh influent water stream.
The present invention includes a method of washing and drying fabric articles in a continuous batch tunnel washer and ironer. The method can provide a continuous batch tunnel washer having an interior, an intake, a discharge, and a plurality of modules that segment the interior. The fabric articles can be moved from the intake to the discharge. A washing chemical can be added to one or more of the modules. The fabric articles can be discharged. A source of fresh, make-up water can be provided. Conductivity can be monitored of fluid in at least one of the modules. Conductivity can be monitored of fluid in the discharged fabric articles. Make-up water can be added to one or more modules if the conductivity of water in the discharged fabric articles exceeds a threshold value.
In one embodiment, the present invention further includes the step of extracting water from the fabric articles, the extracted water can be monitored for said conductivity to provide the value of conductivity for the discharged fabric articles.
In one embodiment, the threshold value is at least about 100 micro Siemens above the conductivity value of the incoming or available water or source water.
In one embodiment, the present invention further includes maintaining the conductivity of the water in the discharged fabric articles to a value of between about between about 100 micro Siemens and about 1000 micro Siemens above the conductivity value of the incoming or available water or source water.
The present invention includes a method of washing fabric articles in a continuous batch tunnel washer. The method provides a continuous batch tunnel washer having an interior, an intake, a discharge, and a plurality of modules that segment the interior and wherein one of the modules is an empty pocket that is drained of water. Fabric articles can be moved from the intake to the discharge and through the modules in sequence. A washing chemical can be added to one or more of the modules. The fabric articles can be rinsed by counter flowing liquid in the washer interior along a flow path that is generally opposite the direction of travel of the fabric articles, wherein one of the modules defines and empty pocket that is drained of water during this step, wherein one of the modules can be an empty pocket that is drained of fluid during such rinsing with counterflowing liquid. Wherein one of the modules can be an empty pocket that is drained of fluid.
In one embodiment, one of the modules can be an empty pocket that is drained of fluid and that does not have any fabric articles such as linens.
In one embodiment, the invention further comprises extracting excess fluid from the fabric articles.
In one embodiment, the empty pocket is moved from an upstream location to a downstream location. For example, for an eight module washer, the empty pocket moves from the first module at the intake end of the washer and then to modules 2 , 3 , 4 , 5 , 6 , 7 , 8 in sequence.
In one embodiment, the empty pocket separates white fabric articles from non-white fabric articles.
In one embodiment, the empty pocket separates white fabric articles from colored fabric articles.
In one embodiment, the empty pocket separates higher temperature modules from lower temperature modules.
The present invention includes a method of laundering fabric articles in a continuous batch tunnel washer. The method can provide a continuous batch tunnel washer having an interior, an intake, a discharge, and a plurality of modules that segment the interior. Fabric articles can be moved in a first direction of travel from the intake to the discharge. The fabric articles can be washed with a chemical bath in one or more of said modules. The fabric articles can then be rinsed. An empty pocket can be provided in one or more of said modules that is drained of fluid. Wherein the empty pocket is moved in a direction from the intake towards the discharge. Liquid can be counterflowed in the washer during the step of rinsing the fabric.
Another embodiment of the present invention includes a method of washing fabric articles in a continuous batch tunnel washer, comprising the steps of: a) providing a continuous batch tunnel washer having an interior, an intake, a discharge, and a plurality of modules that segment the interior and wherein one of the modules is an empty pocket that is drained of water, said modules including a first module next to the intake and a final module next to the discharge; b) moving the fabric articles from the intake to the discharge and through the modules in a sequence beginning with the first module and ending with the final module; c) adding a washing chemical to one or more of the modules; d) rinsing the fabric articles by counter flowing liquid in the washer interior along a flow path that is generally opposite the direction of travel of the fabric articles in steps “b” and “c”; e) wherein one of the modules defines an empty pocket module that is drained of fluid during step “d”; and f) wherein the modules that are not empty pocket modules contain both fabric articles and fluid.
In another embodiment, the method of the present invention further comprises extracting excess fluid from the fabric articles after step “e”. In one embodiment, the empty pocket is moved from an upstream location to a downstream location.
In another embodiment of the method of the present invention, the empty pocket separates white fabric articles from non-white fabric articles, and in another embodiment, the empty pocket separates white fabric articles from colored fabric articles. In another embodiment, the empty pocket separates higher temperature modules from lower temperature modules.
In another embodiment of the method of the present invention, there are multiple different counterflow streams in step “d”. In one embodiment, one counterflow stream in step “d” rinses white fabric articles and another counterflow stream rinses the non-white fabric articles. In one embodiment, one counterflow stream in step “d” rinses white fabric articles and another counterflow stream rinses colored articles. In another embodiment one counterflow stream rinses higher temperature modules and another counterflow stream rinses lower temperature modules.
Another embodiment of the present invention includes a method of laundering fabric articles in a continuous batch tunnel washer, comprising the steps of: a) providing a continuous batch tunnel washer having an interior, an intake, a discharge, and a plurality of modules that segment the interior; b) moving the fabric articles and fluid in a first direction of travel from the intake to the discharge; c) washing the fabric articles with a chemical bath in one or more of said modules; d) rinsing the fabric articles after step “c”; e) providing an empty pocket in one or more of said modules that is drained of fluid; f) wherein the empty pocket is moved from one module to the next module in sequence, and in a direction from the intake towards the discharge; and g) counterflowing liquid in the washer during step “d”.
Another embodiment of the present invention includes a method of washing fabric articles in a continuous batch tunnel washer, comprising the steps of: a) providing a continuous batch tunnel washer having an interior, an intake, a discharge, and a plurality of modules that segment the interior and wherein one of the modules is an empty pocket that is drained of water; b) moving the fabric articles and a volume of liquid from the intake to the discharge and through the modules in sequence; c) adding a washing chemical to one or more of the modules; d) rinsing the fabric articles by counter flowing liquid in the washer interior along a flow path that is generally opposite the direction of travel of the fabric articles in steps “b” and “c”; and e) wherein one of the modules defines an empty pocket module that is drained of liquid during step “d”.
In another embodiment of the method of the present invention, the method further comprises extracting excess fluid from the fabric articles after step “e”.
In another embodiment of the method of the present invention, the empty pocket is moved from an initial upstream location to downstream modules that are downstream of said initial upstream location.
Another embodiment of the present invention includes a method of laundering fabric articles in a continuous batch tunnel washer, comprising the steps of: a) providing a continuous batch tunnel washer having an interior, an intake, a discharge, and a plurality of modules that segment the interior and including at least one intake module and at least one final module; b) moving the fabric articles in a first direction of travel from the intake to the discharge; c) washing the fabric articles with a chemical bath in one or more of said modules; d) rinsing the fabric articles after step “c”; e) providing an empty pocket in one or more of said modules that is drained of fluid; f) wherein the empty pocket is moved one module at a time starting at the intake module and ending at the final module, and in a direction from the intake towards the discharge; and g) counterflowing liquid in the washer during step “d”.
In another embodiment of the method of the present invention, the empty pocket separates white fabric articles from non-white fabric articles, and in another embodiment the empty pocket separates white fabric articles from colored fabric articles. In one embodiment the empty pocket separates higher temperature modules from lower temperature modules.
In another embodiment of the method of the present invention, there are multiple different counterflow streams in step “g”. In one embodiment one counterflow stream in step “d” rinses white fabric articles and another counterflow stream rinses non-white fabric articles. In another embodiment, one counterflow stream in step “d” rinses white fabric articles and another counterflow stream rinses colored fabric articles. In another embodiment of the method of the present invention one counterflow stream rinses higher temperature modules and another counterflow stream rinses lower temperature modules.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
FIG. 1 is comprised of half FIGS. 1A-1B that connect at match lines A-A, providing a schematic diagram showing a preferred embodiment of the apparatus of the present invention;
FIG. 2 is comprised of half FIGS. 2A-2B that connect at match lines B-B providing a schematic diagram showing a preferred embodiment of the apparatus of the present invention;
FIG. 3 is a fragmentary view of a preferred embodiment of the apparatus of the present invention illustrating the ironer rolls for demonstrating that without proper rinsing the linen can stick to the chest portion of the ironer roll;
FIG. 4 is comprised of half FIGS. 4A-4B that connect at match lines C-C, providing a diagram of an alternate embodiment of the apparatus of the present invention;
FIG. 5 is a fragmentary view of the alternate embodiment of the apparatus of the present invention;
FIG. 6 is a diagram of an alternate embodiment of the apparatus of the present invention showing a five module tunnel washer for use in the hospitality industry and with chlorine bleach;
FIG. 7 is a diagram of an alternate embodiment of the apparatus of the present invention showing a five module tunnel washer for use in the hospitality industry and with hydrogen peroxide;
FIG. 8 is a diagram of an alternate embodiment of the apparatus of the present invention showing a five module tunnel washer for use in the hospitality industry and with sanitizing sour;
FIG. 9 is a diagram of an alternate embodiment of the apparatus of the present invention showing a seven module tunnel washer for use in the hospitality industry and with chlorine bleach;
FIG. 10 is a diagram of an alternate embodiment of the apparatus of the present invention showing a seven module tunnel washer for use in the hospitality industry and with hydrogen peroxide;
FIG. 11 is a diagram of an alternate embodiment of the apparatus of the present invention showing a seven module tunnel washer for use in the hospitality industry and with sanitizing sour;
FIG. 12 is a diagram of an alternate embodiment of the apparatus of the present invention showing an eight module tunnel washer for use in the hospitality industry and with chlorine bleach;
FIG. 13 is a diagram of an alternate embodiment of the apparatus of the present invention showing an eight module tunnel washer for use in the hospitality industry and with hydrogen peroxide;
FIG. 14 is a diagram of an alternate embodiment of the apparatus of the present invention showing an eight module tunnel washer for use in the hospitality industry and with sanitizing sour;
FIG. 15 is a diagram of an alternate embodiment of the apparatus of the present invention showing a ten module tunnel washer for use in the hospitality industry and with chlorine bleach;
FIG. 16 is a diagram of an alternate embodiment of the apparatus of the present invention showing a ten module tunnel washer for use in the hospitality industry and with sanitizing sour;
FIG. 17 is a diagram of an alternate embodiment of the apparatus of the present invention showing a twelve module tunnel washer for use in the hospitality industry and with chlorine bleach;
FIG. 18 is a diagram of an alternate embodiment of the apparatus of the present invention showing a twelve module tunnel washer for use in the hospitality industry and with hydrogen peroxide;
FIG. 19 is a diagram of an alternate embodiment of the apparatus of the present invention showing a twelve module tunnel washer for use in the hospitality industry and with sanitizing sour;
FIG. 20 is a schematic diagram of a preferred embodiment of the apparatus of the present invention showing a twelve module tunnel washer with alternate pulse flow and long distance incompatibility avoidance for incompatible batches;
FIG. 21 is a schematic diagram of an alternate embodiment of the apparatus of the present invention having alternate pulse flow and long distance incompatibility avoidance wherein white textile articles follow colored or non-white textile articles;
FIG. 22 is a schematic diagram of a preferred embodiment of the apparatus of the present invention showing an eight module tunnel washer with alternate pulse flow and wherein low temperature white fabric articles follow high temperature white fabric articles;
FIG. 23 is a schematic diagram of a preferred embodiment of the apparatus of the present invention showing an eight module tunnel washer with alternate pulse flow and wherein low temperature white fabric articles follow high temperature white fabric articles; and
FIG. 24 is a schematic diagram of a preferred embodiment of the apparatus of the present invention showing an eight module tunnel washer with alternate pulse flow and wherein color fabric articles follow white fabric articles.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1-2 show a preferred embodiment of the apparatus of the present invention designated generally by 10 A in FIGS. 1 and 2 . It should be understood that FIG. 1 includes half FIGS. 1A and 1B that assemble at match lines A-A. FIG. 2 includes half FIGS. 2A and 2B that assemble at match lines B-B. In FIG. 1 there can be seen a textile washing apparatus 10 A which employs a tunnel washer 11 having an inlet end portion 12 and an outlet end portion 13 . The inlet end portion 12 has a hopper 14 that enables the tunnel washer 11 to accept soiled linen or fabric articles 25 as indicated generally by arrow 16 in FIG. 2 . A discharge 15 from tunnel washer 11 enables laundered articles such as linen to be transferred from tunnel washer 11 to an extractor the removes water such as a press 19 . From the press or extractor 19 , the laundered articles can be moved using a shuttle 20 to a dryer 21 and then via transport 22 to a finishing station 23 (see FIG. 2 ). The tunnel washer 11 provides a plurality of modules or stations 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 . Fabric articles to be cleaned are moved generally in the direction of arrows 17 , 18 in FIG. 2 . Counterflow flow lines 193 are provided for counterflowing fluid from one module (e.g. module 4 ) to the previous module (module 3 ). Such counterflow flow lines 193 can be provided for each embodiment of FIGS. 1-24 to counterflow fluid from any downstream module to an upstream module or in a direction opposite to arrows 17 , 18 . In FIG. 1 , there is provided an extractor reuse tank 24 and a “pulse flow” tank 26 . “Pulse flow” tank 26 provides a supply of water to pumps 38 , 69 . These pumps then transmit water at a high flow rate (e.g., between 75 (283) and 250 (946.4) gallons (liter) per minute) to a selected module or modules.
A plurality of conductivity sensors are provided as part of the apparatus 10 A. In FIG. 1 , a conductivity sensor 27 is provided in the extractor reuse tank 24 . Another conductivity sensor 28 is provided in the pulse flow tank 26 . A third conductivity sensor 29 is provided in the influent flow line 30 to monitor the conductivity of fresh water that is flowing through the influent flow line 30 (from a selected source). The source of fresh water in flow line 30 can include a cold source 79 of fresh water as well as a hot or tempered source 80 of fresh water. The present invention monitors conductivity of water that is contained in the modules 1 - 10 and adjusts by adding fresh water or make up water in order to maintain the conductivity in modules 1 - 10 within a selected or desired range (i.e. between about 100 micro Siemens (minimum value) and a maximum value of about 1000 micro Siemens above the conductivity value of the incoming or available water or source water).
Because the fluid that is discharged from modules 9 and 10 through valves 63 and 64 enters extractor reuse tank 24 , the conductivity sensor 27 in tank 24 monitors the conductivity of the tunnel washer modules 9 and 10 . Valve 63 feeds flow line 65 . A tee fitting 67 joins valve 64 with lines 65 and 66 as shown in FIG. 1 . The line 66 feeds water to the extractor reuse tank 24 where conductivity is measured by sensor 27 .
Pump 58 discharges water from extractor reuse tank 24 and transmits that water via line 68 to the pulse flow tank 26 . Valves can be provided at 60 , 34 in flow line 68 . A drain can be provided in the form of valve 61 as shown in FIG. 1 for discharging directly to a sewer 62 or other suitable drain. A valve 59 is provided for discharging water directly from extractor reuse tank 24 if desired.
Water in pulse flow tank 26 is monitored for conductivity using conductivity sensor 28 . The conductivity of water in tank 26 can be monitored and adjusted by introducing water from an outside source 79 and/or 80 through flow line 30 and meter 31 . Conductivity sensor 29 monitors the conductivity of water in flow line 30 before it reaches pulse flow tank 26 . Additionally, the water in tank 26 is also monitored for conductivity by sensor 28 . Flow meter 31 and valve 32 can be provided in flow line 30 . Water can be discharged from tank 26 to sewer 43 by opening valve 33 . Water can also be discharged from tank 26 through flow line 37 using pump 38 . Water exiting tank 26 through flow line 37 can be injected into either module 8 or 9 as shown in FIG. 1 using valves 39 , 41 or 42 .
A plurality of flow meters can be provided in the various flow lines. The flow line 37 can be equipped with a flow meter 40 . A flow meter 31 is provided in the influent flow line 30 . A flow meter 47 is provided in the flow line 44 .
The influent flow line 30 provides a valve 32 . The influent flow line 30 provides make up water as needed for the pulse flow tank 26 . The module 10 can be a standing bath. The module 9 can be a standing bath or wash module.
Flow line 35 and pump 69 in FIG. 1 enable water to be transferred from pulse flow tank 26 to module 10 . Flow line 35 can be provided with valve 36 . Flow line 44 transfers water from module 5 to module 4 . Flow line 44 can be provided with pump 45 , valve 46 and flow meter 47 . Flow line 48 enables water to be transferred from module 1 through pump 49 into hopper 14 . In this fashion, soiled laundry or other textile articles added to hopper 14 are immediately wetted with a fast moving stream of water while entering module 1 . This function allows the washing process to start in module 1 whereas previous practice module 1 was used only to wet the linen. Flow line 50 enables fresh water to be added directly to module 10 . Influent flow line 50 can be provided with flow meter 51 and tee fitting 52 . Tee fitting 52 enables fresh water to be transferred to either flow line 53 or 54 , each equipped with a valve 55 or 56 as shown. In this fashion, fresh water can be added to either module 9 or 10 in order to adjust conductivity of the water in those modules 9 and 10 to a selected range. A tee fitting 71 can be provided in flow line 35 for adding water directly to hopper 14 . The tee fitting 71 enables water to enter hopper 14 through flow line 72 which is equipped with valve 57 and flow meter 70 .
FIG. 3 shows an ironer that is designated generally by the numeral 73 . Ironer 73 can include multiple rolls or rollers 75 , each supported upon a chest 74 . In the prior art, linen sheets or other fabric articles 25 could stick to the chest 74 without proper rinsing. Further, if the conductivity of the water in the linen sheets or fabric articles 25 was outside a selected range, the linen could stick to any one of the chests 74 .
With the present invention, the linen sheets or fabric articles 25 (which are indicated schematically by the dotted line 77 ) in FIG. 3 are less likely to stick to the chest 74 because conductivity of the water is monitored and held within a selected range of between about 100 micro Siemens (minimum value) and a maximum value of about 1000 micro Siemens above the conductivity value of the incoming or available water or source water. In FIG. 3 , the arrow 76 schematically illustrates the intake of linen sheets whereas the arrow 78 indicates schematically the discharge of linen sheets after ironing. The ironer 73 shown in FIG. 3 can be part of the finishing station 23 of FIG. 2 .
FIGS. 4-5 show an alternate embodiment of the apparatus of the present invention designated as 10 B. It should be understood that FIG. 4 includes half FIGS. 4A-4B that assemble at match lines C-C. As with the embodiment of FIGS. 1-3 , textile washing apparatus 10 B provides a tunnel washer 11 having a plurality of modules or stations (e.g., between 1 and 32 stations or modules) 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , inlet end portion 12 , outlet end portion 13 and discharge 15 . The apparatus 10 B can employ the press/extractor 19 , shuttle 20 , dryer 21 , transport 22 and finishing station 23 of FIG. 2 and the ironer 73 arrangement of FIG. 3 .
Fabric or textile articles 25 to be cleaned are added to hopper 14 at inlet end portion 12 . Fabric or textile articles 25 to be cleaned are moved generally in the direction of arrows 17 , 18 in FIG. 4 . In FIGS. 4-5 , an “empty pocket” is provided in a selected module 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 or 10 . For example, the empty pocket can initially be module 1 , the first module that is next to the inlet end portion 12 . The empty pocket then moves in sequence to the second module 2 , then to the third module 3 , then to modules 4 , 5 , 6 , 7 , 8 , 9 and finally module 10 . This “empty pocket” module typically has no linen. Notice in FIG. 5 that the empty pocket with no linen is module 3 . The empty pocket module is created by allowing a transfer of linen from one module to the next for all modules other than the empty pocket module.
For the empty pocket module, no linen is put into the first empty pocket module 1 . On the next transfer of linen from each module to the next module, the empty pocket module is now module 2 . It is possible to have more than one empty pocket module by means of programming the controller. This “empty pocket” module arrangement minimizes the time out of range conductivity by about forty to fifty percent (40-50%). With the alternate method and apparatus of FIGS. 4-5 , as few as two to six transfers are needed to clear a conductivity error compared to between ten and twenty transfers required for a comparable tunnel washer that does not employ this “empty pocket” module arrangement of FIGS. 4-5 .
As with the preferred embodiment of FIGS. 1-3 , textile washing apparatus 10 B can employ conductivity sensors 27 , 28 , 29 . Many of the flow lines, valves, fittings and components of FIG. 1 can be seen in FIG. 4 . In FIG. 5 , water header 121 is supplied with water from tank 26 with an alternate pump 122 . Module 2 receives water through fill valve 124 during a “pulse flow” portion of the cycle. The overall cycle sequence is comprised of three functions: (1) standing bath, which can be about 75% of the cycle; (2) “pulse flow” (high speed or high flow rate rinsing), which can be about 24% of the cycle; and (3) transfer (movement of the linen from one module to the next module, e.g., module 1 to module 2 ), which can be about 1% of the cycle.
“Pulse flow” is a high velocity rinsing step. Flow line 121 is a simplified representation of the headers shown in FIG. 4A . Pump 101 (the alternative pulse flow pump) supplies water to header 102 or header 104 . In FIG. 5 , flow line 121 represents either of these headers 102 , 104 . The empty pocket separates heavily lint fabric articles (e.g., bar towels) from different fabric articles (e.g., table linen). Although valve 124 remains open during the pulse flow portion of the cycle, no water flows because the alternate pulse flow pump 122 is turned off. Fill valves 123 , 125 and 126 are closed. Water counterflows from module 4 to module 3 via a counterflow flow line 193 and through open valve 134 . However, this water goes immediately to sewer 128 via flow line 127 (see arrow 140 , FIG. 5 ) and open drain valve 130 . Module 3 (the empty pocket module) remains empty of water. The valve conditions shown in FIG. 5 accompany an empty pocket of module 3 . This valve condition moves with the “empty pocket” as it moves from one module to the next module through the tunnel washer 11 in the direction of arrows 17 , 18 . In the method and apparatus of FIGS. 4 and 5 , the “empty pocket” is first placed in module 1 , then moves to module 2 , then 3 , then to each subsequent module in sequence: 4 , 5 , 6 , 7 , 8 , 9 until the empty pocket reaches the last module 10 . In this case where module 10 is the empty pocket, the controller will signal the receiving apparatus, such as a press or an extractor, that there is no linen in the press or extractor so that it does not cycle.
Counterflow in washer 11 is controlled by the counterflow valves 132 , 133 , 134 , 135 . Counterflow is permitted when the valve 133 for flow from module 3 to the previous module 2 is open and the valve 136 for flow to the sewer 128 is closed. Counterflow is prevented when the valve states are opposite. Although counterflow would be possible between module 3 and module 2 in FIG. 5 , there is no water available for counterflow as long as drain valve 130 remains open. Any chemical inlets or dispensers 120 on module 3 remain closed during the empty pocket portion of the cycle.
In FIG. 4 , flow line 81 connects with Tee-fitting 82 to flow line 102 . Line 81 provides valve 83 and flow meter 84 . Line 102 provides valve 85 . As can be seen in FIG. 4 , line 102 discharges into module 9 . Tee-fittings are provided at 86 , 87 and flow line 102 . Line 88 connects with flow line 102 at Tee-fitting 86 . Line 88 provides valve 89 and discharges into module 7 . Line 90 joins line 102 at Tee-fitting 87 . Line 90 provides valve 91 and discharges into module 8 . Flow line 92 has flow meter 93 and valve 94 . Tee-fitting 95 joins flow line 92 with flow line 104 . Line 92 has valve 96 , Tee-fitting 97 and flow meter 99 . Line 103 joins line 92 at Tee-fitting 97 . Below Tee-fitting 97 , line 92 is designated as 100 and connects with pump 101 that communicates with tank 26 . Flow line 81 has valve 98 and is designated as line 103 below Tee-fitting 102 , joining with line 100 at fitting 97 . Flow line 104 joins to line 92 at Tee-fitting 95 . Tee-fittings 105 , 106 , 107 and 108 are provided in flow line 104 . Line 109 connects to Tee-fitting 105 . Line 110 connects to Tee-fitting 106 . Line 111 connects to line 104 at Tee-fitting 107 . Line 112 connects to line 102 at Tee-fitting 108 . Flow line 109 has valve 114 . Flow line 110 has valve 115 . Flow line 111 has valve 116 . Flow line 112 has valve 117 . Flow line 104 has valve 118 .
FIGS. 6-24 show variations of the washing apparatus 10 A, 10 B of FIGS. 1-5 . FIG. 6 shows a five module washing apparatus, designated generally by the numeral 10 C. Washing apparatus 10 C can be a tunnel washer having modules 1 , 2 , 3 , 4 , 5 wherein modules 1 , 2 , 3 , 4 can be dual use modules that perform both wash and rinse functions. Module 5 is a finish module. Washing apparatus 10 C has an inlet end portion with hopper 14 for intake of laundry or textile articles or linens and a discharge end portion that discharges fabric articles, linens, laundry to an extraction device 19 (e.g., press or centrifuge). As with the embodiments of FIGS. 1-5 , FIGS. 6-24 can provide counterflow flow lines for counterflowing fluid from a downstream module (e.g., module 4 ) to an upstream module (e.g., module 3 ).
FIG. 6 is an example of an apparatus having particular utility for the hospitality sector of business. Line 141 is a counterflow line from module 4 to module 3 . Line 142 is a counterflow line from module 3 to module 2 . Line 143 is a counterflow line from module 2 to module 1 . Lines 144 , 145 and valved drain lines to sewer 128 . Line 146 is a valved recirculation line to hopper 14 . As with FIGS. 1-5 , FIG. 6 employs tanks 24 , 26 . Flow line 161 drains module 5 to tank 24 . Line 147 transmits fluid from tank 24 to tank 26 . Flow line 148 has pump 149 and transmits fluid from tank 26 to module 5 and/or hopper 14 via branch line 150 . Line 151 and pump 152 transmit fluid from tank 26 to module 4 . Alkali detergent at 153 is shown for addition to module 1 . Chlorine bleach is shown at 154 for addition to module 2 . Antichlor sour solution is shown at 155 for addition to module 5 .
For exemplary parameters of FIG. 6 , total time is 17.5 minutes. Transfer time of fabric articles, linens, laundry from one module to the next module (e.g., module 1 to module 2 or module 2 to module 3 , etc.) is 180 minutes. Batches of laundry, linens, fabric articles per time is about 17 batches per hour. Water consumption is 0.3 to 0.4 gallons per pound of laundry (2.5 to 3.3 liters per kilogram of laundry). Average pulse flow water quantity is 105 gallons (or 398 liters) per batch of laundry. In FIG. 7 , washer 10 C replaces chlorine bleach at 154 with hydrogen peroxide at 156 . Water can be added to tank 26 via source 157 and valved flow line 158 . In FIG. 8 , sanitizing sour at 159 is added to module 4 . In FIG. 8 , chlorine bleach 154 and hydrogen peroxide 156 are not present.
FIGS. 9-11 show an arrangement similar to FIGS. 6-8 but for a seven module tunnel washer apparatus 10 D wherein alkali detergent 153 is added to modules 1 , 2 with chlorine bleach 154 is added to module 3 and antichlor sour 155 to module 7 . In FIG. 10 , hydrogen peroxide 156 replaces chlorine bleach 154 . In FIG. 11 , sanitizer sour 160 is added to module 4 and sour solution 161 to module 7 while chlorine bleach and hydrogen peroxide are not present. In FIGS. 9-11 , counterflow lines are provided as with FIGS. 1-8 . One of the counterflow flow lines can be provided with pump 162 . Pump 162 can be in the counterflow flow line that transmits fluid from module 5 to module 4 . In FIGS. 9-11 , exemplary parameters are 14.6 minutes total time. Transfer time is 129 seconds. Batches per time equals 29 per hour. Water consumption is 0.3 to 0.4 gallons per pound of fabric articles (e.g., linens) or between 2.5-3.3 liters per kilogram. Pulse flow water liquor ratio is about 0.7 gallons per pound or 5.8 liters per kilogram. Average pulse flow water per batch is 105 gallons (397.5 liters).
FIGS. 12-14 show a washing apparatus similar to FIGS. 6-8 , but for an eight module washer 10 E. In FIGS. 12-14 , alkali detergent 153 is added to modules 1 , 2 . Chlorine bleach 154 is added to modules 3 , 4 and antichlor sour solution 155 to module 8 . In FIG. 13 , hydrogen peroxide 156 replaces the chlorine bleach 154 of FIG. 12 . In FIG. 14 , neither chlorine bleach 154 nor hydrogen peroxide 156 are used. Instead, sanitizing sour 159 is added to module 5 and sour solution 160 is added to module 8 . In FIGS. 12-14 , the counterflow lines are provided as with FIGS. 1-11 . One of the counterflow lines can be provided with pump 163 . Pump 163 can be in the counterflow line that transmits fluid from module 5 to module 4 .
FIGS. 15-16 show a ten module washing apparatus 10 F wherein pump 164 is in a counterflow line that transmits fluid from module 6 to module 5 .
FIGS. 17-19 show a twelve module washing apparatus 10 G wherein pump 165 is in a counterflow line from module 8 to module 7 . Pump 166 is in a counterflow line from module 4 to module 3 .
FIG. 20 shows a twelve module washing apparatus 10 H with an alternate pulse flow that uses two or more pulse flow streams and having long distance incompatibility avoidance for incompatible batches, pH sensing and conductivity sensing. In cases of white vs. colored fabric articles separated by empty pocket, an alternate pulse flow can be provided which provides separate streams of counterflow water so that the counterflow for the colored downstream linen does not contact the white linen at the front of the machine.
In FIG. 20 , two finish modules 11 , 12 are provided for optional starching. In FIG. 20 , tank 26 has pumps 149 , 152 and a third pump 167 . Line 151 branches at tee fitting 168 to lines 169 (discharging to module 8 ) and line 170 (discharging to module 9 ). Third pump 167 discharges to line 169 which has tee fittings at 171 , 172 , 173 . Valves are provided on opposing sides of tee fittings 172 , 173 so that hot water at 174 or tempered water at 175 can be selectively added to an alternate pulse flow header 176 or 177 . Alternate pulse flow header 176 enables water to be added to any one of modules 1 , 2 , 3 , 4 , 5 , 5 , 6 , 7 or 8 via a valved branch line 178 . As with FIGS. 1-5 , each module has a valved drain line and counterflow lines that connect a module (e.g., module 9 ) to a previous module (e.g., module 8 ). Line 177 has valved branch lines 180 , 181 , 182 .
An incompatible batch normally refers to a classification of linen which can be a different color than linen in downstream modules. For example, if red table linen is in modules 1 to 10 and the next classification of linen to enter the tunnel is white, the counterflow water used for the red table linen cannot be used for the white linen. Different counterflow streams are thus provided, described herein as “alternate pulse flow”. Because the press water extracted from the red table linen normally flows to the PulseFlow tank, this water has to be diverted to sewer using the valves 60 (Closed) and 61 (Open), as seen in FIG. 4B . The programming feature in the controller to operate these valves is called “Long Distance Incompatibility”. FIGS. 20-24 all provide such “alternate pulse flow” with multiple sources of counterflow or multiple pulse flow headers.
In FIG. 21 , a twelve module washing apparatus 10 I provides an example of long distance incompatibility avoidance wherein white linen or textile articles follow colored linen or textile articles, an empty pocket provided at module 6 . Colored textile articles or colored linen are in modules 7 - 12 in FIG. 21 . White linen or textile articles are in modules 1 - 5 in FIG. 21 .
FIG. 21 is similar to FIG. 20 , but provides an “empty pocket” (at module 6 in FIG. 21 ) which separates colored fabric articles from white fabric articles.
In FIG. 22 , washing apparatus 10 J provides an eight module washing apparatus wherein low temperature washing follows high temperature washing of white linen or white textile articles. In FIG. 22 , modules 1 and 2 are low temperature (e.g., 50° C.). Modules 2 - 8 are high temperature (e.g. 75° C.).
In FIG. 23 , modules 1 - 3 are low temperature white linen or textile articles wherein modules 4 - 8 are high temperature white linen or textile articles. In FIG. 24 , colored linen articles in modules 1 - 2 follow white linen articles in modules 3 - 8 .
In FIGS. 22 , 23 , 24 an additional tank 185 is provided. Tank 26 is for white fabric articles while tank 185 is used for colored fabric articles. Each tank 26 , 185 has a water or fluid source 157 . Header 186 receives flow from tank 185 and pump 188 . Header 187 receives flow from tank 185 and pump 189 . Line 190 receives flow from tank 26 and pump 152 . Line 191 receives flow from tank 26 and pump 149 . Line 190 transmits fluid from tank 26 to hopper 14 . Header or line 191 connects with each of a plurality of branch flow lines 192 . Each branch flow line 192 discharges to a module 1 , 2 , 3 , 4 , 5 , 6 , 7 or 8 . The branch flow lines 192 can be valved flow lines.
Header or flow line 186 connects with each of a plurality of branch flow lines 193 . Each branch flow line 193 can be valved. Each branch flow line 193 discharges to a module 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 . In FIG. 22 , low temperature white linens follow high temperature white linens. In the example of FIG. 22 , only modules 1 , 2 are low temperature (e.g., 50° C.). Modules 3 - 8 are high temperature (e.g., 70° C.).
In FIG. 23 , the same arrangement of FIG. 22 is shown but after a transfer where the low temperature of module 2 has transferred to module 3 and the low temperature of module 1 has transferred to module 2 .
FIG. 24 is similar to FIG. 22 but colored fabric articles replace the low temperature white fabric articles of FIG. 22 . The high temperature white fabric articles of modules 2 - 8 of FIG. 22 are just white fabric articles in FIG. 24 .
The following is a list of parts and materials suitable for use in the present invention.
PARTS LIST
Part Number
Description
1
module
2
module
3
module
4
module
5
module
6
module
7
module
8
module
9
module
10
module
10A
textile washing apparatus
10B
textile washing apparatus
10C
textile washing apparatus
10D
textile washing apparatus
10E
textile washing apparatus
10F
textile washing apparatus
10G
textile washing apparatus
10H
textile washing apparatus
10I
textile washing apparatus
10J
textile washing apparatus
11
tunnel washer
12
inlet end portion
13
outlet end portion
14
hopper
15
discharge
16
soiled linen arrow
17
arrow
18
arrow
19
press/extractor
20
shuttle
21
dryer
22
transport
23
finishing station
24
extractor reuse tank
25
linen/fabric articles
26
pulse flow tank
27
conductivity sensor
28
conductivity sensor
29
conductivity sensor
30
influent flow line
31
flow meter
32
valve
33
valve
34
valve
35
flow line
36
valve
37
flow line
38
pump
39
valve
40
flow meter
41
valve
42
valve
43
sewer
44
flow line
45
pump
46
valve
47
flow meter
48
flow line
49
pump
50
influent flow line
51
flow meter
52
tee fitting
53
flow line
54
flow line
55
valve
56
valve
57
valve
58
pump
59
valve
60
valve
61
valve
62
sewer
63
valve
64
valve
65
flow line
66
flow line
67
tee fitting
68
flow line
69
pump
70
flow meter
71
tee fitting
72
flow line
73
ironer
74
chest
75
roller
76
arrow
77
dotted line
78
arrow
79
cold water source
80
hot water source
81
flow line
82
Tee-fitting
83
valve
84
flow meter
85
valve
86
Tee-fitting
87
Tee-fitting
88
flow line
89
valve
90
flow line
91
valve
92
flow line
93
flow meter
94
valve
95
Tee-fitting
96
valve
97
Tee-fitting
98
valve
99
flow meter
100
flow line
101
pump
102
flow line
103
flow line
104
flow line
105
Tee-fitting
106
Tee-fitting
107
Tee-fitting
108
Tee-fitting
109
flow line
110
flow line
111
flow line
112
flow line
114
valve
115
valve
116
valve
117
valve
118
valve
120
chemical dispenser
121
water header
122
pump
123
fill valve
124
fill valve
125
fill valve
126
fill valve
127
flow line
128
sewer
129
drain valve
130
drain valve
131
drain valve
132
counterflow valve
133
counterflow valve
134
counterflow valve
135
counterflow valve
136
valve
137
valve
138
valve
139
valve
140
arrow
141
counterflow line
142
counterflow line
143
counterflow line
144
valved drain lines
145
valved drain lines
146
valved recirculation line
147
transmitter
148
flow line
149
pump
150
branch line
151
line
152
pump
153
alkali detergent
154
chlorine bleach
155
antichlor solution
156
hydrogen peroxide
157
fluid source
158
valved flow line
159
sanitizing sour
160
sour solution
161
flow line
162
pump
163
pump
164
pump
165
pump
166
pump
167
pump
168
tee fitting
169
flow line
170
flow line
171
tee fitting
172
tee fitting
173
tee fitting
174
hot water source
175
tempered water source
176
alternate pulse flow header
177
alternate pulse flow header
178
valved branch line
179
ph sensor
180
valved branch line
181
valved branch line
182
valved branch line
185
tank
186
header
187
header
188
pump
189
pump
190
flow line
191
flow line
192
branch flow line
193
counterflow flow line
All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise.
The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims. | A method of washing fabric articles in a tunnel washer that includes moving the fabric articles from the intake of the washer to the discharge of the washer and through multiple modules or sectors. Liquid can be counter flowed in the washer interior along a flow path that is generally opposite the direction of travel of the fabric articles in order to rinse the fabric articles. While counterflow rinsing, the flow rate can be maintained at a selected flow rate or flow pressure head. One or more booster pumps can optionally be employed to maintain constant counterflow rinsing flow rate or constant counterflow rinsing pressure head. A source of fresh, make-up water can be provided to adjust conductivity. Conductivity is monitored in at least one of the modules. Conductivity of fluid in the discharged fabric articles is monitored. Make up water is added to one or more modules before if the conductivity of water in the discharged fabric articles exceeds a threshold value. In one embodiment, one of the modules is an empty pocket that is drained of fluid when rinsing with counterflowing liquid. | 3 |
TECHNICAL FIELD
[0001] The present invention relates to a method and apparatus for forming a thin film, and more specifically, to an atomic layer deposition (ALD) apparatus and method capable of forming a thin film at an atomic level.
BACKGROUND ART
[0002] Thin films are used for various purposes such as a dielectric layer or an active layer of a semiconductor device, a transparent electrode of a liquid crystal display device, and an emission layer and a protective layer of an electroluminescent display device. However, with the development of technology, there is increasing need for a thin film having uniform thickness ranging from several nanometers to several tens of nanometers in an opto-electronic device and a display device, etc.
[0003] Typically, the thin film is formed by using a physical deposition method such as sputtering or evaporation, a chemical deposition method such as chemical vapor deposition, and an ALD method etc. In the ALD method, a thin film is formed by decomposing reactants with chemical substitution through a periodic supply of each reactant. The ALD method has benefits of good step coverage, producing a low impurity concentration, low-temperature-process adaptability and accurate controllability for a layer thickness, compared with other conventional deposition methods. Thus, the ALD method is regarded as a key technology in fabricating semiconductor elements for a memory such as a dielectric layer, a diffusion barrier layer and a gate dielectric layer.
[0004] In general, a halide-type source gas is widely used in the conventional ALD method. However, the halide-type source has drawbacks in that it erodes an apparatus and a deposition speed is slow. Recently, an ALD method using an organic metal source has been widely used. However, the ALD method using the organic metal source produces a high impurity concentration and a low thin film density.
[0005] In order to remove impurities and improve a thin film density, a plasma-applied ALD method in which a surface reaction speed is increased and the surface reaction is performed at a low temperature has been proposed. However, in the associated ALD apparatus, plasma is generated inside a reaction chamber, so that physical shock is directly imposed on the substrate and the thin film and may damage the thin film. Further, according to many reports, it is difficult to use an apparatus for controlling plasma energy, in the plasma-applied ALD method, and thus the thin film may not be uniformly formed due to plasma nonuniformity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a schematic diagram of a remote plasma atomic layer deposition apparatus using a DC bias according to an embodiment of the present invention;
[0007] FIG. 2 is a schematic cross sectional view of a shower head included in the apparatus of FIG. 1 ; and
[0008] FIG. 3 is a bottom view of the shower head included in the apparatus of FIG. 1 .
DETAILED DESCRIPTION OF THE INVENTION
Technical Goal of the Invention
[0009] The present invention provides a remote plasma ALD (atomic layer deposition) apparatus capable of minimizing thin film damage caused by plasma and forming more uniform thin film.
[0010] The present invention also provides a remote plasma ALD method capable of minimizing thin film damage caused by plasma and forming more uniform thin film.
Disclosure of the Invention
[0011] According to an aspect of the present invention, there is provided a remote plasma ALD using a DC bias, comprising: a reaction chamber having an inner space; a substrate supporting body on which a substrate on which a thin film is to be formed is loaded arranged at one side of the inner space of the reaction chamber; a remote plasma generating unit arranged outside of the reaction chamber to supply a remote plasma into the inner space of the reaction chamber; a DC bias unit controlling energy of the remote plasma; and a source gas supply unit supplying a source gas for forming the thin film into the reaction chamber.
[0012] According to another aspect of the present invention, there is provided a remote plasma ALD method using a DC bias, comprising: providing a reaction chamber having an inner space; loading a substrate on which a thin film is to be formed inside the reaction chamber; supplying a source gas to the reaction chamber; supplying a carrier gas to the reaction chamber; generating a remote plasma outside the reaction chamber; controlling energy of the remote plasma using the DC bias to capture or accelerate ions or electrons of the plasma; and accelerating radical generation in the source gas using the energy-controlled remote plasma to grow a thin film composed of a single atom layer compound on the substrate.
EFFECT OF THE INVENTION
[0013] In the plasma ALD apparatus according to the present invention, a remote plasma is used, and a flux of activated plasma particles is controlled by a DC bias.
[0014] The plasma is generated by a remote plasma generating unit using the DC bias arranged outside the reaction chamber and streams into the reaction chamber, so that it is possible to prevent direct shock to the substrate, unlike in the case where plasma is generated inside the reaction chamber, thereby preventing the substrate and the thin film from being damaged by the plasma.
[0015] Further, energy of the remote plasma can be controlled by adjusting the DC bias, so that a single atomic layer constituting an atomic layer thin film can be deposited by supplying appropriate energy to a source gas.
BEST MODE FOR CARRYING OUT THE INVENTION
[0016] The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown.
[0017] A plasma atomic layer deposition (ALD) apparatus and method according to the present invention are characterized in that a DC bias and a remote plasma are used, and thus, the apparatus and method will be referred to as “remote plasma ALD apparatus and method using DC bias.” The remote plasma ALD apparatus and method using a DC bias according to the present invention will now be described with reference to the accompanying drawings. However, the invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.
EMBODIMENTS
[0018] FIG. 1 is a schematic diagram of a remote plasma ALD apparatus 100 using a DC bias according to an embodiment of the present invention.
[0019] The remote plasma ALD apparatus 100 comprises an inner reaction chamber 10 for forming a thin film, a remote plasma generating unit 30 for generating plasma, a DC bias unit 50 for controlling the remote plasma, and a source gas supply unit 70 .
[0020] The inner reaction chamber 10 has an inner space in which a thin film is formed. A substrate supporting body 15 is arranged at one side in the inner space of the inner reaction chamber 10 . A substrate 16 on which a thin film is to be formed is loaded onto the substrate supporting body 15 . The substrate 16 may be composed of Si, and SiGe, Ge, Al 2 O 3 , GaAs or SiC.
[0021] The source gas supply unit 70 supplies a source gas used to form the thin film into the inner reaction chamber 10 . If the thin film to be grown on the substrate 16 is composed of a silicon compound such as silicon oxide, the corresponding source gas is supplied. The source gas supply unit 70 may comprise a shower head 70 a and a source gas supply tube 70 b connected to one end of the shower head 70 a to supply the source gas to the shower head 70 a . With the shower head 70 a described above, better uniformity of the thin film can be achieved over the entire surface of the substrate 16 compared with a conventional traveling method. The source gas supply unit 70 may be a ring type, a traveling type and another type not mentioned herein. As is well known to those skilled in the art, more than one source gas supply tube 70 b may be connected to the shower head 70 a , if necessary, to supply more than one type of source gas. In general, the source gas, especially an organic metal source gas, may contain various poisons. Thus, it is desirable that the shower head 70 a be composed of nickel, which is invulnerable to the poisons in the source gas, to extend the lifetime of the shower head 70 a . The remote plasma ALD apparatus 100 also includes a carrier gas supply unit 25 connected to the inner reaction chamber 10 , to supply a carrier gas that carries the source gas into the inner space of the inner reaction chamber 10 . Further, the remote plasma generating unit 30 is arranged outside the inner reaction chamber 10 and connected to the carrier gas supply unit 25 . The remote plasma generating unit 30 supplies the remote plasma into the inner space of the inner reaction chamber 10 . The plasma carries particles activated through an ionization process to the substrate 16 to improve adhesiveness of the thin film material to be deposited and enhance uniformity when growing the thin film.
[0022] As shown in FIG. 1 , when the source gas supply unit 70 includes the shower head 70 a , the shower head type of remote plasma is preferably provided to supply the substrate 16 with the source gas and the remote plasma, which are sprayed from the shower head 70 a , via separated paths.
[0023] FIG. 2 is a schematic cross sectional view of the shower head 70 a . The path S of the source gas and the path P of the remote plasma are separated from each other in the shower head 70 a . Spray holes 72 having a predetermined diameter are provided on the bottom of the shower head 70 a to spray the source gas supplied through the source gas supply tube 70 b into the inner reaction chamber 10 . In addition, perforation holes 74 are provided to supply the remote plasma. The shower head 70 a is connected to the carrier gas supply unit 25 , which supplies the plasma generated by the remote plasma generating unit 30 to the substrate 16 via the path P.
[0024] Referring back to FIG. 1 , the DC bias unit 50 for controlling energy of the remote plasma is connected to the carrier gas supply unit 25 . The DC bias unit 50 comprises two counter electrodes 50 a and 50 b . When the first electrode 50 a is set to a positive voltage, the second electrode 50 b is set to a negative voltage, and vice versa. Voltages applied to the counter electrodes 50 a and 50 b are controlled to adjust the DC bias, thereby controlling the flux of activated plasma particles.
[0025] By using the DC bias unit 50 of the apparatus 100 , energy of ions and electrons generated in the RF plasma can be controlled so that the intensity of the plasma and the movement of electron in the plasma can be controlled. Therefore, a single atom layer constituting an atomic layer thin film can be deposited by supplying appropriate energy to the source gas. The thin film to be grown on the substrate 16 can be composed of a single crystal, polycrystalline or amorphous compound.
[0026] A method of depositing a thin film on the substrate 16 using the remote plasma ALD apparatus 100 will now be described.
[0027] The substrate 16 is loaded on the substrate supporting body 15 inside the inner reaction chamber 10 , and the source gas is then supplied into the inner reaction chamber 10 via the source gas supply unit 70 . Additionally, the carrier gas is supplied to the inner reaction chamber 10 via the carrier gas supply unit 25 . The remote plasma is generated in the remote plasma generating unit 30 arranged outside the inner reaction chamber 10 , and energy of the remote plasma is controlled using the DC bias produced by the DC bias unit 50 , which is further included in the carrier gas supply unit 25 . Under this arrangement, ions and electrons in the plasma are captured or accelerated. With the energy controlled remote plasma, a source gas is promoted to generate a radical so that a thin film composed of a single atomic layer compound is grown on the substrate 16 .
[0028] As described above, the ALD apparatus and method according to the present invention uses remote plasma. The remote plasma, which is generated by the remote plasma generating unit 30 arranged outside the inner reaction chamber 10 and streams into the inner reaction chamber 10 with energy controlled by the DC bias unit 50 , does not impose a direct shock on the substrate 16 and the thin film, contrary to the conventional methods in which the plasma is generated inside the inner reaction chamber 10 . Therefore, damage to the substrate 16 and the thin film caused by the plasma can be minimized. Further, considering the lifetime of the remote plasma deposited inside the inner reaction chamber 10 , the DC bias is applied to an RF plasma so that a remote plasma not affected by a frequency band of the RF plasma, i.e., 13.56 MHz can react with a precursor in the inner reaction chamber 10 . As a result, it is possible to stably generate the remote plasma.
[0029] An exemplary ALD method with the remote plasma ALD apparatus using the DC bias according to the present invention may include, but is not limited to, a method of periodically supplying a remote H 2 , N 2 , H 2 +N 2 , O 2 , or NH 3 plasma, an organic metal source, and a metal source to deposit metal, metal oxide or metal nitride on the substrate 16 . Accordingly, it is possible to deposit various compounds such as single crystal, amorphous and polycrystalline compounds to form a single atomic layer on a substrate.
[0030] While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. The exemplary embodiments should be considered in descriptive sense only and not for purposes of limitation. Therefore, the scope of the invention is defined not by the detailed description of the invention but by the appended claims, and all differences within the scope will be construed as being included in the present invention. | A conventional plasma applied ALD apparatus has a problem in that physical shock is directly imposed on a substrate and a thin film thereby damaging the thin film. Further, many reports have said that since an apparatus for controlling plasma energy is not arranged well, the thin film is not formed uniformly due to plasma nonuniformity. Therefore, there is provided a remote plasma atomic layer deposition apparatus using a DC bias comprising: a reaction chamber having an inner space; a substrate supporting body on which a substrate on which a thin film is to be formed is loaded arranged at one side of the inner space of the reaction chamber; a remote plasma generating unit arranged outside of the reaction chamber to supply a remote plasma into the inner space of the reaction chamber; a DC bias unit controlling energy of the remote plasma; and a source gas supply unit supplying a source gas for forming the thin film into the reaction chamber. | 2 |
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to heat exchangers for power generating systems. A specific embodiment relates to recuperators for turbomachinery. The present invention also relates to microturbine power generating systems, which are small, multi-fuel, modular distributed generation units.
[0002] Although the recuperator of the present invention can be used with stationary microturbines, with other turbomachinery (such as turbomachinery used for automotive and air transportation), and with other power generating systems such as fuel cells, the recuperator is described here for convenience primarily in connection with microturbines. Microturbine power generating systems generally includes a combustor, a turbine stage, a compressor stage and an electrical generator. A microturbine power generating system may also include a recuperator for transferring heat from hot exhaust gas leaving the turbine stage to compressed air entering the combustor. Transferring the heat raises the temperature of the air entering the combustor and cools the exhaust gas leaving the turbine stage. Raising the temperature of the compressed air enhances combustion and increases efficiency of the system.
[0003] There are potential problems associated with the recuperator. One potential problem arises from thermal stresses in the recuperator. The turbine exhaust gas entering the recuperator is hotter than the exhaust gas leaving the recuperator. Consequently, the front face of the recuperator is hotter than the exit face. The resulting thermal stresses can reduce the operating life of the recuperator.
[0004] Another potential problem is associated with the buildup of combustion products in the recuperator. As the exhaust gas is passing through the recuperator, combustion products in the exhaust gas can condense and build up on cooler heat transfer surfaces of the recuperator. The buildup can decrease heat transfer efficiency. The buildup can also restrict the flow of exhaust gas and thereby reduce system efficiency. The recuperator may be cleaned periodically, but the periodic cleaning would increase the cost of maintaining the microturbine power generating system.
SUMMARY OF THE INVENTION
[0005] The present invention may be regarded as a recuperator movable between a first position and a second position in a power generating system such as a microturbine. When the recuperator is in the first position, a gas side inlet of the recuperator is coupled to a turbine exhaust outlet of the microturbine. When the recuperator is in the second position, a gas side outlet of the recuperator is coupled to the turbine exhaust outlet, whereby the direction of gas flow inside the recuperator is reversed. Reversing the gas flow direction reduces the total amount of time that the hotter sections of the recuperator are exposed to higher temperatures, thereby extending the life of the recuperator. Reversing the gas flow direction also allows deposited combustion products to be removed from the heat transfer surfaces of the recuperator, resulting in a self-cleaning feature that reduces maintenance of the power generating system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] [0006]FIG. 1 is a block diagram of a power generating system according to the present invention, the power generating system including a recuperator;
[0007] [0007]FIG. 2 is an illustration of a core of the recuperator;
[0008] [0008]FIGS. 3 a and 3 b are illustrations of the recuperator in first and second positions; and
[0009] [0009]FIG. 4 is a flowchart of a method of using the recuperator.
DETAILED DESCRIPTION OF THE INVENTION
[0010] [0010]FIG. 1 shows a power generating system 10 including a compressor 12 , a turbine 14 and an electrical generator 16 cantilevered from the compressor 12 . The compressor 12 , the turbine 14 and the electrical generator 16 are rotated by a single common shaft 18 . Although the compressor 12 , turbine 14 and electrical generator 16 may be mounted to separate shafts, the use of the single common shaft 18 adds to the compactness and reliability of the power generating system 10 .
[0011] The shaft 18 may be supported by self-pressurized air bearings such as foil bearings. Foil bearings eliminate the need for a separate bearing lubrication system and reduce the occurrence of maintenance servicing.
[0012] Air is compressed by the compressor 12 , and the compressed air is circulated through air side passages of a recuperator 22 . Compressed air leaving the air side passages of the recuperator 22 is supplied to a combustor 24 .
[0013] Fuel is also supplied to the combustor 24 . Either gaseous or liquid fuel may be used. Choices of fuel include diesel, flare gas, wellhead natural gas, waste hydrocarbon fuel streams, gasoline, naphtha, propane, JP-8, methane, natural gas and other man-made gases.
[0014] The flow of fuel to the combustor 24 is controlled by a flow control valve 26 . The fuel is injected into the combustor 24 by an injection nozzle 28 .
[0015] Inside the combustor 24 the fuel and compressed air are mixed and ignited by an igniter 27 in an exothermic reaction. Hot, expanding gases resulting from combustion in the combustor 24 are directed to an inlet nozzle 30 of the turbine 14 . The inlet nozzle 30 may have a fixed geometry. The hot, expanding gases resulting from the combustion are expanded through the turbine 14 , thereby creating turbine power. The turbine power, in turn, drives the compressor 12 and the electrical generator 16 . For transportation applications, the generator may be reduced in size or eliminated, and the excess resulting power supplied to a drive train.
[0016] Turbine exhaust gas is passed through gas side passages of the recuperator 22 . Inside the recuperator 22 , heat from the turbine exhaust gas in the gas side passages is transferred to the compressed air in the air side passages. In this manner, some heat of combustion is recuperated and used to raise the temperature of the compressed air en route to the combustor 24 . After surrendering part of its heat, the turbine exhaust gas exits the recuperator 22 . Additional heat recovery stages may be added onto the power generating system 10 . A muffler 32 reduces the noise created by the turbine exhaust gas leaving the recuperator 22 .
[0017] The generator 16 may be a ring-wound, two-pole toothless (TPTL) brushless permanent magnet machine having a permanent magnet rotor 34 and stator windings 36 . The rotor 34 is attached to the shaft 18 . When the rotor 34 is rotated by the turbine 14 , an alternating current is induced in the stator windings 36 . Speed of the turbine 34 can be varied in accordance with external energy demands placed on the system 10 . Variations in the turbine speed will produce a variation in the frequency of the alternating current generated by the electrical generator 16 . Regardless of the frequency of the ac power generated by the electrical generator 16 , the ac power can be rectified to dc power by a rectifier 38 , and then chopped by a solid-state electronic inverter 40 to produce ac power having a fixed frequency. Accordingly, when less power is required, the turbine speed can be reduced without affecting the frequency of the ac output.
[0018] Use of the rectifier 38 and the inverter 40 allows for wide flexibility in determining the electric utility service to be provided by the power generating system 10 of the present invention. Because any inverter 40 can be selected, frequency of the ac power can be selected by the consumer. If there is a direct use for ac power at wild frequencies, the rectifier 38 and inverter 40 can be eliminated.
[0019] A controller 42 controls the turbine speed by controlling the amount of fuel flowing to the combustor 24 . The controller 42 uses sensor signals generated by a sensor group 44 to determine the external demands upon the power generating system 10 and then controls the fuel valve 26 accordingly. The sensor group 44 could include sensors such as position sensors, turbine speed sensors and various temperature and pressure sensors for measuring operating temperatures and pressures in the system 10 . Using the aforementioned sensors, the controller 42 can control both startup and optimal performance during steady state operation.
[0020] Reference is now made to FIG. 2. The recuperator 22 includes a heat exchanger core 50 having a standard construction. Air and gas side passages 52 and 54 are formed within the heat exchanger core 50 . The heat exchanger core 50 may be made of a stack of plates that form the air and gas side passages 52 and 54 .
[0021] Compressed air is supplied to an air inlet manifold 56 , which distributes the compressed air to the air side passages 52 in the heat exchanger core 50 . Air leaving the air side passages 52 is collected by an air outlet manifold 58 . The air manifolds 56 and 58 may be formed integrally with the heat exchanger core 50 . For example, the air manifolds 56 and 58 may be formed by the plates.
[0022] The turbine exhaust gas stream enters a first face 60 of the heat exchanger core 50 , flows through the gas passages 54 in the core 50 , and exits from a second face 62 of the heat exchanger core 50 . As the air flows across the core 50 , heat is transferred from the exhaust gas to the compressed air. However, as the turbine exhaust gas is passing through the gas side passages 54 , combustion products in the turbine exhaust gas can condense and build up on cooler sections of the gas side passages 54 . This buildup can decrease heat transfer efficiency. The buildup can also restrict the flow of turbine exhaust gas and thereby reduce system efficiency.
[0023] The heat exchanger core 50 can be rotated by 180 degrees about a pivot point A, whereby the positions of the inlet and outlet manifolds 56 and 58 are reversed. A direction of rotation is indicated by the arrow R. When the core 50 is rotated by 180 degrees, the air and gas flow directions are reversed. Air flows into the air outlet manifold 58 and out of the air inlet manifold 56 . Turbine exhaust gas enters the second face 62 of the heat exchanger core 50 and exits from the first face 60 . Reversing the gas flow direction allows deposited combustion products to be removed from the heat transfer surfaces of the recuperator 22 . Reversing the gas flow direction also reduces the total amount of time that the hotter sections of the recuperator 22 are exposed to higher temperatures, thereby extending the life of the recuperator 22 .
[0024] Reference is now made to FIGS. 3A and 3B. The recuperator 22 further includes a casing 64 for the heat exchanger core 50 . The casing 64 has external insulation (not shown) and mounting brackets 66 .
[0025] The recuperator 22 is mounted on a mounting stand 68 . The stand 68 includes mounting pins 70 that are pivotally attached to the mounting brackets 66 . The mounting stand 68 allows the recuperator 22 to be rotated about the axis A, which extends through the mounting pins 70 . The recuperator 22 can be rotated between a first position (shown in FIG. 3 a ) and a second position (shown in FIG. 3B). Rotating the recuperator 22 from the first position to the second position (or vice versa) causes the air and gas flow directions inside the recuperator 22 to be reversed.
[0026] The casing 64 also provides a ducting interface for the recuperator 22 . The ducting interface includes a gas side inlet flange 72 , a gas side outlet flange 74 , an air inlet flange 76 , and an air outlet flange 78 .
[0027] When the recuperator 22 is in the first position, the ducting interface flanges are attached as follows. The air inlet flange 76 is connected to a flange 80 on a first duct 82 , which places the air inlet manifold 56 in fluid communication with an outlet of the compressor 12 . The air outlet flange 78 is connected to a flange 84 on a second duct 86 , which places the air outlet manifold 58 in fluid communication with an air inlet of the combustor 24 . The gas inlet flange 72 is connected to a flange 88 on a third duct 90 , which places the bottom face 60 of the heat exchanger core 50 in fluid communication with an exhaust outlet of the turbine 14 . The gas outlet flange 74 is connected to a flange 92 on a fourth duct 94 , which places the top face 62 of the heat exchanger core 50 in fluid communication with an inlet of the muffler 32 .
[0028] Additional reference is now made to FIG. 4. After the recuperator 22 has been used over a period of time, the flanges 72 , 74 , 76 and 78 of the ducting interface are disconnected (step 102 ), and the recuperator 22 is rotated from the first position to the second position (step 104 ). This step may be accomplished in one of several ways. The recuperator 22 can be shaped so as to be rotatable in-situ on mounting pins 70 , without requiring any movement of flanges 88 or 92 relative to one another or to the mounting stand 68 . Or, mounting pins 70 can be slideably attached to mounting stand 68 or mounting brackets 66 , thereby allowing recuperator 22 to be slid out from between flanges 88 and 92 , rotated on mounting pins 70 , and re-inserted in reverse-flow position between flanges 88 and 92 . Alternatively, the fourth duct 94 and flange 92 could be removed from the system 10 ; the recuperator 22 detached from the other ducts of the system 10 , lifted, rotated, replaced on flange 88 in reverse-flow position; and the fourth duct 94 and flange 92 remounted in the system 10 . This latter approach, of course, would allow the use of a mounting mechanism that does not require mounting pins 70 that are pivotally attached to mounting brackets 66 . Still other approaches can be used.
[0029] The recuperator 22 may have any or all of the following design features: air inlet and outlet flanges 76 and 78 that are located symmetrically or near-symmetrically with respect to the axis of rotation A; gas inlet and outlet flanges 72 and 74 that are located symmetrically or near-symmetrically about the axis A of rotation; and symmetrically-opposed flanges that have the same bolt patterns. The system 10 may have any or all of the following design features: air inlet and outlet ducts 82 and 86 that are sized similarly; gas inlet and outlet ducts 90 and 92 that are sized similarly; and symmetrically-opposed flanges that have the same bolt patterns. Each of these design features reduces the amount of work needed to disconnect and reconnect the recuperator 22 in the system 10 .
[0030] Following step 104 , the flanges 72 , 74 , 76 and 78 of the mounting interface are reconnected (step 106 ). The air inlet flange 76 is reconnected to the flange 84 on the second duct 86 , which places the air inlet manifold 56 in fluid communication with an air inlet of the combustor 24 . The air outlet flange 78 is connected to the flange 80 on the first duct 82 , which places the air outlet manifold 58 in fluid communication with the compressor outlet. The gas inlet flange 72 is connected to the flange 92 on the fourth duct 94 , which places the bottom face 60 of the heat exchanger core 50 in fluid communication with the muffler inlet. The gas outlet flange 74 is connected to the flange 88 on the third duct 90 , which places the top face 62 of the heat exchanger core 50 in fluid communication with the turbine exhaust outlet.
[0031] The power generating system 10 is operated (Step 108 ). Previously hotter sections of the recuperator 22 now become subjected to cooler temperatures, thereby extending the useful life of the recuperator 22 . Additionally, combustion products that were deposited on the gas passages 54 near the colder gas outlet (prior to reversal) are now near the hotter gas inlet (after reversal). Further operation of the turbine 14 causes the deposited products near the gas inlet to be burned off and removed. Resulting is a self-cleaning feature of the recuperator 22 .
[0032] After the recuperator 22 has been operated over an additional period of time, the recuperator 22 may be rotated back to the first position. The position of the recuperator 22 can be changed at any time. For example, the recuperator position could be changed halfway through the operating life, or the recuperator position could be changed whenever the microturbine power generating system 10 is overhauled.
[0033] Thus disclosed is a recuperator that can be rotated so that gas side passages are reversed. Reversing the gas side passages allows deposited combustion products to be removed and thereby improves heat transfer efficiency and exhaust gas through-flow. Reversing the gas side passages also reduces overall thermal stresses, which allows creep criteria to be relaxed (hotter sections of the core are designed by creep criteria; the creep criteria accounts for steady-state and transient temperature stresses in the core), the recuperator life to be extended, or thinner materials to be used to produce a smaller, lighter, lower cost recuperator.
[0034] The present invention is not limited to the specific embodiments disclosed above. For example the heat exchanger core could have a crossflow configuration instead of a counterflow configuration. An axis of rotation might be chosen such that the gas flow direction is reversed but the airflow direction is not reversed. The recuperator could be designed such that only the top and bottom faces of the heat exchanger core are rotated (and the inlet and outlet manifolds are not rotated). Configuration, geometry and dimensions of the recuperator will depend upon the intended application.
[0035] The recuperator interfaces may or may not be connected to ducts. Instead, certain recuperator interfaces may be mounted directly to flanges on the combustor, muffler and turbine. The heat exchanger core of the recuperator may be a prime surface heat exchanger core or an extended surface (i.e., plate fin) heat exchanger core.
[0036] In addition, the recuperator of the present invention could be used in a power generating system that does not use a turbomachine, such as a fuel cell power generating system.
[0037] Therefore, the present invention is not limited to the specific embodiments disclosed above. Instead, the present invention is construed according to the claims that follow. | A recuperator movable between a first position and a second position in or relative to a power generating system. When the recuperator is in the first position, a gas side inlet of the recuperator is coupled to a turbine exhaust outlet of the turbomachine. When the recuperator is in the second position, a gas side outlet of the recuperator is coupled to the turbine exhaust outlet, whereby the direction of gas flow inside the recuperator is reversed. Reversing the gas flow direction extends the life of the recuperator by reducing the total amount of time that the gas inlet face is exposed to high temperatures. Reversing the gas flow direction also allows for the removal of condensation of exhaust gas byproducts on cooler passage surfaces of the recuperator gas side. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to ascertain quickly the subject matter of the technical disclosure. The abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 C.F.R. 1.72(b). | 5 |
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
This patent application is a continuation of pending PCT Patent Application No. PCT/EP2011/072215, filed Dec. 8, 2011, which claims the benefit of German Application No. 102011010809.2, filed Feb. 9, 2011, the entire teachings and disclosure of which are incorporated herein by reference thereto.
FIELD OF THE INVENTION
The subject-matter concerns a charging station and a method for securing a charging process of a vehicle, in particular an electric vehicle, at a charging station.
BACKGROUND OF THE INVENTION
The use of electric vehicles promises a solution to many problems presently associated with private transport: the power necessary to drive these can be created in an environmentally-friendly manner, no exhaust gases are produced by the actual vehicle, the noise level is reduced and the electric drive itself in principle allows a higher efficiency than an engine relying on the combustion of fossil fuels.
In order for electric vehicles to be more widely used, however, simple and geographically widespread opportunities must be provided for energy charging, similar to the familiar filling station network for liquid fuels. This also raises questions of deducting a payment and securing the charging process. At present, although an infrastructure for a power supply is at least geographically broadly in place, the energy consumption from a plug socket cannot be easily broken down by respective user and determined promptly, if necessary limited, and billed in situ.
In order to make power filling stations that can be used by anyone, that is to say publicly accessible charging stations, practical, these must be as easy to operate as petrol pumps for liquid fuels and also allow the similar possibility of limitation and billing for the charging. From the point of view of the vehicle user, therefore, as little as possible should change.
With known safety mechanisms that prevent the connector being pulled out, control of the mechanical interlocking takes place from the vehicle. The charging station also monitors if the connector has been plugged into the vehicle. When the connector is pulled out, the charging current is interrupted so that there is no danger from the charging connector as a result of the high electrical potential present on this.
However, this can also lead to a deliberate pulling out of the charging connector from the vehicle resulting in an interruption to the charging process. In particular in the event that the charging process has already been paid for prior to charging this should be avoided. In this case the user also wants the vehicle to charge at the charging station for the duration paid for. This is of particular relevance when charging with direct current. There is as yet no calibrated method with which during charging with direct current the quantity of energy obtained can be measured. Rather, when charging with direct current a charging time is measured. It must therefore be ensured that the charging time previously paid for is actually used to charge the vehicle.
