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This application is a continuation of application Ser. No. 156,624, filed June 5, 1980, and now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates generally to pattern dyeing of textile material, for example carpet, and, more particularly, to the dispensing of multiple dye colors on carpet in a variety of patterns, including irregular and apparently random patterns.
The printing of tufted carpets in well known in the art, and is carried out by a variety of techiques. At the present time, most carpet printing is done by techniques more or less analogous to conventional printing techniques, such as rotary printing and screen printing. The use of such traditional carpet printing techniques requires an individual roller or screen for each color of each individual pattern which it may be desired to print. These rollers or screens are typically twelve or fifteen feet wide, and involve great expense both in initial manufacture and in storage.
Recently, a variety of other techniques have been proposed and implemented to produce a wide variety of visually pleasing carpet printing effects, essentially limited only by imagination.
One attractive alternative to carpet printing techniques is controlled dye jet printing wherein plural colored dyes are sprayed or jetted onto the surface of relatively moving textile material. Generally, such jet printing machines comprise a plurality of dye applicators extending across the path of carpet travel, each dye applicator including a multiplicity of dye outlet tubes or nozzles extending in a line along the applicator transverse to the direction of carpet travel, with the nozzles of each of the applicators being supplied with a different color dye. Each individual nozzle or jet is controllaby actuated by suitable electronic, pneumatic or mechanical means to dispense dyes onto the moving textile material under control of a suitable pattern controller. By way of representative example, one general form of jet printing apparatus, along with various forms of controllers, is disclosed in the following patents: Weber et al U.S. Pat. Nos. 3,443,878 and 3,570,275; Stewart, Jr. U.S. Pat. No. 3,969,779; Kline U.S. Pat. No. 3,985,006; Johnson U.S. Pat. No. 4,033,154; and Varner U.S. Pat. No. 4,116,626. Another, particularly effective type of jet pattern dyeing apparatus is disclosed in pending U.S. Application Ser. No. 085,943, filed Oct. 18, 1979, by Billy Joe Otting, and entitled "Jet Pattern Dyeing of Material, Particularly Carpet," which was continued as application Ser. No. 237,577, filed Feb. 24, 1981, now U.S. Pat. No. 4,341,098.
It will be appreciated that such jet pattern dyeing or printing machines, through suitable programming of the individual closely-spaced dye nozzles, are capable of producing an extremely wide variety of carpet printing effects, particularly when it is considered that dyes of various viscosities may even be employed to produce effects other than would apparently be possible merely with pattern control. With jet printing apparatus, pattern effects may range from extremely intricate and closely repeated patterns, limited only by the resolution of the apparatus determined by nozzle spacing (typically 0.1 inch), to apparently random effects effected by causing irregular shapes of various colors and sizes to be jet printed on the carpet through suitable pattern control.
However, the high precision and resolution possible with a controlled dye jet printer, together with attendant cost, is not necessary for all applications. In the carpet industry, much time and effort is expended to create different and original color patterns in pile materials. Different forms of applicators, although not capable of the resolution of true controlled jet pattern apparatus wherein controlled dye nozzles apply color dyes directly to the carpet, have been proposed employed for pattern dyeing of carpet in varying degrees of randomness, frequently with novel and visually pleasing results.
One such example is known in the art as "TAK" dyeing. In TAK dyeing, carpet is conveyed under a dye applicator which drips or splatters dye onto carpet yarn conveyed below the applicator. The applicator includes a lick roll which picks up dye from a trough, and the dye is scraped from the lick roller by a doctor blade. The doctor blade includes a plurality of individual channels for dividing the dye into a plurality of separate dye streams. The dye streams, as they issue from the doctor blade, are broken up into smaller streams or drippings by mechanical dye stream interrupter elements positioned below the lower edge of the doctor blades. To randomize the pattern, various devices oscillate both the doctor blade carrying the separate streams, and the mechanical interrupter devices. By way of example, such TAK dyeing machines are disclosed in the following patents: Takriti et al U.S. Pat. No. 3,683,649; Appenzeller et al U.S. Pat. No. 3,731,503; and Takriti et al U.S. Pat. No. 3,800,568.
A variation on the TAK dyeing process is disclosed in the Miller et al U.S. Pat. No. 4,127,014. The disclosed Miller et al machine is capable of multicolor TAK dyeing, and includes a pair of opposed identical applicators, each including a plurality of channel-like doctor blade extensions for producing separate dye streams, which are then broken up by various mechanical interrupters positioned below the channel outlets. In addition to the dye scraped by the doctor blade from the dye pick-up roll, adjustable blocking plugs or wedges are provided to stop the flow of dye from particular channels, and a separate dye conduit and valving arrangement permits dye of a color different from the base color scraped off by the doctor blade to fall in place of the dye from individual blocked off channels.
Another variation on the TAK dyeing process is the apparatus disclosed in the Balmforth U.S. Pat. No. 3,937,044. The Balmforth apparatus employs a flat doctor blade, with a separate reciprocating corrugated sheet defining channels disposed beneath the lower edge of the doctor blade.
Another form of more or less random patterning carpet dyeing apparatus is known as a "Polychromatic dyeing machine". Examples are disclosed in the Harris et al U.S. Pat. No. 3,688,530 and the Stankard et al U.S. Pat. No. 3,801,275. A polychromatic dyeing machine comprises one or more rows of dye nozzles or jets, each row of nozzles being mounted on a respective carriage bar which is reciprocal transversely of the carpet web. Liquid dye streams from the nozzles directly onto the carpet web or other fabric to be dyed. If the design pattern to be applied is merely a stripped design, the carriage bars remain stationary during the passage of the carpet web there beneath. When it is intended to vary the pattern, the carriage bars are reciprocated in various predetermined motions. Of similar effect are the machines disclosed in the Chaussabel U.S. Pat. No. 2,218,811 and the Davis et al U.S. Pat. No. 3,785,179.
Still another form of apparatus for dyeing textiles and carpets in more or less random patterns through control of the dye application is known in the art as "Kusters Color", and is for example disclosed in the Leifeld U.S. Pat. No. 3,964,860 and the Moser U.S. Pat. No. 4,170,958. This type of applicator employs a dye pick-up roll which transfers dye in liquid form to a substantially flat, inclined doctor blade. The film of dye flowing over the doctor blade is irregularized by being diverted by means of narrow mechanical scraper blades or air blasts directed at the doctor blade or pick-up roll. In one particular form of the Kusters Color apparatus, the air blasts are delivered by a rotating and reciprocating hollow tube extending across the doctor blade, with a plurality of air outlet openings distributed over the surface of the hollow tube.
Still another form of carpet patterning apparatus is disclosed in the Ahrweiler et al U.S. Pat. No. 4,033,153 wherein a rotating pick-up roll transfers dye from a reservoir trough to a substantially flat doctor blade, and a plurality of vertically pivoting channels are provided at the bottom end of the doctor blade. The channels are individually pivotable between one position in which dye liquid is permitted to flow onto the carpet, and another position in which the liquid dye is directed to a catch pan from which it can be returned to the dye reservoir trough.
Yet another form of apparatus for producing irregular dyeing effects on carpet is disclosed in the Plotz U.S. Pat. No. 3,903,715. In the Plotz apparatus, dye liquid is applied by means of rotating discs arranged in horizontal position above the carpet. Dye liquid is supplied either continuously or in drops to the surfaces of the rotating discs, and centrifugal force divides the dye into individual drops of different size and spreads the dye over the width of the carpet.
Another form disclosed in the Mathes et al U.S. Pat. No. 4,157,652 employs a plurality of rotating drums positioned above the carpet web. Each of the drums has a plurality of cavities formed in the outer surface thereof, and dye is supplied to these cavities. As the drums rotate, dye falls from the cavities onto the carpet web traveling therebeneath, forming an irregular and random pattern.
From the foregoing, it will be appreciated that a wide variety of techniques and apparatus have been proposed for continuous application of color patterns to carpet, in more or less random manner. The present invention provides such apparatus which is highly versatile, capable of producing an extremely wide range of pattern effects, and yet is relatively low in cost. Further, the applicator apparatus of the present invention may be retrofitted at relatively low cost to an existing uniform applicator comprising merely a rotative pick up roll and a doctor blade, with no means to vary the pattern absent apparatus of the present invention. Thus the benefits of the invention may be readily realized, as a practical matter, at minimal expense and inconvenience.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a versatile carpet dyeing applicator substantially lower in cost than a full scale jet printer, but yet which is capable of producing novel and visually pleasing multicolor pattern effects in the carpet ranging from apparently completely random to fairly well defined patterns, limited only by the imagination of the carpet pattern designer.
It is another object of the invention to place in the hands of carpet pattern designers a versatile and effective carpet dyeing apparatus which may be effectively utilized to rapidly test and then commercially produce new and unique carpet designs, which hopefully will gain acceptance in the market place.
Briefly stated and in accordance with an overall concept of the invention, an inclined distributing plate such as a conventional doctor blade extends across the width of the carpet web, transverse to the direction of web travel, with a lower edge of the distributing plate positioned so that dye flowing off the lower falls on the carpet web. In addition, means, such as a conventional dye pickup roller rotating in a dye supply trough, introduces liquid of a base color onto the distributing plate at an upper edge thereof to form a base color dye film initially flowing substantially uniformely downwardly over the distributing plate.
In accordance with the invention, at least one plurality of delivery tubes has outlet ends spaced along the distributing plate with the outlet ends positioned above and directed towards the distributing plate for adding dye or chemical of at least one additional color or other characteristic to the base color dye film in selected areas of the distributing plate. Thus, mixing and spreading occurs on the surface of the distributing plate.
It is contemplated that, in usual applications, the additional dye or chemical will simply be dye of a different color. However, there is no intention to so limit the invention, as it is further contemplated that dyes of different viscosities, for example, can be employed for varied penetration effects. Similarly, various gums or resist chemicals, or even water, might be jetted onto the distributing plate.
Preferably, the dye delivery tube outlet ends are spaced on approximately two inch centers, and are carried by a nozzle bar extending across the width of the carpet web. A mechanism is provided for reciprocating the nozzle bar and dye delivery tubes back and forth in a direction transverse to the direction of web travel. Further, a controlled valving arrangement is provided for selectively providing the dye or chemical of the at least one additional color or characteristic to individual ones of the dye delivery tubes under pattern control.
While as few as one nozzle bar carrying a single set of dye delivery tubes may extend across the width of the carpet bed for supplying additional dye colors to the doctor blade, it is preferred that a plurality, for example three, of independently reciprocating nozzle bars, with separate colors or other characteristics, be provided.
This particular arrangement provides a highly versatile applicator, capable of a wide variety of pattern effects with varying degrees of randomness. Any number of forms of pattern control may be applied to the controlled valving arrangement, such as from a computer or an optical mylar film reader. Further, the nozzle bars may independently reciprocate at different speeds, further randomizing the pattern for various visually pleasing effects. Although, for reasons of cost, resolution is limited by the two-inch center-to-center spacing of the individual dye delivery or nozzle tubes, recognizable and repeatable patterns are produced on the carpet by appropriate pattern control through automatic selective actuation of the valves, if desired. Apparently random actuation patterns may be employed as well.
The two-inch nozzle tube spacing might well be unsatisfactory for many purposes in the event the dye or chemical were sprayed or jetted directly onto the carpet. In such event, stripes of undyed or base color dye might well appear between nozzle tubes. However, with the present invention, the spreading effect of the inclined distributing plate on the dye or other chemical eliminates such gaps. It will therefore be appreciated that the controlled jetting of dye or chemical onto the distributing plate, rather than directly on the carpet, is an important aspect of the invention.
In accordance with another aspect of the invention, a pattern dyeing apparatus is provided for retrofit combination with an existing carpet dyeing machine of the type including a rotating roller supplied with base color dye liquid from a trough, and an inclined doctor blade for scraping dye from the roller to cause a film of base color dye to flow uniformly downwardly over the doctor blade to fall from the lower edge of the doctor blade onto a carpet web conveyed therebelow. In particular, the retrofit pattern dyeing apparatus includes at least one nozzle bar extending across the width of the carpet web and carrying a plurality of dye delivery tubes having spaced outlet ends positioned above and directed towards the doctor blade for adding dye of at least one additional color to the base color dye film in selected areas of the doctor blade, with a mechanism for reciprocating the nozzle bar and dye delivery tubes back and forth in a direction transverse to the direction of web travel.
Preferably, there is a controlled valving arrangement for selectively providing dye to individual ones of the dye delivery tubes under pattern control. It is further preferred that a plurality, for example three, of reciprocating nozzle bars extending across the width of the web be provided, with each of the plurality of reciprocating nozzle bars carrying a row of dye delivery tubes having outlet ends spaced along and positioned above the doctor blade, with the outlet ends directed towards the doctor blade for adding additional dye to the base color dye film.
This retrofit combination approach provides a particularly inexpensive means for a carpet manufacturer to add pattern dyeing applicator apparatus in accordance with the present invention to an existing carpet dyeing line.
For reciprocating or otherwise moving the nozzle tube bars, it will be appreciated that a wide variety of mechanical and electromechanical mechanisms may be provided, and there is accordingly no intention to limit the invention to any particular form of such mechanism. However, a presently preferred form of reciprocating mechanism includes a reverseable pnuematic actuator for each nozzle bar, and a limit switch arrangement for sensing and defining the limit of nozzle bar travel in either direction, and reversing said pnuematic actuator when a limit of travel is reached. The velocity of reciprocation may readily be controlled by controlling the air pressure applied to the pnuematic actuator. Thus, the nozzle bars reciprocate more or less independently at the same time dye is delivered under pattern control.
The present invention additionally contemplates a method for dyeing textile materials such as carpets so as to form patterns thereon, the method including the steps of forming a base color dye film of a width substantially equal to the width of the textile material on an inclined plate, controllably discharging liquid dye streams of at least one additional color on to the upper surface of the inclined plate in selected areas of the inclined plate, laterally varying in reciprocating fashion the position of the liquid dye streams directed onto the inclined plate, and depositing the base color dye and the additional color dye onto the textile material by allowing dye liquid to fall from the lower edge of the inclined plate onto the textile material.
It will be appreciated that the apparatus and methods of the invention provide highly versatile apparatus for producing a wide variety of dye patterns on carpet. In particular, carpet designers are provided with the means to implement any number of nozzle and visually pleasing dyeing effects, heretofore unknown.
BRIEF DESCRIPTION OF THE DRAWINGS
While the novel features of the invention are set forth with particularity in the appended claims, the invention, both as to organization and content, will be better understood and appreciated, along with other objects and features thereof, from the following detailed description taken in conjunction with the drawings, and which:
FIG. 1 is an overall highly-schematic prespective view of a single twelve or fifteen-foot wide applicator in accordance with the invention positioned over a moving carpet web;
FIG. 2 is a section along line 2--2 of FIG. 1 showing the form of mounting arrangement for the reciprocating nozzle bars;
FIG. 3 is a highly schematic overall representation of one suitable form of arrangement for controlling the applicator apparatus of the invention;
FIG. 4 is a highly schematic depiction of one form of controller suitable for use in actuating the controllable valves in the carpet dyeing apparatus of the invention;
FIG. 5 is a cross sectional view of a preferred form of pinch tube valve assembly;
FIG. 6 illustrates the valve of FIG. 5 in the actuated position wherein the flexible tube portion is pinched closed; and
FIG. 7 is an exploded isometric view of a portion of the electrically actuated air valve of the valve arrangement of FIGS. 5 and 6.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring first to FIG. 1, an applicator, generally designated 10, includes a conventional dye reservior trough 12 containing base color liquid dye, and a horizontally disposed rotating dye pick up roll 14 dipped into the trough 12 so as to pick up a dye film. An inclined distributing plate in the form of a conventional doctor blade 16 extends across the width of an underlying conveyed carpet web 18 transverse to the direction of web travel as denoted by an arrow 20. Through scraping action of the doctor blade upper edge 22 which is held by spring pressure against the rotating roll 14, a film of base color liquid dye is introduced onto the doctor blade 16, and flows initially uniformly downwardly thereover to fall from the lower edge 24 thereof onto the carpet web 18.
While a rotating dye pickup roll 12 is illustrated, it will be appreciated that other means may be provided for introducing liquid dye of a base color onto the distributing plate 16, such as a liquid spraying arrangement near the upper edge of the plate 16.
It will be appreciated that FIG. 1 is highly schematic in order to illustrate the essential concepts of the invention, and that a number of structural elements such as side supports are, for clarity of illustration, omitted from the drawing. For example, a support bearing and rotating drive mechanism are required for the pick up roll 14; these are of conventional construction and are not shown. Similarly, a horizontal pivot support and spring are required to urge the doctor blade upper edge 22 against the pick up roll 14; these likewise are of conventional construction and are not shown. It will further be appreciated that the proportions of the applicator are greatly distorted by the break in the center representing omitted structure identical to that which is shown. A typical width for the applicator 10 is twelve or fifteen feet, to suit the width of the carpet web 18, and the applicator 10 may be two or three feet in height.
Although not illustrated in FIG. 1, it will be appreciated that a conventional steam chamber is provided to fix the dyes, as well as other conventional devices such as washers for excess dye and dryers.
In accordance with the invention, a plurality of nozzle bars, for example exemplary nozzle bars 26, 28 and 30 each carry a plurality of dye delivery tube outlet ends comprising individual small-diameter stainless steel tubing sections and collectively designated 32, 34 and 36, respectively, with the individual nozzle tube outlet ends spaced on approximately two inch centers along the respective nozzle bars. Preferably, the nozzle bars 26, 28 and 30 are each drilled to receive individual stainless steel nozzle tubes.
Individual mechanisms, generally designated 38, 40 and 42 are provided for independently reciprocating the nozzle bars and dye delivery tubes back and forth. Preferably, the reciprocating mechanisms 38, 40 and 42 each comprise respective pnuematic actuators 44, 46 and 48 supplied from a compressed air source (FIG. 3). The bodies of the pneumatic actuators 44, 46 and 48 are fixedly mounted through suitable means, and have actuator rods 50, 52 and 54 which move in and out to impart motion to the nozzle bars 26, 28 and 30. The pnuematic actuators 44, 46 and 48 are reversible, and a limit switch arrangement comprising suitably-mounted limit switch pairs 56, 58 and 60 senses the limit of nozzle bar travel in either direction, and reverses the pnuematic actuators 44, 46 and 48 through conventional electromechanical connections (FIG. 3) when either limit of travel is reached.
Thus the nozzle bars 26, 28 and 30 reciprocate essentially independently, and the velocity of reciprocation can be independently controlled by varying the air pressure supplied to the pnuematic actuators 44, 46 and 48.
The mounting and support arrangement which permits reciprocating motion of the nozzle bars 26, 28 and 30 may more clearly be seen by additionally referring to FIG. 2 which shows the mounting and support arrangement for an exemplary nozzle bar 30. In particular, a fixed support plate 62 of general "C" configuration is securely mounted at its ends to side members (not shown), and carries a plurality of upper and lower guide rollers 64 and 66 having horizontal axes of rotation. A movable guide bar 68 has upper and lower guide channels or tracks 69 and 70 which respectively receive the guide rollers 64 and 66 for rolling support therebetween. As may be seen from FIG. 1, it is the guide bars such as the guide bar 68 to which the pnuematic actuator rods 50, 52 and 54 are actually attached. The remaining illustrated element of the nozzle bar mounting and support arrangement is a plate 71 for mounting the nozzle bar 30 to the guide bar 68.
For supplying the dye delivery tube outlet ends 32, 34 and 36, sets of dye delivery tubes 72, 74 and 76 comprising flexible and compressible plastic tubing are supplied from respective dye manifolds 78, 80 and 82 carrying dyes of different colors. For pattern control, a controlled valving arrangement includes valve blocks 84, 86 and 88 comprising individual valves for each of the nozzle tubes 32, 34 and 36 in the entire applicator 10. While a preferred form of valving arrangement is illustrated and described hereinbelow, other forms of valves may also be suitable. There is accordingly no intention to limit the scope of the invention to the precise form of dye valve shown.
In FIG. 1, the dye delivery tube portions 72, 74 and 76 are flexible to permit pinching for selective control of dye flow. A preferred form of valve assembly for multiple inclusion in each of the valve blocks 84, 86 and 88 is a pinch tube valve assembly described and claimed in pending U.S. Pat. Application Ser. No. 086,392, filed Oct. 18, 1979 by Billy Joe Otting, and entitled "PINCH TUBE VALVE." A preferred form of valve is described hereinbelow with particular reference to FIGS. 5, 6 and 7.
A suitable controller 90 (FIGS. 3 and 4) is provided to individually control valves in the valve blocks 84, 86 and 88. A wide variety of controllers are suitable, and there is therefore no intention to limit the present invention to any particular one form of controller. One of the features of the present invention is its versatility in being adaptable to a great many controllers and control concepts.
In the operation of the apparatus 10, the pickup roll 14 rotates, transferring base color dye from the reservior 12 onto the upper edge 22 of the doctor blade 16, whereupon the dye initially flows uniformly in a base color dye film down the doctor blade 22, to fall from the lower edge 24 thereof onto the carpet web 18. Added to the base color dye flowing down the doctor blade 16 are controlled discharges of additional dye colors from the various nozzle tube outlets 32, 34 and 36, which add different colors to the base color dye. Dye is thus mixed and spread on the doctor blade 16 for a wide variety of effects.
By way of specific example, the base color dye in the reservoir 12 may be light tan, and the dye colors selectively dispensed from the respective rows of nozzles 32, 34 and 36 may be dark blue, light green and yellow. Unique and pleasing mixing effects result.
It is optional with the carpet manufacturer user of the apparatus 10 whether to reciprocate any or all of the nozzle bars 26, 28 and 30. If the nozzle bars 26, 28 and 30 are reciprocated, additional pattern effects are produced. As previously mentioned, the reciprocation can be at different velocities through control of air pressure applied to individual pneumatic actuators 44, 46 and 48.
As may be seen from FIG. 1, an additional reciprocating nozzle bar 92 carrying a set of dye outlet tube ends 94 comprising stainless steel nozzle tubes and reciprocated by a pnuematic actuator 96 under the control of a pair of limit switches 97 may be provided, the nozzle tubes 94 applying still another dye color onto the roll 14, rather than on the doctor blade 16. These nozzle tube outlets 94 are similarly supplied from a dye manifold 98 through a valve block assembly 100 under pattern control.
It will be appreciated that an important portion of the applicator 10 comprises the more or less conventional pickup roll 14 and doctor blade 16 assembly which, in the absence of the present invention, would apply dye in a substantial uniform manner to the carpet web 18. Thus, pattern dyeing apparatus of the present invention may be adapted for convenient retrofit to an existing such uniform dyeing apparatus, through the provision of the suitably-mounted reciprocating nozzle bars 26, 28 and 30, the nozzle tubes 32, 34 and 36, and related control and actuating elements.
Referring now to FIG. 3, there is shown an overall representation in highly schematic form of one approach or arrangement for controlling the applicator 10 of FIG. 1. In particular, FIG. 3 illustrates how a representative one 48 of the reversible pneumatic actuators may be controlled, and how an exemplary individual dye control valve in representative valve block 88 may be controlled.
The FIG. 3 system is a pneumatic one, with electrical control valves. Accordingly, a compressor 101 is provided and supplies compressed air through an adjustable throttle valve 102 and through an electrically-operated two-way air valve 103 to appropriate input ports of representative reversible pneumatic actuator 48. The two exemplary limit switches 60 are arranged, through their respective electrical connections 104, to switch the air valve 103 from one position to the other as each limit of travel of the representative FIG. 1 nozzle bar 30 is reached. In operation, the actuator rod 54 moves in and out of the actuator body 48 as the air supply is switched between the input ports of the actuator 48 under control of the air valve 103, which is in turn controlled by the limit switches 60. The actuator 54 then imparts reciprocating motion to the nozzle bar 30. Through adjustment of the throttle valve 102, the reciprocation velocity may be controlled.
A similar arrangement is provided for each of the other FIG. 1 pneumatic actuators 44, 46 and 96, and their motions and velocities can be independently controlled.
In FIG. 3 the compressor 101 additionally supplies compressed air to an air manifold 105, which in turn supplies air for operating each of the many individual dye control valves, such as a representative individual dye control valve 106 in the valve block 88. While a suitable structure for the valve 106 is described hereinbelow with particular reference to FIGS. 5, 6 and 7, in general the valve 106 operates by selectively pinching closed the flexible tube portion 76 under control of an electrically-operated pilot valve 107, in turn controlled by the pattern controller. Preferably, dye flow through every single nozzle in the applicator 10 is controlled by an individual output of the pattern controller 90.
While various forms of controllers may be employed, ranging from sophisticated computer controlled controllers to simply optical mechanical controllers, FIG. 4 illustrates a presently preferred form of pattern controller 90 in highly schematic form. Although the controller 90 operates on a photoelectric principle, it will be appreciated that suitable controllers will take various forms such as electrically or optically sensed rotating drums or endless webs, coded punch cards, coded magnetic tapes, coded magnetic discs, and various forms of computer based controllers employing either or both of mass storage (e.g., magnetic tape or disc) and high speed random access memories. Those skilled in the art of carpet manufacture will recognize that the controller 90 of FIG. 4 is similar in concept to controllers conventionally employed for pattern carpet tufting machines. It will further be appreciated that, whatever controller is selected must provide properly coordinated outputs for individual ones of the valve blocks 84, 86, 88 and 100, and the individual valves in each valve block.
More specifically, the FIG. 4 controller 90 comprises an endless, generally light transmissive web 108, such as Mylar or acetate film, carried by suitable rotating rollers 110 and 112. Representative pattern information is recorded on the film 108 in the form of an opaque area 114 which will ultimately result in a repeating series of controlled valve actuations resulting in a pattern on the carpet depending also upon the positioning of the respective reciprocating nozzle bar 26, 28 and 30 at the time of valve actuation. Within the upper roller 110 is a tubular light source 116. To photoelectrically sense the pattern information, and array 118 of photoelectric elements 120 is provided, together with a fiber optic array 122 to transmit the light signals. The photoelectric elements 120 each comprise a suitable sensor (not shown), such as a phototransistor, and suitable electronic interfacing circuitry. The photoelectric elements 120 serve to output signals on corresponding output lines 124 when light supplied thereto is blocked by the opaque pattern area 114. It will be appreciated that the lines 124 are connected either directly or indirectly to individual dye control valves in the valve blocks 84, 86, 88 and 100.
The fiber optic array 124 thus permits relatively close spacing (e.g., 0.01 inch) of individual pattern elements carried on the Mylar or acetate film 108, while allowing wider spacing as a practical matter between the much larger photoelectric elements 120. A relatively miniaturized controller 90 can thus be provided.
Referring now to FIGS. 5, 6 and 7, there is shown a preferred valve constuction 130, FIG. 5 depicting the valve 130 open condition, and FIG. 6 depicting the valve 130 closed position. The valve 130 is a representative one, and is one of the many included in representative valve block 88 (FIG. 1) to selectively pinch closed representative dye delivery tube flexible portion 76. In the FIG. 5 valve open condition, dye freely flows from the FIG. 1 manifold 82 through the flexible tube 76 to the nozzle tube 36. In the FIG. 6 valve closed position, the flexible tube 76 is pinched off. This preferred form of valve is more particularly described and claimed in the copending application Ser. No. 086,392 filed Oct. 18, 1979 by Billy Joe Otting.
The valve 130 of FIGS. 5-7, generally comprises a pneumatic actuator 132 and an electromagnetically actuated valve portion 134. A tube receiving portion 136 of the valve 130 includes a bore 138 and a communicating passageway 140 at right angles thereto. The tube receiving portion 136 is mounted by means of threads to a support member 141. A flattened portion 141 is formed in the wall of the bore 138 opposite the passageway 140. The passageway 140 receives a ball 144 which actually bears against the tube flexible portion 76. A piston rod 146 actuated by a pneumatic piston 148 in turn bears against the ball 144.
The piston 148 reciprocates within a cylindrical chamber 150 formed in an intermediate portion 152 screw threaded as at 154 to mate with the tube receiving portion 136. An annular seal 156 received in an annular groove 158 of the piston 148 bears against the walls of the cylindrical chamber 150, and a compression spring 160 is provided to urge the piston 148 and piston rod 146 towards the valve-open position illustrated in FIG. 5.
The right-hand end of the intermediate portion 152 includes a passageway 162 for introducing air into and exhausting air from the cylindrical chamber 152 for actuation of the piston 148. A plugged bore 164 communicates with the passageway 162 for selectively controlled venting for valve modulation effects if desired.
The electromagnetic valve portion 134 of the valve 130 may be identical to that disclosed in the Clippard, Jr. et al U.S. Pat. No. 3,921,670, to which reference may be had for further details. The valve portion 134 functions when actuated (FIG. 6) to permit compressed air supplied through a tube 166 and fitting 168 from the compressed air manifold 105 (FIG. 3) into a passageway 170 terminating at a small diameter bore 172 in the end of a truncated insert member 174 communicating with a chamber 175. Air in the chamber 175 is then introduced through the passageway 162 to act against the piston 168 forcing the flexible tube portion 76 closed. In the valve deactuated position as illustrated in FIG. 5, the small diameter bore 172 is closed off by an elastomeric button 176 carried in the central portion 177 of a spider-like spring member 178, best seen in FIG. 7. Spacer rings 179 serve to axially position the spider member 178. In the FIG. 5 valve-deactuated position, the cylindrical chamber 150 is vented through the passageway 162 and the chamber 175 and through a passageway 184 to the atmosphere. This permits the piston 168 to retract to the position of FIG. 5.
The spider member central portion 177 serves as an armature selectively operated by a twenty-four volt DC electromagnetic coil 186 including suitable ferromagnetic structure 188. When the coil 186 is energized, the spider armature 177 is pulled radially away from the small passageway 172 permitting compressed air introduced via the tube 166 to ultimately act on the piston 148. This also causes the elastomeric button 176 to seal off the vent passageway 184. When the electromagnetic coil 186 is not energized, resilience of the spider member 178 urges the elastomeric button 176 against the small diameter passageway 172 closing off the flow of incoming compressed air, and at the same time opening the chamber 175 to the vent passageway 184.
From the foregoing, it will be appreciated that the present invention provides a versatile, yet low cost carpet dyeing applicator which places in the hands of the carpet dyeing industry the means to produce a wide variety of novel and visually-pleasing carpet dyeing effects.
While specific embodiments of the invention have been illustrated and described herein, it is realized that modifications and changes will occur to those skilled in the art. It is therefore to be undertood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit and scope of the invention.
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A versatile carpet dyeing applicator capable of producing novel and visually pleasing multicolor pattern effects ranging from apparently completely random to fairly well-defined. An inclined distributing plate such as a conventional doctor blade extends across the width of the carpet web, transverse to the direction of web travel, with a lower edge of the distributing plate positioned so that dye flowing off falls on the carpet web. Means, such as a conventional dye pickup roller rotating in a dye supply trough, introduces liquid of a base color onto the distributing plate at an upper edge thereof to form a base color dye film initially flowing substantially uniformly downwardly over the distributing plate. At least one plurality of delivery tubes has outlet ends spaced along the distributing plate with the outlet ends positioned above and directed towards the distributing plate for adding dye or chemical of at least one additional color or other characteristic to the base color dye film in selected areas of the distributing plate. Thus, mixing and spreading occurs on the surface of the distributing plate. The dye delivery tube outlet ends are spaced on approximately two-inch centers, and are carried by a moving nozzle bar extending across the width of the carpet web. A controlled valving arrangement selectively provides the dye or chemical of the at least one additional color or characteristic to individual ones of the dye delivery tubes under pattern control. For supplying additional dye colors to the doctor blade, it is preferred that there are a plurality, for example three, of independently reciprocating nozzle bars, with separate colors or other characteristics.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to heating devices. More particularly, the invention comprises a portable heater and cooker system, which relates generally for remote use, and for utility applications, also for comfort heating of tents or small enclosures such as cabs, trailers, fish huts, etc., and also for personal warmth and cooking applications.
2. Description of the Prior Art
Heating devices have had shortcomings in safety, convenience and versatility. Present heating devices consume oxygen from the room when the heating devices are used indoors, possibly causing a lack of oxygen with dangerous consequences. Based on health effects, an average healthy adult should not be exposed to oxygen levels below sixteen percent at sea level.
Numerous heating devices are shown in U.S. Pat. No. 4,860,726, issued to Stanley G. Barker on Aug. 29, 1989, U.S. Pat. No. 4,972,823, issued to Arne H. Stadin on Nov. 27, 1990, U.S. Pat. No. 5,445,137, issued to Paul B. Crews on Aug. 29, 1995, and U.S. Pat. No. 5,467,760, issued to John H. Cox on Nov. 21, 1995, all of which relate to heating devices.
U.S. Pat. No. 4,860,726 to Barker, teaches a multipurpose warming and heating vessel with a versatility in its configurations to be adaptable to supply heat for different warming for the body, limited food warming and cooking applications, as well as the ability to dispense warming heat to service any useful purpose, by means of its flexible discharge tube. The present invention is different from this vessel in that it is a safe heater for small enclosures and permits the targeting of certain objects or areas requiring heat, without exposing them to flame impingement or torch heat.
U.S. Pat. No. 4,972,823 to Stadin, teaches a safety stove and burner assembly which is safe for use in both cooking and heating in close quarters and explosive atmospheres. The present invention is different from this assembly since it is compact, portable, and lightweight.
U.S. Pat. No. 5,445,137 to Crews, teaches a backpacking stove for tent use that will protect the fabric of the tent from a heat source and safely and conveniently exhaust the excess heat, moisture and gases from the tent. The present invention is different from this stove, in that it has a safety feature which prevents the depletion of oxygen which could result in the production of deadly carbon monoxide.
U.S. Pat. No. 5,467,760 to Cox, teaches a portable sportsman furnace which permits ease of portability in utilization of the furnace structure of the invention in various sporting events, such as hunting, fishing and the like. The present invention is different from this furnace, since when heating smaller enclosures there will be warmer floor areas as the air is drawn up from the cold floor area by convection, thus drawing warmer air down from higher spaces.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
SUMMARY OF THE INVENTION
The present invention is a portable heater and cooker system comprising a housing having a heating chamber with a bottom air inlet port and a top air outlet port. A heating component is provided having a structure for mounting the heating component within the heating chamber of the housing. An assembly is provided for supplying a fuel air mixture to the heating component within the housing, so that heating component will produce heat in the heating chamber to create and promote convection establishing a chimney effect through the housing. An angle outlet duct is removably connected to a top air outlet port of the housing to convey hot air from the housing. A facility is provided for safely shutting down the heating component when there is a lack of oxygen for the heating component.
Accordingly, it is a principal object of the invention a portable heater and cooker system that will overcome the shortcomings of the prior art devices.
An additional object of the invention is to provide a portable heater and cooker system that is a safe heater for small enclosures, also to permit the targeting of certain objects or areas requiring heat, without exposing them to flame impingement or torch heat.
A further object of the invention is to provide a portable heater and cooker system that is compact, portable and lightweight.
Still yet a further object of the invention is to provide a portable heater and cooker system that does not require a high voltage power supply.
Another object of the invention is to provide a portable heater and cooker system that has a safety feature to prevent the depletion of oxygen which could result in the production of deadly carbon monoxide.
Still yet another object of the invention is to provide a portable heater and cooker system in which the safety feature, being an oxygen depletion sensor, can be retrofit to existing heaters.
Still yet a further object of the invention is to provide a portable heater and cooker system that is simple and easy to use.
Yet another object of the invention is to provide a portable heater and cooker system that is versatile.
Still yet another object of the invention is to provide a portable heater and cooker system that with a simple revision can be used for cooking.
A further object of the invention is to provide a portable heater and cooker system, so that when heating smaller enclosures, will circulate air about the enclosure by convection, drawing colder air in and up from the floor to be heated.
Still yet another object of the invention is to provide a portable heater and cooker system that is economical in cost to manufacture.
It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
FIG. 1 is a side view of the present invention.
FIG. 2 is a front view taken in the direction of arrow 2 in FIG. 1.
FIG. 3 is a perspective view taken in the direction of arrow 3 in FIG. 2.
FIG. 4 is a perspective view similar to FIG. 3, with the angled outlet duct removed and the outlet grid in position for cooking.
FIG. 5A is a perspective view similar to FIG. 3, showing a ventilating panel for small enclosure heating.
FIG. 5B is a perspective view similar to FIG. 5A, showing a modified ventilating panel and a vent tube in place for small enclosure heating.
FIG. 6 is a cutaway front view with the angled outlet duct exploded therefrom.
FIG. 7 is a front view with the angled outlet duct removed, showing a primary air tube to cool the oxygen depletion sensor.
FIG. 8 is a schematic wiring diagram for the safety shut-down facility.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to the drawings, in which similar reference characters denote similar elements throughout the several views, FIGS. 1 through 7 illustrate the present invention, which is a portable heater and cooker system 10 comprising a housing 12 having a heating chamber 14, a bottom air inlet port 16 and a top air outlet port 18. A heating component 20 is provided. A mounting structure 22 is for mounting heating component 20 within heating chamber 14 of housing 12.
Some heaters typically of the camping type have a wire frame (not shown) in place of a fully enclosed housing and heating chamber. The actual structure of the housing and heating chamber is not critical to the invention. Therefore, it will be understood that for the purposes of this invention, "housing" and "heating chamber" encompass the generally open structure of a wire frame as well as the continuous walls depicted herein. In a similar vein, air inlets and outlets need not be separate unto themselves, but will encompass any opening in the heating chamber passing air thereinto and out therefrom. A fuel assembly 24, exterior to housing 12, is provided for supplying a fuel air mixture to heating component 20, so that when heating component 20 produces heat in heating chamber 14, a chimney effect circulates air through housing 12. An angle outlet duct 26 is removably connected to top air outlet port 18 of housing 12, to redirect and convey hot air 27 from housing 12. A safety shut-down facility 28, shown in FIGS. 6 and 8, is provided for safely shutting down heating component 20 when there is a deficiency of oxygen for heating component 20.
A lift handle 30 is located on housing 12. A side hand grip 32, shown in FIG. 2, is on housing 12, so that housing 12 can be manually manipulated to heat various items. Heating component 20 is a radiant burner 34. An outlet grid 36 is provided. When angled outlet duct 26 is removed from top outlet port 18 of housing 12 and replaced by outlet grid 36, system 10 will be converted to a flat cooker, so that a standard cooking vessel 39 can be supported on outlet grid 36, as shown in FIG. 4.
Angled outlet duct 26 is adjustable upon top outlet port 18 of housing 12, to allow selective redirection of hot air 27. Outlet grid 36 is removably attached to an opening located at top 38 of angled outlet duct 26. An inlet grid 40 cooperates with bottom air inlet port 16 of housing 12, whereby protection from foreign elements is provided to the heating chamber 14 with heating component 20, without diminishing desired air movement through housing 12 created by the chimney effect.
Safety shut-down facility 28, shown schematically in FIG. 8, wherein a suitable control circuit is illustrated, includes an on-off switch 42 and an audible alarm 44 activated by an oxygen depletion sensor 46, the latter being a light intensity responsive photocell. A dimming of a usual bright glow of heating component 20 indicates a lack of oxygen in the combustion air and is used as a safety cutoff point for heating component 20. Alternatively, any qualitative or substantial quantitative change in the radiant energy emitted during combustion may be monitored by a suitable sensor as the basis for determining when oxygen is nearing depletion. For example, hue of the flame may vary as percentage of oxygen in combustion air diminishes. In this example, the sensor may respond to hue rather than to brightness. Any measurable parameter of combustion indicative of oxygen depletion would be suitable for the purposes of this invention.
Oxygen depletion sensor 46 sends a signal to a thermocouple cut off circuit 47, which is connected to a fuel shut off solenoid valve 49 to cut off fuel. A jumper may be installed to close the circuit of solenoid valve 49 when it is deemed not necessary to monitor for oxygen depletion. Oxygen depletion sensor 46 includes a primary air tube 48, shown in FIG. 7, extending to fuel air mixture supply assembly 24, to prevent sensor 46 from overheating. The temperature of sensor 46 is kept below a critical point by a flow of cool air 50. If desired, sensor 46 may be protected from exposure to excessive heat by shielding (not shown) or by being located away from injurious heat.
Oxygen depletion sensor 46 optionally includes a clip 52, so that sensor 46 can be removably attached adjacent to heating component 20 in retrofit applications. Clip 52 is flexible, for enabling sensor 46 to be adapted to different locations on different housings 12.
FIG. 5A shows a ventilating panel 54 having an air inlet opening 56. Ventilating panel 54 is mounted into a wall of an enclosure, such as a tent 55. Panel 54 is placed against an opening formed in the enclosure. A securing assemblage, a gripping element such as clips 60, is provided for securing housing 12 adjacent to ventilating panel 54 (or panel 54A, shown in FIG. 5B), so that ventilating panel 54 (or 54A) will draw ambient air from outside the enclosure through air inlet opening 56, with panel 54 supported at the opening formed in the enclosure being heated. A screen 58 fits over air inlet opening 56 in ventilating panel 54 or 54A, to prevent insects and small animals from entering through air inlet opening 56. Clips 60 on ventilating panel 54 engage with lift handle 30 when pivoted down. A stabilizer rod 62 extends between ventilating panel 54 and housing 12.
FIG. 5B shows a modified ventilating panel 54A having a second air outlet opening 64. An upwardly inclined vent tube 66, connected at its lower end to top end 38 of outlet duct 26 extends through second air outlet opening 64 in ventilating panel 54A, so as to vent out some hot air 27 produced by heating component 20. This induces air circulation for ventilation.
A cover 68 in FIG. 5A is for capping air inlet opening 56 in ventilating panel 54, so as to maintain the integrity of the enclosure when portable heater and cooker system 10 is detached. In FIG. 5B, a first cover 70 is for capping air inlet opening 56 in ventilating panel 54A. A second cover 72 is for closing air outlet opening 64 in ventilating panel 54A, so as to maintain the integrity of the enclosure when portable heater and cooker system 10 and upwardly inclined vent tube 66 are detached.
It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.
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A portable heater and cooker system is provided to apply radiant and conductive heat from a heating component to an enclosure area or a cooking utensil, using a heat generated chimney effect and manual manipulation. In addition, user safety is assured with an oxygen depletion sensor and a ventilating panel for the enclosure.
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This application is a continuation of application Ser. No. 12/460,704, filed Jul. 22, 2009, now U.S. Pat. No. 7,992,819.
BACKGROUND OF THE INVENTION
This invention concerns sewing supplies and equipment.
Seamstress work, using one or more sewing machines, usually requires a collection of spools of different thread, as well as bobbins for the various spools, often holding thread particular to a spool. The spools and bobbins are often switched frequently on a sewing machine.
Quite a number of devices have been conceived to accommodate multiple spools and/or bobbins for retrieval and storage in sewing. These come in a wide variety of forms. See, for example, U.S. Pat. Nos. 5,913,485, 5,727,699, 4,351,458, 4,195,739, 4,029,241, 3,948,396, 3,738,590, 2,944,761, 1,508,105, 1,405,554, 470,328, 462,702 and Des. 146,869. See also U.S. Pat. Nos. 6,789,771, 4,094,415, 3,491,893 and 2,431,423 showing devices for holding other articles not related to sewing, but with certain mechanical features having some pertinence to the invention.
There is a need for a convenient, compact and versatile spool holder, preferably also for bobbins, to keep these items together and readily available for retrieval and storage.
SUMMARY OF THE INVENTION
The spool holder of the invention is simple in concept but highly versatile, compact and efficient in use. The holder comprises a base plate or rack that is narrow and elongated and formed of molded plastic material, preferably a material that is relatively rigid but with some degree of give. To this base plate are attached, via an elongated slot through the length of the base plate, a series of preferably rubbery spindles, each with a stem long enough to hold a thread spool and optionally a bobbin stacked at the end of the thread spool. The spindles have heads with a peripheral groove, formed by a pair of axially spaced apart rubbery discs, and the base plate has a hole, basically keyhole-shaped to receive the heads of inserted spindles. The spindles can then be entered into the slot, to be slid along the slot or track to desired positions.
The spindles preferably can be inserted from either face of the base plate, so that their stems extend at right angles from the base plate in either direction, allowing dense storage of thread spools. Each spindle stem is at least slightly laterally compressible (in some portion of its length) so as to exert a force within the core of each thread spool (and bobbin) when the thread spool is forced down over the spindle, slightly compressing and deforming some portion of the spindle. For this purpose the spindle stems in one embodiment have a U-shaped cross section, and can have a thickened region near the head. Spools and bobbins are held in place by frictional engagement with the spindle.
It is thus among the objects of the invention to enable versatile, dense storage of thread spools of different sizes, with a device that allows the user to adjust positions of spool-engaging spindles as desired, for efficient storage and retrieval of spindles, and preferably also bobbins. These and other objects, advantages and features of the invention will be apparent from the following description of a preferred embodiment, considered along with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing a thread spool holder according to the invention, with spindles and spools attached.
FIG. 2 is a perspective view illustrating the manner in which a spool holder spindle is assembled into a base plate of the device.
FIG. 3 is a cross section view through the base plate, showing retention of a spindle.
FIG. 4 is detail view in perspective showing one of the spool holder spindles.
FIG. 5 is a cross section view showing the configuration of the stem of the spindle, taken in the plane 5 - 5 in FIG. 4 .
DESCRIPTION OF PREFERRED EMBODIMENTS
In the drawings, FIG. 1 shows a spool and bobbin holder device 10 of the invention, including a base plate or rack 12 formed of molded plastic material. This rack is elongated, and may be about eight to nine inches in length, more broadly between about six inches and fifteen inches in length. Other lengths can be selected for particular applications. As the drawing shows, the base plate has an elongated slot 14 within which are engaged a series of spool holder spindles 16 , which can be formed of a rubbery plastic material such as urethane. In one form the spindles are made from a thermoplastic elastomer, about 85 durometer on the A scale. The rack or bar 12 may be, for example, ABS 109 on the R scale. The spindles hold thread spools 17 . An individual spindle 16 is shown in FIG. 4 . The spindle 16 has a grooved head 18 , with a groove 20 which preferably is annular, defined between two integral discs 22 and 24 on either side of the groove 20 . An integral stem or shaft, not seen in the drawings, extends axially between these discs. As shown in FIGS. 4 and 5 , the spindle stem 26 in this preferred embodiment is generally U-shaped. This enables inward compressibility of the stem (to smaller effective diameter) for a spool 17 pushed onto the spindle, or for a bobbin. The spindle 16 is integrally molded and is somewhat flexible. It has a spindle stem 26 that extends essentially linearly from the head 18 .
As shown in FIG. 1 , a significant number of thread spools 17 , 17 a , 17 b , 17 c , etc. can be attached onto the device. In fact, the thread spools can be quite densely packed, into contact with one another as shown at 17 a and 17 b , and the spindles 16 can be arranged as closely as permitted by the width of the spools. This position adjustment feature of the device, along with the ability to arrange the spindles 16 to extend in both opposed directions, each essentially at right angles to the plane of the base plate or bar, allows very dense storage of thread spools on the device when desired.
FIG. 2 demonstrates that the spindles 16 are assembled into the slot 14 of the base plate or rack 12 by inserting the spindle head 18 into a generally keyhole-shaped opening 28 in the base plate, alongside and contiguous with the slot 14 . The keyhole opening may be essentially a circular opening 28 with a narrow adjoining channel 30 leading into the slot 14 . The channel or gap 30 is just wide enough to allow the shaft 31 (see FIG. 4 ) at the axial center of the head 18 to slide through when pushed in that direction by a user. Although the spindle heads 18 and the opening 28 are shown as circular, they could be other shapes, such as elliptical, square or rectangular. Circular is preferred, but the important feature is that the head be passed into an access opening which may be a similar shape to the head but in any event allows the head to pass through. Also important is that the gap 30 be narrow so as to engage the head while allowing its central shaft to slide through with one of the head discs 22 , 24 adjacent to and engaged with each opposed face (front and back as seen in FIG. 2 ) of the base plate. The circular shape provides for adequate gripping of the grooved head onto the plate edges 32 , while allowing for relatively easy sliding of the spindle via its head 18 along the length of the slot for repositioning the spindle as desired. Non-circular head shapes will operate but may experience binding more than the circular shape, which produces less contact with the plate edges 32 and allows for some rolling when sliding, avoiding binding.
Although the opening 28 for the spindle heads is shown set off to one side of the slot 14 , it could be otherwise positioned. For example, the hole could be centrally positioned on the slot, straddling both plate edges 32 , although this would require more care when an engaged spindle is slid past the opening, so as not to unintentionally dislodge the spindle. Also, such location of the hole would have the disadvantage of preventing the positioning of a spindle at that location when needed for storing thread spools densely on the device. The hole could be positioned at either extreme end of the slot, although again, this would eliminate those positions for retaining a spindle.
FIG. 3 shows the device of the invention in cross section, and illustrates a spindle 16 assembled into the slot 14 of the base plate or rack 12 . This cross section shows in more detail how the spindle is retained in place. The head 18 of the spindle straddles the slot 14 , with the plate edges 32 of the slot engaged in the annular groove of the spindle head 18 . The two discs 22 and 24 that form the head are shown on opposed sides of the base plate 12 and of the slot plate edges 32 . The spindle stem 26 extends out at right angles from the plane of the rack or plate 12 . FIG. 3 also illustrates margins or border ridges 35 preferably bordering the slot region and spaced apart so as to define a track that closely fits to the head of the spindle. The track provides greater stability.
FIGS. 3 and 4 also show a feature of a preferred embodiment for retaining the thread end from a thread spool or a bobbin retained on a spindle. Although no thread spool or bobbin is shown in FIG. 3 or 4 , these views show a side notch 38 in the side of one leg of the U-shaped spindle stem 26 , and also a similar notch 40 preferably included in the bottom of the U at the outer end of the spindle 26 . The notch 38 may be, for example, roughly ⅛ inch back from the end of the spindle 26 . The depth of each notch is minimal and can be, for example, 1 mm or less, and the width of each notch can be approximately similar. At the bottom of the end notch 40 is a slit in the plastic material of the U-shaped spindle stem 16 , this slit being shown at 42 . FIG. 4 , though not showing a spool or bobbin, schematically indicates the manner in which the notches and slit are used. A thread end 44 is shown, the end of a spool or a bobbin of thread and extending off the spool or bobbin in the same direction as the thread is wound on the spool or bobbin. The thread is placed into the notch 38 and then, within the U shape of the spindle stem 26 , is brought up to the end notch 40 and pulled downwardly to engage the thread in the slit 42 to firmly retain the thread end in place. The slit 42 can be, for example, about ⅛ inch deep. Since the bobbin (or spool) is held firmly on the spindle, the thread end will be retained securely against unwinding.
FIG. 5 shows a spindle 16 in cross section, as seen generally in the plane 5 - 5 in FIG. 4 . Another feature of the invention, as seen in FIG. 5 and also in FIG. 3 , is that the stem 26 of the spindle 16 in a preferred embodiment tapers to a larger dimension, i.e. a larger effective diameter, in a base portion 26 a adjacent to the head 18 . This provides for a tighter, more positive gripping of the thread spool by its center core as the spool reaches the end of the spindle stem and is positioned close to or in contact with the base plate. In fact, the spindle stem 26 can be of a dimension to allow thread spools to freely slide over the outer regions of the stem, while becoming firmly engaged only at the base of the stem. The outer end of the spindle, although a thread spool might fit loosely over it, can firmly engage a bobbin 36 as shown in FIG. 1 . The length of the spindles in a preferred embodiment preferably is sufficient for storing a bobbin outboard of a spool. Bobbins generally have a slightly smaller core diameter than thread spools. The length of the spindle stem is at least about two inches, and preferably, in the case of accommodating bobbins, at least about two and one-half inches and ideally about two and five-eighths inches to two and three-quarters inches. More broadly the length of the spindle stem should be in the range of about two inches to three inches, and preferably about two and one-half inches to three inches for accommodating bobbins.
The spindles can be used independently of the base plate or rack, to keep spools and bobbins together.
The invention encompasses variations to the preferred embodiment described. Although the spindles may be formed of a somewhat rubbery elastomer material, a harder plastic could be used. A surface friction characteristic is preferred. The base plate or rack 12 could be other than straight as shown; its elongated slot could be curved, compound-curved, or even in a circle or ellipse, interrupted with crossbars to hold the base plate together.
The above described preferred embodiments are intended to illustrate the principles of the invention, but not to limit its scope. Other embodiments and variations to these preferred embodiments will be apparent to those skilled in the art and may be made without departing from the spirit and scope of the invention as defined in the following claims.
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A thread spool holding device has a plastic base plate that holds a series of preferably soft plastic spindles that can be introduced or removed from the base and can be arranged as needed by sliding along a slotted track of the base. Each spindle can hold a threaded spool and has a cross sectional configuration for gripping the center hole of the spool. The spindle ends can also hold a bobbin in tandem with a thread spool.
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BACKGROUND OF THE INVENTION
The present invention relates to an image recording apparatus comprising a recording head in which a plurality of light-emitting sections are aligned along a single dotted line or plural dotted lines and the image recording apparatus conducts image recording on a photosensitive material with exposure light emitted by the light-emitting section while shifting the photosensitive material relatively to the recording head.
When image recording is conducted on a photosensitive material by an image recording apparatus comprising a recording head in which a plurality of light-emitting sections are aligned along a single dotted line or plural dotted lines, in such a manner that the photosensitive material is exposed with exposure light emitted by the light-emitting section while being shifted relatively to the recording head, the developed photosensitive material may get a desired even image density, however, there may be problems from time to time that the image density of the developed photosensitive material may become higher or lower.
The above phenomenon was notable when the processing amount was too small. Accordingly, the problems were supposed to be caused by malfunction of the developing process or by malfunction of the exposure control system, and the true causes were not known. However, as a result of trial and error, the inventor learned that the cause of the problems may be that the light emission amount of the light emitting section of the recording head in the above image recording apparatus fluctuates depending on its working history.
SUMMARY OF THE INVENTION
The objective of the present invention is to solve the above problems and to avoid density fluctuation in a developed photosensitive material due to light emission amount fluctuation of the light emitting section of the recording head depending on its working history in the above image recording apparatus.
The cause of the light emission amount fluctuation of the light emitting section of the recording head was not sufficiently investigated. However, the following phenomenon may be considered. That is, in the case that a vacuum fluorescent print head (VFPH) is used as the recording head, electrons are adapted to fly in a chamber on a vacuum condition. However, gas remains in the chamber and the gas adhere on a fluorescent member of the light emitting section. Initially, when electrons hit to the fluorescent member, light emission amount gradually increases to a stable light emission amount. Further, in the case that an LED array is used as the recording head, its working temperature increases due to self-heat generation to a stable temperature, and a light emission amount may decreases as the temperature increases.
The inventor learned that by conducting preliminary light emission the influence of the above working history may be reduced. As a result, the inventor conceived the present invention. That is, the above problems may solved by the structure described in each of the following items.
Item 1. In an image recording apparatus comprising a recording head in which a plurality of light-emitting sections are aligned along a single dotted line or plural dotted lines and the image recording apparatus conducts image recording on a photosensitive material with exposure light emitted by the light-emitting section while shifting the photosensitive material relatively to the recording head, the image recording apparatus is characterized in that before the image recording on the photosensitive material is started after the power source for the apparatus is turn ed on, preliminary light emission to let the light-emitting sections of the recording head emit light is conducted.
With the structure described in Item 1, the density fluctuation of the developed photosensitive material due to the light emission amount fluctuation of the light emitting sections of the recording head depending on its working history can be avoided.
Incidentally, the term “before the image recording on the photosensitive material is started after the power source for the apparatus is turned on” means the time period before the image recording to form an image for actual use on the photosensitive material is conducted after the power source for the apparatus is turned on. A setup image recording or an image recording for a reference image is excepted from the consideration on this period. Needless to say, after the preliminary light emission, it may be preferable to prepare such a setup image recording and an image recording for a reference image.
Usually, an automatic processing machine is used in such a way that the power source is turned on in the morning, kept on during the day time, and turned off in the evening. In this case, the preliminary light emission can be conducted with a simple control right after the power source is turned on. Since the preliminary light emission does not interfere with actual image recording, it may be preferable. In the case of timer operation, it goes without saying that power source ON by the timer means “the power supply ON”.
Item 2. The image recording apparatus described in Item 1, wherein the light emitting period of the preliminary light emission by the light emitting section is 30 minutes or less.
With the structure described in Item 2, the density fluctuation of the developed photosensitive material due to the light emission amount fluctuation of the light emitting sections of the recording head depending on its working history can be avoided. In addition, if emission time is 10 minutes or less, fluctuation of density can be prevented. In addition, it is preferable that using time of the machine can be shortened.
Item 3. In an image recording apparatus comprising a recording head in which a plurality of light-emitting sections are aligned along a single dotted line or plural dotted lines and the image recording apparatus conducts image recording on a photosensitive material with exposure light emitted by the light-emitting section while shifting the photosensitive material relatively to the recording head, the image recording apparatus is characterized in that preliminary light emission to let the light-emitting sections of the recording head emit light is conducted for every predetermined time.
With the structure described in Item 3, the density fluctuation of the developed photosensitive material due to the light emission amount fluctuation of the light emitting sections of the recording head depending on its working history can be avoided.
Incidentally, the predetermined time is preferable to be 24 hours or less. In this case, the light emission period of the preliminary light emission may be 30 minutes or less. However, it may be not limited to such a period. For example, it may be permissible to conduct the preliminary light emission for 30 minutes for every 24 hours or for 10 minutes for every 8 hours. In addition, if aforesaid predetermined times are slightly increased or decreased, the effects of the present invention can still be obtained. Therefore, to conduct the procedure every 24 hours may be repeated within several hours every morning.
Item 4. The image recording apparatus described in Item 3, wherein the predetermined time is not longer than 30 minutes.
With the structure described in Item 4, the density fluctuation of the developed photosensitive material due to the light emission amount fluctuation of the light emitting sections of the recording head depending on its working history can be avoided. In addition, if the predetermined time is 10 minutes or less, fluctuation of density can be prevented and it is preferable that using time of the machine can be reduced.
Item 5. In an image recording apparatus comprising a recording head in which a plurality of light-emitting sections are aligned along a single dotted line or plural dotted lines and the image recording apparatus conducts image recording on a photosensitive material with exposure light emitted by the light-emitting section while shifting the photosensitive material relatively to the recording head, the image recording apparatus is characterized in that the recording head is controlled to conduct preliminary light emission to let the light emitting sections emit light for every predetermined timing.
Item 6. The image recording apparatus described in Item 5, wherein the preliminary light emission is conducted for each processing order.
With the structure described in Items 5 and 6, by conducting the preliminary light emission for each printing order, the light emission amount can be made stable without delaying the image outputting time. Herein, the term “every timing” means every output for a single print, every processing order or every predetermined number of prints. Further, “each processing order” means a single piece of roll film with 24 frames or 36 frames in the case of a negative film or a single sheet of print when one customer requests a single sheet of photograph for identification.
Item 7. The image recording apparatus described in Item 6, wherein the preliminary light emission is conducted right before starting recording an image on a photosensitive material.
With the structure described in Item 7, the density fluctuation of the developed photosensitive material due to the light emission amount fluctuation of the light emitting sections of the recording head depending on its working history can be avoided.
Incidentally, the term “right before starting recording an image on the photosensitive material” means 5 minutes before starting recording an image. It may be preferable that the preliminary light emission is conducted 1 minute or more preferably 30 seconds before starting recording an image.
Item 8. The image recording apparatus described in Item 7, wherein the preliminary light emission for each printing order is not longer than 60 seconds.
Item 9. The image recording apparatus described in either one of Items 1 to 8, wherein the intensity of light emitted for the preliminary light emission is greater than that emitted for recording an image on the photosensitive material.
With the structure described in Item 9, the density fluctuation of the developed photosensitive material due to the light emission amount fluctuation of the light emitting sections of the recording head depending on its working history can be avoided. By conducting the preliminary light emission with the intensity of light greater than that emitted for recording an image on the photosensitive material, the preliminary light emission can be conducted stably in a short time. As a method of raising the intensity of light, to raise a set voltage, or to drive all elements simultaneously may be used so as to obtain the intensity of light greater than that emitted for recording an image on the photosensitive material.
Item 10. The image recording apparatus described in either one of Items 1 to 9, wherein the light emitting time period of the light emitting sections for the preliminary light emission is longer than the average of the light emitting time period of the light emitting sections for the image recording.
With the structure described in Item 10, the density fluctuation of the developed photosensitive material due to the light emission amount fluctuation of the light emitting sections of the recording head depending on its working history can be avoided.
Item 11. The image recording apparatus described in either one of Items 1 to 10, wherein correction data for the intensity of emitted light among the light emitting sections are obtained during the preliminary light emission or after the preliminary light emission.
With the structure described in Item 11, the density fluctuation of the developed photosensitive material due to the light emission amount fluctuation of the light emitting sections of the recording head depending on its working history can be avoided, and also the correction data for the intensity of emitted light among the light emitting sections can be obtained, thereby time loss for conducting both operations separately can be saved.
As a method of obtaining the correction data, a method of measuring densities on an image recorded on the photosensitive material by a measuring device such as a scanner or a densitometer or a method of measuring directly the luminance of light by a sensor may be used. Especially, the method of measuring directly the luminance of light by a sensor may be preferable, because the correction data can be obtained quickly and simply. In the case of the method of measuring directly the luminance of light by a sensor, it may be preferable to prepare the reference data in advance and to obtain the correction data from the deviations for the reference data.
As the correction data, the data to correct the difference in light emission amount among the light emitting sections of the recording head or the LUT data to correct the light emitting characteristics of the recording head may be listed.
Item 12. The image recording apparatus described in either one of Items 1 to 11, wherein the recording head is subject to aging process.
With the structure described in Item 12, the density fluctuation of the developed photosensitive material due to the light emission amount fluctuation of the light emitting sections of the recording head depending on its working history can be avoided.
The term “the recording head is subject to aging process” means that the recording head is treated so as to stabilize its characteristics, for example, in the case of an electrically-driven recording head, the recording head is held for 100 hours under the normal temperature and the normal pressure on the condition that the recording head is applied with the electricity, or is applied with the electricity under a high temperature.
