An olefin oxidation catalyst comprising a carrier, and silver and an alkali metal supported thereon, wherein the content of organic substances is less than 0.1 wt %.

The present invention relates to a silver catalyst useful for the production of ethylene oxide by a gas phase oxidation of ethylene with oxygen, and a process for the preparation of the catalyst. Ethylene oxide is co-polymerized with an active hydrogen compound for a non-ionic surfactant, or it is converted into ethylene glycol or polyethylene glycol by an addition of water which is used as a starting material for a polyester or polyurethane type polymer or as an antifreezing agent for engines.
A silver catalyst has been used as a catalyst which is useful for industrially producing ethylene oxide by a gas phase oxidation of ethylene with oxygen. In order to efficiently produce ethylene oxide, a demand for improvement of such a silver catalyst has been strong, and it is desired to develop a catalyst having higher activity, higher selectivity and longer life. Accordingly, various proposals have been made for improvements in e.g. a method of supporting silver, and alkali metal or other additive components serving as a reaction accelerator of ethylene oxide production, and a carrier development.
For supporting silver on a carrier, it is considered preferable to use silver in the form of a complex solution by means of a complex-forming compound. As such a method, the following has been proposed. For example, there is a method of using an aqueous solution of a silver complex having monoethanolamine bonded to silver nitrate (JP-B-46-19606), a method of using an aqueous silver lactate solution (JP-B-47-20079), a method of using an ethanol solution of a silver carbonate/acetylacetone complex (JP-B-49-26603), a method of using an aqueous solution of a silver oxalate/ethylenediamine, monoethanolamine complex (JP-A-47-11467), a method of using a silver oxalate/ethylenediamine, 1,3-diaminopropane complex (JP-A-61-54242), or a method of using a toluene solution of silver neodecanoate (JP-A-60-244338).
In order to have silver supported on a carrier by means of such a complex-forming compound, it is common that a carrier is impregnated with a solution of a complex of silver, and then the impregnated carrier is heat-treated in a gas to decompose the silver complex. For such heat treatment, a method is employed which comprises depositing a layer of the impregnated carrier and permitting a heated gas to pass through the deposited layer. This method can be carried out by a batch system i.e. by a fixed bed system. However, for the production on an industrial scale, a method is commonly employed wherein the impregnated carrier is put on e.g. a belt and continuously passed through a heating apparatus.
As the gas for heating, an inert gas such as nitrogen, helium, argon or superheated steam, or a mixture of such an inert gas with air or oxygen, may be employed.
As an apparatus to be used for such heat treatment, a gas flow band dryer as disclosed, for example, in xe2x80x9cChemical Engineering Handbook (5th edition)xe2x80x9d 1988, compiled by Society of Chemical Engineers, Japan, published by Maruzen Co., Ltd. on Mar. 18, 1988, p. 674-675, may be employed, and the impregnated carrier is heated by circulating a heated gas.
However, when a complex-forming compound is used to prepare a silver complex for silver impregnation on a carrier, the gas which is circulated in the heat treatment apparatus, will contain the complex-forming compound formed by the decomposition of the silver complex, or its decomposed products, and the solvent used to dissolve the complex. Accordingly, if the circulation of the gas is continued, they will be accumulated in a large amount in the gas, and the complex-forming agent or its decomposed products are likely to deposit on the catalyst, or the catalyst tends to be hardly completely dried.
Accordingly, it is necessary to discharge the gas passed through the deposited layer of the impregnated carrier out of the system in a certain proportion. However, if the amount of such discharge increases, the amount of a heated gas to be introduced afresh to supplement the discharged amount, will have to be increased, such being uneconomical. Accordingly, it is known to heat the impregnated carrier while discharging about 10 vol % of the gas passed through the deposited layer, taking into consideration the catalytic performance of the obtained catalyst.
In the catalyst obtained by such a method, organic substances which are considered to be the complex-forming compound and its decomposed products, remain in an amount of from 0.1 to 0.3 wt %. However, in the production of ethylene oxide by using the catalyst immediately after the preparation of the catalyst, they present no adverse effect, and ethylene oxide can be produced at a high selectivity.
The amount of the catalyst to be used in an installation for producing ethylene oxide on an industrial scale, is usually as much as a few tens tons. Accordingly, it is usual that the production of the catalyst is started a few months ahead of using the catalyst, and it takes at least a few months to produce the necessary amount of the catalyst, although it depends also on the capacity for the production of the catalyst. Further, in a case where the installation for the production of the catalyst is located far from the installation for the production of ethylene oxide, it may take a few months until the catalyst is delivered to the installation for the production of ethylene oxide. For such reasons, it is common that the catalyst is stored for about one year before it is actually used for the production of ethylene oxide.
However, there is a problem that if a catalyst which is capable of producing ethylene oxide at high selectivity when it is used within one year after the production, is used after being stored for a long period of time, the selectivity for ethylene oxide decreases by a few percent. Such a decrease in the selectivity gives a serious adverse effect from the viewpoint of the production cost of ethylene oxide on an industrial scale.
Accordingly, the object of the present invention is to provide a catalyst useful for the production of ethylene oxide, of which the performance will not decrease even when stored for a long period of time, and a process for the preparation of the catalyst. Thus, the catalyst invented shows a stable performance against storage.
The present inventor has conducted an extensive study to solve the problems of the storage degradation, and as a result, have found that the above problems are somehow attributable to an organic substance which results from a complex-forming compound used for supporting silver on the carrier and its decomposition product remaining in a trace amount in the catalyst in the conventional process for producing a catalyst for the production of ethylene oxide. On the basis of this discovery, the present invention has been accomplished.
Namely, according to the present invention, it is possible to produce a catalyst which maintains as high performance after long storage as that on its preparation, by impregnating a carrier with a solution having silver dissolved in the form of a complex with an organic compound and heating this impregnated carrier by a heated gas at a temperature of from 120 to 500xc2x0 C., until the content of the organic compound will be less than 0.1 wt %, in the production of an olefin oxidation catalyst having at least silver and an alkali metal supported on a carrier, particularly a catalyst for producing ethylene oxide by ethylene oxidation.
Now, the present invention will be described in detail.
An oxidation catalyst for olefin, particularly ethylene, of the present invention is a catalyst having at least silver and an alkali metal supported on a carrier. As the alkali metal, cesium, or a combination of cesium and another alkali metal, such as lithium, is preferred.
As the carrier, a refractory such as alumina, silicon carbide, titania, zirconia or magnesia, may be mentioned. Among them, a refractory comprising xcex1-alumina as a main component is preferred from the viewpoint of the performance of the final catalyst.
The carrier may be used, as it is, for supporting silver. However, it is preferred that an alkali metal is preliminarily supported thereon, and then silver is supported thereon. In general, a catalyst having a better performance can be obtained by supporting silver on a carrier on which an alkali metal is preliminarily supported. Most preferably, silver and an alkali metal are supported on a carrier on which an alkali metal is preliminarily supported. In order to have an alkali metal supported on a carrier, the carrier may be immersed in a solution containing an alkali metal, or sprayed with the solution, to have the carrier impregnated with the solution, and then, the impregnated carrier is heated to remove the solvent.
The alkali metal to be supported on a carrier includes, for example, cesium, lithium and sodium, preferably combination of cesium and lithium. Further, the heat treatment can be carried out at any temperature so far as the solvent of the impregnated solution can be evaporated and removed. However, industrially, it is preferably carried out at a temperature of from 120 to 500xc2x0 C., particularly preferably from 120 to 250xc2x0 C., by means of a heated gas. The heated gas may, for example, be an inert gas such as nitrogen, helium, argon or superheated steam, or a mixture of an inert gas with oxygen such as air. Among them, it is preferred to use superheated steam, whereby the distribution of the alkali metal in the finally obtainable catalyst will be uniform. In the present invention, silver, preferably silver and an alkali metal, are supported on a carrier, preferably a carrier having the above-mentioned alkali metal preliminarily supported thereon. As the alkali metal, the above-mentioned alkali metal to be preliminarily supported on the carrier may also be used, but it is preferred to use cesium at least from the viewpoint of the performance of the catalyst thereby obtainable. The alkali metal may be supported on the carrier by impregnating the carrier with a solution of an alkali metal hydroxide or an alkali metal salt, and then evaporating and removing the solvent. As such an alkali metal salt, a halide, a nitrate, an acetate, a carbonate, a hydrogencarbonate or a sulfate may be mentioned. The alkali metal is usually supported on the carrier together with silver. However, it may be supported before or after having silver supported on the carrier. Further, in addition to silver and the alkali metal, other metal elements such as an alkaline earth metal, rhenium, tungsten and molybdenum, may be supported on the carrier.
Silver may be supported by means of impregnating the carrier with a solution wherein silver is dissolved in the form of a complex and then by heating the impregnated carrier to decompose the complex. As is well known, the complex of silver can easily be prepared by reacting a silver compound with an organic compound as a complex-forming reagent. The silver compound may be a compound which is decomposable at a temperature of at most 500xc2x0 C., preferably at most 300xc2x0 C., more preferably at most 260xc2x0 C., to deposit silver. As such a silver compound to be used for the formation of the complex, silver oxide, silver nitrate, silver carbonate, silver sulfate or various silver carboxylates such as silver oxalate, may, for example, be mentioned. Among them, silver oxalate is preferred, since the decomposition temperature is low.
The complex-forming compound may, for example, be ammonia, an amine compound or a compound having a carbonyl group or a carboxyl group. The amine compound may, for example, be a monoamine, a polyamine or an alkanolamine. The monoamine may, for example, be pyridine or an amine having from 1 to 6 carbon atoms. The polyamine may, for example, be ethylenediamine or 1,3-diaminopropane, and the alkanol amine may, for example, be ethanolamine. Among them, ethylenediamine and 1,3-diaminopropane are preferred from the viewpoint of the performance of the finally obtainable catalyst, and particularly preferred is a mixture of the two. Also, the compound having a carbonyl group may, for example, be acetylacetone, and the compound having a carboxyl group may, for example, be neodecanoic acid. As the solvent for the solution of a complex of silver with an organic compound, water is most preferred from the simplicity of the operation, but an aqueous solution having an alcohol added, or an organic solvent such as toluene, may also be used.
The method for impregnating the carrier with a solution having a complex of silver with an organic compound dissolved therein, may, for example, be a method of immersing the carrier in such a solution, or a method of spraying such a solution to the carrier.