SUMMARY OF THE INVENTION
For the stated reasons, the object of the subject-matter was to provide a method for charging a vehicle, including charging-station side securing of the charging process.
This object is achieved according to a first aspect by a method according to the teaching herein.
It is proposed that on the charging-station side a random or pseudorandom first release code can be output to the user. The first release code can be a sequence of numbers or a sequence of characters or another code. A release code is pseudorandom if it is not generated according to a particular pattern, but cannot be predicted in advance by a potential aggressor. This can for example also be a code from a ring buffer. The first release code can also be generated by a random generator.
Once the first release code has been output, on the charging-station side the charging current can be released. Preferably, prior to release of the charging current, a further check is made that the charging cable is correctly inserted in the vehicle. This is necessary if it has to be ensured that no danger to the user results from the charging cables. Once the charging has been released, the charging process takes place. This is preferably determined by a duration which the user decides on and pays for in advance. This applies in particular for a charging process with direct current.
During the charging process or at the end of the prepaid duration of the charging process the user will want to be able to remove the charging cable from the vehicle. For this reason it is proposed that a second release code input by the user is received on the charging-station side. Preferably the user will have noted the first release code, output previously, or this will have been indicated to him by the charging station. Then the user can enter the second release code, which is identical to the first release code.
In order to check that the second release code corresponds to the first release code, on the charging-station side the first release code is compared with the second release code. For this it is necessary that the first release code output on the charging-station side is stored in the charging station. This storage is preferably secured against unauthorized access. Here the first release code can for example be stored in an encrypted manner in the charging station. The comparison takes place by checking if the first release code is identical to the second release code input.
If the two release codes are identical, on the charging-station side the charging current is interrupted. The charging process can then be ended.
Inputting the second release code and comparing the second release code with the first release code output, ensures that only the person who initiated the charging process can interrupt the charging process. Only this user was made aware of the first release code.
According to an advantageous exemplary embodiment it is proposed that prior to the step of release of the charging current on the charging-station side an interlocking signal bringing about an interlocking of a charging cable to the vehicle is sent to the vehicle.
This can take place wirelessly, for example via WLAN, Bluetooth, ZigBee, infrared, Near Field Communication or similar. It is also possible for the communication to take place via the charging cable itself. Here, for example, it is possible, that the charging cable apart from the wires that are necessary for power transmission also has wires that are used for communication. There may be eight of these wires, for example, with which communication with the CAN-Bus of the vehicle can take place. It is also possible for the communication to take place via the power line. For this a Power-Line-Communication (PLC) protocol can preferably be used.
It is also proposed that on the charging-station side a check is made that the vehicle has correctly responded to the interlocking signal and that the charging cable has actually interlocked. This can take place by the vehicle sending the charging station a confirmation signal that the charging cable has interlocked with the vehicle. Receipt of this confirmation signal can be monitored in the charging station. Only once the signal has been received does release of the charging current take place.
Once the process has ended, that is to say once the correct second release code has been input and the charging current has been interrupted, the charging cable must be unlocked from the vehicle. To this end it is proposed that after the step of interrupting the charging current, an unlocking signal is sent from the charging station to the vehicle. This can be transmitted to the vehicle in the same way as the interlocking signal. Then on the charging-station side a check can be made that the vehicle has actually unlocked the charging cable.
As already mentioned at the outset, prior to step a) on the charging-station side a charging time is determined. This is in particular the case when charging using direct current. When charging with a direct current, for example, a charging voltage of 400 volts and a charging current of 170 amperes can be used. In this case, as an example, within 30 minutes the battery will be 80% charged. With direct current charging charge regulation is performed by the charging station. Therefore the charging station must also be responsible for when the charging process is ended.
In particular if charging is dependent upon a charging time advance payment is desirable. It is therefore also proposed that prior to step a) on the charging-station side a payment process is performed. By way of example, a user can indicate a charging time and pay the necessary costs directly at the charging station. This payment can, for example, be made by credit card or an EC card. In this case a user must often enter a PIN code, in order to release the payment. Therefore the charging station in this case already has a display and a PIN pad. The first release code can for example be output via this display. Other outputs are also possible, however. And the PIN pad, which is also used for the payment process, can additionally be used for input of the second release code.
It is also proposed that steps a) to b) are performed at the start of a charging process. That is to say that the charging process is at least initiated by steps a) to b).
At the end of the charging process steps c) to e) are preferably performed. Thus a charging process can be ended by at least performing steps c) to e).
As already explained above payment for the charging process can take place in advance. This can take place for example by paying using a credit card or an EC card. In this case it is often advantageous if the user is issued with a payment receipt, including in respect of the tax regulations. For this reason the charging station often has a receipt printer. The receipt printer can in an advantageous manner also be used to output the first release code. Output can also be on a display, for example the display which is also used for payment. Finally, it is possible to inform the user of the release code by means of an electronic message. For example, it is possible for the user to indicate his mobile telephone number and for the first release code to be sent as a text message to his mobile telephone. An e-mail can also be used to send the user the first release code.
As soon as the user wishes to interrupt the charging process, he must input the second release code. It is proposed that the second release code is input on the charging-station side or vehicle side by the user. With charging-station side input, the abovementioned PIN pad can be used. It is also possible for the second release code to be sent by text message via a mobile telephone network to the charging station. In this case, at the charging station for example a mobile telephone number or another telephone number can be indicated to which the user can send a text message. It is also possible to use an app to send the second release code to the charging station.
Where input is on the vehicle side the user can for example use a keypad installed in a vehicle. Voice input on the vehicle side would for example also be possible. For this, by way of example, the speech recognition device of the integrated telephone on the vehicle side could be used. This device is already suitable for recognizing voice input of numbers. Thus it could also be used, for example, to input the second release code on the vehicle side.
Communication of the interlocking and/or unlocking signal and communication of the charging parameters and the charge regulation itself calls for a communications link and a communications protocol between the charging station and the vehicle. To this end it is proposed that communication between the charging station and the vehicle is via the charging cable, preferably using a CHADEMO protocol. The CHADEMO protocol is used for charge control and can also be used for communication of interlocking and unlocking signals. Communication between charging station and vehicle can also take place via PLC. Communication can take place via the power line. Communication can in particular take place via the DC line.
At the latest at the end of a charging process the charging station should be able to be used by other users. In order to prevent a user blocking a charging station, when this is no longer charging his vehicle, it is proposed that, upon expiry of the charging time, independently of the input of the second release code, the charging cable is unlocked on the vehicle side. For this, by way of example, the charging station can send the unlocking signal to the vehicle upon expiry of the charging time paid for, whereupon the vehicle unlocks the charging cable. The unlocked charging cable can for example be signaled to third parties by a visual notification. This ensures that the charging station can still be used even if a previous user has not released the charging cable by inputting the second release code, even though the charging time has expired.
As already explained above, the first release code can be generated in the charging station. This can take place, for example, by reading out from a ring buffer or by a random generator. On the other hand, it is also possible that in the charging station the first release code is received from a control centre. For this, by way of example, the charging station can send a request signal to the control centre, whereupon in the control centre a release code is determined, calculated or read out, and then transmitted to the charging station. Here the transmission can for example take place in an encrypted manner. Transmission by means of Powerline-Communication is similarly possible. On the other hand other transmission paths, such as for example via GSM, UMTS, WLAN, EDGE, Wi-Fi or similar are possible. Finally, cabled transmission such as via DSL and/or using the Internet protocol is possible.
A further subject matter is a charging station according to the teachings herein.
In this connection the charging station is provided with output means configured to output a random or pseudorandom first release code to a user. The output means can be a display, a receipt printer or similar. The output means can also be associated with communication means, allowing the first release code to be sent to a telephone or an e-mail account of a user. Then the first release code can be sent electronically to the user.
The charging station is also provided with control means configured to release the charging current. The control means can for example communicate via the charging cable, or by radio, with the vehicle. The control means are preferably configured to communicate via the CHADEMO protocol. The control means are further configured to release or to block the connection of the charging cable to a charge controller and the supply system. In this way, via the control means the charging current can be released or blocked. The control means can take the form of a suitably programmed microcomputer.
The charging station also has reception means, configured to receive a second release code input by a user. The reception means can for example consist of a number pad/character pad or a PIN pad, via which the user can manually input a numerical code/character code. The reception means can also be connected with the communication means, in order to receive a text message from the user, in which the user provides the second release code. Speech recognition means can also be provided allowing the user to input the second release code using his voice either directly at the charging station or via his telephone.
Comparison means can be provided, which compare the first release code with the second release code input. This can be a microprocessor, which allows a comparison between two sequences of numbers or two sequences of characters. For this purpose, the charging station can include a buffer memory which holds the first release code output until a comparison with the second release code takes place.
Finally, the comparison means have an operative connection with the control means. This operative connection serves at least to disconnect the charging current in the event of a positive comparison result. To this end a disconnection of the charge controller and of the charging cable from the supply network can take place.
Apart from the abovementioned means the charging station can also have additional communication means for communication with the vehicle. The communication means can be provided in particular for sending an interlocking and unlocking signal and for checking the interlocking of the charging cable to the vehicle. The communication means can also have an operative connection with the control means and so the communication means also allow communication with the vehicle, e.g. via the CHADEMO protocol or a PLC protocol or another protocol with which communication is possible via a power line or also a pilot line.
The features of this method and the device can be freely combined with one another. In particular, the features of the dependent claims, including in the absence of the features of the independent claims, on their own or freely combined with one another can also individually constitute an inventive step.
The abovementioned method can also be performed as a computer program or as a computer program stored on a storage medium. In this connection on the charging-station side a microprocessor can be suitably programmed to perform the respective process steps by means of a computer program.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in more detail in the following using a drawing showing an exemplary embodiment. The drawing shows as follows:
FIG. 1 a schematic view of a charging station according to an exemplary embodiment;
FIG. 2 a schematic view of a device for inputting a release code and for outputting a release code;
FIG. 3 a schematic view of a system with a charging station, a vehicle and a control centre;
FIG. 4 a detailed view of a vehicle-side interlocking device.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a charging station 2 . The charging station 2 is connected with a supply network 4 . A charging cable 6 arranged on the charging station 2 can be connected via a charge controller 8 with the energy supply network 4 . The charge controller 8 is controlled via a control means 10 and can in particular be driven by the control means 10 in order to release and disconnect the charging current.
Furthermore, in the charging station 2 a microprocessor 12 is provided, which on the one hand has communication means, in order to communicate with the vehicle via the charging cable 6 and on the other hand controls the communication between the control means 10 and an input/output terminal 14 .
Finally a communication means 16 can be connected with the control means 12 . The communication means 16 can on the one hand communicate wirelessly with the vehicle via a communication circuit such as for example a radio chip, e.g. using near-field communications. Furthermore, the communication means 16 can be configured to communicate via a cabled connection or wirelessly with a control centre, for example via DSL or via GSM/UMTS/EDGE/LTE.
The input/output terminal 14 is shown in more detail in FIG. 2 . As can be seen from this, the input/output terminal 14 has a PIN pad 20 . Via this PIN pad 20 a user can enter numbers and/or characters. In addition, a display 22 is provided, via which the user can check his entries and input requirements and other information can be communicated to the user.
The input/output terminal 14 has a card reader 24 , with which for example an EC card or a credit card can be read. A microprocessor (not shown) in the input/output terminal 14 thus allows a payment process with a credit card or an EC card to be controlled.
Finally, the input/output terminal 14 has a receipt printer 26 . The receipt printer 26 can on the one hand print a payment receipt and on the other a second release code on a receipt 28 .
FIG. 3 shows a system with a charging station 2 , a vehicle 30 and a control centre 32 . FIG. 3 also shows radio communication paths 34 and 36 . The radio communication path 34 allows for example radio communication between the charging station 2 or the communication means 16 arranged therein and the vehicle 30 , for example via WLAN, Bluetooth, ZigBee, DECT or similar.
The radio communication path 36 allows communication between the charging station 2 and the control centre 32 . For this purpose the radio communication path 36 can for example be a GSM-/UMTS-/LTE link. This connecting path may also, at least in part, use the Internet 38 .
FIG. 4 shows an interlocking device 40 , which can be arranged in a vehicle 30 , in order to interlock a charging cable 6 or a charging cable connector 6 a . The interlocking device 40 has contacts 42 , which are connected with the wires of the charging cable 6 . Here for example contacts 42 for power lines and contacts 42 for communication lines can be provided. The two contacts 42 shown serve merely as examples.
A communication means 44 is also provided in the interlocking device 40 and the communication means 44 can be a communication processor, which on the one hand can communicate with the vehicle 2 via the charging cable 6 , or can also communicate by radio via the radio communication path 34 .
Finally, mechanical latches 46 are provided, which can be operated by electric motor. The mechanical latches 46 can engage with grooves in the connector 6 a and thereby lock the connector 6 a in the interlocking device 40 . The latches can also unlock the connector 6 a , by being moved out of the grooves of the connector 6 a.
In order to charge the vehicle 30 a user drives the vehicle 30 to a charging station 2 . The charging station 2 is preferably a quick charging station, which charges using direct voltage. Here, a voltage of 400 Volts at a current of 170 Amperes can be applied via the charging cable 6 for example. The charging cable 6 is preferably installed in a fixed manner at the charging station 2 and has a connector 6 a , which can be inserted into the interlocking device 40 of the vehicle 30 . The user plugs the connector 6 a into the interlocking device 40 of the vehicle 30 and then goes to the input/output terminal 14 of the charging station 2 .
The user then uses the pin pad 20 , guided by notifications on the display 22 , to select a desired charging time, for example 30 minutes. The display 22 tells the user the costs of the charging process which he can then pay. To do so, by way of example, the user inserts his EC card into the card reader 24 and then enters his PIN code via the PIN pad 20 . After confirmation of the payment process a payment receipt 28 is printed out via the receipt printer 26 . In addition or on the payment receipt 28 a first release code can be printed.
It is also possible, by means of the communication means 16 to send a text message to a telephone of a user, containing the release code.
Once the payment process has been completed and the release code output, by means of the microprocessor 12 an interlocking signal is sent via the charging cable 6 to the vehicle 30 . Transmission via the radio communication path 34 is also possible. As soon as the interlocking device 40 or the communication means 44 of the interlocking device 40 receives the interlocking signal, they control the mechanical latches 46 so that they interlock the connector 6 a.
Successful interlocking of the connector 6 a is transmitted by the communication means 44 to the charging station 2 either via the charging cable 6 or the radio communication path 34 . Confirmation of the interlocking is received in the charging station in the microprocessor 12 . Once the interlocking has been confirmed, the microprocessor 12 controls the control means 10 in such a way that the control means releases the charging current via the charge controller 8 . To this end a connection between the energy supply network 4 and the charging cable 6 is created.
Then, the microprocessor 12 monitors how long the charging process lasts. If the charging time has elapsed without any user input, then an unlocking signal is transmitted to the vehicle 30 via the microprocessor 12 . Transmission takes place in the same way as transmission of the interlocking signal. The unlocking signal causes the connector 6 a in the interlocking device 40 to be released. A release of the connector 6 a can be signaled visually at the charging station 2 .
On the other hand, it is possible that the connector 6 a either remains locked in the interlocking device 40 beyond the charging time and must be released, or that the user wishes to unlock the charging cable 6 during the charging time. In this case the user approaches the charging station 2 and inputs a second release code via the PIN pad 20 . The user has preferably retained the receipt 28 and can thus read from this the first release code previously output and then input it. The release code input is transmitted from the input/output terminal 14 to the microprocessor 12 . The microprocessor 12 stores the previously output first release code and this is compared with the second release code input by the user. In the event of a positive comparison result the microprocessor 12 transmits a release signal to the vehicle 30 , whereupon the charging cable connector 6 a is unlocked from the interlocking device 40 and can be removed.
It is also possible for the first release code not to be generated in the charging station 2 , but received from a control centre 32 . To this end, following completion of the payment process, the charging station 2 can send a request signal to the control centre 32 via the radio communication path 36 . The control centre 32 answers with a first release code, which is received by the communication means 16 in the charging station 2 and can be output via the display 22 .
With the help of the method described, a charging process can be protected from deliberate interruption. A charging time that has been paid for can be guaranteed by the charging station, since a charging cable cannot readily be removed from the vehicle, until the charging time paid for has elapsed or the person entitled to do so has ended the charging process. | Method for securing a charging process of a vehicle ( 30 ) at a charging station ( 2 ), comprising outputting a random or pseudorandom first release code to a user on the charging-station side, releasing the charging current on the charging-station side, receiving a second release code that is input by a user on the charging-station side, comparing the first release code with the second release code on the charging station-side, and interrupting the charging current on the charging-station side in the event of a positive comparison result. | 8 |
BACKGROUND OF THE INVENTION
Field of the Invention
The invention is directed to a method and to an apparatus for the cleaning and/or care of floors and/or floor coverings of all types such as carpets, synthetics, linoleum, parquet, ceramic, ceramic tiles or marble, etc., with a single-disk or multi-disk rotary machine.
Great numbers of devices for cleaning floors and/or floor coverings are known. The overwhelming majority of these are constituted, in terms of design and equipment, only for cleaning textile floor coverings and are not suitable for the cleaning or care of other floor coverings such as synthetic, linoleum, parquet or marble.
DE-U-8 304 300.7 discloses a carpet cleaning device that utilizes the electrostatic charging of the dirt particles. Cleaning at elevated temperature is thus not provided; however, EP-B1-0188475 proposes a cleaning at elevated temperature between 40° and 80° [C.] for carpeted floors. A treatment of other floors at elevated temperature is not provided.
Single-disk machines for the cleaning and care of plastic, wood or stone floors are known that are often fashioned with rotating brushes. Such rotary cleaning machines, however, usually do not comprise any means for applying heat to the surface to be processed. When an old layer of polish that has become unattractive due to dirt or abrasion must be removed from the floor before the application of a new polish layer, then this is usually undertaken with a substantial utilization of chemical cleaning agents, particularly with an ecologically suspect, so-called basic cleaner, a highly alkaline or acidic substrate, as well as employment of hot water. The basic cleaner dissolved in hot water was thereby poured onto the floor or distributed with cleaning rags and the dirty layer was removed after a predetermined time with the assistance of the cleaning machine. An uneconomically high employment of manual labor was thereby required in order to carry out this complicated work that is questionable from the point of view of environmental pollution. The action of warm water thereby also decreases quickly given this type of floor cleaning because the water film applied on the floor represents such a slight heat store that an effective heating of the floor layer to be cleaned is not assured.
DE-A-26 15 501 discloses a carpet cleaning machine. This reference discloses a washer vacuum/compressed air/spray and suction system for wet cleaning of permanently laid materials with which cleaning fluid is pressed onto the material to be cleaned with compressed air via a fan nozzle and is in turn immediately extracted by compulsory vacuum. The compressed air can be heated by an electric heater; likewise, the material can be dried by restricted hot air. A substantial disadvantage of this system is caused by the construction that is extremely involved and complicated in design terms; over and above this, effective employment requires substantial experience. Further, great quantities of cleaning agents are required and the drying time is comparatively long, despite heating.
SUMMARY OF THE INVENTION
The present invention is based on the object of specifying a method and an apparatus that are suitable for universal cleaning and/or care of floors and/or care coverings of all types such as carpets, plastics, linoleum, parquet, ceramic, ceramic tiles or marble, etc., and that avoid the afore-mentioned disadvantages, difficulties and technical limits of known apparatus. In particular, an essentially constant temperature should thus be capable of being set in the region of the working field without requiring a separate heating of the supply of water and/or cleaning agent or care agent. Further such an effective cleaning effect should be capable of being achieved with the method and with the apparatus that a thorough cleaning of floors or floor coverings of all types can be implemented given an extremely economical employment of labor, as well as of cleaning or care agents with less work outlay than hitherto, and while avoiding an employment of chemical, particularly ecologically questionable basic cleaners.
In a method of the species initially cited, this object is inventively achieved in that a hot air stream and/or heated auxiliary medium is employed as heat carrier and activation medium and the hot air stream or, respectively, the heated auxiliary medium proceeds onto the floor surface through the drive plates.
What is surprisingly achieved for the first time with the method is that an essentially constant temperature of the floor or, respectively, floor covering to be handled, is generated and maintained in the region of the work field without a separate heating of the water or, respectively, cleaning or care agent kept on hand being required for this purpose. Such an effective cleaning or care effect is thereby achieved that, for example, even a thorough cleaning of floors of all types given an extremely economical use of labor as well as of cleaning or care agents can be implemented with relatively less work outlay than hitherto, while avoiding an employment of chemical, particularly ecologically questionable basic cleaners. In particular, fatty dirt (approximately 50% of all contaminants contain fat) are dissolved and eliminated substantially faster with the method upon application of controlled heat than with known methods. In view of the great shortage of labor and increasing labor costs, for example in the hospital field, the significant improvement of the cleaning effect which has been demonstrated in trials leads to a noticeable reduction in costs and personnel.
A development of the method provides that the auxiliary medium is heated in steps whereby it is pre-heated in the hot air stream in a first step and is then heated further when passing through the drive plate.
Another development of the method provides that the auxiliary medium is pre-heated upon employment of a heatable collecting dish as a first heating stage.
A further development provides that the auxiliary medium is delivered onto the surface to be treated, passing through the rotational center. An extremely good distribution given simultaneous heating of cleaning or, respectively, care agent as well as floor surface is thereby effected.
Another development provides that the hot air stream emerges against the drive plate and the mat with a comparatively high speed upon formation of a high-energy flow, whereby auxiliary mediums such as water or liquid or, respectively, pasty cleaning or care substrate is delivered through the drive plate onto the floor and is uniformly distributed due to the flow pressure.
A further development of the method provides that the temperature of the surface to be handled is monitored upon employment of a temperature sensor preferably located in the rotational center of the rotor.
A further development provides that the temperature of the surface to be handled is set based on the criterion of a predetermined cleaning or care agenda and/or based on the type of floor covering. The energy expenditure can be set to a comparatively economical degree as a result thereof.
Given optimum cleaning or, respectively, care effect, an extremely economical and effective use of cleaning or care agents as well as of energy and labor are achieved overall.
An apparatus for cleaning and/or care of floors and/or floor coverings of all types comprising a drive unit arranged above a machine housing in a motor housing as well as a rotor driven by said drive unit via a shaft and comprising a drive plate arranged at the underside of the rotor for the implementation of the method of the invention is characterized in that
said apparatus comprises a generator for generating a high-energy hot air stream with a hot air conduit and comprises a hot air discharge nozzle directed downward within the machine housing, whereby the hot air generator is equipped with a temperature selector for a plurality of temperature levels;
in that the drive plate comprises holes or, respectively, clearances; and
in that the exhaust element of the generator is arranged in an axis that is approximately parallel to the axis of the rotor and has its outlet preferably arranged immediately above the drive dish approximately in the center between rotational center and periphery of the drive dish.
Further advantageous developments are described below. Details, features and advantages derive from the following explanation of the exemplary embodiments schematically shown in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a side view of the apparatus;
FIG. 2 shows a plan view onto the perforated drive dish;
FIG. 3 shows a side view of the apparatus, partially in section;
FIG. 3a shows a the upper end of the guide rod in a front view with integrated hand switch;
FIG. 4 shows a view of the underside of the apparatus;
FIG. 5 shows a section through the drive dish along the line of section V--V in FIG. 6;
FIG. 6 shows a plan view onto the drive dish according to FIG. 5;
FIG. 7 shows a view of the fluid pipe for auxiliary medium, shown approximately lifesize;
FIG. 8 shows a view of the apparatus with a heated collecting dish;
FIG. 9 shows a plan view onto a drive dish with and integrated electric heater.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The apparatus shown in FIG. 1 comprises a rotor 1 having a drive unit 5 in a motor housing 25. The rotor 1 is seated on a shaft (not shown) in the machine housing 24 and has a preferably profiled drive dish 2 at its underside together with a co-rotating mat 50 lying therebelow. As may be seen from FIG. 2, the drive dish 2 is fashioned with holes 3 or, respectively, slot-shaped clearances 4 and potentially has its underside fashioned as a brush.
The mat 50 can be differently implemented in conformity with the type of floor covering 49 to be treated; given employment for carpet cleaning, for example, it comprises a covering with cleaning bristles. The mat 50 can be composed of a porous, textile member, for instance of a fleece with diamond points, and the underside thereof carries a structured covering matched to the respective cleaning procedure. Dependent on the type of cleaning, there are extremely different mats 50, which are also referred to as pads. They can be composed of weaves having a more or less hard textile material; they can be air permeable or impermeable as well for cleaning carpets or materials and, for example, can be composed of polyvinyl fibers. Harder weaves for through cleaning are composed of polyester or, respectively, polyethylene (nylon). For roughing-down work or shampooing, brushes having hard bristles are employed. Other pads, which are composed of disk-shaped fleeces, for example of polyester or nylon, can comprise embedded grinding members dependent on hardness. Such pads are provided with different colors for identification dependent on their lower or greater abrasion. Green-colored pads have moderate abrasion. They are usually employed in cleaner procedures; black pads are utilized for thorough cleaning. Pads can also occasionally comprise clearances.
The apparatus comprises a generator 20, which may include an industrial fan and a device for generating heat such as an infrared radiator or a microwave generator, for generating a hot air stream 23 whose temperature can be set adapted to the nature of the floor or, respectively, floor covering 49 to be treated. A favorable cleaning temperature for textile coverings, for example, lies at 40° Celsius and lies at a maximum of 80° Celsius for non-textile floors and/or coverings.
The hot air generator 20 comprises a blow-out element 21 whose outlet 22 is arranged directly above the drive dish 2. The outlet 22 of the blow-out element 21 is located approximately in the middle between the rotational center and the periphery of the drive dish 2.
As a result of this arrangement, the hot air stream 23 and the clean or care substrate delivered together therewith are advantageously applied onto the floor surface 49 to be cleaned passing through the drive dish or, respectively, the brush 2 and/or the pad 50. The industrial fan 20 thereby generates a hot air stream 23 emerging at comparatively high speed, whereby the action of the hot air, for example through pores in the pad 50 toward the floor surface 49 (FIG. 3), results in an advantageous intensification of the cleaning effect. The advantage is that the quantity of heat transported in the hot air stream 23 is brought to bear on the floor covering surface 49 being cleaned or cared for on a short path through the drive dish 2 and the co-rotating pad 50.
As seen in FIG. 3, the inventive cleaning and care apparatus is equipped with a standard undercarriage, for example having two wheels 44, as well as with a guide rod 45, at the preferably heavy machine housing 24. The apparatus comprises a dosing means 38 for cleaning or care agent whose exit opening is arranged above the drive dish 2. The measure that the dosing means 38 comprises a discharge channel arranged in the rotational axis x--x of the shaft of the rotor 1 can thus be utilized. What is thus achieved is that cleaning or care agent emerging through the rotational center is applied onto the surface 49 to be cleaned and is distributed thereon uniformly and extremely economically by the rotating pad 50. Further, a temperature sensor that extends up against the floor covering 49 to be treated is arranged in the rotational axis x--x. This temperature sensor then cooperates with a known control means for the purpose of optimally setting the temperature of the surface 49 to be cleaned based on the criterion of a predetermined cleaning or care agenda and/or on the type of floor covering.
FIG. 3 shows the cleaning machine in a side view and partially in section. This cleaning machine comprises a diecast housing 24 having an undercarriage with two wheels 44 arranged thereat. The guide rod 45 is arranged at the undercarriage and an operating handle 46 having an on/off switch 47 is arranged at the end thereof corresponding to the illustration in FIG. 3a. The guide rod 45 is connected to the machine housing 24 in an articulation 43 in a way capable of being hinged up and down. The apparatus comprises a fluid reservoir 39 that optionally accepts water or a cleaning or, respectively, care substrate as and auxiliary medium. The flexible hose 37 is connected thereto, this conducting the auxiliary medium to a dosing means 38. An exit pipe 40 is connected proceeding from the latter, this having its discharge side fashioned with a pipe coil 42 having discharge nozzles 41 shown in FIG. 7. The illustration also shows the motor housing 25 with the internally disposed motor as well as the rotor 1 with drive dish 2 and shows the pad 50 in an interactive connection with the floor or, respectively, floor covering 49. The stationary machine housing 24 shown in section accepts the hot air generator 20 with connected hot air conduit 29 at its upper side, this hot air conduit 29 discharging into the blow-out element 21 with hot air discharge nozzle 30.
Since the setting of the working temperature plays an extremely important part in the apparatus relative to the floors or, respectively, floor coverings 49 to be treated, it is provided that the hot air generator 20 comprises a plurality of temperature levels and a temperature selector 31. For monitoring the working temperature, a temperature sensor (not shown) that extends down against the floor 49 or, respectively, floor covering to be treated is advantageously arranged in the rotational axis x--x of FIG. 1. This temperature sensor is fashioned such, collaborating with a temperature control means 31 of the hot air generator 20, that a working temperature that has been pre-set is maintained under all working conditions.
FIG. 4 shows the machine housing 24 in a view from below. This is a bell-shaped member downwardly fashioned to form a cavity subdivided by ribs 10, this member being downwardly closed with a preferably thermally insulating cover 11, in a plane y--y of FIG. 3, erected over the ends of the ribs 10. As also proceeds from FIGS. 4 and 7, the discharge pipe 40 equipped with discharge nozzles for auxiliary medium has its end at the discharge side fashioned to form a tube coil forming a heat exchanger and this is arranged in the hot air stream 23 of FIG. 1 below the blow-out element 21 of FIG. 3 composed of the discharge nozzle 30. As a result thereof, the auxiliary medium conducted through the discharge pipe 40 is intensively heated in the hot air stream 23 at a temperature between 250° and 400° Celsius. FIG. 4, moreover, shows the arrangement of the discharge pipe 40 following the dosing means 38 up to its fashioning as pipe coil 42 in the region of the hot air stream 23 under the hot air exit nozzle 30. The wheels of the undercarriage 44 are arranged at a continuation 26 of the machine housing 24.
FIGS. 5 and 6 show the drive dish 2 in section as well as in plan view. At its upper side, this comprises concentric ribs 15 arranged in a plurality of radial spacings increasing from the rotational center to the periphery that intensify the heat transmission from the hot air stream 23 in FIG. 1. These ribs are penetrated by radial ribs 17, upon formation of circular sector-shaped, upwardly open cells 16, whereby each cell 16 comprises clearances 4 for delivered auxiliary agent. As viewed in the direction of the rotatory motion of the drive dish 2, these are arranged adjacent to the front side of each radial rib 17.
FIG. 8 shows a somewhat different design of the apparatus. In this embodiment, the auxiliary medium is heated exclusively by heater stages provided with electric heaters 6 (FIG. 9). A heatable collecting dish 7 is arranged above the drive dish 2 as first heating stage. Auxiliary medium is delivered thereunto with the discharge nozzle 36. The collecting dish 7 comprises exit bores distributed approximately uniformly over its surface and through which the auxiliary medium flows uniformly distributed onto the likewise electrically heatable drive dish 2 that forms the second heating stage. The heated auxiliary medium penetrates therethrough into the pad 50 and proceeds in a predetermined temperature condition onto the surface of the floor or, respectively, floor covering 49 to be cleaned.
In this embodiment, electric heater devices 6 are formed in the drive dish 2, as indicated in a primarily schematic fashion in FIG. 9. The drive dish 2 comprises apertures 3 for the passage of water or other auxiliary medium that--as viewed in the direction of the rotatory motion of the drive dish 2--are arranged neighboring the front side of each radial rib 17. A dog flange 8 with integrated power lead (not shown) that is indicated as a black circle is arranged in the region of the rotational center of the drive dish.
The following advantages are achieved with the method and the apparatus of the invention:
generating an essentially constant temperature at the work field given economical employment of thermal energy;
the separate heating of cleaning and/or care agents, for example wax or wax emulsion, can be eliminated;
as a consequence of an enhanced, extremely efficient cleaning effect, the employment of warm water with cleaning agent solution on a case-by-case basis can be eliminated; likewise, the employment of personnel in the delivery, distribution and processing of the care agent is substantially reduced, a noticeable cost-saving being achieved as a result thereof;
the use of ecologically questionable basic cleaners having a highly alkaline or acidic concentration can be substantially reduced if not entirely eliminated since "gentle" cleaners are employed as a result of the elevated working temperature in the working field.
As a consequence of the high performance capability given reduced employment of personnel, an extremely broad field of employment derives as the area of the employment of the method and of the cleaning machine, such as, for example:
department store areas, particularly meat departments, cheese department, etc., that were hitherto cleaned in a conventional way with scrubbers and pick-ups because these were not accessible to automatic units for reasons of space. The shorter, easier and cost-saving operation is advantageous.
napped floors were hitherto cleaned with single-disk machines and scrubber brushes. Installed articles were thereby contaminated by splashes of water and required further work for after-cleaning. The method and the apparatus of the invention alleviates this situation. Included among further areas of employment are:
warm shampooing given textile coverings that do not shrink at elevated temperature. Enhanced dissolving of dirt and a reduced chemical part due to thermal treatment are advantageous.
Cleaner methods: heat promotes the dissolving of dirt and the absorption of dirt.
Thorough maintenance cleaning (intermediate cleaning) of large areas is possible at low cost.
Streaks, films and striae after cleaning polished surfaces are reduced since usually too much or too little cleaning agent was employed in the hitherto, cold, conventional procedure.
Non-neutral cleaning agents can no longer damage the floor covering to be cleaned as a consequence of an excessively high dosing since weaker cleaning agents and/or lower concentrations of the cleaning agent are required as a result of the heat factor.
Optimum polishing qualities are possible outside the high-speed range, as are repairs of damaged polished surfaces due to the action of heat.
Overall, the possibilities of employment are substantially expanded and the cleaning method is rationalized with the invention, as a result whereof surprisingly beneficial cost-savings can be achieved and service concerns burdened by increasing costs for personnel can work more economically and efficiently.
The inventive measures are not limited to the exemplary embodiments shown in the FIGS. of the drawing. A possible modification of the apparatus of the invention can be comprised therein that a different type of temperature generation or guidance of the hot air stream ensues. Further, the drive dish or dishes can be fashioned in any desirable way and can comprise various hole or, respectively, aperture patterns for the passage of air and/or cleaning or, respectively, care agent and can also comprise various brush profiles. The respective design embodiment is at the discretion of a person skilled in the art in adaptation to specific employments of the apparatus.
As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that we wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of our contribution to the art. | In a method for cleaning and/or care or floors and/or floor coverings of all types such as carpets, plastics, linoleum, parquet, ceramic, ceramic tiles or marble, etc., with a single-disk or multi-disk rotary machine having at least one drive dish, whereby the floor covering is treated with a cleaning and/or care substrate upon application of heat on a case-by-case basis, an especially good and economical operation succeeds in that a stream of hot air and/or heated auxiliary medium is employed as heat carrier and activation medium, and the hot air stream and/or heated auxiliary medium proceeds onto the floor surface through the drive dish. An apparatus suitable for this purpose comprises a drive dish provided with clearances and comprises a hot air generator. The drive dish can be fashioned as a brush at its underside and/or can have an interactive connection to a co-rotating pad. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a National Stage of International patent application PCT/EP2009/065663, filed on Nov. 23, 2009, which claims priority to foreign French patent application No. FR 0807404, filed on Dec. 23, 2008, the disclosures of which are incorporated by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates to a method for determining azimuth and elevation angles of arrival of coherent sources. It is used, for example, in all locating systems in an urban context in which the propagation channel is disturbed by a large number of obstacles such as buildings. Generally, it can be used to locate transmitters, for example a cell phone, in a difficult propagation context, whether it be an urban environment, a semi-urban environment—for example an airport site—, the interior of a building or under snow, in the case of an avalanche. The invention can also be used in medical imaging methods, to locate tumors or sources of epilepsy, the tissues of the human body being the origin of multiple wave paths. It also applies to sounding systems for mining and oil surveys in the seismic domain, in which the aim is to estimate angles of arrival with multiple paths in the complex propagation medium of the earth's crust.
The invention is situated in the technical field of antenna processing which processes the signals from a number of transmitting sources based on a multiple-sensor reception system. More specifically, the invention relates to the field of goniometry which consists in estimating the angles of arrival of the sources.
BACKGROUND
In an electromagnetic context, the sensors are antennas and the radiofrequency sources are propagated according to a polarization that is dependent on the transmitting antenna. In an acoustic context, the sensors are microphones and the sources are sounds.
FIG. 1 shows that an antenna processing system comprises an array 102 of sensors receiving sources with different angles of arrival θ mp . The individual sensors 101 of the array receive the sources E 1 , E 2 with a phase and an amplitude that are dependent in particular on their angles of incidence and on the position of the sensors. The angles of incidence are parameterized in one dimension (1D) by the azimuth θ m and in two dimensions (2D) by the azimuth θ m and the elevation Δ m .
According to FIG. 2 , a 1D goniometry is defined by techniques which estimate only the azimuth by assuming that the waves of the sources are propagated in the plane 201 of the array of sensors. When the goniometry technique jointly estimates the azimuth and elevation of a source, it is an issue of 2D goniometry.
The aim of the antenna processing techniques is notably to exploit the spatial diversity generated by the multiple-antenna reception of the incidence signals, in other words, to use the position of the antennas of the array to better use the differences in incidence and distance of the sources.
FIG. 3 illustrates an application to goniometry in the presence of multiple paths. The m-th source 301 is propagated along P paths 311 , 312 , 313 of incidences θ mp (1≦p≦P) which are provoked by P−1 obstacles 320 in the radiofrequency environment. The problem dealt with in the method according to the invention is, notably, to perform a 2D goniometry for coherent paths in which the propagation time deviation between the direct path and a secondary path is very low.
One known method for doing the goniometry is the MUSIC algorithm [1]. However, this algorithm does not make it possible to estimate the incidences of the sources in the presence of coherent paths.
The algorithms that make it possible to process the case of coherent sources are the maximum likelihood algorithms [2][3] which are applicable to arrays of sensors with any geometry. However, these techniques require the calculation of a multidimensional criteria of which the number of dimensions depends on the number of paths and on the number of incidence parameters for each path. More particularly, in the presence of K paths, the criterion has 2K dimensions for a 2D goniometry in order to jointly estimate all the incidences ( Θ 1 , . . . , Θ K ). It should be noted that, even in the presence of a number K′ of coherent paths that is less than the total number K of paths, the calculation of the maximum likelihood criterion still has 2K dimensions. In order to reduce the number of dimensions of the criterion to 2K′, one alternative is to apply the coherent MUSIC method [4]. However, the coherent MUSIC algorithm [4] requires a high number of sensors and very significant computation resources.
Another alternative for reducing the computation cost is to implement spatial smoothing or forward-backward techniques [5][6], these techniques requiring particular array geometries. In practice, spatial smoothing is applicable when the array is broken down into subarrays having the same geometry (e.g.: evenly-spaced linear array or array on a regular 2D grid). The forward-backward algorithm requires an array with a center of symmetry. These techniques are highly restrictive in terms of geometry of the array of sensors, especially for a 2D goniometry, in which the constraint of symmetry or of translated identical subarrays is difficult to satisfy.
For 1D goniometry, spatial smoothing techniques have been considered on any arrays [6][7]. For this, the array of sensors is interpolated according to the goniometry adapted to spatial smoothing (or forward-backward). In [6] the interpolation technique addresses only a single angular segment and in [7] the algorithm is adapted to the cases of a number of angular segments for the interpolation. However, this kind of technique is difficult to adapt to the case of 2D goniometry.
SUMMARY OF THE INVENTION
One aim of the invention is to propose a method for determining, from an array of sensors, the direction of arrival in azimuth and elevation of coherent signals with a reduced computation cost and by limiting as far as possible the geometrical constraints to be imposed on the array of sensors. To this end, the subject of the invention is a method for jointly determining the azimuth angle θ and the elevation angle Δ of the wave vectors of P waves in a system comprising an array of sensors, a number of waves out of the P waves being propagated along coherent or substantially coherent paths between a source and said sensors, the method being characterized in that it comprises at least the following steps:
selecting a subset of sensors from said sensors to form a linear subarray of sensors;
applying, to the signals from the chosen subarray, an algorithm according to a single dimension to decorrelate the sources of the P waves;
determining a first component w of said wave vectors by applying, to the signals observed on the sensors of the chosen subarray, a goniometry algorithm according to the single dimension w;
determining a second component u of said wave vectors by applying a goniometry algorithm according to the single dimension u to the signals from the entire array of sensors;
determining θ and Δ from w and u.
The method according to the invention makes it possible to reduce the complexity of a two-dimensional goniometry problem by dividing it into two phases with a single dimension: a first phase for estimating a projection value w of the wave vector, then a phase for estimating a value of the other component u of the wave vector.
According to one implementation of the method according to the invention,
the sensors forming the subarray are chosen such that at least a portion of the subarray is unchanging by translation;
a spatial smoothing algorithm is applied to decorrelate the sources of the P waves.
The expression “unchanging by translation” should be understood to mean that there is at least one subset of the subarray whose sensors are arranged as if they were the result of a translation of another subset of sensors of said subarray.
According to one implementation of the method according to the invention,
the sensors forming the subarray are chosen such that at least a portion of the subarray includes a center of symmetry;
a forward-backward algorithm is applied to decorrelate the sources of the P waves.
The expression “center of symmetry of the subarray” should be understood to mean that, for each sensor, there is a sensor placed symmetrically relative to said center.
According to one implementation of the method according to the invention, the determined first component w of the wave vectors is the projection, on the axis formed by the linear subarray, of the projection of the wave vectors on the plane formed by the array of sensors. In other words, for each path p, w p =cos(θ p −α)·cos(Δ p ), α being the azimuth angle according to which the axis formed by the linear subarray is oriented.
According to one implementation of the method according to the invention, the method includes at least the following steps:
calculating the covariance matrix R x on the entire array of sensors;
extracting from R x , the covariance matrix R x ′ corresponding to the chosen linear subarray;
applying a source decorrelation algorithm to R x ′;
estimating, for each path p, the values of the first component w p =cos(θ p −α)·cos(Δ p ) by applying a 1D goniometry algorithm to the decorrelated matrix R x ′, α being the azimuth orientation angle of the axis formed by the linear subarray;
estimating the values of the second component u p =cos(θ p )·cos(Δ p ), for each path p, by applying a 1D goniometry algorithm to the matrix R x ;
determining, from the values of the pairs (w p , u p ), the values of the azimuth-elevation pairs (θ p , Δ p ).
According to one implementation of the method according to the invention, the goniometry algorithm used to determine the first component w of each wave vector P is the MUSIC algorithm, the criterion J MUSIC to be minimized to determine said component w being equal to
J MUSIC ( w ) = a l ( w ) H Π b l a l ( w ) a l ( w ) H a l ( w ) ,
in which Π b l is the noise projector extracted from the decorrelated covariance matrix R x ′ corresponding to the chosen linear subarray, and a(w) l represents the response of the chosen subarray to the incident waves P.
According to one implementation of the method according to the invention, the goniometry algorithm used to determine the second component u is the coherent MUSIC algorithm in a single dimension, the criterion to be minimized being:
J coherent MUSIC ( Θ _ ) = det ( D ( Θ _ ) H Π b D ( Θ _ ) ) det ( D ( Θ _ ) H D ( Θ _ ) )
in which Θ ={f 1 (u 1 ) . . . f K max (u K max )}, with
f p ( u ) = f ( u , w p - u cos ( α ) sin ( α ) ) ,
α being the azimuth orientation angle of the axis formed by the linear subarray, D( Θ ) being a vector equal to [a( Θ 1 ) . . . a( Θ Kmax )], a( Θ i ) being the response of the array of sensors to the path of index i, K max being the maximum number of coherent paths.
According to one implementation of the method according to the invention, the goniometry algorithm used to determine the second component is the maximum likelihood algorithm.
According to one implementation of the method according to the invention, the array is disturbed by mutual coupling of known matrix Z, and the method includes a step for eliminating the coupling executed prior to the steps for estimating the values of the components w and u, said step for eliminating the coupling determining a covariance matrix that is cleaned of noise by applying the following processing to the covariance matrix: Z −1 (R x −σ 2 |)Z −1H , σ 2 being the estimated noise level.
According to one implementation of the method according to the invention, the determination of the pairs of values (θ p , Δ p ) from the values of pairs (w p , u p ) is performed as follows:
{ θ p = angle ( u p + j v p ) Δ p = cos - 1 ( u p + j v p )
in which
v
p
=
w
p
-
u
p
cos
(
α
)
sin
(
α
)
.
BRIEF DESCRIPTION OF THE DRAWINGS
Other characteristics will emerge from reading the following detailed description given as a nonlimiting example and in light of the appended drawings which represent:
FIG. 1 , an example of signals transmitted by a transmitter and being propagated to an array of sensors,
FIG. 2 , the representation of the incidence of a source on a plane of sensors,
FIG. 3 , an illustration of the propagation of signals by multiple paths,
FIG. 4 , an example of arrays of sensors of position (x n ,y n ),
FIG. 5 , an example of an array of sensors consisting of two subarrays that are unchanging by translation,
FIG. 6 , an example of an array of sensors consisting of two subarrays making it possible to decorrelate two paths that are coherent in azimuth and elevation,
FIG. 7 , a linear array of sensors in which the spatial smoothing makes it possible to decorrelate two paths that are coherent in azimuth,
FIG. 8 , an array of sensors having a center of symmetry at O,
FIG. 9 , two linear arrays with five sensors, making it possible to decorrelate two paths that are coherent in azimuth for, respectively, spatial smoothing and forward-backward,
FIG. 10 , a first example of an array of sensors containing a linear subarray of sensors and compatible with the method according to the invention,
FIG. 11 , a second example of an array of sensors containing a linear subarray of sensors and compatible with the method according to the invention.
DETAILED DESCRIPTION
Before detailing an exemplary implementation of the method according to the invention, some reminders concerning the modeling of the output signal from an array of sensors are given.
With M sources in which the m-th source contains P m multiple paths, the output signal from the array of sensors is written as follows:
x ( t ) = [ x 1 ( t ) ⋮ x N ( t ) ] = ∑ m = 1 M ∑ p = 1 P m ρ mp a ( Θ _ mp ) s m ( t - τ mp ) + n ( t ) . ( 1 )
in which x n (t) is the signal at the output of the n-th sensor, N the number of sensors, n(t) is the additive noise, a( Θ ) is the response of the array of sensors to a source of direction Θ =(θ, Δ), θ is the azimuth, Δ the elevation and ρ mp , θ mp , τ mp are respectively the attenuation, the direction and the delay of the p-th paths of the m-th source. The vector a( Θ ) which is also called directing vector depends on the positions (x n , y n ) of the sensors 401 , 402 , 403 , 404 , 405 (see FIG. 4 ) and is written
a ( Θ _ ) = Z [ a 1 ( Θ _ ) ⋮ a N ( Θ _ ) ] with { a n ( Θ _ ) = exp ( j 2 π λ ( x n u + y n v ) ) u = cos ( θ ) cos ( Δ ) v = sin ( θ ) cos ( Δ ) . ( 2 )
in which Z is the coupling matrix, λ is the wavelength and (u,v) are the coordinates of the wave vector in the plane of the antenna.
With coherent paths in which the delays of the paths satisfy τ m1 = . . . =τ mPm, the signal model of the equation (1) becomes
x ( t ) = ∑ m = 1 M a ( Θ _ m , ρ m , P m ) s m ( t ) + n ( t )
with
a ( Θ _ m , ρ m , P m ) = ∑ p = 1 P m ρ mp a ( Θ _ mp ) . ( 3 )
in which a( Θ m , ρ m , P m ) is the response of the array of sensors to the m-th source, Θ m =[ Θ m1 . . . Θ mP m ] T and ρ m =[ρ m1 . . . ρ mP m ] T . The directing vector of the source is no longer a( Θ m1 ) but a composite directing vector a( Θ m ,ρ m ,P m ) dependant on a greater number of parameters.
More generally, with K groups of coherent paths, the signal is written:
x
(
t
)
=
∑
k
=
1
K
a
(
Θ
_
k
,
ρ
k
,
K
k
)
s
k
(
t
)
+
n
(
t
)
in
which
K
max
=
max
k
{
K
k
}
.
(
4
)
To enable the reader to better understand the method according to the invention, the processing of the coherent sources in azimuth and elevation in the state of the art is explained hereinbelow.
A first coherent MUSIC algorithm [4] is first described. The MUSIC algorithm [1] is a high-resolution method based on the breakdown into specific elements of the covariance matrix R x =E[x(t) x(t) H ] of the multiple-sensor signal x(t), in which E[.] is the mathematical expectation. The expression of the matrix R X is as follows according to (4):
R
x
=
AR
s
A
H
+
σ
2
I
N
with
{
R
s
=
E
[
s
(
t
)
s
(
t
)
H
]
E
[
n
(
t
)
n
(
t
)
H
]
=
σ
2
I
N
A
=
[
a
(
Θ
_
1
,
ρ
1
,
K
1
)
…
a
(
Θ
_
k
,
ρ
k
,
K
k
)
]
s
(
t
)
=
[
s
1
(
t
)
…
s
K
(
t
)
]
T
.
(
5
)
With K groups of coherent paths, the rank of the matrix R x is K. In these conditions, the K specific vectors e k (1≦k≦K) associated with the K highest specific values λ k of R x satisfy
e
k
=
∑
i
=
1
K
α
ik
a
(
Θ
_
i
,
ρ
i
,
K
i
)
for
(
1
≤
k
≤
K
)
.
(
6
)
The N-K specific vectors e i (K+1≦l≦N) associated with the lowest specific values of R x are orthogonal to the vectors e k (1≦k≦K) of the expression (6) and define the noise space. Since the vectors e i and e k are orthogonal, the directing vectors a( Θ i , ρ i , K i ) are orthogonal to the noise vectors e i . In these conditions, the K minima ( Θ k , ρ k ,K k ) of the following MUSIC criterion
J MUSIC ( Θ _ , ρ ) = a ( Θ _ , ρ , K max ) H Π b a ( Θ _ , ρ , K max ) a ( Θ _ , ρ , K max ) H a ( Θ _ , ρ , K max )
with Π b = ∑ i = K + 1 N e i e i H . ( 7 )
make it possible to give the directions Θ k of each path. However, the cost of calculating the criterion of the equation (7) is very high because it depends on the incidence of K max coherent paths and their relative amplitudes: ( Θ , ρ).
The coherent MUSIC method described in [4] is designed to reduce the number of parameters for searching for the MUSIC criterion. For this, the vector a( Θ m , ρ m , P m ) of equation (3) is rewritten as follows:
a
(
Θ
_
,
ρ
,
K
max
)
=
D
(
Θ
_
)
ρ
with
{
D
(
Θ
_
)
=
[
a
(
Θ
_
1
)
…
a
(
Θ
_
K
max
)
]
ρ
=
[
ρ
1
…
ρ
K
max
]
T
Θ
_
=
{
Θ
_
1
…
Θ
_
K
max
}
.
(
8
)
In these conditions, the criterion of equation (7) is reduced to the following expression:
J coherent MUSIC ( Θ _ ) = det ( D ( Θ _ ) H Π b D ( Θ _ ) ) det ( D ( Θ _ ) H D ( Θ _ ) ) . ( 9 )
in which det(M) is the determinant of the matrix M. The number of dimensions of the criterion is then reduced to 2K max parameters of Θ in which K max is the maximum number of coherent paths. Consequently, the K minima of the criterion J MUSIC-Coherent ( Θ ) gives the directions Θ k ={ Θ k1 . . . Θ kK max } of the paths of each group of coherent paths for 1≦k≦K. Thus, with K max =2 coherent paths, the coherent MUSIC criterion still has four dimensions for an azimuth-elevation goniometry. More generally, the coherent MUSIC method entails calculating a criterion (9) having 2 K max dimensions. However, the method makes no assumption as to the geometry of the array because it entails no constraint on the expression of the directing vector a( Θ ).
Alternative methods that are also known for processing coherent sources are the spatial smoothing [5][6] and forward-backward [5] techniques. These methods make it possible to decorrelate the sources by performing a simple preprocessing on the covariance matrix of the received signals. It is then possible to apply a goniometry algorithm such as MUSIC to the new covariance matrix. These techniques derive from the field of spectral analysis whose objective is to model the frequency spectrum of a signal.
The spatial smoothing techniques [5][6] are applicable to an array of sensors consisting of subarrays 501 , 502 that are unchanging by translation as illustrated in FIG. 5 . With P paths (coherent or not), the expression (1) of the observation vector can be rewritten
x ( t ) = ∑ p = 1 P ρ p a ( Θ _ p ) s p ( t ) + n ( t ) = As ( t ) + n ( t ) ( 10 )
with A=[a( Θ 1 ) . . . a( Θ P )].
The expression of the signal received on the i-th subarray is then written:
x i ( t ) = P i x ( t ) = ∑ p = 1 P ρ p a i ( Θ _ p ) s p ( t ) + n ( t ) = A i s ( t ) + n ( t ) ( 11 )
in which A i =[a i ( Θ 1 ) . . . a i ( Θ P )], P i being a matrix consisting of 0 and 1 making it possible to select the signal of the i-th subarray for which the directing vector a i ( Θ ) satisfies the following relationship:
a i ( Θ )= P i a ( Θ )=α i ( Θ ) a 1 ( Θ ) (12)
Remembering that the incidence Θ =(θ,Δ) depends on the two parameters θ and Δ.
According to (11)(12), the mixing matrix A i of the i-th subarray satisfies
A i =P i A=A 1 Φ i with Φ i =diag{α i ( Θ 1 ) . . . α i ( Θ P )} (13)
According to (11)(13) the covariance matrix R x i =E[x(t) i x(t) iH ] has the following expression:
R x i =A 1 Φ i R s Φ i *A 1H +σ 2 I N in which R s =E[s ( t ) s ( t ) H ] (14)
Consequently, an alternative to the spatial smoothing techniques consists in applying a MUSIC-type algorithm to the following covariance matrix:
R x SM ∑ i = 1 I R x i = ∑ i = 1 I P i R x ( P i ) H ( 15 )
in which R x =E[x(t) x(t) H ]. The aim of this procedure is to obtain a matrix R x SM that has a rank higher than the R x i without destroying the structure of the signal space generated by A 1 . In practice, this technique makes it possible to decorrelate a maximum of I coherent paths because
R x SM = A 1 R s SM A 1 H + σ 2 I N ′ in which
R s SM = ∑ i = 1 I Φ i R s Φ i * ( 16 )
and thus,
rank
{
R
s
}
≤
rank
{
R
s
SM
}
≤
min
(
rank
{
R
s
}
/
,
∑
m
=
1
M
P
m
)
.
The forward-backward [5] smoothing technique requires an array of sensors that has a center of symmetry at O as indicated in FIG. 8 . In these conditions, the directing vector has the following structure
a ( Θ _ ) = β ( Θ _ ) [ b ( Θ _ ) b ( Θ _ ) * ] ( 17 )
in which, according to FIG. 8 , b(Θ) is the directing vector of the subarray of coordinates (x n −x 0 ,y n −y 0 ) and b(Θ)* is the directing vector of the subarray of coordinates (−x n −x 0 ,−y n −y 0 ), bearing in mind that (x 0 , y 0 ) are the coordinates of the center of symmetry O. Consequently, the directing vector of the expression (17) satisfies the following relationship:
Π a ( Θ )*=β( Θ )* a ( Θ ) (18)
in which Π is a permutation matrix consisting of 0 and 1. The forward-backward smoothing technique consists in applying a goniometry algorithm such as MUSIC to the following covariance matrix
R x FB =R x +ΠR x *Π T (19)
bearing in mind that
R x FB =AR s FB A H +σ 2 I N in which R s FB =R s +Φ FB R s Φ FB * (20)
The technique makes it possible to decorrelate two coherent paths because
rank { R s } ≤ rank { R s SM } ≤ min ( 2 rank { R s } , ∑ m = 1 M P m )
with
Φ FB =diag{β( Θ 1 ) . . . β( Θ P )} (21)
The spatial smoothing and forward-backward techniques can be combined to increase the capacity for decorrelation into number of paths. These smoothing techniques make it possible to process the coherent sources with a computation power that is very similar to the application of a single goniometry algorithm such as MUSIC.
When the array of sensors is disturbed by mutual coupling in which the directing vector is written
a ( Θ )= Z ( Θ ) (22)
and in which the directing vector ( Θ ) satisfies one of the properties of the equations (12)(18), the spatial smoothing techniques are applicable [7]. The mixing matrix A of the equation (10) is then written
A=Z with =[ ( Θ 1 ) . . . ( Θ P )] (23)
Consequently, the covariance matrix R x =E[x(t) x(t) H ] is written as follows:
R x =Z ( R s H ) Z H +σ 2 I N (24)
Bearing in mind that i =P i = 1 Φ i (where that Π *= Φ FB ), the following steps make it possible to apply a spatial smoothing or forward-backward technique in the presence of mutual coupling:
Step No. L.1: Break down the covariance matrix R x =E[x(t) x(t) H ] into specific elements such that:
R x =E s Λ s E s H +E b Λ b E b H (25)
in which E s and E b are the matrices of the specific vectors respectively associated with the signal space and the noise space according to MUSIC 0 and in which Λ s and Λ b are diagonal matrices respectively consisting of the specific values of the signal space and of the specific values of the noise space.
Step No. L.2: Extract the non-noise-affected covariance matrix Z( R s H )Z H by performing:
R y = R x - trace ( Λ b ) N - K I N = Z ( A ⋒ R s A ⋒ H ) Z H
in which K is the dimension of the signal space such that K≦P.
Step No. L.3 (Spatial smoothing): Apply the MUSIC algorithm to the following covariance matrix R x SM :
R x SM = ∑ i = 1 I P i ( Z - 1 R y ( Z - 1 ) H ) ( P i ) H
Step No. L.3 (Forward-Backward): Apply the MUSIC algorithm to the following covariance matrix R x FB :
R x FB =( Z −1 R y ( Z −1 ) H )+Π( Z −1 R y ( Z −1 ) H )*Π T
If the directing vector array ( Θ ) permits, the two smoothing techniques of steps No. L.3 can be combined.
The spatial smoothing techniques are applicable with mutual coupling. However, this imposes very strong constraints on the geometry of the individual array which have the drawback of requiring a very large number of sensors. In the following example, we will evaluate the minimum number of sensors to process the case of two sources coherent in azimuth-elevation. For this, it is necessary for:
Constraint C1: The number of sensors of each subarray to be at least equal to N i =4. In practice, because of ambiguities, an array of N sensors makes it possible at most to estimate the direction of arrival of N/2 sources.
Constraint C2: The number of subarrays to be at least equal to 2.
Constraint C3: The subarrays to be planar (not linear) in order to be able to perform an azimuth-elevation goniometry.
FIG. 6 shows that an array consisting of two subarrays 601 , 602 of four sensors contains at least seven sensors. This array also has the drawback of being weakly open (or has little spatial bulk) because the subarrays with four sensors must be unambiguous. Since the subarrays consist of four sensors, this ambiguity constraint requires a spacing between sensors less than λ/2. In practice, the more open a array is, the more accurate the estimation of the angles of arrival is with a better robustness to calibration errors. For the case where the desire is to perform an azimuth goniometry only, the constraint C3 no longer applies and the array making it possible to perform a goniometry on two coherent sources consisting of two subarrays of four sensors is an evenly-spaced linear array with five sensors. Each subarray is then an evenly-spaced linear array with four sensors. FIG. 7 shows that the linear subarray 701 which allows for the azimuth goniometry of two coherent paths has the following differences compared to the array 702 which makes it possible to do so in azimuth and elevation: on the one hand, it consists of fewer sensors: five instead of seven, and on the other hand, it has a greater bulk: 4 d instead of 3 d, bearing in mind that d is a distance less than λ/2, λ being the wavelength of the transmitted signals.
For the forward-backward technique requiring an array with a center of symmetry as illustrated in FIG. 8 , it is possible to note that, for the spatial smoothing: the decorrelation of two coherent paths for an azimuth-elevation goniometry requires an array of sensors having more sensors and less aperture than the array making it possible to perform an azimuth goniometry only. For an azimuth goniometry, a linear array, not necessarily evenly-spaced, is sufficient.
FIG. 9 shows that the forward-backward technique makes it possible, compared to the spatial smoothing technique, to perform an unambiguous goniometry on two coherent paths with an array 901 having a greater aperture (10 d instead of 4 d for an array 902 used for spatial smoothing). The forward-backward technique has the advantage of not imposing any geometry constraint on half the array. The other half of the array is symmetrical to the 1st half.
The method according to the invention described combines the coherent MUSIC method with a forward-backward technique and/or a spatial smoothing technique. Given the advantages and drawbacks of the smoothing techniques and of the coherent MUSIC algorithm described above, the method envisages using an array of sensors containing a linear subarray on which a spatial smoothing and/or forward-backward technique can be envisaged. FIG. 10 shows such an array 1001 with a linear subarray 1002 having an orientation α relative to the x axis. More specifically, the method according to the invention can use the array 1101 of FIG. 11 in which the angle α=90° and the linear subarray 1102 consists of 3 evenly-spaced sensors on which a forward-backward technique can be applied.
The coordinates (x n l , y n l ) of the n-th sensor of the linear subarray then have the following expression:
{ x n l = ρ n cos ( α ) y n l = ρ n sin ( α )
for 1 ≤ n ≤ N l ( 26 )
in which N l is the number of sensors of the linear subarray. In the absence of coupling and according to (2), the directing vector a l ( Θ ) associated with the linear subarray is written
a
l
(
Θ
_
)
=
[
a
1
l
(
Θ
_
)
⋮
a
N
l
l
(
Θ
_
)
]
with
a
n
l
(
Θ
_
)
=
exp
(
j2π
ρ
n
λ
cos
(
θ
-
α
)
cos
(
Δ
)
)
(
27
)
The vector a l ( Θ ) then depends on a single parameter w=cos(θ−α)cos(Δ) as follows:
a l ( Θ _ ) = a l ( w ) = [ z ρ 1 ⋮ z ρ N l ] with z = exp ( j 2 π λ w ) ( 28 )
x l (t) is used to denote the signal at the output of the linear subarray and P roj the matrix consisting of 0 and 1 that can be used to extract the signals from the linear subarray such that
x l ( t )= P roj x ( t ) (29)
in which x(t) is the signal observed on all the sensors of the array. The relationship between the variable w=cos(θ−α)cos(Δ) and the coordinates of the wave vector (u,v) of the equation (2) is as follows:
w=u cos(α)+ν sin(α) (30)
Knowing w, the incidence Θ becomes a 1D function dependent on the parameter u such that:
Θ _ ( u ) = ( θ , Δ ) = f ( u , v ) = f ( u , w - u cos ( α ) sin ( α ) ) ( 31 )
in which the function f(u,v) is given by the expression (2). When α=0, the vector of parameter Θ cannot depend on the variable u: In this case, the incidence Θ depends on the variable v with the function Θ (v)=f((w−ν sin(α))/cos(α),ν). In the interests of simplicity in the description of the method and without compromising generality, it will be assumed that it is still possible to write Θ as a function of u. Consequently,
Θ
_
p
=
f
p
(
u
p
)
with
f
p
(
u
)
=
f
(
u
,
w
p
-
u
cos
(
α
)
sin
(
α
)
)
(
32
)
With P paths of which at least one group of K max are coherent, the example described of the method according to the invention contains at least the following steps:
Step A: Application of a spatial smoothing and/or forward-backward technique to the observation vector x l (t) of the linear array. After a 1D goniometry according to the variable w, the incidence parameters w p =cos(θ p −α)cos(Δ p ) are obtained for (1≦p≦P). The 1D MUSIC criterion has the following expression:
J MUSIC ( w ) = a l ( w ) H Π b l a l ( w ) a l ( w ) H a l ( w ) ( 33 )
in which Π b l is the noise projector extracted from the smoothed covariance matrix.
Step B: With K max ≦P coherent paths, application of the coherent MUSIC method described above with the variable Θ ={ Θ 1 . . . Θ K max } which is the following function of the variable u ={u 1 . . . u K max }
Θ ={ f 1 ( u 1 ) . . . f K max ( u K max )} (34)
in which the coherent MUSIC criterion J coherent MUSIC is a function of the variable u having K max dimensions.
Step C: from K (K being the rank of the covariance matrix R x ) solutions u k minimizing the function J coherent MUSIC ( u ) it is possible to extract the P pairs of incidences (w p ,u p ) for (1≦p≦P) and deduce the incidences (θ p ,Δ p ) therefrom by performing
{
θ
p
=
angle
(
u
p
+
j
v
p
)
Δ
p
=
cos
-
1
(
u
p
+
jv
p
)
in
which
v
p
=
w
p
-
u
p
cos
(
α
)
sin
(
α
)
(
35
)
The preceding steps show that the calculation of a criterion with 2K max dimensions for the coherent MUSIC algorithm alone in 2D has been replaced by the calculation of a MUSIC criterion with one dimension according to the parameter w and the cost of calculation of the 1D coherent MUSIC criterion with the variable u having K max dimensions. The gain in computation power is then equal to
Gain = nb ( 2 K max - 1 ) 1 + nb ( K max - 1 ) ≈ nb K max ( 36 )
in which nb is the number of points of the meshes of the criteria (MUSIC or coherent MUSIC) according to the variables u and v of the components of the wave vector. In the general case nb is large while being proportional to the size of the array (nb>50).
It will be assumed that u k is a solution parameter vector for coherent MUSIC when
J coherent MUSIC ( u k )<η( K max ) (37)
in which η(K max ) is a threshold between 0 and 1 because the criterion J coherent MUSIC ( u ) is normalized. When the number K′ of solutions u k is less than the rank K of the covariance matrix R x , it can be deduced therefrom that the number of coherent paths is greater than K max . For the case where K′<K max the coherent MUSIC algorithm will be applied with K max =K max +1. Consequently, the method makes it possible to jointly estimate the incidences of the paths with the number of coherent paths.
Similarly, it will be assumed that w p is a solution parameter of the 1D goniometry of step A when
J MUSIC ( w p )<η (38)
In which η is a threshold between 0 and 1 because the criterion J MUSIC (w) is normalized.
The method envisages treating the case in which at least two coherent paths satisfy w i =w j with u i ≠u j . This problem can be detected when:
the rank of the smoothed covariance matrix remains equal to that of the covariance matrix Rx;
the MUSIC method does not work on the non-smoothed covariance matrix Rx.
By assuming that there are K max coherent paths and that 1D MUSIC w gives P′<K max coherent path solutions, the method consists in complementing the incomplete list of P′ elements {w p } with K max , −P′ estimation of the initial list of {w p }. More specifically, with K max =2 coherent paths and P′=1 parameter w 1 detected, it is essential to apply the coherent MUSIC method of step B with w 1 =w 1 and w 2 =w 1 or the set of parameters {w 1 , w 1 }. In the case where K max =3 coherent paths and P′=2, there are two configurations to which the 1D coherent MUSIC step B must be applied: {w 1 , w 2 , w 2 } and {w 1 , w 1 , w 2 }. Consequently, when P′<K max the step B of the method can be applied several times. There are thus L sets of following incidences w p to which the step B of the method must be applied:
Ω
i
=
Ψ
⋃
X
i
for
(
1
≤
i
≤
L
)
with
{
Ψ
=
{
w
p
for
1
≤
p
≤
P
′
}
X
i
⋐
Ψ
and
cardinal
(
X
i
)
=
K
max
-
P
′
(
39
)
The number L and the sets Ω i can be determined by a conventional arithmetical process.