Item 13. The image recording apparatus described in either one of Items 1 to 12, wherein the recording head is a vacuum fluorescent print head.
With the structure described in Item 13, the density fluctuation of the developed photosensitive material due to the light emission amount fluctuation of the light emitting sections of the vacuum fluorescent print head depending on its working history can be avoided.
Item 14. The image recording apparatus described in Item 13, wherein when the vacuum fluorescent print head dose not conduct the image recording, at least one of cathode voltage, grid voltage and anode voltage is turned off.
Item 15. The image recording apparatus described in Item 13, wherein when the vacuum fluorescent print head dose not conduct the image recording, all of cathode voltage, grid voltage and anode voltage are turned off.
With the structure describe in Items 14 and 15, by turning off a voltage to activate or scatter the remaining gas in the vicinity of the phosphor such as cathode voltage, grid voltage or anode voltage when the vacuum fluorescent print head dose not conduct the image recording, the remaining gas can be prevented from adhering the phosphor so that the light emission amount can be made stable.
Item 16. The image recording apparatus described in either one of Items 1 to 12, wherein the recording head is a LED array.
With the structure described in Item 16, the density fluctuation of the developed photosensitive material due to the light emission amount fluctuation of the light emitting sections of the LED array depending on its working history can be avoided.
[Explanation of technical terms]
As a plurality of light emitting portions arranged in one row of or a plurality of rows of dotted lines, the following configurations are preferable: as shown by FIG. 1 ( a ), a plurality of light emitting portions are arranged in one line-like of dotted row; as shown by in FIG. 1 ( b ), a plurality of light emitting portions are arranged in two line-like dotted rows; as shown by in FIG. 1 ( c ), a plurality of light emitting portions are arranged in three line-like dotted rows, or similar arrangement. In this connection, in FIGS. 1 ( b ) and 1 ( c ), the light emitting portions are arranged in different positions with respect to the arrangement direction, however, a plurality of rows of the light emitting portions may be arranged in the same position.
Further, as the light emitting section of “a recording head in which a plurality of light-emitting sections are aligned along a single dotted line or plural dotted lines”, a LED light emitting element of an LED array, a fluorescent light emitting element of a vacuum fluorescent print head (VFPH), a respective shutter of PLZT shutter array placed in front of a light source, a respective liquid crystal shutter of a liquid crystal array placed in front of a light source, and the other end of optical fiber whose one end is connected to a respective light emitting source, may be used.
As a photosensitive material, a silver halide photographic light sensitive material may be preferable. However, the photosensitive material is not limited to this, a photoreceptor for an electrophotography or a light sensitive resin such as a photopolymer may be used. As the silver halide photographic light sensitive material, a monochromatic photographic light sensitive material or a color photographic light sensitive material may be used. Further, a photographic paper or a photographic film may be used. Still further, a photographic light sensitive material for printing, a photographic light sensitive material for photographing or a photographic light sensitive material for copying may be used.
In the present invention, the preliminary light emission may be conducted by a part of the recording head. For example, by conducting the preliminary light emission separately by the light emitting section having odd numbers and by the light emitting section having even numbers in the recording head, an excessive temperature raise can be avoided and the light emitting characteristics can be effectively stabilized.
As the recording head capable of obtaining the effect of the present invention, an LED array, or a fluorescent print head (VFPH) may be used. Especially, with the fluorescent print head (VFPH), a remarkable effect can be obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 ( a )-( c ) are views showing examples of a plurality of light emitting portions arranged in one row or a plurality of rows of dotted lines.
FIG. 2 is a general perspective view of an image recording apparatus of the present invention.
FIG. 3 is a general perspective view showing an inside of VFPH used in the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An example according to the present invention will be described below, however, the present invention is not limited to the example. Further, in the example, although conclusive expressions are used for the terminology, these show a preferable example of the present invention, and meanings of terminology or technological scope of the present invention are not limited to them.
Embodiment
The image recording apparatus in the present embodiment comprises an exposure head, in which a plurality of light emitting portions are arranged in one row of or a plurality of rows of dotted lines. The image recording apparatus records an image by exposing with light emitted from the recording head a photographic paper which is a silver halide color photographic light sensitive material containing silver chloride of 90 mol% or more in the composition of the silver halide. Referring to FIG. 2, which is a general perspective view of the image recording apparatus of the present example, the image recording apparatus will be described below.
As a photographic paper 2 exposed in the image recording apparatus, a color photographic paper having light sensitive layers sensitive for primary color light of R, G and B such as a color photographic paper having a red sensitive layer for coloring in cyan, a green sensitive layer for coloring in magenta and a blue sensitive layer for coloring in yellow may be used preferably, and a color negative photographic paper or a color positive photographic paper also may be used preferably.
An image processing control circuit 1 converts inputted color image data into output image data for each primary color, and sends it to a signal processing section 10 . The signal processing section 10 has therein a signal processing circuit for each primary color. Each primary color signal processing circuit of the signal processing section 10 is connected to a corresponding exposure head 41 , 51 , and 61 conducting exposure for a corresponding primary color. Each signal processing circuit of the signal processing section 10 corrects the inputted output image data according to correction data, generates a driving control signal from corrected output image data, and sends the signal to the exposure heads 41 , 51 , and 61 . In the exposure heads 41 , 51 and 61 , each light emitting section emits light according to the sent driving control signal.
In the image recording apparatus, a magazine 21 is set in a predetermined direction and position, and accommodates a roll-like photographic paper 2 therein. A feeding roller pair 23 conveys the photographic paper pulled out of the magazine 21 , so as to be pulled out or returned. An exposure unit 40 comprising fixed exposure heads 41 , 51 , and 61 exposes the photographic paper conveyed by the feeding roller pair 23 , thereby conducting image recording. On the basis of the information of a counter to count driving pulses of a driving step motor of the feeding roller pair 23 , the image processing control circuit 1 conducts the image recording for the image data corresponding to a single image line.
A transparent glass plate 33 closely contacting with the photographic paper, is provided between the exposure heads 41 , 51 , 61 and photographic paper 2 . The lower end surface of the transparent glass plate 33 is the exposure image forming surface of each of exposure heads 41 , 51 , and 61 , and the photographic paper 2 is positioned on the exposure image forming surface by the transparent glass plate 33 . The image recording apparatus has a pressing member 31 to position the photosensitive surface of the photographic paper 2 on the lower end surface of the transparent glass plate 33 when the photographic paper 2 is exposed. When the photographic paper 2 is exposed, the pressing member 31 presses the photographic paper 2 onto the transparent glass plate 33 , and in other cases, the pressing member 31 is separated from the transparent glass plate 33 .
In this connection, the exposure head 41 is the exposure head to expose the light of R, the exposure head 51 is the exposure head to expose the light of G, and the exposure head 61 is the exposure head to expose the light of B.
Exposure heads 51 and 61 are respectively fluorescent display tube type vacuum fluorescent print heads (VFPH) which have a phosphor illuminating a blue-green beam. As shown in FIG. 1 ( b ), they have 2560 pieces of 300 dpi fluorescent illuminant elements of zinc oxide phosphor (ZnO:Zn) which is a luminescent section capable of illuminating in a double rows of equally spaced dots. On each fluorescent illuminant element, a Selfoc lens array, which is an aggregate of lenses having a lens function, is located at the prescribed position on the front side thereof. On transparent glass plate 33 surface which faces exposure head 61 , a blue filter (LEE filter 181 marketed by Konica Color Material Co., Ltd.) is provided for exposing B light. On transparent glass plate 33 surface which faces exposure head 51 , a yellow filter (LEE filter HT015 marketed by Konica Color Material Co., Ltd.) is provided for exposing G light.
With regard to the double rows of equally spaced dots, each row may be illuminated alternately.
A mechanism in which a illuminating section on aforesaid vacuum fluorescent print head is actuated will be simply explained based on FIG. 3 which is a schematic perspective view inside the vacuum fluorescent print head. Each illuminating section 74 on aforesaid vacuum fluorescent print head is a phosphor element which illuminates when an electron beam is collided thereon. Below aforesaid illuminating section 74 , anode electrode 75 , which is a transparent electrode, is superposed. Above illuminating section 74 , wire 76 , which is a cathode electrode common to the whole illuminating section is bridged. Around each illuminating section 74 , grid electrode 77 which is common to the whole illuminating section is provided in such a manner not to contact anode electrode 75 . Each anode electrode is respectively connected to circuit 78 for recording head. Aforesaid anode electrode 75 , grid electrode 77 and circuit 78 for recording head are located on transparent plate 79 . Aforesaid anode electrode 75 , all illuminating sections 74 , wire 76 , which is a cathode electrode and grid electrode 77 are tightly enclosed in vacuum space. On wire 76 , which is a cathode electrode, 5.2 V A.C. voltage at which frequency is 100 kHz and Duty ratio is 50% is impressed. On grid electrode 77 , 40V positive voltage is impressed. On anode electrode 75 controlled to illuminate, 24 V positive voltage is impressed. On anode electrode 75 controlled to not illuminate, 5 V positive voltage is impressed.
Then, an electron beam which started from wire 76 tries to reach the grid electrode and the anode electrode controlled to illuminate. An electron beam which started from wire 76 tries to reach the anode electrode controlled to illuminate touches illuminating section 74 which is a phosphor. Then, illuminating section 74 which is a phosphor illuminates. The illuminated material transmits anode electrode 75 , which is a transparent electrode, and transparent plate 79 , and then, image-formed on a light-sensitive material by means of a Selfoc lens array.
Suppose that VA represents a voltage impressed to anode electrode controlled so that illuminating and VG represents a voltage impressed to a grid electrode, VA/VG becomes 0.6. Since aforesaid value is less than 0.9, inter-effect of illuminating sections adjoining each other can be reduced, and since it is larger than 0.3, sufficient illuminating amount can be obtained.
Exposure head 41 has 640 pieces of 300 dpi illuminating section which are LED illuminating elements whose peak wavelength is 665 nm. Aforesaid illuminating sections are located in a form of one row in a form of dot line having equivalent intervals. A Selfoc lens, which is an aggregate of lenses having lens function on each LED illuminating element is located at a prescribed position in front of aforesaid illuminating elements.
Due to setting in advance, image processing and control circuit 1 can illuminate all illuminating sections on the recording head at a certain time set in advance and at an illuminating intensity set in advance (impressed voltage) immediately before recording an image set in advance or every certain time interval. By setting as above, image processing and control circuit 1 functions as a control means which conducts preliminary illuminating which illuminates the illuminating sections on the above-mentioned recording head before starting image recording onto the above-mentioned light-sensitive material after charging the apparatus power supply or a control means which conducts preliminary illuminating which illuminates the illuminating sections on the above-mentioned recording head at every prescribed times.
EXAMPLES
Only exposure head 51 (exposure head for G use) was operated so that a photographic image in which a face of a person was the main object and the background was a gradation from white to black was continuously outputted for 3 days. After continuous outputting, wedge images were outputted. After that, difference of density at a position corresponding to a portion where white background had been recorded by exposure head 51 and density at a position corresponding to a portion where black background had been recorded by exposure head 51 was observed, provided that the cathode voltage, the grid voltage and the anode voltage were turned OFF except when images were outputted.
Experiment Number 1-1
With regard to each of image recording, preliminary illuminating having the same impressed voltage as that for image recording was conducted by the whole illuminating section for 2 seconds since 7 seconds before the starting point of image recording until 5 seconds before it.
Experiment Number 1-2
With regard to each of image recording, preliminary illuminating having the same impressed voltage as that for image recording was conducted by the whole illuminating section for 10 seconds since 15 seconds before the starting point of image recording until 5 seconds before it.
Experiment Number 1-3
With regard to each of image recording, preliminary illuminating having the same impressed voltage as that for image recording was conducted by the whole illuminating section for 20 seconds since 25 seconds before the starting point of image recording until 5 seconds before it.
Experiment Number 1-4
With regard to each of image recording, preliminary illuminating having the same impressed voltage as that for image recording was conducted by the whole illuminating section for 60 seconds since 65 seconds before the starting point of image recording until 5 seconds before it.
Experiment Number 1-5
With regard to each of image recording, preliminary illuminating having the same impressed voltage as that for image recording was conducted by the whole illuminating section for 120 seconds since 125 seconds before the starting point of image recording until 5 seconds before it.
Experiment Number 1-6
With regard to each of image recording, preliminary illuminating, in which impressed voltage was increased by 10 V compared with the image recording was conducted by the whole illuminating section since 10 seconds before the starting point of image recording until 8 seconds before it.
Comparative Experiment Number 2-1
Preliminary illuminating was not conducted.
Experiment Results
Experiment number
Results
1-1
A:
Difference of density could not
discriminated.
1-2
A:
Difference of density could not
discriminated.
1-3
B:
Difference of density could
scarcely discriminated.
1-4:
B:
Difference of density could
scarcely discriminated.
1-5:
C:
The difference of density was
almost invisible. Therefore,
there is no practical problem.
1-6:
A:
Difference of density could not
discriminated.
2-1: (comparison)
D:
Difference of density is so
prominent that the result can not
be put into practical use.
Experiment 2
An experiment was conducted in the same manner as in Experiment 1 except that the vacuum fluorescent print head on exposure head 51 was replaced with aged vacuum fluorescent print head. As a result, in all experiments of 1-1 through 1-6, improvement effects were observed. As is apparent from above, by emitting the head at a certain interval, stable outputting becomes possible. Using time of the machine can be reduced and workability can be increased without damaging the effects of the present invention, preferably when 60 seconds or less, more preferably when 20 seconds or less and more preferably when 10 seconds or less.
On every day, at a prescribed time, power supply for the image recording apparatus was actuated. A photographic image in which a face of a person was the main object and the background was a gradation from white to black was subjected to image recording for 10 sheets every day. The, the power supply was cut off. Aforesaid procedure was continued for 14 days. Prints taken on the first day and those on 14th day were compared. (1) the difference of color balance and density of prints taken on the first day and those on 14th day were compared. (2) the unevenness of color balance and density of prints taken on the first day and those on 14th day were compared, provided that the cathode voltage, the grid voltage and the anode voltage were turned OFF except when images were outputted.
Experiment 3-1
Each of image recording was subjected to preliminary illuminating under the same impressed voltage as the image recording by the whole illuminating section for 30 minutes at a period between the actuating the power supply and the starting point of image recording.
Experiment Number 3-2
An experiment was conducted in the same manner as in Experiment 3-1 except that the vacuum fluorescent print head on exposure heads 51 and 61 were replaced with aged vacuum fluorescent print head and that LED array on exposure head 41 was replaced with aged LED array.
Experiment 3-3
Each of image recording was subjected to preliminary illuminating under the same impressed voltage as the image recording by the whole illuminating section for 30 minutes at a period between the actuating the power supply and the starting point of image recording. Then, in order to obtain the correction data of illuminating strength between each of illuminating section on each exposure head, in each exposure head, pixels were lit in a prescribed order. Then, the resulting correction data were set.
Experiment 3-4
This experiment was conducted in the same manner as in Experiment 3-2 except that the time of the preliminary emission was set to be 10 minutes.
Experiment 3-5
This experiment was conducted in the same manner as in Experiment 3-4 except that the cathode voltage, the grid voltage and the anode voltage were turned ON.
Comparative Experiment Number 4-1
Image recording was conducted in which the preliminary illumination was conducted.
Experiment Results
Experiment number
Evaluation (1)
Evaluation (2)
3-1
F
I
3-2
G
J
3-3
G
J
3-4
G
J
3-5
G
I
4-1 (Comparative)
E
H
Remarks
E: Apparently, there was a difference in terms of color balance or density.
F: Though there was a difference in terms of color balance or density, there is no practical problem.
G: Difference in terms of color balance or density could not be discriminated.
H: Apparently, there was unevenness in terms of density.
I: Though there was unevenness in terms of density, there is no practical problem.
J: Unevenness in terms of density could not be discriminated.
As is apparent from above, by conducting preliminary emission after power supply ON or at every prescribed time, stable image outputting becomes possible.
In addition, it is found that preliminary emission time is ordinarily 30 minutes or less and preferably 10 minutes or less from the viewpoint of stable outputting and mechanical workability.
By the use of a print head subjected to aging, the effects of the present invention is provided more effectively. In addition, by turning the cathode voltage, anode voltage and grid voltage OFF when the images are not outputted, the effects of the present invention is provided more effectively.
According to the present invention, the density fluctuation of the developed photosensitive material due to the light emission amount fluctuation of the light emitting sections of the recording head depending on its working history can be avoided.
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An image recording apparatus is provided with a recording head in which a plurality of light emitting sections are aligned along a single dotted line or plural dotted lines, and a shifting device for shifting photosensitive material relatively to the recording head so that an image is recorded on the photosensitive material with exposure light emitted by the light emitting sections while the photosensitive material is shifted relatively to the recording head. The recording head is controlled to conduct preliminary light emission to let the light emitting sections emit light before the image recording on the photosensitive material is started.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR 1.57.
BACKGROUND OF THE INVENTION
[0002] Steam turbine power generation plants are one of the oldest power generators and supply most of the world's power.
[0003] One conventional steam turbine power generation plant operates according to a process in which high pressure saturated steam from a steam generator is fed, directly or indirectly, to a high pressure wet steam turbine and is expanded and cooled therein with the associated generation of power by the turbine. Cooled and expanded steam from the turbine may be supplied to a moisture separator/reheater and then via a low pressure steam turbine to a condenser. Condensed steam from the turbine may be supplied to a de-aerator and returned, generally through a feed pump and feed heaters, to the steam generator. A plant based on such a conventional wet steam cycle is described in ‘Advances in Power Station Construction’, GD&CD, Central Electricity Generating Board published by Pergammon Press 1986.
[0004] Conventionally, the cooled and expanded steam supplied to the moisture separator/reheater is generally separated into two streams. A first stream comprising separated moisture may be supplied to the de-aerator in combination with condensed steam from the turbine. A second stream is reheated and supplied to a low pressure steam turbine for further power generation. Reheating of this stream in the moisture separator/reheater is effected by steam from the steam generator and/or extracted from the high pressure wet steam turbine.
[0005] Steam from the low pressure steam turbine is exhausted to a condenser, from which water is pumped through one or more low pressure feed heaters before being supplied to the de-aerator and thence back to the steam generator. The low pressure feed heaters may be supplied with heating steam extracted from the low pressure turbine.
[0006] Many attempts have been made to improve the efficiency of conventional steam raising plant, in particular nuclear plant, by combining into the steam cycle the exhaust power output from a gas turbine. Examples of such attempts are disclosed in Japanese Laid-open patent publication nos. 2003027906, 11344596, 10089016, 10037717 and 3151505, and in U.S. Pat. No. 5,457,721.
[0007] One hybrid power generation plant disclosed in UK Patent GB 2431968A operates according to a process in which part of the steam from a conventional steam generator is superheated using the heat in the exhaust gases of a gas turbine. The superheated steam is passed directly or indirectly to be expanded in a steam turbine, thereby generating power.
[0008] In this hybrid power generation plant, part of the feedwater to the steam generator is also supplied to an evaporator also heated by the gas turbine exhaust gases. The steam produced in the evaporator is mixed with the steam from the steam generator. Conventionally the exhaust gases of the gas turbine are directed to first heat the steam from the steam generator and then to evaporate additional feedwater in the second heat exchanger.
[0009] Improvements to this power generation plant have been sought to enable the process to maximize steam flow to the steam turbine when little or no steam is available from the steam generator. Such an improvement would allow the power plant to deliver its full capacity when the steam generator was being maintained or when maximum production of power was needed to respond to the demands on the electricity network.
[0010] There is a current and growing need for efficient power generation in many areas of the world to meet energy demands while reducing carbon emissions. The production of low carbon power by many renewable technologies varies over a wide range of timescales according to weather, season or time of day. Power generation from other sources needs to balance this variation while meeting the daily, weekly and seasonal patterns of demand from consumers. There is thus an increasing need for efficient power generation technologies that can deliver different levels of output flexibly when required to balance power demands while minimizing carbon emissions.
[0011] Further, there remains a need to provide an improved process and apparatus for power generation which improves energy efficiency and therefore lowers cost and damage to the environment in relation to conventional power plants. In particular, the use of a combined cycle power plant in conjunction with a nuclear power plant using either the pressurized or boiling water cycles offers opportunities for efficiency improvement.
[0012] However, it has proved difficult in practice to realize such improvements, for example because of the restrictions imposed by nuclear safety requirements and the limitations of electrical transmission network operation. Nuclear safety requirements generally mean that external disturbances to steam flows in the steam generators should be minimized or avoided. The electrical transmission network limitations mean that single breakdowns should not result in losses of generation above a defined maximum value. These restrictions limit acceptable configurations of the combined gas turbine and nuclear steam cycles. In one of its aspects, the present invention comprises a plant configuration that offers the desired high levels of efficiency within these limitations.
SUMMARY OF THE INVENTION
[0013] According to one embodiment of the present invention, there is provided a process for power generation comprising: providing a steam generator, first, second and third steam turbines, a reheater, a gas turbine, at least one heat exchanger and a combustion means for burning fuel in hot gas, the process having plural modes of operation.
[0014] In various embodiments, the present invention provides process and plant for power generation comprising: providing a steam generator; first, second and third steam turbines; a reheater; a gas turbine; and at least one heat exchanger; supplying a first stream comprising steam from the steam generator to the first steam turbine to generate power in the first steam turbine; recovering from the first steam turbine a recovered stream comprising steam and supplying at least a part of the recovered stream to the reheater; supplying a second stream comprising steam from the steam generator to a first zone of the heat exchanger and heating the second stream therein by supplying at least one hot exhaust gas from the gas turbine to the first zone of the heat exchanger; supplying the heated second stream to the second steam turbine to generate power therein; supplying a third stream comprising steam from the steam generator to the reheater to heat the recovered stream from the first steam turbine; recovering from the reheater a heated recovered stream from the first turbine; and supplying at least part of the heated recovered stream from the first turbine to the third steam turbine to generate power therein, wherein an exhaust gas can be obtained from the heat exchanger and an additional source of fuel combusted with the exhaust gas before it is supplied back to the heat exchanger.
[0015] In an embodiment, the first mode of operation is one comprising: supplying a first stream of feedwater to the steam generator and generating a steam output therefrom; supplying a first stream comprising steam from the steam generator to the first steam turbine to generate power in the first steam turbine; recovering from the first steam turbine a recovered stream comprising steam and supplying at least a part of the recovered stream to the reheater; supplying a second stream comprising steam from the steam generator to the heat exchanger and heating the second stream therein by supplying at least one hot exhaust gas from the gas turbine to the heat exchanger; supplying the heated second stream to the second steam turbine to generate power therein; supplying a third stream comprising steam from the steam generator to the reheater to heat the recovered stream from the first steam turbine; recovering from the reheater a heated recovered stream from the first turbine; and supplying at least part of the heated recovered stream from the first turbine to the third steam turbine to generate power therein.
[0016] In an embodiment, the second mode of operation is one comprising: supplying a first stream of feedwater to the steam generator and generating a stream of steam therefrom; supplying a first stream comprising steam from the steam generator to the first steam turbine to generate power in the first steam turbine; recovering from the first steam turbine a recovered stream comprising steam and supplying at least part of the recovered stream to the reheater; supplying a second stream comprising steam from the steam generator to the reheater to heat the recovered steam from the first steam turbine; recovering from the reheater a heated recovered stream from the first steam turbine; and supplying at least part of the heated recovered stream from the first steam turbine to the third steam turbine to generate power in the third steam turbine.
[0017] In an embodiment, the third mode of operation is one comprising: supplying feedwater bypassing the steam generator to the heat exchanger and heating the feedwater stream therein by supplying at least one hot exhaust gas from the gas turbine to the heat exchanger; and recovering heated steam from the heat exchanger and supplying at least part of the recovered heated steam stream to the second steam turbine to generate power in the second steam turbine;
[0018] In an embodiment, the fourth mode of operation is comprising: at least one of two additional modes of operation corresponding to the first and third modes of operation respectively and comprising the additional steps of recovering an exhaust gas stream from the heat exchanger and combusting an additional fuel to reheat the exhaust gas stream before it is supplied back to the heat exchanger.
[0019] At least one embodiment, the present invention therefore provides a more efficient process for generating power, which makes use of any energy that would otherwise be lost in the exhaust gas from the heat exchanger. The heat exchangers used in one embodiment of the present invention are not 100% efficient and so there will be some heat remaining in the exhaust gas. Conventionally, this would be lost as the exhaust gas would be released after it has passed through the heat exchanger, as the temperature of the gas would be too low for it to be used to generate steam.
[0020] However, in at least one embodiment, the present invention utilizes an additional fuel source to raise the temperature of the waste gas, thereby allowing it to be supplied back to the heat exchanger to generate steam, which can then be used to power the steam turbines. The combustion of the additional fuel allows a much higher proportion of the energy in the exhaust gas to be used than is possible in hybrid systems of the prior art. This therefore means that the generation capacity when the steam generator is not available is much increased compared to hybrid plants of the prior art.
[0021] In one embodiment, a preferred process in accordance with the invention the heat exchanger has plural zones, including at least a first zone and a second zone. The plural zones of the heat exchanger may be separate and may comprise separate heat exchangers.
[0022] In this situation, the separate heat exchanger zones may have different roles within the arrangement of at least one embodiment of the present invention. This allows the heat exchanger zones to operate under different conditions and with different sources of energy. It also means that the heat exchanger zones can communicate with each other in a manner that would not be possible if they were interconnected.
[0023] For example, at least one exhaust gas stream may be recovered from the first zone of the heat exchanger and then supplied to the second zone of the heat exchanger. This means that the exhaust stream from the first zone may be used to at least partially supply the energy required to generate steam in the second zone. This therefore reduces the amount of energy that is wasted within the system and thereby improves efficiency.
[0024] If the energy in the exhaust stream of the first zone is not sufficient to supply the energy required to generate steam in the second zone, the additional fuel may be combusted to reheat the exhaust gas before it is supplied to the second zone of the heat exchanger. This will then increase the temperature of the exhaust stream to a level sufficient to generate steam in the second zone.
[0025] The first mode of operation may comprise supplying the second stream comprising steam from the steam generator to a first zone of a heat exchanger, wherein the second stream is heated therein by supplying at least one hot exhaust gas from the gas turbine to the first zone of the heat exchanger.
[0026] In an embodiment, the first mode of the present invention may further comprise the steps of: supplying a second stream of feedwater to the second zone of the heat exchanger; generating a stream comprising steam; and mixing the steam from the second zone of the heat exchanger with the second stream of steam from the steam generator.
[0027] This therefore allows separate functioning of the first and the second zones of the heat exchanger, so that the two can perform different roles in the arrangement of at least one embodiment of the present invention. Specifically, the first zone of the heat exchanger heats the steam required to power the second steam turbine while the second zone creates steam to supplement that provided by the steam generator.
[0028] The features of the steam required for these different functions may also differ and so the two heat exchanger zones should be able to function under different conditions. Additionally, this allows the exhaust gas from the first zone to be used in the second zone, with or without the additional fuel being combusted, as different levels of energy may be required.
[0029] The stream comprising steam created in the second zone of the heat exchanger in the first mode of operation may further comprise water. This stream may therefore be supplied to a separator before the steam in the stream is mixed with the second stream of steam from the steam generator and the water produced in the separator may be recirculated to the second zone or be supplied to the steam generator as at least part of the feedwater supplied thereto. This further improves the efficiency of the arrangement of at least one embodiment of the present invention.
[0030] In the third mode of operation of the plant, the feedwater bypassing the steam generator may be supplied to the second zone of the heat exchanger in which it is heated and at least partially evaporated before the steam stream therefrom is supplied to the first zone of the heat exchanger. This enables the system to generate power in the second steam turbine independently of the operation of the steam generator.
[0031] The first zone of the heat exchanger in the third mode of operation may be heated using at least one hot exhaust gas from the gas turbine. This is a convenient source of energy for the generation of steam. This hot exhaust gas may then be passed to the second heat exchanger, which may operate at a lower temperature than the first. However, if the temperature is too low to create steam, the additional fuel may be combusted. This therefore improves efficiency while allowing the temperatures in the heat exchanger zones to be controlled.
[0032] The third mode of operation may comprise: supplying the at least partially evaporated heated feedwater stream from the second zone of the heat exchanger to a separator; and recovering from the separator a steam stream and supplying said steam stream to the first zone of the heat exchanger.
[0033] As discussed above, the use of a separator may further improve the efficiency of the process.
[0034] Preferably in said first mode of operation of the plant, the second stream from the steam generator is supplied to the first zone of the heat exchanger at a temperature and pressure not substantially below that of the second stream as it is recovered from the steam generator. For example, the pressure of the second stream as it is supplied to the first zone of the heat exchanger is not more than about 15%, preferably not more than about 10%, most preferably not more than about 5% below the pressure of the second stream as it exits the steam generator.
[0035] The output streams from the second and third steam turbines are preferably supplied, in whole or in part to one or more condensers. In one preferred process according to an embodiment of the invention, at least part of the output stream from the second steam turbine condenser is supplied to a third zone of the heat exchanger and heated therein by supplying at least one hot exhaust gas from the gas turbine to the third zone of the heat exchanger. The heated recovered condensate may then be returned to a de-aerator heated with steam extracted from between stages of the second turbine. The part of the output stream from the condenser supplied to the third zone of the heat exchanger may also be passed through one or more low pressure feed heaters.
[0036] The heat exchanger is preferably arranged so that the at least one hot exhaust gas is passed against at least one first heat transfer surface in the first zone of the heat exchanger to heat second stream from the steam generator, so that the at least one hot exhaust gas is passed against at least one second heat transfer surface in the second zone of the heat exchanger to heat the auxiliary heating stream for the reheater, and so that the at least one hot exhaust gas is passed against at least one third heat transfer surface in the third zone of the heat exchanger to heat the recovered condensate stream from the condenser, or part of it. Preferably, the at least one hot exhaust gas from the gas turbine is passed sequentially against the at least one first heat transfer surface, the at least one second heat transfer surface and the at least one third heat transfer surface, becoming progressively cooler from the first to the third zones of the heat exchanger. The thus cooled at least one hot exhaust gas may then be discharged from the plant by any suitable means, such as by means of a stack.
[0037] In one process according to an embodiment of the invention, the first steam turbine is a wet steam turbine and the steam in the first stream from the steam generator is supplied at or at close to a saturated condition. The first steam turbine preferably operates under a high pressure condition, by which is meant by way of example only that the pressure of steam supplied thereto is at least about 40 bar abs. The third steam turbine preferably operates under a relatively low pressure condition, by which is meant by way of example only that the pressure of steam supplied thereto is less than about 10 bar abs. Preferably the second steam turbine is operable at a pressure intermediate between that of the first and third steam turbines, more preferably at a pressure as close as possible to that of the first steam turbine.
[0038] The flow ratio of the stream supplied to the second steam turbine to the first steam stream from the steam generator may be between about 0.05 to about 0.5, preferably between about 0.05 to about 0.2.
[0039] In one preferred process according to an embodiment of the invention, the total enthalpy of the at least one hot exhaust gas stream supplied from the gas turbine is from about 0.05 to about 0.35, preferably from about 0.05 to about 0.25, most preferably from about 0.07 to about 0.15, of the net enthalpy of materials recovered from the steam generator (that is the enthalpy of the first steam stream supplied from the steam generator minus the enthalpy of feedwater stream).
[0040] The ratio of maximum energy added in additional fuel to energy in exhaust gases of gas turbine may be between 50 to 120%, preferably between 60 and 110% and more preferably between 80 and 100%.
[0041] Preferably the reheater also functions as a moisture separator. Wet steam exhausted from the first steam turbine is passed to the moisture separator/reheater which removes moisture droplets which are returned directly or indirectly as feedwater for the steam generator. The recovered moisture stream may be supplied to the de-aerator separately or together with the part of the recovered stream from the first steam turbine. As with the first steam turbine recovered stream part, the moisture supplied to the de-aerator may be passed to the steam generator via a feed pump and at least one, optionally high pressure, feed heater.
[0042] Preferably the water from the de-aerator is supplied to a feedwater pump which pressurizes it and applies the stream to at least one high pressure feedwater heater. The recovered heated stream from the at least one feedwater heater is supplied to the steam generator. The at least one feedwater heater may be supplied with steam extracted from the first steam turbine to heat the feedwater.
[0043] In another preferred first mode of operation the process comprises: providing feedwater to the second zone of the heat exchanger, the feedwater stream being heated in the second zone of the heat exchanger by the at least one hot exhaust gas; recovering a heated feedwater stream from the second zone of the heat exchanger and supplying the recovered heated feedwater stream to a separator; recovering from the separator the heated feedwater stream and supplying the recovered stream to the steam generator as at least part of the feedwater supplied thereto.
[0044] Conveniently, in said second mode of operation of the plant, the second stream from the steam generator is supplied directly to the heat exchanger, by which is meant in particular that it is not first supplied as input to any steam turbine or heat exchanger.
[0045] Preferably the first steam stream is supplied from the steam generator at a pressure of from about 40 to about 80 bar abs.
[0046] Preferably the temperature and pressure of the second steam stream are substantially the same as the first steam stream.
[0047] Preferably the temperature and pressure of the third steam stream are substantially the same as the first steam stream also.
[0048] Preferably, the first stream comprises the majority of the steam generator output, for example at least about 55% thereof, more preferably at least about 70% thereof.
[0049] In another preferred process the heated recovered condensate from the third zone of the heat exchanger may be supplied to a second deaerator. In this alternative process the separate at least one feed pumps pressurize the water from the second deaerator and deliver low temperature feedwater to the second zone of the gas turbine energy recovery heat exchanger.
[0050] The heat exchanger may be constructed as a single unit with multiple stages therein, or may be constructed as separate units, preferably arranged in series.
[0051] The heat exchange tubes may be of any suitable material, such as the various grades and specifications of steel appropriate to the internal and external conditions and may included extended surfaces such as finning necessary for optimum heat transfer.
[0052] The feedwater used to provide steam to the second steam turbine may be isolated from the feedwater used to provide steam to the first and/or third steam turbines. This may include isolating the stream that originates from the steam generator from that which passes through the heat exchanger. In this embodiment, there are therefore two separated pathways in which water and/or steam can flow. However, the two pathways are thermally connected, with heat passing between the two.
[0053] In one embodiment, the first mode of operation may not require steam to pass directly from the steam generator to the heat exchanger. Instead, the transfer of steam may be indirect. The first mode of operation may further include passing the second stream comprising steam from the steam generator to a steam heated evaporator in which a flow of feedwater that is isolated from the second stream comprising steam from the steam generator is evaporated by at least partially condensing the second stream comprising steam from the steam generator. This isolated stream may be subsequently passed to the heat exchanger and then onto the second steam turbine.
[0054] The first mode of operation may further include passing the condensed water recovered from the second steam turbine through one or more feedheaters in which the condensed water is heated by cooling or at least partially condensing the second stream comprising steam from the steam generator. These feedheaters act to further thermally connect the two pathways and mean that much of the heat from the second stream comprising steam from the steam generator is transferred to the second pathway, which generates power using the second turbine.
[0055] There may be a feedheater directly after the condensed water is recovered. In one embodiment, the condensed water stream is split, with one stream going to the heat exchanger and another going to the feedheater. Preferably, if there are multiple heat exchangers, the condensed water is passed to the second heat exchanger. The two condensed water streams may then subsequently be combined.
[0056] Additionally or alternatively, a feedheater may be present after the condensed water has been passed through the heat exchanger. If there are multiple heat exchangers, the feedwater may pass from the second heat exchanger, to this feedheater, before being passed back to the first heat exchanger.
[0057] According to a second aspect of an embodiment of the present invention, there is provided a power generation plant configured to operate the process described herein.
[0058] In various embodiments, the process of the invention when exemplified in a preferred process in accordance with embodiments of the invention has the following significant advantages:
[0059] It significantly improves the thermal efficiency of the gas turbine and the saturated steam cycles integrated in the hybrid cycle. The net thermal efficiency of the hybrid cycle may for example be about 39%-42% compared with the base saturated steam cycle at 33%.
[0060] When the improvements are attributed to the addition of the gas turbine cycle, the efficiency of gas to additional power compared with the original saturated steam cycle is substantially higher than can be realized by other means, permitting 60-65% net conversion efficiency to be achieved.
[0061] The specific capital cost of the additional capacity of the hybrid plant is comparable with that for a combined cycle gas turbine rather than a conventional power plant or nuclear plant.
[0062] The specific operating and maintenance costs for the cycle are lower than for a comparable combined cycle gas turbine plant as the net capacity is significantly increased for the same gas turbine maintenance costs.
[0063] The higher fuel conversion efficiency and lower specific capital and operations and maintenance costs of the generating capacity enables power to be generated from gas at a significantly lower cost than any available alternative technologies, typically offering output at about 90% of the cost of a conventional combined cycle gas turbine plant with the same cost of fuel.
[0064] Configuration of the integrated steam cycle minimizes the impact of disturbances in the gas turbine cycle, such as gas turbine shutdowns, on the saturated steam plant and enables the saturated steam generator to continue to function normally despite such disturbances. The small effects on the steam generator mean that safety issues related to any nuclear primary circulation through the steam generator are minimized.
[0065] The peak power available from the gas turbine and second steam turbine by the use of additional fuel to reheat the exhaust gases can be delivered independently of operation of the steam generator.
[0066] While outstanding efficiency of the gas turbine cycle is achieved in integrated operation with the steam generator, operation of the gas turbine cycle is maintained at reasonably high efficiency while the steam generator is out of service. Thus the high availability of the gas turbine cycle contributes to revenues while the steam generator is shutdown, e.g. for nuclear plant refueling.
[0067] Start-up and shutdown of either the (nuclear) steam generator or the gas turbine can be accomplished flexibly, simply and with minimum mutual interference, maintaining safety provisions for the nuclear steam system while permitting flexible dispatch of the gas turbine cycle capacity.
[0068] The additional capacity from the gas turbine cycle can be dispatched flexibly according to power demand without significantly affecting the saturated steam plant.
[0069] Breakdown of either the gas turbine plant or the heat supply to the steam generator do not result in a total loss of generated output. The breakdown cases have a predictable loss of output to the electrical transmission network which are the same as the values for the gas turbine, energy recovery heat exchanger and second steam turbine or conventional nuclear plant independently.
[0070] The improved efficiency of fuel conversion results in environmental benefits including reductions of around about 10% of emissions per unit of energy delivered of carbon, sulfur and nitrogen oxides and lower thermal discharges to the environment compared with the best available fossil fueled plant. The additional lower cost generating capacity will displace older more expensive plant with higher emissions, further reducing the overall discharges to the environment.
[0071] The concept can be applied to new power plant or to existing saturated steam cycle plant with similar benefits.
[0072] The design of the heat exchanger zones and the separator are conventional for energy recovery heat exchangers in combined cycle gas turbine power plant so that costs of construction are minimized.
[0073] The enhanced robustness of the gas turbine cycle operation on shutdown of the (nuclear) steam generator increases the integrity of power generation available to support safe reactor operation during the critical shutdown period.
[0074] Transitions of conditions in the heat exchanger are smooth and self-regulating so that operation is simplified and cycle behavior is tolerant of changes in steam cycle or gas turbine conditions.
[0075] The construction of the gas turbine and nuclear plants can be undertaken at different times while permitting operation at up to full capacity but at reduced efficiency prior to completion of the hybrid cycle.
[0076] The design of the steam and water cycle associated with the gas turbine can be designed for maximum independence from the nuclear steam cycle so that interfaces for a retrofit can be minimized and any potential safety case impacts reduced to the lowest possible level.
[0077] The process can deliver a significantly higher fuel efficiency than a conventional combined cycle using the same gas turbine, offering reduced carbon and other gaseous emissions per unit energy production.
[0078] The additional power available to meet demand by the combustion of supplementary fuel is a much larger proportion of gas turbine power than can be achieved by a conventional high efficiency combined cycle plant.
[0079] The specific cost of capacity for the improved process is significantly lower than for the disclosed process in UK Patent GB 2431968A and is lower than or similar to the specific costs applicable to conventional combined cycle power plant.
[0080] The generation capacity of the plant when the steam generator is not available is much increased compared with that offered by a hybrid plant as disclosed in UK Patent GB 2431968A.
[0081] When the steam generator supplies steam at a substantially constant pressure and temperature, the hybrid combined cycle plant can change output upwards or downwards at a rate comparable with gas turbine alone, which is typically an order of magnitude faster than conventional combined cycle power plant is able to offer, in both cases within the permissible rates of change of conditions for the plant components without cyclic life reduction;
[0082] The additional flexibility of the improved process increases the range of roles a plant embodying the process can fulfil within a power system, offering advantages for the system operator and improved opportunities for plant owner to raise revenues for providing additional services to the power system;
[0083] The additional flexibility of the improved process would enable an electricity system to which a plant embodying the process was connected to include a higher proportion of intermittent renewable generation than would be feasible with a conventional combined cycle power plant, thereby reducing carbon dioxide and other gaseous emissions more significantly that for the power plant alone or if a combined cycle plant was used for this duty.
BRIEF DESCRIPTION OF THE DRAWINGS
[0084] Embodiments of the invention will now be more particularly described with reference to the following drawings, in which:
[0085] FIG. 1 shows a flow diagram of a hybrid power generation plant arranged to operate according to an embodiment of a first process of the invention;
[0086] FIG. 2 shows a flow diagram of a hybrid power generation plant arranged to operate according to an embodiment of a first process of the invention, which corresponds to the data in Table 1; and
[0087] FIG. 3 shows a flow diagram of a hybrid power generation plant arranged to operate according to an embodiment of a second process of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0088] Referring to FIG. 1 , gas turbine 150 produces hot exhaust gases which are passed in line 151 through energy recovery heat exchanger 152 . The exhaust flows in turn over heat transfer surfaces with their outlet passes at the side facing the incident hot gases to maintain a near constant temperature difference between the external hot gases and the internal process fluid. The first zone of the heat transfer surface, in contact with the hottest gases, is steam superheater 153 . On leaving the first zone the exhaust gases may be reheated by combustion of a fuel in the burners 157 before flowing through the second zone of the energy recovery heat exchanger 154 .
[0089] The intermediate section of the heat exchanger 154 acts as an evaporator through which water is circulated by pumps (not shown) or by natural convection from separator 135 via lines 133 and 134 . The final heat exchange surface is economizer section 155 which is in two parts. The first heats water directly from condenser 127 of steam turbine 126 , or after passage through one or more feedheaters (not shown), delivering it to deaerator 136 .
[0090] Dissolved gases are removed by vigorous direct contact heating of water droplets by steam in the deaerator 136 . Steam extracted from between stages of steam turbine 126 or other steam source (not shown) is used to heat deaerator 136 .
[0091] One or more pumps 137 delivers feedwater from deaerator 136 at high pressure to the second part of economizer 155 which heats water to flow in part to separator 135 via line 138 with the balance via one or more pumps 136 (optional, according to design) and line 160 to mix with feedwater in line 124 to the steam generator 100 .
[0092] The cool exhaust gases from the energy recovery heat exchanger are finally discharged via stack 156 .
[0093] The steam flows in the cycle are integrated with the conventional steam turbine cycle for steam at close to saturated conditions as follows. Steam at near saturated conditions from steam generator 100 is supplied in line 101 and is divided into three, with a large part flowing in line 102 to wet steam turbine 103 , another part passing in line 125 to mix with steam from separator 135 in line 139 to superheater 153 for heating, while the balance flows in line 108 to moisture separator and reheater 105 .
[0094] The steam heated in superheater 153 in gas turbine heat energy recovery exchanger 152 is delivered at high temperature to secondary steam turbine 126 which exhausts into condenser 127 via line 128 . Condensed water is recovered via line 130 and pump 131 with part flowing via line 132 to mix with the condenser flow from the low pressure steam turbine 111 in line 116 . The balance of the condensed steam flow from pump 131 is delivered to the cold end of the economizer 155 .
[0095] Steam flow through steam turbine 126 is set by inlet valve 129 and is preferably controlled to maintain a constant steam temperature at the outlet of superheater 153 .
[0096] Steam at near saturated conditions flows though the high pressure turbine 103 which exhausts wet steam in line 104 to moisture separator/reheater 105 . Moisture separator 105 removes most of the entrained water droplets, draining them in line 107 to deaerator 106 (via a link not shown in FIG. 1 ), and the steam flow remaining in moisture separator/reheater 105 is reheated. The steam flow through reheater 105 is heated by saturated steam in line 108 from steam generator 100 and/or with bled steam (not shown) from high pressure turbine 103 . The heating steam is condensed in the reheater and the condensed water is returned to the condensate of system high pressure feedheaters 109 via a link not shown in FIG. 1 .
[0097] The steam entering the reheater flows in turn over heat transfer surfaces with their outlet passes at the side receiving the highest temperature fluid from the heat exchanger to maintain a near constant temperature difference between the external steam and internal process fluid.
[0098] Reheated steam from moisture separator/reheater 105 is recovered in line 110 and expanded through low pressure steam turbine 111 . The steam from turbine 111 passes in line 112 to condenser 113 and the condensed water is recovered in line 114 and pumped by pump 115 through one or more low pressure feedheaters 117 to deaerator 106 . Steam extracted from between stages of the steam turbine is used to supply heat to the feedheaters. The water condensed in the feedheaters is cascaded (not shown) to a feedheater at lower temperature or discharged into condenser 113 .
[0099] Dissolved gases are removed by vigorous direct contact heating of water droplets by steam in the deaerator 106 . The heating steam for deaerator 106 is taken either from the exhaust or from between stages of high pressure steam turbine 103 . The water from deaerator 106 is pumped to high pressure by one or more feed pumps 121 and further heated by one or more high pressure feedheaters 109 to a temperature suitable for return to the steam generator 100 in line 124 .
[0100] The high pressure feedheaters are heated with steam extracted from between stages of the steam turbine 103 and with hot water from the condensed heating steam flows to reheater 105 . The steam condensed in the feedheaters and the water flows are cascaded (not shown) to a feedheater at lower pressure and/or to the deaerator 106 .
[0101] FIG. 2 shows a hybrid power generation plant arranged to operate in the same way as described above in connection with FIG. 1 . The reference numerals in FIG. 2 correspond to the points at which the data outlined in Table 1 below are obtained.
[0000]
TABLE 1
Reference
With additional
Condition
heat input
Ref.
kg/s
bara
C.
kg/s
bara
C.
Steam generator output
1
1503
66.3
282
1518
66.8
283
Net main steam flow
3
1291
66.1
280
1501
66.8
283
NuGas ST steam
4
224
60.5
566
224
60.5
566
HRSG evaporator outlet
5
12
65.1
281
206
65.1
281
Evaporator feed
6
12
65.1
278
206
65.1
256
Economiser outlet
7
112
65.1
278
214
65.1
256
Economiser inlet
8
103
3.5
30
184
2.9
29
NuGas ST exhaust
9
222
0.04
30
202
0.04
29
Nuclear ST exhaust
10
627
0.04
27
758
0.04
30
Steam generator feedwater
11
1503
73
222
1519
73
226
Nuclear DA outlet
12
1437
4.7
152
1546
5.6
158
Nuclear DA inlet condensate
13
934
7.0
121
978
7.9
127
Nuclear ST condensate
14
864
14
27
903
15
30
NuGas ST condensate
15
222
3.6
30
202
2.9
29
Nuclear ST MSR Outlet
16
787
4.7
274
933
5.5
272
Nuclear ST HP inlet
17
1222
64.2
280
1429
64.2
280
MSR inlet
18
911
4.9
151
1077
5.8
157
NuGas condensate to Nuclear
19
120
14
30
18
15
30
GT exhaust
20
537
1.04
610
537
1.04
610
HRSG stack
21
537
1.02
88
549
1.02
88
MSR heating steam
22
69
64.2
280
72
64.2
280
HRSG superheater inlet
29
224
65.1
281
224
65.1
281
Nuclear to NuGas transfer steam
31
212
65.5
281
18
66.8
283
HRSG firing gas
32
0
—
—
7.2
2
25
Generator Outputs (MW)
A
808
932
B
227
227
C
291.5
283
[0102] Referring to FIG. 3 , the cycle applied to the plant follows the process and references as described for FIG. 1 except as follows:
[0103] The second stream from steam generator 500 is carried by line 525 to steam heated evaporator 560 . Secondary steam is generated by evaporating the feedwater delivered in line 561 by condensing the incoming flow from line 525 . The secondary steam is supplied by line 562 to the superheater 553 for heating and is delivered at high temperature to steam turbine 526 which exhausts into condenser 527 . Condensed water is recovered via line 530 and delivered by pump 531 as a stream which is divided into two parallel streams for heating and delivery to second deaerator 564 . The first stream is delivered to feedheater 563 while the second part is delivered to the first section of economizer 555 in energy recovery heat exchanger 552 . The heated recovered streams from the feedheater and economizer are mixed and delivered to the second deaerator 564 in line 565 .
[0104] The second deaerator 564 removes dissolved gases from the condensed water using vigorous direct contact heating with steam supplied to the deaerator from the separator 535 or steam turbine extraction (connections not shown for clarity). The resulting hot water, pumped to high pressure by the one or more feed pumps 566 , is divided into two streams. The first stream is delivered to the second section of economizer 555 of the gas turbine energy recovery heat exchanger 552 . The heated recovered stream is further split into a stream to separator 535 via line 538 and a stream in line 536 to optional pump 539 for delivery as feedwater into line 561 . The second stream delivered by the one or more feed pumps 566 is heated in the water to water feedheater 567 and recovered into line 561 . The mixed heated water flow in line 561 is delivered to the steam heated evaporator 560 to generate secondary steam.
[0105] Feedwater supplied to separator 535 is circulated by convection or by pump(s) (not shown) through evaporator section 554 of the energy recovery heat exchanger 552 via lines 533 and 534 . The steam stream from separator 535 is mixed with secondary steam from steam heated evaporator 560 in line 540 .
[0106] The steam flow from line 525 condensed in the steam heated evaporator is recovered via line 568 and divided into two parts. The first part is delivered by pump 569 to mix in line 524 with the heated feedwater from feedheaters 509 to be supplied to the steam generator 500 . The second part is delivered to water to water feedheater 567 where it heats part of the stream from the one or more feed pumps 566 . The recovered cooled part is delivered to feedheater 563 where it heats part of the condensate pumped from the condenser 527 . The cooled condensed stream is reduced in pressure in valve 570 and returned to the main cycle in line 516 .
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Power generation plant and process comprising: providing a steam generator; first, second and third steam turbines; a reheater; a gas turbine; and at least one heat exchanger; supplying feedwater bypassing the steam generator to the heat exchanger and heating the feedwater stream therein by supplying the at least one hot exhaust gas stream from the gas turbine to the heat exchanger; and recovering heated steam from the heat exchanger and supplying at least part of the recovered heated steam stream to the second steam turbine to generate power in the second steam turbine.
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FIELD OF THE INVENTION
The present invention relates to a device for locating and sealing a puncture wound in animal and human tissue and the related method. A particular example is a vascular puncture.
BACKGROUND OF THE INVENTION
An ever increasing number of vascular interventional procedures are being undertaken by cardiologists and radiologists. With the growing use of both diagnostic and therapeutic procedures requiring percutaneous vascular access, a real demand exists for a method and device for accurately locating and closing the puncture site in the blood vessel, post inter-ventional procedure.
Due to ease of access, the most common site selected for these percutaneous arterial inter-ventional procedures is the femoral artery. The normal procedure is to insert an angio-graphic needle into the femoral artery. This is followed by the insertion of a guide wire and over this guide wire successive dilators are passed percutaneously into the artery in order to widen the puncture in the artery sufficiently to allow the sheath of optimal diameter for the diagnostic or therapeutic procedure to be inserted. Through this sheath is then inserted the required catheter or intervengional device in order to perform the required diagnostic or therapeutic procedure on the patient.
At the end of the procedure above, the standard treatment on removal of the sheath involves digital pressure on the artery, supplemented with external compression such as sandbags, pneumatic extension cuffs, or adjustable vice-like devices which may be graduated to apply different degrees of pressure on the skin over the puncture site. This method results in the occlusion of the puncture site by thrombosis of blood in the wall of the puncture site and haemostasis in the percutaneous tract. It causes considerable discomfort for the patient and is associated with a long period of immobilisation. Unpredictable post-procedural haemorrhaging during time periods varying from hours to days after the intervention are not uncommon, and may even be fatal for the patient. The additional healthcare cost in dealing with this complication may be considerable.
A series of devices have been invented to address some of these problems by Datascope Corp. U.S.A., PerClose Corp. U.S.A., Kensey Nash Corp. U.S.A. and Bard Corp. U.S.A.
SUMMARY OF THE INVENTION
The present invention which is, however, independent of the exact procedure and of which type of wound is involved, discloses a new method and a new device for sealing a tissue wall puncture by approximating the walls of the tissue in such a way as to obliterate the puncture site. The present invention will find use for vascular puncture wounds, as well as in other medical procedures which rely on percutaneous access to hollow organs such as laparo-scopic procedures, arthroscopic procedures, and the like. It will also find use in closing body orifices approached directly by the device or approached through body cavities or organs.
The new method involves the use of a surgical stapler which includes means to permit use at visually inaccessible sites.
Accordingly, the invention proposes a surgical stapler having a stapler head at its distal end, comprising guide means which can be used to constrain the stapler to move along a pre-positioned guide wire to reach a location along the path of said guide wire. The invention is of particular use at visually inaccessible surgical sites.
The invention also proposes a surgical stapler, for use at visually inaccessible vascular sites, having a stapler head at its distal end, and comprising guide means which can be used to constrain the stapler to move along a pre-positioned guide wire to reach a location along the path of said guide wire, and locator means which project forwardly of the stapler head which enable blood flow to be sensed within a blood vessel with consequential location of the stapler head adjacent the exterior of said blood vessel.
After the intervention the guide wire may have an incremental marking measurement scale along its length, allowing the operator to estimate precisely the amount of guide wire which is placed within the blood vessel. After the interventional procedure serial dilators may be placed over the guide wire and used to dilate the subcutaneous tract down to the level of the external wall of the arterial puncture to allow access by the stapler. The dilator may contain a radio-opaque marker and also a measurement scale which allows the accurate measurement of the length of the percutaneous tract from the skin level to the outer surface of the blood vessel puncture site.
As an alternative method of locating the puncture accurately, the dilator may have a fine bore plastic tube running through its length which passes over the guidewire. The calibre of this plastic tubing is such that it will be sufficiently small to pass into the blood vessel. This tubing may be fixed to the dilator and protrudes for approximately 1-6 mm and preferably 2-4 mm beyond the distal end of the tissue tract dilator. When blood is observed pulsing back from the distal end of this tubing on to the skin, it can be taken to signify that the tube has entered the blood vessel and consequently the dilator has reached the outer surface of the blood vessel. When this occurs, the exact depth of the percutaneous tract may be measured. Transmission of a a pulsation via the dilator to operator may be taken as further evidence that the dilator is resting against the outer wall of the artery. After completion of dilation of the tract, the dilator is removed over the guidewire which itself is left in place so that the inventive stapler can then be used.
Alternatively, the fine bore tube may be fixed within the stapler itself with the same degree of projection. In either case, the distal end of the tube may have a longitudinal slit into which the guidewire may enter as it curves into the artery.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention shall be clearly understood, exemplary preferred embodiments are now described with reference to the drawings, in which:
FIG. 1 is a schematic view of an apparatus according to the present invention being moved into position;
FIG. 2 is a schematic view of the surgical stapling device which has been brought into position for use over the guide wire and its position may be indirectly confirmed by observing the back flow of blood through the blood vessel puncture site locator tubing;
FIG. 3 is a cross-sectional view of an artery with the guide wire and stapler still in place; and
FIG. 4 is a schematic view in section of the distal end of an apparatus constructed according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A new vascular stapling device is advanced over a guidewire 1 (see FIG. 1) previously inserted. The shaft of the stapling device which may be rigid or flexible slides down along the guidewire through the dilated subcutaneous tissue 4 tract and rests on the wall of the blood vessel 9 . The shaft 6 of the stapling device may be calibrated in order to confirm to the operator that the previously measured length of the tract has been travelled by the shaft. Running through the shaft of the stapling device may be one or two blood vessel puncture site locating flexible plastic tubes 2 , which may be advanced over the guidewire 1 . These tubes may be located in the front and/or behind and/or beside the one or more staples to be delivered to close the puncture site. This plastic tubing may be calibrated and its exact relationship with the tip of the stapling device is known because of calibrated graduated measured markings or other method of marking along its length. In addition this tubing may be radio-opaque further facilitating identifying its position in relation to the puncture site.
As the distal end of the stapling device (FIG. 2) comes to the outer wall of the blood vessel. 9 , an approximate 4 mm protrusion of the blood vessel puncture site locator plastic tubing 2 , 3 may enter through the puncture site 14 into the lumen of the blood vessel 5 . Pulsating blood will then traverse back through the tubing, through the shaft 6 of the stapling device, and out through the proximal lumen of the tubing 2 , 3 . This can be taken as an indication that the tip of the stapling device rests against the outer blood vessel wall 9 at the puncture site 14 . Transmission of a pulsating feeling from artery via stapler to operator may be taken as further evidence that the stapler is resting against the outer wall of the artery. A second plastic tubing 3 which may be located behind the first or second staple may also be advanced into the arterial puncture to confirm exact localization and alignment of the stapler, if so desired.
Following confirmation of the stapler position, the blood vessel locator tubing 2 , may be pulled back along the guide wire 1 into the shaft of the stapler. The pulsation of blood then ceases. At this point the distal end of the stapler which is orientated by the guidewire 1 is now placed firmly against the blood vessel wall 9 . As the shaft 6 of the stapling device is brought towards perpendicular position (see FIG. 2) in relation to the skin 15 , it will result in the guidewire assuming an angle approaching or greater than 90 degrees and this may cause the puncture hole to be stretched and to change from a round shape to become more oblong. This has the effect of bringing the opposite walls closer together. A safety latch on the handle of the stapler is released and graduated pressure is then applied to the handle of the stapler, which results in the two needle sharp legs (see FIG. 3) of one or more separate staples placed in parallel to be deployed simultaneously (or consecutively, if delivery mechanism is so designed) in order to engage the blood vessel wall. In the case where two staples are delivered, the four staple points (two points per staple) are ejected either in the longitudinal or transverse axis (if stapler is rotated 90 degrees) of the blood vessel and their accurate positioning is assisted by the previous measurements described above and by the fact that the staple delivery system is held on a guide wire. The one or more pre-formed staples may be totally deployed into the wall of the blood vessel 9 while at the same time undergoing a predetermined deformation 7 as defined by the shape of the staple former 8 mechanism in the stapler head.
If required, an angiogram may be performed via a side arm on the plastic tubing which traverses the length of the stapling shaft. Contrast medium may be injected into the blood vessel, provided the tubing is advanced along the guide wire and into the blood vessel. Alternatively, the contrast medium may be injected at the outer surface of the blood vessel if so desired in order to reconfirm the exact positioning of staples. Also a radio opaque marker may be present in the tip and shaft of the stapling device and this combined with the radio opaque nature of the staples themselves may facilitate further confirmation that the desired placement has taken place.
The trigger mechanism which advances the single or double staple pushers (which are part of the staple former mechanism 8 ) (see FIG. 4) may be further advanced and this results in one or both staples being further deformed to the desired shape and ejected by the formed shape unload spring 12 from the distal end of the stapler simultaneously (or consecutively if stapler so designed), with the transverse member of each staple perpendicular to the long axis of the blood vessel. Alternatively, they may be discharged in parallel to the long axis of the blood vessel resulting in a transverse closure of the puncture site. Closure of the staples will result in the approximation of the opposite walls of the puncture site. The end result will be a minimum of one staple (preferably two) closing the puncture site by means of deformation of two metal or absorbable staples (or staples made from other non-absorbable implantable material) in such a way as to approximate the walls of the puncture site.
During the final closing action of the staples, the operator may decide whether or not to close the puncture site around the guide wire. Normally, the guide wire will be of sufficiently fine calibre so as to result in minimal subsequent problems of bleeding on its removal. The operator may find it desirable to leave the guide wire in place after deployment of the staple or staples if he believes that there is a danger that the vascular procedure which has been carried out will require a re-intervention within a defined time period. If however, the operator is confident that no subsequent intervention in the immediate post-procedure period will be warranted, the guide wire may be removed prior to the final formation of the staple resulting in the closure of the puncture site. Alternatively, the total procedure of deployment, deformation and ejection of the staple or staples from the stapling device may be carried out in one continuous movement over the guidewire which may be removed immediately after deployment.
Two spring-like or other mechanisms 12 will eject the staples either towards the midline of the stapler shaft or towards the lateral walls of the stapler when the final trigger activation squeeze mechanism has been completed. This will result in releasing the staples from the distal end of the stapler and allow withdrawal of the stapler shaft from the percutaneous tract over the guide wire with ease.
FIG. 4 illustrates another embodiment of an apparatus having a frame and shaft 6 (which may be flexible) which stores at least one surgical staple at its distal portion. The shaft has at least one purposely built hollow channel 10 , 13 (see FIG. 4) running throughout its length which allows the shaft 6 to be advanced over a guide 1 which has previously been placed percutaneously into a blood vessel lumen 5 in order to secure vascular access as previously described for percutaneous intravascular interventions. This purposely built channel (or channels) 10 , 13 may also be used to advance blood vessel puncture site locator tubing 2 , 3 along guidewire or by itself into blood vessel puncture site 14 . The frame and shaft (which has been advanced over the guidewire) house two staple pushing apparatus, each having a staple forming mechanism 8 , which advance the staple or staples into the margins of the puncture site on the outer surface of the blood vessel (see FIG. 3 ). Two anvil means 11 are shown on the distal end of the shaft for closing the staple in a manner that causes the staple to penetrate the wall 9 of the blood vessel. Subsequent deformation of the staple about the anvil 11 will result in the bringing together of the opposite walls of the puncture site. The staple pushing apparatus (of which the staple former 8 may be a part) may extend from the frame through the shaft 6 of the device and may be activated by a trigger mechanism attached to the frame and forming a part thereof.