The operation of heating the carrier impregnated with the complex of silver with the organic compound to decompose the complex and deposit silver, is carried out by contacting the impregnated carrier with a heated gas. The heating is carried out at a temperature of from 120 to 500xc2x0 C. until the content of the organic compound in the resulting catalyst becomes less than 0.1 wt %. It is preferred to carry out the heating until the content of the organic compound in the catalyst becomes less than 0.05 wt %, particularly preferably less than 0.02 wt %. As the gas for the heating, an inert gas such as nitrogen, helium, argon or superheated steam, or a mixture of such an inert gas with oxygen such as air, may be employed. It is preferred to carry out the heating at a temperature of from 120 to 300xc2x0 C., more preferably from 130 to 260xc2x0 C., by using superheated steam. It is considered that when superheated steam is employed as the gas for heating, the distribution of silver and the alkali metal supported in the resulting catalyst will be uniform.
The heating of the impregnated carrier is carried out by a method wherein the impregnated carrier is continuously passed through a heating apparatus, i.e. a method wherein the impregnated carrier is continuously supplied to a heating apparatus, and while transporting it continuously in the apparatus from the inlet to the outlet, it is contacted with the heated gas. As the heating apparatus, a rotary kiln or the like may be employed, but it is preferred to employ a gas flow band dryer wherein the object to be dried is put on a gas flow type endless belt and transported in the dryer, while the heated gas is passed through the object to be dried from an upper or lower direction of the belt. Such a gas flow band dryer is disclosed, for example, in xe2x80x9cChemical Engineering Handbook (5th edition)xe2x80x9d 1988, compiled by the Society of Chemical Engineers, Japan, and published by Maruzen Co., Ltd. on Mar. 18, 1988, p. 674-683.
The heated gas to be used for heating the impregnated carrier is recycled to increase the energy efficiency. Namely, the gas contacted to the impregnated carrier in the heating apparatus will be withdrawn from the drying apparatus, and introduced again into the drying apparatus after discharging a part of the withdrawn gas and, instead, supplementing a fresh heated gas from outside of the system, to suppress accumulation of the solvent or the complex-forming compound evolved from the impregnated carrier, or organic substances as the decomposition products of such solvent or complex-forming compound.
In the present invention, the heated gas is supplemented afresh from outside of the system in an amount of at least 10 m3 per kg of the impregnated carrier supplied to the heating apparatus. If the amount of the fresh heated gas supplemented to the heated gas circulating in the heating apparatus, is small, organic substances will remain from 0.1 to 0.3 wt % in the resulting catalyst. If such a catalyst is used for producing ethylene oxide by oxidizing ethylene, after being stored for a long period of time, the selectivity for ethylene oxide will be lower by a few percent than immediately after the production. The reason why from 0.1 to 0.3 wt % of organic substances will remain in the resulting catalyst if the amount of the fresh heated gas supplemented to the circulating gas, is small, seems that organic substances will accumulate in the circulating gas, and a part thereof will be again adsorbed on the catalyst. However, if, in accordance with the present invention, a fresh heated gas is supplemented in an amount of at least 10 m3, preferably at least 12 m3 (in this specification, the volume of the gas is under the atmosphere wherein the impregnated carrier is present, and is not the volume as calculated as a standard state), per kg of the impregnated catalyst supplied to the heating apparatus, the content of organic substances in the resulting catalyst can be made to be at most 0.1 wt %. This is probably caused by the fact that the concentration of organic substances in the circulating gas is maintained at a low level. If such a catalyst having a low content of organic substances, is used for the production of ethylene oxide after being stored for a long period of time, the decrease in the selectivity for ethylene oxide, is small. In a preferred embodiment of the present invention, the fresh heated gas is supplemented to the circulating gas so that the content of organic substances in the resulting catalyst will be at most 0.05 wt %, particularly preferably at most 0.02 wt %.
For example, in a case where the impregnated carrier is heated in the above-mentioned gas flow band dryer to produce a catalyst, it is common to employ a gas flow type belt on which the impregnated carrier is deposited and which has a width of at least 25 cm and a length of at least 1 m, and to supply the impregnated carrier in an amount of at least 15 kg per hour. In a case where the impregnated carrier is supplied to the heating apparatus in an amount of 15 kg per hour, the fresh heated gas to be supplemented, is required to be at least 150 m3, preferably at least 180 m3, per hour. Further, in such a case, if the amount of the fresh heated gas to be supplemented is set to be 150 m3/hr and 10% of the circulating gas is replaced by the fresh heated gas, the amount of gas to be passed through the deposited layer of the impregnated carrier on the gas flow type belt may be set to be 1,500 m3/hr, and 150 m3/hr thereof i.e. 10% thereof, may be discharged out of the apparatus, and to the remaining 1,350 m3/hr, 150 m3/hr of the fresh heated gas is supplemented, so that 1,500 m3/hr of the gas will be again passed through the deposited layer of the impregnated carrier on the gas flow type belt. In such a case, the linear velocity of the circulating gas passing though the deposited layer of the impregnated carrier will be about 1.7 m/sec. When superheated steam is employed as the heated gas, the gas linear velocity passing through the deposited layer of the impregnated carrier is preferably from 0.3 to 5 m/sec from the viewpoint of the performance of the resulting catalyst. Further, the time required for the heat treatment is usually from 1 minute to 3 hours, preferably from 3 to 30 minutes. Namely, it is preferred to adjust the amount of the impregnated carrier to be supplied to the apparatus, the temperature of the superheated steam, the flow rate, etc., so that the impregnated carrier will pass through the heating apparatus within this period of time.
As another method, heating of the impregnated carrier may be carried out in two stages i.e. in the first and later stages. In the first stage, the majority of organic substances in the impregnated carrier is removed, and in the later stage, the remaining organic substances will be reduced to a level of less than 0.1 wt % by a gas flow comprising the fresh heated gas as a main component. In such a case, in the first stage, the gas in the heating apparatus is circulated, so that the consumption of the energy required for the heating of the impregnated carrier is reduced. When the gas is circulated while it is contacted with the impregnated carrier, the gas temperature decreases, and various gases evolved from the impregnated carrier will accumulate in the circulating gas. Accordingly, it is common to a heating apparatus provided in the circulation path of the gas to heat the circulating gas, and discharge a part of the circulating gas out of the system, and instead, supplement a fresh heated gas, so that the temperature of the circulating gas will be maintained constant. In a case where accumulation of the gas generated from the impregnated carrier in a high concentration, is not problematic, the amount of the fresh heated gas to be supplemented, can be reduced.
The majority of the contained organic substances on the carrier is removed by the heating in the first stage, then the carrier is heated in the later stage until the content of organic substances will be less than 0.1 wt %. It is preferred to carry out the heating until the content of organic substances will be less than 0.05 wt %, more preferably less than 0.02 wt %. The heating in the later stage is carried out by a heated gas comprising the freshly supplemented gas as a main component, so as to avoid a possibility that the gas evolved from the impregnated carrier will be accumulated in the heated gas and will hinder the removal of organic substances from the impregnated carrier. Most simply, the later stage heating is carried out solely by the fresh heated gas without circulating the gas. In a case where circulation of the gas is carried out, at least 90% of the circulating gas is replaced with the fresh supplemented gas. For example, the interior of the above-mentioned gas flow band dryer is divided into a first stage heating zone and a later stage heating zone, so that a gas flow is controlled independently in each zone. In the first heating zone, circulation of the gas is carried out by discharging from 5 to 30% of the heated gas passed through the deposited layer of the impregnated carrier on the gas flow type belt and instead, supplementing the same amount of a fresh gas, and in the later heating zone, the heated gas passed through the deposited layer of the impregnated carrier may be discharge totally, or at least 90% thereof may be discharged out of the system and instead, supplementing the same amount of a fresh gas. The gas discharged from the later stage heating zone has a temperature not substantially lowered and does not substantially contain the gas evolved from the impregnated carrier. Accordingly, this gas may be supplied to the first stage drying zone. The later stage heating is carried out usually for at least 5 minutes. In order to save the consumption of energy in the later stage heating, the later stage heating is preferably within 20 minutes.
In the present invention, the analysis of the content of organic substances in the catalyst is carried out by a method (TG-DTA) wherein a thermogravimetric measurement (TG) and a differential thermal analysis (DTA) are used in combination.
The method for the TG-DTA measurement is disclosed in xe2x80x9cFourth Edition of Experimental Chemistry Course 4; Heatxe2x80xa2Pressurexe2x80x9d, compiled by the Chemical Society of Japan (1992), published by Maruzen Co., Ltd., on Feb. 5, 1992, p. 57-77. In the present invention, when the catalyst is subjected to the TG-DTA measurement in a stream of air, a heat generation and a weight loss which are considered to be attributable to combustion of organic substances contained in the catalyst and decomposition products thereof, are observed simultaneously during the period of an increasing temperature from about 225xc2x0 C. to 275xc2x0 C., and the content of organic substances in the catalyst is calculated from this weight loss. The catalyst obtained by the process of the present invention is useful as a catalyst for oxidation of an olefin, particularly for the production of ethylene oxide from ethylene. The production of ethylene oxide from ethylene by this catalyst, can be carried out by mean of a conventional method.
As a starting material gas for the reaction, a gas mixture comprising from 1 to 40 vol % of ethylene and from 1 to 20 vol % of oxygen, is employed, and a certain proportion, such as from 1 to 70 vol %, of a diluting agent such as methane or nitrogen gas, may usually be incorporated. As an oxygen source, air or industrial oxygen is used. Further, as a reaction modifier, e.g. a halogenated hydrocarbon may be added to the starting material gas in an amount of from about 0.1 to 50 vol ppm, whereby formation of hot spots in the catalyst can be prevented, and the performance, particularly the selectivity, of the catalyst can be substantially improved. The flow rate of the starting material gas for the reaction is usually from 1,000 to 10,000 hxe2x88x921 as calculated on a GHSV basis. Here, GHSV is defined by a gas flow rate at 0xc2x0 C. under atmospheric pressure, per unit volume of the catalyst. The reaction can be carried out under a pressure of from 0.1 to 4 MPa (from 0 to 39 kg/cm2G) at a temperature of from 180 to 350xc2x0 C., preferably from 200 to 300xc2x0 C.
Now, the present invention will be described in further detail with reference to Examples and Comparative Examples. However, it should be understood that the present invention is by no means restricted to such specific Examples. The contents of silver, cesium, lithium, sodium and barium in the catalysts used in Examples and Comparative Examples were measured by a chemical analysis. TG-DTA of the catalyst was performed with ca. 15 mg of a sample heated at a programmed temperature of 10xc2x0 C./h under air flow of 50 ml/min.