The following steps of the method make it possible to estimate the direction of arrival of P paths in azimuth-elevation bearing in mind that there is at least one group of K max coherent paths and that the array is disturbed by mutual coupling of known matrix Z.
Step No. 1: Breakdown the covariance matrix R x =E[x(t) x(t) H ] into specific elements such that
R x =EΛE H
in which E is the matrix with the specific vectors and Λ is a diagonal matrix consisting of the specific values.
Step No. 2: From the specific values of the matrix Λ, determination of the number K of dominant specific values giving the rank of R x .
Step No. 3: Following breakdown of the matrix R x
R
x
=
E
s
Λ
s
E
s
H
+
E
b
Λ
b
E
b
H
with
{
E
=
[
E
s
E
b
]
Λ
=
[
Λ
s
0
0
Λ
b
]
In which E s and E b are the matrices of the specific vectors respectively associated with the signal space bearing in mind that dim (E s )=N×K and in which Λ s and Λ b are diagonal matrices respectively consisting of the specific values of the signal space and the specific values of the noise space.
Step No 4: Extraction of the non-noise-affected and coupling-free covariance matrix by performing
R
y
=
Z
-
1
(
R
x
-
trace
(
Λ
b
)
N
-
K
I
N
)
Z
-
1
H
In which K is the dimension of the signal space such that K≦P.
Step No. 5: Calculation of the noise projector of the matrix R y in the following way:
Π b =I N −Z −1 ( E s ( E s H Z −1H Z −1 E s ) −1 E s H ) Z −1H
Step No. 6: Application of the 2D MUSIC algorithm with the criterion J MUSIC ( Θ )=( ( Θ ) H Π b H ( Θ ))/( ( Θ ) H ( Θ )) with the vector ( Θ ) of the equation (22). Estimation of P 0 ≦K incidences Θ p (1≦p≦P 0 ) satisfying J MUSIC ( Θ p )<η(1). Formation of the set Θ ={ Θ 1 . . . Θ P0 } of the non-coherent paths. If P 0 <K, go to step No. 7.
Step No. 7: Calculation of the covariance matrix of the linear array by performing R x l =P roj R x P roj H bearing in mind that x l (t)=P roj x(t).
Step No. 8: Application of one (or both) of the smoothing techniques to the matrix R x l of the linear array by performing either
R ~ x = ∑ i = 1 I P i R x l ( P i ) H
for smoothing or {tilde over (R)} x =R x l +Π(R x l )*Π T for the forward-backward.
Step No. 9: From a breakdown into specific elements of the matrix {tilde over (R)} x , estimation of the rank P of the signal space and of the noise projector Π b l =E b E b H (step of the MUSIC algorithm reviewed in steps 1 to 3 of this method for the matrix R x ).
Step No. 10: Application of the 1D MUSIC algorithm with the criterion J MUSIC (w)=(a l (w) H Π b l a l (w))/(a l (w) H a l (w)) with the vector a l (w) of the equation (28). Estimation of P incidences w p (1≦p≦P) satisfying J MUSIC (w p )<η.
Step No. 11: Formation of the set Ψ of the incidences w p associated with a coherent path such that Ψ={w p ≠cos(θ i −α)cos(Δ i ) in which Θ i ={θ i , Δ i }∈ Θ }
Step No. 12: If P>K, then K max =cardinal(Ψ) and L=1 with Ω 1 =Ψ. Go to step No. 14.
Step No. 13: If P≦K, then K max =K+1 and formation of the L sets of parameters Ω i of the equation (39) with P′=cardinal(Ψ).
Step No. 14: i=1
Step No. 15: Application of the 1D coherent MUSIC steps B and C described on page 18 with Θ =f( u )={f 1 (u 1 ) . . . f K max (u K max )}, bearing in mind that f p (u)=f(u,(w p −u cos(α))/sin(α)) in which w p ∈Ω i . Obtaining of K i incidences Θ k for (1≦k≦K i ).
Step No. 16: For k ranging from 1 to K i if Θ k ∉ Θ then Θ = Θ ∪{ Θ k }
Step No. 17: i=i+1. If i≦L then return to step No. 14.
One advantage of the method according to the invention is that the minimum number of sensors for estimating the direction of arrival of K coherent paths in 2D is lower than with the methods of the prior art, which require a number of sensors greater than 2(K+1), the method according to the invention requiring only a number of sensors greater than K.
Another advantage of the method according to the invention is that it makes it possible to estimate directions of arrival of the paths in 2D with larger arrays, which enhances the accuracy of the estimation.
BIBLIOGRAPHY
[1] R O. SCHMIDT, Multiple emitter location and signal parameter estimation , in Proc of the RADC Spectrum Estimation Workshop, Griffiths Air Force Base, New York, 1979, pp. 243-258.
[2] P. Larzabal Application du Maximum de vraisemblance au traitement d'antenne : radio-goniométrie et poursuite de cibles. PhD Thesis, Université de Paris-sud, Orsay, FR, June 1992
[3] B. Ottersten, M. Viberg, P. Stoica and A. Nehorai, Exact and large sample maximum likelihood techniques for parameter estimation and detection in array processing . In S. Haykin, J. Litva and T J. Shephers editors, Radar Array Processing, chapter 4, pages 99-151. Springer-Verlag, Berlin 1993.
[4] A. FERREOL, E. BOYER, and P. LARZABAL, <<Low cost algorithm for some bearing estimation in presence of separable nuisance parameters>>, Electronic-Letters, IEE, vol 40, No. 15, pp 966-967, July 2004
[5] S. U. Pillai and B. H. Kwon, Forward/backward spatial smoothing techniques for coherent signal identification , IEEE Trans. Acoust., Speech and Signal Processing, vol. 37, pp. 8-15, Jan. 1988
[6] B. Friedlander and A. J. Weiss. Direction Finding using spatial smoothing with interpolated arrays . IEEE Transactions on Aerospace and Electronic Systems, Vol. 28, No. 2, pp. 574-587, 1992.
[7] A. Ferréol, J. Brugier and Ph. Morgand Method for estimating the angles of arrival of coherent sources by a spatial smoothing technique on any array of sensors. Patent published under the number FR 2917180. | A method for jointly determining the azimuth angle θ and the elevation angle Δ of the wave vectors of P waves in a system comprising an array of sensors, a number of waves out of the P waves being propagated along coherent or substantially coherent paths between a source and said sensors, includes at least the following steps: selecting a subset of sensors from said sensors to form a linear subarray of sensors; applying, to the signals from the chosen subarray, an algorithm according to a single dimension to decorrelate the sources of the P waves; determining a first component w of said wave vectors by applying, to the signals observed on the sensors of the chosen subarray, a goniometry algorithm according to the single dimension w; determining a second component u of said wave vectors by applying a goniometry algorithm according to the single dimension u to the signals from the entire array of sensors; determining θ and Δ from w and u. | 6 |
CROSS-REFERENCE TO ATTACHED APPENDIX
Appendix A contains the following files in one CD-ROM (of which two identical copies are attached hereto), and is a part of the present disclosure and is incorporated by reference herein in its entirety:
Volume in drive D is 020129 — 1155
Volume Serial Number is E6C3-5E3C
Directory of d:\
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1/29/02 11:55a <DIR>
1/29/02 11:47a 65,024 $0PN01!.DOC
3 File(s) 65,024 bytes
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A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever.
BACKGROUND
1. Field of the Invention
This invention relates to communications systems such as modems and to methods for detecting or characterizing digital impairment that occurs when communicating via a telephone network.
2. Description of Related Art
ITU standard V.90 defines 56K modems use of digital and PCM (pulse code modulated) signals for downstream communication from a service provider to a home user. For such communications, the telephone system includes a digital network that carries a digital signal, a PCM codec that converts the digital signal to a PCM signal, and telephone wires that bring the PCM signal to the downstream modem. In interpreting a received signal, 56K modems must have a precise model of the PCM codec at the digital/analog network interface and a precise model of the digital impairment over the digital telephone network. Generally, modems communicating via a telephone network can easily identify or distinguish the codec type, e.g., A-law or μ-law, that the telephone network uses, but identifying or distinguishing among every kind of digital impairment of connections can be challenging. 56K modem that fails to identify or learn the digital impairment, can suffer a 30% performance penalty because for accuracy, data transmission must be limited to the worst case scenario. Accordingly, a modem must correctly learn and adjust to the possible digital impairments to provide optimal performance and be commercially successful.
The common digital impairments introduced in telephone networks are well known. For example, for robbed-bit signaling (RBS), networks periodically use the least significant bit (LSB) of a PCM codeword for network control purposes. After using the robbed bits from PCM codewords, the network sets robbed bits to all zeros (even RBS), all ones (odd RBS), or alternates between zero and one (even-odd RBS). Even, odd, and even-odd RBS use the least significant bit of every sixth PCM codeword, but even-odd RBS has a period of twelve codewords because of the alternating replacement of the robbed bit with 1 and 0. RBS may also occur at more than one RBS phase due to multiple signaling in the digital network. Another kind of RBS, called middle RBS, uses a codec that maps each robbed PCM symbol to a level between the level for the PCM symbol with the LSB set to zero and the level for the PCM symbol with the LSB set to one. This document refers to even-odd RBS and middle RBS as strange RBS. Another type of digital impairment known as a digital pad, uses a look-up table that converts each PCM codeword to another PCM codeword to attenuate a signal on a channel.
Typically, the digital impairment can be modeled as a combination of RBS before a digital pad, then the digital pad and then RBS after the digital pad. A middle RBS never happens before a digital pad because middle RBS is implemented at the codec. Even-odd RBS is usually after digital pad. A general model of digital impairment includes six (or twelve) look-up tables, one for each RBS phase. Each look-up table represents the mapping of input PCM codewords to output values during the RBS phase associated with the look-up table.
A modem needs to learn or identify the above-described the digital channel impairments during handshaking to optimally selected a highest possible bit rate that can be accurately transmitted over a channel. However, analog channel impairment makes learning or identifying the digital impairment more difficult. Dealing with the analog impairments is the kernel problem of digital impairment learning.
SUMMARY
In accordance with an embodiment of the invention, short pseudo-random (PR) probing sequences that comply with ITU V.90 digital impairment learning (DIL) descriptors form DIL probing sequences. The short PR probing sequences include subsequences associated with specific codes. Each subsequence contains products of the associated code and a pseudo-random series of values +1 and −1. The pseudo-random nature of the short PR sequences cancels inter-symbol interference (ISI) so that the probing sequences do not require the insertion of extra zero symbols to remove ISI. Additionally, the DIL probing sequences yield high performance in severe inter-symbol interference (ISI) channels.
In accordance with a further aspect of the invention, a novel receiving structure corrects for equalizers that propagate of digital impairment among symbols. The receiving structure can achieve an ISI free receipt of the designed probing sequence within the strict time constraints of the ITU V.90 modem standard. The correction process solves a system of equations based on the wrapped channel response. The wrapped channel response can be determined from information obtained during training of an equalizer for the channel. General digital impairment mapping tables, digital pads, regular and strange RBS patterns, and different types of PCM codecs (A-law/μ-law) can be identified from signals reliably received through the receiving structure.
In accordance with one embodiment of the invention, a DIL process includes receiving a series of samples of a probing signal transmitted through a channel and identifying a set of the samples that corresponds to a selected code. The set corresponds to repeated transmission of the code over the channel, wherein each repetition of the first code has a sign from a pseudo-random series. The DIL process then determines a plurality of averages of the samples from the set. Each average corresponds to an associated phase of robbed bit signaling that occurs in the channel. From the averages, the DIL process can identify the digital impairment in the channel. One method of identifying the digital impairment determines from the averages, specific codes output from a digital network in the channel when the selected code is input to the channel. Determined output codes for the selected code and other input codes provide measured points in a set of mappers that maps input codes to output codes. To find a set of complete mappers for the channel, the measured points can be matched with corresponding points in predetermined maps from a library stored in a memory.
To determine the output codes from the averages, the process includes: determining a scaling factor for the channel; identifying the pulse code modulation (PCM) decoding employed in the channel; scaling the averages by the scaling factor to generate scaled averages; and encoding the scaled averages using an encoding method that corresponds to the identified PCM decoding. The encoded and scaled averages indicate the measured points for the channel's mappers.
Determining the averages may include: determining a plurality of initial averages and then correcting the initial averages. Each initial average is an average of samples corresponding to an associated phase of the robbed bit signaling, and correcting the initial averages corrects for propagation of the digital impairment by an equalizer. To correct for the equalizer, the process determines a wrapped channel response for the equalizer and solves system of equations for the corrected averages. The system of equations equates a vector containing the initial averages with a product of a matrix derived from the wrapped channel response and a vector containing the averages.
In accordance with another embodiment of the invention, a process sends a novel probing signal for detection of digital impairment in a channel. The probing signal corresponds to a probing sequence that includes one or more subsequences. Each subsequence includes repetitions of an associated code, and each repetition is multiplied by an associated value from a pseudo-random series of +1 and −1. The pseudo-random sign for the subsequences cancels ISI. In accordance with another aspect of the invention, an equalization process for digital impairment learning corrects for feedback terms of an equalizer that propagate digital impairment among received values.
Another embodiment of the invention is a communication system that implements any of the processes described herein. Once such system includes a receiver with a mean value estimator, a coding identifier, a scaling estimator, a memory, and a map set identifier. The mean value estimator receives a series of samples representing a probing signal transmitted over a channel and determines a plurality of averages. Each average corresponds to a phase of robbed bit signaling on the channel. The coding identifier receives and processes the averages to identify a coding process (e.g., μ-law or A-law) used in the channel. The scaling estimator receives and processes the averages to identify a scaling factor for the channel. The memory stores entries corresponding to a library of mapper sets with each mapper set defining a correspondence between input codes and output codes from a digital network. The map identifier uses information from the mean value estimator, the scaling estimator, the coding identifier, and the memory to identify an entry in the memory that matches the averages as adjusted for the scaling factor and the coding process. The entry identified indicates the digital impairment in the channel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a model for a channel including digital and analog impairment.
FIG. 2 is a block diagram of a portion of a receiver or modem that in accordance with an embodiment of the invention identifies the digital impairment.
FIG. 3 is a block diagram of a decision feedback equalizer for use in the receiver of FIG. 2 .
FIG. 4 is flow diagram of a digital impairment learning process in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with an embodiment of the invention, a digital impairment learning (DIL) process uses a probing sequence including multiple subsequences. Each subsequence repeats transmission of a code selected for the subsequence, where the sign of the selected code alternates in a pseudo-random fashion. The pseudo-random sequence has a period that is greater than the order of feedback terms used in an equalizer and prime relative to the robbed bit signaling (RBS) period (typically 6 or 12 codes). The pseudo-random nature of the sign tends to cancel inter-symbol interference (ISI) particularly in averages of the received signal. Thus, the probing sequence does not require insertion of zeros to avoid ISI. Further, the number of repetitions of a selected code with the pseudo-random signs is statistically sufficient to cancel channel noise in the averages for the received probing signal at each RBS phase. After repeatedly transmitting the selected code with pseudo-random sign, another code is selected for the next subsequence, and the probing sequence repeats that code with a sign according to the pseudo-random sequence. The full probing sequence includes subsequences for a set of codes transmitted in the same fashion with each code having the pseudo-random pattern of signs.
In accordance with another aspect of the invention, sets digital impairment mappers M(i,X) that satisfy Equation 1 model digital impairments.
X′=M ( i,X ) Equation 1
In Equation 1, code X is the code value input to the digital network, index i ranges over the RBS phases (e.g., 0 to 5 or 11), and value X′ is the output value from the digital network after the digital impairment but before PCM encoding. A digital impairment learning (DIL) process uses the above-described probing sequence to identify the set of mappers for a channel. The DIL process includes estimating mean or average values <Y(i,X)> from the received PCM signals, estimating a receiver scaling factor S, identifying the PCM encoding method of the channel, determining measured points for the mappers associated with the channel. The mean value estimation averages the repetitions of received values for the same code to reduce the effect of channel noise and ISI. Use of the pseudo-random signs in the probing sequence makes inserting zeros in the probing sequence unnecessary. Thus, the probing sequence more effectively uses the allotted time for digital impairment learning. In accordance with a further aspect of the invention, a DIL process compensates for an equalizer to provide averages that are almost ISI free.
The DIL process determines the scale factor S before identifying the digital impairment. At the same time, the codec type and presence of strange RBS are identified. From average values <Y(i,X)> of the received signal and the scaling factor S, multiple measured points m(i,X) are determined for the digital impairment mappers M(i,X). An exhaustive matching method matches measured points m(i,X) that were determined from the probing signal with associated points for predetermined impairment mappers M(i,X) that are stored in memory of the receiver. Finding matching mappers M(i,X) identifies RBS patterns and digital pads.
FIG. 1 illustrates a model of a transmission channel including a digital channel model 110 and an analog channel model 130 in series. The channel uses a PCM communication protocol such as the ITU V.90 modem standard. Digital channel model 130 includes impairments resulting from initial robbed bit signaling 112 , followed by a pad operation 114 , and then further robbed bit signaling 116 . As a result of the digital impairments, the input code X becomes a digital value X′ which satisfies Equation 1 for some set of mappers M(i,X). A set of mappers M(i,X) can more generally describe any digital impairment and is not limited to the initial RBS 112 , digital pad 114 , and further RBS 116 of FIG. 1 . However, describing an arbitrary channel typically requires six mappers M(i,X), one for each RBS phase, of 128 input codes X. To completely measure the mappers for each code X and phase i during a DIL process, the DIL process needs to solve for 768 variables X′ which define mappers M(i,X). However, the ITU standard V.90 restricts the probing sequence for the DIL process to under five seconds, and 768 variables is a large number of variables with which to deal in the allotted time.
One DIL process in accordance with an embodiment of the invention only identifies or measures some of the values X′ from the probing sequence. The DIL process then matches the determined values X′ to values from predetermined mappers Mj(i,X). The predetermined mappers Mj(.,.) form a library that is stored in memory. Describing all possible combinations of different RBSs 112 and 116 and digital pad 114 would require a large library. Accordingly, to save memory space, the most common sets of mappers Mj(.,.) correspond to the most likely combinations of RBS and digital pads, can be predetermine and stored as look-up tables in memory of the modem. Once a mapper M(i,X) is identified for a particular channel, the receiver can use that mapper M(i,X) in decoding of received data. Alternatively, the library only contains entries consisting of the points for comparison to the measured points. Upon finding a matching entry, the full set of mappers or the appropriate rule for decoding can be determined.
Before the data reach the receiving modem, a PCM decoder 118 decodes the value X′ according to a well known decoding rule Dx(.). A decoded value Dx(X′) represents the output of PCM decoder 118 corresponding to input value X′. The subscript x in decoding Dx(.) is an index for the type of decoding that PCM decoder 118 performs. CCITT standard G. 711 defines the operation of PCM decoder 118 at the interface between a digital network (digital channel model 110 ) and an analog telephone line (analog channel model 130 ). In particular, decoding Dx(.) follows one of four possible decoding rules, Dμ(.) for μ-law decoding, Da(.) for A-law decoding, Dmμ(.) for modified μ-law decoding, and Dma(.) for modified A-law decoding. The μ-law and A-law decodings Dμ(X′) and Da(X′) are well known. The modified μ-law and A-law decodings result from middle RBS where a code subjected to bit robbing decodes to the mean of the decoded values for consecutive codes (i.e., codes that are the same except for their least significant bits). For example, the μ-law decoding has Dμ(50), Dμ(51), Dμ(78) and Dmμ(79) equal to 1052, 1116, 3772, and 3900 respectively, and the modified μ-law decoding has Dmμ(50) and Dmμ(51) equal to (1052+1116)/2 or 1084 and Dmμ(78) and Dmμ(79) equal to (3772+3900)/2 or 3836 during phases subject to bit robbing. Each decoding Dx(.) has a domain including 256 signed values (e.g., 8-bit codes X′).
A linear digital-to-analog converter 120 converts value Dx(X′) to an analog voltage that is proportional to value Dx(X′) and drives the analog voltage on analog channel 130 for the sample period to generate part of an analog communication signal Atx. Analog channel model 130 introduces analog impairments including distortion or inter-symbol interference (ISI) 132 , attenuation or scaling 134 , and noise 136 which change analog signal Atx to a received analog signal Arx. The analog impairments 132 , 134 , and 136 depend on the physical media (e.g., copper telephone wires). A receiver typically includes an equalizer that is trained to remove or reduce the distortion or ISI 132 .
FIG. 2 illustrates a portion of a receiver 200 implementing a DIL process in accordance with an embodiment of the invention. Receiver 200 includes an analog-to-digital converter (ADC) 210 , an equalizer 220 , and a DIL block 230 . ADC 210 is a linear converter that generates a series of digital samples Y′ representing the received probing signal. Equalizer 220 is a digital filter that at least partly corrects for distortion or ISI 132 in the analog portion of the channel. Methods for creating or training equalizers including filters such as FIR or IIR filters are known in the art.
Currently, decision feedback equalizers (DFE) are popular. FIG. 3 illustrates a DFE 300 suitable for use as equalizer 220 of FIG. 2 . DFE 300 sums a series of feed-forward terms and feedback terms. The feed-forward terms are products of filter coefficients f( 0 ) to f(n−1) and input values Y′ having respective delays of 0 to n−1 sampling periods. The feedback terms are products of filter coefficients b(1) to b(m−1) and output values Y of DFE 300 that have passed through a slicer 310 and been delayed of 1 to m−1 sampling periods respectively. Slicer 310 rounds output value Y to the nearest decoded value from PCM decoder 118 . Given a channel response h(D) where index D is the delay relative to a current received sample, an adaptive DFE 300 satisfies Equation 2.
h ( D ) f ( D )= b ( D ) Equation 2
In Equation 2, b(D) is monic, i.e., the first coefficient b( 0 ) is 1. An equalizer such as DFE 300 can fail or perform poorly during a DIL process, even if the equalizer perfectly compensates for analog impairments. This is because the decision feedback terms introduce the digital impairments of previous symbols into a current symbol and in turn propagate impairments into future symbols. In accordance with an aspect of the invention, a receiving structure can replace or augment equalizer 220 during a DIL process to reduce or remove propagation of digital impairment from one sample to other samples.
DFE 300 uses the coefficients for feed-forward and feedback to filter samples received during normal operations of a receiver after digital impairment learning. However, during digital impairment learning, equalizer 220 does not use the feedback terms when generating filtered samples Y for DIL block 230 . Equalizer 220 uses only the feed-forward terms during digital impairment learning, and as described below DIL block corrects for the feedback terms in a manner that reduces ISI and propagation of RBS or digital impairment from one same to following samples.
DIL block 230 can be implemented in software, firmware or dedicated hardware using techniques well known for communication systems and digital processing. DIL block 230 includes a mean value estimator 232 , a scaling factor estimator 234 , a PCM coding identifier 236 , and a map identifier 238 . Mean value estimator 232 averages the absolute values of received samples Y for an input code X to determine an average <Y(i, X)> for each RBS phase (e.g., i=0 to 5). (As described further below, when determining averages <Y(i,X)>, estimator 232 may also compensate for digital impairments that equalizer 220 propagates among samples.) To determine the averages, mean value estimator 232 identifies a set of samples Y with an associated code X, identifies an RBS phase i corresponding to each phase, multiplies each sample by +1 or −1 to remove sign associated with the pseudo-random sequence, and accumulates the averages <Y(i,X)> for each RBS phase i and transmitted code X. As noted above, the averaging reduces the effect of channel noise and ISI. Since the period for RBS is either 6 or 12 codes, mean value estimation block 232 determines the averages <Y(0,X)> to <Y(6,X)> using six sums for each code X. With six RBS averages, even-odd RBS has the same effect as either modified μ-law or modified A-law (i.e., the other strange RBS). If strange RBS is detected, the type of the strange RBS can be subsequently identified. Alternatively, the presence of even-odd RBS can be detected or ruled out using 12 averages for a transmitted value during equalizer training or DIL.
After estimator 232 finds the averages <Y(i,X)> for one or more codes X, scaling factor estimator 234 finds receiver scaling factor S, and coding identifier block 236 identifies the encoding Ex(.) for the telephone network. In one embodiment, estimator 234 and identifier block 236 determine a measure of the error for a set of proposed scaling factors S and encodings Ex(.) and select the combination that provides the smallest error. Alternatively, whether the codec is a μ-law or A-law codec can be identified from the shape of a plot of averages <Y(i,X) verses input codes X. Both scaling factor estimator 234 and coding identifier 236 can use information from the DIL sequence and from a prior training sequence for equalizer 220 .
Outputs from scaling estimator 234 and coding identifier 236 are respectively the scaling factor S and an encoding Ex(.) for the channel. Encoding Ex(.) is the inverse of the decoding Dx(.) of PCM decoder 118 (FIG. 1 ). Multiplying averages <Y(i,X)> by the scaling factor S and applying the identified encoding Ex(.) provides measured mapper points m(i,X) for the channel. Map identifier 238 compares measured mapper points m(i,X) to points from a set of predetermined mappers Mj(.,.) in a memory 235 . For the predetermined mappers Mj(.,.), j is an arbitrary index that distinguishes mappers corresponding to different digital impairments. An exhaustive matching method compares the measured mapper points m(i,X) to the same points in the predetermined mappers Mj(.,.) to identify a matching mapper M(.,.). The complete mapper M(.,.) can be used in decoding received data if match is found. The index j of the identified mapper indicates the RBS pattern and digital pad for the channel and the maximum number of bits that can be transmitted during each RBS phase.
FIG. 4 shows a flow diagram of a digital impairment learning process 400 in accordance with an embodiment of the invention. DIL process 400 begins after training of equalizer 220 of FIG. 2 using conventional training techniques. Step 410 determines averages <Y(i,Uref)> for a code Uref and each RBS phase i. Code Uref is a code that is transmitted during equalizer training. The relatively long duration of equalizer training provides high statistic for the averages <Y(i,Uref)> at each RBS phase.
For DIL, a transmitter sends a probing signal based on a selected set of codes X. For each code X in the selected set, the transmitter repeatedly sends a codes ±X with signs changing according to a periodic, pseudo-random (PR) sequence prs(.). The size of the selected set depends on the time available for the DIL probing signal and the length of the PR sequence prs(.). The specific codes X in the selected set can be randomly distributed from the range of codes or selected to provide the best resolution when distinguishing the predetermined mappers as described below.
PR sequence prs(.) has a period that is prime relative to the RBS period P and greater than the order of the decision feedback terms b(D) of the equalizer. Table 1 shows an exemplary subsequence that corresponds to a single code X.
TABLE 1
Exemplary Porbing Series for Code X
Index j
0
1
2
3
4
5
6
7
8
9
Phase i
0
1
2
3
4
5
0
1
2
3
Code
+X
−X
−X
+X
−X
+X
+X
+X
−X
−X
prs(.)
+1
−1
−1
+1
−1
+1
+1
+1
−1
−1
10
11
12
13
14
15
16
17
18
19
20
21
4
5
0
1
2
3
4
5
0
1
2
3
+X
−X
+X
+X
+X
−X
−X
+X
−X
+X
+X
+X
+1
−1
+1
+1
+1
−1
−1
+1
−1
+1
+1
+1
22
23
24
25
26
27
28
29
30
31
32
33
4
5
0
1
2
3
4
5
0
1
2
3
−X
−X
+X
−X
+X
+X
+X
−X
−X
+X
−X
+X
−1
−1
+1
−1
+1
+1
+1
−1
−1
+1
−1
+1
34
35
36
37
38
39
40
41
4
5
0
1
2
3
4
5
+X
+X
−X
−X
+X
−X
+X
+X
+1
+1
−1
−1
+1
−1
+1
+1
In Table 1, the pseudo-random sequence of signs prs(.) has a period of 7 codes which is prime relative to the RBS period P (6 codes) and is repeated P times. Each code X in the probing sequence has a similar 42 code subsequence. The V.90 protocol allows the receiver to indicate the desired probing signal using DIL descriptors and the probing sequence can cover 112 codes X from 0 to 111 . The remaining codes from 112 to 128 are unlikely to be used because of the power constraints placed on transmissions. However, the mappings for codes 112 to 128 can be determined by finding a match with a predetermined set of mappers as described further below.
A receiver, in step 425 , receives a value Y corresponding to the subsequence for a code X. The value Y is a filtered value from equalizer 220 , but the filter operation for DIL uses only the feed-forward terms and does not use the feedback terms. In step 420 , the receiver uses Equation 3 to accumulate the value Y into the appropriate initial average y(i) for the current RBS phase i. Equation 3 : y ( i ) = ∑ n = 0 to P - 1 Y ( i + 6 n ) * prs ( i + 6 n ) for i = 0 to 5.
The averages of Equation 3 assume a RBS period of six. In the averages, even-odd RBS, which alternates replacing a robbed bit with 0 and 1, has the same effect as do modified μ-law or modified A-law decoding. As described further below, if strange RBS is detected further processing is required to distinguish even-odd RBS from modified μ-law or modified A-law decoding.
Step 425 determines where received value Y is the last for the subsequence corresponding to a value X. If the received value Y is not the last value associated with a code X, DIL process 400 branches from step 425 , back to steps 415 to receive the next value Y and then accumulate the next value into the appropriate average. If the received value Y was the last for a code X, the initial averages are complete, and process 400 moves to step 430 to correct the initial averages as described further below.
Each value Y is subject to intersymbol interference (ISI), channel noise, and attenuation or other changes in scale in the analog channel. In accordance with an aspect of the invention, the pseudo-random signs of code X cause partial cancellation of intersymbol symbol interference in individual values Y and in averages y(i) of the values Y. Repetition of the code X helps cancel the noise in the averages y(i). Use of the equalizer on input values Y′ to generate received values Y also helps remove ISI from averages y(i), but may be incomplete because feedback terms are not use. However, if the feedback terms of the equalizer were used, the equalizer could undesirably propagate digital impairments among the RBS phases.
In accordance with an embodiment of the invention, step 430 corrects for the feedback terms not being used in the equalizer and does so in a manner that reduces propagation of digital impairment. In particular, step 430 corrects the initial averages y(i) using Equations 4 and 5. Equation 4 gives the wrapped channel response with period six (Bi) for a decision feedback filter b(D) having coefficients b(0) to b(m−1) which are determined during training of the equalizer. Equation 4 : Bi = ∑ all j with Mod ( j , 6 ) = i b ( j ) for i = 0 to 5.
Equations 5, which attempt to correct the equalizer and ISI, represent a system of equations that are solved for final averages <Y(i,X)> for a current code X and each RBS index i from 0 to 5. Equation 5 : N - B0 - B1 - B2 - B3 - B4 - B5 〈 Y ( 5 , X ) 〉 y ( 5 ) - B5 N - B0 - B1 - B2 - B3 - B4 〈 Y ( 4 , X ) 〉 y ( 4 ) - B4 - B5 N - B0 - B1 - B2 - B3 〈 Y ( 3 , X ) 〉 = y ( 3 ) - B3 - B4 - B5 N - B0 - B1 - B2 〈 Y ( 2 , X ) 〉 y ( 2 ) - B2 - B3 - B4 - B5 N - B0 - B1 〈 Y ( 1 , X ) 〉 y ( 1 ) - B1 - B2 - B3 - B4 - B5 N - B0 〈 Y ( 0 , X ) 〉 y ( 0 )
During step 430 , estimator 232 operates on initial averages y(i) for code X in the DIL probing signal. Estimator 232 can also find averages <Y(i,Uref)> for code Uref using Equations 4 and 5, but correction is less essential for averages <Y(i,Uref)> because of the high statistic that equalizer training permits for these average.
After estimator 232 determines the averages <Y(i,X)> for the current code X, step 440 determines whether the current code X is the last code in the probing sequence. If not, process 400 branches back step 415 and uses steps 415 , 420 , 425 , and 430 to determine averages <Y(i,X)> for the next code X from the DIL probing sequence. Once all the averages <Y(i,X)> are known, process 400 branches from step 440 to step 450 to determine an error for a proposed combination of scaling factor S and decoding Dx.
The scaling factor S can be determined from the ratio of an average value <Y(i,X)> and the value Dx(X′) transmitted. The average <Y(i,Uref)> provides the highest statistics for determination of the scaling factor, but Dx(Uref) is unknown because the decoding Dx(.) and the digital impairment which converts code Uref to Uref are originally unknown. For a set of digital impairments having pads up to 6Db, reference code Uref maps to 30 different codes Uref+1 to Uref−28. For step 450 , a code k from the set {Uref+1 , Uref, . . . , Uref−28} and a decoding Dx(.) are selected. (A larger set of potential codes k can be considered if more types of digital impairment or larger digital pads are a concern.) With k and Dx(.) selected, Equation 6 gives a candidate scaling factor S. Equation 6 : S = 〈 Y ( i , Uref ) 〉 Dx ( k )
If the correct coding Dx(.) was selected and the appropriate codes k are selected for the RBS phases i, the scaling factors S is approximately the same for every RBS phase.
The correct decoding Dx(.) and codes k are the ones that provide the least error in predicting the measured averages <Y(i,X)>. Equation 7 gives a weighted mean squared error MSEx(i,k) for a RBS phase i, when comparing measured averages <Y(i,X)> to expected averages calculated using the selected k and Equation 7 : MSEx ( i , k ) = 1 { size of J } * ∑ { j in J } ( 〈 Y ( i , Uref ) 〉 Dx ( k ) ) 2 * ( Qex [ ( Dx ( k ) ) * 〈 Y ( i , j ) 〉 〈 Y ( i , Uref ) 〉 ] ) 2
In Equation 7, set J is a subset of the codes X in the DIL sequence and is typically equal to the set of all codes X transmitted during the DIL probing sequence. Function Qex[.] is the quantization error as defined in Equation 8.
Qex[Y]=Dx ( Ex ( Y ))− Y Equation 8
In Equation 8, index x is μ, a, mμ, or ma to indicate μ-law, A-law, modified μ-law, or modified A-law.
Step 450 determines the error for a possible combination of RBS phase i, code k, and decoding Dx(.). Step 460 determines whether the error has been determined for every combination of i, k, and Dx(.). If not, process 400 branches from step 460 , through step 465 , back to step 450 and determines the error for the next combination of i, k, and Dx(.). After determining the error for the last combination of i, k, and Dx(.), process 400 moves from step 460 to step 470 and selects a scaling factor and a decoding. In particular, for each value of RBS phase i, step 470 identifies a combination of k and Dx that gives the least error as determined in step 450 . Scaling factors for each RBS phase can then be determined from Equation 6. Usually, the best scaling factors S for the RBS phases are very close to each other and the actual scaling factor S. Occasionally, if the factors are quite different, a retraining operation can be initiated to start digital learning again. The best decoding Dx(.) should be the same for all RBS phases, except that μ-law (or A-law) decodings may be mixed with strange RBS, i.e., modified μ-law (or A-law) or even-odd RBS. A mixture of μ-law and A-law being best for different RBS phase indicates a need for retraining.
If process 400 identifies strange RBS, the process determines averages for a 12-sample RBS period. If averages that are six RBS phase apart are the same, the strange RBS is modified μ-law or modified A-law. If averages that are six RBS phase apart are significantly different, the strange RBS is modified even-odd RBS.
After determining the scaling factor S and the decoding Dx(.), step 475 determines the measured map points corresponding to the determined corrected averages. More specifically, Equation 9 indicates the measured point m(i,X) in terms of the determined scaling factor S, the identified encoding Ex, and the averages <Y(i,X)>.
m ( i,X )= Ex ( S*<Y ( i,X )>) Equation 9
Once the measured points m(i,X) are known, step 480 searches through a library of predetermined mappers corresponding to specific digital impairments to find mappers matching the identified mapper points. In one embodiment the predetermined mappers include all mappers corresponding to no digital pad, some 3 dB pads, and some 6 dB pads sandwiched by all possible RBS patterns. The set of identified mappers from the library has associated a known RBS pattern and digital pad. The full mappers M(.,.) can be reconstructed if a precise combination of digital impairments is identified.
In a matching set of predetermined mappers is found, the receiver can use the predetermined mappers in decoding of received samples Y. If no matching predetermined mappers are found, the receiver can use the measured mapper points m(i,X) in decoding received samples. As noted above, DIL for the V.90 protocol can use a probing sequence and measure mapping points covers the most likely codes (e.g., −111 to +111) to be used for conveying data.
The appendix includes a listing of a software implementation of a DIL receiver system that is compliant with the ITU V.90 modem standard and implements a DIL process in accordance with an embodiment of the invention.
Although the invention has been described with reference to particular embodiments, the description is only an example of the invention's application and should not be taken as a limitation. For example, although the description mainly uses the example of probing signals where one code is consecutively transmitted with a pseudo-random sign, codes transmitted in a probing signal can be order or mixed in a variety of ways. For example, alternative embodiments can employ two or more codes that are interwoven and transmitted with pseudo-random signs. Various other adaptations and combinations of features of the embodiments disclosed are within the scope of the invention as defined by the following claims. | Short pseudo-random (PR) probing sequences that comply with ITU V.90 digital impairment learning (DIL) descriptors provide DIL probing sequences that yield high performance in severe inter-symbol interference (ISI) channels. The short PR sequences do not require the insertion of extra zero symbols to get rid of ISI. Further, a novel receiving structure corrects for propagation of digital impairment common in conventional equalizers for an ISI free receipt of the probing sequences within the strictly time constrained probing sequence. Based on the reliably received signals, general digital impairment mapping tables, digital pads, regular and strange RBS patterns, and different types of PCM codecs (A-law/μ-law) are identified. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to coated water-vapor-pervious and fungus-resistant wovens, especially industrial wovens, to a process for producing same and, to their use for the production of sun protection and weather protection articles such as tent materials, boat covers and the like.
[0003] 2. Related Technology
[0004] Water-vapor-pervious textile fabrics are known in particular from the use sectors of functional sports and protective clothing and also various medical sectors. Common processes for producing water-vapor-pervious textiles from the sectors cited above are known in particular under the designations of “Goretex” and “Sympatex,” which work according to the principle of producing microporous structures.
[0005] Watertight yet moisture-pervious coated textile fabrics and processes for their production are inter alia described in DE 2948892 C2. The processes described therein utilize a polyurethane solution in an organic solvent, producing the microporous layer of polyurethane by coagulation.
[0006] Further processes for producing polyurethane-coated textile fabrics which are breathable and water repellent are described for example in DE 3633874 C2. The process described in this patent specification utilizes two aqueous polyurethane dispersions which are applied in succession wet on wet.
[0007] However, it has been determined that the water vapor transmission rate is not always satisfactory. In addition, condensates form very frequently in the pores of the coatings. One of the disadvantages of this is that fungi form in these condensates. Inevitably, fungi will also spread in those spaces which are actually to be protected by the coated wovens. Unsightly matt deposits form on the fittings of the interior spaces of ships such as yachts and the like and confer an unsightly appearance on objects in the interior.
[0008] It is another frequent occurrence, when thus coated textiles are used as a covering on ships and the coverings develop dents or dips in which water can collect, that the water pressure on the coated textile will increase over time to such an extent that water in liquid form as well as in vapor form is able to pass through the coated woven and get into interior to be protected.
[0009] Although there already are a whole series of water-vapor-pervious polyurethane-coated wovens, there is still a need for improved polyurethane-coated wovens and for simple processes for their production and in particular for coated wovens which are particularly useful for producing sun protection and weather protection articles.
SUMMARY OF THE INVENTION
[0010] The invention provides a process for producing such coated fabrics, which possess good water vapor perviousness and good water pressure resistance, and in addition possess improved fungus protection properties, are oil, soil, and water-repellent, and which in addition are also weathering-resistant.
[0011] Accordingly, the invention provides a process for producing coated water-vapor-pervious and fungus-resistant wovens, wherein a washed woven is impregnated with an aqueous impregnant containing a fungicide and a hydrophobicizer, dried, then coated with an aqueous dispersion of a polyurethane likewise containing a fungicide without further additives such as new color-conferring additives, dried and subsequently reimpregnated with an aqueous hydrophobicizer and dried.
DETAILED DESCRIPTION
[0012] The aqueous impregnant preferably comprises 1%-5% and especially 2%-4% by weight of fungicide. The aqueous impregnant advantageously contains 0.2% to 2% and preferably 0.4% to 1% by weight of a hydrophobicizer.
[0013] The aqueous dispersion preferably contains hydrophilic polyurethanes.
[0014] It is further advantageous when the impregnated and dried woven is at least once coated with an aqueous polyurethane dispersion.
[0015] It is further advantageous when the impregnating is effected by pad-mangling or spraying.
[0016] The invention further provides coated water-vapor-pervious and fungus-resistant wovens producible by one of the processes indicated above.
[0017] The wovens of the invention preferably have a water vapor transmission rate of 800 to 2800 g/m 2 ×24 h at 20-50° C.
[0018] Of particular advantage are coated, water-vapor-pervious and fungus-resistant wovens having a water pressure resistance of 800 to 1800 mm hydrohead.
[0019] The process of the invention can be carried out as follows.
[0020] The initial step is to produce a woven fabric in a conventional manner. The wovens are in particular industrial wovens, which have a higher basis weight and tensile strength than wovens for purely textile purposes. The basis weight of the wovens is advantageously in the range from 150 to 450 g/m 2 .
[0021] The woven is then cleaned, for example by washing it in the loom state by means of a jigger or continuous washing process, to remove in particular residual spin finish and the like.
[0022] The woven thus washed and dried is then impregnated with an aqueous impregnant. This impregnant comprises one or more fungicides and also one or more hydrophobicizers. The woven is then impregnated so thoroughly that the fibers and yarns are fully enveloped by impregnant. This is necessary to obtain uniform coating in the subsequent coating process.
[0023] After the impregnating step, the woven thus impregnated is dried. The fungicide is generally present in the impregnant in an amount of 20-40 g preferably 30 g per liter of water. The impregnant further comprises a hydrophobicizer in an amount of for example 4-10 g especially 7 g per liter of water.
[0024] After the impregnating step, the woven thus impregnated and dried is coated. Aqueous dispersions of hydrophilic polyurethanes are used for coating. The aqueous dispersion shall comprise sufficient polyurethane to ensure that an adequate amount of polyurethane is applied to the woven. The amount is advantageously determined such that the fabric comprises between 30 and 50 g of coating add-on per square meter of area, these indications of amount relating to polyurethane solids.
[0025] The aqueous coating further contains a fungicide, preferably the same fungicide, or else if appropriate a fungicide which is similar or of the same type, as used in the impregnation. The coating may further contain customary additives, such as color pigments for example.
[0026] Once a sufficient and uniform coating has been applied to the woven, the woven is dried and is then subjected to a further impregnation with an aqueous system containing a hydrophobicizer, preferably 3 to 5 g per 100 g of aqueous composition. This reimpregnation provides an improvement in oil, water and soil repellency.
[0027] Wovens thus coated possess in particular good water vapor perviousness, a high water pressure resistance, good oil, soil and water repellency and also excellent fungus resistance. These performance characteristics last throughout the entire use life, so that the protected interior likewise remains protected against moisture and fungal colonization.
[0028] The wovens thus coated are very useful according to the invention for solar protection and weather protection articles. To be identified in particular here are tent materials, tent roofs, beer tent fabrics, boat covers, boat winter storage covering, boat summer covering, sprayhoods in the boat sector, bow protection panes on boats, including in particular those sheetlike structures which are intended to protect on-boat rooms and spaces, for example cabins, against moisture and fungus formation.
[0029] The yarns for the wovens may utilize polyester, in particular polyethylene terephthalate filaments and fibers, for example filament yarns, continuous filament fibers or staple fiber yarns, fibers composed of acrylics, cotton and also blends of synthetic sand natural fibers or manufactured fibers such as cellulosic fibers.
[0030] Useful further ingredients to be added at impregnation or coating include customary additives, for example color pigments.
[0031] The example which follows illustrates the invention:
EXAMPLE
[0032] The base fabric to be finished in this operative example is a woven acrylic fiber fabric having a basis weight of about 300 g/m 2 , this fabric having been produced from spun-dyed staple fiber yarns.
[0033] The substrate is washed in a first step of the process by means of a jigger or continuous washing process to remove residual substances such as spin finishes from the loom state fabric.
[0034] The next step consists in a preimpregnating operation which insures, on the one hand, that the coating film can be uniformly applied in the subsequent coating process and, on the other, the fungicide is uniformly distributed in the fabric.
[0035] In this preimpregnating operation, the fungicide is present in an amount of 20 to 40 g—preferably 30 g—per liter of water and a hydrophobicizer is present in an amount of 4 to 10 g—for example 7 g—per liter of water.
[0036] The effect of the hydrophobicizer is that the coating is applied as a film on the surface of the fabric in the next step.
[0037] The subsequent coating process provides for uniform application of a water-vapor-pervious polyurethane—namely a hydrophilic aliphatic polyurethane—(or else a mixture of this polyurethane with another polyurethane) in the form of an aqueous dispersion in a one-pass process, the amount applied to the fabric being between 30 and 50 g/m 2 —preferably 40 g/m 2 .
[0038] This amount is to be understood as meaning that amount of solids which is present in dissolved form in an aqueous solution of 100 g total weight which is used per m 2 of fabric to be coated.
[0039] The coating, i.e. the aqueous dispersion, further comprises the fungicide of the same type in a concentration of 3% to 5%-4% for this example—i.e. 4 g in 100 g of aqueous dispersion.
[0040] Finally, the fabric thus coated is subjected to a reimpregnation through a customary pad-mangling process in which the hydrophobicizer is again present in an amount of 4 g of 100 g of aqueous solution, whereby adequate oil, water and soil repellency is additionally achieved on the textile end product. | Coated, water-vapor-pervious and fungus resistant wovens, their production and also their use as sun and weather protection articles, a precleaned industrial woven fabric being treated at least once with an aqueous impregnant comprising a fungicide and a hydrophobicizer. The fabric thus impregnated and then dried is subsequently coated with an aqueous polyurethane dispersion which likewise contains a fungicide. After drying, the coated fabric is reimpregnated. The wovens are notable for fungus resistance, good water vapor perviousness and good watertightness against a high hydrohead in particular. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a semiconductor package and a fabrication method thereof and, more particularly, to a multi-chip module having bonding wires and method of fabricating the same.
2. Description of the Related Art
As portable electronic devices become smaller, the dimensions of semiconductor packages in the electronic devices must also be reduced. To help accomplish this, a multi-chip module technique is widely used because it can increase the capacity of the semiconductor package. Multi-chip modules (MCMs) include a plurality of chips, which are stacked.
FIG. 1 is a cross sectional view illustrating a conventional multi-chip module having bonding wires.
Referring to FIG. 1 , a bottom chip 3 and a top chip 7 are sequentially stacked on a substrate such as a lead frame or a printed circuit board. The substrate includes a flat body 1 and a first group of interconnections 1 a and a second group of interconnections 1 b formed on a surface of the body 1 . The bottom chip 3 is attached and fixed to the body 1 using an adhesive 5 , which is interposed between the bottom chip 3 and the body 1 . Spacers 9 are interposed between the top chip 7 and the bottom chip 3 in order to separate the top chip 7 from the bottom chip 3 . The bottom chip 3 has a plurality of pads 3 a formed on its edges.
The pads 3 a are electrically connected to the first group of interconnections 1 a through a first group of bonding wires 13 . In this case, the first group of bonding wires 13 may be in contact with a backside surface of the top chip 7 if the top chip 7 has the same dimension as the bottom chip 3 . Thus, the spacers 9 should have a sufficient height to prevent the first group of bonding wires 13 from being in contact with the backside of the top chip 7 . In other words, a distance S between the bottom chip 3 and the top chip 7 should be determined in consideration of the height of the first group of bonding wires 13 . Accordingly, there is a limitation in reducing the total thickness of the multi-chip module.
Further, the top chip 7 has a plurality of pads 7 a formed on its edges. The pads 7 a are electrically connected to the second group of interconnections 1 b through a second group of bonding wires 15 . The space between the bottom chip 3 and the top chip 7 is filled with an insulator 11 .
FIG. 2 is a cross sectional view illustrating another conventional multi-chip module having bonding wires.
Referring to FIG. 2 , a bottom chip 23 and a top chip 27 are sequentially stacked on a substrate such as a lead frame or a printed circuit board. The substrate has the same configuration as the substrate described in FIG. 1 . That is to say, the substrate includes a flat body 21 and a first group of interconnections 21 a and a second group of interconnections 21 b formed on a surface of the body 21 . Also, the bottom chip 23 is attached and fixed to the body 21 using an adhesive 25 , which is interposed between the bottom chip 23 and the body 21 . An insulator 29 is interposed between the chips 23 and 27 in order to separate the top chip 27 from the bottom chip 23 . The bottom chip 23 has a plurality of pads 23 a formed on its edges.
The pads 23 a are electrically connected to the first group of interconnections 21 a through a first group of bonding wires 31 . In this case, the first group of bonding wires 31 may be in contact with a backside surface of the top chip 27 if the top chip 27 has the same dimension as the bottom chip 23 . Thus, the insulator 29 should have a sufficient thickness to prevent the first group of bonding wires 31 from being in contact with the backside of the top chip 27 . In other words, a distance S between the bottom chip 23 and the top chip 27 should be determined in consideration of the height of the first group of bonding wires 31 . Accordingly, there is a limitation in reducing the total thickness of the multi-chip module.
Further, the top chip 27 has a plurality of pads 27 a formed on its edges. The pads 27 a are electrically connected to the second group of interconnections 21 b through a second group of bonding wires 33 .
In the meantime, a multi-chip module is taught in U.S. Pat. No. 6,333,562 B1 to Lin, entitled “Multichip module having stacked chip arrangement”. In addition, U.S. Pat. No. 6,388,313 B1 discloses a multi-chip module having a bottom chip and a top chip, which are sequentially stacked.
According to the aforementioned conventional MCMs, it is difficult to prevent bonding wires connected to the bottom chip from contacting the backside surface of the top chip. Therefore, it is difficult to realize a thin and reliable package module.
SUMMARY OF THE INVENTION
It is therefore a feature of the present invention to provide thin and reliable multi-chip modules (MCMs) having bonding wires.
It is another feature of the invention to provide methods of fabricating these thin and reliable MCMs having bonding wires.
According to an aspect of the invention, a multi-chip module is provided. The multi-chip module comprises a substrate and a plurality of chips sequentially stacked on the substrate. The substrate includes a plurality of interconnections formed on a top surface thereof. The plurality of chips comprises a lowest chip and at least one top chip. Each of the chips has a plurality of pads formed on the periphery or edges of a front surface thereof. In addition, the top chip stacked above the bottom chip each have an insulating tape, which is attached to its backside. An insulator is interposed between the chips. The insulator preferably has a smaller width than the chips to expose the pads. The pads of the lowest chip are electrically connected to a first group of interconnections on the substrate through a first group of bonding wires. Similarly, the pads of additional chips above the lowest chip are electrically connected to additional groups of interconnections through respective groups of bonding wires.
The top chip may have a greater planar area than a lower chip located under it. Alternatively, all the chips may have substantially the same dimensions, and have their edges aligned.
In an embodiment of the invention, the multi-chip module comprises a substrate with a bottom and top chip sequentially stacked on the substrate. The substrate includes first and second groups of interconnections on a top surface thereof. Each of the chips has pads formed on edges of a front surface thereof. In addition, the top chip includes an insulating tape, which is attached to its backside. An insulator is interposed between the top chip and the bottom chip. The insulator preferably has a smaller width than the chips, thereby leaving the pads of the bottom chip exposed. The pads of the bottom chip are electrically connected to the first group of interconnections through a first group of bonding wires. Similarly, the pads of the top chip are electrically connected to the second group of interconnections through a second group of bonding wires.
The substrate may be a lead frame or a printed circuit board. The top chip can have the same dimension as the bottom chip, or, alternatively, the top chip may have a greater planar area than the bottom chip.
According to another aspect of the invention, a fabrication method of a multi-chip module is provided. The method comprises preparing a substrate and mounting a bottom chip on the substrate. The substrate includes first and second groups of interconnections formed on a top surface thereof. The bottom chip is also mounted on the top surface. The bottom chip pads, which are formed on the edges its front surface, are connected through a first group of bonding wires to the first group of interconnections on the substrate. An insulator is then formed on the upper surface of the bottom chip in a manner to leave the pads on its edges exposed. Next, a top chip is mounted on the insulator. The top chip has an insulating tape attached to its backside. Thus, the insulating film may be in contact with the insulator. The top chip also has pads formed on edges its front surface, which are connected through a second group of bonding wires to the second group of interconnections on the substrate.
Conductive bumps may be additionally formed on the pads of the bottom chip prior to connection with the first group of bonding wires. In this case, the first group of bonding wires are connected to the pads through the bumps and are preferably formed using a bump reverse bonding technique.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features and advantages of the present invention will become more apparent to those of ordinary skill in the art by describing embodiments of the present invention in detail with reference to the attached drawings, in which:
FIG. 1 is a cross-sectional view illustrating a conventional multi-chip module;
FIG. 2 is a cross-sectional view illustrating another conventional multi-chip module;
FIG. 3 is a cross-sectional view illustrating a multi-chip module according to an embodiment of the present invention; and
FIGS. 4 to 6 are cross-sectional views for describing a method of fabricating a multi-chip module according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the present invention are shown. This invention may, however, be embodied in 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 be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thickness of layers and regions are exaggerated for clarity. Like numbers refer to like elements throughout the specification.
FIG. 3 is a cross-sectional view illustrating a multi-chip module according to an embodiment of the present invention.
Referring to FIG. 3 , a bottom chip 55 and a top chip 63 are sequentially stacked on a substrate 51 . The substrate 51 includes a plurality of interconnections formed on a surface of the substrate 51 . The substrate 51 may be, for example, a lead frame or a printed circuit board. The interconnections are composed of a first group of interconnections 51 a and a second group of interconnections 51 b . The bottom chip 55 has bonding pads 57 formed on the periphery or edges of its front surface. Also, the top chip 63 has bonding pads 65 formed on the edges of its front surface. In particular, the top chip 63 has a chip substrate 63 a and an insulating film 63 b attached to its backside surface. In addition, the insulating film 63 b can cover the backside surface of the chip substrate 63 a . The insulating film 63 b has a tape-shaped configuration or a sheet-shaped configuration.
An adhesive 53 may be interposed between the bottom chip 55 and the substrate 51 . Thus, the bottom chip 55 is fixed to the substrate 51 by the adhesive 53 . Also, an insulator 61 is interposed between the bottom chip 55 and the top chip 63 . The insulator 61 may have a smaller width than the chips 55 and 63 so that the pads 57 of the bottom chip 55 are exposed. The top chip 63 may have the same dimensions as the bottom chip 55 and fully cover the bottom chip 55 , as shown in FIG. 3 . Alternatively, the top chip 63 may have a greater planar area than the bottom chip 55 . In other words, the top chip 63 may be wider and/or longer than the bottom chip 55 .
The pads 57 of the bottom chip 55 are electrically connected to the first group of interconnections 51 a through a first group of bonding wires 59 . In this case, the chip substrate 63 a of the top chip 63 is not in direct contact with the first group of bonding wires 59 because of the presence of the insulating film 63 b , even though the insulator 61 is very thin. Therefore, the total height of the stacked chips 55 and 63 can be reduced as compared to the conventional MCMs shown in FIGS. 1 and 2 .
Further, conductive bumps 57 a may be additionally formed on the pads 57 of the bottom chip 55 . In this case, the first group of bonding wires 59 are electrically connected to the pads 57 through the bumps 57 a and are preferably formed using a bump reverse bonding technique, which is well known in the art. If the first group of bonding wires 59 are formed using the bump reverse bonding technique, the height from a top surface of the pads 57 to the highest portion of the bonding wires 59 can be remarkably reduced. This allows the insulator 61 to become thinner without any contact between the bonding wires 59 and the insulating film 63 b . Accordingly, reliability of a multi-chip module can be improved.
The pads 65 of the top chip 63 are electrically connected to the second group of interconnections 51 b through a second group of bonding wires 67 . Bumps 65 a may be additionally stacked on the pads 65 of the top chip 63 . In this case, the second group of bonding wires 67 are electrically connected to the pads 65 through the bumps 65 a . The second group of bonding wires 67 may be formed using the above-mentioned bump reverse bonding technique. The stacked chips 55 and 63 as well as the bonding wires 59 and 67 are sealed with an epoxy molding compound (EMC) 69 .
A method of fabricating a multi-chip module according to an embodiment of the present invention will now be described with reference to FIGS. 4 to 6 .
Referring to FIG. 4 , a substrate 51 is first provided that has a plurality of interconnections formed on a surface thereof. Also, the interconnections include a first group of interconnections 51 a and a second group of interconnections 51 b . A bottom chip 55 is mounted on the substrate 51 . Adhesive material 53 may be additionally put on the surface of the substrate 51 before mounting the bottom chip 55 on the substrate 51 . Accordingly, the bottom chip 55 can be fixed to the substrate 51 by the adhesive 53 . The bottom chip 55 has bonding pads 57 formed on the edges of its front surface (top surface).
Referring to FIG. 5 , a first group of bonding wires 59 are formed to connect the pads 57 a to the first group of interconnections 51 a . The bonding wires 59 may be formed of gold wires. Conductive bumps 57 a may be additionally formed on the pads 57 before forming the first group of bonding wires 59 . In this case, the first bonding wires 59 are electrically connected to the pads 57 through the bumps 57 a and are preferably formed using a bump reverse bonding technique. If the first group of bonding wires 59 are formed using the bump reverse bonding technique, the distance from a top surface of the pads 57 to the highest portion of the bonding wires 59 can be significantly reduced. An insulator 61 is then formed on the bottom chip 55 . Preferably, the insulator 61 has a narrower width than the bottom chip, thereby still exposing or uncovering the pads 57 and the bonding wires 59 . In other words, the insulator 61 can be preferably formed to fit on a predetermined region on the bottom chip where it will be surrounded by the pads 57 .
Referring to FIG. 6 , a top chip 63 is mounted on the insulator 61 . The top chip 63 includes a chip substrate 63 a and a thin insulating film 63 b attached to its backside surface (bottom surface). Thus, the insulating film 63 b can cover the entire backside surface of the chip substrate 63 a . Accordingly, the insulating film 63 b can be in contact with the insulator 61 . The top chip also has bonding pads 65 formed on edges of its front surface (top surface) of the chip substrate 63 a.
The top chip 63 may have the same dimensions as the bottom chip 55 and may be mounted to fully cover the bottom chip 55 , as shown in FIG. 6 . Alternatively, the top chip 63 may have a greater planar area than the bottom chip 55 . In other words, the top chip 63 may be wider and/or longer than the bottom chip 55 . In any case, the edges of the top chip 63 are located above the ends of the first group of bonding wires 59 where they are connected to the pads 57 of the bottom chip. Even if the bonding wires are touching the top chip 63 , the chip substrate 63 a is not in direct contact with the bonding wires 59 because of the presence of the insulating film 63 b . This results in allowing the thickness of the insulator 61 to be drastically reduced. Accordingly, the total height of the stacked chips 55 and 63 are greatly reduced as compared to the conventional multi-chip module shown in FIGS. 1 and 2 .
Further, in the event that the first group of bonding wires 59 are formed using the bump reverse bonding technique as described above, the insulating film 63 b can be altogether prevented from being in contact with the bonding wires 59 . In other words, the thickness of the insulator 61 can be even further reduced without any contact between the bonding wires 59 and the insulating film 63 b . As a result, a highly reliable and thin multi-chip module is realizable.
Subsequently, a second group of bonding wires 67 are formed to connect the pads 65 of the top chip 63 to the second group of interconnections 51 b . The second group of bonding wires can be formed using a conventional wire bonding technique (See the dashed line 67 a in FIG. 6 ). Alternatively, bumps 65 a may be formed on the pads 65 prior to formation of the second group of bonding wires 67 . In this case, the second group of bonding wires 67 (the solid line in FIG. 6 ) may be formed using the bump reverse bonding technique and electrically connect to the pads 65 through the bumps 65 a.
Though not shown in the drawing of FIG. 6 , epoxy molding compound (refer to 69 of FIG. 3 ) is then formed to seal the stacked chips 55 and 63 as well as the bonding wires 59 and 67 (or 67 a ).
According to the embodiments described above, the thickness of an insulator interposed between stacked chips can be reduced by employing a thin insulating film that covers the backside surface of the chip substrate of the top chip. Therefore, a reliable and thin multi-chip module can be realized. | Provided herein are multi-chip modules (MCMs) having bonding wires and fabrication methods thereof. The multi-chip module includes a substrate and a plurality of chips sequentially stacked. At least one top chip, stacked above a lowest chip, has an insulating film that covers the backside thereof. Also, each of the stacked chips has bonding pads formed on the periphery or edges of its upper surface. At least one insulator is interposed between the stacked chips. The insulator exposes the pads on the underlying chip. The pads of the respective chips are connected to a set of interconnections, which are disposed on the substrate. This configuration of stacked chips enables the overall height of the memory module to be reduced because the insulating film prevents the bonding wires from contacting the substrate of the top chips. | 7 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an apparatus for inter-connecting optical devices and, more particularly, to a connector for terminating an optical fiber.
[0002] Optical fiber connectors are an essential part of substantially any optical fiber based communication system. For instance, such connectors may be used to join segments of fiber into longer lengths, to connect fiber to active devices such as transceivers, detectors and repeaters, or to connect fiber to passive devices such as switches and attenuators. The central function of an optical fiber connector is to maintain or position two optical fiber ends such that the core of one fiber is axially aligned with the core of the other fiber. Consequently, the light from one fiber is coupled to the other fiber or transferred between the fibers as efficiently as possible. This is a particularly challenging task because the light-carrying region or core of an optical fiber is quite small. In single mode optical fibers, the core diameter is about 9 microns. In multi-mode fibers, the core can be as large as 62.5 to 100 microns, and hence alignment is less critical. However, precision alignment is still a necessary feature to effectively interconnect the optical fibers.
[0003] Another function of the optical fiber connector is to provide mechanical stability to and protection for the optical junction in its working environment. Achieving low insertion loss in coupling two fibers is generally a function of the alignment of the fiber ends, the width of the gap between the ends, and the optical surface condition of either or both ends. Stability and junction protection is generally a function of connector design (e.g., minimization of the different thermal expansion and mechanical movement effects). Precision alignment of the optical fiber is typically accomplished within the design of the optical terminus assembly. The typical optical terminus assembly utilizes a method of retention of the terminus within the connector(s) integrated within it and a method of holding and aligning the optical fiber. To align the optical fiber, a terminus typically includes a small cylinder of metal or ceramic at one end commonly referred to as a “ferrule.” The ferrule has a high precision hole passing along it centerline and glass or plastic optical fiber can be installed into the hole within the ferrule using mechanical, adhesive or other retention methods. The primary operational sections of an optical terminus are the support structure around the ferrule and the mechanism (typically a spring) used to create a force to push the ferrule into an opposing ferrule of a mating optical connector.
[0004] In a connection between a pair of optical fibers, a pair of ferrules is butted together in an end to end manner and light travels from one to the other along their common central axis. In this conventional optical connection, it is highly desirable for the cores of the glass fibers to be precisely aligned in order to minimize the loss of light (such loss being referred to as insertion loss) caused by the connection. As one might expect, it is presently impossible to make a perfect connection. Manufacturing tolerances may approach “zero” but practical considerations such as cost, and the fact that slight misalignment is tolerable, suggest that perfection is unnecessary although stability across the operating environment of the fiber joint is critical.
[0005] Historically, due to manufacturing costs and design features, optical termini have tended to be manufactured as an assembly of loose components. In high performance connectors intended for single mode application, there exists a specific need to tune out the eccentricity of assemblies and such tuning has been achieved by the interaction between the terminus or ferrule support structure and the connector housing. This is an undesirable effect as the housing becomes an integral element in tuning and if the terminus is removed from the housing (such as for cleaning or replacement), the tuning is in effect lost.
[0006] Optical terminus assembly tuning is used to reduce the random position of the optical fiber within an optical connector. The randomness of this positioning may be in the order of fractions of microns to several microns. However, when consideration is taken of single mode optical fiber with an optical waveguide of only 8-9 microns in diameter, it can be seen how optical insertion loss can be dramatically impacted if control of the placement of the optical core is not maintained. Fiber eccentricity compensation is currently most commonly found on single channel “LC” style connectors. Compensation is attained using a faceted structure (such as a square or hexagon) to register on the front end of the ferrule support structure. The support structure engages an appropriate complementary pattern within the LC connector body and retains positioning by engaging the LC body. Thus tuning or fiber eccentricity compensation is only retained as the ferrule and its support is retained within the connector body. Once removed it is not possible to determine the exact positional relationship between the fiber holding structure and the connector body.
[0007] Recognizing the engineering challenge posed by the alignment of two very small optical fiber cores, it is desirable to provide termini that are smaller, less expensive, and yet more convenient for customers to manipulate. One of the key features associated with the design of termini is the system for retaining the termini in a connector. The retention feature affects the ability of the terminus to be engaged into a connector system and retained within the connector system during mating of the two connector halves. The retention system must enable users of the optical terminus system and its associated connector system the ability to remove the optical termini individually for service, repair, inspection or other reasons. Existing optical termini systems are typically utilized in military connector systems and some designs incorporate anti-rotation features but none include an operative retention system and tuning capability as an integral part of the terminus.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide a terminus retention system that removes complexity from the connector system and enables users to quickly service connectors, yet retain the tuning of a terminus. As such, a connector is disclosed for terminating an optical fiber including a fiber holding structure for maintaining eccentricity compensation and having an end face in which an associated fiber is terminated within the holding structure and including an axial passageway which terminates in the end face and which is adapted to receive an end portion of the associated optical fiber. A connector housing has internal surfaces that define a cavity to accept the fiber-holding structure and includes first and second openings extending into the cavity and being positioned at opposite ends of the housing. The first opening is configured to receive an optical fiber and the second opening is configured to enable the end face of the holding structure to protrude through the opening. A latch is provided integral to the fiber holding structure to secure the fiber holding structure within an associated cavity. To preclude unintended decoupling therebetween, the latch includes a protrusion positioned on one or more surfaces of a sliding collar integral to the fiber holding structure. The latch is configured to engage the cavity structure by having the protrusion sweep an arc beneath an upper surface of the cavity. When the latch protrusion is swept through the arc, it is held beneath the rear face of the cavity by spring pressure created by compression of a primarily helical spring coaxially located along the fiber holding structure longitudinal axis.
[0009] In the preferred embodiment, the spring member interacts between two surfaces within the fiber-holding structure. The fiber holding structure also provides a keying structure to engage the housing and likewise urge an end face or ferrule through the second opening in the housing.
[0010] The terminus is a cylindrical fiber-holding structure with a ferrule that includes the end face in which the associated fiber is terminated and an axial passageway which terminates in the end face. This passageway is adapted to receive an uncoated end portion of the associated fiber. A base member holds an end portion of the ferrule within the terminus assembly and includes an axial passageway which is collinear with the axial passageway of the ferrule. A shoulder may also be provided to engage a spring of the terminus assembly. A rear portion of the base member provides a multi-positional eccentricity index feature, such as a hexagonal section. A sliding collar which has a shoulder to engage a spring, an axial pass way in which the base member assembly is positioned and an external index “key” formed by one or more protrusions. A spring member is provided to push the sliding collar towards the rear of the base member. In one embodiment, the cylindrical ferrule has a diameter of about 1.25 millimeters.