The surgical staples may be stored in parallel beside each other, with the transverse member of the staple perpendicular to the longitudinal axis of the shaft. The shaft may be rotatable. This point of rotation may begin at the junction between the frame and the shaft. The distal end of the shaft may have a pivoting joint. Throughout the length of the shaft, at least one elongated rod may be positioned within the shaft to act as a pusher to deploy one or preferably two staples simultaneously or consecutively and in parallel while the stapler is positioned over the guide. The means of advancing the staples distally may be controlled by the operator at a proximal location. The distal end of the staple former 8 engages the staple or staples and advances the staple or staples in the distal direction. The staple former which forms the distal end of the staple pusher has at its distal end a plate member, and the plate member may be dimensioned, configured and arranged to engage and advance the staple distally. The staple storage area at the distal end of the shaft includes at least one but preferably two anvils 11 (see FIG. 3) which each engage a staple and deform it to a predetermined configuration.
A surgical staple is adapted to bring together the opposite walls of a puncture site in a blood vessel. The staple may comprise of a length of wire and two perpendicular legs which are joined by a transverse member. These perpendicular legs are sharpened and will penetrate the outer wall of the blood vessel. Deformation of the bridge portion of the staple will result in both legs of the staple deforming in arcuate manner and facing in a direction generally towards the centre of the transverse wire portion. Deformation of the staples occurs over each anvil and results in the shortening of the transverse member which ultimately results in the opposite walls of the puncture site being advanced towards each other. The leg members of the staple are folded in such a manner so as not to interfere with each other. The surgical staple may be made from stainless steel, titanium or any absorbable or non-absorbable implantable polymer, i.e. any suitable metal or non-metal.
On completing the closure mechanism of the stapler handle, the indicator on the handle (if present) may show that the staple closure cycle is complete and on release of the handle, the deforming push rods may retract into the shaft of the stapler. This retraction movement of the push rods may cause a spring 12 or other mechanism on the side of the stapler shaft wall (which was deformed by the advancing staple former) to return to its original shape. This spring-back effect may result in one or both of the fully formed staples being ejected from their housing in the distal end of the stapler. Since the staples are now free of the stapling device nose, the staple device itself may now be easily removed from the percutaneous tract along the guide wire.
The procedure described above may be carried out using a kit comprising of a surgical staple, guide wire, fine bore plastic tubing for performing an angiogram and localizing the position of blood vessel puncture site in relation to the stapler, a dilator with a hollow channel and graduated markings on its outer surface which can be detected radiologically, a connector side arm for the tie bore tubing through which saline or contrast medium may be injected. Components may be supplied as part of a kit or they may be supplied in a blister type or other packaging.
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A surgical stapler for use at visually inaccessible sites comprises a shaft having a stapler head at its distal end and a guide means for accommodating a separate, pre-positioned guide wire whereby the stapler may be slid bodily along the guide wire to guide the stapler head towards the exterior of a blood vessel. A blood vessel locator tube has a forward end projecting forwardly of the stapler head for entering the blood vessel through a puncture site and a rear end remote from the distal end of the shaft. The locator tube allows the positioning of the stapler head at the blood vessel to be indicated by a flow of blood from the rear end of the tube.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is related to our copending patent application having the Ser. No. 440,104, now U.S. Pat. No. 3,914,613, filed concurrently herewith and entitled "Inspection And Repair Apparatus For a Nuclear Reactor Fuel Assembly".
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to nuclear reactor handling apparatus and more particularly to an arrangement for handling a radioactive fuel assembly during dry transfer operations at a reactor site.
2. Description of the Prior Art
In today's commercial nuclear power plants, there exists a requirement to replace the nuclear core at predetermined time intervals, usually on the order of once every year. This involves removal of irradiated fuel assemblies from the core which is located within a reactor vessel, and after an appropriate period of storage in a spent fuel pit, transferring the fuel assemblies from the storage pile into a shipping cask. Since the cask is designed to function additionally as a radiation shield, the cask may be handled with complete safety and without the need for specialized radiation protection equipment. The shipping cask with the irradiated fuel assembly contained within it is sealed and then loaded a truck and shipped off the nuclear reactor site. It is to be noted, that throughout these transfer operations, the irradiated fuel assembly is shielded at all times. The operations whereby the fuel assembly is removed the core and transferred into the shipping cask are all performed underwater which serves as a radiation shield; thereafter, the shipping cask itself serves as a radiation shield.
In the prior art, replacement of the spent fuel assemblies by new fuel assemblies did not usually require the above mentioned radiation protection procedures. This was because new fuel assemblies such as those utilized in boiling water reactors or pressurized water reactors contain enriched uranium oxide which is not radioactive. Therefore, in the prior art, new fuel elements were brought onto the reactor site by truck or rail, were removed therefrom by a crane and then transferred to a new fuel storage pit without being shielded during these operations.
With the increasing availability of fissile Plutonium 239, which is produced as a by-product within water moderated nuclear reactors, and the inherent economic advantages offered by the use of this nuclear fuel, it is certain that new fuel assemblies will contain significant amounts of recycled Plutonium 239. Since this material is highly radioactive in its "natural state," the prior art handling techniques for a new fuel assembly is no longer satisfactory. That is, that all handling operations for new fuel assemblies containing Plutonium 239 must be performed with the fuel assembly being adequately shielded to prevent site personnel from being exposed to highly dangerous radioactivity.
SUMMARY OF THE INVENTION
The aforementioned inadequacies of the prior art are overcome by the present invention which provides apparatus whereby a new but radioactive fuel assembly is shielded during dry transfer operations.
The invention provides a shielding sleeve having grasping and hoisting capabilities integrally associated therewith. In a preferred embodiment, the shielding sleeve comprises an inner sleeve and an outer sleeve with an annulus therebetween filled with radiation shielding material such as water or mineral oil. The length of the shielding sleeve is slightly greater than the length of the fuel assembly to be transferred so that upon being drawn within the shielding sleeve, the radiation level surrounding the outside of the shielding sleeve is low enough to permit direct access by personnel.
The hoisting capability is provided by a conventional gear motor in cooperation with a cable winch to which wire cable is attached. A fuel grasping tool is attached to the free end of the cable; the fuel grasping tool being mounted to operate within the hollow portion of the shielding sleeve. The shielding sleeve may be provided with one or more access plugs to allow for direct access to the fuel grasping tool or the fuel assembly.
In operation, the shielding sleeve is positioned directly above a fuel assembly which is to be transferred in the air environment of a fuel handling building. Connection is made between the fuel grasping tool and the fuel assembly by utilization of the access port in the shielding sleeve. The gear motor is then activated which rotates the cable winch and lifts the fuel assembly up within the shielding sleeve. The fuel assembly is then pinned to the shielding sleeve by a safety shaft so that the fuel assembly is redundantly supported within the shielding sleeve. At this point the shielding sleeve may be attached to a crane and the entire assembly may be dry transferred, that is, not underwater, to another location in complete safety.
BRIEF DESCRIPTION OF THE DRAWINGS
Other advantages of the invention will be apparent from the following detailed description, taken in consideration with the accompanying drawings, in which:
FIG. 1 is a floor plan of a fuel handling building of a nuclear reactor power plant wherein the apparatus as provided by this invention may be utilized;
FIG. 2 is a sectional view of the building of FIG. 1 taken substantially along the line II--II; and
FIG. 3 is a view partially in section of one form of the apparatus as provided by this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Throughout the description which follows, like reference characters indicate like elements in the various figures of the drawings.
The building arrangement depicted in FIGS. 1 and 2 is intended to be typical of the many possible building arrangements which allow for fuel transfer operations at a reactor side. These fuel transfer operations fall within two broad categories. The first category consists of transferring new fuel assemblies from rail cars or trucks to on-site storage areas located within a fuel handling building. The second broad category consists of transferring used or spent fuel assemblies from a spent fuel storage area onto a truck or rail car. Although this specification will be primarily concerned with the former category or the transfer of new fuel assemblies, the invention is not to be thereby limited. Modifications of the apparatus provided herein will be readily apparent to one skilled in the art in the utilization of this invention for the transfer of used radioactive fuel assemblies.
New plutonium recycle fuel assemblies which are highly radioactive, may be brought into a fuel handling building 10 by either rail or truck. Unloading of the vehicle is accomplished at an unloading area 11. Typically, new fuel assemblies will be contained within shipping containers which serve as a radiation shield and prevent the release of highly dangerous radioactivity during transit. The shipping containers 12 are removed from the transport vehicle by an overhead crane 15 which suitably supported on a track or rail 16 which is attached to the fuel handling building 10. The shipping containers are then placed in an area 13 adapted for storage of the shipping containers 12.
The fuel assemblies 20 are up-ended along with a portion of the shipping container in a manner as shown in FIG. 2. Although not at all times essential it is preferable that the up ended portion of the shipping container provides for radiation shielding during this phase of the transfer operation. The fuel assembly is then drawn up within the fuel handling arrangement 21 which is suspended from overhead crane 15 and moved to a new fuel storage area 14. New fuel storage area 14 may be made from concrete and filled with water to provide adequate shielding. Up to this point all the fuel handling and transfer operations are accomplished dry, that is, not underwater. Hence, radiation shielding is provided respectively by shipping container 12, the fuel handling arrangement 21, and the new fuel storage area 14.
Still referring to FIGS. 1 and 2, the new plutonium recycle fuel is then transferred from the new fuel storage area 14 to an inspection station 17 and then to a refueling canal 18 in preparation for reloading a core (now shown) of a nuclear reactor (not shown) located in reactor containment building 19. During transfer of the fuel from the new fuel storage area 14 to the refueling canal 18 and while located at the inspection station, radiation shielding is provided by the fuel handling arrangement 21. As with the prior transfer operations within the fuel handling building 10, these are also accomplished dry which permits direct access by reactor site personnel without the danger of radioactive exposure.
As shown in FIG. 1, a spent fuel storage area 30 is operatively connected to the refueling canal 18. Also, a spent fuel shipping cask storage area 31 is located adjacent the unloading area 11. Hence, the fuel handling arrangement 21 provided by this invention may be readily adaptable for the transfer operations of spent fuel which is also highly radioactive.
Details of one form of the fuel handling arrangement 21 for the transfer of new plutonium recycle fuel assemblies is shown in FIG. 3. An inner sleeve 22 is separated from an outer sleeve 23 by an annulus 24. Each end of annulus 24 is capped by an end plate 25. In a preferred embodiment, sleeves 22 and 23 as well as end caps 25 are made from one-inch stainless steel plate. Annulus 24 is filled with a material such as water, mineral oil, polyethylene or other like radiation shielding material. A preferred size of annulus 24 is such that it comprises a radiation shield equivalent to 6 inches of water. The combination of the sleeves and the annulus will reduce the radiation level from 400 MR/Hr within the interior of sleeve 22 to a level of approximately 2.5 MR/Hr at the outside of sleeve 23. The higher radiation level represents the maximum recycle radiation level of Plutonium 239 which is the material from which the plutonium recycle fuel assemblies are made. The 2.5 MR/Hr radiation level represents an acceptable power limit permitting direct access by reactor site personnel without harm from radiation.
The width of inner sleeve 22 as well as the length of the arrangement 21 is consistent with the maximum length and width of a fuel assembly to be handled by the arrangement. For example, assuming a fuel assembly has a length of 160 inches, and then the length of the handling arrangement 21 should be approximately 180 inches long; and assuming a fuel assembly has a width of 8.5 inches, then the width of inner sleeve 22 should be 12 inches.
An appropriately powered electrical gear motor 30 is connected to a cable winch 31 and is mounted to the end cap 25 such that a cable 32 associated with cable winch 31 is positioned to move within inner sleeve 22. A fuel handling tool 33 is attached to the end of cable 32. Any one of a number of designs of fuel handling tools is satisfactory for use with the arrangement. The type of fuel handling tool 33 shown in FIG. 3 comprises four pivotable latching arms which fit within an opening of a fuel assembly. Although not shown operation of the handling tool 33 is readily envisioned whereby rotation of an actuator 29 causes outward rotation of the latching arms which then lock into position within an opening provided in the fuel assembly. In order to permit insertion of an actuator extension 34, an opening 35 is provided through the lower end of the fuel handling arrangement 21. An access plug 36 is provided for the purpose of sealing hole 35 during such times as when the actuator extension 34 is not being used. Plug 36 is constructed in a manner consistent with the shielding capabilities of the fuel handling arrangement 21. For example, access plug 36 may consist of a steel encasement having a core filled with polyethylene or water or mineral oil.
Raising and lowering of the fuel handling tool 33 is accomplished by means of a pendent control 37 which actuates the gear motor 30 and the cable winch 31 attached thereto. A limit switch 38 which overrides pendant control 37 is provided in the upper end of inner sleeve 22. When a fuel assembly which is being raised comes in contact with limit switch 38, gear motor 30 is automatically stopped to prevent impact of the upper end of the fuel assembly with the cable winch 31. A safety shaft 39 is used to pin a raised fuel assembly to the fuel handling arrangement 21 thereby providing redundant support of the fuel assembly.
The fuel handling arrangement 21 adapted to be suspended from an overhead crane such as crane 15 in FIG. 2. The suspension comprises a Y-shaped spreader 40 and three slings 41 which are capable of pivoting at each end. A load cell 42 is interposed between the crane hook and spreader 40 to indicate whether or not the fuel handling arrangement is being supported by the overhead crane.
In a typical operating sequence of the fuel handling arrangement, fuel handling arrangement 21 is suspended from a crane and positioned directly over a fuel assembly about to be transferred from one location in the fuel handling building 10 to another. The arrangement 21 is lowered to a point where the fuel handling tool 33 is positioned within an opening in the fuel assembly. Access plug 36 is then removed and actuator extension 34 is inserted through the opening 35 and the fuel handling tool 33 is locked into engagement with the fuel assembly. Gear motor 30 is then turned on by pendent control 37 causing rotation of cable winch 31 and lifting of the fuel assembly attached thereto. The fuel assembly is then completely drawn up within the inner sleeve 22 until contact with limit switch 38 is achieved and the gear motor 30 is deactivated. Safety shaft 39 is then slid in place thereby preventing the fuel assembly from being dropped in the unlikely event of failure of either the fuel handling tool 33, the cable 32, or the cable winch 31. The completely shielded fuel assembly may now be transferred within the fuel handling building 10.
It is to be noted that in the transfer of the fuel assembly from a shipping container 12 to the new fuel storage area 14 or from the new fuel storage area 14 to the inspection station 17 and from the inspection station 17 to the refueling canal 18, that the radioactive fuel assembly is being continuously shielded. For example, in FIG. 2 it is seen that as the fuel assembly is lifted out of the shipping container 12 it is being drawn up into the shielded handling arrangement 21. Thus, the invention provides for the dry transfer of a radioactive fuel assembly from one location to another while maintaining a radiation shield which permits direct access thereto by operational personnel.
Since numerous changes may be made in the above described arrangement and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all the matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
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Apparatus is disclosed for handling radioactive fuel assembly during transfer operations. The radioactive fuel assembly is drawn up into a shielding sleeve which substantially reduces the level of radioactivity immediately surrounding the sleeve thereby permitting direct acess by operating personnel. The lifting assembly which draws the fuel assembly up within the shielding sleeve is mounted to and forms an integral part of the handling apparatus. The shielding sleeve accompanies the fuel assembly during all of the transfer operations.
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[0001] This is a Continuation-In-Part of U.S. application Ser. No. 09/661,518 filed on Sep. 13, 2000 which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] This invention relates generally to vehicle hitches and more particularly to a three point quick coupling hitch with an electrically controlled hydraulic lift and fine tuning adjustments for use on the front end of all terrain vehicles or the rigid frame of other vehicles.
[0004] 2. Background Information
[0005] All terrain vehicles are popular recreational vehicles but with appropriate implements attached thereto they can serve as work machines. For example with a blade or bucket attached they can clear snow from walks or driveways or level earth. With grass cutting attachments they can be used to keep large areas neatly trimmed. Implements useable for the instant quick coupling hitch include snow blowers, rotary tilling devices, rotary brushes, seeders, front end mounted trenchers, yard excavators, push blade, box scrapers, reel lawn mower, rotary lawn motor, saw bush cutting systems and boom mowers, post drivers, posthole augers, drawbars with specialty hitch attachments, vacuum systems, fork lifts, platforms, and the like. Changing from one implement to the other of a work vehicle and a recreational vehicle can be time consuming or of sufficient annoyance that one often will not bother changing for recreational purposes of short duration.
[0006] A number of patents are directed to frames for attaching implements to all terrain vehicles (ATV's), or garden tractors for manipulating the attached implement thus indicating a need and various solutions in an attempt to meet that need. U.S. Pat. No. 3,688,847 granted Sep. 5, 1972 to P. Deeter and U.S. Pat. No. 5,329,708 granted Jul. 19, 1994 to M. Segorski disclose implement mounting frames that extend under the frame of the vehicle. This reduces the clearance of the vehicle thus reducing its ability to pass over obstacles. U.S. Pat. No. 5,967,241 granted Oct. 19, 1999 to G. Gross and U.S. Pat. No. 5,615,745 granted Apr. 1, 1997 to G Cross disclose lift mechanisms for the attached implement. The lifts are manually operated and thereby have obvious limitations including requiring dexterity of the operator as well as difficulties in positioning and repositioning the implement. U.S. Pat. No. 5,950,336 granted Sep. 14, 1999 to K. Liebl addresses some of the concerns by providing a mounting frame with an electric lift. The frame is attached to the vehicle by two lever arms and a pin connection for each and is essentially permanently attached to the implement thus making difficult to substitute one implement for another.
[0007] U.S. Pat. No. 5,746,275 granted May 5, 1998 to G. Cross discloses a three point hitch that includes a plurality of pin connected links and an electric lift. The hitch attaches to the axle of the vehicle and therefore extends some distance from where the hitch attaches to the implement. The three point attachment is the connection of the hitch to the implement.
SUMMARY OF INVENTION
[0008] The hitch and lift assembly comprises a rigid, U-shape frame, a hydraulic jack unit, a coupler connecting one end of the hydraulic jack unit to a receiver on the ATV and an adjusting mechanism that connects the other end of the hydraulic jack unit to the U-shaped frame.
[0009] A preferred embodiment provides for a hitch and lift assembly for attaching an implement to a motorized vehicle having a rigid frame with horizontal and/or vertical cross members typically utilized in the support of ATV, garden tractors and the like. The hitch and lift assembly includes a crossbar member as a rigid link selectively adjustably connected to the ATV frame members by “U-clamps” or other means of attachment. The hitch and lift assembly also includes a generally U-shaped frame comprising a pair of elongated tubular members or legs spaced apart, aligned and connected in the front by a cross member near the ends of the legs which are formed having the distal ends define a pair of spaced apart cylindrical sockets opposite the distal ends of the legs being pivotally attached to the ATV or other vehicle frame. A rigid link defining a floating lockable cam provides limited arcuate movement relative to the frame and includes means limiting the arcuate movement. The hitch and lift assembly also includes an electric powered extendible and retractable power driven jack unit connected at one end thereof to said rigid link defining the floating cam. Means for connecting the distal ends of the legs to the motorized vehicle consists of a pair of removable pins cooperatively engaging the implement or apparatus to be lifted.
[0010] Moreover, the hitch and adapter assembly for connecting an implement to the frame of the front end of vehicles such as all terrain vehicle provides a rigid connection with limited motion for reduced vibration operation. The hitch has two spaced apart sockets on a rigid frame that pivotally connects to the vehicle providing a rigid extension thereof. The sockets receive and cooperatively engage respective pins on the implement providing a quick connection. The electrically powered hydraulic cylinder is connected at one end to the frame and the other end connects to the vehicle by a coupler that slip fits into a socket therefore on the vehicle. The frame pivotally connects to the vehicle at two spaced apart positions. There is a coarse and fine adjustment for varying the height and tilt positions of the implement.
[0011] A principal object of the present invention is to provide a simple, robust adjustable front-end quick connect hitch and lift assembly for a vehicle such as a tractor or more particularly an all terrain vehicle, (“ATV”).
[0012] A principal object of the present invention is to provide a hitch as above described that is usable to connect a variety of implements to the vehicle.
[0013] A further principal object of the present invention is to provide a three point hitch for an ATV with a quick connect/disconnect connection to the implement.
[0014] It is another object to provide a floating cam link which includes coarse adjustments, fine adjustments, and means for locking the floating cam into position in order to provide downward pressure via the electric hydraulic jack.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] A better understanding of the present invention will be had upon reference to the following description in conjunction with the accompanying drawings in which like numerals refer to like parts throughout the several views and wherein:
[0016] FIG. 1 is a side oblique view of an all terrain vehicle with a blade attached thereto by a hitch and lifting assembly provided in accordance with the present invention;
[0017] FIG. 2 is an exploded, oblique view of the hitch and lifting assembly shown in FIG. 1 ;
[0018] FIG. 3 is an exploded top plan of the hitch and lifting assembly;
[0019] FIG. 4 is an exploded view of the hitch and lifting assembly taken essentially along line 4 - 4 of FIG. 3 ;
[0020] FIG. 5 is an alternate embodiment of the present invention showing an exploded, oblique view of the hitch and lifting assembly and the receiver mounted to the crossbar;
[0021] FIG. 6 is an alternate embodiment of the present invention showing an exploded, oblique view of the hitch and lifting assembly and the relocation of the cam lock secured to the top of the cam link and extending over the top edge of the lugs on each side thereof providing means for locking the floating cam and exerting downward pressure via the hydraulic jack; and
[0022] FIG. 7 is an exploded view of the hitch and lifting assembly taken essentially along line 4 - 4 of FIG. 3 , wherein the cam lock is secured to the top of the cam link by a knob and threaded stud including a bracket extending over the top edges of the lugs for locking the floating cam.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] Referring to the drawings there is illustrated a conventional all terrain vehicle (ATV) 10 with a blade 20 attached to the front thereof by a hitch 30 provided in accordance with the present invention. The blade 20 maybe used to clear snow or move earth and is by way of example of an implement attachable to the vehicle. Of course, it is contemplated that any implement set forth heretofore could be substituted for the blade 20 . The ATV has an open protective rigid grill 12 on the front comprising a weldment of a pair of generally vertical tubular members 13 as shown in FIG. 2 which is a typical arrangement for tubing members forming a part of the ATV frame. The grill 12 is part of the vehicle 10 and is rigidly attached to and forms a part of the vehicle frame. Means for holding such as a pair of “U” clamps 15 attach a horizontally disposed longitudinal crossbar 16 to the two vertically disposed tubular frame members 13 that are part of the rigid grill 12 . The crossbar 16 has a means for pivotally detachable engagement defining a threaded hole 17 in opposing distal ends thereof, each one for receiving one of a pair of hitch mounting bolts 19 thereby pivotally connecting a frame portion of the hitch supported by the tubular frame members 13 to the vehicle 10 .
[0024] The hitch and lift assembly 30 comprises a rigid, U-shape frame 31 , a hydraulic jack unit 32 , a coupler 33 connecting one end of the hydraulic jack unit 32 to a receiver 18 on the ATV and an adjusting mechanism 34 that connects the other end of the hydraulic jack unit 32 to the U-shaped frame 31 .
[0025] The receiver 18 is a rectangular or square shaped socket attached to a horizontal or vertical lower frame member of the ATV and conventionally is used for trailer couplings. Alternately, a receiver plate 40 as shown in FIG. 5 connecting to and extending upward perpendicular to the receiver 18 having means for attachment such as holes therein can be attached to the crossbar 16 by aligning the holes therein and inserting bolts therethrough. It is contemplated that the receiver 18 and corresponding sized and shaped coupling 33 can be any selected size and shape, and that the receiver 18 could be connected to the hitch and lift assembly 30 and the coupler could be connected to the frame of the ATV. In the preferred embodiment, the receiver 18 is located on the vehicle at an elevation thereon lower than where the crossbar 16 is located on the grill. The receiver 18 and the bolts 19 cooperatively engaging the two threaded holes 17 in the distal end crossbar provide a three point connection of the hitch 30 to the vehicle 10 .
[0026] As shown in FIG. 5 , the cross member 16 includes as an option one or more vertical holes 83 therethrough. The receiver 18 includes one or more holes through the top surface. A knob 80 having a stud 82 extending therefrom can be disposed through a hole 83 in the cross member 16 so that the stud extends downward through a threaded hole 84 in the receiver 18 for cooperative engagement with the coupler 33 to secure the coupler in fixed position to reduce play and increase structural support and rigidity of the hitch and lift assembly.
[0027] The rigid U-shaped frame 31 comprises a pair of spaced apart parallel elongate tubular members 31 A interconnected adjacent one end thereof by a cross member 31 B, and having the distal ends 42 crimped substantially flat forming a lug 31 C at the distal ends having a through hole 31 D alignable with the horizontally disposed longitudinal crossbar 16 . The distal ends 44 of tubular members 31 A remain open providing cylindrical sockets 31 E for receiving respective pair of pins 21 or short support members secured to and projecting from the implement such as a blade 20 . The blade 20 or other implement of the preferred embodiment uses pins 21 having horizontal holes therethrough for mounting in alignment with holes disposed within a pair of mounting brackets 46 formed by aligning spaced apart flanges 48 connected to the back of the blade 20 . The pins 21 may be rigidly connected to the mounting brackets 46 , or pivotally connected thereto by bolts cooperatively engaging the flanges 48 and pins 21 . In the preferred embodiment, the tubular member 31 A is reinforced by an annular collar 31 F. Each pin 21 has an annular groove 22 that cooperates with a knob and screw 31 G threaded into a threaded fitting insert 50 formed in one or more selected positions along the top of the tubular member 31 A to lock the implement to the hitch and lift assembly 30 . The groove 22 and threaded knob are in alignment when the pin 21 is fully inserted into the cylindrical socket 31 E.
[0028] It is readily apparent the blade 20 implement can be quickly connected and disconnected respectively simply by hand tightening or loosening, as the case maybe, the two knobs with screws 31 G. This makes it easy to switch from one vehicle function to another or from one implement to another and all that is necessary is that the various implements have two parallel pins 21 secured thereto corresponding in size and spacing to the two sockets 31 E provided by the tubular members 31 A. Obviously locking pins or other means of holding in aligned notches or holes can be substituted for the knob and screw implement lock 31 G.
[0029] As best shown in FIG. 3 , the longitudinal tubular members 31 A are pivotally attached to the crossbar 16 by respective ones of a pair of threaded mounting bolts 19 on which there is an outer thrust bushing 19 A and an inboard support bushing 19 B. The support bushing 19 B has a sleeve portion 19 C that slip fits into the hole 31 D in the lug 31 C and it is lubricated via grease fitting 31 H.
[0030] The coupler 33 is Z-shaped having a first generally horizontal short distal end member 33 A corresponding in cross-sectional outline shape to the socket of the receiver 18 for slip fit therein. A generally vertical center section member 33 H is rigidly attached to the distal end member 33 A and extends downwardly a selected distance and is pivotally connected to a second distal end member 33 B. The opposing end of the second distal end member 33 B is a U-shaped portion for pivotally receiving a lower end connecting mount of a hydraulic cylinder 32 A of the hydraulic jack unit 32 . The hydraulic jack 32 of the preferred embodiment is electric; however, it is contemplated that pressured fluid or air from a hydrostatic system or pump, respectively, could be used to actuate the hydraulic jack. Moreover, it is contemplated that a rack and pinion assembly can be substituted for or used with the hydraulic jack, although it is less efficient and more bulky. A pin 32 E connects the cylinder 32 A to the opposing end of the second distal end member 33 B of the coupler 33 by alignment and cooperative engagement of holes formed within the distal end member 33 B and cylinder 32 A. The distal end of the piston rod of the hydraulic jack unit 32 includes a connecting yoke having a hole therethrough for pivotally connecting to the corresponding aligned yoke holes of the adjusting mechanism unit 34 by a pin 32 D.
[0031] The unit 32 includes the above mentioned hydraulic cylinder and to power the same there is an electric motor 32 B drivingly connected to a hydraulic pump 32 C. A control and power cable 32 J extends from the motor 32 B and connects to a control switch 52 conveniently located on the handle bar in close proximity to the hand grip, and is also connected to the power supply on the vehicle 10 .
[0032] The adjusting mechanism 34 includes a first coarse adjusting means 54 and a second fine adjusting means 56 . The coarse adjusting mechanism 54 includes a floating cam or link 34 A pivotally connected at one end by the pin 32 D to the distal end or yoke of the piston rod of hydraulic jack unit 32 and the other end of the link 34 A projects between a pair of lugs 34 B defining projections or mounting plates rigidly anchored to and projecting from the frame cross member 31 B. The lugs 34 B have a series of holes 34 C for selectively adjusting the angle and distance of the piston rod pivotally connecting thereto. A bolt or pin 34 D passes through one of the holes and a hole in the link 34 A providing a loose connection. With this loose connection there is relative movement between the lugs 34 B and the link 34 A and such motion is pivotal movement of the respective members about the pin 34 D. The pin 34 D is lubricated via a grease fitting.
[0033] A cam lock arm 34 E is notched at one end as indicated at 34 F and the other end overlaps one of the lugs 34 B. A shaft 34 G passes through a hole in the lock arm 34 E intermediate the ends thereof and is threaded into a threaded bore in the link 34 A. A hand grip knob 34 H on the shaft 34 G provides means to manually lock and unlock the cam of link 34 A by turning the knob to increase or decrease, as the case maybe, the frictional grip of the lock arm 34 E on the lug 34 B.
[0034] Alternately, the knob and stud 34 H can be disengaged from the vertical threaded bore of the floating cam link 34 A. The cam lock 34 E can be removed therefrom. A threaded bore 60 can be formed in the top of the floating cam link 34 A whereby the cam lock 34 E can be disposed horizontally across the top edge of the lug 34 B and secured thereto with the knob and stud 34 H to create a positive lock for creating down pressure for selected applications.
[0035] The fine adjusting mechanism 56 comprises a stud 34 H threaded into a vertically threaded hole 34 J adjacent an end of the link 34 A and foot plate 34 K on the end of the stud 34 H bears against the longitudinal cross member 31 B. A hand grip knob 34 L provides means to manually turn the stud 34 H providing the fine adjustment. A lever 34 M threaded on the stud 34 H is used to lock the stud 34 H in position, by binding against the link 34 A, at the desired position.
[0036] FIG. 6 shows the relocation of the cam lock 34 E secured to the top of the cam link 34 secured thereto by a knob and threaded stud 70 cooperatively engaging a threaded bore 72 drilled into the top of the cam link 34 and having a bracket 73 extending over the top edges of the lugs 34 B on each side thereof providing means for locking the floating cam 34 and for exerting downward pressure via the hydraulic jack unit 32 .
[0037] The hitch and lift assembly of the present invention can be utilized with any type of vehicle as a coupling hitch include snow blowers, rotary tilling devices, rotary brushes, seeders, front end mounted trenchers, yard excavators, push blade, box scrapers, reel lawn mower, rotary lawn motor, saw bush cutting systems and boom mowers, post drivers, posthole augers, drawbars with specialty hitch attachments, vacuum systems, fork lifts, platforms, and the like. Although it is possible to utilize such the present device in place of a hydraulic unit of a tractor or the like, the advantages exhibited by the instant invention are better realized when utilized on the front end of a vehicle utilizing the electric hydraulic jack providing a compact, quick disconnect lifting device independently of high pressure hydraulic fluid systems.
[0038] The foregoing detailed description is given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom, for modifications will become obvious to those skilled in the art based upon more recent disclosures and may be made without departing from the spirit of the invention and scope of the appended claims.
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A hitch and adapter assembly for connecting an implement to the front end of vehicles such as all terrain vehicle providing a rigid connection with limited motion for reduced vibration operation. The hitch has two spaced apart sockets on a rigid frame that pivotally connects to the vehicle providing a rigid extension thereof. The sockets receive and cooperatively engage respective pins on the implement providing a quick connection. An electrically powered hydraulic cylinder is connected at one end to the frame and the other end connects to the vehicle by a coupler that slip fits into a socket therefore on the vehicle. The frame pivotally connects to the vehicle at two spaced apart positions. There is a coarse and fine adjustment for varying the height and tilt positions of the implement.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates electronic licensing, and more specifically the authentication of software licensure in a computer network environment.
[0002] Computer networks facilitate collaborative efforts of several individuals remotely disposed from one another. Typically, a computer network includes a plurality of users employing client computers communicating with one or more remote server computers to transfer data therebetween and allow access to one or more software programs. Computer networks, however, have presented a challenge with ensuring that the license rights associated with software programs are adhered to. For example, in a non-networked environment, ensuring that the license rights are adhered to is typically accomplished on a user-by-user basis. To that end, the license rights are based upon the number of physical copies of a computer software program (e.g., application, operating system, etc.) purchased by the user.
[0003] In a networking environment, however, the number of users authorized to access a software program may be independent of a number of physical copies of the software program. For example, one physical copy of a software program may be licensed for use by multiple users. As a result, the licensing rights of the software program may be defined in a variety of manners. One copy of a software program accessed over a computer network may be licensed for a certain number of users, or a certain number of terminal connections, or both.
[0004] A typical prior art example of software license management over a network is discussed with respect to FIG. 1 and includes a server 10 and a client 20 . Server 10 and client 20 are in data communication over a network to facilitate execution of a license confirmation program. Upon client 20 's request to access a software program, a license confirmation request program is executed. This license confirmation request program transmits a license confirmation request as well as a license information file that client 20 transmits to server 10 . Upon receipt of the confirmation request, server 10 executes a standby license confirmation program that authenticates the operational environment by referring to the license information file transmitted from client 20 . Server 10 transmits the confirmation result to the client 20 through the network. Were client 20 authenticated, server 10 permits access by client 20 to the software program.
[0005] A drawback with the aforementioned license authentication is that the license confirmation program may be unavailable due to excessive data traffic between server 10 and other users (not shown) or failure of server 10 .
[0006] U.S. Pat. No. 6,023,766 to Yamamura discloses a software license control system that reduces problems associated with excessive data traffic by incorporating license authentication by electronic mail. To that end, the software license control system includes software execution equipment that executes installed software, and software license control equipment that controls the license for the software. The software license control system is characterized by interchanging information on the license for software between the software execution equipment and the software license control equipment by means of electronic mail. Thus, according to the software license control system and software license control equipment of the invention, the information on a license for software is interchanged between the software execution equipment and the software license control equipment by means of electronic mail.
[0007] A need exists, however, to provide license authentication when presented with a catastrophic failure of a licensing software program.
SUMMARY OF THE INVENTION
[0008] The present invention provides a method, computer product and a network to manage software licensing over a distributed network using a master license compliance software program and multiple copies of license compliance software programs. The master license compliance program and the multiple copies define a plurality of the license compliance software programs, each of which has software license rights associated therewith. Referral priority levels are associated with each of the plurality of license compliance software programs to define a referral sequence. The master license compliance program receives a license request and refers the license request to the multiple copies of license compliance software programs. The request is transmitted in accordance with the referral sequence to obtain license authorization, were the master license compliance program to fail to grant the request.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is a plan view of a prior art licensing management system;
[0010] [0010]FIG. 2 is a simplified plan view of a computer network in which the present invention is implemented;
[0011] [0011]FIG. 3 is a block diagram of a client terminal shown in FIG. 2;
[0012] [0012]FIG. 4 is a flow diagram of a method to manage software licenses in accordance with one embodiment of the present invention;
[0013] [0013]FIG. 5 is a flow diagram of a method to process multiple license requests in accordance with another embodiment of the present invention; and
[0014] [0014]FIGS. 6 a and 6 b are flow diagrams of a method to process multiple license requests in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Referring to FIG. 2, shown is a plurality of servers 25 a , 25 b , 25 c and 25 d accessible by client terminals 26 a , 26 b and 26 c over a network 27 . Communication between servers 25 a , 25 b , 25 c and 25 d and client terminals 26 a , 26 b and 26 c may be over a public network, such as a public switched telephone network, over ASDL telephone lines or large bandwidth trunks, such as Tl or OC3 service. Alternatively, client terminals 26 a , 26 b and 26 c may communicate with servers 25 a , 25 b , 25 c and 25 d over a local area network. In the present example, the invention is discussed with respect to communication over a network employing Ethernet protocols. To facilitate communication over network 27 , client terminals 26 a , 26 b and 26 c execute application specific software, to produce a user interface, shown more clearly in FIG. 3.
[0016] Referring to FIGS. 2 and 3, each of the client terminals 26 a , 26 b and 26 c includes one or more system buses 28 placing various components thereof in data communication. For example, a microprocessor 29 is placed in data communication with both a read only memory (ROM) 30 and random access memory (RAM) 31 via system bus 28 . ROM 30 contains among other code, the Basic Input-Output System (BIOS) that controls basic hardware operation such as the interaction with peripheral components, e.g., disk drives 32 and 33 , and keyboard 34 .
[0017] RAM 31 is the main memory into which the operating system and application programs are loaded and affords at least 32 megabytes of memory space. A memory management chip 36 is in data communication with system bus 28 to control direct memory access (DMA) operations. DMA operations include passing data between the RAM 31 and the hard disk drive 32 and the floppy disk drive 33 .
[0018] Also in data communication with system bus 28 are various I/O controllers: a keyboard controller 38 , a mouse controller 40 , a video controller 42 , and an audio controller 44 , which may be connected to one or more speakers 45 . Keyboard controller 38 provides a hardware interface for keyboard 34 , and mouse controller 40 provides a hardware interface for a mouse 46 , or other point and click device. Video controller 42 provides a hardware interface for a display 48 . A Network Interface Card (NIC) 50 enables data communication over the network facilitating data transmission speeds up to 1000 megabytes per second. The operating system 52 of the client terminal 26 may be UNIX, LINUX, DOS, WINDOWS-based or any known operating system.
[0019] User interface, which in the present example is a graphics driven interface referred to as a (GUI) 54 , is loaded in RAM 31 to facilitate running application specific software stored on one of servers 25 a , 25 b , 25 c or 25 d . For example, GUI 54 may facilitate access to a software tool employed to design integrated circuits, such as a Composer Tool available from Cadence Design Systems and is stored on one of servers 25 a , 25 b , 25 c or 25 d.
[0020] Access to the software tool by client terminal 26 a , 26 b and 26 c requires compliance with a license for use of the software tool. To ensure compliance, client terminal 26 a transmits a license request to a master license compliance software program that may be stored on one or more of servers 25 a , 25 b , 25 c and 25 d . In response to the license request, the master license compliance software program stored, for example, on server 25 b , executes and determines whether the request is within the scope of the license that defines the access rights to the software tool. For example, the master license compliance software program may determine whether the amount of clients 26 a , 26 b and 26 c authorized to access the software tool concurrently has been exceeded. Were the number of clients 26 a , 26 b and 26 c accessing the software tool not found to exceed a maximum number, the master license compliance software transmits a grant access command as well as a license information file to client terminal 26 a . Client terminal 26 a then transmits the same to server 25 a upon which the software tool is stored. Upon receipt of the grant access command, server 25 a authenticates the grant access command by referring to the license information file transmitted from client terminal 26 a . Server 25 a transmits the confirmation result to client terminal 26 a through network 27 and allows access to the software tool. Were the master license compliance software to fail to transmit a grant access command to client terminal 26 a , client terminal 26 a would not be provided access to the software tool on server 25 a.
[0021] The present invention, however, takes advantage of the network over which client terminal 26 a communicates with servers 25 a , 25 b , 25 c and 25 d to search out grant access commands from other license compliance programs in communication with client terminals 26 a , 26 b and 26 c over network 27 . To that end, one embodiment of the present invention employs the light-weight directory protocol LDAP to access license information stored on one or more of servers 25 a , 25 b , 25 c and 25 d . Employing LDAP, advantage is taken of the referral features of the protocol by referring a license request, for which no grant access command is received in response thereto, to other license compliance programs that may be placed in data communication with client terminal 26 a over network 27 . These other license compliance programs are named referred license compliance programs, because they receive license requests referred thereto by client 20 as a result of the master license compliance program failing to transmit a grant access command.
[0022] Specifically, the referred license compliance programs are stored on servers other than the server upon which the master license compliance program is stored. The servers upon which the referred license compliance programs are stored may be disposed remotely from each other, as well as from the server upon which the master license compliance program is stored and the client terminal.
[0023] Referring to FIGS. 2 and 4, in an exemplary license management technique, the master license compliance program is stored on a master server, such as server 25 b at step 100 . The referred license compliance programs are stored on servers 25 a , 25 c and 25 d , at step 102 . At step 104 , a license request, generated by client terminal 26 a , is received by master server 25 b . At step 106 , it is determined whether client terminal 26 a received a grant access command. Were a grant access command received by client terminal 26 a , then access to the software tool is allowed at step 108 . Were the client terminal 26 a to fail to receive a grant access command, then client terminal 26 a determines whether there are additional referred license compliance programs from which a grant access command may be obtained, at step 110 . Were it determined, at step 110 , that there were no additional master license compliance programs to which to transmit a license request, then a warning is generated at step 112 . The warning may be generated at client terminal 26 a and may contain audio stimuli, visual stimuli, or both. Were it determined that there were additional referred license programs to which a license request could be transmitted at step 110 , then client terminal 26 a executes a referral subroutine that generates a referral command, at step 114 . After the referral command has been generated, the technique returns to step 106 . Steps 106 , 110 and 114 are repeated until access to the software tool has been granted at step 108 , or a warning is generated at step 112 . In this manner, referral subroutine sequentially transmits a license request to the referred license compliance program contained on each of servers 25 a , 25 c and 25 d . The sequence in which servers 25 a , 25 c and 25 d receive a license request is dictated by the priority level associated with the referred license compliance program, defining a referral sequence. To that end, the referral subroutine contains information concerning the location of the referred license compliance programs, as well as a priority level associated with each.
[0024] In one example, client terminal 26 a may transmit a license request to the license compliance program with the highest priority level first. Were server 25 b to determine that the maximum number of users had been reached for the software tool, server 25 b transmits a denied access command, indicating that no access could be granted. In response to the denied access command, client terminal 26 a proceeds to transmit a license request from the license compliance program having the next highest level of priority. This process continues until a license grant access command is received. Were a request sent to each of the referred license compliance programs in the referral sequence and client terminal 26 a fails to receive a grant access command, a warning would be provided at the client terminal 26 a.
[0025] As stated above, servers 25 a , 25 b , 25 c and 25 d may be disposed remotely from each other, as well as from clients 26 a , 26 b and 26 c . To that end, servers 25 a , 25 b , 25 c and 25 d may have different geographical, organizational, political associations or a combination thereof. Depending upon the geographical definitions, servers 25 a , 25 b , 25 c and 25 d may have a common geographical association by being contained in a common building, a common room within a building and the like. Alternatively, servers 25 a , 25 b , 25 c and 25 d may have differing geographical associations by being located in differing buildings or in differing rooms of a common building. Similarly, depending upon the organizational definitions, servers 25 a , 25 b , 25 c and 25 d may have a common organizational association by being associated with a common company, or a common subunit within a company. Alternatively, servers 25 a , 25 b , 25 c and 25 d may have differing organizational associations by being associated with differing companies or with differing subunits of a common company. Depending upon the definition of political associations, servers 25 a , 25 b , 25 c and 25 d may have a common political association by being contained in a common nation, or a common political subdivision of a common nation. Alternatively, servers 25 a , 25 b , 25 c and 25 d may have differing political associations by being associated with differing nations or within differing political subdivisions of a common nation.
[0026] The priority level associated with each of servers 25 a , 25 b , 25 c and 25 d may be dependent upon any of the aforementioned geographical, organizational and political associations. For example, client terminal 26 a could choose to refer a license request to the server that is positioned the shortest distance from client terminal 26 a . To that end, client terminal 26 a would transmit a license request to the server having a geographical association indicating that it is the shortest distance away. It should be understood, however that the priority levels associated with servers 25 a , 25 b , 25 c and 25 d may be based upon any criteria desired. For example, client terminal 26 a could transmit a license request to the closest server that has an organizational association that is common with client terminal 26 a , independent of the server's distance from client terminal 26 a.
[0027] In addition to priority levels defined by the aforementioned geographical, organizational and political associations, the priority levels may be based upon other parameters, as well, such as the operational parameters associated with the server 25 a , 25 b , 25 c , and 25 d . For example, a server 25 a , 25 b , 25 c and 25 d may be provided with a highest priority level, independent of the geographical, organizational or political association of the same, because the server provides the fastest data access rate, or the greatest number of access connections when compared with all other servers in data communication over network 37 .
[0028] Another embodiment of the present invention takes advantage of the replica features associated with the LDAP protocol to process license requests in the face of a catastrophic failure of the master license compliance program. To that end, created are additional copies of the master license compliance program referred to as replica license compliance programs. The replica license compliance programs are stored on servers other than the server upon which the master license compliance program is stored. The servers upon which the replica license compliance programs are stored may be disposed remotely from each other, as well as from the server upon which the master license compliance program is stored and the client terminal.
[0029] Referring to FIGS. 2 and 5, in another exemplary license management technique, the master license compliance program is stored on a master server, such as server 25 b at step 200 . At step 202 , replica license compliance programs are stored on servers other than master server 25 b , such as servers 25 a , 25 c and 25 d . At step 204 , a license request, generated by client terminal 26 a , is received by master server 25 b . At step 206 , it is determined whether client terminal 26 a failed to receive a grant access command. Were the grant access command received, then access to the software tool would be provided at step 208 . Otherwise, the technique would proceed to step 210 and client terminal 26 a determines whether there are any remaining replica license compliance programs from which to obtain a grant access command. Were there none, then at step 212 a warning is generated by client terminal 26 a , as discussed above. Otherwise, at step 214 , client terminal 26 a executes a replica referral subroutine to generate a referral command. After the referral command has been generated, the technique returns to step 206 . Steps 206 , 210 and 214 are repeated until access to the software tool has been granted at step 208 , or a warning is generated at step 212 . In this manner, the referral subroutine may sequentially transmit a license request to the referred license compliance program contained on each of servers 25 a , 25 c and 25 d . The sequence in which servers 25 a , 25 c and 25 d receive a license request may be defined as stated above with respect to FIGS. 2 and 4. An advantage with this technique is that it enables the processing of license requests in the face of catastrophic failure of the master license compliance program due, for example, to corruption of the master license program or failure of server 25 b.
[0030] Referring to FIGS. 2, 6 a and 6 b , yet another exemplary license management technique in accordance with the present invention, the license management techniques set forth above are combined. This maximizes the availability of license rights available over network 27 in view of catastrophic failure of a master license compliance program or the exhaustion of rights under the same. To that end, at step 300 , a client terminal, such as client terminal 26 a transmits a license to the master license compliance program to obtain access to a software tool. At step 302 , client terminal 26 a determines whether a predetermined amount of time has lapsed since the license request was transmitted, without receiving a command from the master license compliance program. Were this not the case, the technique proceeds to step 304 , wherein client terminal 26 a determines whether a grant access command has been received. Were this the case, then the technique proceeds to step 306 and client terminal 26 a is granted access to the software tool. Otherwise, client terminal 26 a determines whether a deny access command has been received from the master license compliance program at step 310 . Were a deny access command not received, the technique would return to step 302 . Otherwise, the technique would continue to step 312 , wherein client terminal 26 a determined whether there are additional master license compliance programs to which a license request can be transmitted. If not, the technique proceeds to step 314 wherein client terminal refers a license request to a replica license compliance program.
[0031] Were there additional master license compliance programs to which a license request could be transmitted, then at step 316 , client terminal 26 a refers the license request thereto. At step 318 , client terminal 26 a determines whether a predetermined amount of time has lapsed since the license request to the additional master license compliance program was transmitted, without receiving a communication from the master license compliance program. Were this not the case, the technique proceeds to step 320 , wherein the client terminal determines whether a grant access command has been received. Were this the case, then the technique proceeds to step 306 and client terminal 26 a is granted access to the software tool. Otherwise, client terminal 26 a determines whether a deny access command has been received from the master license compliance program at step 322 . Were a deny access command not received, the technique would return to step 318 . Otherwise, the technique would continue to step 312 .
[0032] At step 314 , the license request from client terminal 26 a is transmitted to a replica master compliance program. This may be in response to a predetermined amount of time lapsing since the license request was transmitted to the master server 25 b , at step 302 . Alternatively, step 314 occurs in response to there being no additional master license compliance program wherein client terminal 26 a determined whether there are additional master license compliance programs to which a license request can be transmitted, at step 312 .
[0033] At step 324 , client terminal 26 a determines whether a predetermined amount of time has lapsed since the license request was transmitted, without receiving a command from the replica license compliance program. Were this not the case, the technique proceeds to step 326 , wherein the client terminal determines whether a grant access command has been received. Were this the case, then the technique proceeds to step 306 and client terminal 26 a is granted access to the software tool. Otherwise, client terminal 26 a determines whether a deny access command has been received from the replica license compliance program at step 328 . Were a deny access command not received, the technique would return to step 324 . Otherwise, the technique would continue to step 330 , wherein client terminal 26 a determined whether there are additional replica license compliance programs to which a license request can be transmitted. Were there no additional replica license compliance programs, then the technique would proceed to step 332 and a warning would be generated by client terminal 26 a . The warning would indicate that access to the software tool could not be granted, because no license rights were available.
[0034] Were it determined, at step 330 , that there were additional replica license compliance programs available, the technique would continue to proceed to step 334 , where the license request would be referred to the additional replica license compliance programs. Thereafter, at step 336 , client terminal 26 a determines whether a predetermined amount of time has lapsed since the license request was transmitted, without receiving a command from the replica license compliance program. Were this the case, the technique would return to step 330 . Otherwise, the technique proceeds to step 338 , wherein the client terminal determines whether a grant access command has been received. Were a grant access command received by client terminal 26 a , then the technique proceeds to step 306 and client terminal 26 a is granted access to the software tool. Otherwise, client terminal 26 a determines whether a deny access command has been received from the replica license compliance program at step 340 . Were a deny access command not received, the technique would return to step 336 . Otherwise, the technique would continue to step 330 .
[0035] Although the foregoing has been discussed with respect to managing software license, it should be understood that the present invention may be employed to manage access to any type of software over a network. Thus, the embodiments of the present invention described above are exemplary and the scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.
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Provided are a method, a computer product and a network to manage software licensing over a distributed network using a master license compliance software program by creating multiple copies of the license compliance software programs. The master license compliance program and the multiple copies define a plurality of the license compliance software programs, each of which has software license rights associated therewith. Referral priority levels are associated with each of the plurality of license compliance software programs to define a referral sequence. The master license compliance program receives a license request and refers the license request to the multiple copies of license compliance software programs. The request is transmitted in accordance with the referral sequence to obtain license authorization, were the master license compliance program to fail to grant the request.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of priority to U.S. Provisional Application 61/304,235 filed Feb. 12, 2010, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention relates generally to catheter control systems and methods for stabilizing images of moving tissue regions such as a heart which are captured when intravascularly accessing and/or treating regions of the body.
BACKGROUND OF THE INVENTION
Conventional devices for accessing and visualizing interior regions of a body lumen are known. For example, various catheter devices are typically advanced within a patient's body, e.g., intravascularly, and advanced into a desirable position within the body. Other conventional methods have utilized catheters or probes having position sensors deployed within the body lumen, such as the interior of a cardiac chamber. These types of positional sensors are typically used to determine the movement of a cardiac tissue surface or the electrical activity within the cardiac tissue. When a sufficient number of points have been sampled by the sensors, a “map” of the cardiac tissue may be generated.
Another conventional device utilizes an inflatable balloon which is typically introduced intravascularly in a deflated state and then inflated against the tissue region to be examined. Imaging is typically accomplished by an optical fiber or other apparatus such as electronic chips for viewing the tissue through the membrane(s) of the inflated balloon. Moreover, the balloon must generally be inflated for imaging. Other conventional balloons utilize a cavity or depression formed at a distal end of the inflated balloon. This cavity or depression is pressed against the tissue to be examined and is flushed with a clear fluid to provide a clear pathway through the blood.
However, many of the conventional catheter imaging systems lack the capability to provide therapeutic treatments or are difficult to manipulate in providing effective therapies. For instance, the treatment in a patient's heart for atrial fibrillation is generally made difficult by a number of factors, such as visualization of the target tissue, access to the target tissue, and instrument articulation and management, amongst others.
Conventional catheter techniques and devices, for example such as those described in U.S. Pat. Nos. 5,895,417; 5,941,845; and 6,129,724, used on the epicardial surface of the heart may be difficult in assuring a transmural lesion or complete blockage of electrical signals. In addition, current devices may have difficulty dealing with varying thickness of tissue through which a transmural lesion is desired.
Conventional accompanying imaging devices, such as fluoroscopy, are unable to detect perpendicular electrode orientation, catheter movement during the cardiac cycle, and image catheter position throughout lesion formation. The absence of real-time visualization also poses the risk of incorrect placement and ablation of structures such as sinus node tissue which can lead to fatal consequences.
Moreover, because of the tortuous nature of intravascular access, devices or mechanisms at the distal end of a catheter positioned within the patient's body, e.g., within a chamber of the heart, are typically no longer aligned with the handle. Steering or manipulation of the distal end of the catheter via control or articulation mechanisms on the handle is easily disorienting to the user as manipulation of a control on the handle in a first direction may articulate the catheter distal end in an unexpected direction depending upon the resulting catheter configuration leaving the user to adjust accordingly. However, this results in reduced efficiency and longer procedure times as well as increased risks to the patient. Accordingly, there is a need for improved catheter control systems which facilitate the manipulation and articulation of a catheter.
SUMMARY OF THE INVENTION
Accordingly, various methods and techniques may be effected to stabilize the images of the tissue when directly visualizing moving regions of tissue, such as the tissue which moves in a beating heart with an imaging assembly positioned in proximity to or against the tissue. Systems and mechanisms are described that can capture and process video images in order to provide a “stabilized” output image and/or create a larger composite image generated from a series of images for the purposes of simplifying the output image for user interpretation during diagnostic and therapeutic procedures.
Typically, images can be captured/recorded by a video camera at a rate of, e.g., 10-100 fps (frames per second), based on the system hardware and software configurations. Much higher video capture rates are also possible in additional variations. The images can then be captured and processed with customizable and/or configurable DSP (digital signal processing) hardware and software at much higher computational speeds (e.g., 1.5-3 kHz as well as relatively slower or faster rates) in order to provide real-time or near real-time analysis of the image data. Additionally, analog signal processing hardware may also be incorporated. A variety of algorithms, e.g., optical flow, image pattern matching, etc. can be used to identify, track and monitor the movement of whole images or features, elements, patterns, and/or structures within the image(s) in order to generate velocity and/or displacement fields that can be utilized by further algorithmic processing to render a more stabilized image. For the imaging assembly, examples of various algorithms which may be utilized may include, e.g., optical flow estimation to compute an approximation to the motion field from time-varying image intensity. Additionally, methods for evaluating motion estimation may also include, e.g., correlation, block matching, feature tracking, energy-based algorithms, as well as, gradient-based approaches, among others.
In some cases, the image frames may be shifted by simple translation and/or rotation and may not contain a significant degree of distortion or other artifacts to greatly simplify the image processing methods and increase overall speed. Alternatively, the hardware and software system can also create a composite image that is comprised (or a combination) of multiple frames during a motion cycle by employing a variety of image stitching algorithms. A graphical feature, e.g., a circle, square, dotted-lines, etc, can be superimposed or overlaid on the composite image in order to indicate the actual position of the camera (image) based on the information obtained from the image tracking software as the camera/hood undergoes a certain excursion, displacement, etc., relative to the target tissue of the organ structure.
An estimate of motion and pixel shifts may also be utilized. For example, a fibrillating heart can achieve 300 bpm (beats per minute), which equals 5 beats per second. Given a video capture rate of 30 fps (frames per second) there would then be roughly 6 frames captured during each beat. Given a typical displacement of, e.g., 1 cm of the camera/hood relative to the plane of the surface of the target tissue per beat, each image may record a displacement of about 1.6 mm per frame. With a field of view (FOV), e.g., of about 7 mm, then each frame may represent an image shift of about 23%. Given an image sensor size of, e.g., 220 pixels×224 pixels, the number of pixels displaced per frame is, e.g., 50 pixels.
Image processing and analysis algorithms may be extremely sensitive to instabilities in, e.g., image intensity, lighting conditions and to variability/instability in the lighting (or image intensity) over the sequence of image frames, as this can interfere with the analysis and/or interpretation of movement within the image. Therefore, mechanisms and methods of carefully controlling the consistency of the lighting conditions may be utilized for ensuring accurate and robust image analysis. Furthermore, mechanisms and methods for highlighting surface features, structures, textures, and/or roughness may also be utilized. For example, a plurality of peripheral light sources, e.g., from flexible light fiber(s), can create even symmetrical illumination or can be tailored to have one or all illuminating sources active or by activating sources near each other in order to provide focused lighting from one edge or possibly alternate the light sources in order to best represent, depict, characterize, highlight features of the tissue, etc. The light source can be configured such that all light sources are from one origin of a given wavelength or the wavelength can be adjusted for each light element. Also, the light bundles can be used to multiplex the light to other different sources so that a given wavelength can be provided at one or more light sources and can be controlled to provide the best feature detection (illumination) and also to provide the most suitable image for feature detection or pattern matching.
As further described herein, light fibers can be located at the periphery of the hood or they can be configured within the hood member. The incidence angle can be tailored such that the reflected light is controlled to minimize glare and other lighting artifacts that could falsely appear as surface features of interest and therefore possibly interfere with the image tracking system. The lighting requirements that provide optimal visual views of the target tissue for the user may vary from the lighting requirements utilized by the software to effectively track features on the target tissue in an automated manner. The lighting conditions can be changed accordingly for different conditions (e.g., direct viewing by the user or under software control) and can be automatically (e.g., software controlled) or manually configurable. Lighting sources could include, e.g., light emitting diodes, lasers, incandescent lights, etc., with a broad spectrum from near-infrared (>760 nm) through the visible light spectrum.
As the camera actively tracks its position relative to the target tissue, the power delivered by the RF generator during ablation may also be controlled as a function of the position of the hood in order to deliver energy to the tissue at a consistent level. In situations where the excursions of the hood/camera occur with varying velocity, the power level may be increased during periods of rapid movements and/or decreased during periods of slower movements such that the average delivery of energy per region/area (per unit time) is roughly constant to minimize regions of incomplete or excessive ablation thus potentially reducing or eliminating damage to surrounding tissue, structures or organs. Alternatively, the tracking of the target tissue may be utilized such that only particular regions in the moving field receive energy whereas other areas in the field receive none (or relatively less energy) by modulating the output power accordingly by effectively gating the power delivery to a location(s) on the target tissue. This technique could ultimately provide higher specificity and focal delivery of ablative energy despite a moving RF electrode system relative to the target tissue.
Active or dynamic control of the hood using control wires, etc., may also be used in order to match/synchronize the excursion of the device with that of the tissue by utilizing surface sensors and/or optical video image to provide feedback to motion control.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows a side view of one variation of a tissue imaging apparatus during deployment from a sheath or delivery catheter.
FIG. 1B shows the deployed tissue imaging apparatus of FIG. 1A having an optionally expandable hood or sheath attached to an imaging and/or diagnostic catheter.
FIG. 1C shows an end view of a deployed imaging apparatus.
FIGS. 2A and 2B show one example of a deployed tissue imager positioned against or adjacent to the tissue to be imaged and a flow of fluid, such as saline, displacing blood from within the expandable hood.
FIGS. 3A and 3B show examples of various visualization imagers which may be utilized within or along the imaging hood.
FIGS. 4A and 4B show perspective and end views, respectively, of an imaging hood having at least one layer of a transparent elastomeric membrane over the distal opening of the hood.
FIGS. 5A and 5B show perspective and end views, respectively, of an imaging hood which includes a membrane with an aperture defined therethrough and a plurality of additional openings defined over the membrane surrounding the aperture.
FIGS. 6A and 6B show perspective views of a targeted tissue region which is actively moving and a visualization assembly which is positioned against the tissue while also moving in a corresponding manner to effect a stable image of the moving tissue.
FIG. 7 illustrates a schematic diagram that represents an example of how the imaging output captured from the imager may be transmitted to a processor for processing the captured images as well as other data.
FIG. 8 shows a representative view of a visualization assembly electronically coupled to a video processing unit and an optional image processing unit for providing multiple images of the tissue region.
FIG. 9 depicts a series of images which may be captured during a total excursion of the tissue displacement of the hood relative to the moving tissue.
FIG. 10A shows an example of how an entire video image taken by the imager may be processed to identify one or more sub-sample regions at discrete locations.
FIGS. 10B and 10C show examples of how the identified sub-sample regions may be located in various patterns.
FIG. 11 illustrates how multiple captured images of the underlying tissue region may overlap when taken while the tissue moves relative to the hood over a predetermined time sequence.
FIG. 12 illustrates multiple images captured over an excursion length relative to the tissue region and processed to create a composite image.
FIG. 13 illustrates how a graphical feature such as a positional indicator can be superimposed over the composite image.
FIG. 14 illustrate an example of how the tissue image may be displayed in alternative ways such as the unprocessed image on a first monitor and the stabilized composite image on a second optional monitor.
FIGS. 15A and 15B show examples of alternative views of the tissue images which may be toggled via a switch on a single monitor.
FIGS. 16A and 16B show examples of end views of the hood having multiple sensors positioned upon the membrane.
FIGS. 17A and 17B show partial cross-sectional side views of examples of an optical tracking sensor which may be positioned upon the hood.
FIGS. 18A and 18B show partial cross-sectional side views of another example of an optical tracking sensor having integrated light sources for tracking the tissue images.
FIGS. 19A and 19B illustrate representations of a local coordinate system provided by the sensor and a global coordinate system relative to the tissue region of interest.
FIG. 20 shows an end view of an example of sensors which may be positioned along the hood over or upon the membrane for providing an estimated average of tissue displacement.
FIG. 21 shows another variation where an accelerometer may be mounted to the hood or along the catheter.
FIGS. 22A to 22D show various examples of various configurations for angling light incident upon the tissue surface.