Olefin oxidation catalyst and process for its production


A strain-relief assembly for a field-installable fiber optic connector is disclosed, wherein the assembly includes a ferrule holder, an intermediate sleeve, and a crimp sleeve. The ferrule holder back section holds a buffered section of a fiber optic cable, while the ferrule holder front end holds a ferrule and a splice assembly. A stub fiber is held within the ferrule and the splice assembly so as to interface with a section of field optical fiber protruding from the buffered section. The intermediate sleeve engages and generally surrounds a portion of the ferrule holder back section and thus surrounds a portion of the buffered layer. An intermediate sleeve handler may be used to handle the intermediate sleeve and attached the intermediate sleeve to the ferrule holder back section. Stress-relief strands from the fiber optic cable are flared around the outer surface of the intermediate sleeve. A crimp sleeve is placed over the intermediate sleeve to hold the ends of the stress-relief strands in place. The crimp sleeve is then crimped, which fixes the strand ends in place and also fixes the intermediate sleeve in place on the ferrule back section.

1. Field of the Invention
The present invention relates generally to fiber optic cables, and in particular, to an assembly for providing strain-relief for field-installable connectors for fiber optic cables.
2. Technical Background
Optical fibers are widely used in a variety of applications, including the telecommunications industry in which optical fibers are employed in a number of telephony and data transmission applications. Due, at least in part, to the extremely wide bandwidth and the low noise operation provided by optical fibers, the use of optical fibers and the variety of applications in which optical fibers are used are continuing to increase. For example, optical fibers no longer serve as merely a medium for long distance signal transmission, but are being increasingly routed directly to the home or, in some instances, directly to a desk or other work location.
The ever increasing and varied use of optical fibers has spurred the use of field installable optical fiber connectors. Field installable optical fiber connectors are used to terminate the ends of optical fibers, and enable quicker connection and disconnection than fusion splicing. A typical connector holds the end of each optical fiber in a ferrule. The connector aligns the core of the two fibers so that light can pass between the fiber ends, and provides a mechanical coupling to hold the two fiber ends together. Connectors have traditionally been one of the main concerns in using fiber optic systems because they introduce loss and because different connector types were typically not compatible. While the use of connectors was once problematic, manufacturers have standardized and simplified them greatly. This increasing user-friendliness has contributed to the increase in the use of fiber optic systems.
Current field installable connectors are designed to be installed and strain relieved on fiber cables or fiber smaller than 2.9 mm. Common cable/fiber sizes are 900 μm tight-buffered fiber and 2.9 mm jacketed cable. A typical 2.9 mm jacketed cable consists of 900 μm tight-buffered fiber surrounded by aramid yarn and a thin walled jacket. A need exists for fiber optic cables having larger fiber optic cables. Unfortunately, installing field-installable connectors directly onto larger fiber optic cables is problematic given conventional connector designs. Therefore, a need exists for new fiber optic connectors adapted for larger fiber optic cables, as well as standard fiber optic cables that may comprise additional and/or alternative structures.

Strain-relief assemblies and methods for a field-installable fiber optic connector


The bucket elevator construction bolt comprises a flat head and a threaded shaft, the bolt further incorporating a collar adjacent the head, the collar including a plurality of elongate, radially arrayed spline teeth which engage within the material of the elevator belt, maintaining the bolt position against radial torque or vibratory forces applied thereto.

The present invention relates to a bolt for use in engaging buckets of a bucket elevator to a driven belt of the bucket elevator. More particularly, the bolt includes an oversized spline toothed collar portion, the collar portion maintaining the bolt positioned for attachment of a nut thereto by engagement of the spline teeth within the material of the belt.


An adjustable chair support supplement has a foam material main body which is surrounded with a fabric covering and provided with straps for selected securement to the back of a chaise lounge or similar support. A fabric support pocket may be added for supporting the covered foam body to the top of a chaise lounge. The covered foam member forms a padded layer which may be selectively secured with the strap to different parts of the chaise lounge back so as to adjust supplemental user support as desired.

The present invention generally concerns an improved chair support supplement and more specifically concerns an adjustable foam pillow which may be selectively secured on a chaise lounge or other primary support so as to adjustably supplement user support thereon.
It is generally well known to make use of various pillows of differing constructions (such as, including fabric covered foam bodies) to supplement user support, such as on a couch or chair. One group of normally small, but often bulky, pillow supplements are commonly referred to as throw pillows. On a couch or easy chair, such pillows are frequently wedged into a corner such as formed between the back and arm of the couch or chair. Then, the user's body is positioned relative both the primary support and the supplemental pillow.
In such arrangements, the throw pillow offers limited support. Additionally, a user often is frequently attempting to adjust the position of the pillow for the desired comfort.
Use of such a pillow is even more problematic and less beneficial if it is desired to support some portion of the back, or especially if it is desired to support the neck and head area. Additional difficulties encountered include the fact that the pillow itself is often positioned simply by being trapped between the user's body and the primary support. Hence, if the user moves, such as to get up from the chair or to readjust, the pillow often falls down or otherwise dislocates from the desired position.
In addition to the foregoing drawbacks, typical throw pillows, such as decorative or bulky pillows on a couch or easy chair, would not be usable in many other instances where some supplemental support is desired. For example, many kitchen chairs or other chairs at tables, have an unpadded, ladder back type construction, with which a bulky pillow could not be used. In such instances, it has been known to literally tie a pillow to the back of the chair, but such an arrangement, in general, offers no specific adjustability.
Still further problems may exist in other specific settings, such as outdoor use as may be encountered with a chaise lounge or similar. The entire disclosure (including all figures and specification description) of commonly assigned U.S. Pat. No. 5,010,610 to Ackley for "Multilayer Supplemental Support Pad" is hereby incorporated in this application by reference. The Ackley '610 patent discloses a multilayer supplemental support pad which is an ideal arrangement for supplementing the entire support surface of a chaise lounge or other similar primary support. However, such invention is not specifically intended to address providing an adjustable chair support supplement for supplementing support of a selected region of a user on a chaise lounge or other similar primary support.


An etching method, for etching a silicon nitride film on an underlying silicon oxide film by using a hard mask whose principal component is a silicon oxide, includes a step of etching the hard mask by using the resist film as a mask to form a mask pattern therein; a step of ashing the resist film; a step of oxidizing the hard mask; a main etching step of etching the silicon nitride film by using the patterned hard mask as a mask; and a step of overetching the silicon nitride film at a high selectivity of the silicon nitride film to the silicon oxide film. The main etching step is performed after the step of forming the mask pattern in the hard mask and before the overetching step at a selectivity of the silicon nitride film to the silicon oxide film smaller than that in the overetching step.