[0011] The cylindrical plug of the present invention includes a tube whose outer cylinder surface has a circular cross section and whose axial passageway is substantially concentric with the outer cylinder surface and wherein the tube is made from ceramic or metallic materials. The fiber-holding structure is adapted to be held within the housing in a singular stable angular position such that the angular position of the fiber-holding structure with respect to the housing is constant. In addition, the fiber-holding structure sliding collar index key allows the entire fiber-holding structure to be removed from the connector housing yet maintain its singular stable angular position when returned to the connector housing. The connector housing includes first and second interconnecting housing members which each include an internal cavity for receiving the fiber-carrying structure. The second interconnecting member is generally cylindrical in shape so as to mate with the first interconnecting member. The first and second interconnecting members combine to form a structure that substantially encloses the fiber-holding structure. The first and second interconnecting members are made from a metallic, plastic or ceramic material and are secured together using a positive locking device such as a threaded collar, a coupling screw or external physical clamp.
[0012] An optical cable and a connector are also disclosed in which the optical cable includes a glass fiber enclosed within a plastic buffer material and the connector includes a fiber-holding structure with an axial passageway which receives the optical fiber and which terminates in a planar end face that is perpendicular to the passageway. A housing has internal surfaces that define a cavity and surround the fiber-holding structure as well as a first opening at the back end of the housing which receives the optical cable and a second opening at the front end of the housing through which the end face of the fiber-holding structure protrudes. The openings extend into the cavity and are positioned at opposite ends of the housing. The housing captures the fiber holding structure in a manner such that eccentricity is confined to a unique, known position. A manually operated latch for securing the fiber holding structure to the associated receptacle is also provided to preclude unintended decoupling therebetween. The latch is positioned on a one or more side surfaces of the sliding collar section integrated within the fiber holding structure. The latch includes a spring element contained within the fiber holding structure. The fiber-holding structure includes an annular spring that interacts with two flanges or shoulders within the fiber-holding structure. One of the shoulders is free to move relative to the other along the primary axis of the fiber-holding structure and engages the housing thus urging the end face of the fiber-holding structure through the second opening in the housing.
[0013] A connector for terminating an optical fiber includes a fiber-holding structure that terminates in an end face and is adapted to receive an end portion of the optical fiber. A housing includes a plurality of internal surfaces that define a cavity and surround the fiber-holding structure, a first opening for receiving an optical fiber holding structure/optical fiber and a second opening for enabling the end face of the fiber-holding structure to protrude therethrough. The openings extend into the cavity and are positioned at opposite ends of an axial passageway through the housing. The fiber-holding structure includes a compression spring which presses two shoulders or flanges on the fiber holding structure. The flanges are free to move axially relative to one another to urge the end face of the fiber-holding structure through the second opening in the housing.
[0014] An optical fiber connector is disclosed for effecting optical end-to-end coupling between two optical fibers, each of which terminates in a ferrule having a precision cylindrical outside surface. One end of each ferrule is held within an opening in a base member. The base member is generally cylindrical and has a flange which is disposed around the circumference of the base member and interacts with one end of an annular spring which is also disposed around the base member. The ferrule, base member and spring are joined to a secondary member that includes a hexagonal or other even sided geometric shaped indexing feature. A sliding member including a latch protrusion feature that engages the secondary member to permit indexing of the hexagonal or other even sided geometric shaped indexing feature and further engages a connector body housing. This engagement is accomplished with one or more unique indexing keys that extend approximately perpendicular to the longitudinal axis of the siding member and engage an appropriate slot in the connector body housing.
[0015] An optical fiber terminus body has a helical spring trapped between front shoulder on a main inner body and a rear shoulder created by a thin flange on a sliding collar. The sliding collar is likewise trapped between the rear of the spring and a rear shoulder on the main inner body. Typically, the inner body is formed using two components that are pressed, bonded, welded or otherwise assembled. The collar has an alignment ring on it to retain precise alignment of the terminus within a stepped cylindrical bore. The collar also has a protrusion that enables keying and positive positioning of the terminus assembly within a stepped cylindrical bore when the bore has an appropriate slot formed in it or a slot that is created with a secondary piece. The slot is configured with a cut that extends along an arc around the axis of the bore so that the protrusion can act as a retainer mechanism for the terminus assembly in the cylindrical bore. This is accomplished by inserting the terminus into the bore until the front edge of the section having the front spring retention shoulder engages a step in the bore. This presents further penetration of the terminus assembly through the stepped bore. At that time, the sliding collar begins to move forward along the main inner body. The protrusion on the collar moves through the slot along the side of the bore and the spring is compressed. As the protrusion on the collar reaches the end of the slot in the bore, it can be rotated in an undercut arc in the bore. When rotated to the end of the arc, the protrusion cannot pass back upward along the axis of the bore. Hence, there remains compression of the spring and the entire assembly is captured within the bore by the spring pressure between the front shoulder on the main inner body and the sliding collar that has engaged the cylindrical bore. To facilitate tuning of the terminus, a hexagonal or other faceted shaped section integral to the main terminus body is provided at the rear of the main terminus body and engages the sliding collar. The hexagonal or other faceted shaped section is included to allow tuning or minimization of eccentricity of the internal bore relative to a mating terminus of the same type. Tuning is accomplished by determining a desired position for the offset in the bore centerline in the main inner body relative to the sliding collar. If a hexagonal tuning section is used, one of six positions is available. The sliding collar engages one of the available tuning sections on the main inner bodies. These and other objects, features and advantages of the present invention will be clearly understood through a consideration of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Other objects and advantages of the present invention will be understood from the following description according to one preferred embodiment of the present invention which is shown in accompanying drawings in which:
[0017] FIG. 1 is a perspective view of one embodiment of an optical fiber terminus in accordance with the principles of the present invention;
[0018] FIG. 2 is an exploded perspective view of the optical fiber terminus of FIG. 1 ;
[0019] FIG. 3 is a side elevational view of the optical fiber terminus of FIG. 1 ;
[0020] FIG. 4 is a perspective view of one embodiment of an optical fiber connector in accordance with the principles of the present invention including a plurality of optical fiber termini of FIG. 1 mounted therein;
[0021] FIG. 5 is a partially exploded perspective view of the optical fiber connector of FIG. 4 from a different orientation with a central portion of the connector housing removed from an outer shell of the connector;
[0022] FIG. 6 is an exploded perspective view of the central portion of the connector housing together with a plurality of optical fiber termini;
[0023] FIGS. 7A-7D are perspective views of the optical fiber terminus showing a portion of the sequence of tuning the optical fiber terminus by axially moving and rotating the sliding collar relative to the inner main body; and
[0024] FIGS. 8A-8D are perspective views, partially in section, of the optical fiber terminus and central portion of the connector housing showing the sequence of insertion of the optical fiber terminus into the housing and locking of the terminus therein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] In accordance with one embodiment of the present invention and referring first to FIGS. 1 and 4 , an optical fiber support assembly or terminus 10 and an optical fiber connector 60 that includes a plurality of termini, as well as a method of assembly, are disclosed. The terminus includes three main components, inner main body or member 12 , a sliding collar or outer member 14 with protrusion boss or tab 16 extending radially therefrom and substantially helical spring or biasing member 18 . The inner main body is typically an assembly of three components ( FIG. 2 ) a ferrule 20 (typically made of ceramic or metal), a forward section or body 22 that is joined to the ferrule with an adhesive or by a press-fit and a rear section or body 24 that is assembled with forward section 22 and captures the sliding collar and helical spring 18 therebetween. As described in more detail below, sliding collar 16 is indexable through the interaction between registration structure integral to the collar and indexing structure integral to the rear of inner main body. The sliding collar is further indexed relative to the connector assembly by the interaction of features included in the connector body and the protrusion on the sliding collar.
[0026] As described above, the terminus 10 has a ferrule 20 attached to the inner main body to position an optical fiber along the longitudinal centerline or axis “A” of the terminus assembly. The terminus has an opening or bore 26 therein for receiving an end of an optical fiber. The inner main body 12 has a shaft portion 28 ( FIGS. 1 and 3 ) formed by the combination of forward section 22 and rear section 24 about which the spring 18 can be positioned and aligned. A forward shoulder 30 on main body 12 forms a front abutment that abuts a front end 32 of the spring, and a shaft recess forming a shoulder. Sliding collar 14 is also installed onto the shaft portion 28 of the main inner body 12 adjacent spring 18 .
[0027] Sliding collar forms the rear abutment 34 that abuts the rear end 36 of the spring. An engagement section 38 is formed at the rear of collar 14 with opposing arms 42 having inwardly facing flat surfaces 44 . The flat surfaces 44 of the arms engage a multi-faceted (typically hexagon) indexing section 40 on the rearward end of the inner main body. Opposing arms 42 engage opposite sides of the hexagonal indexing section 40 to prevent rotation of the collar 14 relative to the inner main body 12 and further enable selection of multiple orientations of the inner main body relative to the collar 14 and the protrusion boss 16 projecting therefrom. The main terminus body 12 has a rear shoulder 46 that prevents the collar 16 and spring 18 from sliding off the shaft 28 and provides a pre-load compression of the spring when assembled. The main terminus body 12 is typically a two piece component that is either press fit together, bonded together, welded together or affixed together into a single piece using another method of securement. The assembly of ferrule 20 , main terminus body 12 , spring 18 and sliding collar 16 is commonly referred to as a terminus assembly.
[0028] Referring to FIGS. 4-6 , the terminus assembly 10 must be retained within a connector housing or body 62 in order to form a single or multiple optical pathways interconnect system. An interconnect system is typically formed with a plug connector (not shown) and a mating receptacle connector 60 . During mating, opposing optical termini are brought into direct end face contact with one another and the optical fiber (shown in phantom lines in FIG. 1 ) positioned within each terminus are optically coupled together. When mating of the optical termini is properly implemented, a very low optical loss interconnection is formed. When utilizing termini of the present invention, arrays of very dense, very high performance optical interconnect solutions can be formed.
[0029] The terminus assembly 10 is retained within connector housing 62 through the interaction between the protrusion boss 16 on sliding collar 14 and structure of the connector housing. Retention is achieved when the terminus assembly 12 is installed into a principally cylindrical bore or terminus cavity 64 within a connector housing or body 62 . In the preferred embodiment, the connector housing is formed from two components, a front housing member 66 and a rear housing member 68 . The front and rear housing members are made of metal, plastic or ceramic and are held together by a positive locking device such as a coupling screw 69 although other devices such as a threaded collar or an external physical clamp could be used.
[0030] The terminus cavity has two or more primary diameters. A smaller, forward diameter 70 generally approximates the diameter of the ferrule 20 and is smaller than the diameter of the leading section 52 of forward section 22 into which the ferrule is pressed. The largest diameter 72 in the terminus cavity is adjacent the rear of the connector and this diameter is slightly larger than the diameter of the main body 48 of the sliding collar. In the embodiment shown, the sliding collar has a full periphery precision shoulder 50 that interacts with the rear bore diameter 72 to provide very precise alignment of the sliding collar 14 with respect to the rear bore diameter of the terminus cavity. This is desirable to maintain axial alignment of the entire optical termini assembly 10 relative to the axis of the terminus cavity. Other methods of precision alignment may be feasible such as multiple raised sections or a precision machined main body for the sliding collar.
[0031] Referring to FIG. 6 , the rear opening 74 of the bore in the terminus cavity 64 has a slot 76 extending from a rear face 78 of the housing along an edge of the bore a relatively short distance into the terminus cavity. An arcuate retention slot or recess 80 extends along an arc from the slot 76 with the arc being formed about the central axis “B” of the cavity and principally perpendicular to the slot. This arcuate recess forms a turning section adjacent the slot that extends generally at a right angle to axis B. A small recess 82 is added at the end of the arc in a direction parallel to the central axis of the cavity for receiving the protrusion boss 16 of sliding collar 14 to secure the terminus assembly 10 in the housing as described below.
[0032] During assembly, the terminus assembly is retained within the housing by positioning the terminus assembly 10 at the rear of the terminus cavity 64 with protrusion boss 16 and slot 76 aligned as shown in FIG. 8A and moving terminus assembly 10 along the central axis B of the cavity 64 by gripping or engaging the sliding collar 14 with an appropriate tool (not shown). This forward movement continues until the front or forward edge or shoulder 52 of the inner terminus body engages the forward wall 84 of the smaller diameter bore 70 in the terminus cavity. The ferrule 20 will be extending through front face 86 of the terminus cavity bore and positions the terminus assembly 10 to substantially a central location along the terminus cavity 64 so that the central axis B of the cavity and the central axis A of the terminus assembly coincide. When front edge 52 of the terminus inner body 12 engages the front face in the terminus cavity, forward movement of inner body 12 is stopped. By continuing to apply force to sliding collar 14 , collar 14 continues to move forward relative to terminus inner body 12 and, thus, also compressing spring 18 that is an integral part of terminus assembly 10 . ( FIG. 8B ) The protrusion boss 16 on the terminus collar 14 is aligned with the slot in the wall of the terminus cavity and passes along it until it reaches the end of the slot. Preferably, the opposing arms 42 of collar 14 and hexagonal indexing section 40 are dimensioned so that arms 42 still engage indexing section 40 when protrusion boss 16 reaches the end of the terminus cavity slot. Through such structure, the tuning of terminus assembly 10 is not affected or changed during insertion of the assembly into the terminus cavity.
[0033] Referring to FIG. 8C , once protrusion boss 16 abuts the end of slot 76 , the collar 14 and entire terminus assembly 10 are rotated together about the axis B of the terminus cavity with protrusion boss 16 traveling through arcuate retention slot 80 until the protrusion boss 16 engages the end wall 88 of the arcuate retention slot. As force is released from the collar 14 such as by a technician installing the terminus assembly, spring 18 provides a force that pushes collar 14 axially rearward so that protrusion boss 16 enters recess 82 at the end of the arcuate retention slot 80 to retain the protrusion boss therein ( FIG. 8D ). This spring force maintains the terminus assembly 10 both radially and axially in the terminus cavity bore 64 and hence within the connector assembly 60 . In other words, the orientation of the terminus assembly is retained in a predetermined position since the position of collar 14 is determined by the location of the arcuate retention slot, and the terminus inner body 12 is fixed relative to collar 14 by the indexing features, as described above. In industrial vernacular, the terminus retention system described above is known as a “quarter turn” fastener, although in the present embodiment, the quarter turn fastener is modified in that only a single protrusion boss 16 is used. In addition, the single protrusion boss 16 is what enables tuning of the optical connector system.
[0034] The present invention incorporates an optical ferrule holding structure 10 , termed the optical terminus assembly and a support structure, termed the connector. The connector has an optical terminus cavity for each channel in a single or multiple channel connector system. The cavity has a “key” feature that identifies positional location for proper tuning by aligning the protrusion boss 16 feature on the sliding collar 14 of opposing termini to be in-line. In this manner, by establishing eccentricity compensation relative to the protrusion boss, the relative eccentricity of two mating ferrules will be minimized and the resulting optical loss likewise minimized. Further, according to the present invention, by properly positioning the boss and retaining it within the connector body, the entire assembly can retain its eccentricity compensation even when the fiber support structure or terminus 10 is removed from the connector body.
[0035] Since retaining eccentricity compensation is a key feature of the disclosed invention, it is important to understand the eccentricity issues. Alignment variations between a pair of interconnected ferrules 20 are principally attributable to the parameter known as “eccentricity” of the optical fiber core with respect to the ferrule. Eccentricity is defined as the distance between the longitudinal centroidal axis of the ferrule at an end face of the ferrule and the centroidal axis of the optical fiber core held within the passageway of the ferrule. Generally, the passageway is not exactly concentric with the outer cylindrical surface that is the reference surface. Also, the optical fiber may not be exactly centered within the ferrule passageway and the fiber core may not be exactly concentric with the outer surface of the fiber. Hence, the eccentricity is comprised of the eccentricity of the optical fiber within the ferrule passageway and the eccentricity of the passageway within the ferrule.
[0036] If one could view the end portion of a “lit” optical fiber, what would be seen is a circle with a dot of light somewhat displaced from the exact center of the circle. Eccentricity can be understood as a two-dimensional vector having magnitude and direction components. The “magnitude component” of the eccentricity vector is the straight line distance between the center of the circle and the dot of light, while the “direction component” of the eccentricity vector is the angle made by that straight line with respect to the X-axis of a 2-dimensional Cartesian coordinate system whose origin is at the center of the circle. It is noted that ferrules used in conventional optical connectors (i.e., ST, SC and FC) have a 2.5 mm diameter while the ferrule disclosed in a preferred embodiment of the present invention has a diameter of 1.25 mm as utilized by the LC connection system. With the use of the smaller ferrule, the magnitude component of the eccentricity vector is proportionally reduced and thus precision is improved.
[0037] Rotating one of two interconnected ferrules typically changes the relative position of the fibers held within their passageways because of the eccentricity of the optical fiber cores with respect to the ferrules. Because it is very difficult to control the eccentricity of the optical fiber core in the ferrule in which it is terminated, it is difficult to achieve desired losses of 0.1 dB or less in single mode fibers without maintaining close tolerances so that the opposed cores are aligned to within about 0.7 microns. This scale of precision increases the manufacturing cost. If the total eccentricities of the two optical fiber ends to be joined are identical, or at least very nearly so, then a low-loss connection can be achieved by merely rotating, within the collar 14 , one ferrule 20 with respect to the other, until maximum coupling is observed (minimum insertion loss).
[0038] Referring to FIGS. 7A-7D , the present invention enables fiber eccentricity to be compensated through the use of an indexing slot 44 between arms 42 in the terminus assembly 10 . The terminus assembly 10 is designed such that it can be configured with one of six (hex) rotational positions relative to a master indexing key (protrusion boss 16 on the sliding collar 14 ). More or fewer registration features may be used. The key is an integral part of the sliding collar and although the preferred embodiment uses only one key, one or more keys may be used so long as unique orientation identification is retained.
[0039] Such a design enables the terminus assembly 10 to be installed in a connector body in one of six rotational positions (0 degrees, 60 degrees, 120 degrees, 180 degrees, 240 degrees, 300 degrees). The particular position selected is determined during fabrication of the connector by measuring fiber eccentricity, linearly moving the inner main body 12 relative to collar 14 along axis A from a position ( FIG. 7A ) in which relative rotation between inner main body 12 and collar 14 is prevented by engagement between indexing slot 44 and indexing section 40 a sufficient distance (as shown n FIG. 7B ) to permit relative rotation between inner main body 12 and collar 14 . The inner main body 12 is then rotated relative to collar 14 ( FIG. 7C ) by an amount based on optical power loss minimization measurement such that the arms 42 of the indexing slot 44 are aligned with indexing section 40 . Once in the desired rotational position, force is removed from collar 14 to permit spring 18 to bias collar away from ferrule 20 such that indexing slot engages indexing section 40 to prevent relative movement between the inner main body 12 and sliding collar 14 .
[0040] The final requirement for a high optical performance connector is to align the terminus assembly to a specific location when installed into the connector body. As has been described above, this is accomplished by using a slot in the terminus cavity. When mated connectors are brought together, their structures both provide for the retention of orientation relative to the opposing optical terminus assemblies.
[0041] 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, and consequently, it is intended that the claims be interpreted to cover such modifications and equivalents. The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings. | An optical fiber connector includes a connector housing having first and second generally parallel, spaced apart first and second faces and at least one generally cylindrical receptacle for removably receiving an optical fiber terminus therein. An optical fiber terminus is located within the receptacle and includes an elongated body with a passage along a central axis for receiving a portion of an optical fiber cable therethrough. The body further includes an indexing section, and a ferrule secured to the body and having an end portion of said optical fiber cable therein. A collar is positioned on the elongated body and has an engagement section for engaging the indexing section. The collar is movable along the axis between first and second operative positions. In the first operative position relative rotational movement between the collar and the body is prevented and in the second operative position the collar may rotate relative to the body. A biasing member is provided to bias the collar towards the first operative position. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to convenient, user operable, self-storing basketball goal systems.
BACKGROUND OF THE INVENTION
[0002] Basketball goals in residential areas are often an eyesore, especially after a few years of weather deterioration. In some neighborhoods, local ordinances have restricted the location of such devices or have outright banned permanent erection of basketball goals. To attempt to answer the perceived need, the prior art reveals several inventions relating to portable basketball goals.
[0003] Most existing basketball systems are semi-permanent when assembled, or are only partially diassembleable. Such systems include, as examples, US Patent Publication Number 2004/0157688 of Schroeder et al, U.S. Pat. No. 5,100,132 of Anderson, U.S. Pat. No. 5,255,909 of Wendell, U.S. Pat. No. 5,628,508 of Koole, U.S. Pat. No. 5,730,668 of Hege et al, U.S. Pat. No. 5,772,167, also of Koole, U.S. Pat. No. 5,800,294 of Naecker, Jr., U.S. Pat. No. 5,902,197 of Davis et al, U.S. Pat. No. 5,947,847 of van Nimwegen et al, U.S. Pat. No. 5,983,602 of Allen et al, U.S. Pat. No. 6,783,472 B1 of Stanford et al, U.S. Pat. No. 6,866,696 B2 of Steed et al and U.S. Pat. No. 6,881,163 B2 of Schroeder et al.
[0004] One basketball backboard and net set (U.S. Pat. No. 3,716,234 of Lancelotti) is disassembleable into a box, but all the parts have to be taken apart by loosening rigid nuts and bolts, which of curse are subject to strength requirements for removal and become tighter as time goes on due to the effects of outdoor weather.
[0005] None offer the combined features of self-storage at the playing site, high goal stability with desirable offset between post and backboard, and ease of erection or disassembly without the use of tools.
OBJECTS OF THE INVENTION
[0006] It is therefore an object of the present invention to provide a convenient, user operable, self-storing basketball goal system.
[0007] Other objects which become apparent from the following description of the present invention.
SUMMARY OF THE INVENTION
[0008] In keeping with these objects and others which may become apparent, the self-storing basketball goal system of this invention provides a watertight storage compartment in a foundation box. The foundation box is preferably installed within the ground so that the post assembly attaches to a top cover thereof flush with the ground.
[0009] However, alternatively, it can be a remote storage container where the post assembly attaches to one or more keyways in the playing surface, such as a gymnasium floor, a driveway or a patio. When the foundation box is installed within the ground, it is accessible via a lid that is flush mounted with the ground surface. When not in use, all three subassemblies (rim, backboard, and post) are stored within the compartment. When in use, the post is assembled and locked to the lid of the storage compartment; the rim and backboard are attached to the post, and the entire task is completed in short time without the use of any tools. The post assembly is very robust, and its cantilever removes the post from the playing area providing safety for aggressive fast play. The goal stability is much higher and not subject to tip, like other portable goals. Existing portable goals are also too heavy and cumbersome to move, and too big to store. The rim height can be easily adjusted to accommodate shorter players. Auxiliary mounting plates can be installed to provide alternate playing areas to receive the goal system remote from its storage area. Three small floor plates with female socket features matching those on the auxiliary mounting plates can be mounted flush on a gym floor at the proper spacing to receive the post assembly of this basketball goal system for portable indoor use in a gym area.
[0010] The foundation box with storage compartment is installed in an excavated area below grade, or is a remote storage container. When installed in the ground, this foundation for the goal system is installed without the use of concrete which makes it relatively easy to remove and reinstall in another location. Also, the installation area is not permanently altered, be it lawn area or beach sand. In some types of rocky soil material, it is adequate to just bury the foundation box to achieve sufficient stability. In sandy areas or in lighter soil, a ballast, such as a ballast box, ballast plate or other ballasted retaining area, is first installed and filled with heavy ballast such as rocks. The ballast box is installed and carefully leveled at a depth such that the foundation box which is then bolted to its top rim will have its lid flush with the ground surface. The ballast box has a bottom panel that can be removed during installation. The person performing the excavation can actually stand in a hole below the ballast box through this panel hole to more easily perform the leveling operation. After leveling, the foot hole is back-filled, and the bottom panel is bolted back in place before the ballast is introduced.
[0011] The post assembly is articulated and telescoping to fit into a relatively small storage compartment. It is preferably constructed of aluminum square tubing of the order of four inches square. By “tubing” it is noted that while the preferably crossection of the tubing is square, it can have any geometric crossection, such as circular, triangular, rectangular or otherwise.
[0012] The main post is foldable and/or telescopic in sections, so that it fits with the backboard and removable hoop rim within the foundation box. The main post is foldable and optionally also telescopic in a plurality of sections, preferably in four sections. A bottom length telescopes into an equal length section which is hinged to a similar upper section with its own telescoping section within; the telescoping upper section is then hinged to a shorter backboard attachment section. The telescoping members are captive within the outer members and preferably telescope freely on internal low friction sleeves (such as Teflon TM). All sections of the post assembly are preferably pre-attached; another part is a sleeve which rides on the outer lower section (again with low friction internal sleeve). This sleeve collar carries a plurality of support struts, preferably two struts, which attach to the playing surface, such as to the lid of the storage compartment as does the bottom distal end of the lower telescoping section which attaches first via a rotary motion into a triple keyway. The two struts are preferably locked into the base by straightening a lock, such as a folding locking horizontal strut which action forces the strut bottoms laterally within their straight keyways. Note that the lid of the storage box is sturdily locked shut via a lock, such as a pair of cam locks that are then prevented from opening by interference from the two struts locked into their respective keyways adjacent to the lock handles.
[0013] The backboard attaches to the attachment post via a fastener, such as a hinged member on a bracket which is locked around the post via a fastener, such as a toggle latch clamp. The rim attaches to the same post in the same manner via a fastener, such as through a rectangular hole in the bottom center of the backboard surface. The rim also engages the bottom of the backboard, creating a second attachment point for the backboard to the post.
[0014] Preferably, fasteners, such as two spring-loaded index pins are attached to the upper surfaces of the two members with telescoping sections within. The bottom-most section is pulled out until its index hole matches up and is locked via the index pin. The upper telescoping section is advanced to the desired length (or all the way for regulation rim height) and the index pin is received into the nearest index hole. These holes are spaced about 3″ apart to provide this adjustment. After the telescoping sections are secured via the spring pins, the mast is raised to the operational angle which is preferably approximately 60 degrees from the horizontal, although other structurally sound angles of orientation may be employed. At this point, the collar to which the struts are pivoted is aligned with the lower folding member near its bottom end such that side holes align with through holes in the folding member; a spring pin is inserted through the collar and post member locking them together. Thus the post erection is completed.
[0015] The actual assembly sequence of the three subsystems starts with unlatching the cam locks securing the cover of the base storage box; the cover is then opened and the backboard, rim and post assembly are retrieved from the storage compartment. Then the cover is re-closed and securely latched by the cam locks. Now the folded post assembly is attached to the base by inserting the distal end into keyways and applying a clockwise twist action. The support struts are then inserted into their keyways on the base storage box cover. The articulated sections of the post assembly are then unfolded, and the telescoping sections are pulled out of their housing members. At this point, the angle of the post has been reduced to bring the distal end down to about 3.5 feet so the rim and backboard can be mounted. The rim and backboard are then attached via their respective fasteners, such as toggle latch clamps. The post is then raised to its play position and secured by inserting a spring pin through the collar assembly.
[0016] Disassembly of the three subsystems is started by lowering the post to the low intermediate position by removing the spring pin from the collar. Then the rim and backboard are detached. Once the post is lowered, the rim and backboard are detached by releasing their respective fasteners, such as one or more toggle latch clamps. Then the telescoping sections are pushed into their housing members and articulated sections are folded. The support struts are released from the base. Now the post assemble is released from the base by a counterclockwise twist and lift action. At this point, the backboard, rim and post assembly are placed in the base storage box and secured via cam locks. The two normal hinges and adjacent locking spring pins which are used with the articulated sections can be replaced with adjustable locking hinges of the type often used with adjustable high-end ladders. These are easily operated by pulling a handle or pushing a knob against spring resistance; they are more convenient and eliminate the separate spring pin parts.
[0017] In an alternate embodiment of this self-storing portable basketball goal, a different configuration with all components pre-attached to the inside of the lid of the watertight storage compartment is described. The post is in a ladder configuration with preferably two parallel structural members which are pre-attached to the backboard at their distal end. Single structural members can also be used. In operation, the lid of the storage compartment is opened vertically to 90 degrees and locked in place with one or more locking struts, preferably two locking struts. The two folding struts which are straightened into an oblique angle and locked. Attached to the lid are one or more, preferably two parallel post members which are preferable aluminum square tubing, although other tubing crossections may be employed. Each preferably has an equal length telescoping member within which is withdrawn to a desired height (after the other distal members are adjusted) and locked in place by a fastener, such as a spring pin which is inserted through a hole near the top end of the members attached to the lid and also through one of a line of holes in the telescoping members. The telescoping members are attached together by a horizontal shaft near their top distal ends. An articulated member is also hinged at this site on each side. These are swung over the top of the telescoping members and locked into a single prescribed position of about an angle of 48 degrees to the horizontal via spring pins adjacent to the hinges. The distal ends of these parallel angled members are themselves similarly preferably attached together by a horizontal shaft and pivoted to the backboard structural members via fasteners, such as hinges and spring pins. Although a unitary backboard can be used, for space saving storage, preferably the backboard has two folding wings, one at each side that must be opened and locked in the open position prior to play. The rim is hinged and is swung down and locked into position at a right angle to the backboard.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The present invention can best be understood in 15 connection with the accompanying drawings. It is noted that the invention is not limited to the precise embodiments shown in drawings, in which:
[0019] FIG. 1 is a perspective view of the self-storing portable basketball goal of this invention as erected and ready for use;
[0020] FIG. 2 is a side view of the post assembly as folded into a configuration which fits in the storage box;
[0021] FIG. 3 is a top view of the backboard assembly showing the toggle latch clamp locking configuration;
[0022] FIG. 4 is a back view of the backboard;
[0023] FIG. 5 is a top view of the rim assembly showing the toggle latch clamp attachment configuration;
[0024] FIG. 6 is a side view of the rim assembly;
[0025] FIG. 7 is a perspective view of the watertight foundation box with lid partially open;
[0026] FIG. 8 is a perspective view of the ballast box with removable bottom plate;
[0027] FIG. 9 is a side view of an excavation in progress with ballast box installed and excavator's feet extending below bottom of ballast box through the bottom hatch;
[0028] FIG. 10 is a side subterranean view of foundation box with storage compartment attached to the ballast box;
[0029] FIG. 11 is a side view of the basketball goal erected with an intermediate low position shown in dashed lines;
[0030] FIG. 12 is a top view of an auxiliary mounting plate showing the female keyways which are used to anchor the post assembly;
[0031] FIG. 13 is a perspective view of a kit consisting of three keyway plates which can be installed flush with a wooden gym floor to permit interior use of the basketball goal of this invention;
[0032] FIG. 14 is a perspective detail of an adjustable locking hinge which can be used with this invention;
[0033] FIG. 15 is a perspective view of an alternate embodiment of the self-storing basketball goal wherein all components are pre-attached to the lid of the watertight storage compartment, and
[0034] FIG. 16 is a side view of the alternate embodiment of FIG. 15 showing the details of the telescoping and articulated sections.
DETAILED DESCRIPTION OF THE INVENTION
[0035] FIG. 1 shows basketball goal 1 erected and ready for play. Area 3 is the playing area, while region 2 can be an adjacent lawn or sand or soil area. Post assembly 4 (as shown in FIGS. 1, 2 , and 11 ) includes of various components that are all attached together. It folds and telescopes into the compact configuration shown in FIG. 2 for storage in the watertight storage compartment of foundation box 10 .
[0036] As shown in FIG. 2 , post assembly 4 includes base pivot 15 , captive bottom telescoping section 16 , bottom main tube 17 , upper main tube 18 , captive upper telescoping tube 20 , backboard attachment tube 52 , and strut collar 25 with struts 26 and 27 and strut base pivots 28 and 29 .
[0037] Low friction sleeves are used within tubes 17 and 18 to facilitate easy travel of captive telescoping sections 16 and 20 respectively. The low friction sleeves are sized to come together to block over travel of the telescoping members 16 , 17 and 18 , 20 .
[0038] Lid 11 is hinged to box 10 by hinge 12 ; it has keyways under base pivot 15 and under strut pivots 28 and 29 . Folding horizontal strut 13 is pivoted on struts 26 and 27 keeping them spread apart and engaged with keyways in lid 11 when it is locked in the straight position.
[0039] Both backboard 33 and rim 32 are attached to the distal end section of post assembly 4 which is section 52 as shown in FIG. 2 . Note that tubing section 52 is hinged via hinge 53 to the distal end of telescoping tube 20 .
[0040] FIGS. 3 and 4 show backboard 33 with frame 35 , face board 36 (preferably polycarbonate), mounting crossbar 37 and lower rim accommodating region 38 . The frame 35 and mounting hardware (wall 39 , swinging gate with a fastener, such as a toggle latch clamp 41 and wall 40 with clamp hook 40 a ) are preferably aluminum components which can be welded in place. The enclosed area 42 engages post square tubing member 52 in a snug fit when toggle latch clamp 41 is drawn down. FIGS. 5 and 6 show the rim which has mounting features similar to those of backboard 33 . The clamp 41 is passed through notched slit 38 b of lower rim accommodating region 38 and engages the lower section of tube 52 . Walls 39 and 40 of the backboard rim mount advance through notched slits 38 b and 38 c capturing tongue bar 38 a , which is flush with the face of backboard frame 35 of backboard 33 . Slit 38 b is notched convexly outward to accommodate the width of clamp 41 pivotably attached to backboard claim wall 39 . Likewise, slit 38 c is also notched convexly outward to accommodate the width of hook 40 a of backward clamp wall 40 .
[0041] FIG. 7 shows foundation box 10 with watertight storage compartment 60 as sealed by lid 11 against elastomeric gasket 61 under the pressure provided by hinge 12 and cam locks 65 and 66 when in the closed position. Note the circular pattern of three keyways 64 . These engage three male key prongs 51 on the bottom of base pivot 15 when prongs 51 are inserted in the enlarged openings and then twisted in a clockwise direction. Front keyways 62 and 63 engage male key prongs 51 on the ends of strut pivots 28 and 29 when they are inserted and then spread apart. Note that as a safety feature, struts 26 and 27 cannot be inserted until the handles of cam locks 65 and 66 are turned out of the interference position; this turning action also engages the cam locks to secure lid 11 in a closed engagement with foundation box 10 . Note that the keyway openings in lid 11 are sealed internally with spaced apart covers to prevent water seepage while not blocking the keyways themselves. In some types of substrate, box 10 with the help of rim 14 will provide adequate pull-out resistance to act as a foundation for the basketball goal. However, in softer ground a ballast box 70 as in FIG. 8 is required. This is placed deeper down below foundation box 10 as shown in FIGS. 9 and 10 . Ballast box 70 has a hatch opening 73 on its bottom which provides access for the feet of a person during the excavation as shown in FIG. 9 . This makes it more convenient to carefully level box 70 ; 56 is the upper excavation which will accommodate foundation box 10 , while lower excavation 57 makes space for the person to be at a lower level. After the leveling is complete, area 57 is backfilled with material 55 and hatch cover 72 is bolted to the bottom using bolts through clearance holes 75 into threaded holes 76 . Ballast, such as rocks or broken concrete, can then be introduced into box 70 . Then foundation box 10 is attached to the rim of ballast box 70 above side walls 71 . Bolts through clearance holes 67 in flange 14 are screwed into threaded holes 74 to accomplish the attachment. Note that box 10 can be inverted and nested within box 70 for shipping purposes.
[0042] FIG. 11 shows a side view of goal 1 in the low position for attachment or detachment of backboard and rim (dashed lines), as well as in the deployed position. Note that collar 25 moves from the top of post section 17 to the bottom in making the transition. It is locked via a spring pin 82 when in the deployed position. Index pin 80 locks telescoping section 16 to section 17 at the extended position. Hinge 19 , between sections 17 and 18 , is locked by an adjacent spring pin. Index pin 81 adjusts the degree of extension of top telescoping member 20 via an array of holes on its top surface (about 3″ apart). Height h 1 is close to regulation height, while further extension of 20 will take it to its limit, and retraction inward will bring it down to height h 2 . Spring pin 83 locks in the appropriate angle between distal segment 52 and telescoping section 20 to insure the verticality of backboard 33 as segment 52 is rotated via hinge 53 . Telescoping member 16 can be retracted for a further lower height h 3 , such as six to eight feet above the ground.
[0043] FIG. 12 is a top view of an auxiliary mounting plate 85 with pattern of keyways 62 , 63 and 64 and straight keyways 62 and 63 at the same relative positions as on foundation box lid 11 . This rigid plate can be attached to a rigid in-ground framework or to a series of stakes via screw holes 86 at a location remote from the in-ground storage compartment. FIG. 13 shows a kit 88 including one three-keyway plate 89 and two identical straight keyway plates 90 . These can be easily installed so that their upper surface is flush with the floor level inside a gym. If the floor is wood, round depressions can be routed at the appropriate spacings and plates 89 and 90 are then simply screwed down with flat heat screws in the countersink clearance holes in the plates. This would permit use of the portable goal of this invention in an interior space.
[0044] While FIG. 12 shows keyways 62 flush with plate 85 , in a further embodiment, plate 85 can be recessed within the ground, acting as a ballast, whereby keyways 62 , 63 and 64 are elevated by structural tower posts (not shown) to be flush with the ground playing surface area.
[0045] FIG. 14 shows a heavy duty adjustable hinge 95 that can be substituted for hinges 19 and 53 (and their adjacent spring pins). This particular design is operated by pulling out handle 96 until it clicks open to release the hinge. By rotating the members to the desired position and clicking it back in under spring force, the hinge would be locked in the alternate position. The design illustrated is an invention of Boothe (U.S. Pat. No. 4,407,045). A similar push button operated adjustable locking hinge can also be used; an example is the invention of Lee (U.S. Pat. No. 6,711,780).
[0046] It is further noted that hinges 19 and 53 are on the rearward side of post assembly 4 , so that if a structural member or fastener fails, the backboard 33 will only fall rearward, away from the playing area.
[0047] An alternate embodiment of this invention is shown in FIGS. 15 and 16 . In this embodiment, all components are pre-attached; and fold and telescope such that they fit within a storage compartment in watertight foundation box 101 which may be attached to ballast box 130 via bolts through flange 102 . Lid 104 is the main attachment for the dual parallel posts that ultimately bear the weight of the other support elements as well as backboard 115 with folding rim 125 which is attached via hinge 126 . In the locked position, lid 104 is kept tightly closed via cam locks 105 , hinge 106 and gasket 103 . In the open position, two folding locking struts 107 , pivoted at one end at the inner sides of box 101 and at the distal end at lid 104 , are used to position lid 104 at a right angle to box 101 . Two square tubing sections 108 are attached to lid 104 . Telescoping sections 110 emanate from them with an array of holes which are used to set the desired rim height by using a spring pin through a single hole neat the top end of sections 108 (an index pin can also be used). Two parallel post members 112 are swung around on hinges 111 and locked at a preferable angle of 48 degrees (to the horizontal) using adjacent spring pins. Backboard 115 attached to support posts 122 is swung from the front side of members 112 into the deployed position via hinges 121 at each end of rod 120 and locked in the vertical position using adjacent spring pins and/or rigid strut 129 . To permit backboard 115 to fit into a smaller storage compartment, it has a central section 116 attached to support posts 122 . On each side of 116 are wing sections 117 which are hinged to 116 and are rotated parallel to 116 and locked in place with latches prior to use. FIG. 16 shows the motion of the various sections during the deployment or take-down operations (using dashed lines with arrow heads).
[0048] The alternate embodiment can be erected or taken down conveniently and quickly. The operation can be streamlined by replacing hinges 121 (and their adjacent spring pins) with two adjustable locking hinges such as are shown in FIG. 14 .
[0049] In the foregoing description, certain terms and visual depictions are used to illustrate the preferred embodiment. However, no unnecessary limitations are to be construed by the terms used or illustrations depicted, beyond what is shown in the prior art, since the terms and illustrations are exemplary only, and are not meant to limit the scope of the present invention.
[0050] It is further known that other modifications may be made to the present invention, without departing the scope of the invention, as noted in the appended Claims. | A modular self-storing basketball goal system includes a foundation box having a pivotable top cover movable from a horizontal closed position and a vertical open position for deployment of a basketball game upward therefrom. The basketball goal includes a post assembly having a backboard and rim attachable at a top end. The post, backboard and hoop are stored within the foundation box when the basketball game goal is not deployed. The post extends up from the top cover for deploying the basketball game goal. Folding locking struts support the top cover during use. The post assembly is telescoped and folded down to fit into the foundation box, along with the backboard and hoop for storage. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present Application claims priority from U.S. Provisional Patent Application No. 61/018,657 filed Jan. 2, 2008, entitled “Optical Substrate For Reduced Background Flourescence,” which is incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Aspects of the present invention relate generally to the field of microscopy and, more specifically, to methods and apparatuses for reducing background fluorescence in fluorescence microscopy.
2. Description of Related Art
The most common form of fluorescence microscope is an epifluorescence microscope. In this context, “epifluorescence” generally implies that the incidence illumination comes from the same direction or side of the illuminated sample from which fluorescence is detected. Of particular interest is the epifluorescence microscope configuration in which the excitation and the collection or emission beams both pass through the backside of the microscope coverslip, slide, or other optical substrate, upon which the sample being viewed or imaged is located.
A common problem when working with optical substrates, such as glass microscope slides or plastic microtiter plate, is that the backside of the optical substrate becomes contaminated with fluorescent material. Fluorescent contaminants located on the backside of an optical substrate are out of focus relative to the fluorescence of interest and tend to cover or interfere with the fluorescence of interest over a large area. Cleaning fluorescent contaminants from the backside of the optical substrate is very difficult, requiring extra labor and handling of the substrate; increased potential of fouling the sample of interest; slower processing times; and increased costs. In some cases, the fluorescent contaminants are embedded in the surface of the optical substrate and may be impossible to remove using practical, safe solvents and cleaning agents.
In addition to the problem of illuminating out-of-focus contaminants, a second problem lies with background fluorescence arising from the auto-fluorescence of the optical substrate material itself. Even transparent materials such as glass or plastic can produce a detectable amount of fluorescence when the material is thick enough. The fundamental problem is that fluorescence intensity is proportional to the amount of material. Because a typical microscope slide is 1 mm thick, the total thickness of the slide is about two to three orders of magnitude thicker than the target of interest (about 1-10 um thick). From a very simple perspective, the fluorescent probe used to label the target must be at least 300× more fluorescent than the glass in order to achieve a 3:1 signal-to-background ratio. In other words, a large amount of background fluorescence from the substrate will degrade the performance of the instrument by reducing the signal-to-background ratio, which is a critical performance characteristic.
Various microscopy systems and techniques have been employed to reduce or avoid the problems associated with background fluorescence on optical substrates including: laser scanning systems; wide-field imaging systems; evanescent illumination systems; and wide-field systems with oblique illumination. Laser scanning systems have been able to minimize backside problems by illuminating only a single point at a time. The disadvantages of laser scanning systems when attempting to build highly reliable and highly repeatable diagnostic applications are well known. Laser scanning systems are not practical for all types of instruments and have limited ability to perform diagnostic assays.
Wide-field imaging systems that use epifluorescent illumination are the most vulnerable to backside contamination, because the path of the illumination beam exactly matches the path of the image collection optics. The illumination beam passes directly through the backside of the substrate, in the opposite direction of the image collection rays. Similarly, the illumination beam strikes the entire thickness of the substrate on its way to the target.
Evanescent wave illumination is another alternative illumination method. The illumination is directed to the surface of the glass from outside the field-of-view. When illuminated at the so-called “critical angle”, the illumination beam will travel through an evanescent wave along the surface of the glass. The strength of this technique is that only objects along the surface of the glass are illuminated. The weaknesses of this technique include: dim, inefficient illumination; many fluorescent probes are not illuminated because the illuminated region is thin; difficult to align and maintain, especially in a commercial instrument; propagation of the illumination is dependent on surface cleanliness; and illumination shadowing will affect fluorescent signal strength. Evanescent illumination has only been practiced in situations involving laboratory research and is not a promising technique for general purpose fluorescence assays.
Wide-field systems with oblique illumination have some ability to avoid illumination of the backside contamination. The illumination beam comes from outside the cone angle of the objective lens. Many of the illumination rays reach the target without passing through the region of the substrate that is viewed by the objective. When using a simple, planar substrate like a microscope slide, however, it is nearly impossible to avoid significant illumination of the substrate. Backside illumination and bulk material illumination can still limit instrument performance. For example, the wide-field, oblique illumination scanner ArraryWoRx, designed and manufactured by Applied Precision, the assignee of the present invention, unavoidably illuminates one or more optical substrate surfaces that are not in the object plane of the scanner. The backside of the target is partially illuminated, causing undesired background fluorescence. To avoid such background fluorescence it is necessary to clean the backside of the scan target or optical substrate. Because the backside surface is part of the object to be scanned, the cleanliness is difficult to control. The quality of the scanned image is overly dependent on the fabricator of the optical substrate and also the instrument operator.
What is needed in the field is a means to eliminate or avoid illumination of out-of-focus surfaces and fluorescent contaminants located on optical substrates.
BRIEF SUMMARY OF THE INVENTION
Certain embodiments of the present invention comprise a unique optical substrate design allows a target to be illuminated with minimal illumination of undesired surfaces within the image collection ray path. A non-rectangular substrate provides different surfaces through which a target is illuminated and imaged, thereby preventing illumination rays from crossing the substrate surface through which the target is imaged.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exemplary schematic representation of a cross-section of a three millimeter thick embodiment of the present optical substrate invention.
FIG. 2 is an exemplary schematic representation of a cross-section of a five millimeter thick embodiment of the present optical substrate invention.
FIG. 3 is an exemplary schematic representation of the top side of a single panel embodiment of the present optical substrate invention.
FIG. 4 is an exemplary schematic representation of the top side of a stripe-style panel embodiment of the present optical substrate invention.
FIG. 5 is an exemplary schematic representation of a cross-section of an optical substrate attachment embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will now be described in detail with reference to the drawings, which are provided as illustrative examples so as to enable those skilled in the art to practice the invention. Notably, the figures and examples below are not meant to limit the scope of the present invention to a single embodiment, but other embodiments are possible by way of interchange of some or all of the described or illustrated elements. Wherever convenient, the same reference numbers will be used throughout the drawings to refer to same or like parts. Where certain elements of these embodiments can be partially or fully implemented using known components, only those portions of such known components that are necessary for an understanding of the present invention will be described, and detailed descriptions of other portions of such known components will be omitted so as not to obscure the invention. In the present specification, an embodiment showing a singular component should not be considered limiting; rather, the invention is intended to encompass other embodiments including a plurality of the same component, and vice-versa, unless explicitly stated otherwise herein. Moreover, applicants do not intend for any term in the specification or claims to be ascribed an uncommon or special meaning unless explicitly set forth as such. Further, the present invention encompasses present and future known equivalents to the components referred to herein by way of illustration.
Certain embodiments of the present invention provide systems and methods for addressing and resolving the problems associated with background fluorescence of substrates in epifluorescence microscope systems. Certain aspects of the invention provide means for illuminating a fluorescently labeled target while avoiding unnecessary illumination of optical surfaces that are out of the image plane.
Certain embodiments provide a unique substrate shape that allows an illumination beam to reach the target without passing through unnecessary surfaces within the optical system. The thickness and surface angles of the substrate are carefully chosen to provide separate ray paths for both the illumination and collection or emission beams. A non-rectangular substrate allows the illumination to enter the substrate at an angle yielding a number of important advantages, such as: minimal amount of reflection and refraction off the air-substrate interface; reduced backside illumination; maximum illumination efficiency; manageable refraction of the illumination beam; and minimal substrate autofluorescence within the image collection ray path.
As shown in FIGS. 1 and 2 , in certain embodiments, the present invention may utilize a non-rectangular substrate 10 . The substrate may have a flat sample surface 20 . An image collection surface 30 oriented approximately parallel to sample surface 20 and an illumination surface 40 at an angle not parallel to either sample surface 20 or image collection surface 30 .
In practice, an illumination beam 50 enters the substrate at illumination surface 40 . Illumination beam 50 may be incident upon illumination surface 40 at an angle approximately perpendicular to illumination surface 40 or at a non-perpendicular angle as provided by illumination optics 60 of the microscope system being used. The sample of interest or target 70 may be located upon sample surface 20 and positioned in order to receive illumination beam 50 . Imaging optics (not shown) may be positioned and configured with respect to the bottom of target 70 and the image collection surface 30 such that the optics may receive fluorescence or excitation rays 80 emitted from target 70 .
FIG. 1 shows one example of an embodiment of the invention in which optical substrate 10 is designed to have a depth or thickness of approximately three (3) millimeters and a sample surface 20 width of approximately 7.1 millimeters. Illumination optics 60 may have a 0.20 numerical aperture lens emitting illumination beam 50 . Illumination optics 60 may be oriented substantially perpendicular to illumination surface 40 . Target 70 is 3.4 millimeters wide and represented by the dark horizontal line across top of sample surface 20 . The overall shape of optical substrate 10 may be described as non-rectangular due the angle and orientation of illumination surface 40 which appear as cut corners. FIG. 2 shows an example of an embodiment in which the thickness of optical substrate 10 is five (5) millimeters. The additional thickness of optical substrate 10 may provide greater xy tolerance of the substrate and target 70 .
As shown in FIG. 1 , the cut corner configuration may be implemented on one or more sides of optical substrate 10 . A multisided, cut corner configuration may enable imaging or scanning of target 70 from various perspectives and may facilitate imaging of an entire target in a manner that would not otherwise be possible from a single side.
In addition to the example configurations depicted in FIGS. 1 and 2 , a variety of other combinations of substrate thickness, corner angle, substrate geometry, illumination geometry and imaging geometry are possible. Careful selection of the substrate geometry, illumination cone angle, and image collection angle may provide for customization and optimization of the present invention to a variety of fluorescence microscopy systems.
Certain embodiments may be implemented with a shape that is compatible with either a “single panel” or “stripe” style imaging method. In the single panel style, shown in FIG. 3 , the aspect ratio of the width and height of the target corresponds to the aspect ratio of the region-of-interest used on the electronic image sensor. By design, the field-of-view of a single image acquired by the image sensor is typically large enough to gather information about the entire target. The single panel style substrate may also have approximately the same width and height as the target area, when viewed from the above.
The stripe imaging configuration, shown in FIG. 4 , takes advantage of a special camera readout method referred to herein as “time delay integration” or “TDI.” A TDI method is described in U.S. patent application Ser. No. 11/2202,745 which is commonly owned with the present application and which is herein incorporated by reference in its entirety. In the stripe imaging configuration, the height or width of the substrate and target region is elongated. The benefit of such a configuration is that the size of the target region can be extended indefinitely. The cross-section of the single panel style substrate is essentially extruded along the stripe imaging direction.
In certain embodiments, optimization of the illumination ray path through the substrate is achieved with a conventional substrate, such as a microscope slide, by utilizing an appropriately configured optical substrate attachment. As shown in FIG. 5 , illumination beam 50 is incident upon an optical substrate attachment 90 at illumination surface 40 . Optical substrate attachment 90 further comprises optical substrate attachment surface 110 which may be positioned proximate to conventional substrate 100 . Illumination beam 50 may pass through optical substrate attachment 90 and enter conventional substrate 100 in the same manner and imparting the same advantages as described for the embodiments described in FIGS. 1 and 2 . In other words, in this configuration, it remains possible to illuminate a target without illumination beam 50 crossing an image collection surface.
The material used to fabricate optical substrate attachment may be selected to have a similar index of refraction as that of the conventional substrate, so as to minimize refraction between the attachment and the substrate. To improve transmission and reduce undesired scattering, an index matching fluid or adhesive material may be used between the attachment and the substrate. In practice, optical substrate attachment 90 may take various forms including: a hollow ring, a strip, a solid trapezoid or other appropriate geometry. In this embodiment the image collection surface may be the backside of the conventional substrate or a surface of the optical substrate attachment.
It will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the claimed invention.
Additional Descriptions of Certain Aspects of the Invention
The foregoing descriptions of the invention are intended to be illustrative and not limiting. For example, those skilled in the art will appreciate that the invention can be practiced with various combinations of the functionalities and capabilities described above, and can include fewer or additional components than described above. Certain additional aspects and features of the invention are further set forth below, and can be obtained using the functionalities and components described in more detail above, as will be appreciated by those skilled in the art after being taught by the present disclosure.
Certain embodiments of the invention provide an optical substrate comprising a sample surface, an image collection surface substantially parallel to the sample surface, and an illumination surface positioned non-parallel to the image collection surface. In some of these embodiments, the optical substrate comprises one or more illumination surfaces. In some of these embodiments, the optical substrate comprises glass. In some of these embodiments, the optical substrate comprises plastic.
Certain embodiments of the invention provide a method of imaging a sample, the method comprising positioning a sample on a sample surface of an optical substrate, illuminating the sample with an illumination beam incident upon an illumination surface wherein the illumination surface is positioned non-parallel to the sample surface and imaging the sample through an image collection surface oriented substantially parallel to the sample surface. In some of these embodiments, the illumination comprises illuminating the sample through one or more the illumination surfaces. In some of these embodiments, the imaging employs time delay integration. Certain embodiments of the invention provide an optical substrate attachment comprising an optical substrate attachment surface and an illumination surface positioned non-parallel to the optical substrate attachment surface. In some of these embodiments, the optical substrate attachment comprises one or more of the illumination surfaces. In some of these embodiments, the optical substrate attachment comprises glass. In some of these embodiments, the optical substrate attachment comprises plastic.
Certain embodiments of the invention provide a method of imaging a sample comprising positioning an optical substrate proximate to an optical substrate attachment surface, providing an illumination beam to an optical substrate attachment illumination surface wherein the illumination surface is non-parallel to the substrate attachment surface and imaging the sample through an image collection surface oriented substantially parallel to the substrate attachment surface. In some of these embodiments, the illumination beam is provided to one or more the illumination surfaces. In some of these embodiments, the imaging employs time delay integration.
Certain embodiments of the invention provide an optical substrate. In some of these embodiments, the optical surface comprises a sample surface, an image collection surface substantially parallel to the sample surface and an illumination surface positioned non-parallel to the image collection surface. In some of these embodiments, the optical substrate is a non-rectangular optical substrate. In some of these embodiments, the optical substrate comprises a plurality of illumination surfaces positioned non-parallel to the image collection surface. In some of these embodiments, each of the plurality of illumination surfaces is non-parallel to the sample surface. In some of these embodiments, the sample surface is substantially flat. In some of these embodiments, the optical substrate comprises glass and/or plastic. Some of these embodiments further comprise an optical substrate attachment. In some of these embodiments, the form of the optical substrate attachment comprises one or more of a hollow ring element, a strip element or a solid trapezoidal element. In some of these embodiments, the thickness of the optical substrate is about three millimeters. In some of these embodiments, the thickness of the sample surface is about 7.1 millimeters. In some of these embodiments, the thickness of the optical substrate is about five millimeters.
Certain embodiments of the invention provide methods for imaging a sample. Some of these embodiments comprise positioning a sample on a sample surface of an optical substrate, illuminating the sample with an illumination beam incident upon an illumination surface, wherein the illumination surface is positioned non-parallel to the sample surface and imaging the sample through an image collection surface oriented substantially parallel to the sample surface. In some of these embodiments, the optical substrate comprises an optical substrate attachment surface and the illumination surface includes an optical substrate attachment illumination surface. In some of these embodiments, the illumination comprises illuminating the sample through one or more of the illumination surfaces. In some of these embodiments, the imaging step includes using time delay integration.
Certain embodiments of the invention provide optical substrate attachments. Some of these embodiments comprise an optical substrate attachment surface aligned with a first plane and an illumination surface aligned with a second plane that is unaligned with the first plane. Some of these embodiments further comprise one or more additional illumination surfaces, each of the additional illumination surfaces is aligned with a plane unaligned with the first plane. In some of these embodiments, the optical substrate attachment comprises glass and/or plastic.
Certain embodiments of the invention provide a non-rectangular optical substrate. Some of these embodiments comprise a flat sample surface, an image collection surface oriented approximately parallel to the sample surface, and one or more illumination surfaces at an angle not parallel to either the sample surface or the image collection surface. In some of these embodiments, the thickness of the optical substrate is approximately three millimeters. In some of these embodiments, the thickness of the sample surface is approximately 7.1 millimeters. In some of these embodiments, the thickness of the optical substrate is approximately five millimeters. Some of these embodiments further comprise an optical substrate attachment. In some of these embodiments, the optical substrate attachment is in the form of a hollow ring, a strip, or a solid trapezoid. In some of these embodiments, the optical substrate comprises glass. In some of these embodiments, the optical substrate comprises plastic.
Certain embodiments of the invention provide methods for imaging a sample. Some of these embodiments comprise positioning a sample on a sample surface of an optical substrate, illuminating the sample with an illumination beam incident upon an illumination surface, wherein the illumination surface is positioned non-parallel to the sample surface, and imaging the sample through an image collection surface oriented substantially parallel to the sample surface. In some of these embodiments, the illuminating comprises illuminating the sample through one or more illumination surfaces. In some of these embodiments, the imaging comprises time delay integration. In some of these embodiments, the optical substrate further comprises an optical substrate attachment comprising an optical substrate attachment surface and an illumination surface positioned non-parallel to the optical substrate attachment surface. In some of these embodiments, the optical substrate attachment comprises one or more illumination surfaces. In some of these embodiments, the optical substrate attachment comprises glass and/or plastic.
Although the present invention has been described with reference to specific exemplary embodiments, it will be evident to one of ordinary skill in the art that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. | A new optical substrate design allows a target to be illuminated with minimal illumination of undesired surfaces within the image collection ray path. The non rectangular substrate provide different surfaces through which a target is illuminated and imaged and thereby prevents illumination rays from crossing the substrate surface through which the target is imaged | 6 |
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates generally to two piece fasteners and more particularly to improved flush head shear type two piece fasteners.
Two piece flush head shear type fasteners typically include a pin having a frusto conically shaped head at one end of an elongated shank which is designed to fit within a suitably prepared countersunk opening in workpieces to be joined. The shank portion of such fasteners generally includes a plurality of lock grooves projecting outwardly beyond the workpieces, a separable pintail portion on the outer end thereof normally having a plurality of pull grooves provided thereon and a collar adapted to be swaged into engagement with the lock grooves.
Such fasteners are well known in the art and are designed to be installed or set by an installation tool which includes a jaw assembly engageable with the pull grooves of the pintail portion and a swaging anvil engageable with the collar. As the tool is actuated the jaws exert a pulling action on the pin and the swaging anvil applies the reaction force to the collar. During the initial or primary clinching operation, the workpieces are first drawn together and the pin drawn into and fully seated within the prepared opening. As the relative free movement between the pin and collar is taken up continued pulling action of the tool will increase the tensile loading on the pin and thereby produce an increasing reactionary force on the collar. As these forces increase, the swaging anvil will operate to swage the collar into the outer lock grooves on the pin thereby providing a primary clinch or lock therebetween and preventing any further relative free movement between the pin and collar. Thereafter, the continued swaging of the collar causes an axial elongation thereof forcing the other end of the collar to exert a clamping force on the workpices and resulting in increased tensile loading on the pin. This increased pin loading due to collar elongation is commonly referred to as secondary clinch loading. Thus, during installation or setting of the fastener, the preformed head provided on the pin is subjected to the combined loading from the action of the installation tool and the secondary clinch loading.
A number of factors influence the actual magnitude of these combined loading forces several of which also directly affect the strength of the installed fastener such as for example collar hardness. In applications requiring relatively high strength it is desirable to use as hard a collar as possible in order to increase the clamping force on the workpieces as well as to increase the fatigue life and improve tensile strength characteristics. However, as collar hardness increases, the required installation loads also increase thus resulting in increased loading on the fastener and the preformed head. Thus, as collar hardness increases these combined forces may exceed the rated head strength of the pin resulting in a partial yielding of the head and degradation of the resulting joint strength. Typically, such degradation is physically evidenced by a dishing or dimpling of the otherwise relatively flat surface of the pin head. Such occurrences are most commonly experienced in conjunction with setting of the shear type fasteners which have a substantially smaller head relative to pin diameter. Therefore, it appears that the head size presents a limiting factor as to the maximum collar hardness which may be used in conjunction therewith and therefore limits the tensile strength and clamping forces which may be obtained. It is not practical nor commercially desirable to design different size preformed heads for fasteners of the same nominal shank diameter for varying collar hardness as each head size would then require separate hole preparation tools to be used in order to assure proper sizing of the countersunk opening.
The present invention, however, provides an improved fastener having a raised head portion of a dimension proportioned to the anticipated peak installation load resulting from both installation tool loading and secondary clinch loading and proportioned to the relative shear strength and diameter of the pin so as to substantially reduce or eliminate the dishing of the fastener head during setting thereof and provide a fastener having a substantially flat flush head when set. Further, the raised head portion results in a pin having a head of increased shear strength thus enabling use of collars of increased hardness resulting in a higher tensile strength fastening system while allowing existing standard hole preparation tools to be utilized. Also, because the frequency of rejected head installations is substantially reduced, cost savings will be realized from the reduction in expenditure of materials and labor attendent with the removal and reinstallation of rejected fasteners.
Further, the head design of the present invention may provide a positive indication or properly installed fasteners. More specifically, because the dimensions of the raised surface portion of the head may be controlled so as to require a predetermined loading in order to flatten out this raised surface portion, the degree of flatness will be proportionate to this loading and also to the degree of clamping force the workpieces are subjected to due to secondary clinch loading. Thus, insufficient "flatness" may provide an indication of inadequate clamping or preloading of the workpieces which may result in premature fatigue failure whereas excessive "flatness" or even dishing may indicate excessive loading and possible damage to the workpieces within the area surrounding the joint as well as reduced tensile strength due to head degradation.
Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectioned elevational view of a two piece flush head pull type fastener in accordance with the present invention shown prior to setting thereof;
FIG. 2 is a plan view of the outer surface of the performed head provided on the fastener of FIG. 1; and
FIG. 3 is a view similar to that of FIG. 1 but showing the fastener thereof in a finally set condition.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and in particular to FIG. 1, there is shown a fastener in accordance with the present invention indicated generally at 10 and comprising a pin 12 inserted within prepared aligned openings 14 and 16 provided in workpieces 18 and 20 and a collar member 22 assembled thereto in preparation for setting.
Pin 12 includes a shank portion 24 of a nominal diameter "d" and having a head 26 at one end, a separable pintail portion 28 at the other end thereof, a plurality of annular locking grooves 30 between head 26 and pintail portion 28 and a breakneck groove 32 disposed between the locking grooves 30 and pintail portion 28.
Preformed head 26 includes a generally conically shaped sidewall 34 designed to mate with a similarly shaped countersunk portion 36 of opening 14 and forming an included angle α typically on the order of approximately 100°. The outer edge of countersunk portion 36 has a diameter "A" which is commonly referred to as the theoretical head intersection diameter. The outwardly facing surface of head 26 is defined by a relatively flat raised central surface portion 38 positioned a distance "H" above a plane defined by the outer surface 41 of workpiece 18 and having a diameter "D". An annular beveled or slightly inclined surface portion 40 surrounds raised surface portion 38 and extends between the periphery of portion 38 and the peripheral edge 42 of head 26.
As shown, head 26 has a total axial height "T" which is measured between approximately the point of intersection of sidewall 34 with shank portion 20 and raised surface portion 40 and is equal to the sum of the dimension "L" measured between the point of intersection of sidewall 34 and shank portion 20 and surface 40 of workpiece 18 and the dimension "H".
As previously mentioned, pull type fasteners are subject to tensile loading during installation which may exceed the designed head shear strength due to the combined forces of the pulling tool and secondary clinch loading particularly in such fasteners designed for shear loading as opposed to those designed for tensile loading. In such fasteners having a conventionally shaped outer head surface this tensile loading may result in excessive head deformation. In order to minimize this deformation, it has been necessary to use softer collars than may otherwise be desired so as to reduce secondary clinch loading. However, the use of softer collars reduces the tensile strength of the installed fastener.
However, the present invention enables the use of collars of increased hardness by providing a head having an increased total height which operates to reduce the head shear stress experienced due to the increased tensile loading during setting. Further, the dimension "H" of the raised surface portion 38 is directly proportioned relative to the difference between the installation loading and the desired maximum head strength such that as secondary clinch loading increases during setting of the fastener up to the desired maximum, the head will yield thereby relieving further secondary clinch loading and allowing raised surface portion 38 to be drawn toward surface 40 so as to form a substantially flat head on the installed fastener.
For any diameter pin this dimension "H" may be calculated by the following formula: ##EQU1## P P =anticipated peak installation loading P D =maximum desired head strength
A=theoretical head intersection diameter
In order to achieve full advantage of the increased head axial length as well as to facilitate of a substantially flat outer surface on the set fastener, it is preferable that the diameter "D" of the raised surface portion be approximately equal to the nominal diameter "d" of the pin.
The incremental increase in head axial length operates to increase the overall shear strength of the head and further increase the load to which the pin may be subjected before the material yields.
Once installation loading due to the combined effect of the pulling action of the tool and secondary clinch loading increases to a sufficient magnitude, the pin head will begin to yield or plastically deform thereby drawing raised surface portion toward the plane defined by surface 41 of workpiece 18. As head 26 yields, however, the effect is to relieve to some degree the secondary clinch loading which in turn will reduce the total installation loading on the pin head to a point at which the installation load will be below the load necessary to cause yielding.
In a conventional flush head shear type fastener, as the yield strength of the head is exceeded during a peak installation loading, the shear area over which the load is distributed is decreased due to the dishing of the head. Further, as the total shear area provided is less than in the present invention, the yielding will occur at a lower loading and further will require a greater amount of deformation in order to reduce to a lower magnitude, the result being significant dishing and therefore significant reduction in head shear strength during peak installation loading.
However, as shown in FIG. 2, with the increased shear area provided by the raised surface portion, the magnitude of loading at which yield occurs is increased sufficiently such that the amount of head deformation necessary to relieve the loading to a point where the stress on the head is below the yield strength is substantially reduced. The dimension of the raised surface area is thus proportioned such that under installation loading the head yield strength may be exceeded resulting in plastic deformation thereof, the raised surface portion will be drawn axially toward the workpieces eliminating what otherwise would be a dishing effect and thereby producing a relatively flat flush head surface disposed in substantially coplanar relationship with the workpiece surface. The axial length of the head is thus preserved thereby affording a shear strength commensurate with and capable of affording a fastened joint having a tensile strength at least equal to the minimum desired tensile strength. The required axial length of the fastener as thus set may then be approximately determined by the following formula
L=(P.sub.D /df.sub.su)
wherein f su equals the pin material rated shear strength.