FIGS. 23A and 23B show perspective assembly and end views, respectively, of a hood having multiple optical fibers positioned longitudinally along the hood to provide for angled lighting of the underlying tissue surface from multiple points of emitted light.
FIGS. 24A and 24B side and cross-sectional side views of the hood with a plurality of light fibers illuminating the surface of the target tissue.
FIGS. 25A and 25B show examples of light fibers having its ends further retracted for providing another lighting angle.
FIG. 26 shows illustrates yet another variation where a dark-field optical pathway may be created which highlights surface features of tissue but keeps the background relatively dark.
DETAILED DESCRIPTION OF THE INVENTION
A tissue-imaging and manipulation apparatus described herein is able to provide real-time images in vivo of tissue regions within a body lumen such as a heart, which is filled with blood flowing dynamically therethrough and is also able to provide intravascular tools and instruments for performing various procedures upon the imaged tissue regions. Such an apparatus may be utilized for many procedures, e.g., facilitating transseptal access to the left atrium, cannulating the coronary sinus, diagnosis of valve regurgitation/stenosis, valvuloplasty, atrial appendage closure, arrhythmogenic focus ablation, among other procedures. Although intravascular applications are described, other extravascular approaches or applications may be utilized with the devices and methods herein.
One variation of a tissue access and imaging apparatus is shown in the detail perspective views of FIGS. 1A to 1C . As shown in FIG. 1A , tissue imaging and manipulation assembly 10 may be delivered intravascularly through the patient's body in a low-profile configuration via a delivery catheter or sheath 14 . In the case of treating tissue, it is generally desirable to enter or access the left atrium while minimizing trauma to the patient. To non-operatively effect such access, one conventional approach involves puncturing the intra-atrial septum from the right atrial chamber to the left atrial chamber in a procedure commonly called a transseptal procedure or septostomy. For procedures such as percutaneous valve repair and replacement, transseptal access to the left atrial chamber of the heart may allow for larger devices to be introduced into the venous system than can generally be introduced percutaneously into the arterial system.
When the imaging and manipulation assembly 10 is ready to be utilized for imaging tissue, imaging hood 12 may be advanced relative to catheter 14 and deployed from a distal opening of catheter 14 , as shown by the arrow. Upon deployment, imaging hood 12 may be unconstrained to expand or open into a deployed imaging configuration, as shown in FIG. 1B . Imaging hood 12 may be fabricated from a variety of pliable or conformable biocompatible material including but not limited to, e.g., polymeric, plastic, or woven materials. One example of a woven material is Kevlar® (E. I. du Pont de Nemours, Wilmington, Del.), which is an aramid and which can be made into thin, e.g., less than 0.001 in., materials which maintain enough integrity for such applications described herein. Moreover, the imaging hood 12 may be fabricated from a translucent or opaque material and in a variety of different colors to optimize or attenuate any reflected lighting from surrounding fluids or structures, i.e., anatomical or mechanical structures or instruments. In either case, imaging hood 12 may be fabricated into a uniform structure or a scaffold-supported structure, in which case a scaffold made of a shape memory alloy, such as Nitinol, or a spring steel, or plastic, etc., may be fabricated and covered with the polymeric, plastic, or woven material. Hence, imaging hood 12 may comprise any of a wide variety of barriers or membrane structures, as may generally be used to localize displacement of blood or the like from a selected volume of a body lumen or heart chamber. In exemplary embodiments, a volume within an inner surface 13 of imaging hood 12 will be significantly less than a volume of the hood 12 between inner surface 13 and outer surface 11 .
Imaging hood 12 may be attached at interface 24 to a deployment catheter 16 which may be translated independently of deployment catheter or sheath 14 . Attachment of interface 24 may be accomplished through any number of conventional methods. Deployment catheter 16 may define a fluid delivery lumen 18 as well as an imaging lumen 20 within which an optical imaging fiber or assembly may be disposed for imaging tissue. When deployed, imaging hood 12 may expand into any number of shapes, e.g., cylindrical, conical as shown, semi-spherical, etc., provided that an open area or field 26 is defined by imaging hood 12 . The open area 26 is the area within which the tissue region of interest may be imaged. Imaging hood 12 may also define an atraumatic contact lip or edge 22 for placement or abutment against the tissue region of interest. Moreover, the diameter of imaging hood 12 at its maximum fully deployed diameter, e.g., at contact lip or edge 22 , is typically greater relative to a diameter of the deployment catheter 16 (although a diameter of contact lip or edge 22 may be made to have a smaller or equal diameter of deployment catheter 16 ). For instance, the contact edge diameter may range anywhere from 1 to 5 times (or even greater, as practicable) a diameter of deployment catheter 16 . FIG. 1C shows an end view of the imaging hood 12 in its deployed configuration. Also shown are the contact lip or edge 22 and fluid delivery lumen 18 and imaging lumen 20 .
As seen in the example of FIGS. 2A and 2B , deployment catheter 16 may be manipulated to position deployed imaging hood 12 against or near the underlying tissue region of interest to be imaged, in this example a portion of annulus A of mitral valve MV within the left atrial chamber. As the surrounding blood 30 flows around imaging hood 12 and within open area 26 defined within imaging hood 12 , as seen in FIG. 2A , the underlying annulus A is obstructed by the opaque blood 30 and is difficult to view through the imaging lumen 20 . The translucent fluid 28 , such as saline, may then be pumped through fluid delivery lumen 18 , intermittently or continuously, until the blood 30 is at least partially, and preferably completely, displaced from within open area 26 by fluid 28 , as shown in FIG. 2B .
Although contact edge 22 need not directly contact the underlying tissue, it is at least preferably brought into close proximity to the tissue such that the flow of clear fluid 28 from open area 26 may be maintained to inhibit significant backflow of blood 30 back into open area 26 . Contact edge 22 may also be made of a soft elastomeric material such as certain soft grades of silicone or polyurethane, as typically known, to help contact edge 22 conform to an uneven or rough underlying anatomical tissue surface. Once the blood 30 has been displaced from imaging hood 12 , an image may then be viewed of the underlying tissue through the clear fluid 30 . This image may then be recorded or available for real-time viewing for performing a therapeutic procedure. The positive flow of fluid 28 may be maintained continuously to provide for clear viewing of the underlying tissue. Alternatively, the fluid 28 may be pumped temporarily or sporadically only until a clear view of the tissue is available to be imaged and recorded, at which point the fluid flow 28 may cease and blood 30 may be allowed to seep or flow back into imaging hood 12 . This process may be repeated a number of times at the same tissue region or at multiple tissue regions.
FIG. 3A shows a partial cross-sectional view of an example where one or more optical fiber bundles 32 may be positioned within the catheter and within imaging hood 12 to provide direct in-line imaging of the open area within hood 12 . FIG. 3B shows another example where an imaging element 34 (e.g., CCD or CMOS electronic imager) may be placed along an interior surface of imaging hood 12 to provide imaging of the open area such that the imaging element 34 is off-axis relative to a longitudinal axis of the hood 12 , as described in further detail below. The off-axis position of element 34 may provide for direct visualization and uninhibited access by instruments from the catheter to the underlying tissue during treatment.
In utilizing the imaging hood 12 in any one of the procedures described herein, the hood 12 may have an open field which is uncovered and clear to provide direct tissue contact between the hood interior and the underlying tissue to effect any number of treatments upon the tissue, as described above. Yet in additional variations, imaging hood 12 may utilize other configurations. An additional variation of the imaging hood 12 is shown in the perspective and end views, respectively, of FIGS. 4A and 4B , where imaging hood 12 includes at least one layer of a transparent elastomeric membrane 40 over the distal opening of hood 12 . An aperture 42 having a diameter which is less than a diameter of the outer lip of imaging hood 12 may be defined over the center of membrane 40 where a longitudinal axis of the hood intersects the membrane such that the interior of hood 12 remains open and in fluid communication with the environment external to hood 12 . Furthermore, aperture 42 may be sized, e.g., between 1 to 2 mm or more in diameter and membrane 40 can be made from any number of transparent elastomers such as silicone, polyurethane, latex, etc. such that contacted tissue may also be visualized through membrane 40 as well as through aperture 42 .
Aperture 42 may function generally as a restricting passageway to reduce the rate of fluid out-flow from the hood 12 when the interior of the hood 12 is infused with the clear fluid through which underlying tissue regions may be visualized. Aside from restricting out-flow of clear fluid from within hood 12 , aperture 42 may also restrict external surrounding fluids from entering hood 12 too rapidly. The reduction in the rate of fluid out-flow from the hood and blood in-flow into the hood may improve visualization conditions as hood 12 may be more readily filled with transparent fluid rather than being filled by opaque blood which may obstruct direct visualization by the visualization instruments.
Moreover, aperture 42 may be aligned with catheter 16 such that any instruments (e.g., piercing instruments, guidewires, tissue engagers, etc.) that are advanced into the hood interior may directly access the underlying tissue uninhibited or unrestricted for treatment through aperture 42 . In other variations wherein aperture 42 may not be aligned with catheter 16 , instruments passed through catheter 16 may still access the underlying tissue by simply piercing through membrane 40 .
In an additional variation, FIGS. 5A and 5B show perspective and end views, respectively, of imaging hood 12 which includes membrane 40 with aperture 42 defined therethrough, as described above. This variation includes a plurality of additional openings 44 defined over membrane 40 surrounding aperture 42 . Additional openings 44 may be uniformly sized, e.g., each less than 1 mm in diameter, to allow for the out-flow of the translucent fluid therethrough when in contact against the tissue surface. Moreover, although openings 44 are illustrated as uniform in size, the openings may be varied in size and their placement may also be non-uniform or random over membrane 40 rather than uniformly positioned about aperture 42 in FIG. 5B . Furthermore, there are eight openings 44 shown in the figures although fewer than eight or more than eight openings 44 may also be utilized over membrane 40 .
Additional details of tissue imaging and manipulation systems and methods which may be utilized with apparatus and methods described herein are further described, for example, in U.S. patent application Ser. No. 11/259,498 filed Oct. 25, 2005 (U.S. Pat. No. 7,860,555); Ser. No. 11/763,399 filed Jun. 14, 2007 (U.S. Pub. 2007/0293724); and Ser. No. 12/118,439 filed May 9, 2008 (U.S. Pub. 2009/0030412), each of which is incorporated herein by reference in its entirety.
In utilizing the devices and methods above, various procedures may be accomplished. One example of such a procedure is crossing a tissue region such as in a transseptal procedure where a septal wall is pierced and traversed, e.g., crossing from a right atrial chamber to a left atrial chamber in a heart of a subject. Generally, in piercing and traversing a septal wall, the visualization and treatment devices described herein may be utilized for visualizing the tissue region to be pierced as well as monitoring the piercing and access through the tissue. Details of transseptal visualization catheters and methods for transseptal access which may be utilized with the apparatus and methods described herein are described in U.S. patent application Ser. No. 11/763,399 filed Jun. 14, 2007 (U.S. Pat. Pub. 2007/0293724 A1), incorporated herein by reference above. Additionally, details of tissue visualization and manipulation catheter which may be utilized with apparatus and methods described herein are described in U.S. patent application Ser. No. 11/259,498 filed Oct. 25, 2005 (U.S. Pat. Pub. 2006/0184048 A1), also incorporated herein above.
When visualizing moving regions of tissue, such as the tissue which moves in a beating heart, the relative movement between the imaging assembly in the device and the tissue region may result in tissue images which are difficult to capture accurately. Accordingly, various methods and techniques may be effected to stabilize the images of the tissue, e.g., (1) mechanical stabilization of the hood-camera assembly under dynamic control using imaging from the camera or surface sensors or both; (2) software stabilization (algorithmic based stabilization via pattern matching, feature detection, optical flow, etc); (3) sensor-based tracking of excursion of the assembly relative to the tissue (surface optical sensor, accelerometer, EnSite NavX® (St. Jude Medical, Minn.), Carto® Navigation System (Biosense Webster, Calif.), etc.) as feedback into an algorithm; and/or (4) signal feedback of biological functions into an algorithm (EKG, respiration, etc).
Systems and mechanisms are described that can capture and process video images in order to provide a “stabilized” output image and/or create a larger composite image generated from a series of images for the purposes of simplifying the output image for user interpretation during diagnostic and therapeutic procedures.
Typically, images can be captured/recorded by a video camera at a rate of, e.g., 10-100 fps (frames per second), based on the system hardware and software configurations. Much higher video capture rates are also possible in additional variations. The images can then be captured and processed with customizable and/or configurable DSP (digital signal processing) hardware and software at much higher computational speeds (e.g., 1.5-3 kHz as well as relatively slower or faster rates) in order to provide real-time or near real-time analysis of the image data. Additionally, analog signal processing hardware may also be incorporated.
A variety of algorithms, e.g., optical flow, image pattern matching, etc. can be used to identify, track and monitor the movement of whole images or features, elements, patterns, and/or structures within the image(s) in order to generate velocity and/or displacement fields that can be utilized by further algorithmic processing to render a more stabilized image. For example, see B. Horn and B. Schunck. Determining optical flow. Artificial Intelligence, 16(1-3):185-203, August 1981. and B. Lucas and T. Kanade. An iterative image registration technique with an application to stereo vision. In IJCAI 81, pages 674-679, 1981. and J. Shin, S. Kim, S. Kang, S.-W. Lee, J. Paik, B. Abidi, and M. Abidi. Optical flow-based real-time object tracking using non-prior training active feature model. Real - Time Imaging, 11(3):204-218, June 2005 and J. Barron, D. Fleet, S. Beauchemin. Performance of Optical Flow Techniques. International Journal of Computer Vision, 12 (1):43-77, 1994, D. Fleet, Y. Weiss. Optical Flow Estimation. Handbook of Mathematical Models in Computer Vision . (Editors: N. Paragios, et al.). Pages. 239-258, 2005.). Each of these references is incorporated herein by reference in its entirety. For the imaging assembly, examples of various algorithms which may be utilized may include, e.g., optical flow estimation to compute an approximation to the motion field from time-varying image intensity. Additionally, methods for evaluating motion estimation may also include, e.g., correlation, block matching, feature tracking, energy-based algorithms, as well as, gradient-based approaches, among others.
In some cases, the image frames may be shifted by simple translation and/or rotation and may not contain a significant degree of distortion or other artifacts to greatly simplify the image processing methods and increase overall speed. Alternatively, the hardware and software system can also create a composite image that is comprised (or a combination) of multiple frames during a motion cycle by employing a variety of image stitching algorithms, also known in the art (see e.g., R. Szeliski. Image Alignment and Stitching. A Tutorial. Handbook of Mathematical Models in Computer Vision . (Editors: N. Paragios, et al.). Pages 273-292, 2005), which is incorporated herein by reference in its entirety. A graphical feature, e.g., a circle, square, dotted-lines, etc, can be superimposed or overlaid on the composite image in order to indicate the actual position of the camera (image) based on the information obtained from the image tracking software as the camera/hood undergoes a certain excursion, displacement, etc., relative to the target tissue of the organ structure.
An estimate of motion and pixel shifts may also be utilized. For example, a fibrillating heart can achieve 300 bpm (beats per minute), which equals 5 beats per second. Given a video capture rate of 30 fps (frames per second) there would then be roughly 6 frames captured during each beat. Given a typical displacement of, e.g., 1 cm of the camera/hood relative to the plane of the surface of the target tissue per beat, each image may record a displacement of about 1.6 mm per frame. With a field of view (FOV), e.g., of about 7 mm, then each frame may represent an image shift of about 23%. Given an image sensor size of, e.g., 220 pixels×224 pixels, the number of pixels displaced per frame is, e.g., 50 pixels.
Image processing and analysis algorithms may be extremely sensitive to instabilities in, e.g., image intensity, lighting conditions and to variability/instability in the lighting (or image intensity) over the sequence of image frames, as this can interfere with the analysis and/or interpretation of movement within the image. Therefore, mechanisms and methods of carefully controlling the consistency of the lighting conditions may be utilized for ensuring accurate and robust image analysis. Furthermore, mechanisms and methods for highlighting surface features, structures, textures, and/or roughness may also be utilized. For example, a plurality of peripheral light sources, e.g., from flexible light fiber(s), or individual light emitting diodes (LEDs) can create even symmetrical illumination or can be tailored to have one or all illuminating sources active or by activating sources near each other in order to provide focused lighting from one edge or possibly alternate the light sources in order to best represent, depict, characterize, highlight features of the tissue, etc. The light source can be configured such that all light sources are from one origin and of a given wavelength or the wavelength can be adjusted for each light element. Also, the light bundles can be used to multiplex the light to other different sources so that a given wavelength can be provided at one or more light sources and can be controlled to provide the best feature detection (illumination) and also to provide the most suitable image for feature detection or pattern matching.
As further described herein, light fibers can be located at the periphery of the hood or they can be configured within the hood member. The incidence angle can be tailored such that the reflected light is controlled to minimize glare and other lighting artifacts that could falsely appear as surface features of interest and therefore possibly interfere with the image tracking system. The lighting requirements that provide optimal visual views of the target tissue for the user may vary from the lighting requirements utilized by the software to effectively track features on the target tissue in an automated manner. The lighting conditions can be changed accordingly for different conditions (e.g., direct viewing by the user or under software control) and can be automatically (e.g., software controlled) or manually configurable. Lighting sources could include, e.g., light emitting diodes, lasers, incandescent lights, etc., with a broad spectrum from near-infrared (>650 nm) through the visible light spectrum.
As the camera actively tracks its position relative to the target tissue, the power delivered by the RF generator during ablation may also be controlled as a function of the position of the hood in order to deliver energy to the tissue at a consistent level. In situations where the excursions of the hood/camera occur with varying velocity, the power level may be increased during periods of rapid movements and/or decreased during periods of slower movements such that the average delivery of energy per region/area (per unit time) is roughly constant to minimize regions of incomplete or excessive ablation thus potentially reducing or eliminating damage to surrounding tissue, structures or organs. Alternatively, the tracking of the target tissue may be utilized such that only particular regions in the moving field receive energy whereas other areas in the field receive none (or relatively less energy) by modulating the output power accordingly by effectively gating the power delivery to a location(s) on the target tissue. This technique could ultimately provide higher specificity and focal delivery of ablative energy despite a moving RF electrode system relative to the target tissue.
Active or dynamic control of the hood using control wires, etc., may also be used in order to match/synchronize the excursion of the device with that of the tissue by utilizing surface sensors and/or optical video image to provide feedback to motion control.
Turning now to FIG. 6A , a perspective view of a typical section of target tissue T from an organ that is actively moving, either due to contractility (such as in a heart), respiration, peristalsis, or other tissue motion, as depicted by arrows in the plane of the tissue, which can include lateral tissue movement 52 or rotational tissue movement 54 . The target tissue T can also experience displacement along an axis normal to the plane of the tissue. The hood 12 of the visualization assembly may be seen in proximity to the tissue region T where the hood 12 may be positioned upon an articulatable section 50 of the catheter 16 .
As shown in the perspective view of FIG. 6B , any movement of the underlying tissue region T may be matched by the catheter assembly by moving the hood 12 in a manner which corresponds to the movement of the tissue T. For instance, any axial displacement 58 of the hood 12 corresponding to any out-of-plane movement of the tissue region T may be achieved by advancing and retracting the catheter 16 . Similarly, any corresponding lateral catheter movement 56 of the hood 12 may be accomplished by articulating the steerable section 50 the catheter 16 to match correspondingly to the lateral movements 52 of the tissue T. Steerable section 50 may be manually articulated to match movements of the hood 12 with that of the tissue. Alternatively, computer control of the steerable section 50 may be utilized to move the hood 12 accordingly. Examples of steering and control mechanisms which may be utilized with the devices and methods disclosed herein may be seen in U.S. patent application Ser. No. 11/848,429 filed Aug. 31, 2007 (U.S. Pub. 2008/0097476) which shows and describes computer-controlled articulation and steering. Other examples include U.S. patent application Ser. No. 12/108,812 filed Apr. 24, 2008 (U.S. Pub. 2008/0275300) which shows and describes multiple independently articulatable sections; U.S. patent application Ser. No. 12/117,655 filed May 8, 2008 (U.S. Pub. 2008/0281293) which shows and describes alternative steering mechanisms; U.S. patent application Ser. No. 12/499,011 filed Jul. 7, 2009 (U.S. Pub. 2010/0004633); and Ser. No. 12/967,288 filed Dec. 14, 2010 which show and describe steering control mechanisms and handles. Each of these references are incorporated herein by reference in its entirety.
FIG. 7 illustrates a schematic diagram that represents an example of how the imaging output captured from the imager 60 (as described above) within or adjacent to the hood 12 may be transmitted to a processor 62 that may comprise imaging processing hardware as well as software algorithms for processing the captured images as well as other data. For instance, processor 62 may also receive signals from one or more sensors 64 located along or in proximity to the hood 12 which sense and detect positional information of the hood 12 and/or catheter 16 . Such sensors may include, e.g., surface optical tracking sensors, positional information received from a NavX® system, Carto® Navigation System (Biosense Webster, Calif.), accelerometers, etc. Processor 62 may also receive biological signals or physiological data 66 detected by one or more sensors also located along or in proximity to the hood 12 or from other internal or external inputs, e.g., electrocardiogram data, respiration, etc.
With the processor 62 programmed to receive and process both the positional information from one or more sensor signals 64 as well as physiological information of the subject from one or more biological signals 66 , the processor 62 may optionally display one or more types of images. For example, a composite image 70 may be processed and displayed where the image represents a composite image that is combined, stitched-together, or comprised of multiple images taken over the excursion distance captured by the imager 60 during relative movement between the tissue and hood 12 . Additionally and/or alternatively, a stabilized composite image 68 may be displayed which represents an image where the motion due to tissue displacement is reduced, minimized, or eliminated and a single view of an “average” image. Additionally and/or alternatively, a raw video image 72 may be displayed as well which shows the unprocessed image captured by the imager 60 . Each of these different types of images may be displayed individually or simultaneously on different screens or different portions of a screen if so desired.
FIG. 8 depicts the hood 12 and catheter 16 imaging a tissue region T which may undergo tissue displacement, e.g., within three degrees of freedom (linear displacements 52 and rotational displacement 54 ). The captured images may be transmitted to a video processing unit 80 (VPU) which may process the raw video images 72 for display upon a monitor. The VPU 80 may further transmit its images to an image processing unit 82 which may contain the processor 62 and algorithm for stabilizing and/or stitching together a composite image. The stabilized composite or averaged image 68 captured from tissue regions A, B, C during tissue movement can be viewed on a second monitor. Optionally, the processing function of image processing unit 82 can also be turned off or toggled, e.g., via a switch 84 , for use on one or more monitors to enable the physician to select the type of image for viewing. Additionally, although a typical target tissue T is described, the imaging angle of the tissue may change relative to the hood 12 during image capture of the tissue region T due to the relative tissue movement. Because of this changing image, images of the tissue T at various stages at a particular given time interval may be displayed if so desired for comparison.
As an example of the range of images the imager within or adjacent to the hood 12 may capture during relative tissue movement, FIG. 9 depicts a series of images which may be captured during the total excursion L of the tissue displacement of the hood 12 relative to the moving tissue. The image represented by the static field of view 90 through hood 12 shows an initial position of hood 12 relative to the tissue. As the tissue moves relative to the hood 12 , the sampling rate or frame rate of the imager may be sufficiently high enough such that as the tissue moves relative to the hood, each subsequent imaged tissue regions in a first direction 92 ′, 92 ″ may be captured at increments of a distance d which may allow for overlapping regions of the tissue to be captured. Likewise, the imaged tissue regions in a second direction 94 ′, 94 ″ may be captured as well at overlapping increments of distance d between each captured image.
In processing the captured images to provide a stabilized or composite tissue image for display, one example is illustrated in FIG. 10A which shows an example of how an entire video image 100 (e.g., 220×224) can be taken by the imager and then processed by the processor 62 to identify one or more sub-sample regions 102 (e.g., 10×10 pixel subsets up to 18×18 pixel subsets) at discrete locations. These identified sub-sample regions 102 may be identified consistently between each subsequent image taken for mapping and/or stitching purposes between the subsequent images. The sub-sample regions 102 may range between, e.g., 1-20 subsets, and may be oriented in various patterns to best match or be removed from obstructions (e.g., various hood features, etc.) for the most robust image quality and processing. FIG. 10B shows an example of how the identified sub-sample regions 102 ′ may be located in a first staggered pattern while FIG. 10C shows another example of how the sub-sampled regions 102 ″ can be identified along the corners of the image 100 . The location of the sub-sampled regions are illustrated for exemplary purposes and other locations over the image 100 may be identified as needed or desired.
With the sub-sample regions identified, FIG. 11 depicts how the multiple captured images 110 (e.g., F 1 , F 2 , F 3 , etc.) of the underlying tissue region may overlap when taken while the tissue moves relative to the hood 12 , e.g., at 1 cm increments, over a predetermined time sequence. Subsequent images may be automatically compared 112 by the processor 62 for comparison from one image to the other utilizing the identified sub-sample regions between each image. An example of such a comparison between two subsequent images is shown, e.g., between frame F 1 to frame F 2 and between frame F 2 and frame F 3 , etc. In this manner, multiple images may be compared between each sampled frame.
Another example is shown in FIG. 12 depicting multiple images (e.g., F 1 to Fn) which are captured over an excursion length L of the hood 12 relative to the tissue region. While the images are captured and tracked over a time period, the imaging processing unit 82 may receive these multiple images and process the images to create a composite image 120 stitched from each individual captured frame in order to simplify viewing by the user. With this composite image 120 , which can be continuously updated and maintained as the tissue T and/or hood 12 moves relative to one another, a graphical feature such as a positional indicator 122 , e.g. a circle, can be superimposed over the composite image 120 at a first location for display to the user to depict the actual position of the hood 12 in real time relative to the tissue T, as shown in FIG. 13 . Positional indicator 122 ′ is also illustrated at a second location along the tissue T. Use of the positional indicator for display may be incorporated to depict where the hood 12 is in real time relative to the tissue T, or more specifically, where hood 12 is relative to anatomical markers or features of interest, especially when using ablation energy.
As previously described and as shown in FIG. 14 , the tissue image may be displayed in alternative ways, such as the unprocessed image 72 on a first monitor 130 and the stabilized composite image 68 on a second optional monitor 132 . Alternatively, a single monitor 130 may be used with a switch 134 electrically coupled to the imaging processing unit 82 . Switch 134 may allow the user to compare one image with the other and decide which one is best suited for the task at hand, e.g., gaining access to the target region, exploring within the target region, or to stabilize and track the target tissue in order to commence with ablation or other therapy. Thus, the user may use the switch 134 to toggle between the unprocessed image view 72 , as shown in FIG. 15A , and the stabilized composite image 68 on a single monitor 130 , as shown in FIG. 15B .
In an alternative variation, rather than using the imager within or adjacent to the hood 12 for tracking and sampling the images of the underlying tissue, one or more individual sensors (as previously mentioned) may be positioned along or upon the hood 12 such as along the membrane 40 in proximity to aperture 42 . As shown in the end view of hood 12 in FIG. 16A , a first optical displacement sensor 140 is shown positioned upon membrane 40 with a second sensor 142 positioned on an opposite side of membrane 40 relative to first sensor 140 . Another variation is shown in the end view of FIG. 16B which shows membrane 40 with the addition of a third sensor 144 and fourth sensor 146 positioned along membrane 40 uniformly relative to one another around aperture 42 . In other variations, a single sensor may be used or any number of sensors greater than one may be utilized as practicable.
In use, multiple sensors may provide for multiple readings to increase the accuracy of the sensors and the displacements of the hood 12 may be directly tracked with the sensor-based modality like an optical displacement sensor such as those found in optical computer mice directly mounted to the face of the hood 12 (or some feature/portion of the hood 12 ). Additional sensors may be able to provide a more robust reading, especially if one sensor is reading incorrectly due to poor contact or interference from blood. Because the hood 12 is deformable, the relative position of each sensor relative to each other may be independent of one another, thus, the detected values may be averaged or any accumulated errors may be limited.
FIG. 17A shows a partial cross-sectional side view of one example of an optical tracking sensor 150 which may be positioned upon the hood 12 as described above. Sensor 150 may generally comprise a light source such as an optical fiber 152 optically coupled to a light source and having a distal end which may be angled with respect to the sensor 150 from which transmitted light 154 may be emitted such that the transmitted light 154 is incident upon the tissue T at an angle to create a side-lighting effect which may highlight or exaggerate surface features. FIG. 17B shows a partial cross-sectional side view of another variation where sensor 150 may also include a detector 156 having various sizes (e.g., 16×16 pixels, 18×18 pixels, or any other detector size) as well as a lens 158 . Moreover, although a single optical fiber 152 is shown, multiple fibers may be utilized in other variations.
FIG. 18A shows a cross-sectional side view of another variation of an optical displacement sensor 160 having an integrated light source 162 , e.g., light emitting diode (LED), laser, etc., rather than using a light source removed from the sensor 160 . The integrated light source 162 may be angled (or angled via a lens or reflector) such that the emitted light 164 incident upon the tissue T emerges at an angle relative to the tissue surface. An example of an integrated light source 162 (such as an LED) similar to a configuration of an optical mouse sensor is shown in the cross-sectional side view of FIG. 18B for integration into sensor 160 . As shown, the integrated light source 162 may be positioned within the sensor and a light pipe 166 may be positioned in proximity to the light source 162 to direct the emitted light through the sensor such that the emitted light 164 emerge at an angle with respect to the imaged tissue T to highlight/exaggerate surface features. The light reflected from the tissue may be reflected through lens 158 which may direct the reflected light onto detector 156 . The detected image may then be transmitted to the processor 62 , as previously described.
With respect to the use of one or more positional sensors, such sensors may be mounted upon or along the hood 12 and/or catheter 16 to calculate a position of the hood 12 . Additional examples of positional sensors which may be utilized with the systems and methods described herein are shown and described in further detail in U.S. patent application Ser. No. 11/848,532 filed Aug. 31, 2007 (U.S. Pub. 2009/0054803), which is incorporated herein by reference in its entirety. An example is shown FIG. 19A which illustrates a representation of a local coordinate system 170 for providing three degrees-of-freedom (e.g., x, y, θ) and a global coordinate system 172 referenced with respect to a predetermined grid, marker, pattern, etc. such as from tissue fiber images, tissue texture, etc. The sensor 140 positioned upon or along the hood 12 and/or catheter 16 may provide for proper sensing via local information generated relative to the sensor 140 itself (rather than global information) which may be calculated such that in the event the tracking is lost, the system can simply wait for a subsequent cardiac cycle (or tissue movement) to recalculate the excursion again as the tracking would only be active when the image is stabilized and the catheter control is well maintained. The local coordinate system 174 may for provide two degrees-of-freedom (e.g., x, y) referenced within the sensor 140 since the light source and sensing occurs from the same reference point.
Alternatively, the global coordinate system 172 may be utilized relative to the tissue region. If imaging of the tissue surface does not provide sufficient “markers” to track then alternative methods of providing fiducial markers may be utilized, e.g., sensor may calculate axial displacements (two degrees-of-freedom) and possibly at least one rotational degree-of-freedom to provide a rotational component. FIG. 19B shows another variation where only axial displacements are detected to provide a more robust sensing due to the relatively fewer pixel representations of the surface.
An example of sensors 140 , 142 which may be positioned along the hood 12 over or upon the membrane 40 in proximity to aperture 42 is shown in the end view of FIG. 20 . These positional sensors 140 , 142 may be independent or integrated with the sensors used for imaging. As shown, the one or more sensors may be used individually for detecting a linear translation of the hood 12 where the displacement of the entire hood 12 may be estimated based upon an averaging of the translation of each individual sensor where (y 1 +y 2 )/2=y hood and (x 1 +x 2 )/2=x hood . An angle of rotation may also be estimated by utilizing the rotation of each individual sensor where the overall rotation of the hood 12 is a function of the displacements of each sensor 140 , 142 . In this example, the overall estimated rotation of the hood, Θ hood =f ([x1, y1], [x2, y2]) and the overall displacement may be determined as an average between the displacements of each sensor 140 , 142 where y hood =(y 1 +y 2 )/2 and x hood =(x 1 +x 2 )/2. The use of the two sensors is illustrated as an example and more than two sensors may optionally be utilized. Moreover, the positioning of the sensors may be varied as well and are not limited to positioning upon the membrane 40 .
FIG. 21 shows another variation where an accelerometer 180 may be mounted to the hood 12 or along catheter 16 and may be used to provide a mechanism of gating or timing the excursions or at least the change in directions of detected movements 182 . This variation may be incorporated as another input to the tracking algorithm by the processor.
Turning back to the emission of an angled light incident upon the tissue surface, as previously mentioned the emitted light for surface detection may be angled relative to the sensor as well as relative to the tissue. An example is illustrated in the representative assembly of FIG. 22A , which shows an optical fiber 152 positioned at an angle such that the emitted light 154 is incident upon the tissue T at an angle, Θ. The angled light may illuminate surface features or details along the tissue surface that can be used for tracking. Low-angled (relative to the surface) side lighting provided by optical fiber 152 coupled to light source 194 may be used or an LED, laser, or other lighting elements could also be utilized along the hood 12 in proximity to the tissue surface to achieve similar low angled lighting to provide improved detail to small surface features. Alternately, the light source can be comprised of one or more LEDs mounted directly on or in the hood. The reflected light may be captured within the field of view 192 of imaging element 190 positioned within or adjacent to hood 12 , as shown.
FIG. 22B shows a variation where direct axial illumination, as shown, may be used where one or more optical fibers 152 , LEDs, or other light source may be positioned so as to emit light axially relative to the imaging element 190 . In this variation, the light is incident upon the tissue surface perpendicularly. FIG. 22C depicts another variation where a shallower angle of illumination can help highlight the features of the tissue surface in the captured images. FIG. 22D also illustrates another variation where multiple light sources 150 , 150 ′ may be used for emitting light 154 , 154 ′ at multiple angled positions for depicting tissue surface features at multiple angles.
FIG. 23A shows a perspective view of an assembly having a hood 12 with multiple optical fibers positioned longitudinally along the hood to provide for angled lighting of the underlying tissue surface from multiple points of emitted light. As illustrated also in the end view of hood 12 in FIG. 23B , the terminal emitting ends 202 of multiple optical fibers 200 (which may be each optically coupled to a common light source 194 or each individually to separate light sources) may be positioned circumferentially around the hood 12 such that the ends 202 are directed towards the aperture 42 . In this manner, the emitted light may converge on the aperture 42 (or any region of the tissue surface being visualized) to provide shallow angle edge lighting. The number of fibers can range anywhere from, e.g., 1 to 50 or more, and can be symmetrically or asymmetrically distribute about the hood face. Alternatively, optical fibers 200 may be replaced by individual LEDs.
FIG. 24A illustrates a side view of hood 12 with a plurality of light fibers 200 on the surface of the target tissue T and FIG. 24B shows a cross-sectional side view of FIG. 24A illustrating the illumination angle, Θ, of the incident light 204 which may penetrate the tissue T to a certain depth depending on the light intensity and wavelength.
Another variation is shown in the cross-sectional side view of FIG. 25A showing optical fibers 200 , LEDs, or other light sources along hood 12 with a relatively more retracted position of its ends 202 relative to the tissue surface to provide an alternative lighting scheme and to also enable to the light fibers to be shorter and not be subjected to the sharp bend and motion of the hood edge. As shown, the light fiber may have a relatively shallower tip angle, Θ, to redirect the light inward. FIG. 25B similarly depicts a hood 12 with light fibers 200 having its ends 202 which are further retracted for providing another lighting angle, Θ, as well as providing shorter light fibers that may be less prone to damage during hood manipulation or repeated deployments and retraction from within the delivery sheath.
FIG. 26 illustrates yet another variation where a dark-field optical pathway may be created which highlights surface features of tissue T but keeps the background relatively dark. Segmentation of the image may be effected to provide better detail in the raw image for further processing rather than trying to process an image (using thresholding, segmenting, etc.) with poorly defined detail and features. Typically, a higher quality image can be easier to process rather than applying powerful image processing algorithms to a poor quality image. In particular, the substrate may be relatively translucent or dark. In the case of tissue, it may be that the incident light spectrum can “penetrate” the tissue with little reflection and scatter, yet help highlight surface features or texture. This may be utilized with relatively thin or somewhat translucent tissue types or thin membranes.
The applications of the disclosed invention discussed above are not limited to certain treatments or regions of the body, but may include any number of other applications as well. Modification of the above-described methods and devices for carrying out the invention, and variations of aspects of the invention that are obvious to those of skill in the arts are intended to be within the scope of this disclosure. Moreover, various combinations of aspects between examples are also contemplated and are considered to be within the scope of this disclosure as well.
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Direct optical imaging of anatomical features and structures from within a biological organ in a dynamic environment (where the tissue being imaged is in motion due to cardiac rhythms, respiration, etc) presents certain image stability issues due (and/or related) to the motion of the target structure and may limit the ability of the user to visually interpret the image for the purposes of diagnostics and therapeutics. Systems and mechanisms for the purpose of actively stabilizing the image or for compiling and re-displaying the image information in a manner that is more suitable to interpretation by the user are disclosed.
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This application is a divisional of application Ser. No. 08/624,574 filed Apr. 4, 1996 now U.S. Pat. No. 5,728,843 which is a national stage entry of PCT/US 94/11246 filed Oct. 4, 1994 which is a continuation in part of U.S. application Ser. No. 08/131,484 filed Oct. 4, 1993 now abandoned.
BACKGROUND OF THE INVENTION
Field of the Invention
Tumor cells are more sensitive to radiation in the presence of oxygen than in its absence Powers et al., 1963). Even a small percentage of hypoxic cells within a tumor could limit response to radiation (Hall, 1988). Hypoxic radioresistance has been demonstrated in many experimental and animal tumors and hypoxia has been directly demonstrated in certain tumor types in man (Moulder et al., 1984; Peters et al., 1982). The occurrence of hypoxia in human tumors has in most cases been inferred from histologic findings and from evidence of hypoxia in animal tumor studies. In vivo demonstration of hypoxia has required tissue measurements with oxygen electrodes and the invasiveness of this technique has limited its application. Most attempts to increase the radiosensitivity of tumors by administration of chemical radiosensitizers have not been successful (Gatenby, et al., 1988; Kayama et al., 1991; Maor et al., 1981). However, there has been no clinically applicable means of demonstrating tumor hypoxia and it has not been possible to identify the patients who could potentially benefit from radiosensitizing therapy. Potential advantages of neutrons over more conventional radiation include a lesser dependence on oxygenation of the tumor and a lower variability of cell neutron sensitivity around the cell cycle.
3- 18 F!Fluoro-1-(2'-nitro-1'-imidazoyl)-2-propanol ( 18 F-fluoromisonidazole; FMISO) has been used with positron emission tomography (PET) to differentiate metabolically active hypoxic tumor from well-oxygenated metabolically active tumor. 18 F-FMISO is metabolized by intracellular nitroreductases and acts as a competing electron acceptor at low oxygen levels. The 18 FMISO is reduced and subsequently incorporated into metabolically active hypoxic cells by covalent bonding to various macromolecules. Recent studies have shown that PET, in view of its ability to monitor cell oxygen content through 18 F-FMISO, has a high potential to predict treatment response. (Koh et al., 1992; Valk et al., 1992; Martin et al., 1989; and Rasey et al., 1989.)
Assessment of tumor hypoxia with 18 F FMISO prior to radiation therapy provides a rational means of selecting patients for treatment with chemical radiosensitizing drugs. Such selection of patients permits more accurate evaluation of radiosensitizing drugs, since their use could be limited to patients with hypoxic tumors, who could potentially benefit. In addition, it is possible to differentiate radiotherapy modalities (neutron versus photon radiotherapy) by correlating 18 F!FMISO results with tumor response.
The synthesis of 18 F!FMISO reported by others showed no resemblance to the present inventive methods. Most studies used a two-part, two-step synthetic procedure, whereas the precursor of the present invention has a nitroimidazole moiety. Although there is a great demand in PET for 18 F!FMISO, a simple and efficient synthesis to produce sufficient radioactivity of 18 F!FMISO is difficult. Prior studies used 18 F!epifluorohydrin to react with 2-nitroimidazole (Hwang et al., 1989; Jerabek et al., 1986; Grierson et al., 1989). The reaction takes a longer time (90 min.) and provides a lower radiochemical yield. One aspect of the present invention concerns a more rapid synthesis of 18 F!FMISO.
Three classes of agents have found practical use for therapy against hypoxia tumors (Hall, 1994). These are (1) radiosensitizers of hypoxic cells, (2) chemopotentiation agents and (3) bioreductive drugs. Radiosensitizers are chemical or pharmacologic agents that increase the lethal effects of radiation when administered in conjunction with it. Nitroimidazoles were reported to potentiate the cytotoxic effects when combined with other chemotherapeutic agents (e.g. cisplatin, bleomycin, cyclophosphamide and nitrosourea). Several clinical trials are in progress combining a radiosensitizer with alkylating agents. It would increase the efficiency of chemotherapy if the hypoxia component could be identified by a labeled tracer prior to the therapy. Bioreductive drugs are not radiosensitizers, yet, these drugs are reduced intracellularly in hypoxia cells to form active cytotoxic agents. Three drugs are primarily used in clinical trials. These drugs are mitomycin C, triapazamine (SR4233) and dual-function nitroheterocyclic compounds (RB6145).
Two nitroimidazole analogues (misonidazole and etanidazole) are potent radiosensitizers. In clinical trails, patients with high hemoglobin levels and cancer of the pharynx showed a great benefit from the addition of these analogues (Hall, 1994). However, the dose-limiting toxicity was found to be peripheral neuropathy that progressed to central nervous system toxicity if drug administration was not stopped. This neurotoxicity prevented the use of the drug at adequate dose levels throughout multifraction treatments.
Therefore, it is necessary to develop a more hydrophilic agent than misonidazole. This would allow the agent to have shorter half-life in vivo and, be expected to show less neurotoxicity. Another aspect of the present invention is the synthesis and evaluation of a new 2-nitroimidazole analogue which is more hydrophilic than FMISO and misonidazole. The synthetic scheme is shown in FIG. 6.
SUMMARY OF THE INVENTION
The present invention includes a first description of new compounds including: 1-(2'-nitro-1'-imidazolyl)-2-O-acetyl-3-O-tosylpropanol; glycerol-1,3-ditosylate-2-O-acetylate; 1-(2'-nitro-1'-imidazolyl)-2,3-acetyl-4-O-tosylbutanol; and threitol 1,4-di-tosylate-2,3-O-di-acetylate.
The present invention also involves a method for preparing 1-(2'-Nitro-1'-imidazolyl)-2-O-acetyl-3-O-tosylpropanol comprising reacting glycerol-1,3-ditosylate-2-O-acetylate with 2-nitroimidazole. This reaction is preferably in dimethylformamide in combination with cesium carbonate. Preferable conditions for this reaction are at a temperature of 50° C. and for a time of about 1 hour. The present invention also involves a method for preparing 18 F-fluoromisonidazole comprising reacting 1-(2'-nitro-1'-imidazolyl)-2-propanol with 18 F complexed with 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo 8,8,8!hexacosane or the like. This reacting is preferably in an acetonitrile solvent. Reaction conditions here are preferably from about 90° C. to about 100° C.
Methods of the present invention include: A method for preparing 1-(2'-nitro-1'-imidazolyl)-2,3-acetyl-4-O-tosylbutanol comprising reacting threitol-1,4-di-tosylate-2,3-O-acetylate with 2-nitroimidazole. Also part of the present invention is a method for preparing a 18 F-fluoromisonidazole butanol analogue useful for PET imaging and localization of hypoxia tissue. This method comprises reacting 1-(2'-nitro-1'-imidazolyl)-2,3-acetyl-4-O-tosylbutanol with 18 F complexed with 4,7,13,16,21,24-hexaoxo-1,10-diazabicyclo(8,8,8)hexacosane or the like. The present invention also comprises a method for preparing 131 I-iodomisonidazole comprising reacting 1-(2'-nitro-1'-imidazolyl)-2-acetyl-3-O-tosylpropanol with a salt of 131 I such as Na 131 I.
Another aspect of the present invention is the preparation of a more hydrophilic analogue of misonidazole, 18 F!fluoroerythro-2-nitroimidazole. This compound is prepared from a novel precursor, (2'-nitro-1'-imidazolyl)-2,3-isopropylidene-4-tosylbutanol.
The method for preparing (2'-nitro-1'-imidazolyl)-2,3-isopropylidene-4-tosylbutanol comprises reacting 1,4-ditosyl-2,3-isopropylidene-D-threitol with 2-nitroimidazole, and preferably the reacting is in dimethylformamide, and preferably the reacting is in the presence of cesium carbonate. The reacting is also preferably at about 60° C. for about 1 hour.
A further aspect of the invention is a method for preparing 18 F!fluoroerythro-2-nitroimidazole comprising reacting (2'-nitro-1'-imidazolyl)-2,3-isopropylidene-4-tosylbutanol with 18 F complexed with 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo 8,8,8!hexacosane. In this method, the reacting is preferably in acetonitrile.
An embodiment of the present invention is a method of use of 18 F!fluoroerythro-2-nitroimidazole for assessing tumor hypoxia. The method of use preferably comprises administering to a patient an effective amount of 18 F!fluoroerythro-2-nitroimidazole and subjecting the patient to positron emission tomography or single photon emission computed tomography.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically shows the synthesis of 18 F!fluoromisonidazole and its analogue.
FIG. 2 schematically shows the synthesis of -(2'-nitro-1'-imidazolyl)-2,3-O-acetyl-4-O-tosyl butanol.
FIG. 3 shows a PET image of a patient with nasalpharyngeal cancer (NPC) after receiving 10 mCi each of ( 18 F)FMISO prepared according to the present invention.
FIG. 4 shows a PET image of a second patient with nasalpharyngeal cancer (NPC) after receiving 10 mCi each of ( 18 F)FMISO prepared according to the present invention.
FIG. 5 schematically shows the radiosynthesis of ( 131 I)iodomisonidazole.
FIG. 6 schematically shows the synthesis of 18 F!FETNIM.
FIG. 7 shows the PET images of tumor bearing rabbits 1 hour post-injection with 18 F!FETNIM.
FIG. 8 shows the autoradiogram and photographic studies of mammary tumor bearing rats treated with 18 F!FETNIM, 18 F!FDG and 18 F!FMISO.
FIG. 9 is a histogram showing tumor-to-tissue ratios of 18 F!FETNIM in tumor bearing rats.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present precursors for the preparation of 18 F!FMISO or its butanol analog are of value clinically and scientifically. The precursor for 18 F!FMISO is 1-(2'-nitro-1'-imidazolyl)-2-O-acetyl-3-O-tosylpropanol. Such a precursor can be radiolabeled in a short time with 18 F (t1/2=(109.7 min.), 123 I (t1/2=13.3 hours) or 131 I. The first two radioisotopic ligands are useful to detect hypoxic tumor volume by positron emission tomography (PET) and single photon emission computed tomography (SPECT).
18 F!FMISO was prepared as schematically shown in FIG. 1. Glycerol-1,3-ditosylate (compound 2) was obtained by treating glycerol with tosyl chloride according to a previously reported method (Benbouzid et al., 1988). Compound 3 (2-acetyl glycerol-1,3-ditosylate) was prepared by reacting glycerol-1,3-ditosylate with anhydrous acetic anhydride and BF 3 .etherate (yield 100%). In a mixture of compound 3, 2-nitroimidazole and Cs 2 CO 3 in dry DMF at 50° C., compound 4 1-(2'-nitro-1'-imidazolyl)-2-O-acetyl-3-O-tosylpropanol! was prepared. (When this reaction was carried out at 100° C. for 16 hr, the undesired compound 5 resulted.) HPLC showed the retention time of compound 4 to be 9.83 minutes (UV 310 nm, C-18 reverse phase column eluted with H 2 O:MeOH; 0-80% at a flow rate of 1.5 ml/min.
The butanol FMISO analog was analogously prepared.
Compound 1 ( 18 F!fluoromisonidazole) is prepared just prior to use by reacting compound 4 with 18 F!/KRYPTOFIX® 222.
Reagents and conditions for the steps in FIG. 1 and FIG. 2: i) TsCl (2eq), Pyridine, 0° C., 48 h (90%); ii) Ac 2 O (1.5 eq) BF 3 .Et 2 O (in anhydrous ether, 0° C., 30 min (100%), iii) 2-nitroimidazole, (0.9 eq), Cs 2 CO 3 (0.9 eq), DMF, 50° C., 1 h (48%); iv) 18 F!/KRYPTOFIX , CH 3 CN, 95° C., 10 min., H + , 90° C., 5 min. (12-18%).
Accomplished syntheses of misonidazole and misonidazole analogue precursors, 18 F-fluoromisonidazole (FMISO), 131 I!iodomisonidazole ( 131 I-IMISO) and 18 F-fluoromisonidazole analogues are described in the Examples below.
The synthesis scheme for 18 F!FETNIM is depicted in FIG. 6. Biodistribution studies of 18 F!FETNIM were performed at 1, 2 and 4 hours in mammary tumor-bearing rats (10 μCi, iv, N=3/time interval). Autoradiograms were performed at 1 hour postinjection of 18 F!FETNIM, and a comparison has been made with 18 F!fluoromisonidazole (FMISO). Intratumoral oxygen tension measurements were performed using the Eppendorf computerized histographic system. Twenty to twenty-five pO 2 measurements along each of 2 to 3 linear tracks were performed at 0.4 mm intervals on each tumor. PET imaging studies of 18 F!FETNIM were performed in rabbits bearing V2 tumors (N=3, 4 mCI, iv) which were located on the right leg.
Biodistribution of 18 F!FETNIM at 1, 2 and 4 hours showed tumor/blood count density ratios of 2.29±0.599, 2.41±0.567 and 8.02±2.420; tumor/muscle ratios of 0.66±0.267, 2.11±0.347 and 5.92±2.240, respectively. Bone uptake did not alter significantly. Autoradiograms indicated that 18 F!FETNIM and 18 F!FMISO could differentiate hypoxic versus necrotic regions in the tumor. The tumor oxygen tension, measured by an oxygen needle probe; was 3.2-6.0 mmHg. PET imaging studies indicated that the hypoxic tumor could be visualized at 1 hour postinjection.
The data disclosed herein indicate that 18 F! FETNIM and 18 F!FMISO are selective to hypoxic cells. However, 18 F!FETNIM appears to be more hydrophilic than 18 F!FMISO as evidenced from the autoradiogram and chemistry. Therefore, 18 F!FETNIM has the potential to be used as a diagnostic tool and as a follow-up for conventional therapy or chemotherapy of hypoxic tumors. Other useful applications of this compound would be in the diagnosis of brain ischemia (acute stroke), nasopharyngeal cancer, inflammation and cardiac infarction. Additionally, because of the selectivity and specificity of 18 F!FETNIM, labeling erythronitroimidazole with a high dose of 131 I would allow for radionuclide therapy of hypoxic tumors.
In summary, a simple and efficient synthetic method to produce sufficient radioactivity of 18 F!fluoroerythronitroimidazole, a new PET agent for imaging tumor hypoxia, has been prepared. PET imaging studies, autoradiograms and biodistribution of this compound indicate that 18 F!fluoroerythronitroimidazole is selective to hypoxic cells, chemically stable and more hydrophilic than misonidazole. It is thus a useful compound for the evaluation of hypoxic tumors. The diagnostic information obtained from 18 F!FETNIM would be important for the follow-up therapy of patients with hypoxic tumors.
EXAMPLE 1
Experimental Section (Applying to these Examples)
Nuclear magnetic resonance (NMR) spectra ( 1 H and 13 C) were recorded at ambient temperature on an IBM-Bruker Model NR/200 AF spectrometer in the Fourier transform mode in CDC13 with tetramethylsilane as an internal reference. Chemical shifts (d) are reported in parts per million (ppm) and coupling constants (J) in hertz. Mass spectral analyses were conducted at the University of Texas, Health Science Center at Houston, Texas. The mass data was obtained by fast-atom bombardment on a Kratos MS50 instrument. The elemental analyses were conducted at Galbraith Laboratories Inc. (Knoxville, Tenn.). High resolution mass spectroscopy (HRMS) was performed at the Midwest Center for Mass Spectrometry (Lincoln, Nebr.). All chemical reactions were conducted in dry glassware and were protected from atmospheric moisture. Solvents were dried over freshly activated (300° C., 1 h) molecular sieves (type 4A). The homogeneity of the products was determined by ascending thin-layer chromatography (TLC) on silica-coated glass plates (silica gel 60 F 254, Merck) with mixtures of CHCl 3 -MeOH as the eluting solvent. Preparative separations were performed by column chromatography on silica gel (Merck, 230-400 mesh) with mixtures of CHCl 3 -MeOH as eluant.
EXAMPLE 2
Synthesis of qlycerol-1,3-ditosylate (Compound 2)
Compound 2 was synthesized according to the previous reported method with modifications (Benbouzid et al., 1988). p-Toluenesulfonyl chloride (10.29 g, 54 mmol) dissolved in dry pyridine was added to a stirred solution of anhydrous glycerol (2.48 g, 27 mmol) in dry pyridine (30 ml at 0° C.). The solution was added slowly and left to react for 44 hours in the refrigerator (0°-3° C.). The pink mixture was poured over crushed ice and acidified with concentrated HCl. The organic layer was separated and the aqueous layer was washed with methylene chloride (2×50 ml). The combined organic extracts were washed successively with 2N HCl (2×10 ml) and distilled water (2×10 ml) and dried over anhydrous Na 2 SO 4 . The filtrate was evaporated and the residual crude product was purified by column chromatography on silica gel to afford Compound 2 as an oil: 9.72 g (24.3 mmol) yield 90%. 1 H NMR Chemical shift (d), multiplicity, coupling constant (Hz), number of protons, atom!: 7.75 (d; J=8.2 Hz; 4H, Har.); 7.35 (d; J=8.2 Hz; 4H; Har.); 4.1 (bs; 4H; H 1 ,3); 3.35 (bs; 1H; H 2 ); 2.4 (s; 6H; 2CH 3 ). 13 C NMR (ppm): 145 (C ar.); 131.7 (C ar.); 129.7 (CH ar.); 127.6 (CH ar.); 69.3 (C 1 ,3); 66.7 (C 2 ); 21.2 (CH 3 ) Satisfactory 1 H and 13 C NMR data as well as mass spectral data were recorded for this compound. These spectra were consistent with the structures shown in FIG. 1.
EXAMPLE 3
Synthesis of Glycerol-1,3-ditosylate-2-O-acetylate (compound 3)
Glycerol-1,3-ditosylate (5 g, 12.5 mmol) was added dropwise, while stirring 5 minutes at about 0° C., to a solution of acetic anhydride (2 ml, 20 mmol) and BF 3 .etherate (1.0 ml) in anhydrous ether (50 ml). The reaction mixture was stirred for 10 minutes, washed successively with 25%. sodium acetate solution (10 ml) and water (2×15 ml), and then dried over anhydrous sodium sulfate. The solvent was evaporated to yield glycerol-1,3-ditosylate-2-O-acetylate as a white solid (5.48 g, 12.4 mmol). The structure of the product was confirmed by 1 H-NMR 13 C-NMR, mass spectral data and elemental analysis. These spectra were consistent with the structure of glycerol-1,3-ditosylate-2-O-acetylate shown in FIG. 1. 1 H NMR: 7.8 (d; J=8.0 Hz; 4H; Har.); 7.3 (d; J=8.0 Hz; 4H; Har.); 5.05 (t; J-4.8 Hz; 1H; H 2 ); 4.1 (d; J=4.8 Hz; 4H; H 1 ,3); 2.4 (s; 6H; 2CH3ar.); 1.8 (s; 3H; CH 3 ac.). 13 C NMR (ppm): 169.6 (COCH 3 ); 145.3 (C ar.); 132.2 (C ar.); 130 (CH ar.); 127.9 (CHar.); 68.1 (C 2 ); 66.5 (C 1 ,3); 21.6 (CH 3 ar.); 20.5 (OCOCH 3 ). mass FAB, (C 19 H 22 S 2 O 8 ) + ! m/z: 441 (M + , 5%); 383 (M + --OCOCH 3 , 4%); 271 (M + -tosylate, 100%), 229 (M + +1-tosylate --COCH 3 ; 3%). Anal. Calc. (C 19 H 22 S 2 O 8 ) : C: 51.58, H:4.97 Found: C:51.50 H:4.93.
EXAMPLE 4
Synthesis of 1-(2'-Nitro-1'-imidazolyl)-2-O-acetyl-3-O-tosvlpropanol (Compound 4)
A mixture of glycerol-1,3-ditosylate-2-O-acetylate (0.44 g, 1 mmol), 2-nitroimidazole (0.1 g, 0.9 mmol) and cesium carbonate (0.29 g, 0.9 mmol) in 10 ml of dry DMF, through which argon was bubbled for 10 minutes. The mixture was heated at 50° C. for 1 hour. The mixture was then cooled and DMF was carefully removed under reduced pressure. The residue was taken up in ethyl acetate and filtered. Removal of ethyl acetate in vacuo gave a yellow oil which was chromatographed on silica gel eluted with 50-67% ethyl acetate/petroleum ether to afford 1-(2'-Nitro-1'-imidazolyl)-2-O-acetyl-3-O-tosylpropanol as a white solid (0.17 g, 0.43 mmol), yield 48%. This was dried in vacuo and stored at 0° C. The structure of compound 4 was confirmed by 1 H-NMR, 13 C-NMR, and mass spectral data. The spectra were consistent with the structure of 1-(2'-nitro-1'-imidazolyl)-2-O-acetyl-3-O-tosylpropanol shown in FIG. 1. HPLC showed the retention time of this compound to be 9.83 minutes (UV 310 nm, C-18 reverse phase column, eluted with water/methanol 0-80% at a flow rate of 1.5 ml/min). However, if the reaction was heated at 100° C. for 16 hours, a major byproduct (Compound 5) was isolated.
Compound 4: IR (Nujol) (cm -1 ): 1760; 1610; 1560; 1500; 1480; 1300; 1240; 1200. 1 H NMR: 7.8 (d; 2HJ=8.1 Hz; 2Har), 7.4 (d; 2H; J=8.1 Hz; 2Har), 7.1 (d; 2H; J-2.9; H-imidazolyl), 5.3 (m; 1H; H 2 ), 4.85 (dd; 1H; J=14.4, 3.5 Hz; H 3a ), 4.5 (dd; 1H; J=14.4, 8.4 Hz; H 3b ), 4.2 (dd; 2H; J=5,4.1 Hz; H 1 ), 2.45 (s; 3H; CH3tosyl), 1.95 (s; 3H; CH3ac). 13 C NMR (50 MHz), d(ppm): 169.3 (C═O), 145.6 (Car), 132 (Car), 130.1 (CHar), 129.9 (C-imidazolyl), 128.3 (CH-imidazolyl), 127.9 (CHar), 126.5 (CH-imidazolyl), 68.8 (C 2 ), 67.2 (C 1 ), 49.3 (C 3 ), 21.6 (CH 3 tosyl), 20.3 (CH 3 ac). HRMS calc. for C 15 H 18 N 3 SO 7 384.08655, Found 384.0869.
Compound 5: 1 HNMR: 7.15 (2H, H-imidazolyl); 4.9 (S, 1H, H-imidazolyl); 4.8 (m, 1H, H 2 ); 4.2 (d, 4H, J=3.5 Hz); H 1 ,3), 2.1 (S, 3H, CH 3 ). 13 CNMR; 171.1 (C═O), 127.7 (CH-imidazolyl); 68.2 (CH--NO 2 ); 65.4 (C 2 ) ; 52.8 (C 13 ), 21 (CH 3 ac). HRMS calcd for C 8 H 12 N 3 O 4 214.08278, found 214.0827.
EXAMPLE 5
Radiosynthesis of 18 F!FMISO (Compound 1)
18 F!Fluoride was obtained from the cyclotron facility of the University of Texas M.D. Anderson Cancer Center as produced by proton irradiation of enriched 18 O!water in a small-volume silver target. An aliquot containing 250-500 mCi of 18 F activity was combined with 26 mg of 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo 8,8,8!hexacosane (KRYPTOFIX® 222) and anhydrous potassium carbonate (4.6 mg), heated under reduced pressure to remove 18 O! water, and dried by azeotropic distillation with acetonitrile (3×1.5 ml). The tosyl analogue of misonidazole (compound 4) (5 mg), prepared from 1,3-ditosyl-2-O-acetyl glycerol (compound 3) was dissolved in acetonitrile (1.5 ml), and the KRYPTOFIX® 222-fluoride complex added. The mixture was then warmed at 95° C. for 10 min. After cooling, the reaction mixture was passed through a silica gel Sep-Pak column (Whatman Lab, Clifton, N.J.) and eluted with ether (2×2.5 ml): The solvent was evaporated and the resulting mixture hydrolyzed with 1N HCl (2 ml) at 90° C. for 5 min. The resultant mixture was cooled under N 2 and neutralized with 2N NaOH (0.8 ml) and 1N NaHCO 3 (1 ml). The mixture was then processed by passage through a short alumina C-18 (Sep-Pak) column and a 0.22 μm Millipore filter, followed by 5 ml of 10% ethanol saline. Comparison with an 1 H-NMR spectrum of the unlabeled fluoromisonidazole (FMISO) confirmed the structure. A yield of 20-40 mCi of pure product was isolated (12-18% yield, decay corrected) with end-of-bombardment (EOB) at 60-70 min. HPLC was performed on a C-18 Radial-Pak column, 8×100 mm, with pure water, using a flow rate of 1 ml/min. The no-carrier-added product corresponded to the retention time (4.8 min) of the unlabeled fluoromisonidazole under similar conditions. The radiochemical purity was greater than 95%. Under UV detection (310 nm), there are no other impurities. A radio-TLC scanner (Bioscan, Washington, DC) showed the retardation factor of 0.5 for the final product, using a silica gel plate G/UV 254, 5×20 cm (Whatman, Anaspec, Mich.) chloroform: methanol (7:3) eluant, which corresponded to unlabeled FMISO. In addition, KRYPTOFIX® 222 was not visualized (developed in iodine chamber) on the silica gel-coated plate using 0.1% v/v triethylamine in methanol as an eluant. The specific activity of FMISO was determined to be in the range of 1-2 Ci/μmol based upon UV and radioactivity detection of a sample of known mass and radioactivity. The identity and purity of 18 F!FMISO were confirmed by HPLC.