In order to develop high-integration semiconductor devices with a thinner film structure, the film's kind and structure has been variously studied, and, for example, new CMOS gate structures have been proposed. In a conventional CMOS gate structure, a gate insulating film is formed on a silicon film, and a thinning of the gate insulating film has been progressed. However, a leakage current increases as the gate insulating film becomes thinner, so that the conventional gate structure has a limitation to the thinning thereof.
As one of the new CMOS gate structures, there is, e.g., a so-called three-dimensional gate structure. In such a structure, it is required to form a gate electrode having a fine and three-dimensional shape. Further, in an aspect of a material, a metal gate electrode is under investigation instead of a conventional polycrystalline silicon electrode, and accordingly, considerably complex processes are required in a next-generation semiconductor device manufacturing process.
As one of the processes, a process for etching a silicon nitride (SiN) film on an underlying silicon oxide (SiO2) film has been studied. The patterned silicon nitride film formed by the etching is used in forming the gate electrode later.
However, in general, in case of etching a film, an etching rate of a substrate surface is not completely uniform, and it is difficult to make the etching rates of a central portion and a peripheral portion identical to each other. Accordingly, the etching is continued after the film is etched to expose an underlying film, which is called an overetching. Generally, in case of the overetching, it is required to ensure a high selectivity of the film to the underlying film, but the selectivity of the film to the underlying film is approximately 7 to 10 at most.
However, in a semiconductor device structure being considered herein, the silicon oxide film as the underlying film is very thin, e.g., 5 nm. In this case, a high selectivity of, e.g., about 20 to 40 is required to perform the overetching. Japanese Patent Laid-open Application No. 2003-229418 discloses a method for performing an etching by using, as an etching gas, a gaseous mixture containing CH3F gas and O2 gas wherein the mixing ratio (O2/CH3F) of the O2 gas to the CH3F gas is 4 to 9, in order to increase the selectivity of the silicon nitride film to the silicon oxide film when etching the silicon nitride film by using the silicon oxide film as a mask. Therefore, in the process for etching the silicon nitride film on the underlying silicon oxide film, by using the gaseous mixture upon the overetching, it is possible to etch the silicon nitride film while suppressing the reduction of the underlying film even though the underlying silicon oxide film is thin.
However, in case of using the aforementioned gaseous mixture, there occur problems as described below. FIG. 10A is a view showing a laminated body before etching the above-described silicon nitride film, and in FIG. 10A, reference numerals 11, 12, 13, 14 and 15 denote a silicon (Si) film, a silicon oxide film, a silicon nitride film, a nitrogen containing silicon oxide (SiON) film serving as a hard mask, a resist film and a resist pattern formed in the resist film 15, respectively. In case of performing a conventional etching on such laminated body, the SiON film 14 is etched by using the resist film 15 as a mask, the resist film 15 is removed by ashing, and an etching is then performed with the gaseous mixture described in Japanese Patent Laid-open Application No. 2003-229418 by using the SiON film 14 as a mask.
However, as described above, if an etching is performed by using a gas having a very high selectivity of the silicon nitride film 13 to the silicon oxide film 12, an etching action to the silicon nitride film 13 is strong. At this time, since the silicon nitride film 13 and the SiON film 14 serving as a hard mask have a similar material composition, the gaseous mixture causes local damage to the SiON film 14. Further, because the SiON film 14 is thin, e.g., 50 nm, and the SiON film 14 is not completely uniform even if it has an in-surface uniformity within a specification, holes 18 are formed in the SiON film 14 as confirmed by an experiment. If there occurs such a phenomenon wherein the holes 18 are formed (hereinafter referred to as "pitting"), a surface of the silicon nitride film 13 is damaged through the holes 18, which affects a next process.
It may be considered to protect the SiON film 14 without ashing the resist film 15 to remain when etching the silicon nitride film 13. However, because the gaseous mixture contains a large amount of oxygen, the resist film 15 is ashed when the silicon nitride film is etched. Therefore, in order to protect the SiON film 14, a film thickness of the resist film 15 has to be large. However, in that case, an etching profile is deteriorated. That is, in order to improve the etching profile, the resist film 15 is required to be thin. Under these circumstances, there is demanded an etching method capable of performing the above-described etching without damaging the silicon nitride film.
Further, Japanese Patent Laid-open Application No. 2000-269220 discloses, as a method for forming a hard mask of silicon nitride, a technology capable of thinning a silicon nitride layer by oxidizing an antireflection film on a silicon nitride layer by using an oxygen plasma generated when a resist mask located on the antireflection film is ashed to thereby use the oxidized antireflection film as a protection layer. However, the technology cannot achieve the object of the present invention.

Etching method and apparatus, computer program and computer readable storage medium


An apparatus for dewatering slurry utilizes a vertical skeletal retainer framework, having a top end and a bottom end, into which rigid filter plates, a geotextile filter bag, and/or other filter is installed. The vertical orientation employs gravity to induce maximum drainage, with water in the slurry filtering through the plates or bag and falling downwardly. At the bottom end of the framework, doors or gates facilitate selective holding, and emptying of, dewatered solids. A support structure permits a transport vehicle or hopper to be positioned under the framework for collection and removal of dewatered solids. After removal of its contents, the bag can be pressure washed from the outside and potentially reused. The apparatus may be portable, with the framework being pivotable on a wheeled base.

In agriculture, mining, and other industries, there are a wide variety of slurries in need of dewatering. One context is the dewatering of swine, dairy, or beef cattle waste. In confined space, hog, dairy, or beef production, the manure and waste is often collected directly under the barn area. The floors of the barn are slotted, allowing the waste material to accumulate under the barn. This material is diluted by wash water and other liquids and finally is removed by pumping or draining. The waste material is either sent to a lagoon storage area or in many cases used as a fertilizer. The accumulated slurry can be pumped into a tanker truck or wagon and taken to farm fields and applied as liquid manure. Application of this material as a liquid, though, has a number of disadvantages, including environmental damage due to runoff of the liquid into adjacent waterways or ditches. Odor from the liquid manure cause issues with adjacent land owners. Dewatering the waste reduces these liabilities and also reduces the number of trips across the farm fields, reducing soil compaction and lowering fuel costs.
In food processing, slurries are created that contain large amounts of solids which must be removed before the water can be either reused in the process or sent to a waste water treatment facility. Many times these slurries contain solids in need of separation and dewatering, such as potato peelings or grit from the washing processes. In the coal mining process, fine particles of coal are lost in the washing process and must be settled out in large holding ponds. This material can be captured with a proper dewatering process and the coal then reclaimed for sale. In municipal waste water treatment plants, solids are accumulated in digesters. Eventually this slurry must be removed from the digester and dewatered. In the sand and gravel industry the washing process many times produces a slurry stream that contains large amounts of small aggregate material that could be reclaimed by the proper apparatus.
There are many different types of dewatering apparatuses in use today. Many of these are mechanical in nature and require a large amount of energy to operate and specialized skills to maintain. One example is disclosed in Heywood's "Apparatus for Treating Sewage," U.S. Pat. No. 392,607. Another is disclosed in U.S. Pat. No. 3,970,552, "Method and Means for Separation of Liquids from a Mixture of Solids and Liquids," to Bongert.
Other examples of mechanical dewatering equipment for accomplishing high volume dewatering of liquid slurries include the following: U.S. Pat. No. 4,116,838, "Sludge Filter," to Lazzarotto; U.S. Pat. No. 4,929,353, "Portable Liquid-Solid Separator for Bulk Sludge," to Harris; U.S. Pat. No. 5,156,749, "Dewatering System for Sludge Removal," to Williams; U.S. Pat. No. 5,589,081, "Divided Phase Separator for Liquid/Solid Separation in Sludge" to Harris; U.S. Pat. No. 5,595,654, "Sludge Filtration System and Method," to Caughman, Jr.; and U.S. Pat. No. 4,871,454, "Portable Dumpster Slurry Separating System," to Lott. Such systems may utilize a type of filter, but have mechanical disadvantages and often require tilting of sludge.
Another example is U.S. Pat. No. 4,133,769, "Liquid Filter Having Self-Retaining Filter Bag," to Morgan, Jr., incorporating a filter bag suspended inside a shell. This device has a major disadvantage in that the dewatered material must be lifted out of the device to dispose or reprocess, limiting the amount of material that can be effectively dewatered due to the weight of the dewatered material. A similar example of is U.S. Pat. No. 5,287,985, "Container for Dewatering or Packaging and Transportation," to Hatayama. This device has the considerable drawback in that the volume of dewatered material would have to be limited to the weight limitations of the device. Most dewatering processes require large volume and weight capabilities.
Large geotextile bags have been used successfully in dewatering many different types of slurries. Such fabric filter bags are sewn in cylindrical shapes in sizes from six feet in circumference and twelve feet in length to ninety feet in circumference with a length of three hundred 300 feet. Slurry is treated with a flocculent and pumped into the bags, where the solids are captured, and the liquid "bleeds" through the filtration fabric. After the contents have been allowed to dry for various time periods, ranging from a few days to months or even years, the bag is cut open, and the contents are removed. One example of this type of device is found in U.S. Pat. No. 6,186,701, "Elongate Flexible Container," to Kempers.
A further example of existing technology is found in U.S. Pat. No. 7,112,283, "Method and System for Processing Waste," to Stephens. This type of slurry dewatering has disadvantages including the handling expense of the consolidated solids and the fact that the required bags must be laid on the ground and subjected to weather-related and drainage issues. In addition, the positioning of the bag on the ground tends to bind the bottom of the bag, which is where the liquid is most likely to drain out. This will cause the liquid to pool inside the bag and increase the drying time required to accomplish the dewatering phase.

This patent is subject to a terminal disclaimer.

Apparatus for dewatering solids-laden liquids


A moving image coding method that can prevent playback discontinuity without an increase in processing load during playback is provided.