It should also be noted that not only does the head design of the present fastener enable use of collars of increased hardness for a given size head thereby providing a fastened joint having increased tensile strength, improved and controlled workpiece clamping but the reduction in height of the raised surface portion provides physical evidence that the desired clamping force on the workpieces has been obtained.
While it will be apparent that the preferred embodiment of the invention disclosed is well calculated to provide the advantages and features above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims. | A two piece flush type fastener is provided with an improved head structure which includes a raised dish compensating portion on the outer end thereof the height of which is proportioned relative to anticipated peak installation loads, nominal pin diameter and material shear strength such that upon setting of the fastener the head will controllably yield so as to provide a substantially flat head surface on the installed fastener and eliminate the reduction in head strength which may accompany excessive dishing of the head outer surface. The dish compensating raised surface portion on the head also enables formation of a higher tensile strength joint having improved fatigue performance for a given size head. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a non-provisional application which claims priority to U.S. Provisional Applications 61/001,418, filed Nov. 1, 2007. The aforementioned application is incorporated in full by reference herein.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The invention relates generally to cancer monitoring and assessing disease progression in metastatic cancer patients, based on the presence of morphologically intact circulating cancer cells (CTC) in blood. More specifically, methods, reagents and apparatus are described for assessing circulating cancer cells in animal models.
[0004] 2. Background Art
[0005] Non-hematogenous epithelial tumor cells were first identified in the blood of a breast cancer patient over 150 years ago. Since then, CTC's have been shown to be a critical link between primary cancer, a disease stage at which cure is possible, and metastatic disease, which continues to be the leading cause of death for most malignancies. Clinical studies have shown that CTC's are a powerful prognostic and predictive biomarker in metastatic breast cancer, and similar findings have been reported in prostate cancer and colorectal cancer. From this data, CTC's have been shown to be representative of the underlying biology driving metastatic cancer and suggest that further cellular and molecular analyses of these cells can reveal new insights into molecular regulation of metastasis and response to therapy.
[0006] Research on the role of CTC in metastasis and expansion of their use as a biomarker in pharmacokinetic and pharmacodynamic studies has been limited to the clinical phase of drug development. It is generally accepted that most cancer patients are not killed by their primary tumor, but they succumb instead to metastases: multiple widespread tumor colonies established by malignant cells that detach themselves from the original tumor and travel through the body, often to distant sites. The most successful therapeutic strategy in cancer is early detection and surgical removal of the tumor while still organ confined. Early detection of cancer has proven feasible for some cancers, particularly where appropriate diagnostic tests exist such as PAP smears in cervical cancer, mammography in breast cancer, and serum prostate specific antigen (PSA) in prostate cancer. However, many cancers detected at early stages have established micrometastases prior to surgical resection. Thus, early and accurate determination of the cancer's malignant potential is important for selection of proper therapy.
[0007] If a primary tumor is detected early enough, it can often be eliminated by surgery, radiation, or chemotherapy or some combination of those treatments. Unfortunately, the metastatic colonies are difficult to detect and eliminate and it is often impossible to treat all of them successfully. Therefore, metastasis can be considered the conclusive event in the natural progression of cancer. Moreover, the ability to metastasize is a property that uniquely characterizes a malignant tumor.
[0008] Based on the complexity of cancer and cancer metastasis and the frustration in treating cancer patients over the years, many attempts have been made to develop diagnostic tests to guide treatment and monitor the effects of such treatment on metastasis or relapse.
[0009] One of the first attempts to develop a useful test for diagnostic oncology was the formulation of an immunoassay for carcinoembryonic antigen (CEA). This antigen appears on fetal cells and reappears on tumor cells in certain cancers. Extensive efforts have been made to evaluate the usefulness of testing for CEA as well as many other “tumor” antigens, such as prostate specific antigen (PSA), CA 15.3, CA 125, prostate-specific membrane antigen (PSMA), CA 27.29, p27 found in either tissue samples or blood as soluble cellular debris.
[0010] Additional tests used to predict tumor progression in cancer patients have focused upon correlating enzymatic indices like telomerase activity in biopsy-harvested tumor samples with an indication of an unfavorable or favorable prognosis (U.S. Pat. No. 5,693,474; U.S. Pat. No. 5,639,613). Assessing enzyme activity in this type of analysis can involve time-consuming laboratory procedures such as gel electrophoresis and Western blot analysis. Also, there are variations in the signal to noise and sensitivity in sample analysis based on the origin of the tumor. Despite these shortcomings, specific soluble tumor markers in blood can provide a rapid and efficient approach for developing a therapeutic strategy early in treatment. For example, detection of serum HER-2/neu and serum CA 15-3 in patients with metastatic breast cancer have been shown to be prognostic factors for metastatic breast cancer (Ali S. M., Leitzel K., Chinchilli V. M., Engle L., Demers L., Harvey H. A., Carney W., Allard J. W. and Lipton A., Relationship of Serum HER-2/neu and Serum CA 15-3 in Patients with Metastatic Breast Cancer, Clinical Chemistry, 48(8):1314-1320 (2002)). Increased HER-2/neu results in decreased response to hormone therapy, and is a significant prognostic factor in predicting responses to hormone receptor-positive metastatic breast cancer. Thus in malignancies where the HER-2/neu oncogene product is associated, methods have been described to monitor therapy or assess risks based on elevated levels (U.S. Pat. No. 5,876,712). However in both cases, the base levels during remission, or even in healthy normals, are relatively high and may overlap with concentrations found in patients, thus requiring multiple testing and monitoring to establish patient-dependent baseline and cut-off levels.
[0011] In prostate cancer, PSA levels in serum have proven to be useful in early detection. When used with a follow-up physical examination and biopsy, the PSA test has improved detection of prostate cancer at an early stage when it is best treated.
[0012] However, PSA or the related PSMA testing leaves much to be desired. For example, elevated levels of PSA weakly correlate with disease stage and appear not to be a reliable indicator of the metastatic potential of the tumor. This may be due in part to the fact that PSA is a component of normal prostate tissue and benign prostatic hyperplasia (BHP) tissue. Moreover, approximately 30% of patients with alleged localized prostate cancer and corresponding low serum PSA concentrations, may have metastatic disease (Moreno et al., Cancer Research, 52:6110 (1992)).
Genetic Markers:
[0013] One approach for determining the presence of malignant prostate tumor cells has been to test for the expression of messenger RNA from PSA in blood. This is being done through the laborious procedure of isolating all of the mRNA from the blood sample and performing reverse transcriptase PCR. No significant correlation has been described between the presence of shed tumor cells in blood and the ability to identify which patients would benefit from more vigorous treatment (Gomella L G., J of Urology, 158:326-337 (1997)). Additionally, false positives are often observed using this technique. There is an added drawback, which is that there is a finite and practical limit to the sensitivity of this technique based on the sample size. Typically, the test is performed on 10 5 to 10 6 cells separated from interfering red blood cells, corresponding to a practical lower limit of sensitivity of one tumor cell/0.1 ml of blood (about 10 tumor cells in one ml of blood) before a signal is detected. Higher sensitivity has been suggested by detecting hK2 RNA in tumor cells isolated from blood (U.S. Pat. No. 6,479,263; U.S. Pat. No. 6,235,486).
[0014] Qualitative RT-PCR based studies with blood-based nucleotide markers has been used to indicate that the potential for disease-free survival for patients with positive CEA mRNA in pre-operative blood is worse than that of patients negative for CEA mRNA (Hardingham J. E., Hewett P. J., Sage R. E., Finch J. L., Nuttal J. D., Kotasel D. and Dovrovic A., Molecular detection of blood-borne epithelial cells in colorectal cancer patients and in patients with benign bowel disease, Int. J. Cancer 89:8-13 (2000): Taniguchi T., Makino M., Suzuki K., Kaibara N., Prognostic significance of reverse transcriptase-polymerase chain reaction measurement of carcinoembryonic antigen mRNA levels in tumor drainage blood and peripheral blood of patients with colorectal carcinoma, Cancer 89:970-976 (2000)). The prognostic value of this endpoint is dependent upon CEA mRNA levels, which are also induced in healthy individuals by G-CSF, cytokines, steroids, or environmental factors. Hence, the CEA mRNA marker lacks specificity and is clearly not unique to circulating colorectal cancer cells.
[0015] The aforementioned studies, while seemingly prognostic under the experimental conditions, do not provide for consistent data with a long follow-up period or at a satisfactory specificity. Accordingly, these efforts have proven to be somewhat futile as the appearance of mRNA for antigens in blood have not been generally predictive for most cancers and are often detected when there is little hope for the patient.
[0016] In spite of this, real-time reverse transcriptase-polymerase chain reaction (RT-PCR) has been the only procedure reported to correlate the quantitative detection of circulating tumor cells with patient prognosis. Real-time RT-PCR has been used for quantifying CEA mRNA in peripheral blood of colorectal cancer patients (Ito S., Nakanishi H., Hirai T., Kato T., Kodera Y., Feng Z., Kasai Y., Ito K., Akiyama S., Nakao A., and Tatematsu M., Quantitative detection of CEA expressing free tumor cells in the peripheral blood of colorectal cancer patients during surgery with real-time RT-PCR on a Light Cycler, Cancer Letters, 183:195-203 (2002)). These results suggest that tumor cells were shed into the bloodstream (possibly during surgical procedures or from micro metastases already existing at the time of the operation), and resulted in poor patient outcomes in patients with colorectal cancer. The sensitivity of this assay provided a reproducibly detectable range similar in sensitivity to conventional RT-PCR. As mentioned, these detection ranges are based on unreliable conversions of amplified product to the number of tumor cells. The extrapolated cell count may include damaged CTC incapable of metastatic proliferation. Further, PCR-based assays are limited by possible sample contamination, along with an inability to quantify tumor cells. Most importantly, methods based on PCR, flowcytometry, cytoplasmic enzymes and circulating tumor antigens cannot provide essential morphological information confirming the structural integrity underlying metastatic potential of the presumed CTC and thus constitute functionally less reliable surrogate assays than the highly sensitive imaging methods embodied, in part, in this invention.
[0017] Detection of intact tumor cells in blood provides a direct link to recurrent metastatic disease in cancer patients who have undergone resection of their primary tumor. Unfortunately, the same spreading of malignant cells continues to be missed by conventional tumor staging procedures. Recent studies have shown that the presence of a single carcinoma cell in the bone marrow of cancer patients is an independent prognostic factor for metastatic relapse (Diel I J, Kaufman M, Goerner R, Costa S D, Kaul S, Bastert G. Detection of tumor cells in bone marrow of patients with primary breast cancer: a prognostic factor for distant metastasis. J Clin Oncol, 10:1534-1539, 1992). But these invasive techniques are deemed undesirable or unacceptable for routine or multiple clinical assays compared to detection of disseminated epithelial tumor cells in blood.
[0018] An alternative approach incorporates immunomagnetic separation technology and provides greater sensitivity and specificity in the unequivocal detection of intact circulating cancer cells. This simple and sensitive diagnostic tool, as described (U.S. Pat. No. 6,365,362; U.S. Pat. No. 6,551,843; U.S. Pat. No. 6,623,982; U.S. Pat. No. 6,620,627; U.S. Pat. No. 6,645,731; WO 02/077604; WO03/065042; and WO 03/019141) is used in the present invention to provide a preclinical animal model to enumerate CTC's.
[0019] The assay depends upon the acquisition of a preserved blood sample from a patient. The blood sample from a cancer patient (WO 03/018757) is incubated with magnetic beads, coated with antibodies directed against an epithelial cell surface antigen as for example EpCAM. After labeling with anti-EpCAM-coated magnetic nanoparticles, the magnetically labeled cells are then isolated using a magnetic separator. The immunomagnetically enriched fraction is further processed for downstream immunocytochemical analysis or image cytometry, for example, in the CellTracks® System (Veridex LLC, NJ). The magnetic fraction can also be used for downstream immunocytochemical analysis, RT-PCR, PCR, FISH, flowcytometry, or other types of image cytometry.
[0020] The CellTracks® System utilizes immunomagnetic selection and separation to highly enrich and concentrate any epithelial cells present in whole blood samples. The captured cells are detectably labeled with a leukocyte specific marker and with one or more tumor cell specific fluorescent monoclonal antibodies to allow identification and enumeration of the captured CTC's as well as unequivocal instrumental or visual differentiation from contaminating non-target cells. This assay allows tumor cell detection even in the early stages of low tumor mass. The embodiment of the present invention is not limited to the CellTracks® System, but includes any isolation and imaging protocol of comparable sensitivity and specificity.
[0021] Currently available preclinical protocols have not demonstrated a consistently reliable means for repetitively monitoring CTC's in assessing metastatic breast cancer (MBC) progression. The development of a reliable mouse model to assess diagnostic and therapeutic advancements in cancer research would provide a means to further research development in these areas. Thus, there is a clear need for accurate detection of cancer cells with metastatic potential, not only in MBC but in metastatic cancers in general. Moreover, this need is accentuated by the need to select the most effective therapy for a given patient.
[0022] The inability to repetitively monitor CTC's in the small blood volumes available in pre-clinical animal models of breast and other cancers has restricted their use to analysis of samples obtained from terminal blood draws. As a consequence, the study of temporal changes in CTC's during tumor progression and therapy in a living animal model, such as in mice, as not been established. However, using this technology to serially assay CTC's in mice would permit integration of CTC's assessments into pre-clinical as well as clinical studies. Further characterization of specific molecular markers on these cells would permit early development of “companion” diagnostic assays for targeted therapies, which would accelerate translation of new assay protocols into clinical trials in patients and ultimately into clinical practice.
SUMMARY OF THE INVENTION
[0023] The present invention provides a method and means for preclinical modeling of cancer metastasis in xenograft mice, incorporating clinical analysis tools such as the CellTracks® System, and is based upon the absolute number, change, or combinations of both of circulating epithelial cells in patients with metastatic cancer. The system immunomagnetically concentrates epithelial cells, fluorescently labels the cells, identifies and quantifies CTC's for positive enumeration in zenograft tumor models of human breast cancer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 : CellTracks® fluorescent analysis profile used to confirm objects captured as human tumor cells. Check marks signify a positive tumor cell based on the composite image. Composite images are derived from the positive selection for Epithelial Cell Marker (EC-PE) and for the nuclear dye (NADYE). A negative selection is also needed for the leukocyte marker (L-APC) and for control (CNTL).
[0025] FIG. 2 : Quantification of human breast cancer cells in mouse blood samples. MDA-MB-231 human breast cancer cells without or with stable transduction of GFP were added to 100 μl blood samples from mice without tumor xenografts. Samples were fixed, and epithelial cells were enriched by immunomagnetic bead isolation using an antibody to epithelial cell adhesion molecule. Recovered cells then were stained with an antibody to cytokeratin (8, 18, and 19) to identify epithelial cells and distinguish them from leukocytes stained with CD45. Nucleated cells were identified by staining with the fluorescent nucleic acid dye 4,2-diamidino-2-phenylindole dihydrochloride (DAPI). GFP on cancer cells was detected in the FITC channel. Representative images of recovered breast cancer cells are shown.
[0026] FIG. 3 : Quantification of human breast cancer cells in mouse blood samples. Terminal blood samples from mice bearing xenografts of MDA-MB-231 human breast cancer cells were obtained by cardiac puncture and analyzed for CTC. Numbers of CTC are plotted versus tumor volumes measured by calipers.
[0027] FIG. 4 : Serial analysis of CTC in mice. Mice were implanted with orthotopic tumor xenografts of SUM-159 (A) or SKBR-3 (B) human breast cancer cells, and CTC in approximately 100 μl blood samples were measured by cardiac puncture at approximately weekly intervals until mice were euthanized because of tumor burden. CTC data were normalized to 100 μl volume and plotted against tumor volume for individual. Mean numbers of CTC were significantly greater on day 30 as compared with prior days (p<0.05).
DETAILED DESCRIPTION OF THE INVENTION
[0028] While any effective mechanism for isolating, enriching, and analyzing CTC's in blood is appropriate, one method for collecting circulating tumor cells combines immunomagnetic enrichment technology, immunofluorescent labeling technology with an appropriate analytical platform after initial blood draw. The associated test has been shown to have the sensitivity and specificity to detect these rare cells in a sample of whole blood and to investigate their role in the clinical course of the disease in malignant tumors of epithelial origin. From a sample of whole blood, rare cells are detected with a sensitivity and specificity to allow them to be collected and used in modeling disease progression in an animal model.
[0029] Circulating tumor cells (CTC's) have been shown to exist in the blood in detectable amounts. This created a tool to investigate the significance of cells of epithelial origin in the peripheral circulation of cancer patients (Racila E., Euhus D., Weiss A. J., Rao C., McConnell J., Terstappen L. W. M. M. and Uhr J. W., Detection and characterization of carcinoma cells in the blood, Proc. Natl. Acad. Sci. USA, 95:4589-4594 (1998)). This study demonstrated that these blood-borne cells might have a significant role in the pathophysiology of cancer. Having a detection sensitivity of 1 epithelial cell per 5 ml of patient blood, the assay incorporated immunomagnetic sample enrichment and fluorescent monoclonal antibody staining followed by flowcytometry for a rapid and sensitive analysis of a sample.
[0030] The CellSearch™ System (Veridex LLC, NJ) previously has been used to isolate and enumerate circulating epithelial tumor cells from human blood samples 2 . This is an automated system that enriches for epithelial cells using antibodies to epithelial-cell adhesion molecule coupled to magnetic beads. Isolated cells then are stained with the fluorescent nucleic acid dye 4,2-diamidino-2-phenylindole dihydrochloride (DAPI) to identify nucleated cells. Recovered cells subsequently are stained with fluorescently labeled monoclonal antibodies to CD45 (APC channel) and cytokeratin 8, 18, 19 (PE channel) to distinguish epithelial cells from leukocytes. Nucleated epithelial cells then are quantified as circulating tumor cells. There is an additional fluorescence channel for FITC that is not part of the standard CellSearch™ assay and may be used for further characterization of tumor cells.
[0031] As shown in Example 1, the assay was further configured to an image cytometric analysis such that the immunomagnetically enriched sample is analyzed by the CellTracks® System. This is a fluorescence-based microscope image analysis system, which in contrast with flowcytometric analysis permits the visualization of events and the assessment of morphologic features to further identify objects.
EXAMPLE 1
Enumeration of Circulating Cytokeratin Positive Cells
[0032] The CellTracks® System refers to an automated fluorescence microscopic system for automated enumeration of isolated cells from blood. The system contains an integrated computer controlled fluorescence microscope and automated stage with a magnetic yoke assembly that will hold a disposable sample cartridge. The magnetic yoke is designed to enable ferrofluid-labeled candidate tumor cells within the sample chamber to be magnetically localized to the upper viewing surface of the sample cartridge for microscopic viewing. Software presents suspect cancer cells, labeled with antibodies to cytokeratin and having epithelial origin, to the operator for final selection.
[0033] While isolation of tumor cells for the CellTracks® System can be accomplished by any means known in the art, one embodiment uses immunomagentic enrichment for isolating tumor cells from a biological sample. Epithelial cell-specific magnetic particles are added and incubated for 20 minutes. After magnetic separation, the cells bound to the immunomagnetic-linked antibodies are magnetically held at the wall of the tube. Unbound sample is then aspirated and an isotonic solution is added to resuspend the sample. A nucleic acid dye, monoclonal antibodies to cytokeratin (a marker of epithelial cells) and CD 45 (a broad-spectrum leukocyte marker) are incubated with the sample. After magnetic separation, the unbound fraction is again aspirated and the bound and labeled cells are resuspended in 0.2 ml of an isotonic solution. The sample is suspended in a cell presentation chamber and placed in a magnetic device whose field orients the magnetically labeled cells for fluorescence microscopic examination in the CellTracks® System. Cells are identified automatically in the CellTracks® System and candidate circulating tumor cells presented to the operator for checklist enumeration. An enumeration checklist consists of predetermined morphologic criteria constituting a complete cell.
[0034] Cytokeratin positive cells are isolated by immunomagnetic enrichment using a 7.5 ml sample of whole blood from humans. Epithelial cell-specific immunomagnetic fluid is added and incubated for 20 minutes. After magnetic separation for 20 minutes, the cells bound to the immunomagnetic-linked antibodies are magnetically held at the wall of the tube. Unbound sample is then aspirated and an isotonic solution is added to resuspend the sample. A nucleic acid dye, monoclonal antibodies to cytokeratin (a marker of epithelial cells) and CD 45 (a broad-spectrum leukocyte marker) are incubated with the sample for 15 minutes. After magnetic separation, the unbound fraction is again aspirated and the bound and labeled cells are resuspended in 0.2 ml of an isotonic solution. The sample is suspended in a cell presentation chamber and placed in a magnetic device whose field orients the magnetically labeled cells for fluorescence microscopic examination in the CellTracks® System. Cells are identified automatically in the CellTracks® System; control cells are enumerated by the system, whereas the candidate circulating tumor cells are presented to the operator for enumeration using a checklist as shown in FIG. 1 .
EXAMPLE 2
In Vitro Recovery of Human Epithelial Cells
[0035] To accomplish this, 500 MDA-MB-231 breast cancer cells were spiked into 100 μl blood samples collected from mice without tumors. Since the clinical version of the assay requires blood be drawn into a proprietary vacuum tube, such as the CellSave tube, containing both an anticoagulant and a preservative, a proportionately reduced amount of CellSave solution was added to the specimens. The spiked specimens were then prepared, the CTC quantified and the percent recovery calculated. As a positive control, additional samples using MDA-MB-231 cells stably transduced with GFP were prepared. Fluorescence from GFP was detected in an open channel (FITC) of the system to confirm that all cells quantified as epithelial cells corresponded with 231-GFP cells added to mouse blood. As a negative control, mouse blood samples without cancer cells were collected, processed in an identical manner and analyzed. Of the 500 cells added to mouse blood (n=4 samples), 482-526 cells per specimen were recovered, which is within the range of the dilution error for spike-in experiments at this concentration ( FIG. 2 ). For samples using 231-GFP cells, all cells identified as epithelial cells also expressed GFP, verifying that these were human breast cancer cells and not contaminating murine epithelial cells. No epithelial cells were recovered from normal mouse blood, confirming the specificity of the assay.
EXAMPLE 3
Recovery of CTC from Xenografts in Mice
[0036] The preferred method to serially monitor CTC's in mouse models of human breast cancer incorporates the use of the CellTracks® System. As previously discussed, the system uses immunomagnetic isolation of epithelial cells from blood and immunofluorescent staining to further differentiate epithelial cancer cells from leukocytes. Because the CellTracks® system was originally developed to process 7.5 to 30 ml human blood samples, it is necessary that human epithelial breast cancer cells could be reliably recovered from small volumes of mouse blood using this assay (see Example 2).
[0037] The system was used to identify CTC's that spontaneously intravasate into the circulation from orthotopic tumor xenografts of MDA-MB-231 cells. 0.7 to 1 ml blood samples were collected from each mouse by puncture of the left ventricle when animals were euthanized for tumor burden at 10 weeks. Total numbers of CTC's ranged from approximately 100 to 1000 cells per ml of blood ( FIG. 3 ). No CTC's were recovered from blood samples collected from mice without tumor xenografts (data not shown). The number of CTC's did not correlate with size of the primary tumor. These data suggest that numbers of CTC's reflect the underlying biology of various primary tumors, which is consistent with previous studies showing that MDA-MB-231 cells contain subpopulations with differing metastatic potential. Using the same method, CTC's were also detectable in mice with tumor xenografts of MCF-7, MCF-7 cells stably transfected with fibroblast growth factor (FGF), SUM-159, and SKBR-3 cell-lines.
[0038] While the system was successful in detecting CTC's using cardiac puncture to collect blood, this procedure is invasive compared to other sites of blood sampling in mice. One aspect of the present invention is to repetitively draw blood samples for analysis of CTC's, blood samples from the lateral tail vein and retro-orbital venous plexus and thereby avoid the invasive nature of cardiac puncture. In mice with or without orthotopic MDA-MB-231 tumor xenografts were compared to direct cardiac sampling. No epithelial cells were detected in any of the lateral tail vein samples, independent of the presence of a tumor xenograft. One possible explanation for the failure to detect CTC's in tumor-bearing mice was the small volume of blood (≦25 μl) that could be collected from the lateral tail vein. Although larger volumes of blood (50-75 μl) could be obtained from the retro-orbital venous plexus, 3 of 3 blood samples from this site contained epithelial cells (5-500 cells) in mice without tumors. These contaminating cells were normal murine epithelial cells dislodged by the microcapillary tube during blood collection. Thus sampling via the retro-orbital route would make it impossible to reliably identify CTC in tumor-bearing mice. By comparison, there were no CTC's in blood samples obtained by cardiac puncture in mice without tumor xenografts, but CTC's could be detected in blood obtained via left ventricle cardiac puncture in mice with MDA-MB-231 xenografts.
EXAMPLE 4
Temporal Analysis of CTC's in Mice
[0039] After validating the assay and route of blood collection, the feasibility of detecting temporal changes in CTC's was investigated using mice implanted with orthotopic tumor xenografts of SUM-159 (n=3) or SKBR-3 (n=4) cells. 75 to 100 μl blood samples were collected approximately once per week for 1 month until mice were euthanized because of tumor burden. MDA-MB-231 and SKBR-3 human breast cancer cells were cultured in DMEM with 10% fetal bovine serum, 1% L-glutamine, and 0.1% penicillin/streptomycin. SUM-159 cells were cultured in Ham's F12 medium (Invitrogen) supplemented with 5% fetal bovine serum (FBS), 5 μg/ml insulin, 1 μg/ml hydrocortisone, and 0.1% penicillin/streptomycin. Cells were maintained at 37° C. in a 5% CO 2 incubator. For selected experiments, MDA-MB-231 cells were transduced with the lentiviral vector pSico to establish cells that stably express GFP. Efficiency of transduction was 100%, as determined by phase-contrast and fluorescence microscopy.
[0040] In producing tumor xenografts in mice, 5 to 6 week old female Ncr nude (Taconic) or SCID (Jackson) mice were used. Human breast tumor xenografts from cell lines, 1×10 6 cells were injected orthotopically into bilateral inguinal mammary fat pads of mice by methods know in the art. For tumor xenografts with clinical isolates of human breast cancer cells, mice were implanted with 1-5×10 5 cells in the fourth inguinal mammary fat pad. Mice implanted with clinical breast cancer isolates also received a subcutaneous pellet of 60-day sustained release 17-β-estradiol (Innovative Research of America). Volumes of tumors were quantified as the product of caliper measurements in two dimensions and calculated by the equation: width (mm)×width (mm)×length (mm)×0.52. For serial studies of CTC, blood samples were collected from the left ventricle at approximately weekly intervals as shown in the figure legend.
[0041] Assay results show low levels of CTC's (0-7 cells) in earlier samples (days 8-23) ( FIG. 4 ), with numbers of CTC's increasing significantly on day 30 in 6 of 7 mice (26-55 cells) (p<0.05), corresponding to an increase in tumor volume. These studies establish that the assay can be used successfully for serial studies of CTC's in mouse models of breast cancer.
[0042] For all CTC's measured in mice implanted with xenografts, primary breast cancer cells were obtained from patient biopsy specimens. Blood samples (200 μL-800 μL) were collected via cardiac puncture at the time animals were euthanized because of tumor burden. Breast cancer cells from 6 different patients formed tumors in mice, and all of these tumors produced CTC's. Numbers of CTC's ranged from 4-805 cells per ml of blood with a mean value of 118 cells ±67 (n=6). Notably, none of these animals had overt or histologically detectable metastases (data not shown), suggesting that the majority of CTC's produced by primary clinical specimens may not be capable of forming metastases in either mice or in humans. These data show that xenografts of clinical breast cancer isolates can produce CTC's in mice and therefore provide a model system for investigating properties and subpopulations of human breast cancer cells involved in metastasis.
[0043] While certain of the preferred embodiments of the present invention have been described and specifically exemplified above, it is not intended that the invention be limited to such embodiments. Various modification may be made thereto without departing from the spirit of the present invention, the full scope of the improvements are delineated in the following claims. | The CellTracks® System provides a system to enumerate CTC's in blood. The system immunomagnetically concentrates epithelial cells, fluorescently labels the cells and identifies and quantifies CTC's. The absolute number of CTC's detected in the peripheral blood tumor load is, in part, a factor in prediction of survival, time to progression, and response to therapy. Pre-clinical studies of circulating tumor cells (CTC's) have been limited by the inability to repetitively monitor CTC's in animal models. The present invention provides a method to enumerate CTC's in blood samples obtained from living mice, using a protocol similar to an in vitro diagnostic system for quantifying CTC's in patients. Accordingly, this technology can be adapted for serial monitoring of CTC's in mouse xenograft tumor models of human breast cancer. | 6 |
This application claims priority to German Utility Model Application No. 298 11405.4, filed Jun. 25, 1998, which is incorporated herein by reference.
FIELD OF THE INVENTION
The invention relates to a drilling implement for drilling holes in the ground, having a mounting, a drill drive, which is arranged displaceably on the mounting, for drilling tools, such as drill tubes or drill rods, a linear magazine, which is arranged on the mounting, in which the drilling tools can be stored in a magazine in a plane parallel to the mounting and which can be displaced in this plane by means of a drive device, and a clamping device for the selective rotational fixing of the fitted drill string and a drill tube which can be connected thereto and is arranged in the drilling axis.
BACKGROUND OF THE INVENTION
Hitherto, drill rods have been stored and handled by means of various magazines and magazine forms. For example, document DE 40 30 525 C2, which portrays the generic device, has disclosed a rod magazine for a rock drill machine, which magazine has two receiving devices which are spaced apart, are arranged on a mounting which supports a drill drive and each have a guide fork for accommodating drill stems in a parallel plane to the mounting. By means of hydraulic cylinders, the receiving devices can be displaced toward the drilling axis until the drill stem which is to be removed from the receiving device bears against a guide surface and is released from the receiving device. Then, it is screwed to the drill string. These movements are controlled with the aid of contactless switches with electronic switching elements which interact with switching lugs. Such a complex arrangement of sensors does not rule out the possibility of incorrect functional sequences, owing to the sensitivity of the switching elements to the severe operating conditions involved in the use of a drilling implement.
DE 297 03 271 U1 has disclosed a drilling implement with a rotable drum magazine for drill tubes which is arranged on a mounting, in which implement a handling device is provided for removing the drill tubes from the drum magazine; this handling device has a telescopic gripper arm with a gripper. However, a considerable outlay on control engineering is required for the fully mechanized actuation of the handling device.
SUMMARY OF THE INVENTION
Therefore, the invention is based on the object of improving a drilling implement of the type described above in such a manner that the rod can be inserted from a rod magazine into the drill string or the rod can be removed from the drill string and stored in the rod magazine, without the need to use the sensor devices which have hitherto been customary and are susceptible to faults in order to control the sequence.
According to the invention, the object is achieved by the fact that, in the drilling implement outlined above, stops are provided as mechanical travel-limiting means when the drill tubes are being positioned in respective functional positions.
Positioning the drill tubes against mechanical travel-limiting means obviates the need for a control device with a high risk of the sensors failing. Nevertheless, an operator of such a drilling implement can carry out the magazining and transfer operations without difficulty and without significantly increasing the nonproductive times when drilling.
Advantageous configurations of the invention are given in the subclaims.
Expediently, the stops are provided in the drive device for the linear magazine and fix magazining and transfer positions for the drill tubes. The stops are, for example, the limit positions of movement paths of piston-cylinder units of the drive device, so that the linear magazine is ineluctably arranged in the desired positions.
Furthermore, it is advantageous if a stop is formed, as a rod support, on a stationary rod chuck of the clamping device. As a result, a limit position is defined directly by a drill tube which is arranged in a longitudinal axis of the drilling string or in the drilling axis and is then screwed to the drill string.
If different receiving contours can be set on the rod support, in order to match different diameters of drill tubes, the drilling implement can be employed universally by changing these contours.
This change in the contours can be carried out by means of an adjustment device for movable contours. As an alternative, rod supports with different receiving contours may be fitted to the rod chuck as desired.
In an advantageous embodiment, the linear magazine has two spaced-apart receiving devices for the drill tubes.
Tube holders for clamping a drill tube in a transfer position in the linear magazine may be arranged on the receiving devices. By means of the tube holders, the front drill tube may in each case be clamped onto the receiving device and can be conveyed into the transfer position in the drilling axis, where it can be screwed to the drill string.
According to an advantageous refinement of the invention, the linear magazine contains a preloading device which presses the drill tubes which are stored in the magazine toward the drill tube which is clamped in the tube holders. This simplifies the functional sequence involved in removing a drill tube from the liner magazine.
If the linear magazine can be displaced with respect to the mounting by way of its receiving devices and, by means of respective limit stops on the movement paths of the drive devices, can be positioned in different, in particular three, functional positions, an operator can move the magazine into these positions in a simple manner.
Expediently, the receiving devices contain holding forks, which receive and guide the stored drill tubes in a holding fork opening.
The universal usability of the drilling implement is further enhanced by the fact that adapter elements can be fixed to the holding forks in order to adapt to different drill-tube diameters.
The fact that the translational movement of the receiving devices and/or of the holding forks is synchronized by hydraulic or mechanical synchronization of the two drive devices means that the drill tubes are always moved exactly into the drilling axis, without the operator having to act specifically to ensure this.
For simple adaptation to different drill-tube diameters, it is also possible to fit spacer rings to the drive devices.
If, according to a further configuration of the drilling implement according to the invention, it is possible to adjust the positioning of a means for attaching the drive device to a support of the mounting, it is possible, in a simple manner, to adapt the linear magazine to different transmissions with different distances between the drilling axis and the mounting.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in more detail below on the basis of an exemplary embodiment of a drilling implement according to the invention and with reference to drawings, in which:
FIG. 1 : shows an overall view of a drilling implement with a rod magazine according to the invention;
FIG. 2 : shows a side view of the drilling implement shown in FIG. 1, in the direction of the drilling axis;
FIGS. 3 to 14 : each show two views, corresponding to FIG. 1 and FIG. 2, of different movement positions of the drilling implement when drill tubes are being removed from the magazine;
FIG. 15 : shows a side view of the drilling implement in accordance with FIG. 1, at its chuck-side end;
FIG. 16 : shows a plan view of a rod support;
FIG. 17 : shows an axial plan view of the drilling implement in accordance with FIG. 1;
FIG. 18 : shows a view in accordance with FIG. 17 of the drilling implement, with the linear magazine in an advancing position; and
FIG. 19 : shows an enlarged version of the same view of the drilling implement as that shown in FIG. 18 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A drilling implement 1 has a mounting 2 , on which a drill transmission 3 of a drill drive for a drill rod 4 is mounted in a longitudinally displaceable manner by means of a carriage 5 . Only those components of the drilling implement 1 which are required in order to describe the invention are shown, and the implement may be arranged and positioned on a drill carriage, as described, for example, in DE-A 38 19 537. A rod magazine 6 for receiving and storing drilling tools 7 , such as drill tubes, drill stems or rod stands is arranged on the mounting 2 . Naturally, the drilling implement is suitable for making holes in any type of ground, such as soil, lithosol or rock.
A drill string coupling, which is also known as the transmission-side tube nipple 10 , is attached to an output shaft 8 of the drill transmission 3 , and therefore coaxially with respect to a drilling axis 9 . At its end 11 which is on the drilled-hole side, the mounting 2 has a stationary first rod chuck 12 with a rod support 13 , which forms a mechanical travel-limiting means or a stop for a drill tube 7 . The rod support 13 is a plate which is detachably connected to the chuck 12 (cf. in particular FIG. 15) and, due to its contour 30 (cf. FIG. 16 ), centers the rod or drill tube 7 in the drilling axis 9 . Depending on the diameter of the drill tubes 7 used, it is necessary to use a suitable rod support 13 with the associated contour 30 (FIG. 16 shows the rod support 13 with four contours, representing four rod supports for the different diameters). FIG. 15 shows a drill tube 7 which is held in the holding fork 18 before it is placed in the rod support 13 .
Between this stationary first chuck 12 and a rotable second chuck 14 , which is arranged at a distance from the first chuck in the direction of the drilling axis, there is a rod-breaking cylinder 15 which, by the way in which it is coupled, is able to rotate the first chuck 12 relative to the second chuck 14 , by adopting a retracted position and an extended position. The second chuck 14 contains a tube guide 16 for centering and guiding the drill string or drill rod 4 .
The rod magazine 6 has a receiving device 17 for the drilling tools or drill tubes 7 , with two U-shaped holding forks 18 which are spaced apart from one another (cf. FIG. 2) and are arranged in such a way that their openings 19 for the drill tubes 7 , which openings extend in linear fashion, open toward the drilling axis 9 of the drill transmission 3 and intersect this axis. Thus, the drill tubes 7 , which are stored in the rod magazine 6 , also known as linear magazine, are arranged next to and parallel to one another in a plane which is parallel to the drilling axis 9 . Axial guides, such as for example guide plates 31 , are arranged on the holding forks 18 , which plates guide the drill tubes 7 axially in the rod magazine 6 . They may have a run-in slope 32 . The two holding forks 18 are arranged on a transmission-side support 20 or on a drilled-hole-side support 21 which is spaced apart from the transmission-side support, which supports are attached to the mounting 2 via a longitudinal rail 22 and can be displaced perpendicularly with respect to the drilling axis 9 by way of guides 23 provided on the supports 21 , 22 .
The holding forks 18 are driven by means of respective drive devices 24 , such as piston and cylinder devices, which have, for example, a tandem cylinder, two cylinders connected in series or a controlled-displacement cylinder. The piston and cylinder devices are operatively connected between the support 20 or 21 and the respective holding fork 18 , so that the holding forks 18 can be displaced, and in particular can adopt three positions, which also represent the position of the rod magazine and are described in more detail below. The movements of the two holding forks 18 between the three positions (starting position in accordance with FIGS. 3A and 3B, transfer position in accordance with FIGS. 4A and 4B, for example, advancing position in accordance with FIGS. 7A and 7B, for example) are mechanically limited by means of the tandem cylinders or by means of the series connection of two cylinders. When the rod magazine 6 , together with the holding forks 18 , is in the starting position, both sides of the tandem cylinder or both series cylinders are extended. If the rod magazine 6 , together with the holding forks 18 , is in the transfer position, the tandem cylinders are retracted on both sides (or both series-connected cylinders are retracted) . If the rod magazine 6 , together with the holding forks 18 , is in the advancing position, the first side of the tandem cylinder is extended (or the first cylinder of the series cylinders is extended) . Thus the displacement paths of the two holding forks 18 are mechanically limited by means of the limit positions of the cylinders of the drive devices 24 .
Synchronous translational movement of the two holding forks 18 is achieved by means of a hydraulic or mechanical synchronization of the two drive devices 24 . Each holding fork 18 has a tube holder 25 for a drill tube 7 which is situated in the magazine or holding fork opening 19 , at the most forward position, or removal position. The tube holder 25 comprises one or, for example, two opposite pressure pistons 26 which can be actuated hydraulically, can move toward one another, in a closed position clamp the drill tube 7 between them and in an open position are able to release this tube again.
The receiving device 17 or the two holding forks 18 may have a preloading device (not shown) which presses the other drill tubes 7 stored in the magazine toward the drill tube 7 which is being held in the tube holders 25 .
The sequence of operations involved in manipulation of the individual drilling tools 7 or rod stands when the drill string 4 is being used to carry out the drilling operation and during the subsequent pulling of the drill string, and therefore during the associated insertion and removal of the individual drilling tools 7 into and from the magazine, is described with reference to FIGS. 3 to 14 .
FIGS. 3A and 3B shows the drilling implement 1 in a starting position. The rod magazine 6 , together with the two holding forks 18 and the stored drill tubes 7 , is in a position which is remote from the mounting 2 and, with regard to the mounting 2 which is illustrated in the horizontal position, is also known as the upper position. The tube holders 25 hold the drill tube 7 which is situated at the furthest forward or lowest position in the holding fork opening 19 clamped in place. The first chuck 12 is open, while the second chuck 14 is closed. The drill transmission 3 , together with its attachments, such as the tube nipple 10 , has been moved out of the area of the rod magazine 6 .
The rod magazine 6 is then displaced toward the mounting 2 (downward as seen in the figures) until the rod magazine 6 or the drill tube 7 bears against the stop 13 (cf. FIGS. 4 A and 4 B). The first chuck 12 is closed.
Then (cf. FIGS. 5 A and 5 B), the transmission-side tube nipple 10 is screwed to the drill tube 7 which is arranged in a rotationally fixed position in the drilling axis 9 , by means of suitable, superimposed advance and rotational movements of the drill transmission 3 . The tube holders 25 continue to hold the drill tube 7 securely in the holding fork opening 19 . The drill transmission 3 has moved into a first intermediate position, in which the drill tube 7 , which has been screwed to the tube nipple 10 , is still arranged beneath the rod magazine 7 , that end of the drill tube 7 which faces the drill string 4 lying securely in the first chuck 12 . This represents the transfer position of the rod magazine 6 and of the drill tube 7 .
The tube holders 25 are opened (FIGS. 6A and 6B) and the rod magazine 6 is moved upward by one tube position, i.e. by the distance which approximately corresponds to the diameter of one drill tube 7 (FIGS. 7 A and 7 B). Since the tube holders 25 are open, the other drill tubes 7 which are stored in the magazine are not moved with it, but rather remain bearing against one another due to the preloading device.
The tube holders 25 are closed and clamp the next drill tube 7 ′, which is adjacent to the drill tube 7 arranged in the drilling axis 9 (FIGS. 8 A and 8 B). The rod magazine 6 is moved upward into the starting position, taking all the drill tubes situated in the holding fork opening with it. Then, by means of superimposed advance and rotational movements of the drill transmission 3 (FIGS. 9 A and 9 B), the drill tube 7 is screwed to the drill string 4 . The drill transmission 3 in the process moves into a second intermediate position.
The second chuck 14 is opened (FIGS. 10 A and 10 B), and the drill rod is drilled by being driven by means of the drill transmission 3 . In the process, the drill transmission 3 moves one stand length into its drilled-hole-side limit position (FIGS. 11 A and 11 B). Then, the first and second chucks 12 and 14 are closed, thus clamping the drill tube 7 which has drilled down, as well as the tube nipple 10 which has been screwed to it (FIGS. 12 A and 12 B). Movement of the breaker cylinder 15 loosens the screw connection. The first chuck 12 is opened, and, by means of a superimposed return and unscrewing movement of the drill transmission 3 , the transmission-side tube nipple 10 is unscrewed and removed from the drill string 4 (FIGS. 13 A and 13 B). The drill transmission 3 moves back into its starting position (cf. FIGS. 14 A and 14 B), which corresponds to the position illustrated in FIG. 1 .
In order for the following drill tubes 7 from the rod magazine 6 also to be fitted to the drill string 4 , the procedure described above is repeated until sufficient drill tubes have been attached.
If, after the rod has been drilled down and the hole has been made in the ground, the drill string or the drill tubes are to be pulled out again, the procedure described is carried out in the reverse order.
Various drill transmissions 3 may be arranged on the drilling implement according to the invention and may differ in terms of the distance 33 between the drilling axis 9 and the mounting 2 . To adapt this changeable distance 33 , there is provision for it to be possible to change the position of a height-fixing means 34 on the supports 20 , 21 on which the drive devices 24 act and to secure this means, for example by means of plugs or screws. In this way, the holding forks 18 can be positioned correctly via the respective drive cylinders (tandem or series cylinders).
To adapt the drilling implement to different diameters of drill tubes 7 used, there is provision for the holding forks 18 to be adapted to the particular rod diameter which is to be accommodated by means of adapter elements, such as for example screw-on or plug-on guide strips 35 (cf. FIG. 17 ), in that these strips 35 narrow the holding fork openings 19 .
The displacement path of the rod magazine 6 and of the holding forks 18 is adapted to different rod diameters by means of spacer rings 36 , 37 , which are arranged on the piston rods 38 and 39 , respectively, of the cylinders (cf. FIG. 17 ). In this way, according to a reduction in diameter from a maximum diameter to a minimum diameter, the distance over which the cylinder which, via the holding forks 18 , moves the drill tube 7 , together with the magazine 6 , into the drilling axis 9 can move is reduced, and the distance over which the cylinder which moves the holding forks 18 into the top position (starting position in accordance with FIGS. 3A and 3B, for example) is increased. A tandem cylinder as the drive device 24 is illustrated in FIG. 19 . | The invention relates to a drilling implement for drilling holes in the soil. In known drilling implements, drilling tools, such as drill tubes or drill rods, are stored and handled via magazines and magazine forms which require a considerable outlay on sensors and control engineering in order to position the drilling tools. In the drilling implement according to the invention, there is provision for stops to be provided as mechanical travel-limiting mechanisms when the drill tubes are being positioned in respective functional positions. This obviates the need for sensor and control devices which are expensive and susceptible to faults. | 4 |
BACKGROUND
[0001] U.S. Pat. No. 5,178,215 serves as a starting point for the departure made by the present invention. The disclosure of U.S. Pat. No. 5,178,215 is intended to be incorporated herein by reference and includes a general discussion of an existing rotary blowout preventer which is fluid actuated to grip a drill pipe or kelly, and the controlled circulation of a fluid to lubricate and cool bearings and seals, and to filter particulate matter.
[0002] These existing rotary blowout preventers have an annulus between an outer housing and a rotary housing. Such systems use rather large bearings which require a rather large clearance. Such an arrangement has positive effects but also results in “wobbling” between the rotary housing and the outer housing. The wobbling creates heat, “nibbles” the seals, etc. A fluid is introduced into and circulates through the annulus between the outer housing and the rotary housing to cool the seal assemblies, the bearings and to counteract heat generated by contact between the seals and the rotary housing (wellhead fluid temperatures may normally be about 200° F., and during rotation, without cooling, the temperature would readily increase to about 350° F. and destroy a seal in a relatively short time). The circulated fluid also removes foreign particulate matter from the system. Pumps are used to maintain a fluid pressure in the annulus at a selected pressure differential above the well bore pressure.
[0003] The bearings in these rotary blowout preventers may normally operate at a temperature of about 250° F. Such bearings are subjected to a significant thrust load, e.g. 2,000 lbs.-force, due in part to an upward force created by well bore pressures and placed upon a packer assembly and a sleeve in the rotary housing. Such a thrust load will generate significant heat in a bearing rotating at, for example, 200 rpm. Heat, and heat over time, are important factors which may lead to bearing failure. For example, bearings may immediately fail if they reach temperatures of about 550° F. Even at temperatures of 250° F. a bearing may fail after a significant period of use, for example, twenty days of rotation at 200 rpm when subjected to a significant thrust load.
[0004] Such existing rotary blowout preventers are very functional at wellhead pressures up to 2000 psi. However, for reasons discussed herein, there are added challenges when wellhead pressures are in the range of, for example, 2500 psi to 5000 psi.
[0005] For example, as suggested, the continued and trouble free operability of such rotary blowout preventers is dependent, in part, upon the life of the seals and bearings within the rotary blowout preventer. The seals have a “pressure/velocity” or “pv” rating which may be used to predict the relative life of a seal given the pressure and velocity conditions to be borne by a seal. When considering “PV” rating, it is significant to note that a linear relationship does not exist between the life of a seal and the increases in pressure or rotational velocity to which a seal will be subjected. Rather, the life of the seal decreases exponentially as the pressure or rotational velocity to which the seal is subjected is increased.
[0006] As such, when well bore pressures increase to ranges from 2500 psi to 5000 psi, the loads, the wear and the heat exerted on seals and bearings within a rotary blowout preventer pose a greater challenge to the operations and life of the seals and bearings. This must be considered in the context of the fact that well bore operations may be shut down for maintenance work when significant wear of seals or bearings, significant “nibbling” of seals, or seal/bearing failure occurs. Such shut downs can significantly affect the profitability of well bore operations.
SUMMARY OF THE INVENTION
[0007] This rotary blowout preventer has a first and a second pressurized fluid circuit. Each of the fluid circuits are defined into and out of a stationary body and between the stationary body, a rotating body, and two seals. The first fluid circuit is physically independent from the second fluid circuit although they share a seal interface. A fluid is introduced into the first fluid circuit at a pressure responsive to the well bore pressure. A fluid is introduced into the second fluid circuit at a pressure responsive to and lower than the pressure of the fluid in the first circuit. Adjustable orifices are connected to the outlet of the first and second fluid circuits to control such pressures within the circuits. Such pressures affect the wear rates of the seals. The system can therefore control the wear rate of one seal relative to another seal. A thrust bearing is added to share the load placed upon the upper bearings. The thrust bearing is connected between the top end of a packer sleeve and the stationary body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIG. 1 is a sectional view of a rotary blowout preventer incorporating the invention(s).
[0009] [0009]FIG. 2 is a sectional view of the rotating body without the packer sleeve.
[0010] [0010]FIG. 3 is an enlarged view of the middle and upper seal carriers shown in FIG. 1.
[0011] [0011]FIG. 4 is a sectional view of the top closure.
[0012] [0012]FIG. 5 is a schematic view of a control system which may be used in the invention(s).
DETAILED DESCRIPTION
[0013] Referring to FIGS. 1 and 2, the rotating blowout preventer 8 generally includes a stationary body 10 which houses a rotating body 12 . The rotating body 12 includes a rotating housing 14 , a rotating housing cover plate 16 and a packer assembly 18 . The packer assembly 18 has a split keeper ring 20 , an outer packer 22 , an inner packer 24 and a packer sleeve 26 . The stationary body 10 generally includes a body 28 with a top closure 30 and a bottom closure flange 32 .
[0014] A lower bearing 34 is mounted between the stationary body 10 and the rotating body 12 in a cup 36 . An upper bearing 38 is mounted between the stationary body 10 and the rotating body 12 against a cup 40 . A bottom thrust bearing 42 is mounted between the stationary body 10 and the rotating body 12 on the bottom closure flange 32 .
[0015] A first or bottom seal carrier 44 is mounted between the stationary body 10 and the rotating body 12 and includes a groove for the mounting of a first seal 46 , which may, for example, be a seal of the type marketed by Kalsi Engineering, Inc. A bearing 48 , for example, a type marketed by Kaydon is mounted between the first seal carrier 44 and the rotating body 12 . A locking nut 50 a may be used for attaching the bottom closure flange 32 to the body 28 .
[0016] Packer adapters 52 and 54 are connected to the packer sleeve 26 . A packer-pulling sleeve 56 engages the upper end of the packer adapter 54 . A thrust bearing 58 has a lower end 60 connected to a top end 62 of the packer sleeve of the rotating body 12 , and an upper end 64 connected to a top closure 66 of the stationary body 10 . The lower end 60 of the thrust bearing 58 is rotatable. The top closure 66 is held in place by a top closure flange 68 and studs 70 . The thrust bearing 58 is mounted inside a bearing retaining ring 72 . The bearing retaining ring 72 has openings between the thrust bearing o-rings 74 and 76 for introduction, circulation and outlet of a cooling fluid as part of a thrust bearing cooling and lubricating circuit 75 . The thrust bearing 58 , may be a commercially available thrust cylindrical roller bearing or it may be custom built.
[0017] The body 28 defines an inlet orifice 80 and an outlet orifice 82 of a first fluid or actuating, lubricating, cooling and filtering circuit 81 . The first fluid circuit 81 is further defined by the annular space between the rotating body 12 and the stationary body 10 and cools, lubricates and filters the region between the rotating body 12 and the stationary body 10 including the lower bearing 34 and the upper bearing 38 . FIG. 2 shows surfaces 17 a and 17 b of the rotating housing cover plate 16 which help define the first fluid circuit 81 between the rotating body 12 and the second seal carrier 92 . FIG. 4 shows annular cup 40 and annular surfaces 31 a,b and c in top closure 30 which also define in part the first fluid circuit 81 . The first fluid circuit 81 loads first seal carrier 44 and one side of first seal 46 as well as second seal carrier 92 and one side of second seal 96 .
[0018] The rotating blowout preventer 8 has a second fluid or lubricating, cooling and filtering circuit 83 . The second fluid circuit 83 has an inlet orifice 84 and an outlet orifice 86 which may be tubular and which may be defined by the stationary body 10 such as by the body 28 and the top closure 30 and may be made, for example, by cross-drilled lines 88 a,b,c,d,e , & f in stationary body 10 and top closure 30 . The second fluid circuit 83 further has annular voids defined by the third seal carrier 94 itself, and between the third seal carrier 94 and annular channels 33 a and 33 b (FIG. 4) in top closure 30 . FIG. 2 shows surface 17 c of the rotating housing cover plate 16 which helps define the second fluid circuit 83 between the rotating body 12 and the third seal carrier 94 . The cross-drilled lines 88 b and 88 e may be isolated from the first fluid circuit by, for example, plugs 90 a and 90 b respectively.
[0019] As discussed above the annular voids defined intermediate top closure 30 and rotating housing cover plate 16 are for the mounting of a second or middle seal carrier 92 and a third or top seal carrier 94 (the first seal carrier 44 is placed in an annular void defined by rotating housing 14 and bottom closure flange 32 ). A second seal 96 is mounted in the second seal carrier 92 and a third seal 98 is mounted in the third seal carrier 94 . The first, second and third seal carriers 44 , 92 , 94 are preferably hydraulically balanced floating seal carriers for carrying seals 46 , 96 , 98 . Such seals may be, for example, seals of the type marketed by Kalsi Engineering, Inc.
[0020] Referring to FIG. 3 various seal or o-rings 100 a,b,c,d,e,f,g and h are mounted in grooves around the second and third seal carriers 92 and 94 , and the top closure 30 . Bearing 102 is mounted in the second seal carrier 92 and in the first fluid circuit 81 . Bearing 104 is mounted in the second fluid circuit intermediate the third seal carrier 94 and a bearing spacer 101 . As discussed above, annular voids are defined by the top closure 30 and/or by the second and third seal carriers 92 and 94 . These annular voids form part of the first and the second fluid circuits 81 and 83 .
[0021] The rotating blowout preventer 8 and the fluid circulation circuits may be operated as discussed below. This system is especially useful in well bore environments where the pressure of the well bore exceeds 2500 psi on up to and exceeding 5000 psi.
[0022] The description following in the next two paragraphs serves as an example of the implementation of the invention and is not intended to quantify any limits on the value of features expressed in terms of pressure or time. However, such quantified values may be individually or collectively claimed as a preferred embodiment of the invention.
[0023] A fluid for actuating, for cooling, for lubricating and for removing foreign particulate matter is introduced into the first fluid circuit 81 at a pressure P 1 . The pressure P 1 is at or about well bore pressure plus about 300 psi (i.e. P 1 ranges from 300 psi to 5300 psi depending upon well bore pressure). At the same time, a like or a similar fluid is introduced into the second fluid circuit 83 at a pressure P 2 in the range of about 35% to 65% of the pressure P 1 . The second seal 96 experiences a pressure differential from P 1 to P 2 and the third seal 98 experiences a pressure differential from P 2 to atmosphere (or to the pressure of the thrust bearing cooling circuit 75 ). The pressure P 2 may nominally be introduced into the second fluid circuit 83 at approximately one-half the pressure P 1 . Next, data may be gathered by one skilled in the rotating blow out preventer art relating to wear rates and conditions for bearings and seals within the rotary blowout preventer 8 . Then, such data may be used to empirically determine optimal pressure settings, pressure differentials and pressure changes to be made in response to variables such as changes in the well bore pressure in order to maintain the integrity of the seals and bearings. More specifically, it will be advantageous to control the pressure differentials such that the second seal 96 has a wear rate exceeding the wear rate of the third seal 98 . This is because if excessive wear is inflicted upon the second seal 96 prior to being inflicted upon the third seal 98 , a leak past the second seal 96 will create an increase in pressure in the second fluid circuit 83 as detected by controls such as pressure transducers, in the control system 110 . Then, the pressure increase detected in the second fluid circuit 83 may be used to infer or signal the possibility of the infliction of excessive wear on the third seal 98 (the timing of such an infliction of excessive wear on the third seal 98 being dependent upon a variety of variables such as well bore pressure, working rotational velocity, the current condition of the third seal 98 , etc.) thus prompting at least the consideration of maintenance operations. Accordingly, maintenance operations may be fore planned and fore scheduled prior to a leak past third seal 98 . Comparatively, the infliction of excessive wear on the third seal 98 prior to the infliction of excessive wear on the second seal 96 (or the infliction of excessive wear on the upper seal in the existing rotary blowout preventers) can result in a leak to atmosphere and an immediate shutdown or “kill” of well operations.
[0024] In a more specific example, if the well bore pressure is 4000 psi, then the pressure P 1 could be about 4300 psi, and the pressure P 2 could be nominally about 2150 psi (incidentally the pressure seen from above the third seal 98 could be about 60 psi). Then the pressures of the well bore, P 1 and P 2 can be detected (e.g., every fifty to one hundred milliseconds) in the control system 110 and the pressures P 1 and/or P 2 adjusted as suggested by empirical data or experience to, in anticipation of the infliction of excessive wear on a seal, cause the second seal 96 to incur excessive wear prior to the third seal 98 . As mentioned above, this sequence of events will suggest to operators that maintenance work should be planned and conducted within, and dependent upon operational variables, about six hours.
[0025] Referring to FIG. 5, a control system 110 which may be used with the rotary blowout preventer is shown. The control system 110 generally connects via line 112 to the inlet orifice 80 of the first fluid circuit 81 and via line 116 to the outlet orifice 82 of the first fluid circuit 81 . The control system 110 generally connects via line 114 to the inlet orifice 84 of the second fluid circuit 83 and via line 118 to the outlet orifice 86 of the second fluid circuit 83 . The control system 110 generally includes pumps 120 and 122 such as fixed displacement pumps for circulating a cooling and lubricating fluid; filters 124 and 126 for filtering the fluid fluid; and valves, for example, pinch valves, 128 , 130 , 132 and 134 . The valves may, for example, be used to create backpressure on the respective first and second fluid circuits 81 , 83 and to energize the floating seal carriers 46 , 96 , 98 by varying the orifice of the valves 128 , 130 , 132 , and 134 . The pressure within the circuits 81 , 83 may be independently adjusted or varied by other means, such as, for example, via pumps (not shown).
[0026] The thrust bearing 58 shares the thrust load, e.g. 2,000 lbs.-force, exerted by well bore pressure and placed upon the packer assembly 18 and consequently the load placed upon the lower and upper bearings 34 , 38 while allowing the rotable body 12 to rotate. Such results in lowering the heat on lower and upper bearings 34 , 38 and extending the life of same. By sharing the thrust load, “nibbling” of the first, second and third seals 46 , 96 , 98 may be decreased to extend the seal life of same. It is also advantageous to lubricate the thrust bearing 58 to counter the heat effects of the thrust load and rotation upon same. This may be accomplished, for example, by a thrust bearing cooling and lubricating circuit 75 which introduces the cooling fluid to the thrust bearing through the opening between the o-rings 74 and 76 .
[0027] It should be noted that reverse rotation may be utilized during use of the rotary blowout preventer 8 and the invention will be functional under such conditions.
[0028] In conclusion, therefore, it is seen that the present invention and the embodiments disclosed herein are well adapted to carry out the objectives and obtain the ends set forth. Certain changes can be made in the subject matter without departing from the spirit and the scope of this invention. It is realized that changes are possible within the scope of this invention and it is further intended that each element or step recited is to be understood as referring to all equivalent elements or steps. The description is intended to cover the invention as broadly as legally possible in whatever form it may be utilized. | A rotary blowout preventer has a first and a second fluid circuit. Each of the fluid circuits are defined into and out of a stationary body and between the stationary body, a rotating body, and two seals. The first fluid circuit is physically independent from the second fluid circuit although they share a seal interface. A fluid is introduced into the first fluid circuit at a pressure responsive to the well bore pressure. A fluid is introduced into the second fluid circuit at a pressure responsive to and lower than the pressure of the fluid in the first circuit. Adjustable orifices are connected to the outlet of the first and second fluid circuits to control such pressures within the circuits. Such pressures affect the wear rates of the seals. The system can therefore control the wear rate of one seal relative to another seal. A thrust bearing is added to share the load placed upon the upper bearings. The thrust bearing is connected between the top end of a packer sleeve and the stationary body. | 8 |
This is a division of application Ser. No. 691,289, filed June 1, 1976 now U.S. Pat. No. 4,071,231.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to the fields of tomography and pneumoencephalography, and more specifically to patient supporting apparatus for making tomograms during pneumoencephalography.
2. Description of the Prior Art
Pneumoencephalography is a medical procedure for determining the size and location of brain tumors. A tumor in the brain normally distorts the shape of the ventricles or cavities in the brain. Accordingly, a picture of the exact shape of the ventricles would indirectly reveal to a great extent the size and location of any major tumor. Unfortunatley the ventricles are normally filled with cerebral fluid, which absorbs x-rays about as well as brain tissue, so that the ventricles cannot ordinarily be x-rayed well even with tomography. Tomography is an x-ray technique whereby the x-ray source and film are moved about during exposure in a fashion so that only one plane through the body or object is clearly seen and other planes are blurred and not distinctly seen. In pneumoencephalography a small amount of air is injected into the spinal column of an erect patient so that is travels up the spinal column and into the ventricles where it displaces some of the cerebral fluid in the ventricles. The difference is sufficient between the x-ray absorption of brain tissue and of air to then make tomographic x-ray exposures showing the shape of the air bubble, which corresponds to the shape of the ventricles bounding the air bubble. Ordinarily a series of many exposures is made during which the patient is positioned in different orientations with respect to gravity so that the air bubble moves around to different ventricles and to different sides of the same ventricles.
Prior art apparatus for carrying out this method includes a patient supporting apparatus that is capable of moving the patient into the many required positions. Once the patient has been properly positioned with respect to gravity and the bubble is theoretically at a desired location, the supporting apparatus and patient are positioned with respect to a tomography machine so that one or more tomograms of the brain can be made with the patient and bubble in that position. Thereafter, the patient is repositioned and the supporting apparatus and patient are again positioned with respect to the tomography machine for more tomograms of the brain. Because the patient's head must be positioned very close to the tomography table and at a fairly precise location, in prior art apparatus, the patient must be moved at least slightly away from the table for repositioning because the table would otherwise interfere with the repositioning. After the patient is repositioned, his head must then again be brought very close to the tomography table and to a fairly precise location. It should be appreciated that at least six, preferably nine, and possibly as many as twelve or more patient positions are required and that each time the head must be accurately positioned with respect to the tomography machine. Prior art supporting apparatus obviously has means for making accurate position adjustment, but the procedure is time consuming and prone to error due to the large number of required accurate positionings. Pneumoencephalography is a very traumatic and painful experience for the patient, so that repetition of the study is very undesirable. Since the entire procedure is also very time consuming, taking several or more hours, any reduction in time required for the procedure is also very desirable.
BRIEF SUMMARY OF THE INVENTION
It is an object of this invention to provide an isocentric means of positioning a patient for peneumoencephalography studies. It is a further object to make the positioning isocenter correspond to the geometric center of the region under study, namely the ventricles of the brain.
Another object is to provide full positioning freedom about the region under study without moving the region of study out of position for taking tomograms thereof.
A further object is to provide patient supporting and positioning apparatus for pneumoencephalography studies which does not require more than one accurate positioning procedure.
Still another object is to provide patient supporting and positioning apparatus for pneumoencephalography which detachably mounts onto a tiltable tomography table.
These and other objects will be apparent from the detailed description of this invention.
A large annular bearing is detachably mountable onto the top surface of a tiltable tomography table in a position such that the axis of the bearing corresponds to the axis of the central ray of the tomography machine. Attached to and supported by this bearing is a chair adapted to support and restrain a patient with his head positioned close to the table on the axis of the central ray. The bearing permits rotation of the chair about the axis of the bearing, thereby permitting rotation of the patient about his head positioned on this axis. The chair is rotatably supported by a shaft having an axis which also passes through the patient's head and furthermore also intersects the axis of the bearing at a point within the patient's head. The shaft axis is inclined from the surface of the table at an angle of preferably about eleven degrees and the patient fits within a space defined by a cone of preferably about twenty-two degrees centered on this axis. The intersection of the rotation axes or positioning isocenter corresponds with the geometric center of tomographic study and the patient may be accurately positioned so that this isocenter corresponds to the geometric center of the ventricles. Thus, the patient may be rotated about the shaft and about the axis of the bearing without moving the geometric center of the ventricles or any other defined center of study with respect to the table.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows one embodiment of the novel patient supporting chair in perspective mounted on a vertically positioned tomography table.
FIG. 2 is a top view of the chair mounted on a tomography table which is a horizontal position.
FIG. 3 is a more detailed side view of the chair mounted on a vertically positioned tomography table.
FIG. 4 is a cut away top sectional view of the chair mounted on a vertically positioned table.
FIG. 5 is a cut away top sectional view of the shin restraint supporting mechanism.
FIG. 6 is a side cross sectional view of the shaft which supports the chair and the main support shaft for the chin, arm and shin restraints.
FIG. 7 is a side cross sectional view of the chin restraint.
FIG. 8 is a cut away top view of the chair supporting mechanism.
FIG. 9 is a cross sectional view of the worm wheel drive for rotating the chair about its supporting shaft.
FIG. 10 is a detailed view of the lever assembly which releases the chair for rotation about the main bearing.
FIG. 11 is a top view of the main bearing.
FIGS. 12 and 13 are top and side view respectively of the assembly for detachably mounting the main bearing to the table.
FIG. 14 is a side cross sectional view of a portion of the main bearing.
FIGS. 15, 16 and 17 are top, front and side cross sectional view of the pin locking assembly for the main bearing.
FIGS. 18 and 19 show side and front views respectively of the patient with respect to the axes of rotation and the cone space within which the patient fits.
FIG. 20 illustrates a child's chair which may be mounted on the chair supporting shaft in place of the larger chair for adults.
FIG. 21 illustrates a chair supporting a patient in a position where all degrees of movement freedom have been exercised.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings generally and more specifically to FIGS. 1, 2 and 21, a patient supporting chair 10 is mounted on a main support shaft 11 which is rotatably supported by tubes 12. Main bearing 13 is detachably mounted to rails 14 in tomographic table 15 and supports tubes 12 in cantilever fashion. Motor 16 at the base of shaft 11 rotates shaft 11 and is controlled with hand control 17 (FIG. 2). A lever 18 releases main bearing 13 for rotation. A parallelogram arrangement of mechanical arms 19 associates the motion of x-ray source 20 to the motion of x-ray film holder 21 for making tomograms. The particular blurring trajectory or geometric pattern traced by the source and holder in this embodiment is variable and may be adjusted by means of gearbox apparatus generally indicated by reference numeral 22. Tomographic table 15 may be tilted from horizontal to vertical with hand control 17 and source 20 and film holder 21 rotate with the table so that the orientation thereof does not change with respect to the table.
Tomography apparatus 15, 19-22 is of a type commerically available and in common use. One example of such a machine is the polytome U3 sold by Philips Medical Systems, Inc., Shelton Connecticut. In this device the blurring trajectory may be linear, circular, elliptical or hypocycloidal, with a free choice of orientation thereof. A detailed understanding of such tomography apparatus is not required for a full understanding of the present invention.