EXAMPLE 6
Half-life Test of 18 F!fluoromisonidazole
After the 18 F!fluoromisonidazole was prepared, an aliquot (10 μCi) of this radioactive product was counted on a gamma counter at various time intervals (30, 60, 120 min.). To assure the correct isotope ( 18 F) is incorporated into the nitroimidazole analogue, the radioactivity of the final product at different time intervals is counted and decay is corrected.
EXAMPLE 7
Sterility and Pyrogenicity
To demonstrate sterility, each batch of product is tested using Bactec culture vials with aerobic and anaerobic materials (NR6 and NR7) (Towson, Md.). An aliquot (0.3 ml) of the final solution is incubated in vials for 7 days at 37° C. Sterility is examined every day and assayed by visualizing the cloudiness of the solution. The ten samples tested have consistently been shown to be sterile.
To assure low or absent pyrogenicity, a LAL kit (Whittaker Bioproduct, Walkersville, Md.) is used. To prove drug solution does not enhance or inhibit the LAL test, we used three 1:1 dilutions (0.25 ml of drug solution to 0.25 ml of sterile water) to test pyrogenicity of each batch of product. Compared to standard solutions (12.5 Eμ/ml, 1.25 Eμ/ml and negative), the tested product solutions (ten samples) proved to be pyrogen-free (0 Eμ/ml) and did not interfere with the assay sensitivity.
EXAMPLE 8
Pharmacology and Toxicology Data
Pharmacology
Fluoromisonidazole (FMISO) has been shown to bind selectively to hypoxic cells in vitro and in vivo at radiobiologically significant oxygen levels. In patient studies, the hypoxic elements within a tumor volume was defined as regions with a threshold regional tumor to plasma ( 18 F-FMISO) ratio of ≧1.4 by 2 or more hours after injection.
The following Table summarizes the results of dosimetry calculation for radiation exposure to several hormonal tissues.
______________________________________Dosimetry: Normal Tissue Dosimetry for .sup.18 F-FMISOOrgan mrad/mCi ± SD 7 mCi/70 Kg______________________________________Liver 26.8 ± 9.7 190 mrad (n = 3)Kidney 25.8 ± 5.5 180 mrad (n = 3)Muscle 16.8 ± 7.9 120 mrad (n = 6)Bladder 81.5 ± 47 570 mrad (n = 2)______________________________________
Muscle is typical of most normal tissues; the total body musculature receives 120 mrem in a routine study for a 70 Kg male given the dose of 0.1 mCi/Kg. The liver and kidneys receive nearly twice the muscle dose, and the bladder wall about five times as much.
The data obtained from this study demonstrate the feasibility of using 18 F-FMISO to detect hypoxia in human head and neck tumors. Clinical trials will determine whether a relationship exists between 18 F-FMISO uptake and tumor radiation response.
Toxicity
Nitroimidazoles are chemotherapeutically important as antiprotozoal and antibacterial agents (Hoffer et al.). The most common side effect of MISO toxicity is peripheral sensory neuropathy of the hands and feet, characterized by mild to moderate paresthesias and loss of vibration sensitivity (McNeill et al.) . Others have reported convulsions after large single doses, and the development of toxicity, and encephalopathies, following small multiple doses (McNeill et al.) . The dose which affects the neurotransmitter system was in the range of 0.76 mg/g (in mice).
The specific activity of 18 F-FMISO prepared is in the range of 1-3 Ci/μmol. The physical material will be in the range of 2-6μg per patient. This radiotracer dose is far below the toxicity dose. In addition, animal acute toxicity studies have been performed, rats (n=3) were administered 2 mCi/Kg as a single dose. All rats tolerated this dose without toxicity on longer follow-up periods (5 days). This dose is ten-fold higher than the dose thus far studied.
EXAMPLE 9
PET Imaging Studies Using 18 F!FMISO
PET imaging studies were performed on two patients with nasalpharyngeal cancer (NPC). Each patient was positioned supine in the scanner so that the detector rings would span the entire tumor region. A 20-min attenuation scan was performed with a 4 mCi 68 Ge-ring source prior to tracer injection. After each patient had received 10 mCi of 18 F!FMISO, eight consecutive 15-min scans were taken. The total number of counts collected per scan was in the range of 15-30 million. Each patient was also administered 18 F!FDG to ascertain the tumor region.
In the first patient, 18 F!FMISO showed tumor uptake in the lymph node region (see FIG. 3) suggesting the tumor metastasized to lymph node is hypoxia. In the second patient, the recurrent primary tumor is hypoxic (see FIG. 4). This study demonstrates that 18 F!FMISO is able to detect primary or metastatic hypoxic tumors.
EXAMPLE 10
Synthesis of L-Threitol-1,4-di-p-tosylate-2,3-O-diacetylate (Compound 6)
A solution of L-threitol 1,4-di-p-tosylate (1 g, 2.3 mmole) was added dropwise with stirring over 5 min. at room temperature, to a solution of acetic anhydride (3 ml, 31 mmole) and BF 3 ,etherate (0.2 ml) in anhydrous ether (20 ml). The reaction mixture was stirred for 10 min., washed successively with 25% sodium acetate solution (10 ml) and water (25 ml×2), and dried over anhydrous sodium sulfate. The solvent was evaporated, and the residue was distilled under reduced pressure to give the acetylated compound. Yield 94%. The structure of the desired compound was confirmed by 1 H NMR, 13 C NMR and mass spectral data. 1 H NMR: 7.75 (d; J=8.3 Hz; 4H; Har.); 7.35 (d; J=8.3 Hz; 4H; Har.); 5.2 (t; J=3.2 Hz; 2H; H2, 3H); 4.2 (t; J=5 Hz; 4H; H1, 4); 2.5 (s; GH; 2CH 3 ar.); 2.0 (s; 6H; 2CH 3 ac.). 13 C NMR: 169.5(OCOCH3); 145.3 (C ar.); 132.2(C ar.); 129.9 (CH ar.); 127.9(Ch ar.); 68.3 (C2,3); 66.4 (C1, 4); 21.6 (CH 3 ar.); 20.4 (OCOCH 3 ). MS FAB, C22H26S2010)! m/z: 515(M + +1, 55); 455 (M + --OCOCH 3 , 8%); 342 (M + -tosylate, 100%).
EXAMPLE 11
Synthesis of 1-(2'-Nitro-1'-imidazolyl)-2,3 -O-acetyl-4-O-tosylbutanol (Compound 8)
2-Nitroimidazole (100 mg, 0.88 mmole) was dissolved in DMF (1 ml), cesium carbonate (289 mg) was added and the reaction stirred for 5 min at room temperature. Threitol 1,4-di-p-tosylate 2,3-diacetate (1.1 eq., 431.5 mg, 0.97 mmole) was added last, and the reaction was stirred at 80° C. for 1 hour. The reaction was filtered and the DMF removed in vacuo. The residue was chromatographed on alumina eluted with ethyl acetate/petroleum ether. The structure of resultant 1-(2'-Nitro-1'-imidazolyl)-2,3-O-acetyl-4-O-tosylbutanol, the fluoromisonidazole butanol analog, was confirmed by 1 H NMR and 13 C NMR. 1 H NMR: 7.85(d; J=8.2 Hz; 2Har.); 7.4(d; 2H; J=8.2 Hz; 2Har.); 7.15(d; 2H; J=2.9; H-imidazolyl); 5.4 (m; 1H; H2); 5.2 (m; 1H; H3); 4.95(dd; 1H; J=14.5, 3.5 Hz; H4a); 4.5(dd; 1H; J=14.5, 3.5 Hz; H4b) 4.3 (m; 2H; h1); 2.45(s; 3H; CH 3 tosyl); 1.98(s; 6H; 2CH 3 ac.). 13 C NMR 169.4 (OCOCH3); 146(Car.); 132(Car.); 130.1(CHar); 128.3(C-imidazolyl); 127.9(CH-imidazolyl); 127.4(CHar); 126.7(CH-imidazolyl); 69.3(C2,3); 67.1(C1); 49.3(C4); 21.6(CH3tosyl); 20.5(CH3ac.).
EXAMPLE 12
Synthesis of ( 18 F)Fluoromisonidazole butanol analogue (Compound 1B)
This compound can be prepared from 1-(2'-Nitro-1'-imidazolyl)-2,3-O-acetyl-4-O-tosylbutanol, KRYPTOFIX® 222-fluoride complex in acetonitrile as described for ( 18 F)FMISO synthesis. The ( 18 F) fluoromisonidazole butanol analog is usable for PET tumor imaging.
EXAMPLE 13
Radiosynthesis of 131 I Iodomisonidazole (Compound 1C)
5 mg of tosylmisonidazole was dissolved in 1 mL of acetone. Na 131 I (1 mCi in borate buffer) was added. The reaction mixture was heated at 80° C. for 1 hour. Radio-thin layer chromatographic (TLC) analysis showed two peaks with Rf values of 0.01 and 0.72. The first peak was free Na 134 I and the second peak was 131 I-iodomisonidazole. Radio-TLC indicated the desired product has 45% yield. The pure product was obtained after hydrolysis and then passed through a silica gel column and eluted with ether:petroleum ether:triethylamine (1:1:10%). This compound is useful therapeutically.
EXAMPLE 14
Synthesis of (2'-nitro-1'-imidazolyl)-2,3-isopropylidene-4-tosylbutanol (Compound 10)
A mixture of 1,4-ditosyl-2,3-isopropylidene-D-threitol (ET) (0.47 g, 1 mmol), 2-nitroimidazole (0.1 g, 0.9 mmol), and cesium carbonate (0.29 g, 0.9 mmol) in 10 ml of dry dimethylformamide (DMF) was heated at 60° C. for 1 h. The reaction was then cooled and DMF was removed under reduced pressure. The residue was taken up in ethyl acetate and filtered. Removal of ethyl acetate in vacuo produced a yellow oil which was chromatographed on silica gel, eluted with petroleum ether/ethyl acetate (gradient form 10% to 70%) to afford a white solid (0.27 g, 0.63 mmol, 70% yield). The structure of the product was determined by 1 H and 13 C NMR and mass spectral data. HPLC showed the retention times of the title compound to be 12.45 min, and the ET compound to be 14.8 min (UV 254 nm, Brownlee C-18 5μ reverse phase column, 4.6×100 mm eluted with water/methanol, 0-80%, at a flow rate of 1.0 ml/min).
EXAMPLE 15
Radiosynthesis of 18 F!fluoroerythro-2-nitroimidazole (FETNIM) (COMPOUND 9)
18 F!Fluoride was produced in the cyclotron facility (42 MeV, Cyclotron Corp., Berkeley, Calif.) at the University of Texas M.D. Anderson Cancer Center by proton irradiation of enriched 18 O-water in a small-volume titanium target. The target was filled with 2 ml of 18 0! water. Aliquots containing 400-500 mCi of 18 F activity after 1 hour beam time (12 μA current) was combined with KRYPTOFIX®-2,2,2 (26 mg) and anhydrous potassium carbonate (4.6 mg), heated under reduced pressure to remove 18 0! water, and dried by azeotropic distillation with acetonitrile (3×1.5 mL). The tosyl analogue of 2-nitroimidazole (Compound 10, 20 mg), prepared from (Compound 10) was dissolved in acetonitrile (1.5 mL), added to the KRYPTOFIX®-fluoride complex, and then warmed at 95° C. for 10 min. After cooling, the reaction mixture was passed through a silica gel Sep-pak column (Whatman Lab, Clifton, N.J.) and eluted with ether (2×2.5 mL). The solvent was evaporated and the resulting mixture was hydrolyzed with 2N HCl (1 mL) at 105° C. for 10 min. The mixture was cooled under N 2 and neutralized with 2N NaOH (0.8 mL) and 1N NaHCO 3 (1 mL). The mixture was passed through a short alumina column, a C-18 Sep-Pak column, and a 0.22-μm Millipore filter, followed by eluting 6 mL of 10% ethanol/saline. A yield of 70-80 mCi of pure product was isolated (20-30% yield, decay corrected) with the end of bombardment (EOB) at 70 min. HPLC was performed on a Brownlee (5μ reverse phase) column, 4.6×100 mm, with water/methanol, 0×80%, using a flow rate of 1 mL/min. The no-carrier-added product corresponded to the retention time (3.11 min) of the unlabeled FETNIM under similar conditions. The retention time before hydrolysis of compound 9 was 8.94 min. The radiochemical purity was greater than 99%. Under the UV detector (254 nm), there were no other impurities. A radio-TLC scanner (Bioscan, Washington, DC) showed a retardation factor of 0.3 for the final product using a silica gel plate G/UV 254, 5×20 cm (Whatman, Anaspec, Mich.), eluted with chloroform:methanol (7:3), which corresponds to the unlabeled FETNIM. In addition, KRYPTOFIX®-2,2,2 was not visualized (developed in iodine chamber) on the silica gel-coated plate using 0.1% (v/v) triethylamine in methanol as an eluant. The specific activity of 18 F!FETNIM ranged from 1 to 2 Ci/μmol based upon UV and radioactivity detection of a sample of known mass and radioactivity.
EXAMPLE 16
PET Imaging Studies Using 18 F!FETNIM
PET imaging was performed with a positron camera (Positron Corporation, Houston, Tex.). The tomograph has a field-of-view of 42 cm on transverse and 12 cm on coronal planes. The axial resolution on the reconstructed plane is 1.2 cm. Twenty-one transaxial slices separated by 5.2 mm were reconstructed and displayed in standard uptake value (SUV) which measures the ratio of tissue radiotracer uptake to that of the whole body uptake for each scan.
Three male New Zealand white rabbits each weighing 3 kg were inoculated at a single site in the right buttock area with a 0.5 ml suspension of minced VX2 tumor fragments (10 6 cells/rabbit). The tumors are maintained through serial animal passage and are available from the Department of Veterinary Medicine (The University of Texas M.D. Anderson Cancer Center, Houston, Tex.). When the tumor size reached 2 cm by two weeks after inoculation, each rabbit was administered 4 mCi of 18 F!FETNIM. A 20 minute attenuation scan was performed with a 4 mCI 68 Ge-ring source prior to tracer injection. Each rabbit was supine in the scanner so that the detector rings would span the entire lumbar region. Eight consecutive 10 minute scans were acquired. There was a 5 minute wait between scans for data transfer. The total number of counts collected per scan was in the range of 3-6 million.
The coronal, transaxial and sagittal views of a PET image of a tumor-bearing rabbit 1 hour after administration of 18 F!FETNIM is shown in FIG. 7. The rabbit was scanned from cranial to caudal direction. The tumor can be visualized at one hour postinjection of 18 F!FETNIM. The SUV value of the tumor was greater than 10 .
EXAMPLE 17
Autoradiographic studies of 18 F!FETNIM in tumor-bearing rats
Female Fischer 344 mammary tumor-bearing rats (n=3) after receiving 18 F!FETNIM (2 mCi, iv) were sacrificed at 1 h. To ascertain the metabolic and hypoxic character of the tumor, one rat was administered 18 F!fluorodeoxyglucose and another rat was given 18 F!fluoromisonidazole (2 mCi, iv). The rats were sacrificed at 1 hour postinjection. The rat body was fixed in a carboxymethyl cellulose (4%) block. The frozen body in a block was mounted to a cryostat (LKB 2250 cryo-microtome, Ijamsville, Md.) and 40 μm coronal sections were made. The section was freeze dried, then mounted on a x-ray film (X-Omat AR, Kodak, Rochester, N.Y.) for 24 hours.
In vivo autoradiographic studies in mammary tumor-bearing rats indicated that the tumor could be visualized 1 hour postinjection. However, in the center region of the tumor, there was a lack of uptake of 18 F!FETNIM, suggesting tissue necrosis (FIG. 8). The necrotic region can be verified from the photograph. The autoradiogram of 18 F!FDG indicated that the tumor was metabolically active. The distribution of 18 F!FDG in a tumor-bearing rat was different from 18 F!FETNIM and 18 F!FMISO. The intestines and colon showed high uptake in 18 F!FETNIM and 18 F!FMISO. However, the medullary of the kidney area had higher uptake in the 18 F!FETNIM specimen.
EXAMPLE 18
Polar Graphic Oxygen Needle Probe Measurements
To confirm hypoxic tumors detected by imaging, intratumoral pO 2 measurements were performed using the Eppendorf computerized histographic system. Twenty to twenty-five pO 2 measurements along each of two to three linear tracks were performed at 0.4 mm intervals on each tumor (40-75 measurements in total). Tumor pO 2 measurements were conducted on 3 tumor-bearing rats and rabbits. Using an on-line computer system, the pO 2 measurements of each track were expressed as absolute values relative to the location of the measuring point along the track, and as the relative frequencies within a pO 2 histogram between 0 and 100 mmHg with a class width of 2.5 mm.
Intratumoral pO 2 measurement of the mammary tumors and VX2 tumors indicated that both tumor oxygen tensions ranged from 3.2 to 6.0 mmHg; the normal muscle oxygen tension was 30-40 mmHg. Both tumors are hypervascular in their viable region and hypovascular in their central region. Both tumor-bearing animal models are suitable for the evaluation of tumor hypoxia.
EXAMPLE 19
In Vivo Biodistribution of 18 F!FETNIM in Tumor-Bearing Rats
Female Fischer 344 rats (250-275 g) (Harlan, Inc., Indianapolis, Ind.) were inoculated with mammary tumor cells in the lumbar area using a 13762 tumor cell line (s.c. 10 5 cells/rat). After 14 days, a tumor size of 1-2 cm was observed. Three groups of rats (N=3/group) were anesthetized with ketamine (10-15 mg/rat). The 18 F-FETNIM reconstituted in 5% ethanol/saline was given to rats (10 μCi/rat, iv) and tissue distribution was conducted at 1h, 2h and 4h intervals. The tissues were excised, weighed and counted for radioactivity. The percent of injected dose per gram of tissue weight was determined.
The tissue distribution of 18 F!FETNIM in the tumor-bearing rats is shown in Table 2. Bone had high affinity for ionic fluoride, the bone uptake value did not alter, suggesting the in vivo stability of 18 F!FETNIM. The tumor/muscle, tumor/blood and tumor/liver count density ratios showed increases with time (FIG. 9), the tumor-to-blood count density being 8.0±2.42 at 4 hour postinjection of 18 F!FETNIM. This increased tumor-to-background ratio suggests that 18 F!FETNIM has the potential to detect tumor hypoxia.
TABLE 2__________________________________________________________________________Biodistribution of .sup.18 F! Fluoroerythronitroimidazole inTumor-Bearing Rats.sup.1(Percent of Injected Dose/Gram Weight; N = 3/Time Interval)TIME 1 HOUR 2 HOUR 4 HOUR__________________________________________________________________________BLOOD 0.3493 ± 0.02173 0.1950 ± 0.02828 0.0993 ± 0.01266LUNG 0.3577 ± 0.00723 0.2107 ± 0.05713 0.1027 ± 0.02122LIVER 0.4530 ± 0.01493 0.3123 ± 0.08225 0.1843 ± 0.02458SPLEEN 0.3183 ± 0.02011 0.2013 ± 0.05918 0.0953 ± 0.01401KIDNEY 0.8860 ± 0.00424 0.5145 ± 0.02334 0.4663 ± 0.06866BONE 0.2570 ± 0.14001 0.0810 ± 0.00424 0.0753 ± 0.01570MUSCLE 1.2600 ± 0.08627 0.2670 ± 0.09036 0.1377 ± 0.01893TUMOR 0.7957 ± 0.20358 0.5516 ± 0.15818 0.8113 ± 0.33773TUMOR/BLOOD 2.2900 ± 0.59940 2.4100 ± 0.56719 8.0200 ± 2.42000TUMOR/MUSCLE 0.6602 ± 0.26659 2.1100 ± 0.34679 5.9200 ± 2.24000TUMOR/LIVER 1.7600 ± 0.44151 1.7700 ± 0.25608 4.3300 ± 1.31000__________________________________________________________________________ .sup.1 13762 cell line was inoculated to rats (s.c. 10.sup.5 cells/rat). When tumor size reached 1-2 cm, each rat was administered 10μCi tracer
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It is understood that equivalents of the following claims involve simple substitution of analogous chemicals and methods well known to those of skill in the art.
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The present invention involves a rapid synthesis of 18 F-FMISO and analogs thereof. New precursors such as 1-(2'-nitro-1'-imidazolyl)-2-0-acetyl-3-0-tosylpropanol, glycerol-1,3-ditosylate-2-0-acetylate, 1-(2'-nitro-1'-imidazolyl)-2,3-0-diacetyl-4-0-tosylbutanol and threitol 1,4-di-tosylate-2,3-0-diacetylate, are also important aspects of the invention.
A further aspect of the invention is the development of a hydrophilic PET ligand to image tumor hypoxia. Erythrotosyl analogue of 2-nitroimidazone (Ts-ETNIM) was prepared from a mixture of 2-nitromidazole, ditosylthreitol and cesium carbonate at 60° C. for 1 hr. Ts-ETNIM was isolated at 70% yield. 18 F!fluoroerythronitroimidazole (FETNIM) was then prepared from Ts-ETNIM and K 18 F/kryptofix®. The yield for 18 F!FETNIM was 26-30% (60 min, decay corrected). Results of biodistribution and PET studies indicate that 18 F!FETNIM has the potential to detect tumor hypoxia and is indicated to be less neurotoxic.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to status monitoring systems such as burglar or fire alarm systems, and more particularly to status monitoring systems employing multiple sensors and special logic to reduce the probability of false alarms.
2. The Prior Art
Status monitoring systems using multiple sensors and logic circuitry to discriminate against false alarms are known to the art. Such logic circuitry generally accomplishes its function of avoiding false alarms by generating an alarm signal only if two or more of the sensors generate response signals within a predetermined interval of time. An example of such a system is found in U.S. Pat. No. 4,195,296, dated Mar. 25, 1980, issued to Galvin.
A problem with existing multiple-sensor status monitoring systems is the failure of such systems to give a trouble signal if a sensor malfunctions. A sensor malfunction may take the form either of a failure to respond to a stimulus or of a spurious response in the absence of a stimulus. The first kind of malfunction--failure to respond at all--can result in a failure to sound the alarm when the status being monitored changes. The second kind of malfunction--a spurious response--can result in a false alarm. Neither kind of sensor malfunction produces a trouble warning in existing multiple-sensor status monitoring systems, and hence there is no way to know that one or more sensors have malfunctioned until one or the other kind of system failure occurs.
Moreover, even if there is a system failure, if a sensor is malfunctioning intermittently there is no way to determine which of the various sensors is the cause of the trouble, and hence troubleshooting such a system failure is virtually impossible.
A partial solution to the problem of generating a trouble warning in the event of the first kind of sensor malfunction--failure to respond at all--is disclosed in U.S. Pat. No. 3,801,978, issued Apr. 2, 1974 to Gershberg. The Gershberg patent discloses an intrusion alarm system comprising the combination of a microwave motion sensor and an ultrasonic motion sensor. False alarms are avoided by activating an alarm only if both sensors simultaneously signal the presence of an intruder. The alarm is also activated if either sensor fails to function, but only a complete failure of either the microwave or the ultrasonic sensing signal causes alarm activation. So long as both sensors are radiating sensing signals, the failure of either sensor to respond to a proper stimulus will not be detected. A further limitation of the Gershberg system is that even in the event of a complete failure of one of the sensing signals, the Gershberg system does not identify the sensor that has failed.
Even the limited failure-detecting ability of the apparatus disclosed by Gershberg only works with an energy radiating sensor such as a microwave or ultrasonic motion detector. A passive sensor is not adaptable to being monitored by the Gershberg apparatus, and hence a failure of a passive sensor will not be detected by such apparatus.
A spurious response in the absence of a proper stimulus is easy to detect in a single-sensor status monitoring system because such a response activates the system's alarm. Since there is only one sensor, locating the fault is relatively simple once it has been determined that the alarm was a false alarm. However, a multiple-sensor system--even the Gershberg system--does not activate its alarm if it detects a response signal from only one sensor. A spurious response signal from any one sensor, regardless of whether the signal is continuous or intermittent, is simply ignored. Hence, since there is neither an alarm nor a trouble warning, the defective sensor will continue to malfunction and system performance will be degraded.
A partial solution to the problem of detecting a spurious response from one sensor is proposed in the multiple-sensor system disclosed in the Galvin patent. The Galvin system has logic circuitry to generate a first alarm signal if any one sensor is activated and to generate a second alarm signal only if at least two sensors are activated within a predetermined interval of time. Thus, if the first alarm, but not the second alarm, sounds, once it has been determined that the alarm was false, it will be apparent that one of the sensors has given a spurious response. However, in Galvin's apparatus there is no way to determine which sensor has caused the trouble.
It will be apparent from the foregoing that there is a need for a multiple-sensor status monitoring system having the ability to warn of a sensor malfunction either of the first kind or of the second kind and to identify the malfunctioning sensor. The present invention satisfies this need.
SUMMARY OF THE INVENTION
The present invention resides in a multiple-sensor status monitoring system. The system has a plurality of sensors that each provide a primary signal in response to a stimulus. A storage means coupled to each sensor keeps an electronic record of the occurrence of a primary signal from that sensor. In addition, each sensor is connected to one of a plurality of timers, and each timer provides a timing output signal of fixed duration in response to a primary signal from any of the sensors connected to that timer. A logic means connected to the timers generates a status change signal if a timing output signal from one timer overlaps such a signal from any other timer. Thus, an alarm is sounded only if at least two sensors provide primary signals within a predetermined time of each other.
A sensor malfunction manifested by the generation of spurious responses from a sensor can be detected by examining the record kept by the storage means of primary signals provided by each sensor. A sensor malfunction manifested by a failure to respond to a valid stimulus can be detected by deliberately introducing a stimulus throughout the area being monitored and then determining from the record which sensors failed to provide primary signals in response to the stimulus.
In one embodiment, the storage means takes the form of a plurality of silicon-controlled rectifiers ("SCRs"), one for each sensor, wired into simple latch circuits. A primary signal from a given sensor latches the SCR associated with that sensor; once latched, the SCR stays latched until it is manually reset. Indicator means associated with each latch may take the form of a light-emitting diode ("LED") to indicate latching.
The timers and logic circuit prevent a status change alarm signal from being generated unless at least two different sensors provide primary signals within a predetermined period of time. Some of the sensors are connected to one timer and some to each of the other timers. If a sensor provides a primary signal, then the timer to which that sensor is connected generates a timer output signal having a duration of about three minutes. If a sensor connected to another timer also provides a primary signal, then that other timer also generates a timer output signal. The logic circuit generates a status change alarm signal only if output signals from both timers overlap in time. During initial system design, the sensors are laid out such that a bona fide change in status will of necessity cause primary signals to be provided by at least two different sensors, not all of which are connected to the same timer. In this way, the probability of false alarms is greatly reduced because a spurious signal from any one sensor will not sound the alarm, but signals from two sensors within three minutes of each other will sound the alarm.
In another embodiment, a circuit is provided that can "freeze" all the latches and timers, rendering them insensitive to primary sensor signals. This feature is desirable if the invention is embodied in a burglar alarm having a control panel located within the protected area. Typically, a burglar alarm is only activated during hours when the premises being guarded are deserted. When the premises are opened, it is necessary for a person to enter the protected area and proceed to the control panel to shut off the alarm. By making such an entry and walking through the protected area to the control panel, the person will of necessity activate one or more of the sensors, but it is not desirable for a record of such activations to be stored by the latches. Accordingly, the freeze circuit can be activated so that the person can enter the premises and shut off the alarm without either sounding the alarm or causing a record of sensor activations to be stored in the latch circuits.
In still another embodiment, an exit delay circuit is provided. This circuit "freezes" the timers and latches for a predetermined interval of time after the alarm system has been turned on, so that the person who turns the system on has time to leave the protected area without setting off the alarm.
It will be appreciated from the foregoing that the present invention represents a significant advance in the field of multiple-sensor status monitoring systems. In particular, a status monitoring system incorporating this invention gives a trouble warning in the event any of its sensors gives a spurious response and identifies which sensor or sensors have given such responses. The system is also capable of detecting and identifying non responsive sensors during system testing.
Other aspects and advantages of the present invention will become apparent from the following more detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a multiple-sensor status monitoring system according to the invention;
FIG. 2 is a schematic diagram of the circuitry contained within box 2 of FIG. 1;
FIG. 3 is a block diagram of a multiple-sensor status monitoring system that is similar to the system shown in FIG. 1 except for the addition of an exit delay circuit and a circuit to prevent sensor activations if a first alarm signal has been generated;
FIG. 4 is a schematic diagram of the circuitry contained within box 2A of FIG. 3;
FIG. 5 is a block diagram of a multiple-sensor status monitoring system according to the prior art; and
FIG. 6 is a block diagram of the multiple-sensor status monitoring system of FIG. 5, with circuitry embodying the present invention added thereto as an improvement.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Multiple-sensor status monitoring systems with logic for avoiding false alarms give no warning of the failure of any one sensor. The present invention provides a multiple-sensor status monitoring system that stores and displays a record of the primary signals provided by each sensor but sounds no alarm unless two or more different sensors generate primary signals within a predetermined interval of time.
A multiple-sensor status monitoring system 100 embodying the present invention has sensor inputs 101, 103, 105 and 107, as shown in FIG. 1. Each input is configured for connection to a sensor, such as a normally-closed switch, that presents a closed circuit to ground when said sensor is not activated and an open circuit when said sensor is activated, the primary signal provided by such a sensor being the interruption of the connection between ground and the input to which said sensor is connected. It will be apparent to those skilled in the art, however, that said inputs could be configured to accept other kinds of primary signals if desired.
Sensor input 101 is connected to a latch circuit 109 through a conductor 111. In similar fashion, sensor inputs 103, 105 and 107 are connected to identical latch circuits 113, 115 and 117 through conductors 119, 121 and 123, respectively.
Typical latch circuit 109, shown schematically in FIG. 2, has a silicon-controlled rectifier ("SCR") 125 that is held quiescent by bias resistors 127, 129 and 131 until a sensor connected to input 101 provides a primary signal to the gate of SCR 125, and then SCR 125 begins to conduct, causing a voltage to develop across resistor 133 in the cathode circuit of SCR 125. Said voltage is applied to the base of transistor 135, and emitter current begins to flow. Said emitter current flows through current limiting resistor 139 and light-emitting diode ("LED") 137, and LED 137 begins to emit light. Once SCR 125 begins to conduct, it continues to conduct regardless of the status of the sensor connected to input 101, and hence LED 137 remains lit, thereby giving a continuous indication that a primary signal was received from said sensor.
In like manner, latch circuits 113, 115 and 117 are triggered by primary sensor signals occurring at inputs 103, 105 and 107, respectively, and LEDs associated with said latch circuits are illuminated in similar fashion.
Input 101 is connected to timer 145 through conductor 147, and input 103 is connected to timer 145 through conductor 149. A primary signal at input 101 is applied to a one-shot multivibrator comprising transistor 151, resistor 153, and capacitor 155, causing the multivibrator to produce a short output pulse that is applied to pin 2 of a pulse generator comprising a type 555 integrated circuit 157, resistor 159, capacitor 161, and time constant determinants resistor 163 and capacitor 165. In like manner, a primary signal at input 103 is applied to an identical one-shot multivibrator comprising transistor 167, resistor 169 and capacitor 171, causing a short output pulse to be applied to pin 2 of integrated circuit 157.
Upon receiving a short input pulse from either of said multivibrators, integrated circuit 157 provides at conductor 173 a timer output signal having a duration governed by resistor 163 and capacitor 165. In similar fashion, inputs 105 and 107 are connected through conductors 175 and 177, respectively, to identical timer 179, and a primary signal from either input 105 or 107 results in a timer output signal at conductor 181.
Although the duration of the timer output signals is not critical, for a typical burglar alarm installation a duration of about three minutes gives good results.
Timer output signals from timers 145 and 179 are applied to logic block 183. Logic block 183 includes NAND gate 185, resistors 187 and 189, and output transistor 191. When the circuit is at rest, the output of gate 185 is high, causing transistor 191 to appear as a closed circuit to ground at output 193. A timer output signal from only one of timers 145 and 179 will not change this status, but if at any moment timer output signals from both said timers are simultaneously present at the inputs to gate 185, then transistor 191 will appear as an open circuit at output 193, and this appearance as an open circuit constitutes a status change output signal.
The probability of a false alarm is reduced by causing transistor 191 to switch to an open circuit from a closed circuit to ground only if two different sensors provide primary signals within a predetermined time set by time constant components 163 and 165 and by the comparable components in timer 179. If a sensor malfunctions so as to provide a continuous primary signal, the multivibrator that couples that sensor to its associated timer blocks such a continuous signal from interfering with normal operation of the timer and the other sensors connected thereto.
An embodiment of the invention having certain additional features that are especially desirable in burglar alarm systems is shown in block form in FIG. 3. This embodiment is similar to that shown in FIG. 1 and for convenience components in FIG. 3 that are similar to components in FIG. 1 are assigned the same reference numerals, analogous but changed components are assigned the same reference numerals accompanied by the letter "A", and different components are assigned different numerals.
A multiple-sensor status monitoring system 100A has sensor inputs 101, 103, 105 and 107 connected to identical latch circuits 109A, 113A, 115A and 117A through conductors 111, 119, 121 and 123, respectively.
Latch circuit 109A, shown schematically in FIG. 4, is similar to latch circuit 109 as shown in FIG. 2 except that cathode resistor 133 of SCR 125, instead of connecting directly to ground, connects through diode 195 to exit delay circuit 197 through conductor 199. Identical latch circuits 113A, 115A and 117A are also connected to exit delay circuit 197 in a like manner.
Exit delay circuit 197 has input 201, type 555 IC 203, time determinants 205 and 207, transistor 209, and resistor 211. Initially, input 201 is kept at ground level, causing output pin 3 of IC 203 to be at ground level. Transistor 209 is cut off, no current can flow through conductor 199, and latches 109A, 113A, 115A and 117A are prevented from latching whether or not primary sensor signals are presented to their inputs. If a positive voltage is applied to input 201, output pin 3 of IC 203 goes to a positive level after a period of time determined by components 205 and 207. Once output pin 3 goes to a positive level, transistor 209 switches on, providing a path from conductor 199 to ground and enabling latches 109A, 113A, 115A and 117A to latch in response to primary sensor signals.
Timer circuit 145A, shown schematically in FIG. 4, and identical timer circuit 179A are similar to timers 145 and 179 as shown in FIGS. 1 and 2, except that reset pin 4 of IC 157 is used to control operation of timer 145A and reset pin 4 of the corresponding IC in timer 179A is used to control operation of timer 179A. Reset pins 4 of both ICs are connected to output pin 3 of IC 203 in exit delay circuit 197, and, as long as said pin 3 remains at ground level, timers 145A and 179A cannot function. Only after said pin 3 goes to a high level can either timer generate a timer output signal in response to primary signals from the associated sensors.
Exit delay circuit 197, then, activates the system a predetermined time after a positive voltage is applied to input 201. This makes it possible for a person to turn the system on at a control panel located within the protected premises, and then to leave the building without setting off the alarm.
Sensor inputs 101, 103, 105 and 107 are also connected to freeze circuit 213 through diodes 215, 217, 219 and 221, respectively. So long as input 223 to freeze circuit 213 is kept at ground level, transistor 225 remains cut off and has no effect on the performance of the system. If a positive voltage is applied to input 223 and from there to the base of transistor 225 through resistor 227, transistor 225 turns on, effectively grounding the cathodes of diodes 215, 217, 219 and 221. Grounding said cathodes has the effect of shorting inputs 101, 103, 105 and 107 to ground and thereby rendering the system insensitive to primary sensor signals applied to any of said inputs. This circuit is useful to prevent activation of the alarm system when a person desires to walk through the protected area to turn off the system. By applying a positive voltage to input 223, the system is rendered insensitive to primary sensor signals; however, any latches that have previously been latched remain latched even though freeze circuit 213 has been activated, so that the operator can tell by observing the LEDs which of the sensors provided primary signals during the hours the system was in operation. This information tells which sensors have given spurious responses and makes quick, efficient repair possible.
After the operator has observed which LEDs are illuminated, the system is turned off by removing the positive enabling voltage from input 201. If it is desired to test the sensors for proper operation, switch 229 is closed by the operator, enabling the latch circuits, but not the timers, to function. Then a stimulus is deliberately introduced throughout the protected area, and the operator observes the LEDs to see which ones are lit. If a LED remains unlit, the operator knows that the associated sensor failed to respond to the stimulus, and repairs can be effected.
A particularly useful embodiment of the present invention comprises a unit that can be retrofitted to an existing status monitoring system, such as a burglar alarm. Such an existing, prior art status monitoring system 500, illustrated in block form in FIG. 5, has sensors 501, 503, 505 and 507 connected to sensor input 509 of alarm panel 511 and sensor 513 connected to special sensor input 515. When an operator desires to activate the system, switch 517 is turned to position #3 and an active signal is thereby applied to LED 519 through connection 521 to indicate that the system is active. An internal timing element (not shown) delays actual system activation for a short period of time to permit the operator to leave the premises without setting off the alarm, and thereafter, if any of sensors 501, 503, 505 or 507 provides a primary signal by momentarily becoming an open circuit, an alarm output signal is provided at terminal 522 to activate a suitable alarm such as alarm bell 523.
A primary signal from sensor 513 has a different effect. If sensor 513 provides a primary signal by becoming an open circuit, an alert signal device 525, such as a buzzer or warning light, is activated by an alert signal at output 527, and unless the alarm system is turned off within a predetermined time thereafter, alarm 523 is sounded. However, once sensor 513 has provided a primary signal, the system is rendered unresponsive to primary signals from any of the other sensors. Sensor 513 is so located that the operator activates it upon entering the building, and so long as the operator proceeds directly to panel 511 and shuts off the system within said predetermined time, alarm 523 will not be sounded. The system is turned off by turning switch 517 to position #2 (standby) or #1 (power off).
Multiple-sensor status monitoring system 100A can be connected to existing burglar alarm system 500 to form a complete multiple-sensor burglar alarm system having all the advantages of the present invention, as shown in FIG. 6. Sensors 501, 503, 505 and 507 are disconnected from terminal 509 of burglar alarm 500 and are instead connected to inputs 101, 103, 105 and 107 of monitoring system 100A. Terminal 521 of burglar alarm 500 is connected to input 201 of monitoring system 100A, so that an active signal at terminal 521 starts the exit delay timer of monitoring system 100A. Terminal 527 of burglar alarm 500 is connected to input 223 of monitoring system 300, so that an alert signal from burglar alarm 500 activates the freeze circuit of monitoring system 100A. Output 193 of monitoring system 100A is connected to sensor input 509 of burglar alarm 500. Finally, operating power for monitoring system 100A can be drawn from power terminals 529 and 531 of burglar alarm 500.
When the complete multiple-sensor burglar alarm system is in operation, an operator can activate the system, as before, by setting switch 517 to position #3. The operator then has a short interval of time within which to leave the protected area without setting off the alarm. Thereafter, if both timer 145A and timer 179A of monitoring system 100A produce overlapping timer output signals, a status change signal is applied to input 509 and the alarm sounds. The latches and LEDs of monitoring system 100A tell which sensors have provided primary response signals. When the operator returns and wishes to shut off the complete system, sensor 513 is activated, causing an alert signal to be applied to input 223 and thereby rendering system 100A insensitive to any further sensor activations.
It will be apparent from the preceding description that this invention provides a multiple-sensor alarm system having not only the ability to avoid false alarms but also the ability to warn of sensor failures and to identify the failed sensor or sensors for repair or replacement. Such a multiple-sensor system is provided either as a stand-alone system or as a retrofit to be added to an existing alarm system not having these desirable features.
Although one specific embodiment of this invention has been described and illustrated, it is to be understood that the invention is not to be limited to the specific forms or arrangements of parts so described and illustrated, and that various changes can be made within the scope of the invention. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.
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A multiple-sensor status monitoring system for monitoring the status of an area while avoiding false alarms and detecting and identifying faulty sensors. The system uses a timer and logic to avoid false alarms by generating an alarm signal only if two sensors give a response within a preselected interval of time. The system employs latching storage elements to keep a record of which of the sensors have made spurious responses, and a visual display to give a trouble warning respecting those sensors.
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FIELD OF THE INVENTION
The present invention pertains to a container handling apparatus, operated as special equipment which is independent from the type of machine used. This invention also pertains to secondary devices which are used to adapt this equipment to a crane, a gantry or any other lifting equipment. This invention applies particularly to the handling of containers which are held by reinforced corner fittings, using a spreader suspension system.
BACKGROUND OF THE INVENTION
The invented apparatus is designed to meet the requirements of the various container handling operations:
The container must be orientated in order to position it on a transportation vehicle, a boat or another carrier.
The overall dimensions of the container itself must be taken into consideration so as to make allowances for the bulk of the container.
The container should not be excessively tilted in the direction of its longitudinal axis. Excessive tilting, such as those resulting from a bad weight distribution in the container, could prevent the correct loading of the container inside a ship for instance.
Likewise, the axis of the hanging system should remain vertical throughout the container handling operations.
In order to solve the above problems, two types of equipment have been designed.
In the first type of equipment, the container orientation system hangs from the lifting cables and is directly connected to the spreader. This solution has the disadvantage of limiting the hanging pattern to a square in which the diagonal is equal to the width of the spreader, since its overall dimensions cannot exceed the container's dimensions regardless of its orientation. Obviously, the container will remain stable only as long as its center of gravity is located inside that square. This condition being met, the loading operation of the container is generally off-centered and the cables are subjected to various loads which increase the tilting of the container, due to cable elongation. It becomes increasingly difficult to compensate for the excessive tilting by taking up the length of the cables, as the cable loads and cable elongation vary with the container's orientation. Furthermore, it is possible to take up the length of the cables only after the latter have reached a given elongation, and after the container has been put in a wrong position. Finally, the incidental torques overload the cables and the machine's elements by creating cambering and twisting forces within the frame.
In the second type of equipment, the orientation of the system is such that it hangs directly from the machine's frame. By correctly routing the cable on a number of lazy or idle pulleys, it is possible to keep the overall dimensions of the hanging system on the spreader within a rectangle whose length greatly exceeds the width, thus reducing the effects of the above disadvantages but without eliminating them. However, the cables follow the rotating motion of the container, which causes the cable system to become twisted, and it is not possible to obtain an orientation exceeding an angle of 90° on either side of a zero position.
SUMMARY OF THE INVENTION
The present invention aims at obtaining a container handling apparatus which offers the advantages of both popular types of equipment, while eliminating their disadvantages.
The container handling apparatus designed according to the specification of the invention includes four lifting cables, to the end of which the container orientation system is attached. This apparatus is characterized by the fact that the lower element of this rotating system includes two frames which respectively support a crown and four rollers. A four load receiver assembly is located between these frames, while four rollers are mounted so as to roll in a frame which is longitudinally attached to the container's support, following the longitudinal or long axis of the latter. It is therefore possible for the rotating device to move along the long axis with reference to the container. The longitudinal motions of this rotating device are automatically controlled by at least one cylinder or any other common device, such as a drive chain or a rack, driven by a reduction motor, based on the load measurements given by the receivers.
According to another specification of the invention, the four rollers and the four receivers define a quadrilateral whose center coincides with that of the quadrilateral defined by the four cables attaching points to the rotating device.
According to another specification of the invention, the apparatus is equipped with an electronic device which compares the load measurements given by the four receivers, and controls the activation of the various means which move the rotating device as long as the difference, between the various loads indicated by the receivers, exceeds an acceptable preset value.
According to another specification of the invention, the spreader attaches to the container's support with pins at one end, and with two cylinders or other popular remote devices at the other end, which allows the tilting of the container's support along the long axis of the spreader, in the case when this support has to be attached to a container resting on a slanted surface.
The container handling cranes are usually equipped with a gantry frame, an orientation crown, a rotating plate supporting the ballast weights, the mechanisms and a post, a plate, a boom pinned to the plate, as well as four lifting cables which are routed from a hoist and along the boom around lazy pulleys, before attaching to the container's orientation mechanism. This type of crane is characterized by the fact that it includes two lift drums which respectively wind up two cables that drop to the rotating device after being routed through four lazy pulleys. Each one of these lazy pulleys are approximately located on one angle of a square, one diagonal of which is parallel with the boom's axis as seen from the top, whereas the other diagonal is perpendicular to the axis of the boom. Two cables issued from a same drum are routed through two pulleys located on a same diagonal of the square.
According to another specification of the invention, the two pulleys which are mounted along the diagonal which is parallel with the boom's axis have an adjustable mount and can be mounted in alignment with the others. This mounting may be performed after displacing the two above mentioned pulleys and removal of the rotating device.
According to another specification of the invention, the lifting cables lazy pulleys are supported by a small boom which is jointed on one end of the boom and held in the back by a pull-rod which is parallel with the axis of the boom, so that this small boom, its span wire and the boom, define four sides of a parallelogram.
The container handling gantry designed according to the specifications of the invention, includes the following elements: two bearings supporting a beam defining the motion of a carrier, and four lifting cables originating in the carrier supported hoists and attached to the equipment so as to allow the orientation of the container. This gantry is characterized by the fact that it includes two lift drums whose respective axis are perpendicular, and respectively allowing the winding of two cables which drop to the rotation device, and whose section approximately defines a square or a diamond including one diagonal which is parallel to the beam's axis, and another one which is perpendicular to this long axis.
The attached, schematic drawings are intended to give a better understanding of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation of the apparatus and of its orientating device.
FIG. 2 illustrates a cross-section of this equipment's rotating apparatus, following a vertical plane which falls across the container.
FIG. 3 is a general side view of a crane built to the specifications of the invention.
FIG. 4 is a schematic, elevation view showing part of the routing of the cables along the crane.
FIG. 5 is a schematic elevation view showing the routing of the cables along the small boom of the crane.
FIG. 6 is a plane view of the small boom of the crane.
FIG. 7 is a general view of a gantry built to the specifications of the invention.
FIG. 8 is a top view indicating the layout of the lift drums and cables of the gantry of FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates the container and its orientation device. The device includes four lifting cables 1, 2, 3, 4 each of which are respectively attached to one of four points 5, 6, 7 and 8 respectively of the fixed part 9 of a rotating device 10 which is provided to orientate the container 11. These four points are respectively located on the corners of a square whose diagonal is approximately equal to the width of the spreader 12. The rotating part 13, of the rotating device 10, which rotates with reference to the fixed part 9, is rigidly mounted with a toothed crown 14 meshed with a driving gear which is mounted in the reduction motor 15 of fixed part 9. These elements 14 and 15 are part of a remote control orientation mechanism.
The rotating part 13, illustrated on FIG. 2, includes a lower frame 16 supporting the toothed crown 14, and an external frame 17 supporting four parallel axis rollers 18. The external frame 17 is vertically supported by the internal frame 16, through four load receivers 19 which are located in the angles of the frames.
The center of the square defined by the four attachment points 5, 6, 7, 8 coincides approximately with the center of the square or rectangle defined by the four rollers 18.
Appropriate means, not represented, have been provided to guide the frames 16 and 17, and to retain the receivers 19 in the correct position.
A secondary frame 20 is attached on top of the spreader 12, and includes two side-rails 21 which are supported by the rollers 18. A reciprocating hydraulic cylinder 22, as shown in FIG. 1 extends parallel to the rails 21, or any other suitable control device, is attached between the secondary frame 20 and the external frame 17 of the rotating device 13.
An electronic device 19a includes all of the required measuring, comparing, amplifying, correcting and shock absorbing elements for good operation, allows an instant comparison between the measurements given by the four receivers 19 and issues a signal which activates the hydraulic cylinder 22, thus controlling the motion of the rotating assembly 10 with reference to the secondary frame 20 and to the container 11, in parallel with the long axis of the container.
The apparatus operates as follows.
Usually, the center of gravity of the container 11 cannot be initially found on the vertical axis traced through the center of the square defined by the plane of the four attaching points 5, 6, 7 and 8, or the four load receivers 19.
Therefore, as soon as the cables are subjected to a tension effort, they are subjected to various loads and the loads measured by the receivers 19 are also different in value. The electronic device detects this difference and controls the hydraulic cylinder so as to cause a longitudinal motion of the rotating device 10 with reference to the container 11, in the appropriate direction. This motion stops as soon as the load difference between the receivers has reached an acceptable value. At this point, the container's center of gravity is located on the vertical axis going through the center of the square defined by cables 1 through 4, and during the lifting operation, the container's axis remains horizontal.
Since the container is stabilized prior to being moved, it never reaches an incorrect position such as a tilted position which could damage the goods that it contains and interfere with the handling operation. The container is stabilized at once regardless of the direction of the container's axis. The container is stabilized through the center of gravity of the container, thus no additional adjustment is required.
Considering this stability and the equal distribution of the loads among the four cables 1 through 4, the four cable portions limited by the frame of the crane and the rotating device 10 subject that frame to a vertical resulting load whose vector passes through the center of the square defined by the plane of the cable attaching points. The frame can then operate in the best conditions. Any incidental torques or loads are thus eliminated, since the resulting load is applied at the center of the plane of the cable system.
Furthermore, the frame 20 is attached to the spreader 12 by means of pins 23 at the one end, and by two cylinders 24, or any other suitable known remote device, at the other end. By maneuvering these devices 24, the spreader 12 may be tilted with reference to the spreader 20, so as to lower and attach it to the container 11 as where the container is resting on a slanted surface.
In conclusion, the advantages are the following:
Even though the square defined by the plane of the cable attaching points onto the fixed element 9 of the rotating device 10 is relatively small, the container 11 can be easily and perfectly stabilized.
The balance is obtained before the container is lifted, and before it reaches an incorrect tilted position.
The cables are not affected by the container's rotation, and the rotating angle of the container is not limited.
The load is equally distributed among the cables, and there is no incidental effort, such as those created by a cambering or a twisting of the frame. The resulting load applied following the lifting of the container is perfectly centered and symmetrical. A greater operational reliability is thus obtained, without having to increase the dimensions of the elements.
With a remote device 24, the container support may be correctly directed so as to attach it to a container resting on a slanted surface.
FIG. 3 illustrates a crane equipped with a handling apparatus built to the specifications of the invention. This crane includes a rotating plate 25 which is mounted on a gantry frame 26, using an orientation crown 27. The plate 25 supports a ballast 28, the mechanisms 29 and a post 30. The boom 31 which is jointed a horizontal pivot of plate 25, may be raised using a reeving 32. The free end of boom 31 includes a horizontal pivot on which is mounted a smaller boom 33. This pivot is connected at the median part of the small boom, and a wire 34 connects the rear part of the small boom 33 with a fixed point in the plate 25. The attaching points of wire 34 are carefully selected, so that the small boom 33, the boom 31, the wire 34 and a line connecting the wire 34 attaching point with the horizontal pivot associated with boom 31, on the plate 25, define the four sides of a pivoted parallelogram.
The main purpose of the small boom 33 is to support the lazy or idler pulleys of the four lifting cables 1, 2, 3 and 4.
The plate 25 includes two lifting hoists respectively equipped with drums 35 and 36 as shown in FIG. 4. Cables 1 and 3 unwind from drum 35, whereas cables 2 and 4 unwind from drum 36. The cables 1, 2, 3 then pass through the lazy or idler pulleys 37 (FIG. 5) which are located on the small boom 33. Thereafter, the cables 1, 2, 3, and 4 are respectively routed through pulleys 38, 39, 40 and 41, before dropping to their respective attaching points on the rotating device 10. The axes of the four pulleys 38 thru 41 are parallel and approximately contained in a single plane. Pulleys 38 and 40 are coaxial and the position of the axes of pulleys 41 and 39 is adjustable. Therefore, the axes of pulleys 39 and 41 are normally kept on either side of the axis which is common to pulleys 38 and 40, but pulleys 39 and 41 may be also moved so as to be coaxial with pulleys 38 and 40 as indicated by the dotted line in FIG. 6. The switch from one position to another is only possible when the cables are unloaded.
At the level of the small boom, and as the pulleys are in their normal position, as shown in the continuous lines in FIG. 6, the four cables, 1 through 4, as seen from the top, are respectively positioned on one of the four corners of a square whose diagonals have a length which is appoximately equal to the width of spreader 12. One of these diagonals is parallel to the boom's axis, whereas the other is perpendicular to the boom's axis when seen from the top. It is therefore understood that the larger the square, the greater the assembly stability during the orientation or displacement operations.
The jointing of the small boom 33 to boom 31 offers a double advantage. First, the boom 31 is subjected to a simple compression only, as the load is lifted, and it still operates in good conditions. Second, thanks to the pivoted parallelogram mounting obtained with the pull-rod or wire 34, the small boom 33 always remains parallel to the plane defined by the axis of pulleys 38 through 41 as the boom's tilt varies, so that the rotating axis of the rotating part 13 of the rotating device 10 always remains vertical.
Even though it is not possible to move the rotating device 10 along the width of the container, in order to compensate a lateral displacement of the center of gravity of the container, it is obvious that such an offsetting is automatically compensated by the mechanism, considering the layout of the four cables. Assuming, for instance, that the center of gravity of the container is located on the same side as cables 2 and 3 on FIG. 1, both cables would then be overloaded, whereas the two other cables 1 and 4 are discharged of a quantity equal to the overload of cables 2 and 3. However, since both of the overloaded cables 2 and 3 are anchored on two different drums which are respectively drums 36 and 35, the load applied to both drums is identical and its value is the one that it would have if the center of gravity were perfectly centered on the width of the container. Therefore, the torque and the rotational speeds of both drums always remain the same.
The crane may easily be modified for use in another application.
After lowering onto the ground the device used for the orientation of the container, the cables may be unfastened at points 5 through 8 so as to allow the mounting of a rotating crossbar as a replacement for the above discussed prehensile apparatus. The new assembly does not affect the relative spacing of the cables.
By mounting pulleys 38 through 41 in line, after displacing pulleys 39 and 41 toward the middle, as indicated by the dotted line on FIG. 6, it is possible to use the device with a two-cable bucket, using the two cables of drum 35 to control the opening of the bucket, and the two cables of drum 36 to close the bucket.
It is also possible to mount a cross-bar equipped with a hook with the device.
In conclusion, the crane thus equipped offers the following advantages, in addition to those offered by the container orientation device.
The vertical axis of the orientation device 10 remains in its initial position, regardless of the boom's orientation.
In case of transverse displacement of the center of gravity of the container, the torque and the rotational speed of both drums remains identical to the value that they would have if the container was perfectly balanced. An overdimensioning of the lifting hoists is thus avoided.
The crane remains a multi-purpose one since its equipment may easily be modified to include a rotating cross-bar, a two-cable bucket or an ordinary lifting cross-bar.
FIG. 7 illustrates a gantry crane equipped with an apparatus built to the specifications of the invention. This gantry includes two posts 42 holding a beam along which a carrier 44 may roll.
This carrier includes two drums 45 and 46 which are perpendicular one to another. Cables 1 and 3 unwind from drum 45, and cables 2 and 4 unwind from drum 46, each one of the cables being able to wind up on an appropriately located and dimensioned zone located at one end of the drum.
When the container 11 is in the raised position, cables 1 through 4 are positioned as indicated at 1h, 2h, 3h, 4h in FIG. 8. The length of the diagonals of the square or of the diamond defined by the four points 1h through 4h is equal or exceeds the width of spreader 12 for the container 11.
Furthermore, the winding direction is such that, as the container is lowered, the cable spacing increases and the cables come to the positions indicated as 1b, 2b, 3b, 4b on FIG. 8, in such a way that the diagonals of the square, or of the diamond defined by the four points 1b through 4b exceed in length the diagonals of the quadrilateral defined by the four points 1h through 4h.
Such a system is therefore comparable to the system previously designed for the crane, the four cables defining from their initial start from the drums, a quadrilateral including a diagonal which is parallel to the long axis of beam 43 of the gantry, and another diagonal which is perpendicular to this axis.
Moreover, this system tends to reinforce the stability during the orientation manoeuvers, as the container is lowered, by increasing the twist rigidity of the four cable assembly, as well as during the back and forth motion operations.
This additional advantage should be added to those offered by the container's orientation device, beside the fact that in the case of a transverse off-setting of the center of gravity of the container, the torque and rotation speed of both drums remain identical to the values that they would have if the container were perfectly balanced.
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A lifting apparatus includes two lifting hoists which are respectively associated with two cables. These cables are lowered in parallel with one another, and are connected to a fixed part of a rotating apparatus. The rotating part of this apparatus moves along longitudinal rails of a secondary frame which is attached to the carrier of the container. The lifting operation may be performed as the container's gravity center reaches the perpendicular axis of the center of a quadilateral defined by four points established by an electronic device which detects the various loads within the lifting cables and is adapted to actuate appropriate hydraulic means to maintain a load differential between the cables below a predetermined value. In this respect, the apparatus balances the containers to be lifted before lifting them.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a horizontally articulated robot, and more particularly to increase of the speed of operation of its horizontal arm and to improvement of the reliability in operation of the same.
2. Prior Art
FIG. 1 shows a conventional industrial robot similar to an industrial robot which has been disclosed by Japanese Patent Application (OPI) No. 211889/1983 (the term "OPI" as used herein means an "unexamined published application"). In FIG. 1, reference numeral 1 designates a base body; 2, a lift shaft provided in the base body 1; 3, a horizontal arm provided on the side of the base body one end portion of which is pivotally mounted on the upper end portion of the base body 1 (hereinafter referred to as "a first horizontal arm 3" when applicable); 4, a first drive unit including an electric motor and a speed reducer, the drive unit being mount on the upper end of the lift shaft 2 to turn the first horizontal arm 3; 5, a horizontal arm provided on the side of work (hereinafter referred to as "a second horizontal arm 5" when applicable), the horizontal arm being pivotally coupled to the outer turning end of the first horizontal arm 3; 6, second drive unit including an electric motor and a speed reducer, the drive unit being provided at the outer turning end of the first horizontal arm 3 to turn the second horizontal arm; 7, an operating hand pivotally coupled to the outer turning end of the second horizontal arm 5; 8, a third drive unit including an electric motor and a speed reducer, the third drive unit being provided at the outer turning end of the second horizontal arm 5 to turn the operating handle 7; 9, a cable inserted into the base body 1 with its one end connected to the first drive unit 4 provided for the first horizontal arm 3; 10, a cable inserted into the base body 1 with its one end connected to the second drive unit 6 provided for the second horizontal arm 5; 11, a cable inserted into the base body 1 with its one end connected to the third drive unit 8 provided for the operating hand 7; and 12, a holder supporting the cables 10 and 11 at the middle.
The conventional industrial robot is constructed as described above. Its hand 7 is positioned by operating the robot as follows: The lift shaft 2 is operated to set the first horizontal arm 3 at a desired level. The first drive unit 4 is energized through the cable 9 to turn the first horizontal arm 3 to be set at a desired position. The second drive unit 6 is energized through the cable 10, to swing the second horizontal arm 5 to be set at a desired position. Similarly, the third drive unit 8 is energized through the cable 11, to turn the hand 7 to cause the latter 7 to take a predetermined posture. With the hand 7 thus positioned, a predetermined operation is carried out. Thereafter, the drive units 4, 6 and 8 are energized again, to perform the next operation.
In the above-described industrial robot, the heavy drive units 4, 6 and 8 are provided at the ends of the first and second horizontal arms 3 and 5, and are energized through the cables 9, 10 and 11. In order to operate the first and second horizontal arms 3 and 5 at high speed or at high acceleration or deceleration speed, it is necessary to increase the output power of the drive units 4, 6 and 8. However, to do so is to increase the weight of the drive unit. Therefore, it is rather difficult for the conventional industrial robot to increase the speed of the horizontal arms. Furthermore, because the robot is operated through the cables 9, 10 and 11, it is essential to prevent the occurrence of troubles due to the breakage or disconnection of the cables.
SUMMARY OF THE INVENTION
An object of this invention is to solve the above-described problems. More specifically, an object of the invention is to provided an industrial robot which can be operated at higher speed and is free from difficulties attributing to the cables connected thereto.
In an industrial robot according to the invention, drive units such as for instance a drive unit for a hand are mounted on the base body thereof, and their operations are transmitted to horizontal arms etc. through respective transmission mechanisms.
In the industrial robot according to the invention, no drive units are provided on the horizontal arms, and therefore the operating sections can be reduced in weight as much. Furthermore, the drive units are mounted on the base body, and the cables can be secured to the stationary section of the robot, thus being prevented from vibration.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view showing a conventional industrial robot;
FIG. 2 is a front view showing one example of an industrial robot a to this invention.
FIG. 3 is an enlarged vertical sectional view showing part III of FIG. 2.
FIG. 4 is an enlarged vertical sectional view showing part IV of FIG. 2.
FIG. 5 is an enlarge vertical sectional view showing part V of FIG. 2.
FIG. 6 is an enlarged side view showing part VI of FIG. 3.
FIG. 7 is a plan view showing part VI of FIG. 3.
FIG. 8 is a sectional view taken along VIII-VIII of FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
One embodiment of this invention will be described with reference to FIGS. 2 through 8, in which components functionally corresponding to those already described with reference to FIG. 1 are designated by the same reference numerals or characters.
In these figures, reference character 2a designates a leg formed by extending the lower end of the cylindrical lift shaft 2 downwardly; 2b, a guide protruded from the leg 2a; 2c, a nut engaged with a ball screw 14c described later; 13, a rail installed vertically in the base body 1 to movably support the guide 2b of the lift shaft 2; 14, a lift drive unit including an electric motor 14a and a speed reducer 14b, the lift drive unit being mounted on the base body 1 and having the ball screw 14c engaged with the nut 2c of the lift shaft 2; and 15, a rotary shaft provided on the side of the base body (hereinafter referred to as "a first rotary shaft 15" when applicable), the rotary shaft being in the form of a cylinder which is inserted into the lift shaft 2 in such a manner that it is rotatably held by the latter. The first horizontal arm 3 which is hollow is secured to the upper end of the first rotary shaft 15, and a driven gear 15b having flange-shaped side plates 15a on its two sides is secured to the lower end of the first rotary shaft 15.