The following describes a DVD-Video disc (hereafter simply referred to as a "DVD") as a conventional technique.
FIG. 1 shows a structure of a DVD. As shown in the lower part of FIG. 1, a logical address space is provided between a lead-in area and a lead-out area on a DVD disc. Volume information of a file system is stored at the start of the logical address space, followed by application data such as video and audio.
The file system is defined by ISO 9660 or Universal Disc Format (UDF), and is a mechanism for representing data on a disc in units called a directory and a file. A personal computer (PC) for daily use, too, can present data stored on a hard disk in the form of directories and files, through a file system such as FAT or NTFS. This enhances usability.
DVDs use both UDF and ISO 9660 (a combination of which is known as "UDF Bridge"), so that data can be read by a file system driver of any of UDF and ISO 9660. In the case of DVD-RAM/R/RW which are rewritable DVD discs, data can be physically read, written, and deleted through these file systems.
Data recorded on the DVD can be viewed, through UDF Bridge, as directories and files as shown in the upper left part of FIG. 1. A directory called "VIDEO_TS" is placed immediately below a root directory ("ROOT" in FIG. 1). The application data of the DVD is stored in this VIDEO_TS directory. The application data is stored as a plurality of files. The plurality of files mainly include the following:
VIDEO_TS.IFO disc playback control information file
VTS—01—0.IFO video title set#1 playback control information file
VTS—01—0.VOB video title set#1 stream file
. . .
Two types of extensions are specified. "IFO" indicates a file storing playback control information, and "VOB" indicates a file storing an MPEG stream that is AV data. Playback control information includes information for realizing interactivity (a technique of dynamically changing playback in accordance with a user operation) employed for DVDs, information such as metadata that is attached to a title or an AV stream, and the like. In DVDs, playback control information is also referred to as navigation information.
Playback control information files include "VIDEO_TS.IFO" for managing the entire disc, and "VTS—01—0.IFO" that is playback control information for an individual video title set (in DVDs, a plurality of titles, e.g., different movies or different versions of a movie, can be recorded on a single disc). "01" in the body of the file name "VTS—01—0.IFO" indicates a number of the video title set. For example, a playback control information file for video title set#2 is "VTS—02—0.IFO".
The upper right part of FIG. 1 shows a DVD navigation space in an application layer of the DVD. This is a logical structure space where the aforementioned playback control information is developed. In the DVD navigation space, the information stored in "VIDEO_TS.IFO" is developed as video manager information (VMGI), and the playback control information that exists for each individual video title set, such as "VTS—01—0.IFO", is developed as video title set information (VTSI).
The VTSI includes program chain information (PGCI). The PGCI is information about a playback sequence called a program chain (PGC). The PGCI is mainly composed of a group of cells and a kind of programming information called commands. A cell itself corresponds to all or part of a video object (which is an MPEG stream and is abbreviated as VOB). Playing a cell is an equivalent of playing a section, in a VOB, that is designated by the cell.
Commands are processed by a DVD virtual machine, and are similar to, for example, Java (registered trademark) Script executed on a browser. However, DVD commands differ from Java (registered trademark) Script in the following point. Java (registered trademark) Script controls windows and browsers (e.g. open a window of a new browser), in addition to performing logical operations. On the other hand, DVD commands only control playback of AV titles, such as by designating a chapter to be played, in addition to performing logical operations.
A cell includes start and end addresses of a corresponding section in a VOB recorded on the disc (logical storage addresses on the disc), as its internal information. A player reads data using the start and end addresses written in the cell with regard to the VOB, and plays the read data.
FIG. 2 is a schematic view for explaining navigation information that is embedded in an AV stream. Interactivity, which is featured by DVDs, is realized not only by navigation information stored in the aforementioned "VIDEO_TS.IFO" and "VTS—01—0.IFO". Other important navigation information is multiplexed in a VOB together with video and audio data, by using a dedicated carrier called a navigation pack (hereafter referred to as a navi pack or NV_PCK).
A menu is explained below as a simple example of interactivity. A menu screen has several buttons. For each of the buttons, a process to be performed when the button is selected and executed is defined. One button is in a selected state on the menu (the selected button is highlighted by being overlaid with a semitransparent color, to indicate the selected state of the button to a user). The user can move the highlight to any of buttons located above, below, right, and left of the currently selected button, by using Up/Down/Right/Left keys on a remote control. When the user moves the highlight to a button which the user wants to select for execution using the Up/Down/Right/Left keys on the remote control and determines the selection (e.g. by pressing an Enter key), a program of a command corresponding to the selected button is executed. Typically, playback of a title or a chapter corresponding to the selected button is executed by the command.
The upper left part of FIG. 2 roughly shows control information stored in the NV_PCK.
The NV_PCK includes highlight color information, button information for each individual button, and the like. The highlight color information includes color palette information, which specifies the semitransparent highlight color to be overlay-displayed. The button information for each individual button includes rectangular area information showing a position of the button, highlight movement information about movements from the button to other buttons (designating move destination buttons corresponding to the user's operations of the Up/Down/Right/Left keys), and button command information (a command to be executed when the selection of the button is determined).
The highlight on the menu is generated as an overlay image, as shown in the upper middle right part of FIG. 2. This overlay image is obtained by giving the color specified by the color palette information to the area shown by the rectangular area information of the button information. The overlay image is superimposed on a background image shown in the right part of FIG. 2, and the resulting image is displayed on the screen.
In this way, menus in DVDs are realized. A main reason why part of navigation data is embedded in the stream using the NV_PCK is to allow menu information to be dynamically updated in synchronization with the stream (e.g. displaying a menu only for five to ten minutes during movie playback), so that even an application that has a difficult synchronization timing can be appropriately realized. Another main reason is to improve user operability by, for example, storing information for supporting special playback in the NV_PCK so as to enable AV data to be smoothly decoded and played even when a DVD is played in a special mode such as fast-forward or rewind.
FIG. 3 is a conceptual view showing a VOB that is a stream on the DVD. As shown in FIG. 3, data such as video, audio, and subtitles (shown in the level A in FIG. 3) are packetized and packed (shown in the level B in FIG. 3) and multiplexed with each other to form one MPEG program stream (shown in the level C in FIG. 3), based on the MPEG system standard (International Organization for Standardization/International Electrotechnical Commission (ISO/IEC) 13818-1). A NV_PCK that carries a button command for realizing interactivity is multiplexed in the MPEG program stream too, as described above.
In the MPEG system, multiplexing has the following characteristic. While individual data to be multiplexed, i.e., video data, audio data, or subtitle data, is arranged in a bit string based on a decoding order, these different types of data on the whole, i.e., video data, audio data, and subtitle data altogether, are not necessarily arranged in a bit string based on a playback order. This is because a decoder model for a multiplexed MPEG system stream (generally called a System Target Decoder or an STD (shown in the level D in FIG. 3)) has decoder buffers corresponding to individual elementary streams obtained by demultiplexing, and temporarily stores demultiplexed data in the corresponding decoder buffers until decoding. For instance, decoder buffers defined by DVD-Video have different sizes depending on individual elementary streams, such that a buffer size is 232 KB for video, 4 KB for audio, and 52 KB for subtitles.
In other words, subtitle data multiplexed adjacent to video data is not necessarily decoded and played at a same timing as the video data.
There is also a next-generation DVD standard called a blu-ray disc (BD).
While DVDs are intended for package distribution of video (DVD-Video format) of a standard image quality (Standard Definition quality) and recording of analog broadcasting (DVD Video Recording format), BDs are capable of recording digital broadcasting of a high definition image quality (High Definition quality) as it is (Blu-ray Disc Rewritable format, hereafter referred to as BD-RE).
However, since BD-RE is widely intended for recording of digital broadcasting, special playback supporting information and the like have not been optimized. For future package distribution of high-resolution video at a higher rate than digital broadcasting (BD-ROM format), a mechanism that does not cause any stress on the user even during special playback is needed.
MPEG-4 Advanced Video Coding (AVC) has been employed as one of the moving image coding methods in BDs. MPEG-4 AVC is a next-generation coding standard with a high compression rate, which was jointly developed by ISO/IEC JTC1/SC29/WG11 and International Telecommunication Union—Telecommunication Standardization Sector (ITU-T).
In general, when coding a moving image, information is compressed by reducing redundancies in a temporal direction and a spatial direction. In inter-picture prediction coding that aims to reduce temporal redundancies, motion detection and generation of a predictive image are performed in units of blocks with reference to a picture which precedes and/or follows a coding target picture, and a difference between the coding target picture and the generated predictive image is coded. The term "picture" used here denotes an image of one screen. In detail, a picture denotes a frame in a progressive format, and a frame or a field in an interlaced format. In the interlaced format, one frame is made up of two fields of different times. An interlaced image can be coded and decoded by processing one frame as the frame itself, processing one frame as two fields, or processing each block of a frame as a frame structure or a field structure.
An I picture is an intra-picture prediction coded picture that has no reference image. A P picture is an inter-picture prediction coded picture that references only one picture. A B picture is an inter-picture prediction coded picture that references two pictures simultaneously. A B picture can reference any combination of two pictures that precede and/or follow the B picture in terms of display time. A reference image (reference picture) can be designated for each block that is a basic unit of coding/decoding. Here, a reference picture that is written first in a coded bit stream and a reference picture that is written later in the coded bit stream are distinguished from each other as a first reference picture and a second reference picture, respectively. Note here that, to code/decode a P picture or a B picture, its reference picture needs to have been already coded/decoded.
A residual signal that is obtained by subtracting a predictive signal generated by intra-picture prediction or inter-picture prediction from a coding target image is frequency-transformed and quantized, and then variable length coded and outputted as a coded stream. MPEG-4 AVC has two variable length coding methods, namely, context-adaptive variable length coding (CAVLC) and context-adaptive binary arithmetic coding (CABAC), that can be switched in units of pictures. The context adaptive referred to here denotes a mode of adaptively selecting an efficient coding method in accordance with circumstances.
The following describes a stream in which different coding methods (or a moving image with different attributes) can exist, and a decoding process by a decoding device that receives such a stream. Two examples are used in this specification. A first example is a case where different variable length coding methods (CAVLC/CABAC) can exist. A second example is a case where a luminance level threshold which is used when performing a transparency process by a luminance key on a picture-in-picture can take different values.
Firstly, the first example of stream in which different coding methods (or a moving image with different attributes) can exist, that is, the example where different variable length coding methods (CAVLC/CABAC) can exist, is described below. FIG. 4 shows an example of variable length coding that is applied to pictures which constitute a randomly accessible unit in an MPEG-4 AVC stream. In MPEG-4 AVC, there is no concept corresponding to a group of pictures (GOP) of MPEG-2 Video. However, by dividing data by a special unit of pictures that is able to be decoded independently of other pictures, a randomly accessible unit corresponding to a GOP can be obtained. Such a randomly accessible unit is hereafter called a random access unit (RAU). As shown in FIG. 4, whether CABAC or CAVLC is used for variable length coding is determined on a picture basis.
A variable length decoding process is different between CABAC and CAVLC. The variable length decoding process for each of CABAC and CAVLC is described below, with reference to FIGS. 5A to 5C. FIG. 5A is a block diagram of an image decoding device that performs context-adaptive binary arithmetic decoding (CABAD) as a process of decoding data which is variable length coded according to CABAC, and context-adaptive variable length decoding (CAVLD) as a process of decoding data which is variable length coded according to CAVLC.
An image decoding process according to CABAD is carried out in the following manner. Firstly, coded data Vin generated according to CABAC is inputted to a stream buffer 5001. An arithmetic decoding unit 5002 reads coded data Vr from the stream buffer 5001, performs arithmetic decoding on coded data Vr, and inputs binary data Bin1 to a binary data buffer 5003. A binary data decoding unit 5004 acquires binary data Bin2 from the binary data buffer 5003, decodes binary data Bin2, and inputs binary data Din1 obtained as a result of the decoding to a pixel reconstruction unit 5005. The pixel reconstruction unit 5005 performs processes such as inverse quantization, inverse transformation, and motion compensation on binary decoded data Din1 to reconstruct pixels, and outputs decoded data Vout. FIG. 5B is a flowchart showing an operation from the start of decoding CABAC coded data to the pixel reconstruction process. Firstly, in Step S5001, CABAC coded data Vin is arithmetic-decoded to generate binary data. Next, in Step S5002, a judgment is performed as to whether or not a predetermined unit of binary data, such as one or more pictures, has been obtained. When the predetermined unit of binary data has been obtained, the operation proceeds to Step S5003. When the predetermined unit of binary data has not been obtained, Step S5001 is repeated. This binary data buffering is performed for the following reason. In CABAC, an amount of code of binary data per picture or per macroblock may increase greatly, which can cause a significant increase in processing load for arithmetic decoding. Therefore, to realize seamless playback even in a worst case, it is necessary to conduct a certain amount of arithmetic decoding in advance. In Step S5003, the binary data is decoded. In Step S5004, the pixel reconstruction process is performed on the decoded binary data. Thus, in CABAD, the pixel reconstruction process cannot be started until the predetermined unit of binary data is obtained in Steps S5001 and S5002. This causes a delay in decoding start.
An image decoding process according to CAVLD is carried out in the following manner. Firstly, coded data Vin generated according to CAVLC is inputted to the stream buffer 5001. Next, a CAVLD unit 5006 performs variable length decoding on coded data Vr, and outputs VLD decoded data Din2 to the pixel reconstruction unit 5005. The pixel reconstruction unit 5005 performs processes such as inverse quantization, inverse transformation, and motion compensation on VLD decoded data Din2 to reconstruct pixels, and outputs decoded data Vout. FIG. 5C is a flowchart showing an operation from the start of decoding CAVLC coded data to the pixel reconstruction process. Firstly, in Step S5005, CAVLD is performed. Next, in Step S5004, the pixel reconstruction process is performed. Thus, CAVLD differs from CABAD in that there is no need to wait until the predetermined unit of data is obtained before starting the pixel reconstruction process, and there is no need to have an intermediate buffer in the variable length decoding process such as the binary data buffer 5003.
FIG. 6 is a flowchart showing an operation of a conventional decoding device that decodes a stream in which the variable length coding method is switched as in the example of FIG. 4. It should be noted that, in this specification, a decoding device and a decoding method are examples of a moving image playback device and a moving image playback method, respectively.
Firstly, in Step S5101, the decoding device acquires information showing a variable length coding method applied to a picture, and proceeds to Step S5102. In Step S5102, the decoding device judges whether or not the variable length coding method of the current picture is different from a variable length coding method of a picture immediately preceding the current picture in a decoding order. Since CABAD and CAVLD use different buffer management methods in variable length decoding, when the variable length coding method is different, the decoding device proceeds to Step S5103 to switch the buffer management. When the variable length coding method is not different, the decoding device proceeds to Step S5104. In Step S5104, the decoding device judges whether or not the variable length coding method of the current picture is CAVLC. When the variable length coding method of the current picture is CAVLC, the decoding device proceeds to Step S5105 to perform CAVLD. When the variable length coding method of the current picture is CABAC, the decoding device proceeds to Step S5106. In Step S5106, the decoding device judges whether or not the variable length coding method of the current picture is different from the variable length coding method of the immediately preceding picture in the decoding order. When the variable length coding method of the current picture is different, the decoding device proceeds to Step S5107. In Step S5107, the decoding device performs arithmetic decoding until the predetermined unit of binary data is obtained as shown in Steps S5001 and S5002 in FIG. 5, and then decodes the binary data. When the variable length coding method of the current picture is not different in Step S5106, the decoding device proceeds to Step S5108 to perform a normal CABAD process. The normal CABAD process mentioned here is a CABAD process that omits the binary data buffering which is necessary when CAVLC is switched to CABAC or when decoding of a CABAC coded stream begins. Lastly, in Step S5109, the decoding device performs the pixel reconstruction process.
The second example of stream in which different coding methods (or a moving image with different attributes) can exist, that is, the example where a luminance level threshold (i.e. a moving image attribute) which is used when performing a transparency process by a luminance key on a picture-in-picture can take different values, is described next. Package media such as a BD-ROM provide an application for displaying video other than main video, e.g. the director's commentary video, by overlaying it on the main video. Such an application is referred to as picture-in-picture. FIG. 7 is a diagram for explaining this picture-in-picture. FIG. 7(a) shows image display planes, where plane 2 is to be overlaid on plane 1. FIGS. 7(b) and 7(c) show images displayed on plane 1 and plane 2, respectively. The display image of plane 2 is overlay-displayed on the display image of plane 1 (FIG. 7(d)). In such a picture-in-picture, the image displayed on plane 1 is the main video, and the image displayed on plane 2 is the video other than the main video. Simply overlaying the display video of plane 2 on plane 1 causes the image of plane 1 to be completely hidden. To prevent this, a transparency process by a luminance key is applied to the image of plane 2. The following describes the transparency process by the luminance key. In the transparency process, each pixel in an image is displayed transparent or nontransparent depending on a luminance level of the pixel. In detail, the transparency process is as follows.
(1) When the luminance level is in a range of 0 to predetermined threshold YL inclusive, the pixel is displayed completely transparent (with a transparency rate of 1).
(2) When the luminance level exceeds predetermined threshold YL, the pixel is displayed nontransparent, at the luminance level (with a transparency rate of 0).
In FIG. 7(c), suppose the luminance level is equal to or smaller than predetermined threshold YL in the diagonally shaded area and exceeds predetermined threshold YL in the other area. In such a case, when overlaying the image of plane 2 on plane 1, the diagonally shaded area is displayed transparent while the other area is displayed nontransparent, as shown in FIG. 7(d). Which is to say, in the image of plane 2, only an area (pixel) whose luminance level exceeds threshold YL is overlay-displayed on the image of plane 1. Thus, plane 2 is separated into a foreground and a background according to the luminance level threshold and only the foreground is overlay-displayed on plane 1, thereby realizing a picture-in-picture.    Patent Reference 1: Japanese Unexamined Patent Application No. 2000-228656 Publication    Non Patent Reference 1: Proposed SMPTE Standard for Television: VC-1 Compressed Video Bitstream Format and Decoding Process, Final Committee Draft 1 Revision 6, 2005.7.13.