Referring now more particularly to FIGS. 3 and 4, the main bearing 13 supports two tubular members 12, which in turn carry the main shaft which supports the chair 10. The chair 10 includes a padded seat 23 with integral back support 24. Shoulder support 25 wraps around the patient and is secured in the front with one or more velcro closure straps. Shoulder support 25 may be adjusted up and down and a semi-flexible band 26 secures it to the back support 24 by engaging a pin 27 with one of several different holes in the band 26. Bar 28 assures by its proximity to pin 27 that pin 27 will remain engaged with any selected hole in band 26. This arrangement functions like some apparel belt buckles. Strap 29 holds the patient's thighs against seat 23. Strap 30 engages the patient's abdomen and forces his lower back against back support 24. Strap 31 crosses the patient's chest and holds the upper back and shoulders against shoulder support 25. There is another strap 31 crossing the chest from the other shoulder.
Mechanically linked rigidly with the chair seat or the shaft supporting the chair seat is a support arm 32 which carries an auxiliary support shaft 33. Shin restraint 34, forearm restraint 35 and head restraint 36 are all supported by arm 32. Head restraint 36 comprises an integrally molded plastic member 37 that resembles a portion of a football helmet. Member 37 supports four straps 38, 39, 40 and 41 which hold the patient's head in a fixed position relative to member 37. Ordinarily, padding is placed for comfort between the head and member 37 and between the head and straps 38, 39 40 and 41. Member 37 may be molded in many forms so long as it functions to hold the head firmly in a fixed position. Head support 36 also includes a chin support 43 and both member 37 and the chin support 43 are supported by shaft 44 which has ball joints 45 and 46 on either end for adjustment freedom. Shaft 44 furthermore is adjustable in length as will be described in further detail below with reference to FIG. 7.
A tray 47 of sterilizable material is detachably mounted to the rear of seat 23 via thumb screws 48 to hold medical supplies and tools during the spinal surgical procedure. An opening 49 (FIG. 2) in the back support 24 of the chair permits access to the lumbar region of the spine where a puncture is made, cerebrospinal fluid removed and small amounts of air injected.
The height of the chair 10 is adjustable by turning crank 50. In FIG. 3 all body support elements except toe guard 51 are mechanically attached to the chair so that adjustment of the height via crank 50 moves all support elements together. It is alternatively possible, though not preferred, to secure certain support elements directly to shaft 11. FIGS. 1, 2 and 21, for example, show an embodiment where the shin supports 34 are mechanically attached to shaft 11 and do not therefore move up or down with the chair 10. Casters 52 are used to roll the entire patient support apparatus to and from the table in wheel barrow fashion.
FIG. 5 shows in cross section the shin restraint supporting mechanism which clamps onto auxiliary support shaft 33. Hand crank 53 is used to rotate shaft 54 which turns screw 55 to reduce spaces 56, thereby frictionally securing the element 57 to shaft 33 and shaft 58 to element 57. Rods 59 are secured to shaft 58 by pins 60. Shin restraints 34 are attached along rods 59 as shown more clearly in FIG. 8. A simple turn of crank 53 thus secures or releases the shin restraints.
FIG. 6 is a side view of the main support shaft 11. Crank rod 60 drives bevel gears 61 which rotate jack screw 62 and raises or lowers seat 23. Anti-rotation shoes 63 link rotation of the seat 23 to worm wheel 64, which is driven by a motor as is more clearly shown in FIG. 9. Hand crank 65 operates similarly to previously described crank 53 to clamp thereto the shaft which supports the forearm and head restraints.
FIG. 7 is a cross sectional view of shaft 44 which supports the head restraint 36. Shaft 66 is mechanically secured to chair 10 via crank 65 as above described. Lock nut 67 cooperates with thrust bearing 68 to simultaneously lock the positions of ball joints 45 and 46 as well as telescoping shaft 44.
FIG. 8 shows a cut away top view of the chair supporting mechanism. Seat 23 is attached to bracket 69 by four hand screws 70. Bracket 32 supports the shaft 33 which via element 57 and shaft 58 supports shafts 59. Shin restraints 34 are mounted on shafts 59 at any one of several different regions of reduced diameter by spring loaded pins 71. Pins 71 have a region of greater diameter for engagement with the regions of reduced diameter on shaft 59. Crank rod 60 is turned by crank handle 72 to raise or lower the seat 11 as previously described. An additional crank rod 73 and handle 74 serve the same purpose and facilitate hand adjustment of height from the opposite side.
FIG. 9 illustrates the worm wheel drive for the main shaft 11. Motor 16 turns worm wheel 64 which turns the main shaft assembly concentric therewith. Cable 77 controls motor 16 and is carried inside one of the tubes 12 to bearing 13. Lever 18 pulls bowden wire 76 to release the main bearing 13.
FIG. 10 is a more detailed view of the lever assembly connecting lever 18 to bowden wire 76. Cranking handle 18 turns shaft 78 and swings arm 79 which is pinned thereto. Bowden wire 76 is attached to arm 79 so as to be pushed or pulled by arm 79.
FIG. 11 is a top view and FIG. 14 is a cross-sectional view of the main bearing 13. The large open aperture 80 is substantially larger than a patient's head so that the metal of the bearing does not interfere with tomography within the aperture. A first bearing portion 87 is detachably mounted to the table 15 via rails 14. Bearing portion 81 is annular with an inward flange portion 82. A second bearing portion 83 which is also annular is rotatably mounted inside of portion 81 and rides on the flange portion 82 via rollers spaced along the flange portion 82. Portion 83 comprises a top annular element 85 and a bottom annular element 86 attached together with screws 87. Cable 88 contains electrical wires for powering motor 16 and for sensing the condition of a microswitch 89 (FIG. 15). A hollow channel 90 in bearing 13 carries electrical wires from cable 88 to microswitch 89 and to the tube 12 which leads to motor 16. Spaced at about 15 degree intervals around half of the circumference of bearing portion 81 are holes 91, the bearing portions 81 and 83 are locked in a predetermined position. In order to rotate bearing portion 83, the pin 92 must be withdrawn from engagement with all of the holes 91 by actuation of lever 18 (FIG. 9) and bowden wire 76. When bowden wire 76 is withdrawn toward lever 18, microswitch 89 is triggered to cause a visual indication of the pin release. Withdrawl of the bowden wire 76 rotates member 93 about axis 94 to lift pin 92 against spring 95 (FIGS. 15, 16 and 17).
Main bearing 13 may be held to rails 14 in any convenient manner. A preferred method employs a member 96 (FIGS. 12 and 13) which fits into rails 14 from the ends thereof and cannot be pulled out perpendicular to the table. Element 96 has two slots 97 and 98 which receive flange portions 99, 100, 101, 102 attached rigidly to bearing 13. Portions 99, 100, 101, 102 fit directly into slots 97, 98 from the table top and may be lifted away with bearing 13 when lever 103 is in the position shown in FIG. 13. However, when lever 103 is depressed, portions 102 and 103 are forced apart and the inclined sides of portions 96, 100, 101 and 103 contact each other forcing element 96 against the top inside surface of rails 14. A strong frictional attachment is thereby formed between bearing 13 and rails 14 via element 96. Lever 103 has a pivot 104 sufficiently low to assure that it passes center position so that the lever stays depressed until manually raised. Arm 105 is adjustible so that portions 99 and 102 are properly spaced to achieve the above aims. A spring loaded pin 106 fits in hole 107 to accurately locate the locking mechanism with respect to the central ray axis of the tomography apparatus.
Although a thorough understanding of tomography is not required to understand the present invention, an appreciation is required of the location and orientation of the central ray axis and the plane or possible different planes which may be sharply imaged by the tomographic apparatus.
Even when several different geometric patterns may be alternatively selected, each has a geometric center and normally all the geometric centers are in the same position. The axis of the x-ray beam, when it is at this geometric center, may be defined as the axis of the central ray. Alternatively it may be defined as the most central or average of the many orientations that the x-ray beam goes through during a tomography exposure. Whatever the definition, tomography apparatus typically has focal distance adjustments which allow various parallel planes to be sharply imaged. Each such plane has a useful field and each field has a center. A straight line connecting the centers of all the different useful fields is the axis of interest and is herein referred to as the central ray axis or axis of the central ray. In the apparatus illustrated in this embodiment, the central ray axis 108 (FIG. 3) is in a fixed position perpendicular to the table regardless of table tilt, and the parallel planes which may be sharply imaged are all parallel to the table and spaced from the table by distances ranging from zero to 25 cm or about zero to ten inches.
The function of the patient support apparatus herein described is to support the patient and his head so that a defined point within the head remains stationary even though the chair is rotated about the main shaft 11 or about the axis of rotation of bearing 13. It has been determined that at least 99 percent of the adult population may be fitted within the cone region shown in FIGS. 18 and 19, where R is about eight inches and θ is eleven degrees. The preferred chair is adapted to receive the patient within such a space. The distance to the table from the isocenter is then about eight inches which falls within the range of zero to ten inches and still permits slices to be taken up to two inches above the defined isocenter. The isocenter is preferably located at some point between three cm anterior to the middle ear and three cm posterior to the middle ear and in the lateral direction between the mid-orbits. | Chair apparatus specially adapted for detachable mounting on a tiltable tomography table to restrain and support a patient and his head for tomographic exposures during pneumoencephalography. The chair apparatus positions the patient's head close to the tomography table and permits multiaxial rotation of the patient about his head so that a defined isocenter in the patient's brain does not move with respect to the table. Two axes of rotation intersect the geometric center of tomographic study. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Provisional application No. 61/842,376, filed on Jul. 2, 2013
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
[0004] Not Applicable
FIELD OF THE INVENTION
[0005] The present invention relates to a pin protector for protecting pins of light bulbs from damage during transportation. In particular, the pin protector made of plastic material includes a top having at least one recessed hole for inserting pins of light bulbs into, a bottom and a surrounding side structure. The pins of light bulbs will be inserted into holes of pin protector and protected from damage by external force during transportation.
BACKGROUND OF THE INVENTION
[0006] Light bulbs, such as LED/fluorescent tubes and LED/CFL bulbs, comprise a plurality of pins on a first end and/or a second end. The pins constitute as mechanical parts to install the light bulbs and electrical parts to conduct electricity. A damaged pin might lead to potential safety issue to end user, or malfunction of the whole light bulb. However these pins are easy to be damaged during transportation when they are exposed to external force or not well protected. To overcome the said issue, the inventor proposes a solution as described below.
SUMMARY OF THE INVENTION
[0007] The main objective of the invention is to provide a pin protector which is simple in structure, cost effective and easy to use. The pin protector has a top having at least one recessed hole for inserting pins of light bulbs into, a bottom and a surrounding side structure. The pin protector is made of plastic material and resistant to external force. Since the pin protector is made of plastic material, the unit cost of pin protector is a very small fraction of light bulb cost.
[0008] The pins of light bulbs can be easily inserted into holes of the pin protector by pushing with just one finger and removed off pins by pulling with just two fingers.
[0009] These and other aspects of the invention are described in the detailed description of the invention and claimed in the claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention will be further understood from the following description with reference to the accompanying drawings, in which:
[0011] FIG. 1 illustrates a pin protector with two holes;
[0012] FIG. 2 is the top view of the pin protector;
[0013] FIG. 3 is bottom view of the pin protector,
[0014] FIGS. 4 a and 4 b are cross sectional views of the pin protector,
[0015] FIG. 5 shows some examples of tops and corresponding bottoms of the pin protector;
[0016] FIG. 6 is an embodiment showing a pin protector with two holes attached to a linear LED tube.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which a preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein. Rather, this embodiment is provided so that this application will be thorough and complete, and will fully convey the true scope of the invention to those skilled in the art.
[0018] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present inventive subject matter. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
[0019] It will be understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items and may be abbreviated as “/”.
[0020] It will be further understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first region/layer could be termed a second region/layer, and, similarly, a second region/layer could be termed a first region/layer without departing from the teachings of the disclosure.
[0021] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this inventive subject matter belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and/or the present application, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0022] The present invention relates to a pin protector for protecting pins of light bulbs. The light bulbs may be incandescent bulbs, compact fluorescent light (CFL) bulbs, linear fluorescent lamps, LED bulbs or any other bulbs now known or later developed. The light bulbs have at least one base which might further have one pin, two pins, four pins.
[0023] As shown in FIGS. 1-3 , 4 a and 4 b , the pin protector 1 is made of plastic material and comprises a top 10 , a bottom 13 and a surrounding side structure 12 . At least one hole 11 are recessed into top 10 . Top 10 and bottom 13 are provided in the same shape and dimension. Surrounding side structure 12 extends from top 10 to bottom 13 .
[0024] FIG. 5 shows various shapes of top 10 and bottom 13 including rectangle top 10 and rectangle bottom 13 , square top 15 and square bottom 16 , circular top 17 and circular bottom 18 , cross top 19 and cross bottom 20 , hexagonal top 21 and hexagonal bottom 22 , and triangle top 23 and triangle bottom 24 .
[0025] FIG. 6 shows a preferred embodiment, pin protectors 1 are used to protect a linear LED tube 2 . A linear LED tube 2 comprises a linear structure 25 , and two end caps 26 which further have a plastic part 27 and two pins 28 . The linear structure 25 has a first end and a second end. Each end is arranged with an end cap 26 . The linear structure 25 extends between two end caps 26 . In this embodiment, each end cap 26 is attached into holes 11 of a pin protector 1 . | The invention discloses a pin protector for protecting pins of light bulbs from damage during transportation. The protector is made of plastic and includes a top having at least one recessed hole for inserting pins of light bulbs into, a bottom and a surrounding side structure. This particular feature mechanically protects the pins when there is an external force. | 5 |
This is a division of application Ser. No. 167,323, filed July 10, 1980.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains, in its most general sense, to a process for continuously coating elongated and continuous bodies with a suitable protective coating. In its most immediate sense, this invention pertains to a process for coating wire such as that which is used in winding coils, in armatures and the like, and to apparatus with which the process can be carried out.
2. Description of the Prior Art
Wires, particularly wires which are utilized in coils and in windings in rotating machinery, are conventionally insulated so that the coils and windings formed thereby will not short out between adjacent wire sections. Such insulated wires are conventionally referred to as lacquered wires.
In the prior art, lacquered wires are produced by dissolving suitable insulation into a light hydrocarbon binder such as cresol which serves as a solvent, in order to provide a lacquer which is of a suitable viscosity for coating the wire. After the wire has been coated with the lacquer so produced, it is necessary to evaporate the solvent by subjecting the coated wire to elevated temperatures, and it is further necessary to harden the lacquer after the solvent has been evaporated therefrom in order to impart the necessary mechanical characteristics and electrical insulation characteristics which are required for wires of this type.
When this method is utilized, toxic or poisonous gases are emitted during the evaporation and hardening stages of the wire, making the process environmentally polluting. Moreover, the evaporation process is, in and of itself, an energy-intensive one, independently of the energy consumed during the subsequent hardening process.
In Federal Republic of Germany Offenlegungsschrift No. 27 44 721, a pulverized coating is disclosed which can be used to coat many types of articles in order to provide a mechanically stable corrosion shield. This reference also indicates that a pulverized material may be applied to such an article by means of an electrostatic process. Such processes involve the utilization of a coating chamber in which the pulverized material is given a negative charge while the object to be coated is given a positive charge. As a result of the potential difference between the pulverized material and the object to be coated, the pulverized material is set into motion and attracted onto the surface of the article to be coated, forming a coating which may later be sintered and fused onto the article to form a protective coating which is mechanically stable. In such electrostatic coating processes the thickness of the coating is a function of the duration in which the article remains in the coating chamber.
Existing electrostatic coating machines which utilize this principle to coat articles with coatings such as that disclosed in the above-mentioned reference are unsuitable for use in connection with coating elongated and continuous elements such as wire. Even if the structure of such devices were to be modified in order to accommodate wire (a modification not as yet known), such devices would be unsuitable because tolerances in insulation thickness of lacquered wire must as a practical matter be held at least within±10 micrometers, and preferably better. This type of close-tolerance manufacture is necessary in order to insure that the insulation coating on the wire has a sufficiently high resistance to high voltage so that apparatus in which the wire is installed will not be subject to shorting and will not exceed the dimensions which practice dictates to be necessary.
Finally, it would be desirable to utilize a continuous sintering and hardening process in order to allow a continuous manufacturing process to take place over days and weeks. Such processes depend upon the uniformity of the particle size of the pulverized material which is to be sintered and hardened.
Thus, it would be desirable to provide a method for manufacturing lacquered wire which would not pollute the atmosphere with toxic or poisonous fumes, which would not be as energy-intensive as prior art methods, which would produce lacquered wire with an adequately uniform insulation thickness, and which would utilize a continuous sintering and hardening process.
SUMMARY OF THE INVENTION
These objects, along with other which will appear hereinafter, are achieved in this invention by an apparatus which utilizes a speed-regulated transport system used to pass were to be coated through three stages: a stage of electrostatic coating, a stage of sintering and hardening, and a stage of cooling. The apparatus provides means for continuously monitoring the thickness of the coated wire, means for supplying an insulator in pulverized form, means for sintering and hardening of the coated wire and means for increasing or decreasing supply of insulator in pulverized form in response to the measured value of the insulation thickness so as to maintain a desired insulation thickness within a predetermined tolerance, while the wire is proceeding at a constant even speed chosen and regulated in accordance with the time required for hardening the insulation-coat.
Inasmuch as the insulation utilized is in pulverized form and therefore is not dissolved in any solvent no toxic or poisonous fumes are given off as the solvent evaporates during manufacture. Inasmuch as wire speed through the apparatus can be varied directly in accordance with thickness the apparatus can be used for insulate wire, which is comparatively large and which has a cross-sectional area of more than 1.5 square millimeters. By use of this apparatus insulation thickness can be held to a maximum tolerance of 10 micrometers.
In the process disclosed herein, the powdered insulation is continuously fed into an electrostatic coating machine at such a rate that powdered insulator adhering to the wire in an electrostatic coating process is continuously replenished, avoiding a situation in which the amount of pulverized insulator inside the electrostatic coating machine gradually diminishes. In the event that the supply of pulverized insulator were not held constant within the electrostatic coating machine, a selection process would take place in which the lightest and smallest particles of insulator would first be attracted to the wire to be coated. In this situation, the size of particles attracted to the wire would not be uniform over the entire wire surface, since the lightest particles would be depleted first and as time elapsed, the average size of particles attracted to the wire would increase. This undesirable selection phenomenon would result in a less-uniform product after sintering and hardening.
However, by keeping the quantity of pulverized substance in the electrostatic coating machine constant, and by replenishing this material as it is used, this selection phenomenon is avoided and a uniform insulating coating results.
If desired, both the potential difference between the pulverized insulator and the distance along the wire which is actually exposed thereto can be varied during the process in order to even more accurately control insulation uniformity.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
In the single FIGURE, the method disclosed herein and the apparatus for implementing the method are shown in a single schematic elevational view.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A storage drum 2 mounted to rotate about an axis 2A so that storage drum 2 can rotate carries uninsulated wire which is made to pass along a wire path 18. The wire path, shown in the FIGURE as a broken line having arrows showing the direction of wire travel, is first made to pass over a speed-regulated roller 15 into the intake end of electrostatic coating machine 3, in which an insulator is electrostatically adhered to the wire as is set forth in more detail below. After having been so coated, the wire passes out of the outlet end of the electrostatic coating machine 3 into the intake end of the sintering and hardening oven 4 into a sintering section 13 where the insulation which has electrostatically adhered to the wire is sintered and subsequently hardened in hardening section 14. After hardening in hardening section 14, the wire passes out the outlet end of oven 4, and is directed into the intake end of a cooler 5 where the insulated wire now bearing a sintered and hardened coating of insulation is cooled down. After cooling, the wire is wound up on a rotatable takeup spool 1 in its finished state, ready for subsequent use.
After the wire passes out of the outlet end of cooler 5 its thickness is measured by a thickness sensor 7. Inasmuch as the original diameter of the wire prior to coating is known, thickness sensor 7 serves the purpose of determining the thickness of the sintered and hardened coating of insulation which is applied to the wire with a high degree of accuracy. Thickness sensor 7, as will be seen hereinafter, is used to regulate the rate of supply of an insulator in pulverized form into the electrostatic coating machine 3 so as to insure a properly uniform insulation thickness all along the wire.
Referring now the operation of electrostatic coating machine 3 in more detail, it can be seen that electrostatic coating machine 3 is attached to reservoir 8 through regulating valve 9. Reservoir 8 contains an insulator in pulverized form which is introduced into electrostatic coating machine 3 in dependence upon setting of valve 9, which setting can be varied in accordance with wire thickness as measured by thickness sensor 7, which thickness sensor 7 is connected to valve 9 via control line 10. Suitable insulators for use in reservoir 8 include thermosetting plastics, such as those which use a polyurethane-polyamide base.
Whenever insulator is introduced into reservoir 8, it is finely pulverized so as to be able to flow smoothly into electrostatic coating machine 3 and to coat the wire in a uniform fashion. Electrostatic coating machine 3 utilizes an AC field to establish a potential difference between the wire and the pulverized insulator. As a result of this potential difference, the pulverized insulator is electrostatically attracted to the wire and adheres thereto.
Still remaining with the operation of electrostatic coating machine 3, it can be seen that the wire path passes through a first shield 11 located within the intake end of electrostatic coating machine 3. As shown in the FIGURE, first shield 11 takes the shape of a hollow cylinder, and is slidable back and forth parallel to wire path 18 within bearing 16. In a similar fashion, second shield 12, also shaped in the form of a hollow cylinder, is located within the outlet end of electrostatic coating machine 3 and can be slid back and forth parallel to wire path 18 within bearing 17. First shield 11 and second shield 12 serve to shield the surface of wire passing through electrostatic coating machine 3. The AC field which is used to attract the insulator introduced into electrostatic coating machine 3 from reservoir 8 only causes insulator to be attracted to an exposed section of the wire. This exposed section exists between the two innermost ends of shields 11 and 12. In the event that the exposed section of the wire is to be increased, which will cause more insulator to be electrostatically attracted to the wire during a given unit of time, shields 11 and 12 can be moved away from each other so as to expose more of the wire surface to the insulator. On the other hand, if the exposed section of the wire is to be reduced in order to reduce the amount of insulator electrostatically adhered thereto per unit time, shields 11 and 12 can be moved towards each other, thereby reducing the exposed surface of the wire to which the insulator is adhered. Finally, the AC field which is used to induce a potential difference between the wire and the insulator can be varied.
It will be appreciated by those skilled in the art that the thickness of the layer which is electrostatically adhered to the wire will depend upon a collection of factors, which factors include the period during which the given section of wire is exposed to the insulator and the magnitude of the potential difference between the insulator and the wire, as well as the quantity of the pulverized insulator within the coating machine. It will be appreciated that the time required for sintering and hardening this insulating layer can be varied by varying wire speed along wire path 18, while the thickness of this insulating layer can be varied by varying distance between shields 11 and 12, or by varying the rate of such supply of pulverized insulator and such distance conjointly also with variation of the potential difference between the wire and the insulator. In one embodiment of the process disclosed herein, the supply of the pulverized insulator alone is varied in direct dependence upon thickness of the wire as measured by thickness sensor 7, whereas in other embodiments of this process any of the factors of wire speed, distance between shields 11 and 12, and potential difference between the wire and the insulator can be simultaneously varied in accordance with wire thickness as measured by thickness sensor 7, the speed of the wire being regulated in accordance with the time required for hardening of the insulating coat such applied on the wire and the mechanical tension thereof, both to be evenly constant at a chosen value for each production.
As mentioned above, control line 10 connects regulating valve 9 to thickness sensor 7. Regulating valve 9 continuously adjusts flow of insulator from reservoir 8 to electrostatic coating machine 3. By so doing, the quantity of insulator inside electrostatic coating machine 3 is held constantly in accordance with the thickness of the insulating coat to be applied. By so doing, the smaller and lighter particles of insulator are not immediately attracted to the wire, leaving larger and heavier particles to be attracted subsequently. As has been set forth above, such a selection phenomenon would deleteriously affect uniformity of insulation thickness, since without such continuous replenishment of the quantity of insulator within the electrostatic coating machine, particle size of insulator attracted to the wire would gradually increase as the smallest and lightest particles were depleted, leaving only heavier and larger ones available for subsequent electrostatic attraction to the wire.
After the wire has been coated with insulator in electrostatic coating machine 3, the wire passes into sintering section 13 of sintering and hardening oven 4. In sintering section 13, the insulator is sintered and adhered to the wire. Sintering section 13 may in fact be a plurality of heating stages which establish an increasing temperature profile. Thus, for example, a subsection of sintering section 13 may initially raise the temperature of the coated wire from room temperature to approximately 200° C. so as to cause the insulation to melt in a uniform fashion over the surface of the wire. Subsequently, another subsection of sintering section 13 may for example raise the temperature of the wire and insulation to approximately 250° C. to conclude the sintering process.
After the sintering process has been concluded, the wire is passed through hardening section 14, which may for example be two subsections placed one after the other in a fashion similar to sintering section 13. For example, hardening may initially take place in a first subsection in which the wire with its sintered coating is heated to perhaps 250° to 300° C. Subsequently, another stage can heat the wire with its sintered and partially hardened coating of insulation to approximately 350° C., to conclude the hardening process.
Sintering and hardening oven 4 may take a plurality of forms. It is possible that sintering and hardening oven 4 may be a multi-stage muffled furnace, and it is possible that the hardening section 14 of sintering and hardening oven 4 may harden the insulation by causing ultraviolet radiation to be directed upon it.
Sintering section 13 and hardening section 14 may have any number of subsections or stages, and may use any type of incident radiation such as infrared radiation and ultraviolet radiation as long as an appropriate temperature profile is established which will properly sinter and harden the particular insulator which is used in reservoir 8 within a period of time, depending upon the length of the respective hardening section 14 and the speed at which the wire is passed therethrough. After sintering and hardening, the wire is passed through an elongated cooler 5, in which the wire can once again be cooled down to room temperature. Cooler 5 may be refrigerated in some way or may merely be an elongated hollow housing in which air passes around the wire and cools it down. In any event, after cooling in cooler 5, wire thickness is measured by a thickness sensor 7. After passing by thickness sensor 7, the wire can be rolled up on takeup spool 1 ready for subsequent use.
Takeup spool 1 cooperates with a sliding clutch, which sliding clutch cooperates with speed-regulated roller 15 in a manner not shown to keep wire tension constant at an appropriate value. Moreover, thickness sensor 7 cooperates with roller 15 via appropriate devices (not shown) to vary wire speed in accordance with wire thickness as measured at the outlet end of cooler 5. In one embodiment of the process disclosed herein, distance between shields 11 and 12 is preset, as is the potential difference between the wire and the insulator, and only insulation-powder supply is varied, in direct dependence upon wire thickness as measured at thickness sensor 7. In another embodiment of the process disclosed herein, any of the factors of wire speed, distance between shields 11 and 12, and potential difference may be varied in order to achieve an appropriately uniform insulation thickness.
In an alternative embodiment, thickness sensor 7 is not disposed at the outlet end of cooler 5 but is rather disposed between the outlet end of sintering and hardening oven 4 and the intake end of cooler 5. It is only necessary to measure thickness of the coated wire after the sintering and hardening processes have been completed.
The apparatus disclosed herein can be arranged in a compact fashion. As shown in the FIGURE, the drum 2, electrostatic coating machine 3, and sintering and hardening oven 4 are all attached to a base plate 6, which supports these elements on appropriate stands.
The process disclosed herein can produce satisfactory lacquered wires even with large cross-sectional areas. By way of a first example, a wire with a cross-sectional area of 10 square millimeters can be coated with insulation to a thickness of 120 micrometers within a tolerance of ±10 micrometers. In order to accomplish this result, the sintering and hardening oven 4 is 4 meters long, wire speed is 5 meters per minute, the exposed section of wire inside the electrostatic coating machine 3 is 400 millimeters, and the potential difference between the wire and the insulator is set at 20 kilovolts. By way of a second example, a wire with a cross-sectional area of 50 square millimeters can be likewise coated with insulation to a thickness of 120 micrometers, when the sintering and hardening oven 4 is 6 meters long, when the wire speed is set at 2 meters per minute, when the exposed section of the wire is 500 millimeters long, and when the potential difference is increased to 25 kilovolts.
It can now be seen that because no solvent is used in connection with the insulation in reservior 8, no toxic or poisonous fumes are emitted during the process disclosed herein, resulting in a non-polluting insulation process. Moreover, the process is entirely continuous since it is possible to accurately coat wire of even large cross-sectional area with a desired thickness of insulation within a predetermined tolerance by varying the quantity of the insulator supplied in pulverized form into the coating machine, the exposed wire section therein and/or potential difference conjointly with each other. In this connection, it is noteworthy that in order to achieve these results, the insulation within the electrostatic coating machine 3 must remain uninfluenced by any disturbing factors, such as gas flows and the like.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of methods and arrangements differing from the types described above.
While the invention has been illustrated and described as embodied in a method and arrangement, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. | A device for coating wire with a pulverized insulating material wherein wire is coated with the insulator in an electrostatic coating machine which establishes a potential difference between the wire and the insulation and thereby causes the insulation to adhere to the wire electrostatically, without the use of solvents. After such coating, the coated wire is sintered and hardened in a sintering and hardening oven in order to form a lacquered wire with a uniform insulation thickness. Insulation thickness can be maintained at a desired value by the control device for adjusting the length of wire being exposed to the insulator in pulverized form within the electrostatic coating machine. The supply of insulator used in pulverized form is continuously fed from a reservoir into the electrostatic coating machine so as to prevent smaller and lighter particles from being first attracted to the wire, and thereby depleting such particles excessively while leaving only larger and heavier particles available for coating. The final thickness of the insulation is constantly measured by a thickness sensor and kept within a predetermined tolerance by varying the rate of feed of insulator supply to the coating machine by a valve connected to the sensor, directly as a function of insulation thickness. | 1 |
REFERENCE TO RELATED APPLICATIONS
[0001] This application claims an invention which was disclosed in Provisional Application No. 60/495,226, filed Aug. 14, 2003, entitled “AIR FLOW MONITORING AND CONTROL SYSTEM WITH REDUCED FALSE ALARMS”. The benefit under 35 USC §119(e) of the U.S. provisional application is hereby claimed, and the aforementioned application is hereby incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention pertains to the field of monitoring and control of air flow handling devices such as laboratory fume hoods. More particularly, the invention pertains to methods of avoiding false alarms in air flow monitoring systems for air handling systems.
[0004] 2. Description of Related Art
[0005] Laboratory fume hoods have long been used to extract fumes from the vicinity of laboratory workers. Typically, fume hoods provide an enclosure around and above the experimental area or laboratory table, from which an exhaust fan draws air. Room air flows into the hood from vents or an open front to replace the air drawn out by the hood The extracted air is exhausted through appropriate ductwork to the atmosphere in a safe area, typically the roof of the laboratory building. Makeup air flows into the laboratory to replace the room air exhausted by the hoods.
[0006] Because of the need to maintain airflow through the hoods for safety reasons, it is important to monitor the hoods and make sure that sufficient air is flowing whenever the laboratory is in use. Failure of a fan motor or plugging of air filters, inlets or outlets, could lead to a dangerous diminution in air flow. Therefore, fume hood airflow alarms are provided for this purpose. These alarms monitor the air flow in the hood or the ductwork leading to or from the hood, whether directly or by monitoring pressure differentials, and warn personnel when the flow drops below a predetermined set point.
[0007] Moss, U.S. Pat. No. 4,934,256, “Fume Hood Ventilation Control System”, shows a fume hood equipped with such an airflow monitoring system. U.S. Pat. Nos. 5,439,414 and 5,562,537, assigned to Landis & Gyr Powers, Inc., of Buffalo, N.Y., for “Networked Fume Hood Monitoring System” are examples of networked systems for monitoring a plurality of fume hoods in a facility.
[0008] Overall ventilation for laboratory buildings is usually provided by one or more air handling units (otherwise known as Heating, Ventilation and Air Conditioning or HVAC) which draw in outside air, heat or cool it as needed, and distribute the air to the various areas in the building. Air vents and, if needed, exhaust fans, provide an exit route for the conditioned air.
[0009] In recent years, concerns for energy conservation have led to buildings being made ever more air-tight and energy efficient. This has resulted in a number of problems in laboratory or factory buildings and other similar facilities in which there are a large number of devices such as lab hoods, paint booths, assembly line process equipment using chemicals, stove hoods, etc., extracting conditioned air from the building. When these devices are on, a significant amount of air is pulled from the interior of the building and exhausted to atmosphere. With the building being made as air-tight as possible, it is no longer feasible to depend on leaks around and through windows and doors to replace the extracted air flow. Outside air must be drawn in through the building's air handling equipment to make up for the air leaving through the hoods. Therefore, it is important that the air handling equipment be running when the hoods are on.
[0010] It has become common in recent years for all of the HVAC and other machinery in a facility to be controlled and monitored centrally, with a facility network bus running around the building providing communications for data and commands for all of the equipment. Application Specific Controllers (ASCs) provide interfacing between one or more pieces of equipment and the bus, and a Network Control Module (NCM) connected to the bus monitors and controls the equipment through the ASCs. The NCM may be a stand-alone system or might communicate with one or more conventional microcomputers to provide data monitoring, control and alarm functions using custom or vendor-supplied software, such as the “Metasys” software from Johnson Controls, of Milwaukee, Wis. Johnson Controls also manufactures ASCs and NCMs which are useful with the present invention.
[0011] If the hoods are left on when there is no laboratory activity, a great deal of energy is wasted drawing in outside air through the air handlers, conditioning it, and blowing it out through the roof through the hoods. It would seem logical, then, to shut off hoods and other exhaust devices when there is no longer any need for them. This may be done by manual controls on the hoods, but laboratory users can forget to shut down equipment when they leave. Simple time clocks can provide a shut-off function at night, as well.
[0012] However, if the building is energy efficient, it is not advisable to simply shut down all of the exhaust equipment, as it is important to keep at least a minimal air flow through the facility to maintain fresh air and keep the temperature within limits. Better than just shutting off the hoods, then, is to reduce the air flow through the devices through variable speed drives on the exhaust fans. Thus, when the laboratory shuts down at night, the hood fans can be automatically slowed down to 25%-50% of normal speed.
[0013] A problem arises when this is done. Even though the hoods are not shut off completely, the air flow monitors in the fume hoods will detect the reduction in air flow, and at some point will set off a low air flow alarm. The alarms can be set to a low enough flow that the minimum flow should not set them off, but it is not practical to set this limit too low, or the alarm would not perform its function during the day when it is needed to perform its safety function. Small natural variations in flow can thus cause annoying false alarms as the hood monitors incorrectly interpret a brief drop or rise in hood flow at night as a failure in ventilation. Many facilities have dealt with this by either disconnecting the alarms, to the detriment of facility safety, or keeping the hoods running wastefully 24 hours a day, requiring increased costs of running the HVAC when it is not needed.
SUMMARY OF THE INVENTION
[0014] The invention presents a system for monitoring and controlling air flow in a facility which reduces the number of false alarms due to incorrect sensing of reduced air flow in exhaust devices.
[0015] In the simplest embodiment of the system, an alarm sensor monitors air flow in a fume hood or the like, set to provide a warning if air flow drops below a predetermined amount. A local controller monitors the alarm, and disables it when the hood is set to reduced air flow, whether by a local timer or by command of a central control system. Optionally, the controller itself can operate a variable speed drive to reduce air flow on a timed basis, and the controller can communicate with facility management through a dialer or the Internet, or can interface with a central control for the facility through a facility bus.
[0016] In a preferred embodiment, the system is implemented on a facility-wide basis. Alarms on a plurality of fume hoods or similar devices communicate with an ASC, which is, in turn connected to a facility network bus. At least one air handler is also connected to the bus, providing signals for its status and accepting commands for its operation. The air handler provides control for variable speed drives on the fume hoods, so that when the air handler is set to a night-time setback condition the fans in the hoods are slowed down. When this happens, the ASC disables the alarms in the hoods, so that the reduced air flow does not result in false air flow alarm conditions. Manual overrides on the hoods may be provided to turn the air handler back on, which would in turn set the fume hoods back to full operation and re-enable the alarms.
BRIEF DESCRIPTION OF THE DRAWING
[0017] FIG. 1 shows a block diagram of the system of the invention
[0018] FIG. 2 shows a detail block diagram of a fume hood alarm and monitor
[0019] FIG. 3 shows a block diagram of a simple embodiment of the invention, implemented for a single fume hood.
DETAILED DESCRIPTION OF THE INVENTION
[0020] FIG. 1 shows a block diagram of the invention, as it would be implemented in a laboratory building ( 20 ) having a number of fume hoods ( 1 ). It will be understood that the invention may be used in other applications than fume hoods, wherever there are apparatus which exhaust air from a building, such as spray booths, assembly line ventilators for chemical baths, range or industrial cooking hoods, etc. Also, although the example of FIG. 1 is shown with a single air handler with three associated fume hoods and an exhaust fan, the invention may also be used with any mixture of air handlers, exhaust devices, building zones, etc.
[0021] Referring to FIG. 1 , the dashed line represents a laboratory building ( 20 ) or possibly an air handling zone within a larger facility. Outside air ( 12 ) is drawn into air handler ( 9 ), heated or cooled as required (and possibly filtered, humidified or de-humidified depending on individual building needs), and conditioned air ( 13 ) is sent through the normal building (or zone) air ducts.
[0022] The air handler ( 9 ) is connected to a facility bus ( 15 ), which is a communications line running throughout the facility for communications and control of the various building functions. The air handler ( 9 ) sends information about its operation ( 17 ) to the bus, and receives operational commands ( 16 ) from the bus ( 15 ). In particular, the air handler will report its fan status ( 18 )—that is, whether or not the handler is drawing in outside air ( 12 ). Manual controls ( 10 ) may also be provided to allow local control of the air handler ( 9 ).
[0023] One or more exhaust fans ( 7 ) may be provided to exhaust building air ( 19 ) to the outside. A fan controller ( 8 ) allows the exhaust fan to be started or stopped, or its speed regulated, as might be required.
[0024] Within the laboratories, each experimental position ( 11 ) has a fume hood ( 1 ) with an exhaust fan ( 2 ) which draws air from the hood and exhausts it through ducts to stacks ( 21 ) on the roof of the building (or some other safe place remote from air intakes and casual traffic). A variable speed drive (VSD) ( 5 ) on each fan allows the speed of the fans to be adjusted from the full speed required by normal daytime operation to a lesser speed (25%-50%) during night setback or if the hood is not required. A manual keypad ( 6 ) on each VSD allows manual control of fan speed, and the setback speed may be set by the keypad as well. Alternatively, one or more of the VSD's ( 5 ) could be replaced by an on/off control in which the fans are completely shut off during setback periods.
[0025] Each of the VSD's ( 5 ) and, optionally, the exhaust fan controller ( 8 ) are connected to the air handler by a setback line ( 27 ). A signal on the setback line ( 27 ) causes the fans ( 2 ) and ( 7 ) to revert to their lower nighttime speeds, reducing the air flow out of the building. The setback line ( 27 ) might be as simple as a contact closure indicating “reduce speed” (or, alternatively, “increase speed”, if the setback line were used in reverse to indicate normal operation), or might actually set a specific setback amount, as the system design requires. In any event, it is the air handler ( 9 ) which sets back the exhaust devices ( 2 ) and ( 7 ) through line ( 27 ).
[0026] Under normal operation, then, the system might work on a daily schedule as follows:
TABLE 1 0700-1700 1700-0700 Air Handler ON OFF Fume Hoods ON-Full Speed 25%-50% (60 Hz) (15 Hz-30 Hz) Exhaust Fan ON OFF
[0027] If someone is working in a laboratory at night, they should be able to override this reduction, however, and the air handlers would need to increase their output to compensate for the increased air flow. Override switches ( 14 ) on each lab position ( 11 ) signal the air handler ( 9 ) through line ( 31 ) to switch on. This, in turn, causes the air handler ( 9 ) to turn off setback signal ( 27 ) (or send a “cancel setback” command), which switches the fume hood fans ( 2 ), and optionally the exhaust fan ( 7 ), back to full speed “ON” operation.
[0028] An airflow monitor and alarm unit ( 3 ) is connected to each of the fume hoods ( 1 ), as can be seen in detail in the block diagram of FIG. 2 . A pneumatic tube ( 43 ) leads into the exhaust duct ( 41 ) from the hood. Air flow ( 51 ) in the duct ( 41 ) induces a partial vacuum in line ( 43 ) by the venturi effect, and this is detected by pressure sensor ( 44 ). The sensed pressure is provided to a comparator ( 48 ), which compares the pressure to a desired set point. If the pressure drops below the set point, the comparator outputs a “low pressure” signal ( 29 ), and activates alarm ( 50 ) by turning line ( 49 ) on. An alarm disable switch or relay ( 46 ) interrupts lines ( 29 ) and ( 49 ), silencing the alarm ( 50 ) if an “alarm disable” signal ( 28 ) is present. In the past, this “alarm disable” line was not commonly used, or would simply be connected to a local switch for disabling the alarm entirely.
[0029] The airflow monitor and alarm unit ( 3 ) may be custom built for the purpose, or could be a commercially available unit such as the “Safe Aire® 54L0335” manufactured by Fisher Hamilton LLC, of Two Rivers, Wis.
[0030] Optionally, a “pitot tube” ( 40 ) may be placed in the duct ( 41 ) which produces a positive pressure in line ( 42 ) from a “ram air” effect. This pressure is detected by detector ( 4 ) which sends a simple binary (yes/no) signal ( 30 ) to indicate that there is, or is not, air flow ( 51 ) in the duct ( 41 ). Alternatively, one of the commercially available vane switches could be used for the same purpose.
[0031] The “low pressure” signal ( 29 ) (and optional “air flow” signal ( 30 )) are routed to an Application Specific Controller (ASC) ( 16 ) which is assigned to the particular laboratory, building zone or other area covered by the air handler ( 9 ) and hoods ( 1 ). According to the teachings of the invention, an output from the ASC ( 16 ) is connected to the “alarm disable” lines ( 28 ). The ASC ( 16 ) is connected to the facility bus ( 15 ) by a data line ( 32 ). The ASC might be any of the commercially available units, such as the model DX9100 manufactured by Johnson Controls, Milwaukee, Wis., or could be custom built.
[0032] A Network Control Module ( 22 ), usually at a central location in the facility ( 20 ), is also connected to the facility bus ( 15 ) by a data line. The NCM ( 22 ) performs the functions involved in controlling and monitoring the facility, which might include not only the HVAC functions but also various other alarms and sensors, as desired. The NCM might be any of the commercially available units, such as the Johnson Controls model NCM350, or could be custom built. Control software such as “Metasys” from Johnson Controls, allows programmability of the NCM.
[0033] A microcomputer ( 23 ) is usually provided for programming and monitoring the NCM ( 22 ), and may be connected to a telephone dialer or modem ( 24 ) so that any alarms may be relayed to one or more telephones ( 26 ) or pagers ( 25 ) over the normal telephone lines ( 34 ). The NCM and microcomputer can be programmed to provides detailed reports in order to provide archived history data, alarm data and trend data.
[0034] In normal operation, then, as noted in FIG. 1 , above, the air handler ( 9 ) would be switched on and off according to a time schedule. This switching could be done by the NCM ( 22 ) sending commands through its data link ( 33 ) to the facility bus ( 15 ), and then to the air handler ( 9 ) through line ( 16 ). Alternatively, a time program in the air handler ( 9 ) itself could perform this function.
[0035] When the air handler ( 9 ) is in normal daytime mode, the air handler ( 9 ) “setback” signal ( 27 ) is “off”, and the fume hood fans ( 2 ) and exhaust fans ( 7 ) are thus fully on. The full air flow ( 51 ) in the ducts ( 41 ), detected by sensor ( 44 ) is more than the set point in the comparator ( 48 ), and the low pressure line ( 29 ) is “off”. The air flow sensor ( 4 ) detects the air flow, and sends a confirming “air flow on” signal ( 30 ) to the ASC ( 16 ). Also, the air handler ( 9 ) sends a “fan on” signal ( 18 ) to the ASC. These signals ( 18 ), ( 29 ) and ( 30 ) allow the ASC ( 16 ) to confirm that the system is operating properly, and if any of them are abnormal, allows the ASC to raise an alarm condition through the NCM ( 22 ).
[0036] At the desired “night setback” time (1700/5PM in Table 1), the air handler ( 9 ) is switched “off”, and the handler asserts “setback” line ( 27 ). The exhaust fan controller ( 8 ) shuts off the exhaust fan ( 7 ), and the VSD's ( 5 ) set the fume hood fans ( 2 ) to their preset “setback” speed.
[0037] In the prior art, this is the point at which trouble might arise. As the VSD's ( 5 ) cut the fume hood fans ( 2 ) back to 25%-50% of normal speed, the air flow in the ducts ( 41 ) is reduced. Depending on the set point chosen in comparator ( 48 ), this might immediately cause a “low pressure” condition, or it might be just sufficient to stay above the limit set. If there is any reduction in air flow, though, whether through a partially clogged filter, or a temporary disruption in airflow, the “low pressure” condition will be detected, and comparator ( 48 ) would set off alarm ( 50 ) and send a “low pressure” condition ( 29 ) to the ASC ( 16 ). The ASC ( 16 ) would relay the alarm to the NCM ( 22 ), which would call for help or set off its own false alarms.
[0038] According to the teachings of the invention, however, these false alarms are avoided. The ASC ( 16 ) detects the “fan off” ( 18 ) signal from the air handler ( 9 ), and knows that it is now in “night setback” mode. Therefore, it asserts the “alarm disable” line ( 28 ), which prevents the alarms ( 50 ) from sounding, so long as the system is in setback mode.
[0039] Once the air handler ( 9 ) returns to normal operation, whether through the normal timed schedule or because of an override switch ( 14 ), it turns off the setback ( 27 ), returning the fans ( 2 ) to full operation, and sends “fan on” signal ( 18 ) to the ASC ( 16 ), which ceases to assert “alarm disabled” ( 28 ). The alarm and monitoring unit ( 3 ) is back in full operation, and the alarm is active.
[0040] This allows for full implementation of HVAC economizer modes without compromising fume hood safety, and, at the same time, allows the end user of a chemical fume hood to override HVAC economizer modes in order to conduct research in a safe environment, by disabling and/or enabling the fume hood alarm parameters during occupied or unoccupied periods.
[0041] FIG. 3 shows an implementation of the invention in a simpler form. As in FIG. 1 , a fume hood ( 1 ) has a fan ( 2 ) to draw air from the hood. The fan ( 2 ) is controlled by a controller ( 60 ), which could be a VSD, or simply an on/off power controller.
[0042] An airflow monitor and alarm unit ( 3 ) detects air flow in the hood ( 1 ) and sends a “low pressure” signal ( 29 ) to a Unitary Network Terminal (UNT) ( 62 ). The “alarm disable” line ( 28 ) is connected to an output of the UNT ( 62 ) A time clock ( 61 ) signals the UNT ( 62 ) as to the setback status (alternatively, the UNT might have an internal clock—it will be understood that the clock in the diagram could be separate or part of the UNT).
[0043] In operation, during the day cycle, the clock ( 61 ) signals the UNT ( 62 ) that the day cycle is active. The airflow monitor ( 3 ) is active, and the alarm is “on”, so if the air flow in the hood ( 1 ) drops below the preset minimum, the alarm in the monitor will go off. Optionally, the UNT ( 62 ) will detect the “low pressure” signal ( 29 ) and output an alarm message ( 63 ) through one of the methods known to the art, such as asserting an alarm on the facility bus, calling a pager on a dialer, or powering a remote alarm device.
[0044] When the night setback cycle starts, the clock ( 61 ) signals the UNT ( 62 ), which detects that the night cycle has begun from the clock signal, and asserts the “alarm disable” line ( 28 ) to shut off the alarm in the airflow monitor ( 3 ) and eliminate false “low pressure” signals ( 29 ).
[0045] The next level of complexity of the system would be to have the UNT ( 62 ) control the fan ( 2 ) through a setback line ( 64 ) to the fan controller ( 60 ). During the day cycle, the UNT ( 62 ) commands the fan controller ( 60 ) to turn on the fan ( 2 ). During the night setback cycle, the UNT ( 62 ) sends a setback signal on line ( 64 ) to cause the controller ( 60 ) to shut off the fan ( 2 ) (or reduce its speed). Alternatively, the clock ( 61 ) could assert the setback line ( 64 ) directly, instead of the line being an output of the UNT.
[0046] Additional devices can be added to the UNT, as desired, and the system can be expanded, within the teachings of the invention.
[0047] Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims of the non-provisional application which will be filed, which will themselves recite those features regarded as essential to the invention. | An air flow monitoring and control system with reduced false alarms includes an alarm sensor for monitoring air flow in a fume hood or the like, set to provide a warning if air flow drops below a predetermined amount. A local controller monitors the alarm, and disables it when the hood is set to reduced air flow, whether by a local timer or by command of a central control system. Optionally, the controller itself can operate a variable speed drive to reduce air flow on a timed basis, and the controller can communicate with facility management through a dialer or the Internet, or can interface with a central control for the facility through a facility bus. | 5 |
RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser. No. 14/155,233, filed on Jan. 14, 2014, which claims the benefit of and priority to U.S. Provisional Application Ser. No. 61/752,314, filed Jan. 14, 2013, the contents of which are hereby incorporated by reference as if recited in full herein for all purposes.
BACKGROUND
[0002] The innovations and related subject matter disclosed herein (collectively referred to as the “disclosure”) generally pertain to woven structures and associated systems for weaving such structures. Some aspects of disclosed innovations pertain to braided structures, such as braided wire structures, with a braided directional mesh being but one example. Other aspects of innovations disclosed herein pertain to methods of manufacturing woven structures, with an automated method of braiding a directional mesh being but one example. As but one example, some disclosed directional mesh structures constitute a portion of an energizable electrode configured for an electrosurgical therapy.
[0003] As used herein, the term “directional mesh” means an axially asymmetric woven structure. The sequence of drawings in FIGS. 1A, 1B and 1C shows a working embodiment of an innovative directional mesh.
[0004] Transurethral resection of the prostate (TURP) has been considered the reference ‘gold standard’ surgical procedure for low urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH). The high success rate of TURP as measured by substantial and sustained improvements of symptom scores, urinary flow rate and other functional parameters, remains associated with significant morbidity.
[0005] As a consequence, a number of minimally invasive therapeutic alternatives have been proposed during the last 30 years, including, inter alia, bipolar vaporization. Bipolar vaporization has shown promise as being an effective, safe and low-cost minimally invasive technique, providing very good hemostasis control and low complication rates. Suitable surgeon vision and hemostasis available during a bipolar vaporization procedure makes bipolar vaporization suitable for use in patients from high-risk groups, including those with cardiac pacemakers, bleeding disorders, or under anticoagulant therapy. Together with a relatively lower-cost per procedure compared to laser techniques, such advantages make bipolar vaporization an attractive technique for use in a variety of urological practice settings.
[0006] Bipolar vaporization techniques generate little heating of tissue surrounding a treatment site and are conducted without direct contact to tissue at a treatment site. In general, a bipolar electrode generates a thin plasma layer surrounding an electrically conductive portion of the electrode when an electrical current passes through the conductive portion. The plasma can vaporize a relatively thin layer of tissue at a treatment site on or in a patient's body without excessive heating (or other detrimental effect) of surrounding tissue.
[0007] To date, energizable electrodes have not allowed adjustments to their configuration during use. Nonetheless, an energizable electrode having an adjustable configuration can provide a surgeon with a variety of therapeutic options without having to replace or substitute one energizable electrode for another electrode having a different configuration.
[0008] Accordingly, there remains a need for an energizable electrode having an adjustable configuration. For example, there remains a need for an energizable electrode having a very compact profile to ease deployment of the electrode to a treatment site, being configured to expand to cover a relatively large area when deployed at or near the treatment site, and being further configured to contract to the compact profile for removal from the treatment site.
SUMMARY
[0009] The innovations disclosed herein overcome many problems in the prior art and address the aforementioned as well as other needs. By way of example, woven structures and associated systems for weaving such structures are disclosed. Some disclosed innovations pertain to braided structures, such as braided wire structures, with axially asymmetric woven structures (or “directional meshes”) being examples. Other innovations disclosed herein pertain to methods of manufacturing woven structures, with automated methods of braiding directional meshes being examples. Some directional mesh embodiments can be configured and used as energizable electrodes for electrosurgical therapies, for example, bipolar vaporization therapies.
[0010] According to a first innovative aspect, woven constructs are disclosed. A woven construct can include a plurality of interwoven wires defining an operative segment. The operative segment can have a longitudinal axis. Positioned radially outwardly of the longitudinal axis, the operative segment can have a region of relatively higher wire-density and a region of relatively lower density. The operative segment can be a braided directional mesh.
[0011] In some embodiments, the region of relatively higher wire-density and the region of relatively lower wire-density are asymmetrically positioned relative to the longitudinal axis. Such a configuration can allow the operative segment to buckle in a predetermined direction under a sufficient, longitudinally compressive load applied to the operative segment. As but one example, the predetermined direction can be substantially radially outward relative to the longitudinal axis.
[0012] In some embodiments the plurality of wires can also define opposed end portions, with the operative segment being positioned between the opposed end portions. A wire-pitch of the operative segment can be substantially lower than a wire-pitch of one or both of the opposed end portions.
[0013] Each of the wires can extend substantially helically around the longitudinal axis by between about 120 degrees and about 240 degrees, such as, for example, by between about 150 degrees and about 210 degrees.
[0014] The operative segment can be configured to generate a suitable plasma field for an electrosurgical therapy when a sufficient electrical current passes through the plurality of interwoven wires.
[0015] According to another aspect, braiding machines are disclosed. For example, a braiding machine can be configured to so interweave a plurality of wires as to define a braided directional mesh.
[0016] Such a braiding machine can be configured to vary a longitudinal pitch of the interwoven wires. For example, a first segment of the braided directional mesh can have a corresponding first longitudinal pitch and a second segment of the braided directional mesh can have a corresponding second longitudinal pitch being relatively higher than the first longitudinal pitch.
[0017] In some embodiments, a braiding machine can have a first plurality of wire carriers configured to orbit about a portion of the braiding machine in a first orbital direction, and a second plurality of wire carriers configured to orbit about the portion of the braiding machine in a second orbital direction generally opposite to the first orbital direction. Such a braiding machine can also be configured to interweave each wire carrier in the first plurality of wire carriers with each wire carrier in the second plurality of wire carriers to interweave the plurality of wires.
[0018] In a general sense, the first plurality of wire carriers can include n wire carriers, and the second plurality of wire carriers can include m wire carriers. At least one and fewer than all of the n wire carriers can be populated with a supply of wire. At least one and fewer than all of the m wire carriers can be populated with a supply of wire. Such a braiding machine configuration can as symmetrically interweave the plurality of wires.
[0019] In some embodiments, the supply of wire can include a bobbin containing a corresponding spool of wire, and the corresponding plurality of spools of wire can constitute the plurality of wires.
[0020] According to yet another aspect, methods of forming a directional mesh are disclosed. For example, such a method can include axially asymmetrically interweaving each of a first plurality of wires with each of a second plurality of wires.
[0021] According to some disclosed methods, the first plurality of wires can be substantially helically wound in a first direction around a longitudinal axis, and the second plurality of wires can be substantially helically wound in a second direction around the longitudinal axis. A circumferential component of the first direction relative to the longitudinal axis can be substantially opposite a circumferential component of the second direction relative to the longitudinal axis. A longitudinal component of the first direction relative to the longitudinal axis can be substantially identical to a longitudinal component of the second direction relative to the longitudinal axis.
[0022] According to some disclosed methods, a region of relatively higher wire-density can circumferentially oppose, relative to the longitudinal axis, a region of relatively lower wire density. The region of relatively higher wire-density and the region of relatively lower wire-density can be configured such that the woven first and second pluralities of wires are configured to buckle in a predetermined direction under a sufficient, longitudinally compressive load.
[0023] According to some disclosed methods, an operative segment can be formed between opposed end segments. The operative segment can have a relatively lower pitch than either of the opposed end segments. In the operative segment, each of the plurality of wires can extend substantially helically around the longitudinal axis by between about 120 degrees and about 240 degrees, with between about 150 degrees and about 210 degrees being but one example of a suitable range of winding.
[0024] According to some disclosed methods, a directional mesh can be configured to generate a suitable plasma field for an electrosurgical therapy when a sufficient electrical current passes through the plurality of interwoven wires.
[0025] According to some disclosed methods, a longitudinal pitch of the interwoven wires can be varied. For example, a first segment of the directional mesh can have a corresponding first longitudinal pitch, and a second segment of the directional mesh can have a corresponding second longitudinal pitch being relatively higher than the first longitudinal pitch.
[0026] According to some methods, the act of interweaving each of the first plurality of wires with each of the second plurality of wires can include orbiting a first plurality of wire carriers about an orbital center in a first orbital direction and orbiting a second plurality of wire carriers about the orbital center in a second orbital direction. The second orbital direction can be in a direction generally opposite to the first orbital direction.
[0027] According to some methods, the first plurality of wire carriers can include n wire carriers and the second plurality of wire carriers can include m wire carriers. At least one and fewer than all of the n wire carriers can be populated. At least one and fewer than all of the m wire carriers can be populated. Each populated wire carrier can include a bobbin containing a corresponding spool of wire. A given plurality of spools of wire can constitute a respective plurality of wires.
[0028] The foregoing is not intended to be an exhaustive list of embodiments and features of the inventive subject matter. The appended claims, as originally filed in this document, or as subsequently amended, are hereby incorporated into this Summary section as if written directly in. Persons skilled in the art are capable of appreciating other embodiments and features from the following detailed description in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Unless specified otherwise, the accompanying drawings illustrate aspects of the innovative subject matter described herein.
[0030] FIGS. 1A, 1B and 1C form a sequence of drawings showing a working embodiment of a directional mesh.
[0031] FIG. 2 shows an isometric view of an example of a woven structure of the type disclosed herein.
[0032] FIG. 3 shows a schematic illustration of a braiding machine configuration suitable for manufacturing a directional mesh.
[0033] FIGS. 4A, 4B, 4C and 4D schematically illustrate a sequence of braiding machine configurations during a braiding process.
[0034] FIGS. 5A, 5B, 5C and 5D schematically illustrate a sequence of braiding machine configurations during a directional mesh braiding process.
[0035] FIGS. 6A and 6B are drawings of a working embodiment of a braiding machine as described herein. FIG. 6B shows a carrier populated with a bobbing having a spool of wire.
[0036] FIG. 7 is a drawing of an unpopulated carrier separate from and suitable for use with a braiding machine as shown in FIG. 6A .
DETAILED DESCRIPTION
[0037] The following describes various principles related to woven structures and associated systems by way of reference to specific examples of braided structures and associated systems. In some innovative embodiments, a directional mesh constitutes a portion of an energizable electrode configured for electrosurgical therapy.
[0038] One or more of the principles can be incorporated in various system configurations to achieve any of a variety of system characteristics. Systems described in relation to particular configurations, applications, or uses, are merely examples of systems incorporating the innovative principles disclosed herein and are used to illustrate one or more innovative aspects of the disclosed principles. Accordingly, woven structures and associated systems having attributes differing from those specific examples discussed herein can embody one or more of the innovative principles. Accordingly, such alternative embodiments also fall within the scope and spirit of this disclosure.
Overview
[0039] An innovative woven structure can have an axial asymmetry or other characteristic adapted to cause the structure to buckle asymmetrically when sufficiently compressed axially. The sequence of drawings shown in FIGS. 1A, 18 and 1C illustrate a specific example of asymmetric buckling of a braided wire mesh.
[0040] As shown in FIG. 1A , the undeformed mesh 100 is axially asymmetric, having a region 105 of relatively higher wire density positioned circumferentially opposite a region 110 of relatively lower wire density. When longitudinally axially compressed sufficiently to buckle, the mesh 100 expands in a circumferentially asymmetric manner to form a bulge 115 extending radially outwardly of the longitudinal axis 120 . Such a mesh is sometimes referred to as having a “directional” property insofar as the mesh 100 expands in generally one direction, as opposed to a circumferentially symmetric mesh that would tend to expand uniformly relative to the circumference, e.g., radially outward in all directions.
[0041] The directional mesh shown in FIGS. 1A, 1B, and 1C is configured as an energizable, bipolar electrode suitable for use in providing an electrosurgical therapy. The pictured directional mesh defines an operative segment 125 of the energizable electrode and is configured to extend between and electrically couple with opposed electrodes 130 a, b. The opposed electrodes, in turn, are configured to urge toward each other and thereby apply a longitudinally compressive load to the operative segment 125 . Such an electrode configuration can permit a surgeon to tailor the electrode configuration in situ to suit a given therapy without having to withdraw the electrode from a treatment site.
[0042] In some embodiments, a catheter or other electrosurgical device used in combination with disclosed energizable electrodes can be configured to limit the extent of longitudinal compressive or tensile displacement. Such a configuration can help ensure that the maximum stress within the energizable electrode remains sufficiently below the respective material's yield strength.
Woven Constructs
[0043] As shown in FIG. 2 , a woven construct 200 can be formed from a plurality of interwoven, biocompatible, electrically conductive wires 201 defining an operative segment 225 positioned between opposed end segments 231 a, b. The operative segment 225 has a longitudinal axis (not shown). Positioned radially outwardly of the longitudinal axis, the operative segment 225 defines a region 205 of relatively higher wire-density and a region 210 of relatively lower density, similar to the working embodiment 100 pictured in FIGS. 1A, 1B, and 1C .
[0044] Some disclosed energizable electrodes can be formed from a material having relatively high yield strength to permit the energizable electrode to change configurations without undergoing a plastic deformation. For example, some suitable materials can elastically deform between a compact configuration suitable for deploying the electrode (e.g., shown in FIG. 1A ) and an expanded configuration (e.g., shown in FIG. 1C ) suitable for electrosurgical therapies.
[0045] As but several examples, suitable materials for innovative electrosurgical electrodes can include an alloy of stainless steel, copper beryllium or platinum iridium. In some embodiments, a suitable wire can have a diameter of between about 0.005 inch and about 0.007 inch (inclusive). Well-suited materials for electrosurgical applications exhibit durability under repetitive cycles of energization and de-energization with RF electrical energy. As but one particular, but not exclusive, example, platinum can be well-suited for electrosurgical applications.
[0046] For applications that do not require electrical energization, high-strength polymer materials can be suitable. As an example, Kevlar can be a suitable material.
[0047] The region 205 of relatively higher wire-density and the region 210 of relatively lower wire-density are asymmetrically positioned relative to the longitudinal axis. Such a configuration permits the operative segment 225 to buckle in a predetermined direction under a sufficient, longitudinally compressive load applied to the operative segment. As shown in the sequence of drawings in FIGS. 1A, 1B, and 1C , the predetermined direction can be substantially radially outward relative to the longitudinal axis (e.g., axis 120 ).
[0048] As shown in FIG. 2 , a wire-pitch of the operative segment 225 is substantially lower than a wire-pitch of one or both of the opposed end portions 231 a, b. As used herein, “wire-pitch” refers to a ratio of a measure of a given wire's circumferential winding to a measure of length. In some instances, the measure of length can be measured relative to the resulting construct (e.g., a directional mesh 100 , 200 ) and in other instances the measure of length can be measured relative to the wire (e.g., a length of the wire 201 ). As but one example, a given wire-pitch of a wire extending about half-way around a longitudinal axis in one centimeter could be 0.5 windings per centimeter. Another, relatively higher wire-pitch could be 2 windings per centimeter.
[0049] In a general sense, regions of a woven construct 200 outside the operative segment 225 can be woven to a suitably high pitch (e.g., approaching a “solid tubular” construct). As but one example, a 0.041 inch mandrel was used to weave a 0.005 inch diameter wire at a pitch of about 130 windings per inch (PPI) (e.g., between about 120 PPI and about 140 PPI) for regions outside of the operative segment 225 . In contrast, the operative segment 225 was woven at about 1-3 PPI over a distance of between about 0.3 inch to about 0.4 inch. A woven construct 200 can include a plurality of operative segments 225 juxtaposed with a corresponding plurality of outside regions 231 a, b. Each outside region 231 a, b of the woven construct 200 can be cut to separate individual energizable electrodes from the woven construct 200 . The outside regions 231 a, b can be trimmed to a selected length.
[0050] As shown in FIG. 2 , each of the wires 201 extends substantially helically around the longitudinal axis, though each wire is interwoven with several other wires causing the wires to depart slightly from a pure helical winding. In the operative segment 225 , the wires extend circumferentially around the longitudinal axis by about 180 degrees, for example between about 120 degrees and about 240 degrees, such as between about 150 degrees and about 210 degrees. Stated differently, a distal end of a given helical wire 201 in the operative segment 225 is circumferentially offset from the corresponding proximal end by about 180 degrees, for example between about 120 degrees and about 240 degrees, such as between about 150 degrees and about 210 degrees.
Interweaving
[0051] A directional mesh can be formed by axially asymmetrically interweaving each of a first plurality of wires 201 with each of a second plurality of wires 201 .
[0052] For example, as shown schematically in the sequence of illustrations in FIGS. 4A, 4B, 4C and 4D , a braiding machine 10 can interweave each of a first plurality of wires (or wire carriers, for example, bobbins having respective spools of wire) 13 a with each of a second plurality of wires (or wire carriers, for example, bobbins having respective spools of wire) 13 b. In particular, the braiding machine 10 has a platen 11 having a bi-directional track 12 a, 12 b configured to urge the first plurality of wires 13 a generally clockwise through a nominal orbit 16 relative to the platen 11 and to urge the second plurality of wires 13 b generally counter-clockwise through the nominal orbit 16 .
[0053] In the example shown in FIGS. 4A, 4B, 4C and 4D , the orbital paths defined by the tracks 12 a, 12 b oscillate radially relative to the platen 11 about the nominal orbit 16 . The tracks 12 a and 12 b intersect at, for example, intersection 12 c. The bi-directional track 12 a, 12 b causes the wires 13 a to interweave with the wires 13 b as the wires 13 a, 13 b travel through their respective orbital paths. Motion of the wires 13 a, 13 b along each portion of the tracks 12 a, 12 b is indicated by the arrows 14 a, 14 b. FIG. 4B shows an intermediate configuration of a braiding machine 10 , as well as relative positions of first and second pluralities of wires 13 a, 13 b, after each rotatable portion of the bi-directional track 12 a, 12 b has advanced by about 90 degrees relative to the position shown in FIG. 4A . FIG. 4C shows the braiding machine 10 and wires 13 a, 13 b after the bi-directional track 12 a, 12 b has advanced by about 90 degrees relative to the position shown in FIG. 4B . FIG. 4D shows the braiding machine 10 and wires 13 a, 13 b after the bi-directional tracks 12 a, 12 b have advanced by about 90 degrees relative to the position shown in FIG. 4C . As the wires 13 a, 13 b pass through their respective counter-directional orbits, the interweaving of the wires 13 a, 13 b forms a woven construct adjacent an orbital center, similar to woven ribbons wound about a maypole.
[0054] As noted above in relation to FIGS. 4A, 4B, 4C and 4D , some braiding machines 10 interweave first and second pluralities of spools of wire 13 a, 13 b. More particularly, some braiding machines 10 are configured to withdraw a woven construct from the orbital center of the platen 11 (e.g., in a direction generally perpendicular to the platen 11 ).