Further in the figures, reference numeral 16 designates a drive unit provided for the first rotary shaft which includes an electric motor 16a and a speed reducer 16b (hereinafter referred to as "a first drive unit 16", when applicable), the first drive unit being mounted on the base body 1; 17, a transmission mechanism which includes a spline transmission shaft 17a made of a bar rectangular in section which is driven by the first drive unit 16; and a driving gear 17b which is slidably mounted on the transmission shaft 17a and which is engaged with the driven gear 15b and is held between the side plates 15a; 18, a transmission shaft provided for the side of work (hereinafter referred to as "a first transmission shaft 18", when applicable), the first transmission shaft 18 including a cylinder which is inserted into the first rotary shaft 15 in such a manner that it is rotatably supported by the latter 15, a driven gear 18b having flange-shaped side plates 18a on its two sides being secured to the lower end of the cylinder; 19, a rotary shaft provided for the side of work (hereinafter referred to as "a second rotary shaft 19", when applicable), the second rotary shaft 19 including a cylinder which is rotatably supported on the outer turning end of the first horizontal arm 3 and has the second horizontal arm 5 which is hollow at the lower end; 20, a belt-laid transmission unit provided for the side of work (hereinafter referred to as "a first belt-laid transmission unit 20", when applicable), the first belt-laid transmission unit 20 comprising a timing belt 20c which is laid over a sprocket 20a secured to the upper end of the first transmission shaft 18 and a sprocket 20b secured to the upper end of the second rotary shaft 19; 21, a drive unit provided for the first transmission shaft (hereinafter referred to as "a second drive unit 21", when applicable), the second drive unit 21 including an electric motor 21a and a speed reducer 21b and being mounted on the base body 1; 22, a transmission mechanism including: a spline transmission shaft 22a made of a bar rectangular in section which is driven by the second drive unit 21, and a driving gear 22b which is slidably mounted on the transmission shaft 22a and which is engaged with the driven gear 18b and is held between the side plates 18a; 23, a transmission shaft provided for the side of the hand (hereinafter referred to as "a second transmission shaft 23" when applicable) which is inserted into the first transmission shaft 18 in such a manner that it is rotatably held by the latter 18, the second transmission shaft 23 having a driven gear 23b at the lower end which has flange-shaped side plates 23a on both sides; and 24, belt-laid transmission unit provided for the side of the hand (hereinafter referred to as "a second belt-laid transmission unit 24", when applicable).
Further in the figures, reference character 24a designates an intermediate transmission shaft of the second belt-laid transmission unit 24 which is inserted into the second rotary shaft 19 in such a manner that it is rotatably supported by the latter 19; 24b, a hand rotating shaft which is rotatably held on the rotary end of the second horizontal arm 5 and has the hand 7 at the lower end; 24c, a timing belt laid over (wound on) a sprocket 24d secured to the upper end of the second transmission shaft 23 and a sprocket 24e secured to the upper end of the intermediate transmission shaft 24a; 24f, a timing belt laid over (wound on) a sprocket 24g secured to the lower end of the intermediate transmission shaft 24a and a sprocket 24h secured to the upper end of the hand rotating shaft 24b; 25, a drive unit provide for the second transmission shaft (hereinafter referred to as "as third drive unit 25", when applicable), the third drive unit 25 including an electric motor 25a and a speed reducer 25b and being mounted on the base body 1; 26, a transmission mechanism including a spline transmission shaft 26a made up of a bar rectangular in section which is driven by the third drive unit 25, and a driving gear 26a which is slidably mounted on the transmission shaft 26a and which is engaged with the driven gear 23b and held between the side plates 23a; and 27, a workpiece held by the hand 7.
In the industrial robot thus constructed, the lift drive unit 14 provided in the base body 1 is operated to drive the lift shaft 2 through the rail 13 until the first horizontal arm 3 is set at a predetermined level. Then the first drive unit 16 provided in the base body 1 is operated to turn the first rotary shaft 15 through the transmission mechanism 17 so that the first horizontal arm 3 is horizontally set at a predetermined position. Under this conditions, the second drive unit 21 provided in the base body 1 is operated to turn the second rotary shaft 19 through the transmission mechanism 22 and the first belt-laid transmission unit 20 so that the second horizontal arm is horizontally set at a predetermined position. Thereafter, the third drive unit 25 provided in the base body 1 is operated to turn the handle rotating shaft 24b with the aid of the transmission mechanism 26 and the second belt-laid transmission unit 24 so that the hand assumes a predetermined posture in a plane.
As is apparent from the above description, the first horizontal arm 3 etc. are driven by the first drive unit 16 etc. provided in the base body 1. Therefore, it is unnecessary to provide drive units at the operating points of each of the horizontal arms etc. with the result that the operating sections can be reduced in weight. Accordingly, the first horizontal arm 3 etc. can be operated readily at higher speed, or at higher acceleration or deceleration speed; that is, it can be operated with short period. Thus, the industrial robot of the invention is high in work efficiency. Furthermore, since the first drive unit 16 etc. are fixedly mounted on the stationary base body 1, the industrial robot of the invention is free form the difficulty that the cables provided therefor are broken being vibrated; that is, the industrial robot of the invention is high in the reliability in operation.
As was described above, in the industrial robot of the invention, the lift shaft is moved vertically by the lift drive unit mounted in the base body, the first horizontal arm is turned through the transmission mechanism and the first rotary shaft by the first drive unit mounted in the base body, the second horizontal arm is turned through the transmission mechanism, the first belt-laid transmission unit and second rotary shaft by the second drive unit provided in the base body, and the hand is turned through the transmission mechanism, second belt-laid transmission unit and hand rotating shaft by the third drive unit mounted in the base body. That is, in the industrial robot of the invention, the operating sections such as the horizontal arms are driven by the drive units mounted on the base body, and therefore they can be reduced in weight as much, and their operations can be achieved readily at higher speed. In other words, the industrial robot of the invention is short in operating period and high in work efficiency. Furthermore, since the drive units are fixedly secured to the stationary base body, the industrial robot is free from the difficulty that the cables connected thereto are broken by being vibrated. Thus, the industrial robot according to the invention is high in the reliability in operation.
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An industrial robot includes a base body, a hand, first and second horizontal arms rotatably coupled to each other, and a lift shaft provided between the base body and the first horizontal arm. The robot also includes drivers provided on the base body for driving the first and second horizontal arms and the hand, respectively, and transmission mechanisms provided in the base body and the first and second horizontal arms for transmitting the output power of the drivers to each of the first and second horizontal arms and the hand.
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FIELD OF THE INVENTION
This invention relates to electrically operated fuel injectors that are used in fuel injection systems of internal combustion engines.
BACKGROUND AND SUMMARY OF THE INVENTION
Typical requirements for a fuel injector require that it be able to withstand numerous hours of corrosive salt spray environment and still display no unsightly visible signs, such as rusting of exposed metal. Past anti-rust measures have included plating the exterior of metal parts of the injector, painting the exterior, or utilizing stainless steel metal.
Plating and painting require careful process control to insure that an even thickness of plating/painting occurs only in the areas desired: surface preparation and cleanliness can be a concern, and uneven covering of the surface results in failure to protect from corrosion. If the plating is applied prior to assembly of subcomponents, contamination of the interior of the injector can result in failed durability or leaking units. Plating or painting after subassembly means subjecting the final calibrated and flowed injector to mishandling or contamination issues which could also result in failed units. Additionally, one area of an injector where it is typically difficult to insure corrosion protection is the mating area between the power group and the valve group.
Although the plating or painting does not involve adding an additional separate "component," this is an extra process, typically requiring expertise in chemical mixing or adhesion. The extra steps of routing, and the associated cost of utilizing specialists can be expensive. Furthermore, continued emphasis on environmental issues involving recycling of old products has made several of the more proven plating solutions unavailable for future use.
Utilizing stainless steel for exterior injector components is another traditional solution for enhancing corrosion protection, but stainless carries drawbacks in that tool wear and material cost can be prohibitive.
The present invention relates to a low cost, snap- or press-on plastic shell component to provide the corrosion protection for the lower end of the fuel injector. Due to the structural embodiment of the concept, the shell can successfully cover varying amounts of exposed steel that tend to be present with any component stack-up situation.
Various features, advantages and the inventive aspects will be seen in the ensuing description and claims which are accompanied by drawings that disclose a presently preferred exemplary embodiment of the invention according to the best mode contemplated at the present time for carrying out the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal cross-sectional view through an exemplary fuel injector embodying principles of the present invention.
FIGS. 2 and 3 are fragmentary longitudinal cross-sectional views illustrating respective modified forms on an enlarged scale from that of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows an exemplary fuel injector 10 comprising a number of parts including a fuel inlet tube 12, an adjustment tube 14, a filter assembly 16, a coil assembly 18, a coil spring 20, an armature 22, a needle valve 24, a non-magnetic shell 26, a valve body shell 28, a valve body 30, a plastic shell 32, a coil assembly housing 34, a non-metallic cover 36, a needle guide member 38, a valve seat member 40, a thin disk orifice member 41, a backup retainer member 42, a small O-ring seal 43, and a large O-ring seal 44.
The needle guide member 38, the valve seat member 40, the thin disk orifice member 41, the backup retainer member 42 and the small O-ring seal 43 form a stack that is disposed at the nozzle end of fuel injector 10, as shown in a number of commonly assigned patents, such as U.S. Pat. No. 5,174,505. Armature 22 and needle valve 24 are joined together to form an armature/needle valve assembly. Coil assembly 18 comprises a plastic bobbin 46 on which an electromagnetic coil 48 is wound. Respective terminations of coil 48 connect to respective terminals 50, 52 that are shaped and, in cooperation with a surround 53 formed as an integral part of cover 36, to form an electrical connector 54 for connecting the fuel injector to an electronic control circuit (not shown) that operates the fuel injector.
Fuel inlet tube 12 is ferromagnetic and comprises a fuel inlet opening 56 at the exposed upper end. A ring 58 that is disposed around the outside of fuel inlet tube 12 just below fuel inlet opening 56 cooperates with an end surface 60 of cover 36 and the intervening O.D. of tube 12 to form a groove for an O-ring seal 61 that is typically used to seal the fuel injector inlet to a cup, or socket, in an associated fuel rail (not shown). The lower O-ring 44 is for providing a fluid-tight seal with a port in an engine induction intake system (not shown) when the fuel injector is installed on an engine. Filter assembly 16 is fitted to the open upper end of adjustment tube 14 to filter any particulate material larger than a certain size from fuel entering through inlet opening 56 before the fuel enters adjustment tube 14.
In the calibrated fuel injector, adjustment tube 14 has been positioned axially to an axial location within fuel inlet tube 12 that compresses spring 20 to a desired bias force that urges the armature/needle valve such that the rounded tip end of needle valve 24 is seated on valve seat member 40 to close the central hole through the valve seat. Preferably, tubes 14 and 12 are crimped together to maintain their relative axial positioning after adjustment calibration has been performed.
After passing through adjustment tube 14, fuel enters a space 62 that is cooperatively defined by confronting ends of inlet tube 12 and armature 22 and that contains spring 20. Armature 22 comprises a passageway 64 that communicates space 62 with a passageway 65 in valve body 30, and guide member 38 contains fuel passage holes 38A. This allows fuel to flow from space 62 through passageways 64, 65 to valve seat member 40. This fuel flow path is indicated by the succession of arrows in FIG. 1.
Non-ferromagnetic shell 26 is telescopically fitted on and joined to the lower end of inlet tube 12, as by a hermetic laser weld. Shell 26 has a tubular neck 66 that telescopes over a tubular neck 68 at the lower end of fuel inlet tube 12. Shell 26 also has a shoulder 69 that extends radially outwardly from neck 66. Shoulder 69 itself has a short circular rim 70 at its outer margin extending axially toward the nozzle end of the injector. Valve body shell 28 is ferromagnetic and is joined in fluid-tight manner to non-ferromagnetic shell 26, preferably also by a hermetic laser weld.
The upper end of valve body 30 fits closely inside the lower end of valve body shell 28 and these two parts are joined together in fluid-tight manner, preferably by laser welding. Armature 22 is guided by the inside wall of valve body 30 for axial reciprocation, specifically on the I.D. of an eyelet 67 that is attached to the upper end of valve body 30. Further axial guidance of the armature/needle valve assembly is provided by a central guide hole in member 38 through which needle valve 24 passes.
In the closed position shown in FIG. 1, a small working gap 72 exists between the annular end face of neck 68 of fuel inlet tube 12 and the confronting annular end face of armature 22. Coil housing 34 and tube 12 are in contact at 74 and constitute a stator structure that is associated with coil assembly 18. Non-ferromagnetic shell 26 assures that when coil 48 is energized, the magnetic flux will follow a path that includes armature 22. Starting at the lower axial end of housing 34, where it is joined with valve body shell 28 by a hermetic laser weld, the magnetic circuit extends through valve body shell 28, valve body 30 and eyelet 67 to armature 22, and from armature 22 across working gap 72 to inlet tube 12, and back to housing 34. When coil 48 is energized, the spring force on armature 22 is overcome and the armature is attracted toward inlet tube 12 reducing working gap 72. This unseats needle valve 24 from seat member 40 open the fuel injector so fuel is now injected from the injector's nozzle. When the coil ceases to be energized, spring 20 pushes the armature/needle valve closed on seat member 40.
Fuel inlet tube 12 is shown to comprise a frustoconical shoulder 78 that divides its O.D. into a larger diameter portion 80 and a smaller diameter portion 82. Bobbin 46 comprises a central through-hole 84 that has a frustoconical shoulder 86 that divides the through-hole into a larger diameter portion 88 and a smaller diameter portion 90. Shoulder 86 has a frustoconical shape complementary to that of shoulder 78.
FIG. 1 shows shoulders 78 and 86 to be axially spaced apart, and it also shows a portion of through-hole 84 and a portion of the O.D. of fuel inlet tube 12 to be mutually axially overlapping. That overlapping portion of through-hole 84 consists of shoulder 86 and a portion of the larger diameter portion 88 of the through-hole immediately above shoulder 86. That overlapping portion of the O.D. of tube 12 consists of shoulder 78 and a portion of the smaller diameter portion 82 of the tube. The significance of this concerns steps in the process of assembling coil assembly 18, fuel inlet tube 12, and shells 26 and 28, as disclosed in the commonly assigned patent application having U.S. Ser. No. 08/292,456 of Bryan C. Hall, "Coil for Small Diameter Welded Fuel Injector", filed on the same date. Reference may be had to that disclosure if the reader desires further details of that invention.
The present invention concerns plastic shell 32 and its relationship to other parts of fuel injector 10. The embodiment illustrated in FIG. 1 shows shell 32 to be of stepped cylindrical shape, comprising a smaller diameter lower axial section 32a, a larger diameter upper axial section 32b, and a step 32c joining sections 32a and 32b. Lower section 32a has circular inside and outside diameters providing a uniform radial wall thickness. So does upper section 32b except for a shallow counterbore 32d at the upper termination of section 32b. The radially inner edge of the counterbore is slightly chamfered. Step 32c has an internal shoulder joining the I.D.'s of the two sections 32a and 32b and a frustoconical tapered external surface joining the O.D.'s of the two sections. The radially inner edge of the internal shoulder of step 32c also has a slight chamfer.
Shell 32 can be assembled onto the fuel injector after the valve group and the power group have been joined together, but before O-ring 44 is placed in its groove around the outside of valve body 30 proximate the nozzle. Shell 32 is coaxially aligned with the nozzle end of the fuel injector and the two are relatively moved together until the shell assumes a position as shown by FIG. 1. The shell is retained in place without any separate fasteners, as by a press-fit or a snap-fit, to one of parts 28 and 30. For example the I.D. of upper section 32b may be pressed onto the O.D. of part 28. After the shell has been properly located, assembly of O-ring 44 onto valve body 30 captures the shell on the fuel injector. The lower termination of the shell is at the upper edge of the groove that receives O-ring 44 while the upper termination is proximate the lower termination of overmold cover 36. The lower termination of cover 36 is shaped with an external groove 36a for complementary fit with the upper termination of shell 32 such that the two mutually axially overlap while their respective O.D.'s are substantially equal so that on the exterior the shell is substantially flush with cover 36 at the overlap. When tolerance stack-ups in the mass production fabrication of such a fuel injector are taken into account, proper axial dimensioning of the two parts 32, 36 at the overlap joint provides superior concealment of the underlying bare metal in comparison to a joint where no such overlap is provided, concurrent with assuring that the shell 32 is properly located for retention purposes. In other words, the overlap joint greatly minimizes, or eliminates entirely, the possibilities that underlying bare metal will been seen through a gap between the two parts 32, 36 and that the two parts will abut prematurely while being assembled together, thereby preventing shell 32 from becoming properly located and retained on the fuel injector.
Shell 32 can be fabricated from conventional plastic materials using conventional manufacturing processes. The plastic is opaque so as to provide the desired concealment of the underlying bare metal, and it may be colored in any particular color for aesthetic or part-identifying purposes. It can be seen that from its overlap joint with overmold cover 36, shell 32 extends axially to cover the circular flange 30f of valve body 30 that forms the upper sidewall of the groove for O-ring ,44, and since the O-ring has a close axial fit in this groove, the shell extends very close to the O-ring, but it does not interfere with the sealing action of the O-ring when the fuel injector is installed on an engine.
FIG. 2 shows an alternate form where shell 32 has a radially inwardly directed flange 32f at its lower end that takes the place of the circular flange 30f on body 30 that otherwise forms the upper sidewall of the groove for O-ring 44. In this embodiment, shell 32 alone forms the upper side of the groove for the O-ring.
FIG. 3 shows another form where O-ring 44 is disposed further away from the end of the nozzle. This necessitates a shortening in the axial dimension of lower section 32a, but the lower termination of the shell has the radially inwardly directed flange 32f that alone forms the upper side of the groove for O-ring 44.
While a presently preferred embodiment of the invention has been illustrated and described, it is to be appreciated that principles of the invention apply to all equivalent constructions and methods that fall within the scope of the following claims.
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A non-metallic cylindrical shell is fitted to the exterior of a metallic valve body portion of a solenoid-operated fuel injector to cover otherwise exposed metal that exists between a lower O-ring seal proximate the nozzle and a non-metallic overmold that covers the solenoid and an adjoining portion of the valve body. The shell and the cover come together at a joint where they mutually axially overlap in such a manner that assures both coverage of the exposed metal and retention of the shell on the valve body for the full tolerance stack-up range of the various parts when assembled.
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PATENTS CITED
The following documents and references are incorporated by reference in their entirety, Gibbs (U.S. Pat. No. D369,939), White (U.S. Pat. No. 7,980,241), Brooks (U.S. Pat. No. D186,487), Wickizer (U.S. Pat. No. D457,029), Soat (U.S. Pat. No. 5,117,806), Maki (U.S. Pat. No. D191,186), Bates Gibbs (U.S. Pat. No. D369,939), Kleefeld (U.S. Pat. No. 5,307,797), Blackshear et al (U.S. Pat. Pub. No. 2009/0211563), Kott, Jr. (U.S. Pat. No. 4,896,651), Czajkoski (U.S. Pat. Nos. 8,151,784 and 7,013,885), Preston (U.S. Pat. No. 4,538,589), Nudo et al (U.S. Pat. No. 4,979,980), Magers (U.S. Pat. No. 6,640,797) and Lewis (U.S. Pat. No. 7,007,687).
FIELD OF THE INVENTION
This invention relates to devices for grilling food over a campfire or other open flame. Furthermore the invention relates to grills which can be used indoors over a fireplace, having a grill stand which makes it possible to position and support the grill member over the burning logs, charcoal or gas.
DESCRIPTION OF THE RELATED ART
Cooking food over an unprepared campfire can be enjoyable, but it is often difficult to find a suitable contrivance to hold the food over the fire. While prepared campfire areas may have built-in grates, the truly wild campfire requires carrying a bulky assembly.
In many locations for outdoor activities, such as parks, beaches or campgrounds, there are permanent grill fixtures or fire pit rings that can be used for cooking or for ambient heat. But even if a built-in grate is provided, it is often unsuitable for a number of reasons; position, height, etc. Built-in grates are often limited in size or only cover part of the open pit, or are constructed such that the heat source and grill assembly are spaced apart a fixed distance. This creates difficulties in cooking different foods having a variety of heating requirements.
What is worst, these outdoor fixtures are frequently damaged or unsanitary because of repeated use without cleaning. In other instances, the outdoor fixtures do not have an assembly for supporting food or the food support is missing or broken. Especially for large groups, there may simply be too little space on the grate to cook everyone's food. Third, it can be difficult and dangerous to place or remove food on a built-in grate, because the fire may unexpectedly flare up and burn the cook's hand.
Thus, there is a need for an adjustable, easy to carry, foldable, campfire grilling device with sufficient space, and with means to easily remove the device from the flame for placing or removing food.
SUMMARY OF THE INVENTION
This section is for the purpose of summarizing some aspects of the present invention and to briefly introduce some preferred embodiments. Simplifications or omissions may be made to avoid obscuring the purpose of the section. Such simplifications or omissions are not intended to limit the scope of the present invention.
In one aspect the invention is about a folding portable grill comprising a center column assembly comprised of two or more vertical members held together by an upper gripper and a lower gripper, yet provide the ability to rotate each said member around said upper and lower grip point, each said vertical member being held by the lower gripper at said member's near end, each said member forming an arch between the distal and near end, with the apex of each arch being located above said upper gripper, wherein the first vertical member has an arch apex that is higher, and a distal end that is farther out from said center column than that of the second vertical member, and said second vertical member's arch apex is also higher and said distal end farther from the center column that any succeeding member, one or more short legs connect to the lower gripper, a grill member, a grill member height adjustment mechanism connected to at least one said vertical member at a position between said upper and lower grippers. In another aspect, the arch and distal portions of the vertical members are pivotable to a storage position where said member portions nest within each other to the storage position, forming an inside volume, the short legs pivot to lie within said inside volume and the grill member is rotated within said inside volume in the storage position. In yet another aspect, the gripper mechanism stops the motion of the member within it by means of a set screw and a butterfly handle on said screw.
Other features and advantages of the present invention will become apparent upon examining the following detailed description of an embodiment thereof, taken in conjunction with the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an isometric view of the Sportsman EZ Grill, according to an illustrative embodiment of the invention.
FIG. 2 shows a front view of the Sportsman EZ Grill, according to an illustrative embodiment of the invention.
FIG. 3 shows a back view of the Sportsman EZ Grill, according to an illustrative embodiment of the invention.
FIG. 4 shows a bottom view of the Sportsman EZ Grill, according to an illustrative embodiment of the invention.
FIG. 5 shows a top view of the Sportsman EZ Grill, according to an illustrative embodiment of the invention.
FIGS. 6-7 show side views of the Sportsman EZ Grill, according to illustrative embodiments of the invention.
The above-described and other features will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
To provide an overall understanding of the invention, certain illustrative embodiments and examples will now be described. However, it will be understood by one of ordinary skill in the art that the same or equivalent functions and sequences may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the disclosure. The compositions, apparatuses, systems and/or methods described herein may be adapted and modified as is appropriate for the application being addressed and that those described herein may be employed in other suitable applications, and that such other additions and modifications will not depart from the scope hereof.
Simplifications or omissions may be made to avoid obscuring the purpose of the section. Such simplifications or omissions are not intended to limit the scope of the present invention. All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinence of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art.
As used in the specification and claims, the singular forms “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a transaction” may include a plurality of transaction unless the context clearly dictates otherwise. As used in the specification and claims, singular names or types referenced include variations within the family of said name unless the context clearly dictates otherwise.
Certain terminology is used in the following description for convenience only and is not limiting. The words “lower,” “upper,” “bottom,” “top,” “front,” “back,” “left,” “right” and “sides” designate directions in the drawings to which reference is made, but are not limiting with respect to the orientation in which the modules or any assembly of them may be used.
It is acknowledged that the term ‘comprise’ may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, the term ‘comprise’ shall have an inclusive meaning—i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term ‘comprised’ or ‘comprising’ is used in relation to one or more steps in a method or process.
The present invention refers to Sportsman EZ Grill FIG. 1 , a portable, collapsible stand and grill assembly. In one embodiment 100 , the grill comprises a frame for supporting one or more grill support surfaces 102 over a fire or other intense heat source. The frame includes an upright center column assembly 104 formed by the pairing of two or more 106 , 108 vertical members, vertically held together by at least two tubular member grippers, an upper gripper 110 and a lower gripper 112 . Each vertical member 106 , 108 combines to form a central axis whose members each form individual arches 124 , 126 that extend to the front of the assembly, so that each respective distal end 114 , 116 of said arches forms an extended support leg 114 , 116 .
The upper tubular gripper 110 is a dual assembly capable of holding two tubular members parallel to each other. The lower tubular gripper 112 has in one embodiment a four element gripper, in order to hold the vertical members 106 , 108 as well as one or more short legs 118 , 120 , so that these short legs may be added to the unit to increase its stability when deployed in a direction opposite from the fire 128 .
The grill 100 also includes a height adjusting mechanism 122 to raise and lower the flat grill member 102 over a campground fire. Said mechanism 122 is located between the upper and lower gripper mechanisms. The grill includes an anti-teetering support system comprised of the combined separation of the front legs or vertical member arch distal ends 114 , 116 , in combination with the location of the one or more short legs 118 , 120 in the rear. These one or more rear legs 118 , 120 are rigidly affixed to the lower gripper 112 .
The front support legs 114 , 116 are rotatable or radially pivotable around the vertical axis of the center. The arches 124 , 126 formed by the forward extension of the vertical member 106 , 108 creates a frame on each side of the grill member 102 , ensuring that the grill member 102 may be placed lower than said arches 124 , 126 , in effect allowing them to not be affected by any fire under the grill member 102 .
In this fashion, the support legs 114 , 116 can be rotated to form the open ended of a Y configuration with said two legs forming the diverging fork portion of the Y, straddling the fire 128 . The rear legs 118 and 120 are similarly placed in the back, and opened to form either a Y (single leg) or H (dual). That radial positioning of the front and rear support legs will support the grill member 102 , and prevent it from tipping over. None of the front support legs 114 , 116 have to be positioned below the grill member 102 itself, so that the fire 128 may burn without charring the legs 114 , 116 yet prevent the grill member 102 from tipping.
The grill member 102 height adjustment or lifting mechanism 122 is capable of maintaining said grill surface 102 level or substantially level throughout a range of height adjustments. The grill member 102 is joinable to a free end of the lifting member 122 , which may have an optional rotatable element, so that the grill member 102 may be brought into/out of the hotter portions of the fire 128 area. Said tubular gripping members 110 , 112 may be fixed by welding or other suitable fixed attachment means, including but not limited to mechanical fasteners such as nuts, bolts and screws, and chemical fasteners such as epoxy.
The attachment of the grill member 102 to the lifting mechanism 122 may be a accomplished by a pivotable connector which preferably includes a pair of pivot points defined by attachment pins, or a set screw along a sleeve, which are preferably threaded nuts attacked by threaded bolts to set against the surface of the vertical members 106 , 108 . The set screw may be a hex, or a butterfly (as shown), or any other suitable torqued device.
The lifting mechanism 122 works in conjunction with a similar set screw or option as described, while maintaining the grill member 102 substantially level. “Substantially level” is intended to indicate a degree of levelness suitable for maintaining grilling items on the grill surface 130 , such that the grilling items do not roll off of the grilling surface 130 . That is, the grill surface 130 can be raised and lowered without angular deflection of the grill surface 130 relative to the center posts 106 , 108 .
Referring to FIGS. 2-7 , we see views that expose the various views of the proposed embodiment of the invention. When looking at the front view 200 , a better appreciation can be had of the level grill member 102 , the upper gripper 110 and the lower gripper 112 . In addition, we see an auxiliary slip member 202 which is in one embodiment a sleeve with a set screw connected to a butterfly 204 to facilitate twisting.
This fixing of the grippers ( 110 , 112 , 202 ) and others to the vertical members 106 , 108 is accomplished in one embodiment by a tubular structure which is adapted fit by a friction fit, however, any chemical or mechanical fastening means can be provided such as the set screws illustrated in the drawings.
The back 300 and top 400 shows that the grill member 102 support includes an aperture into which a portion of the grill member sleeve is inserted and rotatable therein. In one embodiment, the sleeve has a rotation limiting slot there through, so that a rotation-limiting lug may be affixed to the sleeve. The grill member 102 can therefore rotate only a limited distance between the positions where the limiting lug. This rotation-limiting feature prevents rotating the grill member 102 and the food thereon so far that the grill and stand may begin to tip.
Referring now to FIGS. 6-7 we see a side view that illustrates another advantage of the EZ grill. The vertical members are not identical. There is a longer outer 106 member (whose distal end is 116 ), and a shorter member 108 (whose distal end is 114 ). This allows for the folding within each other's arches (the arch of longer member 106 is 124 , and the arch of the shorter member 108 is 126 ) when the unit is folded for storage. When the legs are folded, the members nest together in vertical alignment. The one or more short legs 118 , 120 similarly fold to be within the inside volume 702 .
The grill member 102 may be stored by removal, or it may be loosened and rotated 90 degrees. The grill member 102 links to the vertical support member 106 at a height adjusting mechanism bracket 122 . In one embodiment, an optional support tab 602 may be used to provide additional support to the grill member 102 . In one embodiment, a cotter pin 606 , 608 may be used to keep the vertical support member 106 , 108 within the gripping member 110 , 112 , obviating the need for the set screw arrangement, allowing for the gripping member to rest vertically within the vertical element
The above arrangement would be most suitable if a round cross-section were chosen for the members ( 106 , 108 and others), although other cross sections (octagonal, hexagonal, square, etc.) may be used. Similarly, the assembly components directly exposed to flames or high heat (i.e. 102 , 106 , 108 , 118 , 120 ) may be assembled using ferrous and non-ferrous metals (steel, iron, aluminum, etc.), whereas those members less exposed to flames may be assembled of metal and/or other materials, phenolic materials, all non-ferrous polymers (including amorphous as well as semi-crystalline plastics), ceramics, wood, fiberglass, carbon fiber composites, epoxy composites and others.
CONCLUSION
In concluding the detailed description, it should be noted that it would be obvious to those skilled in the art that many variations and modifications can be made to the preferred embodiment without substantially departing from the principles of the present invention. Also, such variations and modifications are intended to be included herein within the scope of the present invention as set forth in the appended claims. Further, in the claims hereafter, the structures, materials, acts and equivalents of all means or step-plus function elements are intended to include any structure, materials or acts for performing their cited functions.
It should be emphasized that the above-described embodiments of the present invention, particularly any “preferred embodiments” are merely possible examples of the implementations, merely set forth for a clear understanding of the principles of the invention. Any variations and modifications may be made to the above-described embodiments of the invention without departing substantially from the spirit of the principles of the invention. All such modifications and variations are intended to be included herein within the scope of the disclosure and present invention and protected by the following claims.
The present invention has been described in sufficient detail with a certain degree of particularity. The utilities thereof are appreciated by those skilled in the art. It is understood to those skilled in the art that the present disclosure of embodiments has been made by way of examples only and that numerous changes in the arrangement and combination of parts may be resorted without departing from the spirit and scope of the invention as claimed. Accordingly, the scope of the present invention is defined by the appended claims rather than the forgoing description of embodiments.
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The foldable Sportsman EZ grill is described. The Sportsman EZ portable grill has a grill member and a frame. The frame supports the Sportsman EZ grill on a support surface, keeping the front legs away from the fire/heat source, extending outwardly and in an arch from the frame. The support arms have a distal end and a proximal end. The distal end is joined to the support structure which connects to the grill member.
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REFERENCE TO RELATED APPLICATION
This application claims priority from U.S. Provisional Patent Application Ser. No. 60/514,416, filed Oct. 24, 2003, the entire content of which is incorporated herein by reference.
FIELD OF THE INVENTION
This invention pertains to a method and design of automated parachute activation devices that can reliably determine chute release time in low altitude jump scenarios that are typical of military jumps and precision airdrop.
BACKGROUND OF THE INVENTION
Parachuting is a dangerous activity. If the primary parachute fails to deploy either due to malfunction or incapacity of the jumper, the reserve chute must be deployed with enough time to reduce the jumper's downward velocity to safe levels for ground contact. If the primary does not properly deploy and the reserve either does not deploy or does not deploy early enough, the jump will be fatal.
Recreational jumpers generally jump from a high altitude (nominally 5000 ft. above ground) to get the maximum flying time. Automated activations devices (AADs) like those made commercially by Airtec and Astra are used by jumpers in training to safely deploy the reserve chute if the inexperienced jumper goes too low before pulling the main (or if the main is inoperative or the jumper is incapacitated). These conventional AADs detect the jumper's altitude using air pressure above sea level either mechanically or electronically. When the altitude detected is about 1000 ft. above the ground level (these devices must be calibrated at ground level to set how high this is above sea level), these devices activate an automated actuation that deploys the reserve. U.S. Pat. No. 5,222,697 to Allen and U.S. Pat. No. 3,992,999 to Chevrier, et al. show typical actuation systems.
Because there is a relatively long period for safe determination that the main cute has not been deployed in recreational parachuting, current AADs use relatively in accurate pressure sensing to determine the correct time for reserve chute deployment. U.S. Pat. No. 4,858,856 to Cloth and U.S. Pat. No. 4,865,273 to Jones describe a purely mechanical pressure (i.e. altitude) detection systems that activate chute deployment. U.S. Pat. No. 5,825,667 to Van Den Broek describes a device the includes a data processing and an electronic pressure sensor that is used to determine height and an acceleration sensor that is used to compute a redundant height parameter to improve height determination accuracy if the jumper is oriented in the proper way (as detected by a tilt sensor). U.S. Pat. No. 6,378,808 to Smolders also uses an electronic means or measuring altitude as the prime determiner of parachute release time, but does the computation through a complex table driven model computed by an electronic processor. The currently available commercial AADs like the Astra or the Cypress (from Airtec) also uses barometric pressure and pressure changes to determine altitude and rate of decent.
The assumption in all of these prior AAD systems is that pressure change (i.e. altitude based on pressure adjusted for the pressure at ground level) is accurate enough for determination when to deploy the reserve chute (or in the case of an automated chute deployment the main chute). U.S. Pat. No. 5,825,667 acknowledges the accuracy limitations of this approach and incorporates a one axis accelerometer that can be used to improve this height estimate if the tilt sensor indicate that the jumper is in the proper downward facing orientation, but in all of these prior approach there is an assumption that accurate kinematics determination sensing is expensive and therefore should not be used or used in limited ways.
With the advent of low cost position, velocity, and acceleration measurement devices this assumption is no longer valid. While pressure sensing is still an important component to AAD operation, it can now be augment by partial or completely solved jumper kinematic parameter measurement starting at the point of departure from the aircraft down to the point of ground contact. All relevant function and failure mode conditions can be determined and used to trigger reliable reserve (or primary) chute deployment based on both kinematic parameters and pressure-derived altitude measurements.
The addition of direct kinematic measurement to the deployment decision is critical for determination of primary chute failure is low altitude military jumps within approximately the first 5 seconds of the jump and for accurate deployment of the main for precision airdrop.
SUMMARY OF THE INVENTION
This invention is directed to an electronic automatic reserve or primary parachute activation device. The system incorporates partial or complete capture of freefaller or tethered parachute jumper kinematics to rapidly and reliable determine when to automatically activate deployment of the primary or reserve chute.
The preferred embodiments use one or more devices for directly measuring acceleration, velocity and/or position in addition to air pressure change to enable reliable detection of chute deployment conditions earlier than is possible with conventional pressure change activated automated activations devices.
The devices used by the invention may include MEMS accelerometers and/or a MEMS gyroscope.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the basic MEMS-based automated activation device (AAD);
FIG. 2 shows the AAD and an external transmitter which is mounted on the aircraft;
FIG. 3 shows the AAD and an external reflector which is mounted on the aircraft;
FIG. 4 shows the top-level block diagram of an AAD design with added sensors;
FIG. 5 shows how the critical 3 axes of accelerometer (and gyro if they are included) are packaged and mounted on an inertial daughterboard;
FIG. 6 displays the flow chart for the algorithm employed by the Automatic Activation Device;
FIG. 7 shows the Ram-Air/Venturi Effect at Exit effect;
FIG. 8 shows how exit detection can be performed by examining pressure drop over a block (in this case 2 seconds) of time;
FIG. 9 is a scatter plot of the variance of the acceleration at different instants of time after exit, showing the separation between the ordinary jumper and towed jumper;
FIG. 10 illustrates the case of a jumper that has been cut away, showing how the altitude decreases at a constant rate because the jumper is under free fall;
FIG. 11 shows that the pressure signal is constant in case of a retrieved jumper;
FIG. 12 shows an example of this type of plot for a very few data sets; and
FIG. 13 provides examples of common pressure signals for both normal chute deployments and minor malfunction deployments.
DETAILED DESCRIPTION OF THE INVENTION
Military training parachute jumps are often done from 800 ft and can be conducted from even lower. The main chute is deployed by a static line that is attached to the main chute and the aircraft from which the jumper exits. The human body achieves terminal velocity in approximately 5 seconds from exiting the aircraft so each second after this that the main parachute is not properly deployed will take the jumper down approximately 172 feet. Four hundred feet is approximately the last moment when the soldier's reserve can be deployed for a safe landing so there is only 5–7 seconds in which the soldier can decide if this action is warranted. This response time is very challenging, if possible at all.
If the automated opening device is for precision airdrop, i.e. operates the main chute, each second delay in opening will result in between 130 and 260 ft error in the final payload touchdown point.
The system implemented by the inventors ( FIG. 1 shows the basic MEMS-based AAD) couples low cost micromechanical (MEMS) accelerometers and optionally MEMS gyroscopes to allow computation of partially or completely specified jumper kinematics (with three orthogonally oriented accelerometers we assume that the jumper is not tumbling and compute a positions and velocity solution by integrating accelerometer outputs and when three orthogonally oriented gyroscopes are added we compute positions, orientation, and rates of change of both of these). Adding these orientation-free kinematics sensors does not add undue cost because MEMS devices, such as those used in commercial airbag deployment, are inexpensive. Jumper velocity [Vj x , Vj y , Vj z ] and position [Pj x ,Pj y ,Pj z ] can be computed by numerically evaluating:
[ Vj x , Vj y , Vj z ]=[Va x , Va y , Va z ]+ƒ[Aj x ,Aj y ,Aj z ]dt (1)
[ Pj x ,Pj y ,Pj z ]=[Pa x , Pa y , Pa z ]+ƒ[Vj x , Vj y , Vj z ]dt (2)
Where: [Aj x ,Aj y ,Aj z ] is the measured jumper's accelerations, [Va x , Va y , Va z ] and [Pa x , Pa y , Pa z ] are the aircraft's velocity and position, and [Vj x ,Vj y ,Vj z ] and [Pj x ,Pj y ,Pj z ] are the jumper's velocity and position.
In alternative implementations, the MEMS accelerometer/gyroscope sensors can be replaced by other range and rate detection sensors. For instance if an FM tone is transmitted from the jumper to a reflector on the aircraft and back to the jumper or from the aircraft to the jumper, the tone frequency detected by the jumper will be frequency shifted by the difference in relative velocity between the jumper and the aircraft ( FIG. 2 shows the AAD and an external transmitter which is mounted on the aircraft). This Doppler shift can be detected using FM demodulation. In this case acceleration is determined as:
Aj=dV/dt (3)
Jumper velocity as:
Vj=V+Va (4)
And position is detected as:
Pj=Pa+ ƒ( V+Va ) dt, (5)
Where: Aj, Vj, and Pj are the jumper's acceleration, velocity and position, Pa and Va are the plane's position and velocity, and V is the relative velocity measurement by the FM detector.
If a pulse is transmitted from the jumper to the aircraft and back, the time of flight can be measured against a precision crystal clock to accuracies of several centimeters ( FIG. 3 shows the AAD and an external reflector which is mounted on the aircraft). This is range measurement determines the relative position of the jumper to the aircraft. In this case jumper position is determined as:
Pj=P+Pa (6)
Jumper velocity as:
Vj=dPj/dt (7)
And acceleration as:
Aj=dVj/dt (8)
Where: Aj, Vj, and Pj are the jumper's acceleration, velocity and position, Pa is the plane's position and velocity, and P is the relative distance from the plane to the jumper measured by ranging.
The preferred embodiment described further uses MEMS devices because they directly measure kinematics parameters (rather that indirectly through FM demodulation or time of flight). This makes calibration simpler for the MEMS systems and also has the added benefit of complete passivity (i.e. there are no detectable emissions from the sensor system—both FM and time of flight systems emit RF signatures to several times the range between the aircraft and where the chute deployment decision must be made—in a military applications this presents a detectable signal from the plane at ground level that can be used for detection and weapons targeting).
Three (or six) MEMS inertial devices are preferred because they measure all of the true components of body motion, whereas, FM demodulation and RF ranging only measure rate or range along the propagation direction of the RF emissions. This means that errors will be made in estimating jumper downward velocity based on the changing geometry between the emitting antenna and the jumper (i.e. the aircraft and the jumper). Furthermore, RF signals will degrade in quality based both on range from the aircraft and orientation of the jumper relative to the aircraft (i.e. if the jumper is tumbling, signal strength will vary due to the changing orientation of the receive and transmit antennae).
Circuit Design
FIG. 4 shows the top-level block diagram of an AAD design with added sensors: 3 axis magnetometer (sensing direction from the Earth's magnetic field), 3 axis gyro and 3 axis accelerometer (shown as the 3 axis Accelerometer and Gyroscope IMU Cube), a redundant GPS receiver (for determining position by GPS satellite signal), and pressure sensors (Analog barometric pressure, Digital pressure, and Differential pressure or airspeed). This design can accomplish the data collection for both AAD and for recording full jumper trajectory during freefall and later decent after the chute is deployed to touchdown on the ground. Data collected in recording mode is entered into the flash memory for permanent storage until it is read out at an analysis station. This is done through either the USB interface or the RF TXCVR.
The GPS, magnetometer set, 3 gyroscope axes, differential pressure sensor, redundant barometric pressure sensor (digital or analog), and the record flash memory and analysis PC communications (USB and RF TXCVR) are not necessary for the AAD but are included to implement a jumper decent trajectory recording function as well. Not shown are I/O lines from the DSP to the arming switch and the AAD actuation device (normally a pyrotechnic that pulls the disconnect pin or bolt that releases the main or reserve chute).
FIG. 5 shows how the critical 3 axes of accelerometer (and gyro if they are included) are packaged and mounted on the Inertial Daughterboard. This very compacted three dimensional packaging allows for (a) good temperature control (MEMS devices are highly temperature change sensitive), (b) rigid mounting, and (c) very compact form factor.
Detailed Algorithm Design
The heart of the AAD design is it software/firmware. In recording mode the device is powered and armed by pressing the user button. The DSP start up its program, initializes the attached sensors (see FIG. 4 ) and begins capturing data at the preprogrammed rate for each sensor (typically 100 Hz–10 Hz for magnetometer and GPS). Each sensor data item is inserted into the Flash memory buffer. Recording continues until the memory is full or the device is connected to an analysis station (a personal computer). In the recording mode the AAD/recorder can only be used one time before it is connected to the analysis station and has its data downloaded. The download process erases the flash memory and re-initializes the AAD/recorder for reuse when the current recorded data set is completely transferred into the analysis station.
In AAD mode, the device is powered and armed by pressing the user button. The DSP also start up its program, initializes the attached sensors (which can be subsetted to 3 axis accelerometer and a single pressure sensor), and begins data capture at 100 Hz. Each sensor data item may be recorded for later analysis (as in recording mode), but is also analyzed to detect malfunctions in the decent process. The principal goal of this processing is to determine when and if to release the actuator that deploy a main pr reserve parachute within nominally the first 5–8 seconds of the decent.
The phases of military jumping is as follows with the annotated failure modes and remediation.
TABLE 1 Failure modes and remediation Phase Failure Remediation Pre-jump Accidental chute deployment - No aircraft exit is detected - no not pulled out of aircraft action Pre-jump Accidental chute deployment - Jumper is most likely injured. pulled out of aircraft His exit is detected with change in pressure environment and due to acceleration of the rapid exit. If descent rate is nominal, no action. If main does not deploy properly so that descent is too fast, Action: deploy reserve. At exit from aircraft Jumper Tumbles The jumper should not tumble because this may cause main chute entanglement. However, often this happens to jumpers, especially during training. Action: record jumper trajectory and report tumbling during exit to training supervisor. At end of static line (main chute May be tangled in static line - Detect towed condition by high deployment point) main does not deploy and jumper deceleration. Take no initial is towed - this is called tow action. Wait for detection of jumper failure possible cutting of towline - descent that was halted begins. If this is detected Action: deploy reserve. Otherwise detect that jumper has been retrieved by monitoring the ambient pressure. In this case, do not deploy reserve. At end of static line (main chute Static line pulls and detaches, Descent rate to fast. Action: deployment point) main does not deploy deploy reserve. At end of static line (main chute Static line pulls and detaches, Descent rate to fast. Action: deployment point) main deploys but only partially deploy reserve. opens due to entanglement or other failure Jumper tumbles Main deploys but is partially If tumbling causes entanglement below jumper due to tumbling in main this is detected as a partial chute failure by detecting increased descent rate compared to nominal. Action: deploy reserve. Jumper tumbles Main deploys and jumper rights No action - jumper's deceleration is close to nominal
As indicated above the critical actions require that the AAD system:
(1) Reliably detect exit from the aircraft (Exit Detection Algorithm) (2) Detect tow jumper case where the line fully extended, chute is not deployed, and the jumper is being dragged (Towed Jumper Algorithm)
(3) Detect main failure or partial deployment which is from too rapid of a descent before chute is fully deployed (Severe Malfunction Detection Algorithm and Minor Malfunction Detection Algorithm)
(4) Detect proper chute deployment so as to disable any further function accept recording (None of the above) (5) Record the descent trajectory data for after jump review with training supervisors.
FIG. 6 displays the flow chart for the algorithm employed by the Automatic Activation Device. This algorithm can be broken down into four separate sections. These sections are . . .
1. Exit Detection Algorithm 2. Towed Jumper Algorithm 3. Severe Malfunction Detection Algorithm 4. Minor Malfunction Detection Algorithm
This list is chronological. First, the AAD determines when the jumper exits the aircraft. Then the AAD determines if the jumper is being towed. Only then does the AAD determine if a malfunction has occurred. Exit is detected first because a reference point in time is needed. All jumps begin with an exit from the aircraft. The towed jumper algorithm is next because deploying the reserve while a jumper is towed can be fatal. Therefore, the AAD must determine that the jumper is not towed before allowing malfunction detection to begin. The following sections describe each part of the AAD algorithm in detail.
The Exit Detection Algorithm
The first thing the algorithm does is to detect the jumper's exit by monitoring the pressure signal and looking for a large and distinct change. A high frequency spike is caused by the exposure of the pressure sensor's orifice to the turbulence surrounding the aircraft as well as the ram air and Venturi effects caused by entering the high velocity column of air directly outside of the aircraft. The Venturi effect describes the result of fast moving air over the top of the sensor which creates a low-pressure area within the orifice producing a pressure measurement lower than ambient. The ram air effect has the opposite result and occurs when the orifice is facing directly into the wind vector. This creates a local high-pressure area immediately within the orifice, which results in a pressure measurement higher than ambient. This effect, Ram-Air/Venturi Effect at Exit, is illustrated in FIG. 7 .
A simple FIR filter is used to detect this spike. The filter has a length of 64 and is a purely causal filter, hence has a theoretical delay of zero. The Exit Detection Filter (EDF) coefficients are:
[
111
…1
16
bins
000
…0
46
bins
-
8
-
8
2
bins
]
EDF
coefficients
(
9
)
This filter has been verified by generating its output for all jumps performed and showing that a threshold can be set that will properly identify all exit times without any false detections.
To counteract the cases where large pressure variations in the aircraft could trigger a false exit, the pressure signal is monitored for 0.70 s after the filter detects a spike. During this 0.7 seconds, a consistent increase in pressure (drop in altitude) verifies a true exit. Hence for all practical purposes the exit detection algorithm has a delay of 0.86 s. Since there is no action that needs to be taken within 0.86 s, the delay is acceptable and there is no cumulative effect of this delay in the further branches of the algorithm.
To handled cases where the Venturi effect is smaller, for instance when exiting a very slow moving platform like a helicopter at or near hover, pressure sensor changes are compared over a longer time interval so that the effect has time to develop as a result of the jumper's initial period of freefall descent. FIG. 8 shows how exit detection can be performed by examining pressure drop over a block (in this case 2 seconds) of time. The drop in pressure is proportional to a corresponding descent rate not possible while the jumper is still in the aircraft.
The Towed Jumper Algorithm
A towed jumper will experience a large variation in his/her total acceleration because of the varying forces exerted by the static line. A jumper who is not towed very little variation in total acceleration.
The above hypothesis has been verified from the accelerometer measurements obtained from field jumps. FIG. 9 is a scatter plot of the variance of the acceleration at different instants of time after exit, showing the separation between the ordinary jumper and towed jumper.
Based on a combination of maximum separation in the scatter and the need to make an early decision, the ideal time to detect a towed jumper was decided to be at t=1.0 s from exit which is between the average time for deployment bag separation and the average time for apex break away. See Table 1.
TABLE 1
Time Elapse for Key Points in T-10 Trajectory
Trajectory Event
Average Time From Exit
Deployment Bag Separated
0.8 sec
Apex Breakaway
1.4 sec
Full Inflation
2.8 sec
First vertical
4.1 sec
Second Vertical
6.5 sec
The threshold for making the decision is 3.9046 ft 4 /s 2 . After detecting a towed jumper, the jumper is monitored for the possibilities of the towed jumper being cut-off or retrieved. This is important because deployment of a reserve when the jumper is retrieved should be avoided. Additionally, if the jumper is cut away, the AAD should deploy the reserve.
Detecting a Retrieved Towed Jumper and Cut-Off Towed Jumper:
While the jumper is being towed there is a very high variance in the pressure signal (altitude derived from pressure signal) because of the ram air and Venturi effects. This fact is used to observe the variance of the pressure signal. A significant drop in the variance indicates that the towed jumper has either been cut away or retrieved.
In the case of a jumper that has been cut away, the altitude decreases at a constant rate because the jumper is under free fall. This can be observed in FIG. 10 and is utilized to detect a cut away towed jumper and deploy the reserve.
In the case of the towed jumper being retrieved, the constant drop in altitude cannot be observed. In FIG. 11 shows that the pressure signal is constant in case of a retrieved jumper.
The Severe Malfunction Detection Algorithm
Once it is certain that the jumper is not towed, it is safe for the malfunction detection algorithm to proceed. It is advantageous to begin with the severe malfunctions (total malfunction and 5 percent partial malfunction). This is because when there is no canopy above the jumper or it is just a streamer, there is very little time between exit and impact. Therefore, the sooner severe malfunctions can be detected, the better chance for survival of the jumper.
The Severe Malfunction Detection Algorithm was developed by calibrating the accelerometer sensor values. This yielded acceleration versus time in three orthogonal axes. (For simplicity we will call these axes X AAD , Y AAD , and Z AAD .) These axes represent the frame of reference of the AAD itself.
Once the acceleration forces have been calibrated, an overall force is computed by performing a magnitude calculation and subtracting one G. One G is subtracted from the magnitude as it is known that the Earth's gravitational filed always exerts one G upon the AAD. (An AAD sitting on the shelf is experiencing one G, but it is not accelerating.)
TotalAcceleration=(√{square root over (([ A X AOD ] 2 )}+[ A Y AOD ] 2 +A[ Z AOD ] 2 ))−1.0 (10)
This total acceleration is then integrated to yield total velocity.
TotalVelocity [ n ] ∑ i = 0 n TotalAcceleration [ i ] ( 11 )
Analysis and experience has shown that this total velocity metric is key in the deciding whether or not a malfunction has occurred.
In order to develop and refine the algorithm, data was collected. This data included normal and malfunction scenarios. The malfunction scenarios were divided up into four categories. They are Total Malfunction, 5 percent Partial, 30 percent Partial, and Towed Jumper. A Total Malfunction occurs when no chute opens whatsoever. A 5 percent Partial occurs when the parachute only opens to 5 percent of its normal diameter. This malfunction is also referred to as a streamer. A 30 percent Partial occurs when the parachute only opens to 30 percent of its normal diameter. 30 percent of normal diameter is defined as the threshold between a malfunctioning chute and a normal deployment. A towed jumper malfunction occurs when the jumper is hung up on the static line.
In order to differentiate between malfunctions and non-malfunctions, the total velocity data was analyzed. Each data set has a total velocity signature versus time and an associated malfunction. Each total velocity signature was plotted against time and is type coded. FIG. 12 shows an example of this type of plot for a very few data sets.
At each point in time, starting with exit time (0 s in FIG. 11 ), a probability distribution function (PDF) of total velocity for each malfunction type is calculated. Therefore, at every index of time after exit, a PDF is created for all types of jumps. These PDFs are then analyzed in the total velocity dimension to evaluate the separation between PDFs. In FIG. 10 , for instance, when time after exit is between zero and one second, separation among the malfunction jumps is unsatisfactory. When time after exit reaches four seconds, however, there is very good separation between the malfunction drops and the non-malfunction drops.
Once all of the PDFs have been created at every index of time after exit, the time which yields the best separation between malfunction and non-malfunction jumps is chosen as the decision time. The point in between the PDFs of the malfunctions and the PDFs of the non-malfunctions that produce the least amount of overlap become the total velocity threshold.
The Minor Malfunction Detection Algorithm
Once the overall algorithm has either detected a severe malfunction or determined that there has not been a severe malfunction, a final algorithm can be carried out to detect minor malfunctions. Minor malfunctions are classified as the 30 percent partial malfunctions. When a parachute only opens to 30 percent of its diameter, it is still stable. The only difference is that the chute does not decelerate the jumper enough. During a minor malfunction, the jumper is falling at a rate that is not safe.
To detect a minor malfunction, this portion of the algorithm uses the pressure sensor. During a minor malfunction, the signal from a pressure sensor is stable. The pressure signal is differentiated to determine how much the pressure is changing over time. Since pressure is directly related to altitude this is the same as computing the rate of change in altitude or the rate of descent. This portion of the algorithm monitors the rate of descent. If it is ever too high, then the algorithm initiates the reserve deployment. This check is made continuously until the jumper has landed safely on the ground.
Examples of common pressure signals for both normal chute deployments and minor malfunction deployments are shown in FIG. 13 . It is clear that the minor malfunction plots show a faster descent than the non-malfunction plots
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An electronic automatic reserve or primary parachute activation device incorporates partial or complete capture of freefaller or tethered parachute jumper kinematics to rapidly and reliable determine when to automatically activate deployment of the primary or reserve chute. This device uses means for directly measuring acceleration, velocity and/or position in addition to air pressure change to enable reliable detection of chute deployment conditions earlier than is possible with conventional pressure change activated automated activations devices. This is important when the activation decision must be made within 5–10 seconds of the initiation of the jump as is the case for military low altitude parachuting.
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FIELD OF THE INVENTION
This invention relates to storage compartments, and particularly relates to storage compartments designed to utilize space within an automobile door or the like moving vehicle, and more particularly to a door mounted storage device capable of movement in response to a door window position.
BACKGROUND OF THE INVENTION
It is customary in many cases for a middle arm rest of the front seat of a vehicle to be used as a storage compartment or provided with areas where articles may be placed or deposited. In particular, cup and can holders, ashtrays or oddments trays are often fastened to the front end of the arm rest. When not in use, they may be inserted into the arm rest to eliminate risks of injury and avoid clutter. Door panels are often provided with small pockets for holding maps or small items. Door armrests may be provided with a hinged upper portion to facilitate storage of small oddments or maps.
In airplanes all handbags and pocketbooks must be stored either in the overhead compartment or under the forward seat. Such precautions are necessary because they can become missiles in the event of severe turbulence or a crash. In airplanes, the greatest risk is during take-off and landing but in car travel the risk of accident is continuous. The need to store pocketbooks is therefore continuous.
However, within the limited interior space of most vehicles, especially those constructed without a middle armrest, typically there are not provisions for storage of larger articles such as a women's handbag. Handbags are often placed on top of a seat within the passenger compartment or they are dropped into the floor area for storage during driving. These unsecured articles may create a dangerous condition in the event of an accident, wherein they may act as projectiles flying though the air.
Women have long sought for a place to store their handbags to be conveniently available when needed. There are inumerable examples of working women and stay at home moms taking their children to school or elsewhere and passing a drive-in to pick up coffee, a soda, dinner or a snack. The handbag is often in the back seat and a hassle ensues to retrieve it. The same is true when passing a toll booth. No storage area exists that is specifically constructed to accommodate a handbag.
In addition, theft of personal articles from automobiles is an ever-growing problem. The use of vehicle alarms, while of benefit in reducing the number of actual vehicle thefts, is of little value in reducing the number of so-called “smash & grab” robberies. These robberies are events of opportunity, often precipitated by the perpetrator's ability to view the object of their desire, at which point they can quickly break in, grab the merchandise, and quickly get away, before the tripping of an alarm device becomes a matter of any consequence.
What is lacking in the art is a device for securely and inconspicuously storing valuable items, such as a woman's handbag, within an automobile door cavity so as to provide convenience, increase safety and reduce the likelihood of theft. The storage space should provide some degree of side impact shock absorption and the storage space should provide some dis-incentive to break into a car for valuables.
DESCRIPTION OF THE PRIOR ART
Various attempts have been made in the prior art to develop means for storing personal items in a manner to provide personal convenience and to keep the stored articles out of view.
For example, Barker, U.S. Pat. No. 4,023,873, discloses a combination armrest, trash receptacle, ashtray and cash container formed from an elongated rectangular member having a horizontal top forming an arm rest. The horizontal section is provided with a hinge rod and the horizontal member having three separate doors hinged to the rod so that the three compartments therein can be separately opened.
Laesch, U.S. Pat. No. 5,613,723, discloses a storage armrest mounted on a vehicle door. The storage armrest includes a door hingedly mounted thereon, with a hold-open device integrally molded on the door and in the storage compartment. The hold-open device includes a substantially one-fourth circle cam molded on an inner surface of the door, and a flex finger molded on an upper surface of the storage compartment. The flex finger serves to hold the door open until manually forced downwardly, thereby bending the flex finger while the cam moves therepast to allow the door to be closed.
Ramanujam, U.S. Pat. No. 5,967,594, discloses a vehicle door structure having an armrest which is retractable such that it projects into the vehicle when the door is closed and is retracted against the door when the door is open.
Johnson et al, U.S. Pat. No. 6,161,896, disclose a storage system for an automotive vehicle which is preferably deployed underneath the rear seat structure, for example, below the seat bottom structure. The storage system can include any number and combination of selectively operable sliding trays, pivoting trays, collapsible trays, pivoting lids, storage bins, and track systems.
Radcliffe, U.S. Pat. No. 4,832,241, discloses a vehicle portable-office organizer designed to be detachably mounted to the passenger seat of a vehicle.
Various patents are directed to center consoles located between the driver and passenger seats. These patents include U.S. Pat. Nos. 6,419,314, 6,264,261, 5,076,641, 6,135,529, 6,033,015, 4,417,764, and 6,497,441.
Scheerhorn, U.S. Pat. No. 6,419,314, discloses a center console armrest storage compartment which includes a hinged cover assembly including a base hinged to the storage compartment and a cover slidably mounted to the base by a slide assembly. The slide assembly, in one embodiment, includes a U-shaped rod which is secured to the base and a pair of sleeves mounted to the cover with a polymeric slide material extending between the rod and sleeves to allow the cover to slide forwardly and aft with respect to the base. In a preferred embodiment, the base, when uncovered by moving the cover forwardly, includes a storage tray, cup holder or other accessory, which is stacked above the storage compartment.
De Angelis et al., U.S. Pat. No. 6,135,529, disclose a multi-position sliding center console for a vehicle and a guide member for mounting the console to the vehicle. The center console is of the type including at least one storage compartment and an associated lid. The guide member defines a reciprocal path from a first end of the guide to a second end of the guide. The first end of the guide is adjacent a set of front passenger seats and the second end of the guide is adjacent a set of rear passenger seats. A carriage is operatively coupled between the console and the guide member for slidably moving the console on the guide member along the reciprocal path between the front and rear passenger seats.
Krafcik, U.S. Pat. No. 6,264,261, discloses a vehicle console which is adapted to store a child safety seat and is further adapted to operatively and movably support and position the child safety seat within the vehicle. The console includes a pair of child seat attachment members which removably connect the child safety seat to the console, and a lip or flange portion which allows the child safety seat to be securely supported by the console when deployed within the vehicle.
Lindberg, U.S. Pat. No. 5,076,641, discloses a center console vehicle armrest which includes a storage compartment formed therein and having a cover which opens in two directions to increase accessibility to the inside of the compartment. A preferred embodiment includes an intermediate ring pivotally coupled to the cover and to the compartment and latches for allowing the cover and ring to pivot open in one direction and the cover to pivot open in another direction
Husted, U.S. Pat. No. 6,033,015, discloses an armrest assembly comprising a bin defining a storage compartment and a cover hinged to the bin for movement between open and closed positions. A shaft rotatably supports the cover on the bin for pivotal movement of the cover relative to the bin. A helical torsion spring is coiled about the shaft and has one end reacting with the bin and the other end reacting with the cover for continuously urging the cover to the open position. A detent, having at least one caming surface, is disposed on the shaft for engaging the bin and is rotatable with the cover for retaining the cover in at least one detent position. The detent is located between the bin and the spring. Accordingly, the spring continuously biases the detent axially against the bin and also continuously biases the cover to the open position.
Bargiel, U.S. Pat. No. 6,508,508, discloses an armrest storage unit comprising a compartmentalized pullout armrest assembly which includes a cover, an armrest storage compartment, and a seat cushion with an understorage compartment. The armrest storage compartment includes maneuverable dividers for changing the storage compartment as desired, a removable coin holder and a power supply. The armrest assembly can be positioned to provide a third seat.