Moving image coding method, moving image coding device, moving image recording method, recording medium, moving image playback method, moving image playback device, and moving image playback system

Abstract: The moving image coding method codes a video stream that includes a first moving image and a second moving image to be overlaid on the first moving image. The moving image coding method includes: a step of determining a continuous playback section that is a group of partial sections and is subject to continuous playback, in the video stream (S5301 to S5303); a step of coding the first and second moving images in the partial sections constituting the continuous playback section, under a constraint that prevents a threshold from being changed in the continuous playback section, the threshold being used for a transparency process by a luminance key in the overlaying (S5304); and a step of generating management information including flag information which indicates that the threshold is fixed in the continuous playback section (S5305).


A holding dock for portable computers to house a portable computer and disperse heat includes an upper lid, a holding surface, sidewalls and a hub to form a heat dissipation space. Heated air generated by the computer may enter the heat dissipation space through a heat dissipation section formed on the holding surface. The hub has a fan mounted thereon to draw the heated air to provide heat dissipation effect for the portable computer. The hub further can connect other electronic devices to the portable computer. The heat dissipation space can also house the portable computer to facilitate carrying and storing.

The popularity of portable computers has risen dramatically during recent years. They may be compact but are equipped with almost the same facilities as regular desktop computers. Hence heat the dissipation space has to be reduced, which in turn also reduces dispersion which is generally not as efficient as desktop computers. Usage over a short period of time might not result in overheating; however prolonged use on a fixed spot with no way for thermal energy to effectively escape can cause the computer to shutdown (self protection). Frequent occurrence shortens the service life of a portable computer.
ROC patent publication No. 562177 entitled "Heat dissipation base dock for portable computers" discloses a technique which uses an aluminum plate with good conducting properties. The aluminum plate has a front end bent downwards to form an inclined angle for the plate surface so that a heat dissipation space is formed thereunder. The plate surface has heat dissipation vents. A fan is located thereunder so that when the portable computer is rested on the aluminum plate for use, the aluminum plate absorbs heat, and the fan generates cool air to carry away the thermal energy to achieve heat dissipation. While providing a means for heat dissipation in the portable computer, the aluminum plate is too bulky and inconvenient to carry. It also cannot be connected to other electronic equipment. There is still room for improvement.


An image signal recording operation control device is provided in a still video camera. The control device has a photographing optical system by which an image is formed on an electro-developing recording medium, by which the image is electronically developed. The control device also has a scanner optical system by which the image developed by the electro-developing recording medium is formed on a sensor imaging plane. A line sensor is provided for scanning on the sensor imaging plane to read out the image. When the electro-developing recording medium is not mounted in the still video camera, i.e., when an aerial image formed by the photographing optical system is read by the line sensor, the scanner optical system is displaced by a predetermined amount along the optical axis, in comparison with a state in which the electro-developing recording medium is mounted, so that the scanner optical system can form an in-focus image on the sensor imaging plane.