[0055] Wire-pitch of a woven construct formed using an approach as summarized above is proportional to orbital speed (e.g., number of orbits per unit of time) of the wires (or carriers) 13 a, 13 b and inversely proportional to a speed at which the woven construct is withdrawn, e.g., from the braiding machine. Accordingly, if a rate at which the woven construct is withdrawn increases and the orbital speed of the wires 13 a, 13 b remains constant, the resulting construct will have a relatively lower wire-pitch. Conversely, if a rate at which the woven construct is withdrawn decreases and the orbital speed of the wires 13 a, 13 b remains constant, the resulting construct will have a relatively higher wire-pitch. Thus, the construct shown in FIG. 2 can be formed by withdrawing the construct at a relatively lower rate while the end segments 231 a, b are being woven, and withdrawing the construct at a relatively higher rate while the operative segment 225 is being woven.
[0056] The mesh design and the set-up of the braider to produce the design enable the directional mesh shown in FIGS. 1A-C and 2 to be made in a continuous process on a multi-carrier braiding machine as depicted in FIGS. 4A-D , 5 A-D and 6 . For example, a continuous woven construct can comprise a plurality of operative segments 225 juxtaposed with a plurality of end segments 231 a, b. The continuous woven construct can be segmented (e.g., each end segment 231 a, b can be bisected to form one woven construct 200 having an operative segment 225 positioned between opposed end segments 231 a, b, as shown in FIG. 2 .)
[0057] Withdrawing a woven construct formed from the orbiting wires (or carriers) 13 a, 13 b can cause the first plurality of wires 13 a to be substantially helically wound in a first direction around a longitudinal axis, and the second plurality of wires to be substantially helically wound in a second direction around the longitudinal axis. With the counter-orbits described above, a circumferential component of the first direction relative to the longitudinal axis is substantially opposite a circumferential component of the second direction relative to the longitudinal axis, while a longitudinal component of the first direction relative to the longitudinal axis is substantially identical to a longitudinal component of the second direction relative to the longitudinal axis.
[0058] An asymmetrically loaded braiding machine 10 , as shown in FIGS. 5A-D can interweave a plurality of wires to define a braided directional mesh of the type shown in FIGS. 1A, 1B, 1C, 1 d and 2 . In particular, operating an asymmetrically loaded braiding machine can form a woven construct having a region of relatively higher wire-density circumferentially opposing, relative to a longitudinal axis, a region of relatively lower wire density.
[0059] For example, as shown in FIGS. 3, 4A, 4B, 4C, and 4D , a braiding machine 10 can have 16 wire carriers, with 8 wire carriers configured to orbit generally in a clockwise direction relative to the platen 11 and 8 wire carriers configured to orbit generally in a counter-clockwise direction relative to the platen 11 . In FIGS. 3 and 5A, 5B, 5C and 5D , fewer than all available wire carriers (and at least one carrier corresponding to each orbital direction) populate the platen 11 asymmetrically.
[0060] For example, in FIG. 3 , several populated wire carriers, R, configured to orbit in a generally clockwise direction relative to the platen 11 are juxtaposed with unpopulated wire carriers configured to orbit in the same direction. Similarly, several populated wire carriers, L, configured to orbit in a generally counter-clockwise direction relative to the platen 11 are juxtaposed with unpopulated wire carriers configured to orbit in the same direction. The asymmetry is introduced insofar as a populated carrier R is positioned adjacent a populated carrier L, and counter-orbiting, unpopulated carriers 11 a, b are positioned adjacent to each other. Such an asymmetric loading of a braiding machine can form a directional mesh construct as shown in FIGS. 1A, 1B, 1C and 2 .
[0061] Although 16-carrier braiding machines have been described by way of example, above, similar principles apply to any braiding machine having a first plurality of wire carriers configured to interweave with a counter-orbiting second plurality of wire carriers. For example, the first plurality of wire carriers can include n wire carriers and the second plurality of wire carriers can include m wire carriers. At least one and fewer than all of the n wire carriers can be populated, and at least one and fewer than all of the m wire carriers can be populated, and the braiding machine can thereby be configured to asymmetrically interweave the first plurality of wire carriers with the second plurality of wire carriers to form a directional mesh.
Other Exemplary Embodiments
[0062] The embodiments described above generally concern woven structures configured to buckle in a predetermined direction. Nonetheless, other embodiments are possible. For example, a coil spring can be bowed outwardly. Such a coil spring can, in some embodiments, have a longitudinally variable coil pitch (e.g., a segment of the spring can be plastically deformed, or “stretched,” to impart the segment with a relatively lower pitch). A region of relatively lower pitch can be urged together to bow outwardly. In another alternative embodiment, one or more apertures can be cut into a tubular metal structure (e.g., by laser cutting), defining a segment of the tubular metal structure configured to buckle in a predetermined direction under a longitudinally compressive load.
[0063] This disclosure references the accompanying drawings, which form a part hereof, wherein like numerals designate like parts throughout. The drawings illustrate specific embodiments, but other embodiments may be formed and structural and logical changes may be made without departing from the intended scope of this disclosure.
[0064] Directions and references (e.g., up, down, top, bottom, left, right, rearward, forward, etc.) may be used to facilitate discussion of the drawings but are not intended to be limiting. For example, certain terms may be used such as “up,” “down,”, “upper,” “lower,” “horizontal,” “vertical,” “left,” “right,” and the like. Such terms are used, where applicable, to provide some clarity of description when dealing with relative relationships, particularly with respect to the illustrated embodiments. Such terms are not, however, intended to imply absolute relationships, positions, and/or orientations. For example, with respect to an object, an “upper” surface can become a “lower” surface simply by turning the object over. Nevertheless, it is still the same surface and the object remains the same. As used herein, “and/or” means “and” or “or”, as well as “and” and “or.”
[0065] All patent and non-patent literature cited herein is hereby incorporated by references in its entirety for all purposes. Incorporating the principles disclosed herein, it is possible to provide a wide variety of systems configured to render an electrosurgical handpiece inoperable at or near an end of the handpiece's safe useful life, in addition to the systems described above.
[0066] The technologies from any example can be combined with the technologies described in any one or more of the other examples. Accordingly, this detailed description shall not be construed in a limiting sense, and following a review of this disclosure, those of ordinary skill in the art will appreciate the wide variety of electrosurgical systems that can be devised using the various concepts described herein. Moreover, those of ordinary skill in the art will appreciate that the exemplary embodiments disclosed herein can be adapted to various configurations without departing from the disclosed principles. Thus, in view of the many possible embodiments to which the disclosed principles can be applied, it should be recognized that the above-described embodiments are only examples and should not be taken as limiting in scope. Therefore, I claim all that comes within the scope and spirit of the following claims, and reserve the right to claim in the future any or all aspects of any innovation shown or described herein. | Woven structures and associated systems for weaving such structures are disclosed. Some disclosed innovations pertain to braided structures, such as braided wire structures, with axially asymmetric woven structures (or “directional meshes”) being examples. Other innovations disclosed herein pertain to methods of manufacturing woven structures, with automated methods of braiding directional meshes being examples. Some directional mesh embodiments can be configured and used as energizable electrodes for electrosurgical therapies, for example, bipolar vaporization therapies. | 3 |
The present invention relates to a method of slip-forming a roadbed and a curb or curbs of concrete material and to slip-forming apparatus for carrying out such a method.
Slip-forming, i.e., the use of formwork carried by a moving structure or platform is widely used for the laying of concrete roadbeds and is also used for forming curbs. Such moving platforms are usually supported on some form of motorized supports, such as tracks, wheels and the like. The width of a concrete roadbed that can be laid down by such an apparatus is usually determined by the space between the tracks or wheels of such apparatus. Where the road site is unobstructed on both sides, it is of course possible to separate the tracks of the apparatus far enough apart for the slip-form to shape both the curbs and the roadbed itself simultaneously in a single pass.
However, in many locations, such as, for example, in city streets, the roadway will be obstructed on one side or the other. In such cases, existing slip-forming methods require that the track portions of the platform run at least partly in the location where the curbs or the roadbed will eventually be formed. After the roadbed has been formed, there will then be two spaces, one on either side and separate slip-forming equipment must then be driven along the roadbed itself to slip-form the curbs or even other parts of the roadbed.
This known procedure involves three separate operations or passes instead of one and also means that the roadbed and curbs are formed with breaks or spaces between them and are not a single integral structure. This of course leads to inherent weakness and water, salt and the like can enter into such openings and damage the concrete, making the final structure less durable.
It is clearly, therefore, desirable to form the roadbed and curbs in a single pass, both from the viewpoint of efficiency and economy and also from the viewpoint of durability.
SUMMARY OF THE INVENTION
The present invention therefore seeks to overcome the foregoing disadvantages by the provision of a method of slip-forming a roadbed and at least one integral curb by the steps of (a) moving a roadbed slip-form along one side of a trackway and simultaneously moving a curb slip-form along an opposite side of said track way, said roadbed slip-form and said curb slip-form being mutually spaced apart by a distance equalling at least the width of said trackway, (b) continuously depositing concrete material in front of both said roadbed slip-form and said curb slip-form whereby movement of said slip-forms over said concrete material will shape and form said concrete material into a roadbed and a curb, said roadbed and said curb so formed being mutually spaced apart by a predetermined gap, (c) continuously passing a filler portion of concrete material through one of said roadbed slip-form and said curb slip-form, said filler portion of concrete material being disposed on the top surface of concrete material formed by a respective one of said slip-forms and being located generally along one edge of and on one of said roadbed and said curb adjacent said gap, (d) continuously transferring said filler portion of concrete material transversely into said gap thereby filling said gap to join said curb and said roadbed to form a single integral homogeneous concrete structure, and (e) continuously smoothing the top surface of said concrete material as transferred into said gap and the top surface of that one of said curb and said roadbed from which said filler portion was transferred.
In general, the continuous deposition of concrete material in front of the curb slip-form will be effected by continuously transferring concrete material into such position from its position as dumped or deposited in front of the roadbed slip-form. Such transfer of concrete material is usefully effected over said trackway, for example, by the use of an elevator.
The method according to the invention further envisages the forming of two curbs on opposite sides of a roadbed in the same way simultaneously.
Preferably, in accordance with this invention the filler portion of concrete is located initially on said roadbed and is transferred from such location on such roadbed into the gap between the roadbed and the curb.
The method according to the invention usefully further comprises the continuous rearranging of concrete material as deposited in front of the roadbed slip-form so as to obtain a more or less even distribution thereof and so as to ensure that sufficient concrete material is distributed or transferred toward at least one side of the roadbed so that some of such concrete material may be conveyed over the space occupied by the track portions of the platform and into the slip-form for the curb and so that, in addition, a sufficient excess of concrete material is available at the edge of the roadbed so that it may subsequently be transferred therefrom for filling the gap left by the corresponding track portion.
The invention also provides an apparatus for carrying out the aforementioned objectives. Such apparatus can broadly be defined as comprising transversely spaced apart support means movable in a longitudinal direction along a roadway sub-surface; a roadbed slip-form extending transversely between said support means, supported thereby and adapted to shape and form fluid concrete material as deposited in front thereof into a roadbed having a top surface; a curb slip-form located transversely adjacent a first one of said support means and supported thereby so as to be spaced apart transversely relative to said roadbed slip-form by a gap having a width at least equal to the width of said first one of said support means and adapted to shape and form fluid concrete material as deposited in front thereof into a curb having a top surface; a rearward passage for continuously passing a filler portion of concrete material through one of said roadbed slip-form and said curb slip-form, said filler portion of concrete material being disposed on the top surface of a respective one of said roadbed and said curb; a transverse transfer means for transferring such a filler portion of concrete material into said gap rearwardly of said first one of said support means; and smoothing means supported by said support means and adapted to smooth both the top surface of said concrete material as transferred into said gap and the top surface of that one of said curb and said roadbed from which said filler portion was transferred.
An apparatus in accordance with this invention will generally also comprise a transfer feed means supported by said support means and adapted to transfer concrete material from a position in front of said roadbed slip-form to a position in front of said curb slip-form. Such a transfer feed means is usefully in the form of an elevator adapted to transfer concrete material transversely outwardly to said curb slip-form over the path of said first one of said support means.
The invention further provides that the apparatus may be provided with curb slip-forms at both sides thereof and usefully with transfer feed means for conveying concrete material to both curb slip-forms simultaneously.
The apparatus according to the invention will of course normally be provided with a suitable guidance and height adjustment system, as is provided in other such mobile platforms. Additionally, such an apparatus is preferably provided with concrete spreader or distributor means across its front so that concrete material may be dumped in front of the platform and then spread outwardly to both sides.
In addition, the usual concrete vibrators will be incorporated at various points so as to ensure free movement of the concrete material and complete filling of the slip-forms.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described merely by way of illustration with reference to the accompanying drawings, in which:
FIG. 1 is a schematic perspective illustration showing one embodiment of a slip-forming apparatus in accordance with this invention;
FIG. 2 is a top plan view of one side of the slip-forming apparatus shown in FIG. 1 when taken as indicated by the arrows 2--2 of that figure and with certain parts cut away to reveal underlying structure;
FIG. 3 is a vertical section along the line 3--3 of FIG. 2;
FIG. 4 is a vertical section along the line 4--4 of FIG. 2;
FIG. 5 is a vertical section along the line 5--5 of FIG. 2; and
FIGS. 6a, 6b and 6c are schematic views showing three steps in the method according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIGS. 6a, 6b and 6c, the method according to the invention is illustrated schematically. In FIG. 6a, a mass M of fluid concrete material is shown as being deposited on a roadway sub-surface S.
In FIG. 6b, the mass of concrete material is shown as having been slip-formed to provide a central roadbed portion R and two curb portions C of concrete material on opposite sides of the roadbed portion R but spaced therefrom by gaps G. The gaps G have widths which correspond more or less to the widths of the spaced apart support means of the apparatus used for slip-forming the roadbed R and the curbs C and which will be described in more detail below. Two filler portions F of concrete material formed by depositing an excess of concrete on top of the central roadbed portion R, along both sides thereof, are provided, being generally sufficient to fill respective ones of the gaps G.
In FIG. 6c, the final step of the method according to the invention is shown. In that step, the two filler portions F of concrete material are transferred from their positions on top of the roadbed R into the gaps G.
Reference will now be made to FIG. 1 which shows one embodiment of an apparatus according to the invention. That apparatus which is essentially a very large vehicle, having suitable mobile support means, typically track or crawler type support means T carrying vertically adjustable columns A, typically hydraulic cylinders which support a platform P, will normally be provided with any suitable drive and transmission means (not shown). The height and direction of the platform P are controlled by means of a guideline L supported on suitable pegs alongside the road sub-surface S. One or more guide heads H may be mounted on the side of the platform P for following the line L. Such guide heads H may simply provide a visual check of the position of the platform P. Alternatively, automatic sensing means may be provided for sensing any deviation of the platform P from the line L and for causing suitable adjustments to either height or direction to be made automatically in a manner known in the art.
Referring now to FIGS. 2, 3, 4 and 5, the platform P will be seen to be provided with a central roadbed slip-form 10 which is located between the tracks T of the platform P.
The slip-form 10 comprises an upper wall portion 12, front guide walls 13 extending forwardly and more or less vertical side walls 14 extending rearwardly on opposite transverse sides thereof. In order to provide a passageway for passage of the filler portions F, angular wall portions 16 and 17 are fastened between the top wall 12 and the side walls 14 on both sides of the roadbed slip-form 10. The angular wall portions 16 and 17 will be seen to provide generally upwardly projecting box-like enclosures having open bottoms communicating with the lower portion of the slip-form 10 so that the filler portions F of concrete material may pass therethrough above the general level of the roadbed R.
It may also be desirable to provide guard walls or baffles (not shown) in front of the leading tracks T to keep this area free of concrete but in most cases this is not necessary.
The side walls 14 are located closely adjacent to the inner edges of the tracks T of the platform so that the roadbed may be slip-formed over the full transverse extent of the space between the tracks T.
The passage-forming wall portions 16 and 17 are somewhat shorter than the length of the top wall 12 of the slip-form 10, and are closed off at their rear ends by end walls 18. It will be noted that the lengths of the walls 16 and 17 are such as to extend somewhat beyond the rearmost limit of the rearward track T of the platform, so that the filler portion of concrete material is carried to a position rearward of that rearward track T.
In order to slip-form the curb C, curb slip-forms shown generally at 20 are provided on opposite transverse sides of the platform P, such curb slip-forms being located transversely outwardly with respect to the tracks T. Such a curb slip-form 20 will be seen to comprise an upper or top wall 22 and outer and inner side walls 24 and 25 respectively. The shape of the upper wall 22 may be such as to provide any suitable curb profile depending upon the requirements of the particular highway being constructed. Some such curb profiles provide simply a generally concave gutter shape while other such curb profiles provide a shape as shown, the precise shaping of the curb, however, forming no part of the present invention.
The curb slip-forms 20 also extend rearwardly of the rearmost tracks T of the platform P.
A transverse transfer passage 26 consisting of an upper wall 28 and two transverse side walls 32 extends from the angular wall portions 16 and 17 to a point adjacent the respective curb slip-form 20, being closed off at about its free end by means of an end wall 34.
The transfer passageway 26 thus leaves a generally rectangular downwardly directed port 36 through which the concrete material may be transferred downwardly into a respective one of the gaps G between the curb C and the roadbed R. Such ports 36 will thus be located more or less directly in line with the respective track T of the platform P as shown in the drawing.
As hereinbefore mentioned, in this particular embodiment of the present invention, the mass of concrete material M is initially deposited between the tracks T of the platform, the amount of such concrete material being sufficient both for slip-forming the roadbed R, the filler portions F and the curbs C.
In order to transfer concrete material from such mass into the curb forms 20, generally cylindrical tubular conveyor conduits 38 are mounted in front of the roadbed slip-form 10 so as to extend upwardly and outwardly at an angle with their inner ends being more or less at ground level and extending upwardly and outwardly over the tracks T. Within the conduits 38, any suitable conveyor means such as, for example, augers 40, are provided, which augers are driven by any suitable motor drive means 41 which may, for example, be hydraulic or pneumatic. Operation of the augers 40 will cause a portion of the concrete mass M to be driven up the conduits 38 and over the tracks T and to be ejected from the upper ends of the conduits over the curb slip-forms 20. The curb slip-forms 20 are preferably provided with hoppers 42 located more or less directly beneath the upper ends of the conduits 38 so as to catch concrete material falling therefrom and to feed it downwardly into the curb slip-forms 20.
Preferably, means will also be provided for distributing the concrete material evenly in front of the roadbed slip-form 10. In FIG. 2, augers 44 located more or less in a horizontal transverse manner in front of the slip-form 10 are shown as being provided for such purpose. The augers 44 may, in fact, be mounted on a single shaft and comprise helical spiral members wound in opposite directions so that, upon rotation of the shaft, concrete will be spread from the centre outwardly in both directions. Such a shaft would be driven by any suitable motor means (not shown) such as are well known in the art.
Any suitable concrete vibrator means 46 may be located at various points in the slip-forms 10 and 20 and driven by any suitable motor means (not shown) such as are well known in the art and require no further description herein.
In order to provide transfer of the concrete filler portions F from their initial locations above the edges of the roadbed R into the gaps G, transfer auger means 48 are provided within the transfer passageways 26 and such auger means 48 can be driven by any suitable motor means 49 such as are well known in the art. Such auger means 48 will be operable to move the filler portions of concrete material transversely outwardly through the passageways 26 so that such portions then drop downwardly through the ports 36 into the gaps G.
Horizontal top walls 50 extend rearwardly from passageways 36 for smoothing the top surface of the filler concrete. Smoothing bars 54 may also be added at the rear of top wall 12 for smoothing the surface of roadbed R.
In operation, the mass M of concrete material is deposited in front of the roadbed slip-form 10 from a truck, the platform P is set in motion forwardly and the various augers and motors and vibrators are started. The concrete material is distributed toward the sides of the slip-form 10 continuously by operation of the augers 44 and some of the concrete material is transferred continuously upwardly through the conduits 38 by the augers 40, so that some concrete is continuously transferred over the paths of the tracks T and deposited in the hoppers 42 of the curb slip-forms 20. If desired, of course, concrete material may initially be placed in the hoppers 42 by hand so that the forward movement of the platform will simultaneously commence slip-forming both of the roadbed R and the curbs C at the same position.
Some of the concrete material will pass directly under the top wall 12 of the roadbed slip-form 10 so as to be shaped and formed into the actual surface of the roadbed R.
Excess concrete material will pass through the passageway defined by the walls 14, 16 and 17 above the roadbed R so as essentially to be disposed above that roadbed.
The front walls 13 and side walls 14 and 25 prevent concrete from entering beneath the tracks T with the result that the gaps G are formed along either side of the roadbed R.
Simultaneously with the slip-forming of the roadbed R, the curbs C are of course being continuously slip-formed as the platform P moves forwardly, by passage of portions of the concrete material through the curb slip-forms 20.
The filler portions of concrete material finally reach the transfer passageways 26 and are then moved transversely outwardly relative to the roadbed R by the augers 48 in the passageways 26 until such filler portions reach the downwardly directed ports 36, at which point such material will drop downwardly into the gaps G formed between the roadbed R and the curbs C. The upper surface of such excess concrete is then smoothed and slip-formed by the upper walls 50 which extend rearwardly with respect to the passageway 26 and also by bars 54, so as to smooth the entire surface of the roadbed from side to side between the curbs C.
If desired, any suitable form of vibratory or rotary finishing devices (not shown) of a type well known in the art may be incorporated in both the roadbed slip-form 10 and the curb slip-forms 20 so as to provide a smooth finished appearance. Alternatively, the surface may be hand-trowelled or finished by manually held machines in any suitable manner.
The profile of the curbs C will, generally speaking, be such that, provided a suitable form of low-slump concrete is used, they will not sag or collapse after they leave the curb slip-forms 20.
Clearly, it would also be possible, if the curbs C were sufficiently wide, to pass the filler portions F of concrete material through suitable passages provided on top of the curbs. Such filler portions of concrete material would then be moved transversely inwardly into the gaps G provided for the tracks T, in essentially the same way as hereinbefore described. Such an alternative arrangement is not, therefore, to be regarded as being excluded from the scope of the invention. The terms "roadbed" and "curb" as used herein are not intended to exclude such an alternate form of operation, although the mode as illustrated herein is believed to be convenient and effective in practice.
The foregoing is a description of a preferred embodiment of the invention which is given here by way of example only. The invention is not to be taken as limited to any of the specific features as described, but comprehends all such variations thereof as come with in the scope of the appended claims. | A roadbed and a curb are formed as a single integral structure by slip-forming concrete material using a tracked vehicle supporting a roadbed slip-form and a curb slip-form which extend along opposite sides of a track of the vehicle so leaving a gap between the formed roadbed and curb to allow passage of the vehicle track. A filler portion of concrete material passes rearwardly through a passageway in the roadbed slip-form above the final top surface of the roadbed and such filler portion of concrete material is transferred transversely outwardly to fill such a gap rearwardly of the vehicle track. Finally, the top surface of the material so transferred and that of the roadbed from where such material was transferred are smoothed. | 4 |
TECHNICAL FIELD
This invention relates to a process for the preparation of Lapatinib (I) and its ditosylate salt thereof.
BACKGROUND
Lapatinib is a member of the 4-anilinoquinazoline class of kinase inhibitors. It is marketed in the USA as TYKERB® (Lapatinib) and is indicated in combination with: Capecitabine for the treatment of patients with advanced or metastatic breast cancer whose tumors overexpress HER2 and who have received prior therapy including an anthracycline, a taxane, and Trastuzumab and Letrozole for the treatment of postmenopausal women with hormone receptor positive metastatic breast cancer that overexpresses the HER2 receptor for whom hormonal therapy is indicated. Lapatinib inhibits ErbB-driven tumor cell growth in vitro and in various animal models. Lapatinib is present as the monohydrate of the ditosylate salt, with the chemical name N-[3-chloro-4-[(3-fluorophenyl)methoxy]phenyl]-6-[5[[[2-(methylsulfonyl)ethyl]amino]methyl]-2-furanyl]-4-quinazolinaminebis(4-methylbenzenesulfonate)monohydrate.
U.S. Pat. No. 6,713,485 relates to substituted heteroaromatic compounds, methods for their preparation, pharmaceutical compositions containing them and their use in medicine. Specifically, the invention relates to quinazoline derivatives useful in treating disorders mediated by protein tyrosine kinase activity, in particular erbB-2 and/or EGFR activity
WO 2002/02552 discloses ditosylate salts of 4-quinazolineamines as well as methods of using the same in the treatment of disorders characterized by aberrant erbB family PTK activity.
WO 2010/017387 provides Lapatinib intermediates and improved processes for preparing Lapatinib intermediates. The invention also provides processes for preparing Lapatinib and Lapatinib ditosylate.
WO 2010/061400 relates to an improved and novel process for the preparation of high purity crystalline base of Lapatinib and its pharmaceutically acceptable salts. The invention further relates to intermediates according to formula (8) and formula (9) used in this process.
SUMMARY
The present invention is directed to a process for the preparation of Lapatinib and its pharmaceutically acceptable salts.
Illustrative embodiments of the present invention provide a process for the preparation of Lapatinib or a ditosylate salt thereof comprising: i) treating of a compound of Formula II:
with 2-methanesulphonylethylamine or a salt thereof, thereby forming a product; and ii) reducing the product in the presence of a suitable hydrogenation catalyst, thereby forming Lapatinib free base of Formula IV:
Illustrative embodiments of the present invention provide a process described herein further comprising converting the compound of Formula IV to Lapatinib ditosylate of Formula I:
Illustrative embodiments of the present invention provide a process described herein wherein the compound of Formula IV is not isolated before converting the compound of Formula IV to the Lapatinib ditosylate of Formula I.
Illustrative embodiments of the present invention provide a process described herein wherein the converting of the compound of Formula IV to the Lapatinib ditosylate of Formula I comprises: i) treating the compound of Formula IV with about 0.8 to about 1.2 equivalents of p-toluenesulfonic acid (PTSA), thereby forming monotosylate of Formula V:
and ii) treating the compound of Formula V with about 0.8 to about 1.2 equivalents of p-toluenesulfonic acid, thereby forming the Lapatinib ditosylate of Formula I.
Illustrative embodiments of the present invention provide a process described herein wherein the conversion of a compound of Formula IV to Lapatinib ditosylate of Formula I comprises treatment of a compound of Formula IV with about 1.8 to about 2.2 equivalents of p-toluenesulfonic acid.
Illustrative embodiments of the present invention provide a process described herein whereby the process for preparation of Lapatinib ditosylate is a one-pot process in which no intermediates are isolated.
Illustrative embodiments of the present invention provide a process described herein wherein the treating of the compound of Formula II with 2-methanesulphonylethylamine or a salt thereof occurs in the presence of a first base.
Illustrative embodiments of the present invention provide a process described herein wherein the first base is N,N-diisopropylethylamine.
Illustrative embodiments of the present invention provide a process described herein wherein the hydrogenation catalyst is selected from the group consisting of palladium on carbon, platinum on carbon and Raney nickel.
Illustrative embodiments of the present invention provide a process described herein wherein the hydrogenation catalyst is palladium on carbon.
Illustrative embodiments of the present invention provide a process described herein wherein the hydrogenation catalyst is 5% palladium on carbon.
Illustrative embodiments of the present invention provide a process described herein wherein the treating of the compound of Formula II with 2-methanesulphonylethylamine or a salt thereof occurs in the presence of a first solvent selected from the group consisting of alcohols and halogenated hydrocarbons.
Illustrative embodiments of the present invention provide a process described herein wherein the treating of the compound of Formula II with 2-methanesulphonylethylamine or a salt thereof occurs in the presence of a first solvent selected from the group consisting of methanol, dichloromethane and mixtures thereof.
Illustrative embodiments of the present invention provide a composition comprising i) at least one of Lapatinib and Lapatinib ditosylate and ii) at least one of palladium, platinum and Raney nickel.
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.
DETAILED DESCRIPTION
According to illustrative embodiments of the present invention, Lapatinib may be prepared according to Scheme 1 starting from compound of Formula II.
In illustrative embodiments of the present invention, there is provided a process for the preparation of Lapatinib and its ditosylate salt thereof comprising:
i. reductive amination of a compound of Formula II:
by treatment, optionally in the presence of a first base, with 2-methanesulphonylethylamine or its salt, followed by reduction by catalytic hydrogenation in the presence of a suitable hydrogenation catalyst, thereby forming Lapatinib free base of Formula IV:
ii. optionally, conversion of the compound of Formula IV to Lapatinib ditosylate of Formula I:
The first base may be used to liberate the free amine in a case where an acid salt of 2-methanesulphonylethylamine is used. The first base may be any suitable base capable of liberating the free amine. The first base may be inorganic or organic. The first base may be selected from the group consisting of metal hydroxides, carbonates, phosphates, tertiary amines, and aryl amines. The first base may be selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, lithium carbonate, potassium phosphate, sodium phosphate, triethylamine, diisopropylamine, N,N-diisopropylethylamine, N,N-dimethylaniline, N,N-diethylaniline, pyridine and mixtures thereof.
The reductive amination may be conducted in a first solvent. The first solvent may be a suitable protic or aprotic organic solvent. The first solvent may be selected from the group consisting of alcohols (e.g. methanol, ethanol, propanol, isopropanol, butanol), alkyl ethers (e.g. tetrahydrofuran, dioxane, diethyl ether, methyl t-butyl ether, diisopropyl ether, butyl ether), alkyl esters (e.g. ethyl acetate, isopropyl acetate), aromatic and aliphatic hydrocarbons (e.g. toluene, xylenes, hexanes, and heptanes), nitriles (e.g. acetonitrile, propionitrile, butyronitrile, and benzonitrile), N,N-dialkylamides (e.g. N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidinone), halogenated hydrocarbons (e.g. dichloromethane and dichloroethane), and mixtures thereof.
The suitable hydrogenation catalyst may be selected from the group consisting of palladium, platinum, rhodium, ruthenium and nickel. Often, the hydrogenation catalyst is palladium on carbon, platinum on carbon or Raney-nickel. The catalyst loading may be from about 0.1 wt % to about 100 wt % palladium with respect to the weight of a compound of Formula II. The catalyst loading may be from about 0.1% to about 20% with respect to the weight of a compound of Formula II. The suitable hydrogenation catalyst may be finely dispersed solids or adsorbed on an inert support such as carbon or alumina. The suitable hydrogenation catalyst may be 5 wt % palladium on carbon. The hydrogenation may be performed by using hydrogen gas or transfer hydrogenation. It should also be noted that catalyst moistened with water, for instance 50% water wet 5% palladium on carbon, is also suitable.
Optionally, following the reaction of a compound of the Formula II with 2-methanesulphonylethylamine or its salt, an intermediate imine of the Formula III may be isolated prior to catalytic hydrogenation.
The reductive amination of the present invention may cleanly convert the compound of the Formula II to the compound of Formula IV in high yield with few impurities. The reaction occurs under mild conditions and does not require aqueous work-up. This clean conversion allows for preparation of ditosylate of Formula I in high yield and high purity.
The free base of Formula IV may or may not be isolated before conversion to the ditosylate of Formula I. The ditosylate of Formula I may be prepared directly from the free base of Formula IV by treatment with a sufficient quantity of p-toluenesulfonic acid. For example, treatment of the free base of Formula IV with about 1.8 to about 2.2 equivalents of p-toluenesulfonic acid yields the compound of Formula I. Alternatively, the ditosylate may be prepared stepwise, whereby the monotosylate is isolated first, followed by treatment with a second quantity of p-toluenesulfonic acid to yield the ditosylate. For example, treatment of the free base of Formula IV with about 0.8 to about 1.2 equivalents of p-toluenesulfonic acid yields the intermediate monotosylate of Formula V. Treatment of the isolated monotosylate of Formula V with a further about 0.8 to about 1.2 equivalents of p-toluenesulfonic acid yields the ditosylate of Formula I.
In an embodiment, preparation of the compound of Formula I is a one-pot process whereby reductive amination of the compound of Formula II yields a compound of Formula IV, which is treated, without isolation, with p-toluenesulfonic acid to generate the distosylate of Formula I. Conversion of the compound of Formula IV to the compound of Formula I maybe conducted in a second solvent. The second solvent may be a suitable protic or aprotic organic solvent. The second solvent may be selected from the group consisting of alcohols (e.g. methanol, ethanol, propanol, isopropanol, butanol), alkyl ethers (e.g. tetrahydrofuran, dioxane, diethyl ether, methyl t-butyl ether, diisopropyl ether, butyl ether), alkyl ester (e.g. ethyl acetate, isopropyl acetate), ketones (e.g. acetone, methyl ethyl ketone, methyl isobutyl ketone), aromatic and aliphatic hydrocarbons (e.g. toluene, xylenes, hexanes, and heptanes), nitriles (e.g. acetonitrile, propionitrile, butyronitrile, and benzonitrile), N,N-dialkylamides (e.g. N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidinone), sulfoxides and sulfones (e.g. dimethyl sulfoxide and sulfolane), halogenated hydrocarbons (e.g. dichloromethane and dichloroethane), and mixtures thereof. Similar solvents may be employed in each step when the conversion of the compound of Formula IV to the compound of Formula I proceeds stepwise through isolated Lapatinib monotosylate (Formula V).
EXAMPLES
The following examples are illustrative of some of the embodiments of the invention described herein. These examples should not be considered to limit the spirit or scope of the invention in any way.
Example 1
Preparation of N-(3-chloro-4-{[(3-fluorophenyl)methyl]oxy}phenyl)-6-[5-({[2-(methylsulfonyl)ethyl]amino}methyl)-2-furanyl]-4-quinazolinamine, 4-methylbenzenesulfonate
The suspension of 5-[4-((3-chloro-4-((3-fluorobenzyl)oxy)phenyl)amino)-quinazolin-6-yl]-2-furaldehyde (5 g, 10.6 mmoL) and 2-aminoethylmethylsulfone hydrochloride (3 g, 19 mmoL) in methanol (10 mL) and dichloromethane (25 mL) was charged with N,N-diisopropylethylamine (1.6 g, 12.7 mmoL) slowly under constant stirring at room temperature. The reaction mixture was stirred for 2-4 hours until reaction completion. The reaction mixture was charged with 5% Pd—C (750 mg) and stirred under hydrogen atmosphere (after evacuation) for 16-24 hours until reaction completion. The reaction mixture was further charged with methanol (25 mL) and dichloromethane (25 mL) and stirred for 12-16 hours. The obtained mixture was filtered, washed with 1:1 mixture of methanol (20 mL) and dichloromethane (20 mL). The yellow filtrate thus obtained was charged slowly with a solution of p-toluenesulfonic acid monohydrate (2 g, 10.6 mmoL) in methanol (5 mL). The yellow solid which precipitated out was filtered and washed with 1:1 mixture of methanol (20 mL) and dichloromethane (20 mL). The solid obtained was dried under vacuum at 40-45° C. to provide the monotosylate salt of Lapatinib (4.8 g, Yield=60%, HPLC purity>99%).
1 HNMR (400 MHz, DMSO-d 6 ) δ 2.28 (s, 3H), 3.14 (s, 3H), 3.49-3.44 (m, 2H), 3.58-3.61 (m, 2H), 4.42 (s, 2H), 5.28 (s, 2H), 6.85 (d, J=3.4 Hz), 1H), 7.11 (d, J=7.9 Hz, 2H), 7.15-7.20 (m, 2H), 7.25-7.35 (m, 3H), 7.42-7.52 (m, 3H), 7.73 (dd, J=8.9 & 2.1 Hz, 1H), 7.87 (d, J=8.7 Hz, 1H), 8.00 (d, J=2.1 Hz, 1H), 8.24 (dd, J=8.5 Hz, & 1 Hz, 1H), 8.61 (s, 1H), 8.87 (s, 1H), 9.17 (br s, 1H), 10.0 (s, 1H).
Example 2
Preparation of N-(3-chloro-4-{[(3-fluorophenyl)methyl]oxy}phenyl)-6-[5-({[2-(methylsulfonyl)ethyl]amino}methyl)-2-furanyl]-4-quinazolinamine, 4-methylbenzenesulfonate
The suspension of 5-[4-((3-chloro-4-((3-fluorobenzyl)oxy)phenyl)amino)quinazolin-6-yl]-2-furaldehyde (5 g, 10.6 mmoL) and 2-aminoethylmethylsulfone hydrochloride (3 g, 19 mmoL) in methanol (10 mL) and dichloromethane (25 mL) was charged with N,N-diisopropylethylamine (1.6 g, 12.7 mmoL) slowly under constant stirring at room temperature. The reaction mixture was stirred for 2-4 hours until reaction completion. The reaction mixture was charged with 10% Pt—C (500 mg) and stirred under hydrogen atmosphere (after evacuation) for 16-24 hours until reaction completion. The reaction mixture was further charged with methanol (25 mL) and dichloromethane (25 mL) and stirred for 12-16 hours. The obtained mixture was filtered, washed with 1:1 mixture of methanol (20 mL) and dichloromethane (20 mL). The yellow filtrate thus obtained was slowly charged with a solution of p-toluenesulfonic acid monohydrate (2 g, 10.6 mmoL) in methanol (5 mL). The yellow solid which precipitated out was filtered and washed with 1:1 mixture of methanol (20 mL) and dichloromethane (20 mL). The solid obtained was dried under vacuum at 40-45° C. to afford the monotosylate salt of Lapatinib (5 g, Yield=61%, HPLC purity>99%).
Example 3
Preparation of N-(3-chloro-4-{[(3-fluorophenyl)methyl]oxy}phenyl)-6-[5-({[2-(methylsulfonyl)ethyl]amino}methyl)-2-furanyl]-4-quinazolinamine 4-methylbenzenesulfonate
The suspension of 5-[4-((3-chloro-4-((3-fluorobenzyl)oxy)phenyl)amino)quinazolin-6-yl]-2-furaldehyde (5 g, 10.6 mmoL) in methanol (25 mL) and dichloromethane (25 mL) was charged with 2-aminoethylmethylsulfone (1.4 g, 11.2 mmoL) slowly under constant stirring at room temperature. The reaction mixture was stirred for 2-4 hours until reaction completion and then the reaction mixture was charged with 5% Pd—C (500 mg) and stirred under hydrogen atmosphere (after evacuation) for 16-24 hours until reaction completion. The reaction mixture was further charged with methanol (25 mL) and dichloromethane (25 mL) and stirred for 12-16 hours. The obtained mixture was filtered, washed with 1:1 mixture of methanol (20 mL) and dichloromethane (20 mL). The yellow filtrate thus obtained was slowly charged with a solution of p-toluenesulfonic acid monohydrate (2.2 g, 11.2 mmoL) in methanol (5 mL). The yellow solid which precipitated out was filtered and washed with 1:1 mixture of methanol (20 mL) and dichloromethane (20 mL). The solid obtained was dried under vacuum at 40-45° C. to provide the monotosylate salt of Lapatinib (6.5 g, Yield=81%, HPLC purity>99%).
1 HNMR (300 MHz, CDCl 3 ) δ 2.69 (dd, J=5.0, 2.2 Hz, 1H), 2.82 (t, J=4.3 Hz, 1H), 3.20-3.27 (m, 2H), 3.51-3.58 (m, 1H), 3.67-3.71 (m, 2H), 3.96-4.02 (m, 3H), 4.32 (s, 2H), 6.66 (d, J=8.7 Hz, 2H), 7.11 (d, J=8.7 Hz, 2H).
Example 4
Preparation of N-(3-chloro-4-{[(3-fluorophenyl)methyl]oxy}phenyl)-6-[5-({[2-(methylsulfonyl)ethyl]amino}methyl)-2-furanyl]-4-quinazolinamine 4-methylbenzenesulfonate
The suspension of 5-[4-((3-chloro-4-((3-fluorobenzyl)oxy)phenyl)amino)-quinazolin-6-yl]-2-furaldehyde (20 g, 42.2 mmoL) in methanol (100 mL) and dichloromethane (60 mL) was charged with 2-aminoethylmethylsulfone (5.8 g, 46.4 mmoL) slowly under constant stirring at room temperature and then the reaction mixture was stirred for 2-4 hours until reaction completion. The reaction mixture was charged with 5% Pd—C (1 g) and stirred under hydrogen atmosphere (after evacuation) for 16-24 hours until reaction completion. The obtained mixture was filtered, washed with 3:1 mixture of methanol (40 mL) and dichloromethane (20 mL). The filtrate was distilled to low volume whereupon the obtained solution was slowly charged with a solution of p-toluenesulfonic acid monohydrate (8.8 g, 46.4 mmoL) in methanol (20 mL). The yellow solid which precipitated out was filtered and washed with 1:3 mixture of methanol (10 mL) and dichloromethane (30 mL). The solid obtained was dried under vacuum at 40-45° C. to furnish the monotosylate salt of Lapatinib (23.7 g, Yield=75%, HPLC purity>99%).
1 HNMR (300 MHz, CDCl 3 ) δ 2.69 (dd, J=5.0, 2.2 Hz, 1H), 2.82 (t, J=4.3 Hz, 1H), 3.20-3.27 (m, 2H), 3.51-3.58 (m, 1H), 3.67-3.71 (m, 2H), 3.96-4.02 (m, 3H), 4.32 (s, 2H), 6.66 (d, J=8.7 Hz, 2H), 7.11 (d, J=8.7 Hz, 2H).
Example 5
Preparation of N-(3-chloro-4-{[(3-fluorophenyl)methyl]oxy}phenyl)-6-[5-({[2-(methylsulfonyl)ethyl]amino}methyl)-2-furanyl]-4-quinazolinamine 4-methylbenzenesulfonate
The suspension of 5-[4-((3-chloro-4-((3-fluorobenzyl)oxy)phenyl)amino)-quinazolin-6-yl]-2-furaldehyde (10 g, 21.1 mmoL) in dichloromethane (100 mL) was charged with a solution of 2-aminoethylmethylsulfone (5.8 g, 46.4 mmoL) in methanol (50 mL) slowly under constant stirring at room temperature. The reaction mixture was stirred for 2-4 hours until reaction completion and then was charged with 5% Pd—C (0.5 g) and stirred under hydrogen atmosphere at 25 psi pressure for 16-24 hours until reaction completion. The obtained mixture was filtered, washed with a 3:1 mixture of methanol (40 mL) and dichloromethane (20 mL). The filtrate was distilled to low volume, and the obtained solution was slowly charged with solution of p-toluenesulfonic acid monohydrate (4.4 g, 23.2 mmoL) in methanol (10 mL). The yellow solid which precipitated out was filtered and washed with a 1:1 mixture of methanol (20 mL) and dichloromethane (20 mL). The solid obtained was dried under vacuum at 40-45° C. to give the monotosylate salt of Lapatinib (11.4 g, Yield=72%, HPLC purity>99%).
1 HNMR (300 MHz, CDCl 3 ) δ 2.69 (dd, J=5.0, 2.2 Hz, 1H), 2.82 (t, J=4.3 Hz, 1H), 3.20-3.27 (m, 2H), 3.51-3.58 (m, 1H), 3.67-3.71 (m, 2H), 3.96-4.02 (m, 3H), 4.32 (s, 2H), 6.66 (d, J=8.7 Hz, 2H), 7.11 (d, J=8.7 Hz, 2H).
Example 6
Preparation of N-(3-chloro-4-{[(3-fluorophenyl)methyl]oxy}phenyl)-6-[5-({[2-(methylsulfonyl)ethyl]amino}methyl)-2-furanyl]-4-quinazolinamine 4-methylbenzenesulfonate
The suspension of 5-[4-((3-chloro-4-((3-fluorobenzyl)oxy)phenyl)amino)quinazolin-6-yl]-2-furaldehyde (10 g, 21.1 mmoL) in dichloromethane (100 mL) was charged with a solution of 2-aminoethylmethylsulfone (5.8 g, 46.4 mmoL) in methanol (50 mL) slowly under constant stirring at room temperature. The reaction mixture was stirred for 2-4 hours until reaction completion. The reaction mixture was charged with 5% Pd—C (1.5 g) and stirred under hydrogen atmosphere using balloon pressure for 12-16 hours until reaction completion. The obtained mixture was filtered through Celite® pad and rinsed with methanol (30 mL) and dichloromethane (10 mL) mixture. The filtrate was distilled to a low volume and the solution was charged with toluene (50 mL) followed by addition of the solution of p-toluenesulfonic acid monohydrate (4.8 g, 25.3 mmoL) in methanol (25 mL). The yellow solid precipitated out was filtered after 2-8 hours and washed with 1:1 mixture of methanol and toluene (40 mL). The solid obtained was dried under vacuum at 40-45° C. to provide the monotosylate salt of Lapatinib (11.4 g, Yield=93%, HPLC purity>99%).
1 HNMR (300 MHz, CDCl 3 ) δ 2.69 (dd, J=5.0, 2.2 Hz, 1H), 2.82 (t, J=4.3 Hz, 1H), 3.20-3.27 (m, 2H), 3.51-3.58 (m, 1H), 3.67-3.71 (m, 2H), 3.96-4.02 (m, 3H), 4.32 (s, 2H), 6.66 (d, J=8.7 Hz, 2H), 7.11 (d, J=8.7 Hz, 2H).
Example 7
Preparation of N-(3-chloro-4-{[(3-fluorophenyl)methyl]oxy}phenyl)-6-[5-({[2-(methylsulfonyl)ethyl]amino}methyl)-2-furanyl]-4-quinazolinamine bis 4-methylbenzenesulfonate
The suspension of 5-[4-((3-chloro-4-((3-fluorobenzyl)oxy)phenyl)amino)quinazolin-6-yl]-2-furaldehyde (5 g, 10.6 mmoL) in dichloromethane (50 mL) was charged with a solution of 2-aminoethylmethylsulfone (3.2 g, 11.7 mmoL) in methanol (25 mL) slowly under constant stirring at room temperature. The reaction mixture was stirred for 2-4 hours until reaction completion. The reaction mixture was charged with 5% Pd—C (750 mg) and stirred under hydrogen atmosphere using balloon pressure for 12-16 hours until reaction completion. The obtained mixture was filtered through Celite® pad and rinsed with methanol (5 mL) and dichloromethane (15 mL) mixture. The filtrate was distilled to low volume and the solution was charged with dichloromethane (25 mL) followed by addition of the solution of p-toluenesulfonic acid monohydrate (4.4 g, 23.3 mmoL) in methanol (10 mL). The yellow solid which precipitated out was filtered after 2-8 hours and washed with 1:1 mixture of methanol and dichloromethane (20 mL). The solid obtained was dried under vacuum at 40-45° C. to provide Lapatinib (11.4 g, Yield=93%, HPLC purity>99%).
Example 8
Preparation of N-(3-chloro-4-{[(3-fluorophenyl)methyl]oxy}phenyl)-6-[5-({[2-(methylsulfonyl)ethyl]amino}methyl)-2-furanyl]-4-quinazolinamine
The suspension of 5-[4-((3-chloro-4-((3-fluorobenzyl)oxy)phenyl)amino)quinazolin-6-yl]-2-furaldehyde (5 g, 10.6 mmoL) in dichloromethane (50 mL) was charged with a solution of 2-aminoethylmethylsulfone (3.2 g, 11.7 mmoL) in methanol (25 mL) slowly under constant stirring at room temperature. The reaction mixture was stirred for 2-4 hours until reaction completion and then was charged with 5% Pd—C (750 mg) and stirred under a hydrogen atmosphere using balloon pressure for 12-16 hours until reaction completion. The obtained mixture was filtered through Celite® pad and rinsed with methanol (5 mL) and dichloromethane (15 mL) mixture. The filtrate was distilled to low volume and the obtained solution was charged with methanol (25 mL). The reaction mixture was stirred for 2-6 hours and the yellow solid which precipitated out was filtered and washed with methanol (10 mL). The solid obtained was dried under vacuum at 40-45° C. to furnish Lapatinib freebase (5 g, Yield=85%, HPLC purity>99%).
Although various embodiments of the invention are disclosed herein, many adaptations and modifications may be made within the scope of the invention in accordance with the common general knowledge of those skilled in this art. Such modifications include the substitution of known equivalents for any aspect of the invention in order to achieve the same result in substantially the same way. Numeric ranges are inclusive of the numbers defining the range. Furthermore, numeric ranges are provided so that the range of values is recited in addition to the individual values within the recited range being specifically recited in the absence of the range. The word “comprising” is used herein as an open-ended term, substantially equivalent to the phrase “including, but not limited to”, and the word “comprises” has a corresponding meaning. As used herein, the singular forms “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. Thus, for example, reference to “a thing” includes more than one such thing. Citation of references herein is not an admission that such references are prior art to the present invention. Furthermore, material appearing in the background section of the specification is not an admission that such material is prior art to the invention. Any priority document(s) are incorporated herein by reference as if each individual priority document were specifically and individually indicated to be incorporated by reference herein and as though fully set forth herein. The invention includes all embodiments and variations substantially as hereinbefore described and with reference to the examples. | There is provided processes for preparing Lapatinib and pharmaceutically acceptable salts thereof by the reductive amination of the aldehyde of Formula II by treatment with 2-methanesulphonylethylamine followed by catalytic hydrogenation in the presence of a suitable hydrogenation catalyst. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a hydromotor and in particular to a control device of the type having flow restricting means including a proportional directional control valve and a flow control valve with a releasable non-return valve actuated by a spring-loaded cylinder-and-piston unit.
A known control valve which is designed as a speed lowering brake valve is controlled immediately by the pump pressure which is present between the pump and the hydromotor. During fluctuating pump pressure the control piston of the brake valve, which is admitted in accordance with the fluctuations, causes the valve member of the brake valve to be controlled accordingly. Thereby, different pressures are generated between the connection connected with the brake valve and the connection of the directional control valve which is connected with the supply container, whereby at otherwise the same position of the valve member of the directional control valve, different streams of pressure medium flow from the hydromotor to the supply container (the German periodical "Fluid", February, 1979, pages 31-33).
In order to control the hydromotor independently of its load, it is also known to switch a pressure regulator valve between the control side of the brake valve and the hydromotor whose reduced constant pressure acts on the control piston of the brake valve. Thereby, the pressure at the connection point of the brake valve with the proportional directional control valve is kept constant, whereby irrespective of the pressure loss in the lines, the differential pressure between the connections of the directional control valve to the brake valve and to the supply container, is kept constant. Therefore, pressure fluctuations on the pump side or consumer side do not have any effect on the quantity of the return flow. The brake valve acts as a pressure compensator whereby its braking function is not impaired. The use of a pressure control valve is relatively expensive (DE-OS No. 29 11 891).
SUMMARY OF THE INVENTION
It is an object of the present invention to substantially simplify the structural design of the aforementioned device. This object is obtained in accordance with the invention by the provision of a flow control circuit including a flow regulating member connected between one control port of the cylinder-and-piston unit of the flow control valve and the outlet port of the restricting directional control valve leading to the consumer; a throttle connecting the one control port of the cylinder-and-piston unit with the supply container; and a conduit connecting the flow control valve with the other control port at an opposite side of the actuation piston of the cylinder-and-piston unit.
Preferably, the proportional control valve has two pairs of inlet and outlet ports each connected to the consumer via symmetrically arranged flow control valves with associated actuating cylinder-and-piston units each provided with the above described flow control circuit of this invention. The inventive structural design is substantially simpler than the known device which is provided with a pressure control valve, and can therefore be made more economical.
In a further elaboration of this invention, the control piston acts as an adjustment piston for the pressure compensator for opening the valve member, for controlling the flow of the pressure medium for the control of the adjacent control piston, and also as a non-return valve.
The novel features which are considered characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a block diagram of the control device of this invention;
FIGS. 2A and 2B are longitudinal sections through a double valve in the device of this invention; and
FIG. 3 is a segment of a modification of the double valve of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A directional control valve 1 is designed as an electrohydraulic proportional valve and defines, depending on the controllable magnetic current, the throttle face or restricting surface delimited by the control piston and thereby the throughflow quantity of the pressure medium. The directional control valve 1 has a connection A1 which is connected through a line 3 with a connection A3 of a control valve 7a in the form of a releasable non-return valve. The connection B3 of the control valve 7a is connected through a line 8a with a consumer, for example, a double acting hydromotor 2. A connection B1 of directional control valve 1 is connected through a line 4 with a connection A2 of a control valve 7 also in the form of a releasable non-return valve. The connection B2 of the control valve is connected through a line 8 with the hydromotor 2. A connection P on the directional control valve 1 is connected with a pump 5 and another connection T is connected with a supply container 6.
The control valve 7 has a control connection X which is connected through a control line 9 with one side of a flow regulator 12 controlling in the direction to the control connection X. The other side of the regulator is connected through a control line 14 with line 3. A control line 15 in which an adjustable nozzle 16 is provided, is connected to the control line 9 and through a control line 17 with the supply container 6. Nozzle 16 may be replaced by a pressure relief valve which also acts as a throttle.
The control valve 7 has a main valve member 19 and a control piston 20 actuating the same, whereby the same cross sections of the control piston are acted upon through the connections X and A2 leading to control lines 9 or 22 on opposite sides of the piston. A control spring 35 is braced between the control piston 20 and a stationary cylindrical part of the housing of control valve 7 at the side of connection X. The control piston 20 has a piston rod 23 which is guided on the side facing the main valve member 19.
A control line 14a connects control line 9 to line 4. A non-return valve 26a is provided between the connection point of control lines 22 and 14a and another flow regulator 12a corresponding to the flow regulator 12. A non-return valve 26 which opens to the flow regulator 12 is provided in line 14 after the connection point of the control line 14 and 22a. Line 22a is connected with the chamber 44a of cylinder-and-piston unit pertaining to valve 7a.
The control valve 7a with regulator 12a and the non-return valve 26a is structurally the same as the control valve 7 with regulator 12 and non-return valve 26. The lines are indicated with the same numerical references, whereby the reference numerals of the control lines or valves which are associated with the control valve 7a are provided with the additional letter "a".
The control ports X and Xa of control valves 7 or 7a and the control ports of regulators 12 and 12a are connected with each other and with the nozzle 16 by means of control lines 9, 9a and 15 in the manner shown in the drawings.
Assuming that the proportional directional control valve 1 is in a position in which the port P is connected to port A1 and port B1 to port T, then the pressure adjusted on the pressure relief valve 27 is reduced by the throughput resistance through line 3 and the main valve member 19a of control valve 7a which acts as the non-return valve and further through line 8a is applied to a connection on hydromotor 2. On the spring side of the main valve member 19 of the control valve 7, the pump pressure present in the connection B2 of line 8 is either reduced or increased due to the pressure generated by the load of the hydromotor 2, depending on the action direction. The flow regulator 12 permits a constant flow of pressure medium in the direction to the control line 9, independent from the pressure in line 3. This constant flow of pressure medium generates on throttle or nozzle 16 a uniform impact pressure which acts through the control connection X on control piston 20. Thereby, the pressure of connection A2 of the control valve 7 remains constant. This pressure corresponds to the pressure in control connection X in addition to the pressure generated by the force of control spring 35 and less the pressure generated by pressure spring 49.
The pressure differential between the connections B1 and T of the proportional directional control valve 1 is kept constant with the assistance of the control valve 7, so that a uniform quantity flows through the proportional directional control valve 1, independent from the pressure in line 8. The superfluous pressure between the connections B2 and A2 is removed by the main valve member 19.
The other control valve 7a has the same effect as the control valve 7. When the proportional directional control valve 1 is switched in the median position as shown in the drawing, the connections A1 and B1 are immediately connected with the supply container 6 and the control connections X and Xa through the nozzle 16 with the supply container. The pressure in these connections corresponds to the pressure in the supply container and the pressure springs 49 and 49a of control valves 7 and 7a close the main valve members 19 and 19a free from pressure medium against the pressure generated by the load in hydromotor 2. As will be explained later, in the other two switch positions of the proportional directional control valve 1, the main valve members 19 and 19a also close free of pressure medium the pressure generated by the load even in the case when the pump pressure due to pipe breakage or power failure collapses to the pressure in supply container 6. The advantage of the control valves 7 and 7a connected in the aforedescribed manner is in the fact that they act as pressure compensator for pressures generated by loads, independent from the direction of the given load. Thereby, an advancing of this load is effectively eliminated. In addition, the main valve members 19 and 19a and their pre-control members 51 or 51a (FIG. 2) which are designed as seat elements permit a pressure medium free closing off during failing pump pressure and thereby prevent a lowering of the load.
For example, if the hydromotor 2 is designed as a differential cylinder with a face ratio of 1:2 and if the outer load acts on the annular face of the piston adjoining the piston rod, a pressure would be active during a discharge control in this cylinder space which would amount to a sum of the twofold pump pressure and the pressure generated by the load. For eliminating such a high cylinder load the throttling surfaces of the control piston of the proportional directional control valve 1 in the passages from ports A1 and B1 to the port T are designed larger with respect to the throttling surfaces in the passages from port P to ports A1 or B1. Thereby, the load independent discharge control during a negative load could be changed in a supply control and the pressure on the piston rod side of the differential cylinder is substantially limited to the pressure generated by the load. Thereby, the control valve 7 assumes the function of a braking valve. As described in the following, the use of two releasable control valves 7 and 7a results in a simplification in the structural design since the flow regulator 12 of control valve 7a supplies the constant flow of pressure medium for generating the constant impact pressure on the nozzle 16 for the control connection X of the control valve 7. The same is true in a reversed manner for the flow regulator 12a.
In the structural design of the double valve 7a and 7 shown in FIGS. 2A and 2B, a housing 18 has a center bore 31 into which bushings 32 and 32a are inserted from the two end sides thereof. On the opposite faces the bushings are provided with end pieces 33 and 33a. The two end pieces 33, 33a engage with each other and are disposed in the center of the center bore 31. The bushings 32, 32a are retained by means of a jacket-like hollow screws 34 and 34a respectively which is screwed into the housing. The hollow screw 34 engages the bushing 32 and urges its shoulder 30 onto a counter shoulder in housing 18, whereas a corresponding shoulder 30a of bushing 32a is spaced apart a small distance from the associated counter shoulder in housing 18.
In the range of its end piece 33, the bushing 32 receives the control piston 20. A control spring 35 is braced between the end piece 33 and the control piston 20. The control piston 20 is designed like a sleeve and supports in its jacket a calibrated nozzle 36 which extends therethrough. In the position of the control piston 20 shown in the drawing, an annular groove 37 is provided in bushing 32 in the area of the calibrated nozzle 36. A radially extending control bore 38 is provided in bushing 32 between the annular groove 37 and the end piece 33 which opens into an annular groove 39 provided on the outer side of bushing 32. In the position of the control piston 20 shown in the drawing, the control bore 38 is open. The edge of the control piston 20 adjacent to this control bore 38 acts as a control edge 40.
A locking screw 42 is screwed into the hollow piston rod 23 of the control piston 20. Furthermore, radial bores 43 are provided in the area of the control piston 20 which connect the inner space of piston rod 23 with the chamber 44 encompassing the piston rod. The piston rod 23 supports at its end removed from control piston 20 an axially protruding pin 45, parallel to which bores 82 are provided with respect to the front side of the piston rod 23. The piston rod 23 is guided in a transverse wall 41 of bushing 32 which separates the chamber 44 from the chamber 46. The chamber 44 is connected with an annular groove 48 on the outer circumference of bushing 32 by means of a radial bore 47 provided in bushing 32. A throttle screw with a throttle location can be screwed into the radial bore 47.
The sleeve-like main valve member 19 is displaceably mounted in the bushing 32 away from the end piece 33. A valve spring 49 braced between the bottom of the hollow screw 34 and the main valve member 19 holds the main valve member 19 on a frustoconical valve seat 50 of bushing 32. A pre-control member 51 is axially and displaceably mounted in the main valve member 19 which is provided with a frustoconical valve seat 52 and a slide-like valve part 53. The frustoconical valve part 52 controls a stepped valve bore 54 provided on the bottom of the main valve member 19 and the valve part 53 controls radial transverse bores 79 in the jacket of the main valve member 19 which discharge in annular grooves 55 and 56 on the outside and the inside of the main valve member 19.
The pre-control member 51 has a center bore 57 which extends to the valve part 52, whereby a throttle screw can be screwed into the center bore with a throttle location on the side facing away from the valve part 52. The center bore 57 is connected through a transverse bore 58 with a chamber 59 which is limited from the bottom of the main valve member 19 and the valve part 52 as well as the side of the pre-control member 51 facing the valve part 52. The valve part 53 has an annular groove 60 which, in the shown closed position of the pre-control member 51, is disposed on the side of the annular groove 56 facing away from the valve part 52. The annular groove 60 is connected with bores 61 which are present in the pre-control member 51 disposed parallel to center bore 57 which discharge into chamber 59. A pre-control spring 64 is braced between the pre-control member 51 and a perforated disk 63 retained by a clamp ring 62. The bias of this spring is so large that the pre-control valve 52, 52a maintains its closed position when the main valve member 19, 19a operates like a non-return valve.
An annular groove 80 is disposed opposite annular groove 48 in housing 18 which is connected through a hollow chamber 65 and a bore 66 with the connection location A2. The chamber 46 is connected with the annular groove 48 by means of an oblique bore 67. Radial bores 68 are provided in the area of the annular groove 55 disposed in the main valve member 19 which discharge in an annular groove 69 in housing 18 in the shown position of the main valve 19. The annular groove 69 is connected through a hollow chamber 70 and a bore 71 with the connecting location B2.
A packing ring 72 is disposed in an annular groove in the area of annular groove 37 on the outside of bushing 32. A second packing ring 73 is disposed between the annular groove 48 and the radial bores 68. The packing rings 72 and 73 seal the slot between the bushing 32 and housing 18. Adjacent the radial bores 68, on the side facing away from the end piece 33, radial bores 74 with a smaller diameter are provided which do not open into the annular groove 75 in bushing 32 as is the case with the radial bores 68, but open into the radial groove 69 in housing 18. The hollow screw 34 is in alignment with a sealing edge 83 on the bushing 32. The slot between the hollow screw 34 and the housing 18 is sealed by a packing ring 76. The end piece 33 has the same outer diameter as the bottom of the annular groove 39 on the end of bushing 32 facing end piece 33.
The aforedescribed parts are located in the right half of housing 18. The parts located in the left side of housing 18 correspond essentially to the aforedescribed parts and are indicated with the same reference numerals as the parts illustrated on the right side of the drawing, whereby the small letter "a" is added.
In its center, housing 18 has a connection port C to which line 17 is connected. A bore 77 is provided in the connecting location into which an exchangeable throttle screw 78 is screwed, defining the nozzle 16.
When the connecting location A3 is connected through directional control valve 1 with pump 5, the pressure medium flows into bore 66a, the hollow chamber 65a, the annular groove 48a, the oblique bore 67a and the chamber 46a. The main valve member 19a opens under the pressure of the pressure medium whereby pressure medium flows through the radial bores 68a, annular grooves 75a and 69a, hollow chamber 70a and the bore 71a to the connecting location B3 and from there through line 8a to hydromotor 2. The open position of the main valve member 19a is limited as soon as the limiting edge of annular groove 55a facing the valve seat 50a passes by the radial bore 74a in bushing 32a and thereby closes the chamber provided with the springs 49a and 64a. Simultaneously, pressure medium flows into chamber 44a from the annular groove 48a through radial bore 47a. A connection between the chambers 46 a and 44a is also established through the hollow piston rod 23. The control piston 20a is under the pressure of the pressure medium fed from pump 5 on its piston rod side. In the illustrated position of control piston 20a, the chamber enclosing the control spring 35 is closed with respect to chamber 44a and is connected through control bore 38a, annular groove 39a, nozzle 16 and bore 77 through line 17 with supply container 6. The control piston 20a together with piston rod 30 is pushed to the right by means of the pressure prevailing in chambers 44a, 46a against the control spring 35, whereby the annular groove 37a comes into connection with chamber 44a and pressure medium flows through the calibrated nozzle 36a into the chamber provided with the control spring 35a. During the movement of the control piston 20a in the direction of end piece 33a, the control edge 40a of control piston 20a passes by the adjacent control bore 38a, whereby its orifice cross section is reduced. Thereby, a pressure builds up in the chamber having the control spring 35a, until the control piston 20a comes into a rest position due to the balance of the forces acting thereupon. The pressure in the chambers 44a, 46a acts on the left side of the control piston 20a connected with the piston rod 23a, and the pressure in the chamber which encloses the control spring 35a acts on the right side of the piston 20a and the force of the control spring 35a acts toward the right side of the drawing. Therefore, a pressure differential prevails between chamber 44a and the chamber with the control spring 35a, which corresponds to the force of control spring 35a. In the balanced position of the control piston 20 a constant quantity of liquid flows through the calibrated nozzle 36a, the control bore 38a and the nozzle 16 (throttle) to supply container 6, depending on the cross section of calibrated nozzle 36a and on the pressure corresponding to the force of control spring 35a.
The pressure building up between the two interconnected annular grooves 39 and 39a is defined by the cross section of throttle 16. The pressure in the annular grooves 39a, 39 propagates through the control bore 38 into the chamber receiving the control spring 35 and acts in the same direction as this control spring against the control piston 20 mounted in the right half of housing 20. This pressure remains constant as long as the control piston 20a is in its balanced position. Due to the pressure on the side of the end piece 33 exerted on the control piston 20 and the force resulting therefrom, the valve seat 52 of pre-control member 51 is at first lifted from its seat in main valve member 19 and the valve part 53, which is designed as a slide, closes the connection from the port B2 to the chamber provided with the valve spring 49. The pressure generated by the load acting on hydromotor 2 in the chamber with the valve spring 49 drops through the center bore 57, the transverse bore 58, the chamber 59, the stepped valve bore 54 to the pressure in chamber 46 or 44. Now the main valve member 19 is pressure balanced and the control piston 20 engages with its piston rod 23 onto the main valve member 19 and lifts it from the frustoconical valve seat 50 of bushing 32. The main valve member 19 is now displaced from control piston 20 against the force of valve spring 49 to such an extent until the quantity of pressure medium flowing through the connecting port B2, bore 71, hollow chamber 70, the two annular grooves 69 and 75, radial bores 68, chamber 46, the oblique bore 67, the two annular grooves 48 and 80, hollow chamber 65, bore 66, the connecting port A2, has built up a defined pressure on the control edge of the proportional directional control valve 1. This pressure, which acts through the radial bore 47 in chamber 44 and onto the annular face of the control piston 20, as well as through the transverse bores 43 and the bores 82 which are disposed parallel to the pin 45 onto the face of piston rod 23, opposes the pressure prevailing in the chamber receiving the control spring together with the force of the valve spring 49, and the force of control spring 35.
A balance of forces prevails on control piston 20 when the forces of the control spring 35 and the pressure acting in the chamber provided with the control spring 35 are the same on the one side as the force exerted by the pressure in chamber 44 on control piston 20 and the piston rod 23, in addition to the force exerted by the valve spring 49, on the other side. Since the force exerted on control piston 20 from the left is constant, a constant pressure prevails in chamber 44 and thereby in connection port A2. When the load acting on the hydromotor 2 changes, the predetermined constant pressure in connection port A2 is automatically adjusted by the corresponding control movements of the main valve member 19.