Marcus et al., U.S. Pat. No. 4,417,764, disclose an armrest for a vehicle which integrally includes a drawer having a holder for different types and sizes of beverage containers. The drawer is releasably secured within a compartment, integral with the armrest, and includes a floor having an aperture therethrough for receiving generally cylindrical objects such as cups. U-shaped legs are pivotally mounted under the floor to be positioned below the apertures to support the bottom of a cylindrical container. In the preferred embodiment the compartment further includes a slide with recesses for holding a writing instrument and writing media such that the slide forms a support for writing on the media.
Mahmood et al., U.S. Pat. No. 6,497,441, disclose a multipurpose console for use in a vehicle having a support structure having an internal compartment, a latching mechanism being fixedly secured to a lower surface of the support structure and providing a means for releasably engaging a mounting member of the vehicle. The internal compartment has a lid pivotally secured to an upper portion of the support structure and moves between a first position and a second position. The lid covers the internal compartment when the lid is in the first position and the lid has an upper portion and a lower portion. The upper portion is pivotally secured to the lower portion for movement between the first position and the second position. The upper portion and the lower portion define a surface area for changing a child's diaper when the upper portion is in the second position. The internal compartment provides a plurality of storage areas for products necessary to facilitate the changing of the child's diaper. The multipurpose console also includes an electronic entertainment device.
Prior art patents which are directed to door-mounted storage armrests (U.S. Pat. Nos. 3,104,131, 4,023,873 and 5,613,723) do not disclose storage compartments which extend into the vehicle door cavity to provide a deeper storage area. The instant invention satisfies a long-felt need for adequate and accessible vehicle storage by providing a device which is designed to be placed in a recessed position within the vehicle door cavity, thereby taking advantage of the increased depth thus obtained.
SUMMARY OF THE INVENTION
The present invention provides means for expanding the usable interior space of a vehicle, either as original equipment installed by the manufacturer or as an after-market modification, so as to provide a means for providing storage capacity for a vehicle which is characterized by ease of use and the ability to provide secure storage for women's handbags.
To achieve this result, the instant invention utilizes the interior space of a vehicle door. The invention utilizes the space within the vehicle door and still accommodates the opening of the car window. This is accomplished by having a box within a box, the inner box being slightly smaller, which pushes forward one half inch to accommodate the window as it comes down upon opening. There are small covered springs attached to the outer frame, at each corner of the outer box, which springs are attached to the inner box, keeping the two boxes aligned and providing some energy to push the inner box back into the door cavity as the window is raised. The exterior covering of the outer box is a reinforced pleated vinyl or leather in conformity with the cars interior. The material and pleats provide for expansion as well as the side flaps.
The storage compartment has, opposite sides, a top and a bottom for connecting peripheral portions of a front and a back panel member so that the panel members face each other to form front and back inner boundaries of an interior portion of the storage compartment, a interior portion which is preferably accessible from the top side or front side of the storage compartment. The interior portion of the storage compartment may also include padding to further protect the stored items.
The construction of the storage compartment facilitates storage of many different sizes and types of articles, e.g. a make-up bag, handbag, pocket book, writing instruments, smoker's requisites, a headset or the like. In an advantageous development of the invention, the storage compartment is provided with a closable covering means illustrated generally as a flap, roller blind or lid. The covering means is advantageously capable of pivoting about an axis at the edge of the recess, or winding around an axis in combination with a spring retraction mechanism, wherein the point at which the axis is provided is preferably at or along the edge of the storage area in which is situated for placement of articles within the storage compartment. In addition, the covering means is preferably latchable such that articles may be secured so that they remain in position, particularly in the event of an accident. In this manner, the contents of the storage compartment are fixed in position and, particularly in the event of an accident, the risk of injury from flying articles or as a result of impact with hard inner surfaces of the storage compartment is avoided. Thus, the covering means in the present invention is a device for safeguarding the contents of the storage compartment.
It is also conceivable to design the storage compartment as a shock absorber which may be used to cushion side impacts of the vehicle. In this embodiment the outside of the roller blind or lid may be provided with a covering and, optionally, a thin layer of padding. The visual appearance of the storage compartment is also enhanced in this manner.
Accordingly, it is a primary objective of the instant invention to provide enhanced vehicle storage capacity by utilizing the heretofore unused space within a vehicle's door by way of provision of a dynamic receptacle for accommodating bulky items, such as women's handbags therein.
It is a further objective of the instant invention to provide enhanced and coverable storage capacity which places articles within the vehicle out of view, so as to reduce the incidence of theft.
It is yet another objective of the instant invention to provide in-door storage the volume of which is adjustable as a function of window position.
Still another objective of the instant invention is to provide an additional, easily accessible storage compartment useful for women's handbags.
Still yet another objective of the instant invention is to provide a storage compartment utilizing space within the vehicle door cavity while the functionality of the window and other equipment contained within the door are retained.
Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a perspective view of a preferred embodiment of the instant invention illustrated secured within a vehicle door;
FIG. 2 is a partially exploded view of the preferred embodiment illustrated in FIG. 1 ;
FIG. 3 is an exploded view of the preferred embodiment of the instant invention;
FIG. 4 is section view along lines 1 - 1 of FIG. 1 illustrating the relative motion of the front and back panels with respect to downward motion of the vehicle window;
FIG. 5A is a perspective view of an alternative embodiment of the instant invention illustrated secured within a vehicle door;
FIG. 5B is a partial front view of the embodiment shown in FIG. 5A illustrated with the front panel removed;
FIG. 5C is a partial perspective view of the embodiment shown in FIG. 5A ;
FIG. 6 is a partially exploded view of the embodiment illustrated in FIG. 5 ;
FIG. 7 is section view along lines 2 - 2 of FIG. 5 illustrating the relative motion of the front and back panels with respect to downward motion of the vehicle window;
FIG. 8 is a perspective view of an alternative embodiment of the instant invention;
FIG. 9 is a perspective view of an alternative embodiment of the instant invention;
FIG. 10 is a perspective view of an alternative embodiment of the instant invention;
FIG. 11 is a perspective view of an alternative embodiment of the instant invention.
DETAILED DESCRIPTION OF THE INVENTION
The instant invention provides a storage compartment adapted for insertion within and upon an interior panel of a vehicle door. With reference to FIGS. 1 and 2 , a storage compartment 100 , having a front panel member 10 , a back panel member 12 and a center panel member 14 is provided. The storage compartment 100 is constructed and arranged for mechanical engagement within and upon a surface of an interior panel 23 of a vehicle door 22 . Neither the interior panel 23 nor the vehicle door 22 constitute a part of the instant invention. Such mechanical engagement can be achieved by any suitable fastening means, for example a combination of brackets, screws, rivets, clips or the like, which are affixed within an interior or hidden portion of the vehicle door panel, at various points where the surfaces come together. Alternatively, it is contemplated that the storage compartment could be provided with integral attachment means, such as deformable tabs (not shown) or the like which would enable secure engagement of the storage compartment 100 , upon insertion within said vehicle door panel. Placement of said storage compartment 100 within and upon said interior panel 23 , as illustrated, provides a storage area which is at least partially recessed within an interior portion 24 of the vehicle door. Referring to FIGS. 4 and 7 , the construction and arrangement of the instant invention is such that it cooperates with the door window 54 to slide the storage area 100 outwardly from the interior area 24 of the door 23 during downward movement of the window and inwardly into the door cavity during upward movement of the window.
Referring to FIG. 3 illustrating a preferred embodiment of the present invention, the back panel member 14 includes a back surface 16 , opposite sides 18 and 20 , a top 26 and a bottom 28 . The sides, top and bottom each extending generally perpendicular to the back surface 16 . In a most preferred embodiment the sides, top and bottom surfaces extend about one and one half inches from the back surface and are constructed and arranged to telescope inwardly and outwardly with respect to the center member 12 . The back panel member 14 also includes a means for pressing the back panel member into the center member 12 in a telescoping manner during downward movement of the vehicle door window 54 ( FIGS. 4 and 7 ), illustrated herein as a ramping surface 36 . The ramping surface 36 extends between the top 26 and back 16 surfaces to cooperate with the window 54 located within the vehicle door 22 . The back panel member 14 also includes a means for pressing back panel member outwardly with respect to the center member 12 and into the door cavity 24 during upward movement of the vehicle door window 54 . In the preferred embodiment the means for pressing the back panel member outward includes a plurality of spring members 56 located within spring pockets 58 integrally formed within the center member 12 . The back panel member is preferably constructed of a polymeric material by methods well known in the art such as injection molding. The back panel member may also include an integrally formed or securely attached padded surface (not shown) to protect articles stored within the storage compartment.
The front panel member 10 includes a front surface 30 having an aperture 31 therethrough for placing articles within the storage compartment 100 , opposite sides 32 and 34 , a top 72 and a bottom 78 . The front member 10 also preferably includes a covering means 42 movable between a first open position, wherein articles may be placed within the storage compartment, and a second closed position, wherein the covering means is juxtaposed to and covering the aperture 31 .
The center member 12 is constructed and arranged for mechanical engagement within and upon a surface of an inner panel 23 of a vehicle door 22 . The center member 12 having opposite sides 44 and 46 , a top 48 and a bottom 50 for connecting peripheral portions of the front and back panel members 12 , 14 so that the panel members face each other to form front and back inner boundaries of an interior portion of the storage compartment. In the preferred embodiment the sides 18 and 20 , top 26 and bottom 28 of the back panel member 14 are constructed and arranged to telescope inwardly and outwardly within the sides 44 and 46 , top 48 and bottom 50 of the center member 12 . Extending at least partially around the perimeter of the center member 12 is a means of attaching the center member to the inner surface of a door panel illustrated herein as a flange 40 . The flange preferably includes a plurality of apertures 52 for fasteners well known in the art.
FIGS. 1 through 11 illustrate alternative embodiments of the covering means 42 . Referring to FIG. 8 , the covering means 42 is illustrated in the form of a flexible flap 60 . In this embodiment, the flexible flap is flexibly engaged with the front panel member 10 so as to enable the flap 60 to be lifted to gain access to the interior storage area. The flap may also include a fastening member 62 to releasably engage the front panel member 10 . In this embodiment the front surface 30 may be constructed of a flexible material or rigid material or a suitable combination thereof.
Referring to FIG. 9 , the covering means 42 is illustrated in the form of a rigid plate 64 . In this embodiment the rigid plate 64 is pivotally connected via a hinge 66 to the front panel member 10 so as to enable the rigid plate 64 to be opened to gain access to the interior storage area.
Referring to FIG. 10 , the covering means 42 is illustrated in the form of a plurality of narrow elongated rigid elements 68 flexibly connected in an adjacent relationship. The terminal elongated rigid element 70 being flexibly connected to the front panel member 10 so as to enable the covering means to be retracted to a position juxtaposed to the sides 32 - 34 , top 72 or bottom 78 of the front panel member to gain access to the interior storage area.
Alternatively, the plurality of narrow elongated rigid elements 68 may be arranged to wind around an axle 72 ( FIG. 3 ) in a series of concentric loops 74 ( FIG. 4 ) in cooperation with a spring retraction mechanism 76 ( FIG. 3 ). Referring to FIG. 11 the covering means 42 is illustrated having a plurality of elongated rigid elements 68 arranged to form a plurality of accordion-like folds. The terminal fold 72 being connected to the front panel member 10 so as to enable the covering means 42 to be retracted to a position juxtaposed to the sides, top or bottom of said front panel member to gain access to the interior storage area.
Referring to FIGS. 2 and 3 the covering means 42 is illustrated in the form of a flexible sheet 78 . In this embodiment, the flexible sheet is flexibly engaged with the front panel member 10 so as to enable the sheet 78 to be lifted to gain access to the interior storage area.
Alternatively, the flexible sheet 78 may be arranged to wind around an axle 72 ( FIG. 3 ) in a series of concentric loops 74 ( FIG. 4 ) in cooperation with a spring retraction mechanism 76 ( FIG. 3 ).
Referring to FIGS. 5-7 a further alternative embodiment of the covering means 42 is illustrated. In this embodiment the covering means includes a pleated 80 front surface 30 and a lid member 82 to gain access to the interior storage area. The lid member 82 further includes a keyhole slot 84 constructed and arranged to cooperate with a pin member 86 in the front surface 80 and a hingedly connected bottom 78 to allow the front panel member to substantially flattened against the inner door panel 23 . Releasing the pin member 86 from the lid member 82 allows the bottom 78 to pivot downwardly thereby increasing the internal storage space.
All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.
It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and drawings/figures.
One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.
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This application is directed to a dynamic storage compartment for modifying the interior space of a vehicle, either as originally equipped or as an after-market modification, so as to provide a means for providing enhanced storage capacity for a vehicle which is characterized by ease of use and the ability to provide secure out of sight storage for valuables.
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This application is a continuation-in-part of application Ser. No. 08/970,196, filed Nov. 14, 1997, now U.S. Pat. No. 60/024,147 which application is based in part upon Disclosure Document No. 373320 dated Mar. 8, 1995 and Provisional Patent application, Ser. No. 60/030,914, filed on Nov. 14, 1996, and a cont. of PCT/US97/209,38 Nov. 14, 1997.
FIELD OF THE INVENTION
The present invention relates to monolithic in situ field-applied roofing surface membranes. Preferably, the surface membrane is a fabric or fiberglass imbedded low rise polyurethane adhesive covered by a waterproof and ultraviolet resistant coating, such as a silicone coating.
The present invention also relates to a new and useful method and industrial robotic device for applying coatings or other spray coated layers, in uniform thicknesses and at appropriate angles of pitch, in field applications, such as roofing applications or pavement applications.
BACKGROUND OF THE INVENTION
In the roofing applications, flat roofs are often made of polyurethane foam layers, which may be covered by various coatings, such as elastomeric coatings, such as silicone. It is difficult to maintain a uniform thickness when applying a foam or elastomeric material, which by its nature rises when applied to achieve a thickness above a roof base.
Furthermore, the faster that a foam applicator passes over a surface, the less volume of foam is applied, resulting in less of a thickness of the applied foam. To achieve thicker foam layers, a spray applicator is slowed down in velocity as it passes over the roof bases, so that more foam material is discharged per square unit of space of roof base being passed over by the spray applicator.
Various attempts have been made to apply foam uniformly, such as from an applicator moving at a uniform speed along a carriage track. However, at the end of each pass of an applicator over a portion of a roof base, the discharged foam is applied twice, i.e. once at the end of the pass to the edge, and again as it starts over above the previously applied foam, until the carriage can adjust to an unsprayed area.
Field applied roofing foam surface membranes are rigid polyurethane foam surface membranes, such as manufactured by Stepan Company of Pennsylvania under the trade name STEPANFOAMS®.
Stepan Company also manufactures a roofing product known as “low rise polyurethane adhesive”, brand name number RS 9514B, which is a concentrated polyurethane foam type adhesive often used to adhere solid rubber roof substrates to flat roof substrate structures.
However, it has not been known to imbed a low rise polyurethane adhesive with a woven polyester fabric or fiberglass layer and coat the formed substrate with silicone to create a monolithic integral roofing surface membrane for flat roofs, without the need for attaching a prefabricated roofing sheet, such as of vulcanized rubber, to the underlying roof substrate.
Furthermore, Dow Corning Corporation of Midland, Michigan manufactures silicone-based roofing coatings for weatherproofing reasons and for resisting the effects of ultraviolet light, such as the POLYCOAT® R-4000 silicone roof coating. Other prior art coatings are described in U.S. Pat. No. 3,607,972 of Kiles, et al, assigned to Dow Corning corporation, such as a room temperature vulcanizable siloxane-based block copolymer.
U.S. Pat. No. 5,253,461 of Janoski, assigned to Tremco, Inc. describes a cold-process built-up roofing system, which includes a curing adhesive with tarpaper and asphalt. The adhesive in its uncured state is substantially flowable, comprising asphalt and a compatibilizer and optionally a filler, dispersed in a curable polyisocyanate prepolymer. However, in Janoski '461 the adhesive takes up to 10 hours to cure, unlike spontaneously cured polyurethane-based foams.
Among prior art devices for applying coatings include U.S. Pat. No. 5,381,597 of Petrove which describes a wheeled robotic device for installing shingles on roofs. While it does not concern spraying of urethane foam upon a flat roof, it does describe a movable, wheeled carriage for use upon a roof.
U.S. Pat. No. 5,620,554 of Venable, assigned to Carlisle Corporation of Syracuse, N.Y. describes an apparatus for making a composite roofing material, including a reel support for reels of prefabricated vulcanized rubber sheets, a polymeric film and fleece matting, wherein rollers advance the solid rubber sheet from its reel, which heat and stretch the rubber, binding it to the polymeric film and fleece matting.
However, in Venable '554, there must first be a reel of a prefabricated solid rubber sheet, not an spontaneously formed monolithic roofing surface membrane.
Moreover, U.S. Pat. No. 5,872,203 of Wen describes a polyurethane adhesive for bonding polymeric roofing sheets to flat roof decks, which includes a two-component curable mixture, such as a polyurethane prepolymer and a polyol.
In addition, British patent application GB 2,055,326A of CCG Roofing Contractors, Limited describes a prefabricated polymer board that includes two layers with a fabric mesh therein. However, the fabric mesh is mechanically imbedded between the two layers during fabrication forming, and does not describe imbedding a fabric spontaneously within a polyurethane foam as the spray-applied foam rises up and through the fabric.
U.S. Pat. No. 5,248,341 of Berry concerns the use of curved walls to accommodate spray paint applicators for curved surfaces, such as aircraft.
U.S. Pat. No. 5,141,363 of Stephens describes a mobile train which rides on parallel tracks for spraying the inside of a tunnel.
U.S. Pat. No. 5,098,024 of MacIntyre discloses a spray and effector which uses pivoting members to move an armature which holds a spray apparatus.
U.S. Pat. No. 4,983,426 of Jordan discloses a method for the application of an aqueous coating upon a flat roof by applying a tiecoat to a mastic coat.
U.S. Pat. No. 4,838,492 of Berry discloses a spray gun reciprocating device, wherein parallel tracks are used wherein each track is square in cross section, but further wherein each track guides a plurality of rollers thereon.
U.S. Pat. No. 4,630,567 of Bambousek discloses a spray system for automobile bodies, including a paint booth, a paint robot apparatus movable therein, and a rail mechanism for supporting the apparatus thereat.
U.S. Pat. No. 4,567,230 of Meyer describes a chemical composition for the application of a foam upon a flat roof.
U.S. Pat. No. 4,167,151 of Muraoka discloses a spray applicator wherein a discharge nozzle is moved transversally upon a frame placed adjacent and parallel to the surface having the foam being applied thereto. However, the applicator of Muraoka '151 does not solve the problem of excess foam being applied at the end of each transverse pass of the discharge nozzle.
U.S. Pat. No. 4,209,557 of Edwards describes a movable carriage for a nozzle applying adhesive to the back of a movably advancing sheet of carpeting. Similarly, Australian Pat. No. 294,996 of Keith describes a movable carriage for a nozzle applying a polyurethane foam coating to a movably advancing sheet.
U.S. Pat. No. 4,016,323 of Volovsek also discloses the application of foam to a flat roof.
U.S. Pat. No. 3,786,965 and Canadian Pat. No. 981,082, both of James, et al, describe a self-contained trailer for environmentally containing a dispenser for uniformly dispensing urethane foam upon a terrestrial surface, wherein the problem of “skewing” occurs at the completion of each pass at the boundary edges of the surface to which are urethane foam is being applied. James '965 employs self-enclosed gantry robots to move the fluid discharge nozzle over the terrestrial surface.
U.S. Pat. No. 3,667,687 of Rivking discloses a foam applicator device.
U.S. Pat. No. 1,835,402 of Juers describes an apparatus for spraying glass from a nozzle transversely along a flat surface and U.S. Pat. No. 3,027,045 of Paasche discusses a coating machine where the nozzle moves by a pivot arm.
U.S. Pat. No. 3,096,225 of Carr discloses a hand-held spray nozzle for depositing a continuous stranded material, such as glass.
U.S. Pat. No. 2,176,891 of Crom discloses an apparatus for applying coatings over curved surfaces, such as within ditches or other curved surfaces. Moreover, U.S. Pat. No. 4,210,098 of Harrison also discloses an apparatus for spraying insulation or other coatings upon curved surfaces.
Other related art includes U.S. Pat. No. 2,770,216 of Schook for a pivotable spray nozzle, U.S. Pat. No. 3,548,453 of Garis for a transverse spray apparatus, U.S. Pat. No. 3,705,821 of Breer for a transverse spray apparatus, U.S. Pat. No. 3,867,494 of Rood, et al, also for a transverse spray apparatus, U.S. Pat. No. 3,885,066 of Schwenniger for a spray apparatus with a plurality of nozzles and U.S. pat. No. 3,923,937 of Piccoli, et al, for a centrifugally moving spray nozzle.
U.S. Pat. No. 3,954,544 of Hooker describes a method of applying a membrane covered rigid foam and a method of bonding a sheet or web, and U.S. Pat. No. 4,659,018 of Shulman discloses an orbiting nozzle apparatus.
U.S. Pat. No. 4,474,135 of Bellafiore discloses an apparatus for spraying a coating upon a spherical object supported by a post, which apparatus includes a curved track for providing orbital movement of a spray applicator about the exterior spherical surface of the sphere to be coated. While they are curved in nature, the curved tracks thereof are provided for orbital movement about the sphere, not to change the speed, tilt and direction of a linearly moving nozzle.
Another attempt to solve the problem of “double spraying” at a pass edge has been described in U.S. Pat. No. 4,333,973 of Bellafiore, which describes a similar spray applicator, such as that of Autofoam® Company. This spray applicator includes a wheeled, self-movable vehicle having a carriage portion with a horizontal linear track thereon. The spray applicator moves from one end of the track to the other, opposite end of the track at the end of one pass, of the applicator, above a portion of a roof base, and then the applicator reverses direction upon the track.
However, to avoid the “double spraying” problem noted above, the Autofoam® device has an on-off switch which turns the applicator off at an appropriate time at the end of a pass while the applicator is reversing direction, and re-starts the applicator a short time later when the applicator has started to move in the opposite direction.
Moreover, there are severe problems with this approach, as the constant “on-off” starting and re-starting of the applicator causes fatigue to the metal or other material parts of the applicator, and a detrimental effect to the end product. In addition, the Bellafiore '973 and Autofoam® devices are bulky and complicated to use.
In addition, while monolithic field applied, spontaneously sprayed polyurethane foam roofing surface membranes are convenient, they use up considerable amount of material in creating the roofing surface membrane.
OBJECTS OF THE INVENTION
Therefore, the objects of the present invention are as follows:
It is an object of the present invention to provide a monolithic, unitary integral roofing surface membrane from a combination of a low rise polyurethane adhesive, a reinforcing mesh and a weather proofing and ultraviolet resistant coating.
It is also an object of the present invention to provide a thin monolithic reinforced roofing surface membrane which cures spontaneously.
It is also an object of the present invention to provide a thin but durable reinforced roofing surface membrane for roofs.
It is yet another object of the present invention to provide a method of applying a fabric or fiberglass mesh within a spontaneously curable polymer roofing surface membrane while the polymer is being spontaneously cured at a roofing field application.
It is further an object of the present invention to provide a method and apparatus for providing monolithic fabric and/or fiberglass reinforced roofing surface. membranes.
It is another object of the present invention to provide a spray applicator for foam roofing which applies a coating of elastomeric foam of uniform thickness.
It is also an object of the present invention to provide a single yet efficient spray applicator for foam roofing.
It is also an object of the present invention to provide a spray applicator that can be disassembled into a few major parts for easy transport and reassembly on a roof without resorting to the use of a crane.
It is yet another object of this invention to provide a method for covering a large area of a roof with foam roofing using a continuous spray.
It is also an object of the present invention to provide a spray applicator with a nutating nozzle mount to minimize variations in coating thickness.
It is a further object of the present invention to provide a hand-held remote control to enable the spray applicator vehicle to operate without an on-board operator.
It is an object of the present invention to provide a method for continuous adhesive spraying and application of elastomeric sheet roofing material of large strip areas of a roof.
It is a further object of the present invention to provide accessories for the spray applicator vehicle to permit its use for applying elastomeric sheet roofing material from a roll.
It is also an object of the present invention to improve over the disadvantages of the prior art.
SUMMARY OF THE INVENTION
In keeping with these objects and others which may become apparent, and to solve the problems inherent in the Bellafiore '973 and Autofoam® spraying devices, the present invention uses one or more track rails, such as a double linear track of round cross section, as shown in the drawings herein, to continuously apply monolithic polyurethane roofing surface membranes.
In one embodiment, there is an arcuate uphill end portion of the track at each side, so that the spray applicator, which moves along the one or more linear tracks, will accelerate in speed and tilt the discharge nozzle outward as it rolls up the curved uphill portion, thereby reducing the amount of foam applied to the edge portion of the roof at the end of a pass of the applicator.
To obviate the complicated mechanisms of the Autofoam® device, the present invention uses simple mechanics to move the spray applicator. For example, a transverse linear movement means, such as, a radially extending swinging arm, is provided for the sideways movement of the applicator along the track. To eliminate arcuate movement of the pivoting arm, the transverse linear movement means may have a telescoping mechanism or other gear assembly, so that the spray applicator moves linearly, instead of arcuately. For example, the swinging arm moves about a pivot fulcrum point.
Other transverse movement mechanisms may be used, such as rack and pinion devices.
To further insure uniform thickness, the present invention further comprises various speed controls, so that an appropriate thickness can be applied for each pass.
For example, a rheostat controls the speed of the movement of the spray applicator, and an LED readout tachometer has a display dial with appropriate readings for appropriate speeds for corresponding desired thicknesses. Since the rate of flow of foam-producing material emanating from the nozzle is fixed, the ground movement speed of the applicator determines the weight of the coating per unit area applied. This, in turn, determines the thickness.
When a slope is desired on a flat roof, such as toward a drainage line, the ground speed of the foam applicator can be reduced on each successive pass away and parallel to the drainage line. This will result in a stepwise slope approximating the desired contour.
It has been found that a nutating nozzle holder, which tilts the nozzle a small amount cyclically as it traverses the track, can be used to minimize the variations in foam thickness (in the form of rounded ridges) due to the hollow-cone pattern of the nozzle.
Accessories can be added to the spray applicator so that it can be adapted for spraying adhesive on a roof or for automatically laying an elastomeric sheet covering such as Sure-SealTm™ Fleece Back 100 EPDM made by Carlisle SynTec Incorporated of Carlisle, Pa. over a polyurethane foam substrate. Accessories can also be added for imbedding reinforced fabric within the polyurethane foam substrate.
In one embodiment, the primary roofing surface membrane is a polyurethane foam, such as STEPANFOAMO® of Stepan Corporation. In this embodiment, the average thickness of the deposited foam is about two inches in thickness.
However, in the preferred embodiment, instead of a standard polyurethane foam roof surface membrane of about 2 inches in thickness, the preferred monolithic roof surface membrane is much thinner, rising to a thickness of about one quarter (¼) inch in thickness.
This is because, instead of using standard polyurethane foam such as STEPANFOAMS®, what is used is what is known in the trade industry as a “low rise polyurethane adhesive”, such as brand name number RS9514B, also manufactured by Stepan Corporation.
Previously, low rise polyurethane adhesives have only been used to act as an adhesive to adhere prefabricated roofing, such as vulcanized rubber sheets, to roof deck surfaces.
These low rise polyurethane adhesives have not previously been used as a component of a monolithic roofing surface membrane itself.
The combination of low rise polyurethane adhesive with a reinforcing mesh and a silicone-based coating obviates the need for a thick polyurethane foam base of about two inches.
Therefore, the present invention includes a field applied, monolithic roofing surface membrane, which includes a combination of a low rise polyurethane adhesive with a fabric or fiberglass mesh adding reinforcement thereto, such as a woven polyester, i.e., what is known as a 6 or 10 ounce fabric mesh.
The mesh is applied to the low rise polyurethane adhesive from a rolling reel and is embedded within the polyurethane adhesive by virtue of the rising, spontaneously cured polyurethane adhesive contacting and rising through the recess spaces between the fabric or mesh structural fibers, thus encasing the mesh within the polyurethane adhesive during the curing of the polyurethane adhesive.
In the preferred embodiment of the present invention, a subsequent application of a silicone-based coating is applied also by spray nozzle over the already-deposited and mesh reinforced low rise polyurethane adhesive surface membrane.
This silicone coating adds a seal for weather proofing the underlying mesh reinforced polyurethane adhesive layer and for resisting damage from ultraviolet light. A typical silicone coating is POLYCOAT 4000 of Dow Corning Corporation, or as described in U.S. Pat. No. 3,607,972 of Kiles, et al, assigned to Dow Corning Corporation.
When the silicone coating is applied, it has a thickness of about 20 mils. The thickness of the reinforcing mesh layer and the silicone coating together is about 30-100 mils. The total thickness of the preferred monolithic roofing surface membrane, including the silicone coating and the mesh-reinforced polyurethane adhesive, is about one quarter (¼) inch in thickness, which is significantly thinner than the two (2) inch thickness of a spray applied foam roofing substrate.
While the invention has been described for use in applying roofing materials on roofs, it is also usable for spray applications at ground level such as for pavement painting or sealing applications.
DESCRIPTION OF THE DRAWINGS
The present invention can best be described in conjunction with the accompanying drawings, in which:
FIG. 1 is a top plan view of a spray applicator vehicle of the present invention;
FIG. 2 is a side elevation of a spray applicator vehicle of the present invention;
FIG. 3 is a side cross section detail of a transverse rail and carriage;
FIG. 4 is an end elevation of a transverse rail and carriage;
FIG. 5 is a block diagram of a spray applicator electrical system;
FIG. 6 is an end cross section of a coated roof with a central drain ridge;
FIG. 7 is a block diagram of a spray applicator electrical system using a hand-held remote control;
FIG. 8 is a nozzle spray pattern and resultant foam cross section;
FIG. 9 is a nutating spray nozzle feature with details thereof; wherein
FIG. 9A is a side elevation of a nozzle holder and an actuator cable; and,
FIG. 9B is a top plan view of a cam and cam follower;
FIG. 10 is a side elevation of a spray applicator as adapted for laying elastomeric sheet roofing material; and,
FIG. 11 is a side elevation of a spray application vehicle as adapted for applying fabric or mesh reinforced foam coating.
FIG. 12 is a cross-sectional view of a monolithic field-applied, mesh-reinforced polyurethane foam roofing surface membrane of the present invention; and
FIG. 13 is a cross-sectional view of a monolithic field-applied, mesh-reinforced low rise polyurethane adhesive and silicone-coated roofing surface membrane of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIGS. 1-2, spray applicator 1 is used for applying polyurethane foam coatings or other spray coated layers, such as low rise polyurethane adhesives, in uniform thicknesses in field applications, such as roofing applications or pavement applications.
As shown in FIGS. 1 and 2, spray applicator vehicle 1 includes frame 2 , operator seat 5 , steerable powered single wheel 50 , two unpowered side wheels 4 , swinging boom 18 , transverse rail subassembly 23 and various associated parts of nozzle 62 attached to carriage plate 26 . Motor 6 drives sprocket 52 of chain 8 through gear reduction box 7 to provide vehicle motion via wheel sprocket 51 . The operator steers the vehicle 1 by steering wheel 9 , which moves steering linkage bar 57 , thereby rotating wheel flange 58 . Boom 18 is continuously reciprocated from pivot point 20 on tower 55 by crank arm 16 which is cyclically moved by reduction gear box 13 powered by motor 12 , via adjustable linkage arm 14 . Linkage arm 14 is attached to output shaft 17 and is rotated at a constant speed as determined by settings in control box 11 . Slot 15 permits adjustment of the lateral movement limits of telescoping end 19 of boom 18 . Rails 24 and 25 constrain the movement of carriage plate 26 to a linear path transverse to frame 2 . Other transverse movement means may be used, such as rack and pinion gear assemblies.
Control box 11 also sets the ground speed of vehicle 1 . Hose 35 , which may consist of two or more separate hoses or individual lumens, carries liquid materials, such as polyurethane foam or low rise polyurethane adhesive, for spraying through nozzle 62 from a remote pressurized source.
For polyurethane foam, or low rise polyurethane adhesive, two chemicals supplied from separate hoses 35 are mixed at the nozzle 62 just prior to discharge. The two liquids interact chemically causing an exothermic foaming and hardening reaction.
Hose 35 is retained in boom bracket 37 and may also be attached in one or more places by hook and loop straps 36 . In normal use, a second (non-riding) work person guides hose 35 . Solenoid 38 , actuated by a switch in control unit 11 , operates the discharge valve at nozzle 62 .
It can be appreciated that vehicle 1 rolling at a constant speed with transverse movement means, such as boom 18 , reciprocating continuously, is able to spray a continuous strip of coating on a surface. If the discharge rate at the nozzle is held constant, the amount of product sprayed on a surface per unit of sprayed area can be set by goselecting ground speed.
Since the transverse movement means, such as a boom or other assembly, changes direction at the distal ends of its swings, a method is employed to limit the amount discharged to prevent “double coating” at the edges.
As noted before, prior art systems, such as described in Bellafoire '973 and of Autofoam® Company, shut the nozzle off at these portions of the cycle. However this action causes several problems.
For example, the on/off cycling has detrimental effects on spray material consistency from a chemical reaction point of view. The on/off cycling also causes mechanical wear and induces metal fatigue on brackets that must react to cyclic pressure loading.
In contrast to the devices of Bellafoire '973 and of the Autofoam® Company, the present invention uses a geometric arrangement and constant and continuous liquid product flow to prevent pattern edge build-up.
For example, FIG. 3 shows a cross section of rails 24 and 25 in the middle of the transverse sweep. Carriage plate 26 , driven by end bushing 27 on telescoping extension 19 , is shown with brackets 65 and 66 attached. Brackets 65 secure top rollers 29 with concave “hourglass” contours. Similarly contoured bottom rollers 53 are secured by brackets 66 . Thus rollers 29 . and 53 capture rails 24 and 25 constraining plate 26 to roll along these rails. Plate 26 also supports nozzle holder assembly 34 (not shown in this figure).
FIG. 4 shows an end view of one embodiment of rail subassembly 23 . While rails may be flat, preferably both rails 24 and 25 are curved at their distal ends in a constant radius. Nozzle assembly 34 is shown in a flat vertical spray location at “A” and at an oblique spray location at the extreme limit of travel on the curved portion at “B”. Top rollers 29 and bottom rollers 53 are offset from each other to facilitate easy rolling without binding on the curved portions. If the transverse movement means, such as boom 18 or other gear assembly, is reciprocated at an essentially constant rate, the carriage assembly is accelerated at the ends of travel due to the greater distance traveled per unit time on the curved end contour as well as the change in direction. Furthermore, the angle of nozzle 62 is tilted outward at the end so that the coverage area “BB” is larger than that of “AA”. These end factors combine to reduce the thickness of the sprayed layer so that the “double layering” at the edge of each applied band of polyurethane foam or low rise polyurethane adhesive can be controlled to result in an edge thickness essentially the same as that of the center portion of a pass. This can be adjusted empirically based on the particular batch, temperature and other field conditions. The adjustment is the end limit position of nozzle 62 relative to the track end curve as determined by the adjustment of crank arm 16 in slot 15 of linkage arm 14 .
Spray vehicle 1 is designed to be easily disassembled into four subassemblies for easy transport to the roof of a building on an elevator or by using a winch. Prior art systems require a crane. Booms 18 and 19 can be lifted off as a unit by removing spring pin 22 from upright link 54 , spring pin 21 from pivot shaft 20 and spring pin 28 from carriage plate 26 coupling.
A front subassembly including of track subassembly 23 with uprights 3 can be removed by removing two spring pins 30 from frame member 2 .
Central frame 2 subassembly including wheels 4 can be separated from the driven wheel subassembly (including seat 5 and steering wheel 9 ) by removing large spring pin 60 from socket member 59 on the frame subassembly. Then back chassis 10 can be lifted free. Electrical connections tying the various subassemblies have connectors which must be disconnected. The four subassemblies can then be reassembled on the rooftop.
FIG. 5 shows a block diagram of the electrical system largely housed in control box 11 . The spray applicator vehicle 1 is electrically operated by connection to standard AC mains (typically 115 VAC at 60 HZ) via plug 40 and extension cord 39 . A portable engine operated generator can supply this power as an alternative. Although two separate modular AC/DC converters 76 and 83 are depicted, a single converter can supply current to all DC loads.
An AC power switch 75 controls power to the entire spray applicator vehicle 1 . Converter 76 supplies DC to a unidirectional speed control 77 with digital speed indicator 78 and speed set control 79 . For maximum consistency of application, speed control 77 is preferable a PID type of feedback servo control which maintains output speed of motor 12 (for moving the transverse movement means, such as via the swinging of boom 18 or otherwise,) constant via feedback from encoder 80 mounted on motor 12 .
Switch 81 controls power to a solenoid 82 which opens the discharge valve at nozzle 62 . Converter 83 supplies DC power to a bidirectional PID speed control 84 with digital speed indicator 85 and speed set control 86 . This control accurately and repeatedly maintains the ground speed in either direction of spray applicator vehicle 1 as set even under varying load conditions by virtue of feedback encoder 87 mounted on motor 6 .
This operation is used during the spraying operation and determines the thickness of the resulting sprayed layer.
Control switch 89 determines the direction of movement as forward or reverse.
A second manual bidirectional speed control 90 is used to quickly select the desired ground speed via alternate manual control 91 when it is desired to maneuver spray applicator vehicle 1 prior or after a spray application.
In this manner, the carefully selected “automatic” setting for spraying is not altered. Either automatic speed control 84 or manual speed control 90 is actively enabled at any one time via selector switch 88 .
The repeatable application of a desired amount of coating per pass permits the type of roof foam or low rise polyurethane adhesive surfacing depicted in FIG. 6 . This is an exaggerated cross section of the end of a roof 61 surface with a central drain 96 ditch with grate cover 95 . If the roof 61 had a flat pitch, it would be desirable to create a pitch toward the drainage ditch for more effective drainage. This can be approximated by a stepped foam or low rise polyurethane adhesive layer as shown, starting from lowest strip “A” and rising in thickness to strip “E” of the thickest cross section farthest from central drain 96 . These strips can be applied in a single pass or in multiple passes by spray applicator vehicle 1 where the ground speed for layer “A” is fastest and the speed is reduced for each successive layer “B”,“C”,“D” “E” and “F”.
For safety reasons, federal OSHA occupational safety regulations stipulate that a powered vehicle cannot be ridden by a workperson within ten feet of the edge of a roof. Also, a workperson is required to guide hose 35 while the operator rides and guides spray applicator vehicle 1 . For these reasons, it would be desirable to operate spray applicator vehicle remotely. In this manner, a single workperson controls spray applicator vehicle 1 and guide hose 35 .
FIG. 7 shows such a remote control configuration. Control box 11 is replaced by a hand-held remote control box 100 with a face plate and several vehicle mounted functional units. Since the operator is no longer physically on spray applicator vehicle 1 , electric steering ram 102 replaces the steering wheel. Electric steeling ram 102 is controlled by positional steering control 101 , which sets the position of steered wheel 50 to match that of steering control wheel 106 on remote control box 100 .
Communications between remote control box 100 and spray applicator vehicle 1 is via coiled cable 105 , although a fail-safe radio communications channel can be used as well. To limit the number of individual conductors in cable 105 , a multiplexor/demultiplexor module 103 and 104 is used at each end of cable 105 to facilitate the two way communications. The function of similarly numbered components is the same as that explained above in reference to FIG. 5 .
Hollow-cone nozzle 62 sprays a pattern 110 of polyurethane foam or low rise polyurethane adhesive that impinges on the ground as shown in FIG. 8 . As this pattern is swept sideways in a single pass, it will lay material that is denser toward the top and bottom edges resulting in a cross section with ridges 111 and valley 112 in the “Y” direction from roof surface 61 .
While multiple sweeps by boom 18 mitigate this effect somewhat, ridges in the final sprayed surface still persist. This problem is eliminated by nutating or cyclically rocking the nozzle mount 34 slightly at right angles to rails 24 and 25 several times during each sweep to even out the coverage of hollow-cone nozzle 62 over multiple sweeps.
FIG. 9 shows optional modifications to accomplish this. The detail of FIG. 9A shows modified bracket 120 with pivot 121 holding nozzle mount 34 . Bracket 120 is fastened to carriage plate 26 . A push-pull cable assembly including armored housing sleeve 123 with cable 122 within is used to actuate the cyclic motion illustrated by the phantom representation (shown in broken lines) of nozzle holder 34 at the extreme outward position. The detail of FIG. 9B shows the powering end of cable 122 . Bracket 126 , attached to the frame of vehicle spray applicator 1 in the vicinity of gear box 13 , retains sleeve 123 . Cam follower 130 is pivoted at pivot point 128 within adjustment slot 127 and is biased toward multiple lobe cam 131 by spring 129 . The stroke of wire 122 (and therefore the amount of cyclic tilt of nozzle holder 34 ) is determined by the dimensions and geometry of cam follower 130 and the depth of lobes on multiple lobe cam 131 .
The proper centering of the motion of holder 34 is adjusted by moving pivot 128 within slot 127 . Multiple lobe cam 131 is attached to the output shaft of gear box 13 under arm 14 . It can be appreciated that cable wire 122 is cycled by each cam lobe as multiple lobe cam 131 rotates.
By moving cam follower 130 out of contact with multiple lobe cam 131 and tightening it in a locked position, to defeat the pivoting, nozzle holder 34 can be locked in a vertical position to defeat the nutating feature.
Alternatively, a separate small gear motor and crank coupling (not shown) mounted right on bracket 120 can be used to actuate the nutating action without need of cable 122 .
Spray applicator vehicle 1 is easily modified to adhesively bond sheet elastomeric roofing material. As shown in FIG. 10, side arms 141 are pivoted at pivot point 140 from side extensions (not shown) which are attached to frame 2 . These arms 141 have telescoping extensions 142 which are locked with hand screws 143 . A roll of elastomeric sheet 144 is pivoted at the end of arms 142 at pivot point 148 , with sheet end 145 trailing roll 144 as vehicle spray applicator 1 moves in the direction of arrow 149 . Also pivoted at pivot point 148 are side arms 146 which trail a weighted roller 147 , which weighted roller 147 applies even pressure to sheet layer 145 . Nozzle 62 sprays a layer of bonding adhesive which bonds sheet 145 to roof surface 61 .
Alternately, roll 144 can be adjusted to apply a skin coating of rolled material over the solidified foam layer applied from nozzle 62 to a surface, such as a roof.
Adjustment of extensions 142 determine the distance X between the sheet contact and the sprayed roof surface a fixed distance from the center of the spray cone. Since the vehicle moves at a predetermined constant speed, distance X can be used to match the optimal delay from adhesive application to contact of the sheet roofing material.
A method for applying reinforced foam or polyurethane adhesive roofing involves the use of a reinforcing fabric or open fabric mesh. The fabric can be manufactured of a variety of fibers such as nylon, fiberglass, aramid, etc. The method involves spraying a foaming mixture and immediately imbedding the reinforcing fabric in the mixture before the foam rises so that the reinforcing fabric rises with the foam and is embedded in the foam layer.
FIG. 11 shows modifications of the spraying applicator vehicle 1 for accomplishing this task. Side arms 160 are rigidly attached to frame 2 and uprights 3 ; they flare out at the distal end to lie outside of the spray pattern on each side. Roll 164 of lightweight reinforcing fabric is pivotally attached at the end of arms 160 . The free end of fabric 165 is fed under light roller 162 , which contacts surface 61 just at the edge of the foam adhesive spray pattern. Spring plunger 161 supported by brace 163 forces roller 162 into contact with roof surface 61 . Foam spray 168 , prior to rising, is contacted with fabric 165 , which rises with foam 166 to embed itself in the foam layer as shown by the broken line.
FIGS. 12 and 13 show cross sectional views of portions of roofing substrates provided in the present invention.
For example, while a monolithic polyurethane foambased roofing surface membrane is at least 1-2 inches in thickness to provide a strong base, the preferred roofing surface membrane including a mesh-reinforced low rise polyurethane adhesive under a silicone coating can have a thickness of only about one quarter (¼) inch. This saves considerably in the amount and cost of material deposited.
In FIG. 12, polyurethane foam layer-based 168 is imbedded with mesh 165 and covered by silicone coating 175 . This provides a roofing surface membrane of about 1-2 inches in thickness.
In contrast, as shown in FIG. 13, a preferred embodiment of a much thinner monolithic roofing surface membrane of from about one quarter (¼) inch in thickness is provided with a base layer 178 of low rise polyurethane adhesive having mesh layer 165 therein and coated by silicone coating 175 for weatherproofing and for resisting the effects of ultraviolet light. Therefore, a substantial savings of material and cost is achieved without compromising the structural and sealing characteristics of the monolithic roofing surface membrane.
Mesh 165 is applied over the curable polymer during curing permitting the polymer to rise through and over recesses separating fibers within mesh 165 .
Mesh 165 may be a fabric such as woven polyester, nonwoven polyester, fiberglass, aramid, or nylon.
It is further noted that other modifications may be made to the present invention without departing from the scope as noted in the appended claims.
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A uniformly applied monolithic roofing surface membrane at appropriate thickness and pitch is field applied upon a surface. The surface membrane may be field applied from a spray applicator foam dispenser moving between two parallel tracks. The uniform application of foam at each pass is assured, by accelerating the speed of the foam dispenser at the end of each pass, by providing continuous movement of the spray applicator upon the tracks. The monolithic roofing surface monolithic thus formed includes a spontaneously curable polymer, such as low rise polyurethane adhesive or polyurethane foam, having a mesh such as of fabric or fiberglass therein, with a silicone coating thereon.
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BACKGROUND OF THE INVENTION
This invention relates to telecommunications apparatus and, in particular, to network interface units.
Network interface units constitute the demarcation between the customer's equipment and the telephone network. In buildings including multiple subscribers, the interlace unit is typically mounted in the basement and includes an array of customer bridges, each bridge being coupled to an individual subscriber line. The bridges are coupled to the phone network through an RJ11 jack and plug so that a customer can plug a working phone into the jack to determine if any equipment problems lie in the customer or network side of the telecommunications system.
Network interface units also include a building entrance protector portion which includes a cable splice chamber and a protector field for providing surge protection for each customer. The protector field is typically mounted adjacent to the array of customer bridges. (See, e.g., U.S. Pat. No. 4,945,560 issued to Collins et al.) It has recently been proposed to include the protector field and splice chamber in the bottom layer of a multilayer unit with the customer bridges in the top layer. (See U.S. patent application of Daoud, Ser. No. 08/040,772, filed Mar. 31, 1993, and assigned to the present assignee.)
It has also been suggested to include a housing attached to the RJ11 jack of a customer bridge, which housing could include a protector, a maintenance termination unit, or other types of electronic components. (See U.S. Pat. No. 5,222,908 issued to Baker, et al.) Suggestions have also been made to combine a modular jack and protector in a single housing. (See, e.g., U.S. Pat. No. 5,025,345 issued to Marks.) Further, it has been proposed to include a shield contact on a modular jack. The shield includes tails for mounting to a ground plane of a printed wiring board. (See U.S. Pat. No. 4,878,858 issued to Dechelette.)
SUMMARY OF THE INVENTION
The invention, in one aspect, is a network interface unit for servicing a multiplicity of subscribers. The unit comprises a chassis including a conductive portion with a first array of apertures therein, the portion including conductive members extending from a major surface of the portion on at least one edge of each aperture of the first array. The unit further includes a plurality of customer bridge assemblies, each including a jack and a housing mechanically coupled thereto with a protector included in the housing. Attached to the jack is a contact member with at least one contact finger extending from at least one side and electrically coupled to a ground contact of the protector. The jacks are inserted into corresponding first apertures so that the contact fingers make electrical contact with corresponding conductive members extending from the conductive portion.
In accordance with another aspect, the invention is a customer bridge assembly which includes a jack adapted for mounting in an aperture of a chassis, and a housing mechanically attached to the jack. The housing includes therein a protector comprising a ground contact. A contact member electrically coupled to the protector ground contact is attached to the jack. The contact member includes at least one contact finger extending from at least one side and adapted to make electrical contact with a conductive member extending essentially perpendicular to a major surface of the chassis.
BRIEF DESCRIPTION OF THE DRAWING
These and other features of the invention are described in detail in the following description. In the drawing:
FIG. 1 is a perspective view of a network interface unit in accordance with an embodiment of the invention;
FIG. 2 is an enlarged, partly cut-away view of a portion of the unit of FIG. 1;
FIG. 3 is another view of the portion of the unit shown in FIG. 2;
FIG. 4 is an exploded, perspective view of a portion of the unit shown in FIGS. 2 and 3; and
FIG. 5 is a perspective view of a portion of the unit of FIG. 1 with customer bridge assembly removed.
DETAILED DESCRIPTION
A typical interface unit, 10, is shown in plan view in FIG. 1. The unit includes an array of customer bridges, e.g., 11, mounted within respective apertures in a chassis, 12. The chassis is typically made of aluminum.
One of the bridges, 11, is shown in more detail in the views of FIGS. 2 and 3. As best seen in FIGS. 1 and 2, each bridge includes a connector portion, 13, which comprises a pair of screws, 14 and 15, electrically coupled to the customer's equipment by means of wires (not shown). The screws, 14 and 15, are also electrically coupled to a pair of wires, 16 and 17, formed within a protective jacket, 18, which emerges from the body of the connector portion, 13. The wires terminate in a standard RJ11 plug, 19. (For a more detailed discussion of a connector portion which may be used in a network interlace unit, see U.S. Pat. No. 5,004,433 issued to Daoud.)
Adjacent to each connector portion, 13, is a bridge assembly, 20, which includes a jack, 21, for receiving the RJ11 plug, 19. As best seen in the view of FIG. 3, mechanically attached to the jack, 21, by means of a flexible hinge, 23, is a housing, 22. The housing, 22, includes a hinged cover, 24, and a pair of sidewalls, 25 and 26, each sidewall including a slot, 27 and 28, respectively. The housing, 22, and jack, 21, are typically molded from a single piece of material such as plastic.
Included within the housing, 22, is a standard solid state surge protector, 30, such as AT&T's 3C1S surge protector. The protector, 30, is mounted to a circuit board, 31, and is electrically connected in parallel with the tip and ring wires, 32 and 33, from the jack, 21, and the tip and ring wires, 34 and 35, going to the telephone network. As shown, the tip and ring wires pass through respective slots, 27 and 28, in the sidewalls of the housing.
The ground connection of the protector, 30, is provided by means of a wire, 34, extending from a pad (not shown) on the board connected to the ground terminal of the protector. The opposite end of this wire, 34, is electrically coupled to a contact member, 40, which is mechanically attached to the surface of the jack, 21. The combination of the jack, 21, and contact member, 40, is illustrated in the exploded view of FIG. 4.
The contact member, 40, includes a terminal, 41, for receiving the ground wire, 34, from the protector, 30. The contact member, 40, further includes a pair of sidewalls, 42 and 43. Extending upward from the bottom of each sidewall, e.g., 42, is at least one and preferably a plurality of contact fingers, e.g., 44. (It will be noted that the contact fingers extending from the sidewall 43 are not visible in the view of FIG. 4, but can be seen partially in the view of FIG. 3.) The sidewalls 42 and 43 are inserted into slots, e.g., 45, in the jack, 21, so that the contact member, 40, is securely attached thereto. In order to resist pull-out, the rear edges, 46 and 47, of the sidewalls are serrated. The contact member is preferably made from a single piece of metal such as phosphor bronze or beryllium copper.
The chassis, 12, includes a series of apertures for receiving the bridge assemblies, 20. One of these apertures is illustrated as 50 in FIG. 5. As also shown in FIG. 5, as well as in FIGS. 2 and 3, a flat metal sheet, 51, is attached to the bottom major surface of the chassis by means of, for example, flat head rivets, e.g., 52. Typically, a single sheet will be provided for each row of bridge assemblies in the unit, 10. The sheet, 51, is electrically coupled to ground potential. The sheet, 51, includes a series of apertures, e.g., 53, which are aligned with corresponding apertures, e.g., 50, in the chassis. The apertures, 53, in the sheet, 51, are formed so that portions of the sheet extend downward from the major surface of the chassis to form conductive members, 54 and 55, on two sides of the aperture, 53, in this example extending essentially perpendicular to the surface of the chassis. (See also FIG. 3.) The conductive members, 54 and 55, could be formed on any number of sides according to particular needs. The conductive members, 54 and 55, typically extend approximately 1.3 cm from the major surface of the sheet, 51.
Once the protector, 30, is inserted in the housing, 22, the contact member, 40, is attached to the jack, 21, the tip and ring wires, 32 and 33, are coupled to the pins (not shown) of the jack, 21, through the plastic insert, 60, and the ground wire, 34, is coupled to the terminal, 41, of the contact member, 40, the bridge assembly is ready for insertion into the apertures, 50 and 53, in the chassis and ground sheet, respectively. This is accomplished by first inserting the housing, 22, through the apertures, 50 and 53. The flexible hinge, 23, will ensure that the housing follows the contours of the chassis, 12. A ledge, 61, on the outer surface of the jack, 21, will make contact with the surface of the chassis to prevent any further movement through the apertures. At the same time, a latch, 62, on the jack housing will engage the top edge of the aperture, 53, in the sheet, 51, to secure the jack, 21, in the aperture.
It will be noted that when the jack is secured in the apertures, 50 and 53, the contact fingers, e.g., 44, of the contact member, 40, will electrically and mechanically contact the conductive members, e.g., 55, of the sheet, 51. Thus, a ground connection is provided for the protector, 30, through the wire, 34, the contact member, 40, and the sheet, 51.
It will be appreciated that by integrating the protector into the bridge assembly, the need for a separate protector field is eliminated, and considerable cost reductions are realizable.
Various modifications will become apparent to those skilled in the art. For example, although a separate conductive sheet, 51, is described for providing a ground connection, the chassis body, 12, itself may provide the ground connection if it is made of a sufficiently conductive material. All such variations which basically rely on the teachings through which the invention has advanced the art are properly considered within the scope of the invention.
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Disclosed is a network interface unit where the protectors are mounted within a pouch attached to an RJ11 modular jack. The modular jack includes a contact member which electrically contacts a grounding strip on the terminal chassis to provide the necessary ground connection for the protector.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application is related to and takes priority from U.K. Patent Application No. 0222853.4, filed Oct. 3, 2002, commonly owned by the assignee of the present application, the entire contents of which are expressly incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to the control and classification of liquids in separating processes.
BACKGROUND OF THE INVENTION
[0003] When a centrifuge or similar apparatus is implemented to separate a mother liquid from solids, it is desired in a multitude of processes to wash the solids retained in the centrifuge or similar apparatus to remove either the vestiges remaining of the mother liquid and/or to purify the solids retained. This is achieved by introducing another liquid, a “wash liquid”, into the centrifuge after a quantity of the mother liquid has been removed by the centrifuge.
[0004] In using a centrifuge or similar apparatus in a process in which the solids are soluble in the wash liquid (referred to herein as Class X), the improved purification of the solids must be offset by the loss of the dissolved solids, the reduction in separation efficiency and the necessary process to separate the wash liquid from the separated mother liquid and recover any dissolved solids. An example of this situation is that of separating massecuite into sugar crystals and molasses. Whilst retaining the sugar crystals in the basket, the separated molasses and wash liquid require a further separation with minimal intermixing, to be processed in separate streams, the wash liquid being applied after the bulk of the molasses has been separated to wash the crystals to the required purity levels.
[0005] In a process involving a centrifuge or similar apparatus in which the solids are insoluble in a wash liquid (referred to herein as Class Y), the solids, after separation, may be washed to remove further mother liquid from its surfaces. The extent of the wash must be offset against the additional loading of the further separation stage that must be provided to remove the contaminants from the excess liquid used to wash the solids. An example of this situation is that of producing gypsum in flue gas desulphurisation processes. Washing during the centrifuge part of this process reduces the chloride contamination of the solids to produce high grade gypsum suitable for wall board manufacture. The mother and the wash liquids are mixed and reprocessed as an effluent.
[0006] The use of wash liquid in excess of the minimum required is known as “overwashing”. Overwashing is detrimental to the separation process and results in reduced separating efficiency, increased process cycle times, excess wash liquid usage, excess dissolution of solids, increased load on secondary effluent separating process or combinations of these.
[0007] Thus, the amount of wash liquid used affects the efficiency and economy of implementing a centrifuge.
[0008] It is known to seek to control overwashing by monitoring the liquid state as it leaves the centrifuge case. FIG. 1 of the accompanying drawings shows a typical industrial centrifuge comprising a perforated cylindrical basket/drum 10 which is rotatable about a vertical axis 12 on a motor driven shaft 14 . The perforated basket 10 has a screen 15 on its cylindrical inner surface and is contained within a cylindrical outer casing 16 having an outlet pipe 18 at its lower end for leading off liquids centrifugally separated from solids 20 . A pipe 22 enables a wash liquid to be sprayed onto the solids 20 in the basket retained by the screen 15 .
[0009] A measurement of the state of the wash liquid is made at a measurement location 19 in the outlet pipe 18 .
[0010] The flow of wash liquid through the centrifuge—from the stationary wash pipe 22 to the rotating basket 10 , through the solids 20 , basket perforations and screen 15 to flow down the stationary casing 16 inner surface 24 to the casing outlet 18 —is complex. It varies with the liquid viscosities, screen type, basket perforations pattern, casing dimensions, centrifugal speed, windage and outlet position, all of which affect the flow rate. Of concern here is the liquid flow as it leaves the rotating basket and spirals down the inner surface 24 of the casing 16 .
[0011] In an industrial centrifuge, the time period for the wash liquid to reach the outlet pipe from the basket perforations is typically between 5 and 30 seconds. Thus any measurement of the state of the wash liquid immediately after the point of contact with the solids will be delayed by at least this time during which overwashing may have occurred. Thus a flow time of 20 seconds :trom perforations/screen to the outlet to provide a minimum (ideal) solids wash time of 20 seconds requires 40 seconds total wash time and results in a 100% overwashing. These weaknesses are most marked on large centrifuges processing viscous liquids.
[0012] If the flow of the wash liquid is set at a fixed time to ensure a full wash under idealized conditions of maximum process throughput and minimum available wash liquid flow rate, then further overwashing will occur as the process parameters vary from the ideal.
[0013] Overwashing, a weakness of all known existing systems of wash liquid control, is detrimental to the separation process and, depending on the application, may result in one or more of:
[0014] (a) reduced separation efficiency,
[0015] (b) increased process cycle times,
[0016] (c) excess wash liquid usage,
[0017] (d) excess dissolution of solids and
[0018] (e) increased load on secondary effluent separating processes.
[0019] Thus, the present state of the art measuring the liquid condition at the outlet ( 18 ) requires the full flow of the liquid at the outlet pipe measuring point ( 19 ), and gives the required measurement signal only after the liquid has traveled from the perforations/screen to the outlet, a delay ranging from 5 to 30 seconds. Setting a fixed wash time of flow for a correct wash at maximum basket fill level and minimum wash flow rate results in overwashing on all throughputs including the maximum. These weaknesses will be most marked on large centrifuges processing viscous liquids (e.g. in Class X, sugar losses of 10% of the factory sugar output have been recorded by overwashing during centrifuging with fixed time wash control).
SUMMARY OF THE INVENTION
[0020] In accordance with a first aspect of the present invention there is provided an apparatus for the separation of solids and liquids comprising a perforated rotary basket arranged for rotation within a fixed outer casing, a washing liquid supply means for providing washing liquid to the interior of the basket and its contents, and a device for establishing a control signal representative of the state of liquids centrifugally expelled from the basket when such liquids impinge on an inner surface of said fixed outer casing.
[0021] Preferably, the device comprises one or more transducers for monitoring the electrical conductance of liquids flowing thereover in the outer casing, to enable rapid generation of the control signal. Advantageously, said one or more transducers are disposed in or on the inner wall of the outer casing.
[0022] Depending on the dimensions of the transducer or transducers, the control signal can be used either to measure and control the contamination levels of the solids, enabling the solids purity to be set and the contamination level controlled as the process parameters change, or to measure and control the flow of wash liquid flowing in the casing, whereby to enable the termination of the centrifuge separating cycle once the volume of liquid flow reduces to a required level.
[0023] In both cases, overwashing can be eliminated or at least reduced to a minimum using said control signal.
[0024] By arranging for the transducer to measure the liquid conductance substantially immediately and to give the appropriate control signal, the overwashing inherent in the methods presently available can be overcome.
[0025] Some embodiments of the invention may provide appropriate signals as the liquid mix changes to classify the liquids if the centrifuge is being used to separate more than one liquid. An example of this circumstance is the washing and separation of sugar crystals from molasses wherein it is advantageous to pass the bulk of the molasses separated in the early stages of the cycle to one tank and, shortly after the commencement of washing to deflect the combination of molasses and wash liquid flow to another tank.
[0026] Preferably, the transducer comprises at least two electrical conducting strips/shapes (electrodes) separated by a distance by an electrical insulating substance (insulator). A voltage is applied across the electrodes of the transducer establishing an electric current through any liquid flowing down the casing over the surface of the transducer and hence gaining a measure of the conductance of the wash liquid covering the transducer.
[0027] The value of the conductance of the wash liquid may be interpreted in any of a plurality of methods depending upon the dimensions of the transducer, specifically the size of the insulator separating the electrodes and the arrangement and shape of the electrodes and the calibration settings.
[0028] Within the limits set by the transducer dimensions, the relationship between the electrical conductance of the liquid measured and depth of a liquid of constant conductance is for practical purposes proportional to the amount of liquid flowing down the inner casing. This attribute is particularly advantageous when, at the accepted economic minimum flow of the wash liquid, the reduction in centrifuge utilization in continuing the process cycle is greater than the advantage of further liquid separation. At this point the transducer can signal the end of the centrifuge cycle. An example of this situation (hereinafter referred to as Class Z) is in the separation of water from fabrics.