1. Field of the Invention
The present invention relates to a device which keeps a visible image, corresponding to an optical image obtained through a photographing lens, on a recording medium and which can read the visible image from the recording medium.
2. Description of the Related Art
Conventionally, silver halide photographic material is generally used as a material for recording an optical image. Silver halide photographic material has high optical sensitivity and high resolution, and the economical efficiency thereof is excellent. However, silver halide photographic material has drawbacks in that not only is the developing process cumbersome but also a visible image cannot be obtained at the same time that the photograph is taken. A dry-type developing method has been developed to simplify the developing process. However, simultaneous development in which a visible image is obtained upon photography is impossible in the dry-type developing method.
On the other hand, as non-silver-halide photographic materials, there are known electrophotographic materials, diazo type photographic materials, free-radical photographic materials and so on. In these materials, however, there is no material which has advantageous characteristics like silver halide photographic material, while being able to simultaneously develop and keep a visible image. Note that, electrophotographic materials have been used mainly in copying machines, since they can perform dry-type development and can simultaneously develop an electrostatic latent image, which is obtained by exposure, using toner.
In such electrophotographic materials, recently, a photographic material has been developed in which a recording medium made of the photographic material is electronically and directly developed similarly to a silver halide photographic material, so that the developed visible image can be immediately seen or recorded. Such a recording medium in which a visible image is electronically developed is referred to as an electro-developing recording medium in this specification.
Japanese Unexamined Patent Publication No. 5-2280, for example, discloses a recording medium which is a combination of an electrostatic information recording medium and an electric charge keeping medium, the electrostatic information recording medium having a photoconducting layer and an inorganic oxide material layer, and the electric charge keeping medium having a liquid crystal display. In this structure, when the electrostatic information recording medium is exposed while an electric voltage is applied to the electrostatic information recording medium and the electric charge keeping medium, electric charge in accordance with the amount of incident light is generated in the electrostatic information recording medium. Since the intensity of electric field applied to the liquid crystal display facing the electrostatic information recording medium is varied in accordance with the generated electric charge, an image corresponding to the amount of light distribution is indicated or developed on the liquid crystal display.
Japanese Unexamined Patent Publication No. 5-150251 discloses a dispersion type liquid crystal display in which an image indicated on the liquid crystal display is kept even if the electric field applied to the liquid crystal display is removed.
On the other hand, there is known a camera by which an image obtained by a photographing lens is formed on a plane in space as an aerial image, which is then formed onto an optical sensor through a scanner optical system to record the image on a recording medium.
The camera may be designed in such a manner that the electro-developing recording medium can be mounted, and the image developed by the electro-developing recording medium, or the aerial image can be recorded. However, since the electro-developing recording medium has sheets of glass for confining liquid crystal elements therein, the image position formed by the photographing optical system is changed depending upon whether or not the electro-developing recording medium is present, and thus the focusing position of the scanner optical system changes so that an in-focus image can not be formed on an optical sensor.
Further, when the image developed on the liquid crystal display is sensed by an optical sensor such as a line sensor, a light source is placed on one side of the liquid crystal display and the line sensor is placed on the other side of the liquid crystal display, and thus, a light beam, which is outputted by the light source and passes through the liquid crystal display, is read by the scanner optical system and the line sensor. Namely, the light source is provided on the optical axis of the scanner optical system. However, if the light source is positioned close to the electro-developing recording medium in a photographing operation, an eclipse (or vignetting) occurs on the recording medium, and thus the amount of light exposed onto the recording medium may be insufficient.
Furthermore, in such a structure, when the light source is located in a portion between the photographing optical system and the electro-developing recording medium, the back focus of the photographing optical system cannot be sufficiently short, since the space that the portion occupies must be large enough to dispose or accommodate the light source so that the degree of freedom of the design of the photographing optical system is low.

Device for controlling image signal recording operation


A seat assembly for a motorcycle that includes a frame. The seat assembly includes a seat cushion, a seat pan coupled to the seat cushion, and a front mount that extends from a forward portion of the seat pan. A rear mount extends from a rearward portion of the seat pan and a central mounting portion is located on the seat pan between the front and rear mounts. The central mounting portion defines a frame mount that latches to the frame when the seat assembly is in a first position with respect to the frame, and that releases from the frame when the seat assembly is in a second position with respect to the frame.

Motorcycles are provided with various types of seats for the comfort of motorcycle operators and passengers. Motorcycle seats can be coupled to the motorcycle in a variety of ways, including hinging the seat to the motorcycle frame, or bolting the motorcycle seat to the frame. Other motorcycle seats may be provided with hidden storage compartments, and may be coupled to the motorcycle using a keyed lock.

Mounting configuration and method for a motorcycle seat

Harley-Davidson Motor Company Group, Inc.


A method and apparatus for transmitting/receiving a Voice over Internet Protocol (VoIP) packet on a radio link in a mobile communication system which provides a voice service over a packet network connected to the Internet. To transmit a VoIP packet, a VoIP packet comprising a user datagram protocol (UDP) checksum field is received, the UDP checksum field is eliminated from the received VoIP packet, a cyclic redundancy check (CRC) is added to the UDP checksum field-free VoIP packet, for error detection in the radio link, and the VoIP packet having the CRC is transmitted on the radio link.

1. Field of the Invention
The present invention relates generally to a mobile communication system that interacts with the Internet. In particular, the present invention relates to a method and apparatus for efficiently processing a User Datagram Protocol (UDP) Checksum field when a UDP packet is transmitted on a radio channel.
2. Description of the Related Art
Today's mobile communication technology has evolved from a traditional voice service into a high-speed, high-quality wireless data packet communication system. A 3rd generation mobile communication system such as a Universal Mobile Telecommunication Service (UMTS) is based on Global System for Mobile communication (GSM) and General Packet Radio Services (GPRS). It provides a uniform service that transmits packetized text, digital audio and video, and multimedia data at a 2 Mbps or higher rate to mobile subscribers or computer users around the world. With the introduction of the concept of packet-switched access using a packet protocol like Internet Protocol (IP), UMTS allows access to any end point in a network at any time.
The 3rd Generation Partnership Project (3GPP), in charge of standardizing the UMTS communication system, has discussed support for Voice over Internet Protocol (VoIP) communications. VoIP is a communication technique in which a voice frame generated from a CODEC (Coder-Decoder) is converted to an IP/User Datagram Protocol (UDP)/Realtime Transport Protocol (RTP) packet, for transmission. Thus, VoIP provides a voice service over a packet network.
FIG. 1 illustrates the configuration of a VoIP-enabled User Equipment (UE) in a conventional mobile communication system.
Referring to FIG. 1, a VoIP-enabled UE 100 comprises a CODEC 106 for converting human voice to a voice frame, an IP/UDP/RTP layer 105 for converting the voice frame to an IP/UDP/RTP packet, a Packet Data Convergence Protocol (PDCP) layer 104 for compressing the header of the IP/UDP/RTP packet, a Radio Link Control (RLC) layer 103 for converting the IP/UDP/RTP packet to a form suitable for transmission on a radio channel, a Medium Access Control (MAC) layer 102, and a Physical PHY layer 101 for transmitting the packet data on the radio channel.
The voice packet data from the UE 100 is delivered to a Radio Network Controller (RNC) 120 via a Node B 110. Like the UE 100, the RNC 120 has a MAC layer 122, a RLC layer 123, and a PDCP layer 124. The RNC 120 converts the received data to the original IP/UDP/RTP packet and transmits it to a Core Network (CN) 130. The IP/UDP/RTP packet is transmitted to the other party over an IP network 140. The UE of the other party processes the voice data in the reverse order of the above-described operation and provides the voice data to the other party.
Now, a description is made of the functionalities of the RLC layer.
Typically, the RLC layer operates in one of three ways: unacknowledged mode (UM), acknowledged mode (AM), and transparent mode (TM). VoIP is expected to operate in the RLC UM mode.
In a transmitter, a RLC UM entity generates a RLC Protocol Data Unit (PDU) by segmenting, concatenating, or padding a RLC Service Data Unit (SDU) received from a higher layer to a size suitable for transmission on a radio channel and then inserts information about the segmentation/concatenation/padding and a Serial Number (SN) into the resulting data. The RLC PDU is delivered to a lower layer. A RLC UM entity in a receiver recovers the RLC SDU by interpreting the SN and the segmentation/concatenation/padding information of the RLC PDU received from its lower layer. For reference, in the TM mode, the RLC entity simply delivers an RLC SDU received from the higher layer to the lower layer and a RLC PDU received from the lower layer to the higher layer.
The MAC layer serves as an interface between the RLC layer and the PHY layer. It inserts a MAC header into the RLC PDU. Data that the MAC layer delivers to the PHY layer is called a Transport Block (TB).
The PHY layer processes the TB and transmits/receives the TB on a radio channel. The PHY layer also inserts a Cyclic Redundancy Check (CRC) to the TB for transmission and performs an error check on received data using a CRC.
As described above, the voice data generated from the CODEC 106 of the UE 110 is converted to a VoIP packet by the IP/UDP/RTP stack 105. The header of the VoIP packet is compressed in the PDCP layer 104 configured for uplink transmission, processed to a size suitable for transmission on a radio channel in the RLC layer 103, and reconstructed to an RLC PDU in the MAC and PHY layers 102 and 101. The RLC PDU is channel-encoded and then transmitted on the radio channel. In the Node B 110, the RLC PDU or a TB resulting from processing the RLC PDU in the PHY layer is channel-decoded in a PHY layer 111 and then transmitted to the RNC 120. The RNC 120 recovers the RLC PDU to the VoIP packet and transmits it to the CN 130. The CN 130 transmits the VoIP packet to the other party via the IP network 140 or a Public-Switched Telephone Network (PSTN) 150. Downlink data transmission is performed in the reverse order.
For VoIP communications, both the caller and the called party must use the same type of CODECs 106 and 144. If the UE 100 operating in UMTS communicates with a standard landline phone, a specific device between the PSTN 150 and the UMTS CN 130 performs CODEC conversion for the CODEC 154.
CODECs approved by the 3GPP include an Adaptive Multi-Rate (AMR) CODEC. The AMR CODEC is characterized by Unequal Error Protection/Unequal Error Detection (UEP/UED).
The structure of a VoIP packet for transmission on a radio channel will be described in detail.
Referring to FIG. 1, a VoIP packet 160 is comprised of a Radio Protocol (RP) header 161, a Robust Header Compression (ROHC) header 162, a UDP checksum 163, a Payload 164, and a CRC 165 inserted in the PHY layer. The RP header 161 is inserted in the PDCP, RLC and MAC layers. Since a PDCP header and a MAC header are not used in many cases in VoIP communications, the RP header 161 can be a 2-3 byte RLC header.
The ROHC header 162 is a header compressed by a header compression protocol called ROHC in the PDCP layer. Compressible parts of an IP/UDP/RTP header are converted to the ROHC header. The ROHC header 162 is variable in size, generally 2 to 3 bytes.
The UDP header comprises the UDP checksum 163. The UDP checksum 163 is not compressed and positioned after the ROHC header 162. Errors are detected from IP/UDP/RTP data by means of the UDP checksum 163 of about 2 bytes.
The Payload 164 is the data generated from the CODEC. In the case of the AMR CODEC, the Payload 164 is 32 bytes or 9 bytes. The CRC 165, inserted in the PHY layer, is a CRC operation value for the entire packet. The size of the CRC 165 is determined on a per call basis. It is usually 12 bits or 16 bits. The PHY layer of the receiver performs an error check using the CRC 165.
As described above, two error detection schemes, that is, the UDP checksum 163 and the CRC 165 are redundantly applied to the conventional VoIP packet 160 in order to detect errors from the VoIP packet 160 transmitted on the radio channel, resulting in an unnecessary overhead.