The mode of operation of the two sides of the double valve 7, 7a is reversed when the other side of the hydromotor 2 is connected with the pressure side of pump 5 or with the supply container 6, respectively.
The constant control pressure required for the load independent braking movement is not obtained by an additional control device in the aforedescribed double valve, but by the control pistons 20a or 20 on the side of the double valve whose main valve member 19a or 19 controls the pressure medium supply to hydromotor 2. This feature results in a compact construction which has the additional advantage due to the fact that as shown in the illustrated embodiment of the double valve, the chambers receiving the two control springs 35, 35a are facing each other and are connected through the annular grooves 39, 39a with the common nozzle 16. Since the two control chambers with the two control springs 35 and 35a are under the same pressure, no special reverse switching member between these two control chambers is required. Therefore, the control piston 20, 20a has also the additional function of a flow regulator, whereby the two control valves 7 or 7a in the common housing 18, cooperate together.
In FIG. 3, instead of a nozzle 16 a pressure relief valve 83 is provided in bore 77 which opens in the direction to channel 81 leading to control line 17. From the outside, a retaining screw 84 is screwed into bore 77. The end of bore 77 facing away from the retaining screw 84 is provided with a practically non-throttling orifice which is connected with the annular groove 39. The side of the orifice facing away from the annular groove 39 is designed as a valve seat which coacts with a cone-shaped valve member 85. A valve spring 86 is braced between the retaining screw 84 and the valve member 85.
The term "throttling means" denotes both the nozzle 16, as well as the pressure limiting valve 83. | A device for controlling a consumer, in particular a hydromotor includes a restrictor, preferably an electrohydraulic proportional directional control valve, and a control valve operating on the basis of a releasable non-return valve. The control valve is provided with an actuating cylinder-and-piston unit having control ports and a biasing spring for the piston. The control valve also has a connecting port which is connected with a connecting port of the restrictor. In order to substantially simplify the structural design of the device, a flow regulator is installed between the control port of the control valve and the connecting port of the restrictor which is connected with the consumer. The control sides of the flow regulator and the control valve are connected through a throttle with a supply container. The space of the cylinder-and-piston unit adjoining the control side of the control piston is connected with another connecting port of the control valve and with the restrictor. | 5 |
TECHNICAL FIELD
The present invention relates to a stencil printing device, and in particular to a stencil printing device for carrying out stencil printing by using a printing ink consisting of a mixture of a first liquid and a second liquid.
BACKGROUND OF THE INVENTION
The printing ink used in stencil printing devices in most cases consists of W/O type emulsion ink having an appropriate consistency. Such a printing ink is typically produced in a factory by mixing and emulsifying oil and water containing dye (pigment) by using a mixer, and is commercially available in ink bottles. Since the effective part of the printing ink is limited to the oil component of such an emulsified ink, an bottle of printing ink tends to be consumed by printing a limited number of prints, and it is necessary to replace the ink bottle more often than desired.
It is known that emulsion printing ink tends to undergo some changes in its property and to separate into oil and water in time. Printing ink which has separated into oil and water and is thus made uneven in its properties loses its original consistency (viscosity), and may lose its suitability as printing ink for stencil printing. Therefore, there is a certain service life in the emulsion printing ink packaged in an ink container.
Furthermore, most printing inks for stencil printing such as emulsion inks and oil inks are subjected to changes in their consistency depending on the surrounding temperature, and it is necessary to adjust the contents of the printing ink depending on the season of the year for keeping the consistency or viscosity at an appropriate level irrespective of the surrounding temperature.
BRIEF SUMMARY OF THE INVENTION
In view of such problems of the prior art, a primary object of the present invention is to provide a stencil printing device which allows relatively large number of prints to be made with each bottle of printing ink so that the frequency of replacing the ink bottle may be reduced.
A second object of the present invention is to provide a stencil printing device which allows stable stencil printing to be carried out by receiving printing ink having prescribed consistency and other desirable properties irrespective of the age of the printing ink or the surrounding temperature.
A third object of the present invention is to provide a stencil printing device which allows uniform print results to be achieved at all times without requiring any human intervention.
These and other objects of the present invention can be accomplished by providing a stencil printing device for carrying out stencil printing by using a printing ink consisting of a mixture of a first liquid and a second liquid, comprising: a first liquid storage container for storing the first liquid; a second liquid storage container for storing the second liquid; a mixing unit for receiving the first liquid from the first liquid storage container and the second liquid from the second liquid storage container, and producing printing ink by mixing the two liquids; printing ink supply passage means for conducting the printing ink produced by the mixing unit to an ink squeegee unit of a printing drum for stencil printing; ink amount detecting means for detecting the amount of the printing ink in the ink squeegee unit; and ink supply control means for controlling the amount of the printing ink that is supplied from the mixing unit to the ink squeegee unit according to the amount of printing ink detected by the ink amount detecting means.
According to such a structure, the mixing unit receives the first liquid from the first liquid storage container, and the second liquid from the second liquid storage container, and produces the printing ink by mixing the two liquids. The printing ink is then supplied to the ink squeegee unit of the printing drum for stencil printing. The first liquid storage container typically accommodating an original ink liquid based on an oily substance is disposed inside the cylindrical printing drum for stencil printing while the second liquid typically consists of a water phase component liquid which is adapted to form an emulsified printing ink by being mixed with the original ink liquid. Preferably, the mixing unit is placed in a printing device main body, and the second liquid storage container is located at a position higher than the mixing unit, and communicated with the mixing unit via a control valve controlled by the mixing control means so that a prescribed amount of the water phase component liquid may be supplied to the mixing unit under the action of the gravity.
Thus, a relatively large number of prints can be made from each bottle of printing ink because the water phase component liquid can be refurbished as required. Thus, the frequency of replacing the ink bottle, and hence the possibility of smearing the cloths of the user and the room can be reduced.
The stencil printing device may further comprise recirculation supply passage means for recycling the mixture produced by the mixing unit back to the mixing unit, and the mixing unit may consist of a mixing pump unit which also serves as an ink supply pump for metering the mixture to the ink squeegee unit. Thus, a highly efficient mixing unit can be achieved without increasing the cost or the size.
To the end of attaining a desired consistency and other desired properties, the stencil printing device may further comprise consistency detecting means for detecting a consistency of the printing ink produced by the mixing unit; and mixing control means for controlling the ratio of supply of the first and second liquids according to the consistency of the printing ink detected by the consistency detecting means. The ratio of the first and second liquids supplied to the mixing unit is controlled according to the consistency of the printing ink, and the required amount of printing ink having a prescribed consistency can be prepared immediately before the use and supplied to the ink squeegee unit irrespective of the surrounding temperature. The consistency of the printing ink can be conveniently detected by measuring a load of drive means actuating the mixing unit.
BRIEF DESCRIPTION OF THE DRAWINGS
Now the present invention is described in the following with reference to the appended drawings, in which:
FIG. 1 is a schematic overall structural view of an essential part of an embodiment of the stencil printing device according to the present invention; and
FIG. 2 is a sectional view taken along line II--II of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 and 2 illustrate an embodiment of the stencil printing device according to the present invention. In these drawings, numeral 1 generally denotes a printing drum for stencil printing. The printing drum 1 comprises a fixed hollow cylindrical member 3, and a printing drum main body 9 which is coaxially disposed around the fixed cylindrical member 3 and rotatably supported by the fixed cylindrical member 3 via a pair of roller bearings 5 and 7 at its two axial ends, and is thus supported at two axial ends by the fixed cylindrical member 3 which is in turn detachable from a fixed frame 11 forming a part of a printing device main body. In other words, the hollow cylindrical member 3 is fixedly secured to the fixed frame 11, and rotatably supports the cylindrical printing drum main body 9 much like a hollow shaft.
The printing drum main body 9 consists of a thin-shell cylindrical member 13a, and a pair of annular end support rings 13b engaging the two axial ends of the cylindrical member 13a, and are rotatably supported at both its axial ends by the roller bearings 5 and 7 via the end support rings 13b.
The printing drum main body 9 is provided with an master plate sheet clamp 17 on its platform portion 15 fixedly secured on its outer circumferential surface so that a stencil master plate sheet may be mounted on the outer circumferential surface of the printing drum main body 9 with a leading edge of the stencil master plate sheet clamped by the master plate sheet clamp 17. The outer circumferential surface of the cylindrical member 13a, except for the region of the master plate sheet clamp 17 and its vicinity, is formed as an ink permeable portions by forming it into a fine porous structure by electroforming or the like.
A ring gear 19 is fixedly mounted on one of the end support rings 13b in coaxial relationship to the cylindrical member 13a, and a drive gear 21 meshes with the ring gear 19. The drive gear 21 is actuated in clockwise direction as seen in FIG. 2 by a printing drum drive motor not shown in the drawings which is fixedly arranged in the stencil printing device main body, and the printing drum 9 is rotated in counter clockwise direction around its central axial line.
A relatively narrow annular gap 25 is defined between the outer surface of the hollow cylindrical member 3 and the printing drum main body 9, and a cylindrical chamber 27 having two open axial ends is defined inside the hollow cylindrical member 3. The cylindrical chamber 27 is separated from the annular gap 25 by the hollow cylindrical member 3.
The cylindrical chamber 27 consists of a relatively large chamber having a large diameter determined by the diameter of the hollow cylindrical member 3, and this cylindrical chamber 27 is laterally separated into two chambers by an internal partition wall 31 as seen in FIG. 1, the right chamber being defined as an original ink liquid storage container portion 33. The original ink storage container 33 receives a piston member 35 in an axially slidable manner, thereby defining an original ink liquid storage container chamber 37 between the piston member 35 and the internal partition wall 31. The original ink liquid storage container chamber 37 accommodates therein an original ink liquid, or an oil phase component of emulsion ink for stencil printing. The original ink liquid may contain a dye, an emulsifier and so on in its oily medium.
The internal partition wall 31 is provided with an original ink liquid outlet 39, onto which a suction port 43 of an original ink liquid delivery pump 41 is fitted in a detachable manner.
A squeegee blade mounting portion 45 is provided on a lower part of the outer circumferential part of the hollow cylindrical member 3, and a squeegee blade 47 is mounted on the squeegee blade mounting portion 45. The squeegee blade 47 is located in the annular gap 25 which is small enough to barely accommodate only the squeegee blade 47.
The squeegee blade 47 is made of rubber or rubber-like material, and engages the inner circumferential surface of the cylindrical member 13a of the printing drum main body 9 at a prescribed squeegee angle and a prescribed squeegee pressure.
An ink supply pipe 49 is fixedly arranged in the cylindrical chamber 27. The ink supply pipe 49 passes through the wall of the cylindrical member 3, and extends into the annular gap 25. The terminal end of the ink supply pipe 49 located in the annular gap 25 defines an ink outlet 51, and the other end of the ink supply pipe 49 fits into an ink supply port 53 fixedly arranged in the stencil printing device main body.
The ink outlet 51 of the ink supply pipe 49 is fixedly placed so as to trail the squeegee blade 47 by a small distance, and feeds printing ink to a region trailing the point of contact between the cylindrical member 13a and the squeegee blade 47. The printing ink in this region forms a small ink reservoir P.
The hollow cylindrical member 3 is provided with an ink amount sensor 57 for detecting the amount of the printing ink in the ink reservoir P with an ink amount detecting needle according to an electrostatic principle.
The stencil printing device main body includes the original ink liquid delivery pump 41, the electric motor 59 for actuating the original ink liquid delivery pump 41, the mixing unit 63 actuated by the motor 61, and a water tank 65 all in a fixed arrangement. The water phase component for the emulsion ink for stencil printing stored in the water tank 65 may contain a surface reactant and a moisturizing agent.
The mixing unit 63 may consist of an emulsifying unit of a type incorporating a pump of a gear, screw or other type, and includes a suction port 67 which is directly connected to a mixing reservoir 69 in liquid communication, and an ejection port 71 connected to one of ports 73a of a solenoid flow passage switching valve 73 in liquid communication.
The mixing reservoir 69 consists of an ink buffer of a small capacity corresponding to the amount of printing ink for each cycle, and is connected to an ejection port 77 of the original ink liquid delivery pump 41 via the original ink liquid supply pump 75 to be metered by the original ink liquid delivery pump 41.
The mixing reservoir 69 is also connected to a water supply control valve 81 via a water supply pipe 79, and the water supply control valve 81 is in turn connected to an outlet port 83 of the water tank 65. Thus, by virtue of this communication structure, the water phase component liquid from the water tank 65 is metered to the mixing reservoir 69 by the water supply control valve 81 under the action of the gravity.
The water supply control valve 81 may be electromagnetically actuated, and may consist of either a flow control valve which is capable of variably changing its opening area or an on-off valve which is capable of variably changing the opening time period.
One of the two remaining ports 73b of the solenoid flow passage switching valve 73 is directly connected to the ink supply port 53 via an ink supply pipe 85, and the remaining port 73c is connected to the mixing reservoir 69 via the recirculation pipe 87.
The ink amount sensor 57 is connected to a control unit 89 via a signal line, and supplies an ink amount detection signal to the control unit 89. The control unit 89 comprises a microcomputer embodying ink production and supply control means, and includes, as an internal circuit, current detecting circuit 91 for detecting the electric current supplied to the motor 61 as an indication of the load of the motor 61. The control unit 61 controls the motors 59 and 61 as well as the operation of the solenoid flow passage switching valve 73 and the water supply control valve 81 in dependence on the amount of printing ink detected by the ink amount sensor 57 and the electric current detected by the current detecting circuit 91 according to a prescribed program, and controls the amounts of the original ink liquid and the water phase component, their mixing ratio, and the amount of the printing ink supplied to the ink squeegee unit or the ink reservoir P so that an emulsion ink of a desired consistency may be obtained.
A press roller 93 is provided under the printing drum 1 for stencil printing, and printing paper is fed from left to right as seen in FIG. 2 between the printing drum 1 and the press roller 93 in synchronism with the rotation of the printing drum 1 by a known paper feeding unit not shown in the drawings. A desired stencil printing is thus carried out by pressing the printing paper against the stencil master plate sheet mounted on the printing drum 1 with the press roller 93.
According to such a structure, before starting the printing, first of all, the motor 59 is activated, and the original ink liquid in the original ink liquid storage chamber 37 is metered to the mixing reservoir 69 by the original ink liquid delivery pump 41 via the original ink liquid supply pipe 75 while the water phase component liquid from the water tank is likewise metered to the mixing reservoir 69 by the water supply control valve 81 via the water supply pipe 79. The ratio of the original ink liquid and the water phase component liquid is quantitatively controlled by the time duration of the operation of the motor 59 and the opening area or the opening time period of the water supply control valve 81. This supply ratio may consist of an initially predetermined standard supply ratio.
Once the original ink liquid and the water phase component liquid are supplied to the mixing reservoir 69, the motor 61 starts actuating the mixing unit 63 which draws the original ink liquid and the water phase component liquid from the mixing reservoir 69, and mixes and emulsifies them before finally ejecting it to the solenoid flow passage switching valve 73.
At this time point, because the solenoid flow passage switching valve 73 communicates the port 73a to the port 73c, the mixture expelled from the mixing unit 63 is returned to the mixing reservoir 69 via the recirculation pipe 87, and is resupplied to the mixing unit 63. The mixing unit 63 thus produces the emulsion ink (printing ink) by mixing and recirculating the original ink liquid and the water phase component liquid.
The mixing operation of the mixing unit 69 is stopped when the electric current detected by the electric current detecting circuit 91 or the load of the motor 61 actuating the mixing unit has reached the prescribed level indicative of the attainment of a prescribed consistency by the mixture (emulsion ink) in the mixing unit 63.
If the printing ink fails to attain the prescribed level of consistency after the mixing operation has been continued for more than a prescribed time period, the original ink liquid or the water phase component liquid is added to the mixing reservoir so that the supply ratio of the original ink liquid and the water phase component liquid may be appropriately corrected.
When the amount of the printing ink in the ink reservoir P detected by the ink amount sensor 57 falls below a prescribed limit, the port 73a of the solenoid flow passage switching valve 73 is communicated with the port 73b while the motor 61 starts actuating the mixing unit 63. As a result, the mixing unit 63 operates as a printing ink supplying pump, and the emulsion ink prepared in the mixing reservoir 69 to a prescribed consistency is supplied to the ink reservoir P via the ink supply pipe 49.
When the amount of the printing ink in the ink reservoir P as detected by the ink amount sensor 57 exceeds a prescribed level as a result of such a process of supplying printing ink, the printing ink is stopped from being supplied any further, and the original ink liquid and the water phase component liquid are supplied to the mixing reservoir 69 at the standard supply ratio and by an amount corresponding to the amount of the printing ink consumed during the above mentioned process of supplying printing ink or the reduction in the amount of the printing ink in the mixing reservoir 69. The mixing unit 63 then produces the emulsion ink having the prescribed consistency by recirculation. The refurbishing of the emulsion ink in the mixing reservoir 69 is carried out in this manner.
If the emulsion ink of the prescribed consistency cannot be obtained even when the mixture is mixed for more than the prescribed time period, the original ink liquid or the water phase component liquid is added to the mixing reservoir 69 to adjust the supply ratio of the original ink liquid and the water phase component liquid.
If the emulsion ink in the mixing reservoir 69 is not consumed for more than a prescribed time period after completion of the mixing process, the mixing unit 63 is actuated to determine the consistency of the emulsion ink according to the actuation load, and upon detection of a substantial drop in the consistency of the emulsion ink, the mixing unit 63 is operated until the desired consistency is attained.
Thus, emulsion ink of a suitable consistency can be produced on the on-demand basis according to the consumption of the printing ink in the ink squeegee unit, and suitable printing ink having an appropriate consistency can be supplied to the ink reservoir P at all times.
If there is any emulsion ink left in the ink reservoir P upon completion of a printing process, the mixing unit 63 may be actuated in reverse direction by the motor 61 so that the excess emulsion ink in the ink reservoir P may be drawn by the mixing unit 63 via the ink supply pipe 49 to return it to the mixing reservoir 69, and this emulsion ink may be mixed by the mixing unit 63 until the desired consistency is attained when resuming the operation of the stencil printing device.
Because the original ink liquid is stored in the original ink liquid storage chamber 37 instead of the emulsion ink, the possible number of prints for a given amount of printing ink can be significantly increased as compared to the case of storing the emulsion ink.
The original ink liquid storage chamber 37 was provided inside the printing drum in the above described embodiment while the water tank 65 was provided in the printing device main body, but the present invention is not limited by this embodiment, and the original ink liquid storage chamber 37 may also be located in the printing device main body while the water tank is provided inside the printing drum. Also, the original ink liquid storage chamber 37 and the water tank may be both located in the printing device main body or the printing drum. The original ink liquid storage chamber 37 and the water tank 65, when they are to be installed inside the printing drum, may consist of refill or throw-away removable bottles.
In the above described embodiment, the mixing operation of the mixing unit 63 was controlled according to the amount of the printing ink in the ink squeegee unit as detected by the ink amount sensor 57, but may also be controlled according to the amount of the printing ink in the mixing reservoir 69. In this case, the ink amount sensor 95 may be provided in the mixing reservoir 69.
Alternatively, the stencil printing device may be constructed in such a manner that the original ink liquid storage chamber 37 accommodates original emulsion ink having a relatively low water content, and the water phase component liquid from the water tank 65 is added to it to produce and supply emulsion ink having the prescribed consistency. It is also possible to add an oil component to oil ink to adjust its consistency, and the stencil printing device may also be constructed so as to use two-liquid reaction type printing ink. The mixing unit may be of a suitable type depending on the kind of the printing ink that is to be mixed and produced in the mixing unit.
As can be understood from the above description, according to the stencil printing device of the present invention, because the printing ink is mixed and produced in the mixing unit provided in the stencil printing device, and supplied to the ink squeegee unit, it is possible to produce a required amount of printing ink in the mixing unit according to the consumption of the printing ink in the ink squeegee unit immediately before use, and the operation of the mixing unit and the supply ratio of the first liquid and the second liquid to the mixing unit can be controlled according to the consistency of the printing ink. Thus, because the required amount of printing ink having a prescribed consistency can be produced immediately before use without regard to the surrounding temperature, and supplied to the ink squeegee unit at all times, a stable stencil printing can be always accomplished by using printing ink having a prescribed consistency and other prescribed properties.
In the case of the emulsion ink, because the water phase component liquid is added to the original ink liquid by the ratio of approximately 3 to 7 to prepare the emulsion ink, the amount of the emulsion ink made available from one bottle of original ink liquid is substantially increased by addition of the water phase component liquid, and a large number of prints can be made simply by adding a required amount of the water phase component liquid. Thus, the frequency of handling the printing ink by the user or the service personnel can be reduced, and the possibility of smearing the clothing and the room can be reduced.
Although the present invention has been described in terms of a specific embodiment thereof, it is possible to modify and alter details thereof without departing from the spirit of the present invention. | The stencil printing device of the present invention comprises a mixing unit for receiving the first liquid from the first liquid storage container and the second liquid from the second liquid storage container, and producing printing ink by mixing the two liquids, a printing ink supply passage for conducting the printing ink produced by the mixing unit to an ink squeegee unit of a printing drum, ink amount sensor for detecting the amount of the printing ink in the ink squeegee unit, and ink supply control unit for controlling the amount of the printing ink that is supplied from the mixing unit to the ink squeegee unit according to the amount of printing ink detected by the ink amount sensor. Thus, a relatively large number of prints can be made with each bottle of printing ink so that the frequency of replacing the ink bottle may be reduced. Additionally, stable stencil printing can be carried out by receiving printing ink having prescribed consistency and other desirable properties irrespective of the age of the printing ink or the surrounding temperature without requiring any human intervention. | 1 |
[0001] The present application is a 37 C.F.R. §1.53(b) continuation of U.S. patent application Ser. No. 12/985,389 filed on Jan. 6, 2011, which is a 37 C.F.R. §1.53(b) continuation of U.S. patent application Ser. No. 12/639,872 filed on Dec. 16, 2009, now U.S. Pat. No. 7,930,910 B2, which is a 37 C.F.R. §1.53(b) continuation of U.S. patent application Ser. No. 12/267,457 filed Nov. 7, 2008, currently pending, which is a 37 C.F.R. §1.53(b) continuation of U.S. patent application Ser. No. 10/461,451 filed Jun. 16, 2003, now U.S. Pat. No. 7,533,548 B2, which claims priority to Korean Patent Application No. 85521/2002, filed Dec. 27, 2002, the entire contents of which are hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a drum type washing machine, and more particularly, to a drum type washing machine which can maximize a capacity of a drum without changing an entire size of a washing machine.
[0004] 2. Description of the Related Art
[0005] FIG. 1 is a side sectional view showing a drum type washing machine in accordance with the conventional art, FIG. 2 is a front sectional view showing the drum type washing machine in accordance with the conventional art.
[0006] The conventional drum type washing machine comprises: a cabinet 102 for forming an appearance; a tub 104 arranged in the cabinet 102 for storing washing water; a drum 106 rotatably arranged in the tub 104 for washing and dehydrating laundry; and a driving motor 110 positioned at a rear side of the tub 104 and connected to the drum 106 by a driving shaft 108 thus for rotating the drum 106 .
[0007] An inlet 112 for inputting or outputting the laundry is formed at the front side of the cabinet 102 , and a door 114 for opening and closing the inlet 112 is formed at the front side of the inlet 112 . The tub 104 of a cylindrical shape is provided with an opening 116 at the front side thereof thus to be connected to the inlet 112 of the cabinet 102 , and a balance weight 118 for maintaining a balance of the tub 104 and reducing vibration are respectively formed at both sides of the tub 104 .
[0008] Herein, a diameter of the tub 104 is installed to be less than a width of the cabinet 102 by approximately 30-40 mm with consideration of a maximum vibration amount thereof so as to prevent from being contacted to the cabinet 102 at the time of the dehydration.
[0009] The drum 106 is a cylindrical shape of which one side is opened so that the laundry can be inputted, and has a diameter installed to be less than that of the tub 104 by approximately 15-20 mm in order to prevent interference with the tub 104 since the drum is rotated in the tub 104 .
[0010] A plurality of supporting springs 120 are installed between the upper portion of the tub 104 and the upper inner wall of the cabinet 102 , and a plurality of dampers 122 are installed between the lower portion of the tub 104 and the lower inner wall of the cabinet 102 , thereby supporting the tub 104 with buffering.
[0011] A gasket 124 is formed between the inlet 112 of the cabinet 102 and the opening 116 of the tub 104 so as to prevent washing water stored in the tub 104 from being leaked to a space between the tub 104 and the cabinet 102 . Also, a supporting plate 126 for mounting the driving motor 110 is installed at the rear side of the tub 104 .
[0012] The driving motor 110 is fixed to a rear surface of the supporting plate 126 , and the driving shaft 108 of the driving motor 110 is fixed to a lower surface of the drum 106 , thereby generating a driving force by which the drum 106 is rotated.
[0013] In the conventional drum type washing machine, the diameter of the tub 104 is installed to be less than the width of the cabinet 102 with consideration of the maximum vibration amount so as to prevent from being contacted to the cabinet 102 , and the diameter of drum 106 is also installed to be less than that of the tub 104 in order to prevent interference with the tub 104 since the drum is rotated in the tub 104 . According to this, so as to increase the diameter of the drum 106 which determines a washing capacity, a size of the cabinet 102 has to be increased.
[0014] Also, since the gasket 124 for preventing washing water from being leaked is installed between the inlet 112 of the cabinet 102 and the opening 116 of the tub 104 , a length of the drum 106 is decreased as the installed length of the gasket 124 . According to this, it was difficult to increase the capacity of the drum 106 .
SUMMARY OF THE INVENTION
[0015] Therefore, an object of the present invention is to provide a drum type washing machine which can increase a washing capacity without changing an entire size thereof, in which a cabinet and a tub is formed integrally and thus a diameter of a drum can be increased without increasing a size of the cabinet.
[0016] Another object of the present invention is to provide a drum type washing machine which can increase a washing capacity by increasing a length of a drum without increasing a length of a cabinet, in which the cabinet and a tub are formed integrally and thus a location of a gasket is changed.
[0017] To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a drum type washing machine comprising: a cabinet for forming an appearance; a tub fixed to an inner side of the cabinet and for storing washing water; a drum rotatably arranged in the tub for washing and dehydrating laundry; and a driving motor positioned at the rear side of the drum for generating a driving force by which the drum is rotated.
[0018] The tub is a cylindrical shape, and a front surface thereof is fixed to a front inner wall of the cabinet.
[0019] Both sides of the tub are fixed to both sides inner wall of the cabinet.
[0020] A supporting plate for mounting the driving motor is located at the rear side of the tub, and a gasket hermetically connects the supporting plate and the rear side of the tub, in which the gasket is formed as a bellows and has one side fixed to the rear side of the tub and another side fixed to an outer circumference surface of the supporting plate.
[0021] A supporting unit for supporting an assembly composed of the drum, the driving motor, and the supporting plate with buffering is installed between the supporting plate and the cabinet.
[0022] The supporting unit comprises: a plurality of upper supporting rods connected to an upper side of the supporting plate towards an orthogonal direction and having a predetermined length; buffering springs connected between the upper supporting rods and an upper inner wall of the cabinet for buffering; a plurality of lower supporting rods connected to a lower side of the supporting plate towards an orthogonal direction and having a predetermined length; and dampers connected between the lower supporting rods and a lower inner wall of the cabinet for absorbing vibration.
[0023] The drum is provided with a liquid balancer at a circumference of an inlet thereof for maintaining a balance when the drum is rotated.
[0024] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
[0026] In the drawings:
[0027] FIG. 1 is a side sectional view showing a drum type washing machine in accordance with the conventional art;
[0028] FIG. 2 is a front sectional view showing the drum type washing machine in accordance with the conventional art;
[0029] FIG. 3 is a side sectional view showing a drum type washing machine according to one embodiment of the present invention;
[0030] FIG. 4 is a front sectional view showing the drum type washing machine according to one embodiment of the present invention;
[0031] FIG. 5 is a lateral view showing a state that a casing of the drum type washing machine according to one embodiment of the present invention is cut;
[0032] FIG. 6 is a front sectional view of a drum type washing machine according to a second embodiment of the present invention;
[0033] FIG. 7 is a front sectional view showing a drum type washing machine according to a third embodiment of the present invention;
[0034] FIG. 8 is a longitudinal sectional view of the drum type washing machine according to the third embodiment of the present invention; and
[0035] FIG. 9 is a rear sectional view showing the drum type washing machine according to the third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
[0037] FIG. 3 is a side sectional view showing a drum type washing machine according to one embodiment of the present invention, and FIG. 4 is a front sectional view showing the drum type washing machine according to one embodiment of the present invention.
[0038] The drum type washing machine according to one embodiment of the present invention comprises: a cabinet 2 for forming an appearance of a washing machine; a tub 4 formed integrally with the cabinet 2 and for storing washing water; a drum 6 rotatably arranged in the tub 4 for washing and dehydrating laundry; and a driving motor 8 positioned at the rear side of the drum 6 for generating a driving force by which the drum 6 is rotated.
[0039] The cabinet 2 is rectangular parallelepiped, and an inlet 20 for inputting and outputting laundry is formed at the front side of the cabinet 2 and a door 10 for opening and closing the inlet 20 is formed at the inlet 20 .
[0040] The tub 4 is formed as a cylinder shape having a predetermined diameter in the cabinet 2 , and the front side of the tub 4 is fixed to the front inner wall of the cabinet 2 or integrally formed at the front inner wall of the cabinet 2 . Both sides of the tub 4 are contacted to both sides inner wall of the cabinet 2 or integrally formed with both sides inner wall of the cabinet 2 thus to be prolonged.
[0041] Herein, since both sides of the tub 4 are contacted to both sides inner wall of the cabinet 2 , a diameter of the tub 4 can be increased.
[0042] Also, the supporting plate 12 is positioned at the rear side of the tub 4 and the gasket 14 is installed between the supporting plate 12 and the rear side of the tub 4 , thereby preventing washing water filled in the tub 4 from being leaked.
[0043] The gasket 14 is formed as a bellows of a cylinder shape and has one side fixed to the rear side of the tub 4 and another side fixed to an outer circumference surface of the supporting plate 12 .
[0044] The supporting plate 12 is formed as a disc shape, the driving motor 8 is fixed to the rear surface thereof, and a rotation shaft 16 for transmitting a rotation force of the driving motor 8 to the drum 6 is rotatably supported by the supporting plate 12 . Also, a supporting unit for supporting the drum 6 with buffering is installed between the supporting plate 12 and the inner wall of the cabinet 2 .
[0045] The supporting unit comprises: a plurality of upper supporting rods 22 connected to an upper side of the supporting plate 12 and having a predetermined length; buffering springs 24 connected between the upper supporting rods 22 and an upper inner wall of the cabinet 2 for buffering; a plurality of lower supporting rods 26 connected to a lower side of the supporting plate 12 and having a predetermined length; and dampers 28 connected between the lower supporting rods 26 and a lower inner wall of the cabinet 2 for absorbing vibration.
[0046] Herein, the buffering springs 24 and the dampers 28 are installed at a center of gravity of an assembly composed of the drum 6 , the supporting plate 12 , and the driving motor 8 . That is, the upper and lower supporting rods 22 and 26 are prolonged from the supporting plate 12 to the center of gravity of the assembly, the buffering springs 24 are connected between an end portion of the upper supporting rod 22 and the upper inner wall of the cabinet 2 , and the dampers 28 are connected between an end portion of the lower supporting rod 26 and the lower inner wall of the cabinet 2 , thereby supporting the drum 6 at the center of gravity.
[0047] A diameter of the drum 6 is installed in a range that the drum 6 is not contacted to the tub 4 even when the drum 6 generates maximum vibration in order to prevent interference with the tub 4 at the time of being rotated in the tub 4 .
[0048] Operations of the drum type washing machine according to the present invention are as follows.
[0049] If the laundry is inputted into the drum 6 and a power switch is turned on, washing water is introduced into the tub 6 . At this time, the front side of the tub 6 is fixed to the cabinet 2 and the gasket 14 is connected between the rear side of the tub 6 and the supporting plate 12 , thereby preventing the washing water introduced into the tub 6 from being leaked outwardly.
[0050] If the introduction of the washing water is completed, the driving motor 8 mounted at the rear side of the supporting plate 12 is driven, and the drum 6 connected with the driving motor 8 by the rotation shaft 16 is rotated, thereby performing washing and dehydration operations. At this time, the assembly composed of the drum 6 , the driving motor, and the supporting plate 12 is supported by the buffering springs 24 and the dampers 28 mounted between the supporting plate 12 and the inner wall of the cabinet 20 .
[0051] FIG. 6 is a front sectional view of a drum type washing machine according to a second embodiment of the present invention.
[0052] The drum type washing machine according to the second embodiment of the present invention has the same construction and operation as that of the first to embodiment except a shape of the tub.
[0053] That is, the tub 40 according to the second embodiment has a straight line portion 42 with a predetermined length at both sides thereof. The straight line portion 42 is fixed to the inner wall of both sides of the cabinet 2 , or integrally formed at the wall surface of both sides of the cabinet 2 .
[0054] Like this, since the tub 40 according to the second embodiment has both sides fixed to the cabinet 2 as a straight line form, the diameter of the tub 40 can be increased. Accordingly, the diameter of the drum 6 arranged in the tub 40 can be more increased.
[0055] FIG. 7 is a front sectional view showing a drum type washing machine according to a third embodiment of the present invention, FIG. 8 is a longitudinal sectional view of the drum type washing machine according to the third embodiment of the present invention, and FIG. 9 is a rear sectional view showing the drum type washing machine according to the third embodiment of the present invention.
[0056] The drum type washing machine according to the third embodiment of the present invention comprises: a cabinet 2 for forming an appearance of a washing machine; a tub 50 formed integrally with the cabinet 2 and for storing washing water; a drum 6 rotatably arranged in the tub 50 for washing and dehydrating laundry; and a supporting unit positioned at the rear side of the tub 50 and arranged between the supporting plate 12 to which the driving motor 8 is fixed and the cabinet 2 for supporting the drum 6 with buffering.
[0057] The tub 50 is composed of a first partition wall 52 fixed to the upper front inner wall and both sides inner wall of the cabinet 2 ; and a second partition wall 54 integrally fixed to the lower front inner wall and both sides inner wall of the cabinet 2 .
[0058] The first partition wall 52 of a flat plate shape is formed at the upper side of the cabinet 2 in a state that the front side and both sides are integrally formed at the inner wall of the cabinet 2 or fixed thereto. Also, the second partition wall 54 of a semi-circle shape is formed at the lower side of the cabinet 2 in a state that the front side and both sides are integrally formed at the inner wall of the cabinet 2 or fixed thereto.
[0059] The supporting unit comprises: a plurality of upper supporting rods 56 connected to the upper side of the supporting plate 12 and having a predetermined length; buffering springs 58 connected between the upper supporting rods 56 and the upper inner wall of the cabinet 2 for buffering; a plurality of lower supporting rods 60 connected to the lower side of the supporting plate 12 and having a predetermined length; and dampers 62 connected between the lower supporting rods 60 and the lower inner wall of the cabinet 2 for absorbing vibration.
[0060] Herein, the upper supporting rods 56 are bent to be connected to the upper side of the supporting plate 12 and positioned at the upper side of the first partition wall 52 , and the buffering springs 58 are connected to the end portion of the upper supporting rods 56 . Also, the lower supporting rods 60 are bent to be connected to the lower side of the supporting plate 12 and positioned at the lower side of the second partition wall 54 , and the dampers 62 are connected to the end portion of the lower supporting rods 56 .
[0061] In the drum type washing machine according to the present invention, a size of the drum can be maximized by fixing the tub in the cabinet, thereby increasing washing capacity of the drum without increasing a size of the cabinet.
[0062] Also, since the front surface of the tub is integrally formed at the inner wall of the cabinet and the gasket is installed between the rear surface of the tub and the supporting plate, a length of the drum can be increased and thus the washing capacity of the drum can be increased.
[0063] As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the appended claims. | A drum type washing machine is provided. The drum type washing machine may include a cabinet, a tub fixed to an inner side of the cabinet, a drum rotatably arranged in the tub, and a driving motor positioned at a rear side of the drum for generating a driving force that rotates the drum. The washing machine may also include a supporting plate to rotatably support a rotational shaft extending between the motor and the drum, and a plurality of supporters connected between the supporting plate and the cabinet. Such an arrangement may increase washing capacity by increasing a diameter of the drum without increasing an external size of the cabinet. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to PCT/EP2013/058216 filed Apr. 19,2013, which claims priority to French application 1253591 filed Apr. 19, 2012, both of which are hereby incorporated in their entireties.
TECHNICAL FIELD
[0002] The present invention relates to a support system for an equipment item on a concrete slab in a machine room of a power station. It also relates to a method for producing such a system.
BACKGROUND
[0003] In the electrical engineering production installations, equipment items are installed in a machine room of a power station. Such equipment items comprise, for example, heat exchangers, reheaters or pumps. Some equipment items take the form of a large cylinder that extends horizontally. Two feet are provided close to each of the ends to place the equipment item on a slab of the installation. The slab can be produced directly on the ground or be a floor between two rooms. These equipment items are very heavy, their weight being of the order of tens or even hundreds of tons.
[0004] It is generally planned to install these equipment items at the time of the construction of the building which shelters them. The concrete slab is first of all poured, the equipment item is put in place then a further floor on top of the equipment item is produced.
[0005] It is planned to place the equipment item on plinths made of a single piece with the slab, each plinth supporting a foot of the equipment item. The top surface of this plinth has to be of good geometrical quality. Furthermore, it must include anchoring elements in order to establish a mechanical link between the foot and the plinth. These elements must be positioned accurately in order to correspond to the geometry of the equipment item.
[0006] For this, provision is made to produce the plinth with formwork so that the plinth can be poured at the same time as the slab. A reservation is also provided in the top part of the plinth. Then, the anchoring elements are placed accurately in the reservation and in a second phase, concrete is poured to fix the anchoring elements. The equipment item is then put in place when concrete has hardened sufficiently.
[0007] This method therefore entails two concrete pouring phases, each time with waiting times for the hardening which are measured in weeks. Now, it is important not to delay the construction work site, in particular the construction of the upper floor which can be done only when the equipment items are in place.
[0008] The invention aims to provide a support system for an equipment item on a concrete slab which is quick to implement, while retaining the equipment item positioning accuracy.
SUMMARY
[0009] With these objectives in view, the subject of the invention is a support system for an equipment item on a concrete slab comprising at least one raised block relative to the slab and of a single piece with the slab, wherein the block includes a metal belt delimiting the vertical walls of the block and a metal support fastened to the belt and capping the block to receive a foot of the equipment item.
[0010] By producing the block with a metal belt, a means is available to fasten the support thereto in the desired position, in particular altitude-wise, and without it being necessary to carry out a second concrete pouring phase. The equipment items can therefore be placed at the right altitude with no second concrete pouring phase, which makes it possible to accelerate the completion of the work site.
[0011] According to an additional feature, the belt includes connection means protruding inward to link the belt to the concrete. The mechanical link between the belt and the concrete of the block is thus perfectly assured.
[0012] According to one embodiment, the connection means are studs welded onto the belt. This technique is more than adequately proven and makes it possible to obtain the desired result. The studs generally have a cylindrical body and a head that is wider than the body. The body is welded at the end, at right angles to the internal surface of the belt. The block is optionally complemented with conventional concrete reinforcement, but in most case, the reinforcement of the block is not necessary.
[0013] According to a particular arrangement, the support comprises drop edges at its periphery, the drop edges surrounding the belt and being fastened thereto by welding. The support can be adjusted in position by sliding vertically over the belt. Once the position is adjusted, the drop edges are welded onto the belt, which ensures an excellent mechanical link between the belt and the support, with the desired position accuracy.
[0014] To support equipment items comprising two feet, the support system comprises, for example, two blocks distributed over the slab in a main direction, one of the blocks comprising sliding means for the foot that it supports to slide on the block in the main direction. The system is thus able to accept a longitudinal expansion of the equipment item.
[0015] According to a particular constructive arrangement, the sliding means comprise two rules extending in the longitudinal direction along two parallel guiding faces of the foot. In addition to bearing the foot on the support, the two rules limit the possibilities of the foot slipping sideways, while leaving the foot free to slide on the support in the main direction.
[0016] According to a refinement, at least one of the rules also comprises a tab overhanging a corner face of the foot forming an angle with the correspond guiding face to prevent any lifting of the foot. In addition to the lateral guiding, the rule thus provided with a tab prevents lifting of the foot, so as to ensure the link even in the event of an earthquake.
[0017] Another subject of the invention is a method for producing a support system for an equipment item whereby the following steps are carried out:
installation of a formwork to delimit a block on top of a slab, and reinforcement for the slab and the block, and pouring of concrete for the slab and into the block formwork, the method wherein the formwork is a metal belt, and, after the pouring and the hardening of the concrete, a metal support capping the block to receive a foot of the equipment item is then fastened to the belt.
[0021] According to this method, there is only one concrete pouring step. The support system is thus available more rapidly than in the prior art, according to which two concrete pouring steps were needed. This production method is therefore more rapid.
[0022] According to other features of the method:
the belt is equipped first with connection means between the belt and the concrete; the support is fastened to the belt by welding after its position has been set; the foot is fastened onto the support by welding; this operation does not require any particular preparation of the support or of the foot and it produces a total link between the foot and the support.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The invention will be better understood and other particular features and advantages will become apparent on reading the following description, the description referring to the appended drawings in which:
[0027] FIG. 1 is a side view of an equipment item and of the support system of the invention,
[0028] FIG. 2 is a partial cross-sectional view along the line II-II of FIG. 1 ;
[0029] FIG. 3 is a perspective view of a belt used for the support system of FIG. 1 ;
[0030] FIG. 4 is a cross-sectional view along the line IV-IV of FIG. 1 .
DETAILED DESCRIPTION
[0031] The support system 3 of the invention is implemented for an equipment item 1 as shown schematically in FIG. 1 . Such an equipment item 1 is of cylindrical form and comprises two feet 11 , 12 close to its two ends. Such an equipment item 1 is generally made of steel by boiler making operations.
[0032] The feet 11 , 12 comprise vertical webs and baseplates 33 , 33 ′ having a planar surface 330 , 330 ′ oriented downward.
[0033] The support system 3 comprises two blocks 31 , 32 intended to receive, respectively, the two feet 11 , 12 . The blocks 31 , 32 are of a single piece with a concrete slab 2 which forms a separating floor between a room below 4 , under the floor, and a room above 5 in which the equipment item 1 is placed. The blocks 31 , 32 have a rectangular parallelepipedal form protruding from the slab 2 .
[0034] Referring to FIG. 2 , the block 31 is surrounded by a metal belt 310 , for example made of steel. As FIG. 3 shows, the belt comprises rows of welded studs 311 protruding inward from the belt 310 . The welded studs technique is widely known and used, in particular for the construction of hybrid bridges comprising steel girders and concrete aprons. It will not be detailed more here. The metal belt 310 also comprises anchor bars 3101 extending downward and intended to produce the anchorage for the block 31 , 32 in the concrete of the slab 2 .
[0035] The space delimited by the belt is filled with concrete 312 in continuity with the concrete of the slab 2 .
[0036] The block 31 also comprises a support 35 comprising a metal plate 350 , for example made of steel, and drop edges 351 , of the same nature. The drop edges 351 extend vertically along the metal belt 310 and are fastened thereto by welding. A space is retained between the top part of the concrete of the block 31 and the plate 350 . The block 32 is produced in the same way as the block 31 and comprises a support 35 ′ comprising a plate 350 ′.
[0037] The baseplate 33 rests on the support 35 and is fastened thereto by welding for a first of the two feet 11 , either continuously, as shown in FIG. 2 , or discontinuously. For the case of the second foot 12 , shown in FIG. 4 , the baseplate 33 ′ rests on the support 35 ′, but without being fastened thereto. Instead, the support system 3 comprises two rules 36 extending in the main direction along the edges of the baseplate 33 ′, facing guiding faces 332 . Furthermore, each rule 36 comprises a tab 360 overhanging the baseplate 33 ′ facing a corner face 331 of the foot forming an angle with the guiding face 332 . The tabs 360 thus form an obstacle to any lifting of the second foot 12 .
[0038] For the production of the support system 3 , during the preparation of the slab 2 , the belts 310 are placed in the appropriate positions and reinforcement 20 is put in place. Then, the concrete of the slab 2 and that of the blocks 31 , 32 is poured inside the belts 310 . As soon as the blocks 31 , 32 are accessible, the supports 35 , 35 ′ are put in place by adjusting their position, in particular their level. While maintaining this position, it is fastened by producing weld beads 37 between the drop edges 351 and the belt 310 . It goes without saying that the length and the size of the beads 37 is sufficient to transmit the forces to be supported by the support 35 , 35 ′. The weld beads 37 may be continuous, as represented, or discontinuous.
[0039] Then, the equipment item 1 is put in place such that the feet 11 , 12 bear on the supports 35 , 35 ′. The position of the equipment item 1 is adjusted, then weld beads 34 are produced on the periphery of the baseplate 33 to fasten the baseplate 33 onto the support 35 of the first foot 11 . With regard to the second foot 12 , the rules 36 are put in place along the guiding faces 332 of the baseplate 33 ′ and they are also fastened by weld beads 38 onto the support 35 ′.
[0040] In operation, the equipment item 1 is likely to expand, in particular if it is passed through by fluids at medium and high temperature. This expansion is translated into a variable distance between the two feet 11 , 12 . When this distance varies, the baseplate 33 ′ of the second foot 12 slides on the support 35 ′ by being guided by the rules 36 .
[0041] In case of earthquake, the first block 11 takes up the stresses in any direction. On the second block 12 , the rules 36 prevent the lateral displacement, the tabs 360 prevent the lifting, whereas the longitudinal stresses are taken up by the first block 11 .
[0042] The invention is not limited to the embodiment which has just been described by way of example. The form of the equipment item may be different. It may have only one foot, or, on the contrary, more than two feet. In the latter case, only one will be fixed, the others being designed to slide. | A support system for an equipment item on a concrete slab includes at least one raised block relative to the slab and of a single piece with the slab. The block includes a metal belt delimiting the vertical walls of the block and a metal support fastened to the belt and capping the block to receive a foot of the equipment item. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the priority of PCT/EP2007/063246, filed on Dec. 4, 2007, which claims priority to German Application No. 10 2006 062 376.2, filed Dec. 19, 2006, the entire contents of which are hereby incorporated in total by reference.
FIELD OF THE INVENTION
The present invention relates to a method for reducing speckle patterns in a three-dimensional holographic reconstruction of a three-dimensional scene, and to a holographic display device used to implement that method.
This invention can be applied in conjunction with methods which allow complex wave fronts of a three-dimensional scene (3D scene) to be recorded and reconstructed with the help of holography, preferably using laser light in real-time or in near-realtime in holographic display devices, where the reconstruction can be seen from a virtual observer window.
BACKGROUND OF THE INVENTION
Holography allows a three-dimensional object or a moving 3D scene to be recorded and optically represented using wave-optical methods. The 3D scene is encoded on a light modulator which serves as a carrier medium. Due to the illumination with light waves which are capable of generating interference, each point of the encoded 3D scene forms a point of origin of light waves which interfere with each other, and which, as a resultant light wave front, spatially reconstruct the 3D scene as if it was generated by light propagating from a real object in space. The holographic reconstruction of the object or the 3D scene is preferably realised with the help of a projection device and/or an optical reconstruction system by illuminating a carrier medium with normally sufficiently coherent light.
In this document, the 3D scene is reconstructed in a holographic display device with an observer window, which here is a visibility region in a periodicity interval of the complex-valued wave front located in the rear focal plane of a reconstruction means in a reconstruction space. The reconstruction of the 3D scene can be viewed from the observer window by a left and/or right eye of an observer. The size of the observer window in front of a display means is defined; it is typically at least as large as an eye pupil.
Seen from the wave-optical point of view, the observer window is represented by either a direct or an inverse Fourier transform or Fresnel transform of a hologram encoded on a carrier medium, or by the image of a wave front encoded on a carrier medium in a reconstruction space, where the observer window comprises only one diffraction order of a periodical reconstruction. The hologram or the wave front are computed from the 3D scene such that, within the one diffraction order which is used as the visibility region, cross-talking of other diffraction orders into the observer window is prevented, which would typically occur in reconstructions when using light modulators. In conjunction with an arrangement or a method for suppressing higher diffraction orders, 3D scenes can be consecutively presented in a multiplexed process to a left and to a right eye of an observer without any cross-talking.
Moreover, a multiplexed process with the aim to serve multiple persons only becomes possible thereby.
Carrier or recording media for holograms and complex wave fronts of a 3D scene include spatial light modulators, such as LCD, LCoS etc., which modulate the phase and/or amplitude of incident light. The refresh frequency of the carrier medium must be sufficiently high in order to be able to reconstruct moving 3D scenes.
The values which are encoded into pixels which are arranged in regular patterns on the carrier medium, can originate from a real object or be a computer-generated hologram (CGH).
The observer can view the reconstruction of the 3D scene by looking directly on to the carrier medium. In this document this arrangement is referred to as direct-view display. Alternatively, the observer can look on to a screen on to which either an image or a transform of the values encoded on the carrier medium is projected. In this document, this arrangement is referred to as a projection display.
Both the screen in the projection display and the carrier medium in the direct-view display are meant by the term ‘screen’ below.
Due to the discrete recording and because of the effects of deflection, the reconstruction of the hologram is only possible within one periodicity interval of the reconstruction of a wave front, said periodicity interval being defined by the resolution of the carrier medium. The reconstruction is typically repeated showing irregularities in adjacent periodicity intervals.
Disturbing patterns, which are also known as speckle patterns or granulation, occur when using coherent laser light for illuminating a light modulator. Speckle can be described as a granulation-like interference pattern which is created by interference of multiple light waves with statistically irregularly distributed phase differences.
The reconstruction of a hologram is adversely affected by the speckle patterns. The 3D scene is typically discretely scanned for hologram computation, because it can only be recorded discretely on the carrier medium. Certain encoding methods, where information of the 3D scene is recorded in a suitable manner on the carrier medium, generally make possible a reconstruction where the reconstruction is fully identical to the scanned object at the positions of the scan points. The physical reconstruction results in a continuous gradient, also between the scan points. Deviations from the light intensity gradient in the object occur between the scan points, so that the reconstruction exhibits speckle patterns, which reduce the quality of the reconstruction. This is in particular the case when computing the hologram with a random phase of the object points, which is, however, advantageous for certain other reasons.
Reducing the speckle patterns in the reconstruction of the 3D scene can be realized by temporal or/and spatial averaging, where the reconstruction is created from values of a 3D scene encoded on an external carrier medium or from hologram values which are computed in another suitable way. The eye of the observer always averages multiple reconstructions presented to him with different speckle patterns, resulting in a perceivable reduction of this disturbance.
In document DE 195 41 071 A1, a rotating rectangular glass plate is put into the optical path in order to average the granulation when checking a hologram. The speckles do not appear disturbing anymore because the glass plate rotates at a frequency which is adapted to that of a detector. However, such a method can only be applied for reducing a two-dimensional, plane speckle pattern, where the diffusing screen must be disposed in the plane of the speckle pattern.
As regards temporal averaging in order to reduce speckle patterns of a 3D scene, a known method is that the 3D scene is computed with a given number of different random phases, and the respective holograms are represented on the carrier medium one after another at a fast pace. Due to the multiple hologram computations the computational load increases considerably and the refresh frequency of the carrier medium would also have to increase significantly when representing the holograms, which is undesired.
As regards spatial averaging, it is generally known from the literature that a carrier medium is divided into multiple independent sections, where repetitions of subholograms which are computed from the same object, but with different object phases, are written next to each other and/or below each other. The eye of the 20 observer averages different speckle patterns of the individual reconstructions of the computed sub-holograms generated with a Fourier transformation or Fresnel transformation, so that the resulting speckle pattern appears weakened.
However, this method cannot be applied to a holographic display with an observer window, as described by the applicant in document DE 103 53 439 A1 and on which this invention is based. A complex-valued light distribution of the diffraction image of an object, e.g. a 3D scene, is computed in the observer window. Transformations of individual object planes, into which the 3D scene is virtually sliced, are realised and added in the observer window in order to achieve this. The transformations correspond with the optical propagation of light between the sliced object planes and the plane comprising the observer window. This method has the effect that each object point is assigned with a confined localised section on a screen, to which the information for the reconstruction of this point is written. This is necessary to allow a correct reconstruction from the observer window.
Encoding multiple sub-holograms, which are computed from the 3D scene next to each other and/or below each other on the screen, as suggested in the prior art, would have the effect that the hologram values which correspond to an object point are repeated in different sections on the screen. This is not possible though in conjunction with the principle of making visible the reconstructed 3D scene from the observer window. It is a general disadvantage of a spatial repetition of subholograms that the resolution of each individual sub-hologram is reduced in a given carrier medium.
SUMMARY OF THE INVENTION
An object of the claimed invention is to significantly reduce the speckle patterns which occur when reconstructing a 3D scene in a holographic display device with a virtual observer window, and to provide a near-real-time method where a carrier medium with a conventional refresh frequency can be used.
The claimed invention is generally based on a method where a controllable light modulator, on which a hologram of a 3D scene is encoded, is illuminated with sufficiently coherent light, where an optical reconstruction system transforms modulated light into an observer window or into an eye position in a reconstruction space and reconstructs the 3D scene in a reconstruction space, and where the illumination is controlled with the help of a control means.
An observer window in accordance with the claimed invention is based on for reconstructing the 3D scene can be considered to be identical with the eye position as the position in the reconstruction space where different light distributions of the complex-valued wave fronts of the encoded hologram are created. The eyes of the observer must be in that eye position in order to be able to see the reconstructed 3D scene.
According to the claimed invention, an object is solved by this method, where the control means affects at least one characteristic of the coherent light such that multiple complex-valued wave fronts with different wavelengths pass the light modulator, where they are modulated with the encoded hologram values and where the modulated complex-valued wave fronts are transformed into the eye position by the optical reconstruction system and create multiple reconstructions of the 3D scene at the same position in the reconstruction space with slightly different speckle patterns, said reconstructions being averaged from the eye position as a single reduced-speckle reconstruction of the 3D scene.
By affecting the wavelength of the light, multiple slightly modified reconstructions of the same 3D scene with slightly modified speckle patterns can preferably be created.
According to an embodiment of the method, the following process steps are performed:
An illumination means generates a fast-paced sequence of light pulses, controlled by the control means, in order to illuminate the optical reconstruction system and the light modulator, where the wavelengths of the light pulses can differ slightly, The fast-paced sequence of light pulses passes the light modulator, where the complex-valued wave fronts of the light pulses are modulated with the encoded hologram values, and The fast-paced sequence of the modulated complex-valued wave fronts is transformed into the eye position of the reconstruction space and creates multiple reconstructions of the same 3D scene one after another at a fast pace at the same position in the reconstruction space.
According to a further embodiment of this invention, the method can alternatively comprise the following process steps, while the same result is obtained:
Multiple illumination means simultaneously emit coherent light which is affected by the control means such that multiple complex-valued wave fronts with slightly different wavelengths simultaneously illuminate both the optical reconstruction system and the light modulator, The complex-valued wave fronts with slightly different wavelengths simultaneously pass the light modulator where they are modulated with the encoded hologram values, and Multiple modulated wave fronts are simultaneously transformed into the eye position of the reconstruction space and simultaneously create and overlap the different reconstructions of the same 3D scene at the same position in the reconstruction space.
Lasers are preferably used as illumination means, said lasers being disposed in a spatially interleaved manner, such that the coherent light of an individual illumination means is imaged with the help of separate optical imaging systems into separate optical fibres, and which is subsequently united in a single optical fibre in order to simultaneously illuminate the optical reconstruction system and the light modulator.
This provides in a simple manner an illumination means which provides coherent light with slightly different wavelengths for simultaneously illuminating the light modulator.
A method according to the claimed invention can be applied separately for a right eye and a left eye of an observer, e.g. one after another.
The different wavelengths in the described methods are modified in a defined manner or subjected to a random fluctuation within given limits by the control means.
A holographic display device for implementing the method includes one after another the following means, seen in the direction of light propagation:
An illumination means that emits coherent light pulses with slightly different wavelengths one after another at a fast pace for illuminating an optical reconstruction system and a light modulator, An optical reconstruction system for transforming a fast-paced sequence of modulated complex-valued wave fronts into an eye position in a reconstruction space and for creating multiple reconstructions of the same 3D scene one after another at a fast pace at the same position in a reconstruction space, An encoding means in the form of a light modulator, on to which a hologram of a 3D scene is encoded, and A control means for controlling the illumination means, the encoding means and the optical reconstruction system.
According to another embodiment, the holographic display device according to this invention for implementing the method includes one after another the following means, seen in the direction of light propagation:
Multiple illumination means which simultaneously emit coherent light with slightly different wavelengths for simultaneously illuminating an optical reconstruction system and a light modulator, An optical reconstruction system for simultaneously transforming multiple modulated complex-valued wave fronts of a hologram into an eye position in a reconstruction space and for simultaneously creating and overlapping multiple reconstructions of the same 3D scene at the same position in a reconstruction space, An encoding means in the form of a light modulator, on to which the hologram of the 3D scene is encoded,
An imaging means which comprises multiple optical imaging systems which are arranged adjacently in at least one dimension, for imaging the coherent light of the illumination means into multiple optical fibres, and
A control means for controlling the illumination means, the encoding means and the optical reconstruction system.
An essential feature of the present invention is that the minor modification of the wavelengths ranges within several nanometres. Such a modification of the wavelengths is sufficient to create multiple, slightly modified reconstructions of the same 3D scene with modified speckle patterns in the reconstruction space. The respective eye of the observer averages from the eye position or from the observer window the speckle patterns and sees only one single reduced-speckle reconstruction of the original 3D scene.
A holographic display device for reducing speckle patterns is for example a holographic display.
A holographic display device with an observer window differs substantially from a conventional Fourier hologram or from a Fresnel hologram as regards the wavelength dependence of the holographic reconstruction.
In a plane reconstruction of a Fourier hologram, the reconstruction would be sized differently as the wavelength of the light changes. The larger the wavelength the larger would be the entire reconstruction. Individual object points would then be displaced laterally relative to a reconstruction at a smaller wavelength. When mixing multiple wavelengths, speckle would be reduced if the displacement of the object points with respect to each other was greater than the size of the speckles.
In the holographic display device with an observer window, it is this observer window that lies in the Fourier plane of the hologram. A change in the wavelength results in a change in the size of the observer window.
Initially, this has the following effects: if the eye pupil were situated at the edge of the observer window of the greatest wavelength, the observer would only see a reconstruction of that wavelength. If the eye pupil were situated within the observer window of the smallest wavelength, he would see the reconstruction of all wavelengths.
However, in contrast to an ordinary Fourier hologram or Fresnel hologram, the lateral position of a reconstructed object point of the three-dimensional scene does not change depending on the wavelength.
The individual object points are encoded as lenses in the hologram. The wavelength is taken into account in this code. An encoded lens which has a certain focal length at a certain wavelength, changes its focal length inversely proportional to the wavelength. A change in the wavelength thus results in a change in the depth of the reconstructed object point.
Speckle reduction using different wavelengths is thus realised in a holographic display device with an observer window by way of changing the depth of the reconstruction as the wavelength changes.
In particular, if the eye pupil moves within the observer window, the wavelength-dependent change in depth will result in a parallax effect outside the centre of the observer window. The observer will then see from his eye position the reconstruction of the different wavelengths side by side.
Speckle is particularly reduced if this parallax is at least as large as the speckle size. Speckle reduction using different wavelengths is thus improved from the centre towards the edge of the observer window.
The described speckle reduction effect is smaller than that in a conventional Fourier hologram. The change in the wavelengths must thus be in the range of several nanometres. Typical sizes can be 10 or 20 nanometres.
A wavelength range which is large enough to cause a perceivably blurred reconstruction, i.e. to impair quality, in an ordinary Fourier hologram, can cause a good reconstruction quality with reduced speckle patterns in a holographic display device with an observer window.
By way of adequately designing the individual display components, in particular the optical components, the display can be realised either as a projection display or as a direct-view display.
Both, lasers and LEDs can be used as illumination means in the various embodiments of the present invention. An inherently wide-banded light source like a LED can already help to reduce speckle patterns because of its spectrum. However, the laser has the advantages that it can be approximated as a point light source and that it provides a higher performance.
A further advantage of the present invention is that the hologram must only be encoded once, in contrast to the prior art, and that it does not have to be recomputed several times which results in a reduction of computing time.
BRIEF DESCRIPTION OF THE DRAWINGS
The claimed invention will be described in detail below with the help of embodiments, in conjunction with the accompanying drawings, wherein
FIG. 1 shows a schematic top view of a holographic direct-view display according to a first embodiment, and
FIG. 2 shows a schematic top view of a holographic direct-view display according to a second embodiment.
Like numerals denote like components in the individual Figures and accompanying description.
DETAILED DESCRIPTION
The observer window this invention is based on for reconstructing the 3D scene is identical to the visibility region with an eye position which represents the position in the reconstruction space to which multiple intensity distributions of the complex-valued wave fronts of the encoded hologram are transformed one after another at a fast pace or simultaneously, said intensity distributions having slightly different wavelengths. One eye of an observer must be situated in this eye position to enable him to see the reconstructed 3D scene.
FIG. 1 is a schematic and simplified top view showing a first possible embodiment of a holographic direct-view display. An illumination means L in the form of a laser, an optical reconstruction system RO in the form of a transformation lens, and a pixilated light modulator SLM are disposed one after another, seen in the direction of light propagation. A reconstruction of a 3D scene is represented in a frustum-shaped reconstruction space that stretches between the light modulator SLM and an eye position PE. The reconstruction of the 3D scene is entirely visible to an observer eye at this eye position PE, which lies in the rear focal plane of the transformation lens. The illumination and thus also the components in the optical path which are touched by the light are controlled by a control means CM.
The light modulator SLM and the transformation lens, which is arranged in front of it, are illuminated with sufficiently coherent light by a laser which is externally controlled by the control means CM. The direction of light propagation is indicated by an arrow. By quickly switching on and off the laser, the control means CM causes it to generate a fast-paced sequence of coherent light pulses, where each pulse represents a complex-valued wave front and where the light pulses have different wavelengths. The light pulses are schematically represented by multiple intensity curves on the arrow line in FIG. 1 .
The wavelengths of the individual, only slightly different light pulses can be modified in a defined manner by respectively programmed instructions in the control means CM or exposed to a random fluctuation within a given limit. The modification of wavelengths is preferably realised within a few nanometres, so that the subsequent reconstructions and the respective speckle patterns do not have major differences when they are averaged.
The fast-paced sequence of light pulses are modulated with the encoded hologram values of a 3D scene in the light modulator SLM and are transformed one after another at a fast pace into the rear focal plane BE of the transformation lens arranged in front of the light modulator SLM, where the transformation lens also represents the optical reconstruction system RO. The rear focal plane BE of the optical reconstruction system RO lies in a reconstruction space where the eye position PE is also always situated. The modulated complex-valued wave fronts create multiple reconstructions of the same 3D scene one after another at a fast pace with slightly different speckle patterns at the same position in the reconstruction space. The reconstructions are perceived by an observer eye from the eye position PE as a single reconstruction of the 3D scene with an averaged speckle pattern.
Although fast-paced sequences of light pulses are generated, the same hologram can always preferably be displayed on the light modulator with conventional refresh frequency. The hologram computation then only has to be realised at this refresh frequency.
The embodiment according to FIG. 1 has another major advantage: the number of reconstructions of the 3D scene can be increased freely without the need of any additional components in order to reduce the occurring speckle patterns.
FIG. 2 is a schematic and simplified top view showing a second possible embodiment of a holographic direct-view display. Illumination means L 1 , L 2 and L 3 in the form of three lasers arranged side by side, an imaging means AM in the form of three adjacently arranged one-dimensional optical imaging systems AO, an optical reconstruction system RO in the form of a transformation lens, and a pixelated light modulator SLM are disposed one after another, seen in the direction of light propagation. This embodiment allows three slightly different reconstructions with slightly different speckle patterns to be created in order to be averaged by an eye. It goes without saying that the number of lasers and the respective optical imaging systems can be freely increased in order to simultaneously create a larger number of reconstructions and to improve the speckle reduction by averaging.
The reconstruction of the 3D scene is represented in a frustum-shaped reconstruction space that stretches between the light modulator SLM and the eye position PE. The reconstruction of the 3D scene is entirely visible to an observer eye at the eye position PE, which lies in the rear focal plane of the transformation lens. The illumination and thus also the components in the optical path which are touched by the light are controlled by a control means CM.
Initiated by the programme in the control means CM, three lasers with slightly different wavelengths emit sufficiently coherent light, which is imaged by a corresponding optical imaging system into an optical fibre, for example. Both the lasers and the optical imaging systems AO are adjacently arranged in one dimension. The lasers can alternatively be arranged in two dimensions, as a composite component, if there are many of them. A suitable imaging means for two-dimensional imaging of the two-dimensional composite component is preferably formed as matrix lens array.
The light of the optical fibres is united in a single optical fibre LLF and illuminates, controlled by the programme in the control means CM, the transformation lens and the light modulator SLM with combined light with three slightly different wavelengths. The transformation lens transforms the light with different wavelengths into its rear focal plane BE, to the eye position PE. If an observer eye is situated at this position, three complex-valued wave fronts with different wavelengths will be provided simultaneously so as to create three reconstructions of the 3D scene at the same time with the help of the transformation lens. Because the three reconstructions with slightly different speckle patterns are simultaneously created and overlapped at the same position in the reconstruction space, the eye averages these reconstructions and perceives only one single reconstruction of the 3D scene with reduced speckle pattern.
A light modulator with conventional refresh frequency can also be used for the method according to FIG. 2 , and the hologram computation may preferably be realised only at this frequency.
The Fourier transformation is preferably used in the method according to the present invention, because it can be implemented in programmes easily and can be realized very precisely in optical systems.
The hologram can be variably encoded in the embodiments in FIG. 1 and FIG. 2 , so that the reconstructions of the 3D scene are visible in front of and/or behind the screen. The light modulator SLM here simultaneously fulfils the function of the screen.
In FIG. 1 and FIG. 2 , the position information of an observer eye is typically detected by a position detection system (not shown) and is processed by the control means CM. The details shall be omitted here.
A method for reducing speckle in a reconstruction of a 3D scene in a holographic direct-view display, as described in the embodiments, may also be applied to a holographic projection display, according to the claimed invention. | A method for reducing speckle patterns of a three-dimensional holographic reconstruction is disclosed. A controllable light modulator into which a hologram of a three-dimensional scene is coded is illuminated by coherent light, a reconstruction lens transforms the modulated light into an eye position and reconstructs the three-dimensional scene in a reconstruction space and a control means controls the illumination. This provides a holographic reproduction device in which the speckle patterns occurring during reconstruction of a three-dimensional scene are reduced. According to one embodiment, a next-to-real time method is presented using a carrier medium of conventional image refresh rate. | 6 |
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