Method and apparatus for transmitting/receiving voice over internet protocol packets with a user datagram protocol checksum in a mobile communication system


A chaotic transmitter (100) operates according to preselected chaotic protocols, such as a set of Lorenz equations. Modulation is accomplished by modifying a predetermined parameter of the set of chaotic Lorenz equations with a message signal, thereby producing a spread spectrum chaotic transmitted signal. A corresponding receiver (200) reconstructs a synchronizing drive signal, which is used by a demodulator (412) of the receiver (200) to detect the message signal.

Numerous schemes have been proposed to make radio communications relatively immune to interference and secure from undesired listeners. A simplistic technique for securing such communications is through use of a standard audio encryption system on a conventionally transmitted signal, and use of a corresponding decryption system once the signal is received. A more sophisticated technique, known as spread-spectrum transmission, relies on transmission of an information signal over a wide range of frequencies, using temporal frequency-hopping, broad-band modulation, or other well-known mechanisms.
One encryption scheme, taught in U.S. Pat. No. 5,048,086 to Bianco et al, employs the mathematical theory of chaos by encrypting data with a chaotic equation known as the logistic difference equation.
Other chaotic systems are discussed in L. M. Pecora and T. L. Carroll, Synchronization in Chaotic Systems, 64:8 PHYSICAL REVIEW LETTERS, p. 821 (Feb. 19, 1990) and in T. L. Carroll and L. M. Pecora, Synchronizing Chaotic Circuits, 38:4 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS, p. 453 (Apr. 1991). These articles disclose a theory of synchronizing two chaotic systems, describe a circuit demonstrating such synchronization, and suggest as an application the linking of two remote systems, each with internal signals behaving chaotically, yet in synchronization with each other.
None of the known teachings, however, provides a practical application for synchronized chaotic systems. Ideally, chaotic techniques could be applied to communications systems to provide relatively simple means for achieving robust and secure communications.

Communication using synchronized chaotic systems


A method of manufacturing a hollow spindle, especially for the pivotal mounting of valve-actuating levers to control exhaust-and-intake valves of an internal combustion engine. The spindle has an outer tube, in the interior of which a shaped tubular body is fixed in order to form at least two liquid-carrying chambers. To form a chamber, the tubular body is provided with a cutout extending in the longitudinal direction. The tubular body is a shaped inner tube that, seen in cross-section, has an inwardly-curved region that makes a rounded and stepless transition to the circular region, and of the tubular body. At least the circular region is joined by virtue of its material to the outer tube.

1. Field of the Invention
The invention relates to a method of manufacturing a hollow spindle that serves, in particular, as the mounting for valve-actuating levers that control exhaust-and-intake valves in an internal combustion engine.
2. Description of the Prior Art
A hollow spindle, specifically a rocker lever spindle of the aforementioned type, is known from DE 42 21 708 A1. This rocker lever spindle consists of an outer tube, in the interior of which a shaped tubular body is fixed. By means of the tubular body, which has a longitudinal rib, at least two and preferably three liquid-carrying chambers are formed. In a special embodiment (FIG. 2), the tubular body has a roughly V-shaped cutout that extends in the longitudinal direction to form a chamber. The tubular body is pushed or pressed into the outer tube and fixed in place by cam-type elevations or shapings on the mantle of the tubular body. A disadvantage of this design is that there is no assurance that the fixed position of the tubular body will be maintained or that the chambers will remain sealed under operating conditions. Furthermore, the lengths that can be manufactured are limited, so that production costs are high.
U.S. Pat. Nos. 3,863,328 and 4,125,924, disclose a method for fitting two tubes together in a rattle-proof fashion. After one tube is slipped into the other with a certain diameter clearance, a drawing point is formed on one end of the tubes. The tubes are then cold-drawn one atop the other.

Method of manufacturing a hollow spindle


A manifold assembly useful in patient ventilation/aspiration systems includes a stop cock valve with a hollow stem and a transverse slot arranged to permit the stem to be rotated between open and closed positions. In both positions, a ventilating pathway is maintained through the slot and the stem between ventilator and patient connection ports of the manifold. In open position the stem provides a travel pathway for a catheter between the patient connection port and an access port of the manifold. In closed condition, the stem seals this travel pathway.

1. Field
This invention relates generally to valved manifold devices, and is specifically directed to such devices in medical conduit systems. It provides a valved manifold particularly useful at the patient intubation interface of endotracheal ventilation/aspiration systems.
2. State of the Art
Many gas delivery systems, particularly in a hospital or laboratory environment, utilize manifold devices for directing fluid flow. There are a variety of circumstances in which it is necessary or desirable to provide multiple, yet isolated, other pathways through the interior of such a manifold. The manifold is often associated with other components as a system. When the individual components of such a system are subjected to mechanical forces tending to rotate one component with respect to another, it is often essential to provide that travel path through a joint structure which permits rotating or swiveling movement.
As an example, closed systems for endotracheal suctioning and ventilating typically include a manifold enabling introduction of ventilating gases and intermittent exhalation of patient breath simultaneously with insertion and operation of a tracheal suctioning catheter. The manifold structure typically includes multiple ports, usually the open ends of respective conduits extending from a common chamber. One such port is interfaced to a patient through a patient connection device. The suction catheter is often included within an assembly which is connectable to a second port of the manifold. The catheter assembly conventionally includes a collapsible plastic envelope positioned to entirely surround the catheter. A practitioner manually externally collapses the envelope onto the external surface of the catheter and advances the catheter through the manifold into an access tube connected to a patient, retracting the catheter in a similar fashion following the aspiration procedure.
The manifold thus provides a first pathway for ventilation gases and a second pathway for the catheter. The catheter provides isolation from the ventilating gases for fluids withdrawn from the patient through the manifold. When the catheter is withdrawn, it is often desired to continue regulated ventilation through the manifold. In some cases, it is desirable for the catheter assembly to be disconnected from the manifold without disturbing the ventilation of the patient. It is thus necessary to provide for a gas-tight sealing of the pathway formerly occupied by the catheter upon its removal. Previous efforts in this connection have involved the provision of auxiliary sealing structures for use in association with the manifold. These arrangements have had several disadvantages. Because they have not been integral with the manifold, their use has been inconvenient in practice. Certain resilient seals have been unacceptable because they lack the positive sealing characteristics of a mechanical valve. Available valves are not suitable for incorporation into a manifold because they lack the essential capability of providing a travel path for a catheter when catheter suction is needed. Any sealing arrangement employed should be as inexpensive as possible, thereby eliminating complex mechanical valve assemblies from practical consideration.
Manipulations, or other disturbances, of the catheter assembly tend to cause irritation to the patient and to impose strain on connection points within the assembly. These problems are alleviated to a considerable extent by the provision of a swivel capability (rotation about the longitudinal axis of the connection port) at the patient interface. Unfortunately, the provision of such a capability has heretofore involved the incorporation of swivel elements which are inordinately expensive and/or which provide an unreliable seal for the system.
Material prior art structures and methods are described, among other places, in U.S. Pat. Nos. 5,333,607 to Kee, et. al.; 5,354,267 to Niermann, et. al.; 5,357,946 and 5,445,141 to Kee, et. al. and 5,487,381 to Jinotti. These patents each disclose ventilator manifold devices and systems in which those devices are utilized.
The '267 patent, for example, discloses a manifold and a multi-position stop cock valve. The valve is provided with a "Tee" shaped internal stem channel pattern so that the stem may be positioned selectively to wash the internal lumen of a catheter, to irrigate the patient or to accommodate travel of the catheter through the stem to suction the patient. The valve may be plugged directly into an access port of the manifold. Patient ventilation is conducted without respect to the valve through other ports of the manifold. The valve itself constitutes an integral component of a catheter assembly and must be removed from the manifold with the remainder of that assembly.
There remains a need for an inexpensive, yet reliable, manifold assembly incorporating a valve positioned to minimize dead air space within the manifold and capable of passing a catheter. The valve must provide a sealed gas flow path through the manifold in both its open and closed conditions with respect to catheter travel. The manifold should further be removable from any associated catheter assembly. Ideally, the manifold should also include connection structure capable of providing a sealed passageway through a rotating or swiveling joint.