[0029] Within other limits set by the transducer dimensions, the relationship between the measurement of the electrical conductance of the wash liquid and the levels of contamination (organic salts, chloride salts, and other solids conductive in solution) is also, for practical purposes, proportional. This attribute is advantageous in Classes X and Y processes.
[0030] In some embodiments of the invention the transducer comprises at least two electrodes set in an electrically insulating material. If there are more than two electrodes, they can be connected alternately.
[0031] The arrangement of the electrodes may be parallel, trapezoidal, circular or any other patterns as long as an electrically insulating material is between the adjacent electrodes.
[0032] In some embodiments of the invention the electrodes are connected via connections in an electrical circuit using a proprietary alternating current bridge circuit or another form of electronic controller. The electronic controller measures the applied voltage across the electrodes in the transducer and the amount of current flow through the liquid covering the electrodes in the transducer. The electronic controller then generates an output relating to the electrical conductance of the liquid, with facilities to preset the level and range at which the electronic controller generates an output to either control the degree of contamination or the flow of the liquid.
[0033] In some embodiments of the invention, a small auxiliary wash pipe may be attached to clean the surplus liquid off the transducer surfaces and to facilitate calibrations.
[0034] In some embodiments of the invention, a temperature sensing device may be provided to measure the temperature of the liquid and send a signal to the electronic controller to adjust the generated output accordingly.
[0035] In some embodiments of the invention, the electrodes in the transducer may have non-parallel sides to increase the range for which the relationship between the conductance measured via the transducer and the depth of the liquid flowing over the transducer is proportional.
[0036] In some embodiments of the invention, the connections from the transducer to the electronic controller may be re-adjustable externally at the centrifuge to allow the increase or decrease in the amount of electrically insulating material (i.e., alter the values of ‘t’) which has an effect upon the electronic controller's output.
[0037] One feature of this invention is thus to give an immediate signal to limit the wash volume to the minimum needed to achieve the required solids purity that adjusts automatically to the variations in the process parameters. A second feature of some embodiments is to provide a control signal when the solids contamination has been reduced sufficiently so that the centrifuge wash cycle can be terminated. A third feature of some embodiments is to provide a control signal proportional to the volume of liquid (of constant conductivity) flowing through the casing of a centrifuge—the signal terminating the centrifuge separating cycle as soon as the liquid flow reduces to the required level. A fourth feature of some embodiments, when more than one liquid is being separated in a centrifuge, is to give the appropriate signals as the liquid mix changes to classify the liquids. For example in the Class X process for sugar separation it is advantageous to pass the bulk of the molasses separated in the early stages of the cycle to one tank and, shortly after the commencement of washing, to deflect the mixed molasses/wash liquid flow to another tank.
DESCRIPTION OF THE DRAWINGS
[0038] The invention is described further hereinafter, by way of example only, with reference to the accompanying drawings, in which:
[0039] [0039]FIG. 1 is a diagrammatic cross-section through a typical known centrifuge structure to which the present invention may be applied;
[0040] [0040]FIG. 2 is a diagrammatic cross-section of the centrifuge structure of FIG. 1 modified in accordance with a first embodiment of the present invention;
[0041] [0041]FIG. 3 is a diagrammatic front view of a transducer with parallel electrodes, which may be used in accordance within the present invention;
[0042] [0042]FIG. 4 is a sectional view of the transducer of FIG. 3 on the line IV-IV;
[0043] [0043]FIGS. 5 and 6 are diagrammatical representations of transducers with possible regular arrangements of electrodes, which may be used in accordance within the present invention;
[0044] [0044]FIGS. 7, 8 and 9 are diagrammatical representations of possible embodiments of transducers with nonparallel electrodes, which may be used in accordance within the present invention;
[0045] [0045]FIG. 10 is a diagrammatical representation of a possible embodiment of the transducer which allows the operator to alter the effective distance between the electrodes, which may be used in accordance within the present invention;
[0046] [0046]FIG. 11 is a graph which displays experimental results, comparing contamination levels with the electrical conductivity of the wash liquid;
[0047] [0047]FIG. 12 is a graph which displays experimental results comparing the ratio of the depth of the wash liquid divided by the electrode spacing with the electrical conductance of the wash liquid and showing the areas in which the conductance measured is proportional to contamination and, alternatively, proportional to the depth of liquid; and
[0048] [0048]FIG. 13 is a graph which displays experimental results using a transducer with differently shaped electrodes, comparing the ratio of the depth of the wash liquid divided by the electrode spacing with the electrical conductance of the wash liquid and then comparing parallel and non-parallel (angled) electrodes to demonstrate the advantage of angled electrodes in Class Z processes.
DESCRIPTION OF THE INVENTION
[0049] [0049]FIG. 2 shows the centrifuge of FIG. 1 but with a sensor 26 shown at a position on the inner cylindrical wall 24 of the centrifuge casing 16 to provide a control signal on the state of the wash liquid as it impinges on the inner surface of the casing for monitoring and enabling immediate control of the liquid flowing through the centrifuge.
[0050] In the embodiment of FIGS. 2 and 3, the transducer 28 is flush mounted on the inside wall of the casing 16 such as to maintain a near cylindrical inner surface of the casing and to intercept the liquid flow immediately it leaves the basket perforations to measure its conductance. The preferred form of transducer has two or more electrically conductive strips/electrodes 30 set in an electrical insulating substrate 32 and, if more than two, connected alternately, or to a predetermined pattern 34 , as inducted by the dotted lines in FIG. 3.
[0051] The arrangement and shape of the strips can be parallel, trapezoidal, arcuate or any other, pattern so long as the insulated distance “t” exists between adjacent strips.
[0052] In alternative forms of the transducer two or more shapes 37 , which can be rectangular, triangular, arcuate, spiral etc., mounted in a pattern on a substrate with the insulated distance “t” defined between end shape. FIG. 5 shows such a device using triangul(jJ shapes and FIG. 6 with arcuate shapes. The shapes/strips are connected via connections 36 in an electrical circuit using a proprietary A.C. bridge circuit or other electric controller.
[0053] For less viscous liquids, the depth when flowing down the inside of the casing 24 may vary from place to place, with local disturbances in the liquid being created by irregularities in liquid discharge, windage, vibration, etc. A transducer covering too small an area would then give a misleading local value of conductance rather than the required mean or average reading required for liquid depth measurement. To overcome this, the active area of the transducer is set to cover several irregularities so that the conductance measured is the mean value.
[0054] For vertical spindle centrifuges of the type shown in FIG. 2 a rectangular or irregular shaped transducer is used with it's narrow width set circumferentially in the inside of the casing and it's long side set at or near vertical—extending lengthwise over a sufficient portion of the casing height to cover any liquid flow irregularities down the casing. An alternative arrangement of a series of small transducers set one above the other and connected in parallel over an area similar to that of the single rectangular transducer would also give the mean conductance value.
[0055] For horizontal spindle centrifuges, not illustrated, a rectangular transducer would be set with it's long side, as a circumferential arc, around the inside of the casing extending over a sufficient portion of the casing circumference to cover any liquid flow irregularities and with it's narrow side set at or near horizontal. Again, an alternative arrangement with a series of small transducers in the form of an arc and connected in parallel over an area similar to that of the single rectangular transducer would also give the mean conductance value.
[0056] For inclined spindle centrifuges, not illustrated, a combination of the vertical and horizontal arrangements above may be applied, with the preferred arrangement being a single rectangular (or a series of small transducers) set in a spiral arc in the inside of the casing.
[0057] The controller measures the voltage V applied to and current A passing through the liquid flowing down the casing and over the surface of the transducer, with facilities to preset the levels and ranges at which the bridge/electronic circuit operates and gives output signals to control contaminant or liquid flow.
[0058] Using a suitably dimensioned transducer, the value of AIV may be used in Classes X and Y situations to measure and control the degree of contamination of the liquid flowing over the transducer as the electric conductance A 1 V measured at the transducer corresponds to an equivalent contamination level. A typical relationship between conductivity and levels of contamination (organic salts, chloride salts, and other solids conductive in solution), applicable to Classes X and Y, is shown in graph A of FIG. 11.
[0059] In other embodiments, the value of AIV may be used to measure and control the depth of liquid of constant conductivity flowing over a suitably dimensioned transducer (Class Z). An example of a process in which depth measured is advantageous is the termination of liquid flow from a centrifuge. At the accepted minimum flow, the reduction in centrifuge utilization in continuing the process cycle is greater than the advantage of further liquid separation. At this point, the transducer AIV depth signal proportional to the flow of liquid in the machine casing, signals the end of the centrifuge cycle. An example of Class Z is the centrifugal separation of water from fabrics.
[0060] The transducer dimensions, and particularly the spacing “t” between the electrodes, is matched to the application. Generally, the spacing will be closer when used for Classes X and Y and wider for Class Z.
[0061] Returning now to FIGS. 3 and 4, a small auxiliary wash pipe ( 38 ) may be fitted in the casing to clean the surface of the transducer and to recalibrate is as necessary. If the process temperature varies, a temperature sensing device is fitted to measure the wash liquid temperature and, if required, apply a signal to the bridge/electronic controller to adjust the preset conductance levels.
[0062] In another arrangement, the transducer device uses strips or shapes that have non parallel sides so that the insulating substrates separating adjacent strips or shapes are tapered or curved, examples of which are shown in FIGS. 7, 8 and 9 . This increases the range over which “d/t” is near linear as shown by line “g.h.” on Graph C (FIG. 13) which compares the Graph B parallel electrode results with angled electrodes to increase the control range for some Class Z applications.
[0063] In an alternative embodiment of the invention the connections from the transducer to the electronic controller may be re-adjustable externally at the centrifuge to allow the increase/decrease in the amount of electrically insulating material (i.e., alter the values of “t”) which has an effect upon the electronic controller's output, as generally indicated in FIG. 10 which shows alternative connections for operating at electrode spacings of “t” and “T”.
[0064] The graphs of FIGS. 11, 12 and 13 show various experimental results applicable to the present invention.
[0065] Graph A of FIG. 11 shows a typical relationship between the conductivity of the wash liquid and the level of contaminates (organic salts, chloride salts, and other solids conducive in a solution) in the wash liquid.
[0066] A series of experimental results is given in Graph B of FIG. 12 showing for parallel electrodes the relationship between the electrical conductance measured via the transducer and the ratio of liquid depth “d” flowing over the transducer divided by the electrode spacing “t” for various contamination levels. This indicates that for values of “d/t” from zero to one the relationship between liquid depth and the electrical conductance measured via the transducer is for practical purposes linear (as indicated by line ab.) In these circumstances the transducer signal is proportional to the thickness of the wash liquid flowing over the transducer and therefore proportional to the quantity of liquid flowing down the inner casing. An electrode spacing “t” greater than the value of “d” that corresponds to this maximum flow rate may be used; typically two to five times “d”.
[0067] The experimental results in Graph B also show that for values of “d/t” greater than four the conductance measured via the transducer is independent of the liquid depth and proportional to the level of contamination only (as indicated by line ef.) The electrode spacing “t” used may be less than a quarter of the minimum value of “d”, typically 0.2 to 0.05 times “d”.
[0068] Graph C of FIG. 13 demonstrates that it is possible to increase the control range for some applications by implementing electrodes which have nonparallel sides such that the insulating substrate separating adjacent strips or shapes are tapered or curved (examples of which are shown in FIGS. 7, 8 and 9 ). The range over which “d/t” is near linear as shown by line gh compares favorably with the results taken from Graph B where the electrodes are parallel, hence demonstrating the increase in the control range for Class Z applications.
[0069] Thus, the present invention, used as described above, in one form makes a near instantaneous measure of the condition of solids rotating in a centrifuge and, when the required condition is reached, signals the process to proceed without overwashing losses and without delay. In another form the apparatus signals the optimum minimum level of liquid flow from a centrifuge for the process to proceed immediately. Both forms compensate automatically for changing process parameters, avoiding the need for manual intervention to adjust for process parameter changes.
[0070] Thus, an apparatus in accordance with the invention can be free of the limitations inherent in the state of the art methods of overwashing and applies to all methods of using the transducer as described herein to control liquid flows.
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An apparatus for the separation of solids and liquids includes a perforated rotary basket arranged for rotation within a fixed outer casing, a washing liquid supply system for providing washing liquid to the interior of the basket and its contents, and a transducer device for establishing a control signal representative of the state of liquids centrifugally expelled from the basket when such liquids impinge on an inner surface of the fixed outer casing. The transducer is set in or on the inner wall of the outer casing for monitoring the conductance of liquids within.
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This is a continuation of application Ser. No. 06/937,298, filed Dec. 3, 1986, which was abandoned upon the filing hereof.
BACKGROUND OF THE INVENTION
The invention relates to a process for the production of irregular non-woven material sheets which are drawn off in the form of a warp from spinnerets by means of a gaseous propellant generated by a compressor or the like and are deposited on a substrate. Furthermore, the invention relates to an apparatus for carrying out the process.
processes and apparatus of the above presupposed species are already known from German patent 1 785 158, British patent 1 282 176 and British patent 1 297 582. A common characteristic of these processes is that the warp is drawn off the spinnerets under the influence of compressed air by means of a filament draw-off device and, after passing through a spreading device, is deposited on the substrate in order to form an irregular non-woven material sheet.
An important aspect during the production of non-woven material sheets is the filament draw-off force occurring in the filament draw-off device which, in the known processes and apparatus, is mainly created inside a filament offlet having at its upper end a filament draw-off nozzle supplied with highly compressed air.
In practical use it has been shown that, although a sufficient filament draw-off force can be generated with the filament offlets, the filament offlets have, however, a disadvantage in another way. It is possible that within the narrow filament offlets--the inner diameter is, for example--around 3 mm--the individual filaments can become tangled, which has the troublesome result that the structure of the irregular non-woven material sheets is not uniform. However a definite characteristic of the quality of an irregular non-woven material sheet is as uniform a structure as possible.
This is where the invention comes into play, by means of which a process and an apparatus is to be created which permit the production of irregular non-woven material sheets with as uniform a structure as possible.
SUMMARY OF THE INVENTION
To achieve its goals, the invention takes an entirely novel approach leading away from the customarily used filament offlets and, instead, making it possible to draw off and guide the warp along a wall area or nozzle wall composed of several slot nozzles. Since this way no bundling takes place within the filament offlets, the danger of tangling of several filaments has been removed, so that irregular non-woven material sheets with a uniform structure can be made.
The invention is based on the realization proven by tests, that the necessary filament draw-off forces of approximately 0.2N (measured for comparison purposes on a copper wire of 0.12 mm diameter) can be created with several stacked slot nozzles. In this regard a disposition, in which the air exits the slot nozzles at an angle of approximately 15° or less--in relation to the direction of the movement of the filaments--has been proven practical, creating a strong power component acting as drawing force in the direction of the movement of the filaments.
A further important characteristic of the invention consists in the novel utilization of an adiabatic or polytropic process, while the known processes operate isothermically. The invention proceeds from the realization, mathematically derived further on, that in an adiabatic process (among other reasons because of the higher viscosity of the air at higher temperatures) higher filament draw-off forces can be achieved than in the isothermic process, which is an advantage in the sense of the efficiency of the novel process. In contrast to the isothermal process, no condensation moisture is created, for which reason the sticking together of the warps is advantageously avoided.
In a practical embodiment of the invention the admission pressure of the slot nozzles is set somewhat higher than the critical pressure (the ratio of the admission pressure to the ambient pressure therefore is greater than the Laval pressure ratio). The expansion of the air stream occurring at the exit of the slot nozzles advantageously lifts the warp manner by a small amount from the flat nozzle wall so that in this respect there is also no danger of tangling or sticking to the nozzle wall.
In accordance with the thermodynamic laws the compressed air heats up to more than 350 K, and during the expansion at the exit of the slot nozzle approximately ambient room temperature is reached again, while the slot nozzle itself heats up considerably, possibly leading to a danger of the filaments sticking to the nozzle wall. For this reason, cooling in the front part of the slot nozzles is provided in a practical embodiment of the invention in the form of bores through which, for example, water is pumped.
Although a process for the production of an irregular non-woven material sheet of synthetic filaments guided along a wall is known from German laid-open publication DE-OS 1 760 713, only one slot nozzle serving as draw-off device is provided there. In an expensive and disadvantageous manner, special spacers are provided to keep the warp at a distance from the walls and, furthermore, no adiabatic or polytropic process is provided in the known method. Finally, the working of this known process requires an additional adjustable plate located opposite the wall, which leads to extra expense.
Furthermore, in Swiss published publication CH-DS 405 220 there is already described a method for producing flat fiber bodies where warps are guided through assigned closed channels which are used for guidance and cooling of the warps, while the actual filament draw-off forces are created by two slots supplied with air and located immediately below the spinneret. Within the channnels secondary air is introduced via obliquely disposed slots, so that the several warps are completely solidified after leaving the assigned channels and can be deposited in turn, by which a multi-surface filament body is created. So that, if possible, all filaments can be captured by the air flow, the spinnerets are shaped comparatively narrow, so that the production rate of the known process is correspondingly small. The use of an adiabatic or polytropic process is not mentioned there.
In order to further increase the desired uniform structure of the irregular non-woven material sheet of the invention, a so-called flip-flop cross winding has been provided in a practical embodiment, known per se from German patent 24 21 401, which guarantees an especially great uniformity of the structure in combination with the novel nozzle wall.
Further advantageous improvements of the invention are disclosed in the sub-claims and are shown in the drawings.
The invention is further explained below by means of the exemplary embodiments shown in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross-sectional view to show the principle of an apparatus according to the invention,
FIG. 2 is a diagram showing the filament draw-off forces,
FIG. 3 is a cross-sectional view of a slot nozzle with a supply tube,
FIG. 4 shows the different slot widths of a slot in a supply tube,
FIG. 5 is a cross-sectional view along the section line A--A of FIG. 3,
FIG. 6 is a cross-sectional view along the section line B--B of FIG. 3, and
FIG. 7 is a cross-sectional view along the section line C--C of FIG. 3.
DETAILED DESCRIPTION
In FIG. 1, synthetic filaments 12 are drawn off spinnerets in the form of a warp 10 by means of a downwardly directed stream of air, which is generated by slot nozzles 16 stacked atop each other, forming a wall of nozzles 18. By means of a transverse stream of air, indicated by arrows B, the filaments 12 exiting from the spinnerets are cooled to room temperature and the filaments 12 are aligned by a horizontally adjustable tube 14.
By means of an air compressor, not shown, which is operated adiabatically or polytropically--for example, a single stage turbo compressor--air reaches the nozzle chamber 24 via the feed 22. The exit slots 26 of the slot nozzles extend at an angle of about 15°, so that a downwardly directed air flow is created into which the aligned filaments 12 dip at the angle mentioned.
The air exiting at the speed of sound exerts a pulling force having an exactly determined value in order to achieve the desired filament titre on the filaments 12. By means of a test arrangement with a copper wire of 0.12 mm diameter it was possible to measure and determine that for the production of a polypropylene non-woven material (pp) with a filament titre of 2 dtex (1 dtex=thickness of a filament of a weight of 1 g and a length of 10,000 m) a draw-off force of 0.2N is required
The results of the measuring are shown in FIG. 2--together with a schematic arrangement of the test lay-out--. As can be seen, the filament draw-off force of 0.2N can be achieved easily with thirty stacked slot nozzles, while with the use of only one slot nozzle a sufficient filament draw-off force could not be achieved, even when increasing the compressed air pressure.
The compressor as well as the slot nozzles 16 are operated polytropically. The compressor compresses the air from the ambient state polytropically to or higher than the critical pressure of 1.894 bar. In order to achieve as complete a use of the energy as well as the adiabatic process, the compressor, the supply lines and the backs of the slot nozzles are insulated.
Although the compressed air has reached a relatively high temperature of to more than 350 K, approximately room temperature is reached again at the exit of the slot nozzles 16 when the air is expanded and the pressure of the air decreased, but the slot nozzles 16 heat up so that there can be danger of the filaments 12 sticking to the nozzle wall 18. For this reason bores 20 for water cooling are provided at the front end of the slot nozzles 16 in order to draw off the heat.
After passing the nozzle wall 18, i.e. the slot nozzles 16, the filaments reach a spreading device 28 and are then deposited on a screen conveyor 30 in the form of a uniformly distributed non-woven material sheet. The spreading device 28 comprises two spaced apart oscillating Coanda shells 32 and is further described in German patent 24 21 401, so that there is no need to further discuss this here.
For a better understanding of the novel process based on an adiabatic process and the effect thereof on the filament draw-off force, the appropriate mathematical relationships are further discussed below. It is known (Mayer, "Berechnung der Schubspannung und Warmeubergang an langsangestromten Faden", Chem-Ing.-Technik, 42. Jahrgang 1970, Nr. 6, Seite 401; Hamana et al "Der Verlauf der Fadenbildung beim Fadenspinnen", Melliland Textilberichte 4/1969, Seite 384)[Mayer, "Calculation of propellant Tension and Heat Transfer on Filaments Longitudinally Blown Against", Chem-Ing.-Technik. Vol. 42, 1970, No. 6, p. 401; Hamana et al "The Development of Filament Generation during Filament Spinning", Melliland Textile Reports, 4/1969, p. 384] to define the resistance coefficient c of a moving filament in static air according to the equation ##EQU1## where τ is the wall propellant tension at a filament element of a length dx, γ=1/v the specific weight of the air and w the air speed (filament) and d denotes the filament diameter.
The resistance coefficient c is not a constant; it changes according to the equation
c=a·Re.sup.-b (3)
with the Reynolds number Re. The constants a and b shown in the above equation differ depending on the author and in Mayer are a=0.14; b=0.726; in Hamana a=0.37; b=0.61 and in Thompson a=1.13; b=0.60.
With the Reynolds number ##EQU2##
where υ is the kinematic viscosity and η the dynamic viscosity, when equating the above equations (1) and (3) with the constant of Hamana, the result for the filament draw-off force is: ##EQU3##
in the above should be inserted: d in m; v in m 3 /kg; w in m/s and η in kg s/m 2 .
Based on the above equation (6) the following now results in general for the filament draw-off force: ##EQU4##
where in accordance with the calculation method of Hamana the value 0.61 and according to Hayer the value 0.726 should be inserted for b. In a comparison between adiabatic and isothermal line performed according to both methods of calculation (Hamana and Mayer), the values for the critical state at the slot nozzle exit are to be inserted for d, v and η. In the following the corresponding quantities for the adiabatic line and, in parentheses, for the isothermal line are stated: w k =342.9 (313.0) m/s; v k =0.855 (0.712) m 3 /kg; T k =293 (244) K; η=1.855.10 (1.598·10 -6 ) kg s/m 2 .
According to Hamana: p f =1.133 (0.978) applies, and according to Mayer: p f =0.1222 (0.1027).
As a result of this comparison according to both calculation methods it should be noted that the adiabatically operated slot nozzle generates a filament draw-off force higher by approximately 15%. In this lies an important advantage of the novel process, because the cited result means, drawing the reverse conclusion, that less energy is needed to achieve a certain filament draw-off force with the adiabatic process than with the isothermal process, which makes possible a considerable energy savings.
The fact that the air compressor as well as the slot nozzles are operated adiabatically or polytropically leads to the other advantage that no condensation moisture is created as is in the isothermal process and that therefore the sticking together of the warps can be avoided.
It had been already noted above that the admission pressure of the slot nozzles 16 is set somewhat higher than the critical pressure, so that the expansion of the air stream occuring because of this at the exit slots 26 of the slot nozzles 16 lifts the warps slightly away from the nozzle wall 18.
However, the admission pressure is not set too high, but is kept as low as possible within the scope of practicality, since the ratio of energy expenditure to filament draw-off power is more advantageous at low nozzle admission pressure. The lower limit of the admission pressure occurs when the relative speed between the filaments 12 and the air is so small that the filament draw-off force decreases out of proportion. A preferred value of the ratio of energy expenditure to filament draw-off force lies between 1.1 and 5 bar.
The detailed construction of a slot nozzle 16 used with the novel process and in the novel apparatus can be seen from FIGS. 3 to 7. Each slot nozzle 16 has a front chamber 34 and a rear chamber 36, which are connected with each other via a slit 42 of 1.5 mm. The front chamber 34 leads via a slit 38 (1.5 mm) into the exit slot 26. Ribs 40 in the form of a flow grating are disposed in the feed to the exit slot 26 in order to align the turbulent flow ahead of the exit slot 26. In the front section of the slot nozzle 16, bores 20 for cooling by means of cooling water or the like are provided, as can be seen especially clearly in FIG. 3 Within the rear chamber 36 a supply tube 44 extends in each slot nozzle 16, the two outer ends of which are connected to the compressor, not shown, i.e. supply of air comes from the direction of both ends of the supply tube 44.
The wall of the supply tube 44 extends near the upper and lower wall of the rear chamber 36, forming a slit 48 and 50 of approximately 1.5 mm each.
The supply tube 44 has a slot 46 from which the air from the compressor can exit into the rear chamber 36. The slot 46 extends along the entire length of the rear chamber 36 and has different slot widths over this length, as schematically shown in FIG. 4. For the purpose of averaging out over the entire width of the slot nozzle, the width of the slot has been changed symmetrically to the center of the tube (seen in a longitudinal direction). In the center of the tube the slot width S is 2 mm and it is discretely enlarged up to 3 and 4 mm in the direction to the tube ends. In actuality the diameter spread is equalized, so that the slot 46 widens continuously from 2 mm at the center to 4 mm at the ends.
The innovation associated with the invention is not limited to the exemplary embodiment described, many modification are possible within the scope of the invention. The main object always is the idea to guide the filaments 12 not through tubes, but along a flat wall surface, namely the nozzle wall 18, while achieving the filament draw-off force, in order to avoid tangling of the several filaments 12 and thereby to guarantee a uniform distribution of weight over the surface of the irregular non-woven fabric sheets to be produced.
In connection with FIG. 3, it should additionally be pointed out that in actuality a slightly tapering nozzle lip is probably hard to manufacture with machine tools. To remedy this, a glued-on wiper sheet 54 is used in a practical embodiment of the invention which meets in a simple and precise manner the requirements demanded.
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In the production of irregular non-woven material sheets of synthetic filaments, the warp from spinnerets is drawn off by means of a draw-off device and then deposited on a substrate. To avoid tangling of the individual filaments, they are guided along a nozzle wall formed by slot nozzles stacked on top of each other and forming a draw-off device. The slot nozzles as well as the air compressor are operated polytropically. The deposit of the warp on the substrate is accomplished by a flip-flop cross winding.
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This is a continuation of application Ser. No. 07/873,844 filed Apr. 27, 1992, now U.S. Pat. No. 5,249,410.
FIELD OF THE INVENTION
This invention relates to a device which may be used to seal food into open-topped containers, to a method of sealing such containers and to a specific type of open-topped container. In particular, this invention relates to a device suitable for heat shrinking film onto such open-topped containers to seal food or drink inside the container.
BACKGROUND OF THE INVENTION
Presently in the fast food drink industry it is typical to serve a drink in a paper, plastic or other disposable cup topped with a preformed plastic lid. The plastic lid fits tightly over the lip formed at the top of, for example, a paper drink cup, and may include apertures to permit straws or openings to be formed in the lid to directly drink the contents of the cup.
Unfortunately, there are many problems associated with the use of these plastic lids. For example, the lids are generally expensive. Further, the lids are bulky and create problems in storage and in disposal. Further, the seal formed by the lids is dependant upon the lid being placed on properly, and can leak if not properly placed. Finally, the handling of the lid is not completely hygienic.
In order to overcome these problems, various devices and methods have been proposed in which a cover is placed on an open-topped container and then heated to shrink it into sealing engagement with the top of such a container. Examples of such devices can be found in the following United States patents: U.S. Pat. Nos. 3,260,775; 3,354,604; 3,460,317 3,491,510; 3,494,098; 3,507,093; 3,621,637; 3,877,200; 3,838,550; 3,916,602; 4,035,987; 4,184,310 and 4,562,688. While the solutions proposed by these prior devices and methods are interesting, they fail to provide a sufficiently cost efficient, easy and inexpensive alternative to preformed rigid plastic lids. As a consequence, rigid plastic lids remain in widespread use. Some of the main failings of these prior devices are that they are bulky, noisy, unresponsive, and expensive. Heating systems comprising blowing air over a hot element and then onto a film require large amounts of unnecessary heat, even when in standby mode, which makes temperature control very difficult. Further, continuous elevated temperatures are expensive to maintain and may be deleterious to the immediate environment.
SUMMARY OF THE INVENTION
Aside from the benefits of increased hygiene and reduced waste, the present invention is directed to providing a practical device which has commercial utility. One aspect of the present device is to provide an energy efficient way of sealing open-topped containers which avoids any substantial build-up of heat. An intermittent source of radiant energy is used, and energy is directed onto an energy absorber located at the specific place where heat is required. Thus, heat is originated where it is needed, when it is needed and a cooler, quieter, safer and more efficient device results.
The present invention provides a device for heat shrinking a cover onto an open-topped container, said device comprising:
a housing adapted to receive said container; and having a strip of heat shrinkable thin film;
a cutting means positioned against said thin film for cutting said thin film upon said thin film being urged onto said cutting means by said container;
a hood for holding a cut piece of said film in place across said open top of said container, wherein said cut piece includes a portion extending from under said hood downwardly around an upper outer rim of said container;
a first radiant energy source for directing energy toward said downwardly extending portion of said cut piece of film;
a first means to absorb radiant energy to transfer heat to said downwardly extending portion of said cut piece of film; and
a switch means for intermittently energizing said first radiant energy source whereby said downwardly extending portion of said cut piece of film is shrunk onto said rim;
The present invention also provides for a container for receiving heat shrinking film to form a spill-resistant cover comprising an open-topped container having a circumferential darkened band around said container, said darkened band having an elevated rate of absorption of radiant energy over and above the rate of absorption of said container.
In a further embodiment the present invention provides a method of forming a spill-resistant cover on a container having an open top, the method comprising placing a heat shrinkable thin film over the open top of said container, and subjecting said container and said thin film to a source of radiant energy wherein said radiant energy causes said thin film to shrink and form a spill-resistant cover over said open top of said container.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a device according to the present invention in use;
FIG. 2 is a front sectional view of an open-topped container according to the present invention with a heat shrunk cover in place;
FIG. 2a is a top view of the container of FIG. 2.
FIG. 3 is a front view of the container of FIG. 2 having a darkened upper band;
FIG. 4 is a top view of the device of FIG. 1, with the top wall broken away to show the contents;
FIG. 5 is a sectional view taken along lines 5--5 of FIG. 4;
FIG. 6 is a view similar to FIG. 5 with the container in a raised position;
FIG. 7 is a view of a part of the device of FIG. 1; and
FIG. 8 is a view along lines 8--8 of FIG. 7;
FIG. 9 is an alternate configuration for a knife element shown in FIG. 5;
FIG. 10 is a view along lines 10--10 of FIG. 9;
FIG. 11 is a schematic sketch of an electronic control circuit for the present invention;
FIG. 12 is an alternate embodiment of a microswitch system according to the present invention;
FIG. 13a is a view along lines 13--13 of FIG. 12 in a first position; and
FIG. 13b is a view along lines 13--13 of FIG. 12 in a second position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a device 10 for heat shrinking a thin film onto an open-topped container 12. The housing 10 includes an opening 14 of sufficient size to allow placement of the container 12 within the housing 10. In the embodiment of FIG. 1, placement of the container 12 within the opening 14 is accomplished manually, illustrated by a hand 16.
Turning to FIG. 5, there is shown a cross-sectional schematic view of the operational components of the device 10 of FIG. 1. The container 12 is shown in the opening 14. The opening 14 is defined by side walls 18 and 20 of the device 10. Shown on the right-hand side is a roll of thin plastic film 22 on an axle 24. The film 26 passes over a roller 28 across the top of the container 12 across a second roller 30 and onto a take-up axle 32. Shown at 34 is a rewind motor. It will be appreciated that the rewind motor 34 can rotate the pick-up axle 32 in the direction of arrow 36 which will advance the film 26 across the top of the container 12 and cause the roll of film 22 to rotate in the direction of arrow 38. Alternatively, the advancing of the film 26 could be accomplished manually by turning a lever or knob mounted on take-up axle 32.
The film 26 is preferably a bi-axially oriented shrink film having a preferred thickness of between 40 to 120 gauge with the most preferred being between 60 to 100 gauge. Good results have been achieved with a 75 gauge polyvinyl chloride film purchased from Reynolds Metals Company at Richmond, Va. Other films, such as copolymers, polyolefins and the like may also be appropriate. The film, to be most useful, must be foodgrade contact-approved by the appropriate regulatory authorities. A 71/2" outer diameter roll of 75 gauge shrink film, which includes a 3" diameter fibre core, will yield approximately 8,000 covers according to the present invention.
In FIG. 5, the container 12 is located in a locator identified generally at 40. The locator 40 is shown in more detail in FIGS. 7 and 8. Turning to FIG. 7, there is shown a plate 42 having a pair opposed guides 44 and 46. The plate 42 also has an opening 48 located between the guides 44, 46. The guides 44 and 46 are substantially identical and therefore the following discussion in respect of guide 44 applies equally to guide 46.
The guide 44 comprises a rub rail 50 which contacts an outer edge of a container 12. Extending from plate 42 are two posts in respect of each guide 44, 46. In respect of guide 44 there is a stop post 52 and a guide post 54. A slot 56 is formed in the guide 44 and a spring 58 is housed between the guide post 54 and the end of the slot 56. A pin 59 may be used to secure one end of the spring 58. A washer 60 is used to retain the other end of the spring 58 within the slot 56. The washer 60 is placed around the guide post 54. Between the free end 55 of guide post 54 and the washer 60 is a further spring 61. The spring 61 allows the guide plate 44 to articulate away from the plate 42 to facilitate removal of the container 12 from the device 10.
It will now be appreciated that the guide 44 can move laterally in the direction of double ended arrow 62 guided by means of the stop 52 and the guide post 54 with the slot 56. It will also be appreciated that the curved portion 64 of the rub rail 50 will provide an indication to anyone inserting a container 12 into the locator that the container is appropriately located. Appropriately in this sense means centered under the plate opening 48.
Turning to FIG. 8, the locator 40 of FIG. 7 is shown in cross-sectional view. As can be seen, the guides 44 and 46 are positioned on adjacent side edges of a container 12. The plate opening 48 is shown together with the plate 42. The thin film 26 is also shown stretched across the top 13 of the container 12.
It can now be appreciated that the container 12 can be moved in the direction of double ended arrow 65 into position beneath plate opening 48. During this period, the guides 44 and 46 will gradually open and then close about the periphery of the container 12. Thereafter, as shown in FIG. 8, the container 12 is free to be moved in the direction of double ended arrows 66 as will be discussed below. It will be appreciated that containers 12 of varying diameter can thus be accommodated by the instant invention, since all containers will be centered by the locator beneath the plate opening 48. This is desirable in a food services environment where cup size selections typically include small, medium and large.
Turning now to FIG. 5, a container 12 is shown centered in locator 40. A first radiant energy source 68 and a second radiant heater 70 can now be explained. Located above the centered and located container 12 is a top shrink hood 72. The second radiant heater 70 is located within the top shrink hood 72. The top shrink hood 72 includes a glass shield 74 and a heat transfer means 76. In some circumstances the glass shield 74 may not be required, however, to prevent the possibility of splashes reaching the second radiant energy source 70, it is preferred. It may not be necessary to use glass. Plastic or other transparent substances may be appropriate. Good results have been achieved when the heat transfer means 76 is made from a screen aluminum material painted a dark colour, such as black. The dark aluminum heats and cools quickly which is desirable in the circumstances.
A pierce tool 78 is also shown extending outwardly from the heat transfer means 76. The purpose of the pierce tool 78 is to make a vent opening in the thin film to allow gases such as carbon dioxide from a soft drink to escape the container.
An alternative to pierce tool 78 is to form small opaque portions 79 in the shrink film. These opaque portions or "dots" will cause a hot point which may perforate the film as more fully explained below. If desired the hot points can be made in a specified pattern to form a sipping opening or the like, as shown in FIG. 2A. Also shown in FIG. 2 is a straw 122 with a pointed end 124 for piercing the film, shown in place as 126. A fluid, such as a soft drink is shown at 128.
Also shown in FIG. 5 is a drive belt 80 which connects a pulley 82 with a motor. Attached to the pulley 82 are a pair of arms 84. The arms 84 rotate when the pulley 82 is rotated by the belt 80. Depending from the arms 84 about pivot points 86 are pivot arms 88. Pivot arms 88 include a roller 90 at one end and the first radiant energy source 68 at the other end. If preferred, a reflector may be provided such as 92 around the first radiant energy source 68.
Also show in FIG. 5 is a knife or film cutting blade 94 to which is attached a heating element 96. The heated blade 94 ensures a quick clean cut of the thin film, upon the thin film contacting the blade 94. As can be seen from FIG. 5, the blade 94 is below the top hood 72, so the film will be cut to shape just prior to or about the same time as the container 12 contacts the hood 72. Good results have been achieved when the blade is made from a two point center face steel cutting rule, and maintained at a temperature of between 275° F. to 400° F. This format appears to limit smoke and fume generation.
The knife 94 may be circular in shape to provide a symmetrical overhang for a circular container, or may be as shown in FIGS. 9 and 10. It will be noted that the knife 94 in FIGS. 9 and 10 includes a rounded oblong section 95. This will result in a similarly shaped section being formed in a cut piece of film, as described below, which can be used as a convenient pull tab for removing a cover which has been shrunk onto a container 12. In the preferred embodiment the thin film 26 has a width greater than the width of the knife 94 so that a trim 27 (see FIG. 5) is left after the cut is made, and the trim 27 is strong enough to allow the film 26 to be advanced by a tensile force without tearing.
Turning now to FIG. 6, the operation of an instant device can now be understood. In FIG. 6 the container 12 has been raised in the direction of arrow 100. This has had the effect of pushing the film 26 upwardly into engagement with the knife heated film cutter blade 94. This has caused a cut portion of the film shown as 102 to be draped across the top 13 of the container 12. At this point the hood 72 is holding the cut piece of film 102 generally in place. As the container 12 is raised further, the hood 72 is also raised. Rollers 90 then contact a ledge 104 formed on the outer surface of the hood 72. Further upward movement causes the movement of the first radiant energy source 68 about the pivot point 86 until the first radiant energy source 68 is closely adjacent to a draped over edge of cut portion 102 shown as 103. Contact is then made at a limit switch, as explained below in respect of FIG. 11, which energizes a motor 99 (shown in FIG. 4). Upon energization of the motor 99, the belt 80 revolves causing the rotating arms 84 to revolve rotating the first radiant energy source 68 about the periphery of the top of the container 13. Simultaneously with the energization of the motor 99 and the rotation of the first radiant energy source 68, the first radiant energy source 68 is energized to cause radiant energy to be directed towards the dangling edge 103 of the cut portion 102 of the said film 26.
It will be appreciated that the preferred invention causes the first radiant energy source 68 to move into position closely adjacent the downward edge 103 of the cut portion 102. Such movement is preferred because radiant energy obeys the inverse squared rule in which the amount of energy is proportional to an inverse of the square of the distance from the source. By locating the first radiant energy source 68 close prior to being energized, more energy can be usefully used and focused away, for example, from an operator's hands. Also, by the pivoting action, the operator's hands are kept clear of the energy source 68, until the container 12 is in position.
After a predetermined length of time, the first radiant energy source 68 is de-energized and the second radiant energy source 70 is energized by a timer as described in more detail below. The second radiant energy source 70 energy is directed through the glass shield 74 onto an energy absorbing body 76. This transfer of heat causes a shrinking of the top portion across container 12 of the cut portion 102. Thereafter, the sealed container 12 can be lowered and removed from the apparatus.
A preferred type of energy absorbing body 76 is a darkened aluminum screen. The body 76 is placed very closely adjacent the top portion of the cut section 102 and may be in contact therewith. The darkened screen or body 76 absorbs energy and transfers it onto the top portion. It will be appreciated that aluminum is a suitable material because it will cool rapidly, when the energy source 70 is shut off, thereby preventing premature shrinkage of a top portion on a subsequent container upon being first introduced into the hood 20.
It has been found that the preferred radiant energy sources are Tungsten Halogen Lamps. About 70% of the energy produced by these lamps is in the preferred wavelength range of the infrared (750 millimicrons and beyond).
These lamps are compact, durable, inexpensive and readily available. Lamps in the range of 200 to 300 watts are suitable. It will be appreciated by those skilled in the art that other energy sources which produce sufficient infrared radiant energy may also be used.
It is also to be noted that the radiant energy emitted by such an energy source can be turned on and off instantaneously and focused and directed to the location it is desired, without stray heat energy being produced, and the energy source does not have to be on continuously, or on standby in readiness for a container, which is the case of prior art hot air systems.
Turning now to FIG. 4, the belt 80, pulley 82 and drive motor 99 are all shown. Also are shown two rotating arms 84 and two first radiant heaters 68. It will be appreciated by those skilled in the art that fewer or more radiant heating elements could be used according to space requirements and preference. However, when the drive motor operates at 100 rpm, two radiant heat means 68 provides good results. By varying the size of the pulley 82, the speed of revolution of the first radiant energy source 68 can also be varied. Good results have been achieved when the pully 82 is configured to cause the first radiant energy source 68 to rotate at 100 rpm.
It will also be appreciated that the spinning first radiant energy source 68 could be replaced with a row of fixed position bulbs. However, the process would be slightly more difficult to control, since the total energy output would likely be greater, and more energy expensive. Thus, the moving first energy source 68 is preferred.
Turning to FIG. 11, a schematic of an electrical system 150 for the instant invention is disclosed, which sets out in more detail the interaction between the container 12 and hood 72 location, and the activation of the various components described above.
One of the characteristics of the electrical design is that it must compensate for the varying rates that the container 12, which is moved by a human hand, enters and leaves the device 10.
In the preferred embodiment the raising and lowering of hood 72 and the motion of locator 40 will trigger micro-switches which engage timers as described below. Certain events must take place as hood 72 is raised and other events must take place when hood 72 is lowered.
Referring to the wiring system 150, F1 is a fuse. When the main switch 170 is turned on, a pilot light R lights up. Then, switches S1 and S2 are manually turned on. As shown, S1 turns on resistance heater 96, which heat the knife 94. A thermostatic control is shown at 97. When S2 is turned on, it activates motor 99 and also signals timer T1. Also shown is a relay TM-1. The timer T1 engages motor 34 and advances the film 26 for a single "space", which is determined by the time set on timer T1. Thus when the machine is activated and ready to operate by turning on switch S2, a fresh piece of film 26 is automatically presented. Switch LS1 is situated on plate 42, (shown in ghost outline in FIG. 7) so that when guide 46 rotates outwardly on withdrawal of the container, LS1 also signals timer T1 which engages motor 34 and advances the film in a like manner.
Also shown are switches LS2 and LS3 which close when hood 72 moves upward. These switches activate a second timer T2 which activates relay TM-2 which in turn activates first radiant energy source 68. On the downward motion switch LS3 opens and thereby prevents timer T2 from activating source 68 again.
On the downward motion of hood 72, switch LS4 closes, which activates timer T3 which through a relay TM-3, activates radiant energy source 70 for a predetermined time.
FIG. 12 shows in schematic form the microswitch interconnections. On the left hand side of FIG. 12 are the belt 80 around the pulley 82. A shaft 200 extends upwardly from the top hood 72. A connecting rod 202 is attached to shaft 200, and will rise and subside with the hood 72 being raised and lowered. Remote from shaft 200 there is a rack 204 connected to the rod 202 which interacts with a pinion 206, in a manner shown by double ended arrows 208. Also shown are a cam shaft 210 attached to eccentric cams 212.
Shown in FIGS. 13A and 13B are the means of closing electrical circuits upon rotation of the cam shaft 210 by the pinion 206. A secondary roller 214 is located on a pivot arm 216. When cam 212 is rotated in one direction an electrical spring clip 218 is forced into contact with an electrical contact 220 closing a circuit. Upon being rotated in an opposite direction, the cam 212 urges the pivot arm 216 up and out of the way, and does not close the circuit, as shown in FIG. 13B.
It can now be appreciated that the present invention uses radiant energy from the radiant energy sources to effect shrinkage. Radiant energy is preferred, because it travels relatively unimpeded through transparent mediums such as air or transparent film. The preferred radiant energy source is a Tungsten-Halogen bulb, which is described in more detail above. The present invention has process parameters for heating which depend upon an absorbing means for the radiant energy, and in particular, how close any absorbing means conforms to a theoretically ideal "black body". An ideal "black body" completely absorbs all radiant energy that strikes it and thus is capable of radiating that same energy outward.
The way in which the present invention seals heat shrinkable thin film onto a container, is to employ a first means to transfer heat to the downwardly extending portion of the cut piece of thin film. In this sense, the first means can comprise adapting the thin film to absorb energy, interposing an absorbent body adjacent to thin film, or adapting the area of the container just below the rim to become energy absorbing. The thin film can be adapted to absorb energy by being made from a tinted material, or by being coated with an energy absorbent coating, for example, printing. The ability of the opaque or coated film to absorb radiant energy will vary depending upon what type of tinting or coating is used. A darker or more opaque film will absorb more energy.
An example of a preferred interposed absorbent body is a darkened aluminum screen 112, which moves closely adjacent the edge 103. The darkened portion of the screen will absorb energy and then radiate it, giving rise to heat. The heat will be transferred to the air adjacent to the film, then to the film which will shrink the film.
The container may be adapted to absorb radiant energy, and thus produce heat in a preferred location, by including a darkened band 15 in the area where heat generation is desired, such as just below the rim. For aesthetic reasons, black bands may not be acceptable, but other coloured bands will also work. With a cooler colour, the exposure to the radiant energy source may need to be slightly longer. However, the length of time of exposure to the radiant energy source can be adjusted in the present invention through adjustments made to the timer T2. A gap 17 may be incorporated into the band 15 to permit the end user to lift the shrunken cover off the container if so desired.
In some circumstances, it may be desirable to urge the film onto the cup. Therefore, the present invention also comprehends the use of a spring wire 110, which trails (or leads) the revolving first radiant heat means 68, and urges the edge 103 into contact with the container 12 just below the top 13.
It will be appreciated by those skilled in the art that the foregoing description relates to a preferred embodiment and that various modifications can be made without departing from the broad scope of the appended claims. Some of these modifications have been discussed above and others will be apparent to those skilled in the art.
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A device for heat shrinking thin film onto open-topped containers to form spill-resistant covers is shown. A radiant energy source is intermittently energized in association with timers to direct radiant energy towards the thin film. An energy absorbing body is associated with the thin film to absorb energy and create heat adjacent to the film which in turn causes the thin film to shrink. The energy absorbing body can be the adaptation of the thin film to be opaque to the radiant energy by either being coated with an energy absorbing coating such as printing, or being made partially opaque by means of tinting. The container can also be adapted to absorb energy by including a darkened band adjacent the upper edge of the rim. The device can also interpose an energy absorbing body, such as a darkened aluminum screen adjacent to the film to be heated to cause the thin film to shrink. The device shrinks the thin film around the rim first, then shrinks the film across the top of the container to form a spill-resistant cover. In one embodiment, printed patterns on the film can be used to create perforations.
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FIELD OF THE INVENTION
The invention relates to a method of inhibiting the growth of methane-producing bacteria by exposing the bacteria to a growth inhibiting amount of an HMG-CoA reductase inhibitor. Specifically, the present invention is concerned with inhibiting the production of methane by methane-producing bacteria in the forestomach of ruminant animals, thereby improving the efficiency of ruminant feed utilization.
BACKGROUND OF THE INVENTION
Methane is a waste product of the microbial fermentation of animal feed in the forestomach (rumen) of ruminants. Cattle, sheep and goats convert the products of microbial fermentation, for example, acetate, propionate and butyrate, to meat, milk, wool and leather. Inhibition of microbial methane gas production in the rumen can increase the efficiency of production of beneficial animal products.
Fermentation is the result of the collective action of many different genera of microbes, and this collective action produces both waste methane and worthwhile products. One genus of bacteria, Methanobrevibacter, appears to produce all of the methane in the ruminant forestomach. Hence, it is desirable to have an inhibitor of growth of Methanobrevibacter, which would eliminate methane formation and the loss to the atmosphere of about 6 to 13 percent of the energy of animal feed. Conservation of the energy in indispensable products formed by the other rumen microbes would yield greater efficiency of use of animal feed.
Methane produced in domestic ruminants makes a significant contribution to atmospheric methane. Inhibition of its production would also provide an important environmental benefit by eliminating a major contributor to atmospheric warming.
Currently, a variety of compounds is used to increase feed utilization efficiency and decrease methane production. Monensin (U.S. Pat. No. 3,501,568) and lasalocid are ionophore antibiotics used to alter rumen fermentation. Phthalides enhance propionate production and inhibit methane production in the rumen (U.S. Pat. No. 4,333,923). U.S. Pat. No. 4,225,593 describes the use of aplasmomycin, boromycin and acylated and hydrogenated derivatives thereof to modify rumen metabolism in domestic ruminant animals by reducing the proportion of methane formed, and increasing the proportion of propionate at the expense of methane and/or acetate. Heterocyclic trichloromethyl derivatives (U.S. Pat. No. 4,268,510) have also been used to reduce the production of methane during rumen metabolism and increase the formation of propionate at the expense of acetate, and hence improve the animals' rate of growth and their efficiency of feed utilization.
Prior to applicants' discovery, no antibiotics or drugs were known to inhibit the growth of methanogens without concomitantly inhibiting non-methanogens. Thus it is an important feature of the HMG-CoA reductase inhibitors employed in the present invention that they inhibit the growth of methanogens while minimally inhibiting the growth of non-methane-generating microbes. Few of the commonly used antibiotics that inhibit growth of bacteria or fungi inhibit methanogens.
HMG-CoA reductase inhibitors are well known in the pharmaceutical art to treat hypercholesterolemia in humans. They have not, however, been employed in ruminants.
The present invention relates to the novel use of hydroxymethylglutaryl-CoA reductase inhibitors to inhibit the growth of methane-producing bacteria, and in particular to decrease methane production in ruminant animals, thereby improving feed utilization efficiency.
SUMMARY OF THE INVENTION
In one aspect, the invention relates to the use of hydroxymethylglutaryl-CoA reductase inhibitors to inhibit the growth of methane-producing bacteria.
In another aspect, the invention relates to the use of HMG-CoA reductase inhibitors to inhibit the growth of methane-producing bacteria in the forestomach of ruminant animals. This may be expressed alternatively as a method for reducing ruminal methane production in ruminant animals. The result of the method is an increased efficiency in feed utilization by the animals.
In another aspect, the invention relates to a feed material which incorporates HMG-CoA reductase inhibitors, or to a feed concentrate which may be mixed with conventional feed materials to deliver the appropriate methanogen growth inhibiting dose to the ruminant animals, or administered directly to the animal in the form of an intra-ruminal pellet, bolus or tablet.
In another aspect, the invention relates to a kit for preparing a ruminant feed. The kit includes an HMG-CoA reductase inhibitor and instructions for its use to prepare a ruminant feed.
DETAILED DESCRIPTION OF THE INVENTION
The term "methanogen-growth inhibiting amount", as used herein, refers to an amount of active compound which is sufficient to inhibit the growth of methane-producing organisms. An amount is considered to be sufficient if there is a statistically significant decrease in the number of methanogenic bacteria in the ruminal fluid as determined by methods that enumerate their concentration or activity. Optimally the number of non-methanogenic bacteria in the same sample will remain relatively unchanged, that is, less than 30% decrease will be observed by the same methods.
The term "ruminant" is used in its conventional sense and includes both mature and immature animals. Examples of ruminants are cattle, sheep, deer, goats, musk ox, buffalo, water buffalo and camels.
Presently identified methane-generating bacteria belong to the group Archaea. The predominant genus of Archaea found in the forestomach of cattle, sheep and goats is Methanobrevibacter, and it appears to be responsible for most methane production in ruminants. The non-methane-generating bacteria that have been identified in ruminant forestomach are members of the group Eubacteria.
Presently preferred compounds used to practice the method of the invention are atorvastatin fluvastatin, lovastatin, mevastatin, pravastatin and simvastatin and salts and metabolites thereof. These compounds are disclosed in U.S. Pat. Nos. 4,346,227; 5,030,447; 5,180,589; 4,231,938; 4,444,784; and 5,354,772; which are incorporated herein by reference.
In practicing the present invention, HMG-CoA reductase inhibitors are orally administered to animals in admixture with feed, feed concentrates or supplements, or in dosage forms such as boluses, capsules, tablets, suspensions, emulsions or solutions containing one or more of the inhibitors. These dosage forms are themselves novel and constitute an embodiment of the invention. Formulation of the compounds in such dosage forms can be accomplished by means and methods well known in the veterinary pharmaceutical art. Each individual dosage unit should contain a quantity of the methanogen growth inhibiting compound which has a direct relation to the proper daily dose for the animal to be treated. The effective rumen-modifying amounts of the present compounds may vary depending on many factors, such as, the size of the animal, the species of the animal, the age of the animal, the particular active compound used, the dosage form employed or the particular sensitivity of the particular animal. The determination of an optimum range of an effective amount, based on variables such as those mentioned above, is within the skill of the ordinary artisan. A typical dose for a large ruminant will be in the range of 10 μg to 10 mg per day.
The present compounds are most conveniently incorporated in a standard feed composition in an appropriate amount to achieve the desired daily dosage. This amount will vary depending upon the amount of feed composition consumed daily by the animal. The present compounds may also be incorporated in a mineral, protein or energy-type feed additive supplement in an appropriate amount to provide an effective methanogen growth inhibiting daily dosage.
For commercial use, it is convenient to provide a feed additive premix, mineral supplement or concentrate containing one or more of the HMG-CoA reductase inhibitors. The feed additive premix or concentrate comprises one or more of the HMG-CoA reductase inhibitors and a physiologically acceptable carrier such as soybean meal or ground corn or other edible feed grade material, mineral mixtures or innocuous diluent, such as an alcohol, a glycol or molasses.
The animal feeds most generally used in conjunction with this invention are composed of various grains, grain mixtures and roughage feeds such as hay, cotton seed hulls, rice hulls, silage, or other high fiber feedstuffs commonly fed to meat, milk and wool producing animals, especially in cattle or sheep feeds.
Examples of physiologically acceptable carriers for premix or concentrate compositions include soybean meal, corn oil, ground corn, ground corn cobs, barley wheat, mineral mixtures containing, for example vermiculite or diatomaceous earth, corn gluten meal, corn distillers' solubles or soy flour. The active ingredient will be used in amounts to satisfy the criteria set forth above. This premix or concentrate is then mixed with the normal diet for the animal by the grower or feed mixer. The above mentioned grains, grain mixtures, roughage feeds, usual additives, carriers and innocuous diluents constitute physiologically acceptable adjuvants for purposes of this invention.
A series of tests described below demonstrate that HMG-CoA reductase inhibitors specifically inhibit the growth of methane-producing bacteria.
Methanobrevibacter strains, designated Z4, Z8, and Z10, were isolated from the bovine rumen and were grown anaerobically using the serum bottle modification of the Hungate technique. The medium used contained the following: NaHCO 3 , 7.5 g/L; K 2 HPO 4 0.3 g/L; KH 2 PO 4 , 0.3 g/L; (NH 4 ) 2 SO 4 , 0.3 g/L; NH 4 Cl, 1 g/L; NaCl, 0.6 g/L; MgSO 4 .7H 2 O, 0.12 g/L; CaCl 2 .2H 2 O, 80 mg/L; MgSO 4 .7H 2 O, 30 mg/L; MnSO 4 .H 2 O, 4.5 mg/L; NaCl, 10 mg; FeSO 4 .7H 2 O, 3 mg/L; CoSO 4 .7H 2 O, 1.8 mg/L; ZnSO 4 .7H 2 O, 1.8 mg/L; CuSO 4 .5H 2 O, 100 μg/L; AlK(SO 4 ) 2 .12H 2 O, 180 μg/L; Na 2 MoO 4 .2H 2 O, 100 μg/L; H 3 BO 3 , 100 μg/L; Na 2 SeO 4 , 1.9 mg/L; NiCl 2 .6H 2 O, 92 μg/L; nitrilotriacetic acid, 15 mg/L; thiamine HCl, 2 mg/L; D-pantothenic acid, 2 mg/L; nicotinamide, 2 mg/L; riboflavin, 2 mg/L; pyridoxine HCl, 2 mg/L; biotin, 10 mg/L; cyanocobalamin, 20 μg/L; p-aminobenzoic acid, 100 μg/L; folic acid, 50 μg/L; cysteine HCl.H 2 O, 0.5 g/L; rumen fluid, 100 mL/L; sodium formate, 5 g/L; sodium acetate, 0.5 g/L; glucose, 10 g/L; and yeast extract, 5 g/L. Resazurin (1 mg/L) was added as an oxidation-reduction potential indicator.
Growth inhibition of methanogenic and non-methanogenic bacteria was measured in the following manner. A 0.29 mM stock solution of compactin, which is sold as mevastatin by Sigma Chemical Co. (St. Louis, Mo.) was prepared in 70% ethanol. Prior to bacterial inoculation, 0.1 mL of the mevastatin solution was added to test tubes containing 5 mL of the above-defined medium (final concentration 5.8 nM). Control tubes received 0.1 mL of 70% ethanol or no additive. All tubes also contained 0.15 mL of a solution of 1.25% each of cysteine and sodium sulfide. Each tube was inoculated with 0.5 mL of a methanogenic species or 0.1 mL of a non-methanogenic species and incubated on a rotator at 37 C. Growth was monitored by measuring the optical density of the cultures at 660 nm.
The data in Table 1 demonstrate inhibition of the methanogenic strain Z10. Growth was inhibited after 3 days incubation with mevastatin. In contrast, no inhibition was seen in the non-mevastatin controls. Tables 2 and 3 show similar results for strains Z4 and Z8. No inhibition occurred in the non-methanogenic species of rumen bacteria in the presence of mevastatin. (Table 4).
TABLE 1______________________________________Growth of Z10 ODHrs. No Add Ethanol Drug______________________________________0.00 0.15 0.15 0.1221.17 0.64 0.54 0.1647.42 0.90 0.76 0.1770.42 1.30 0.95 0.2093.17 terminate terminate 0.22110.17 0.25142.17 0.25______________________________________
TABLE 2______________________________________Growth of Z4 ODHrs. No Add Ethanol Drug______________________________________0.00 0.16 0.14 0.1425.50 0.25 0.33 0.1848.50 0.64 0.57 0.2271.25 0.82 0.42 0.2196.25 1.20 0.21 0.22120.25 terminate 0.19 0.20144.25 0.26 0.21216.75 0.26 0.21______________________________________
TABLE 3______________________________________Growth of Z8 ODHrs. No Add Ethanol Drug______________________________________0.00 0.15 0.14 0.1425.50 0.12 0.12 0.1248.50 0.17 0.12 0.1271.25 0.39 0.16 0.1596.25 0.60 0.44 0.13120.25 0.53 1.05 0.13144.25 0.63 terminate 0.14216.75 0.62 0.13______________________________________
TABLE 4______________________________________Non-methanogenic bacteria grown in the presence of mevastatin Growth (OD.sub.660nm)Organism Incubation (h) No drug Drug______________________________________Butyrivibrio 28 1.80 1.90fibrisolvens D1Ruminococcus albus 7 23 1.99 1.80Ruminococcus 48 1.40 1.40flavefaciens C94Bacteroides 48 1.20 1.20succinogenes S85Selenomonas 18 1.70 1.70ruminantium HD4______________________________________
Mevastatin inhibits all strains of Methanobrevibacter, the organism responsible for methane production in the forestomach of the bovine and other ruminants. Rumen species that do not produce methane are not inhibited by mevastatin. The non-methanogenic species tested are representative of bacteria that digest the major plant polysaccharides of the ruminant diet. They also produce the major products that provide the building blocks and energy the animal requires for growth and maintenance.
Prevention of methane production in the rumen by HMG-CoA inhibitors allows the production of products that are useful for the animal, and energy loss in methane released to the atmosphere is minimized. Several studies indicate that co-culture of methanogens with bacteria that produce propionate or succinate, a precursor of propionate, shift fermentations to the production of acetate. R. flavefaciens or Selenomonas ruminantium produce the following fermentation when grown with a methane-producing organism:
1. Hexose→2 Acetate+4 H 2 +2 CO 2 (R. flavefaciens or Selenomonas ruminantium).
2. 4 H 2 +CO 2 →CH 4 +2 H 2 O (methane-producing organism).
Sum:
3. Hexose→2 Acetate+CH 4 +CO 2 +2 H 2 O.
When grown by themselves, the non-methanogenic species produce only small amounts of hydrogen because hydrogen accumulation inhibits the production of hydrogen. Since methanogens use the hydrogen to make methane, they allow continuous production of hydrogen by the non-methanogens because hydrogen does not accumulate.
The fermentations of the non-methanogenic species when hydrogen accumulates are:
4. Hexose+CO 2 →Succinate+Acetate+Formate (R. flavefaciens).
5. 1.5 Hexose→2 Propionate+Acetate+CO 2 (Selenomonas ruminantium).
Therefore, growth with a methanogen suppresses the production of succinate and propionate and increases the formation of acetate and methane. Succinate formed by R. flavefaciens and other bacteria is decarboxylated to propionic acid in the forestomach of ruminants. Therefore, methanogenesis in the forestomach results in depression of propionate production, increased production of acetate, and formation of methane. Eructation then removes methane, a waste product of the fermentation, to the atmosphere.
Propionate is the only rumen fermentation product that is gluconeogenic. The ruminant depends on propionate for anabolism, while butyrate and acetate are utilized primarily for energy and for synthesis of lipids. Diminution of precursors of lipids decreases production of animal fat.
In addition to the above hydrogen-sensitive metabolic pathways, non-methanogenic rumen microbes possess mechanisms for production of hydrogen that are insensitive to inhibition by hydrogen. These mechanisms are primarily related to pyruvate production, which is then converted to acetate, hydrogen and carbon dioxide. Hydrogen does not inhibit this conversion. These pathways produce a considerable amount of hydrogen that methanogens completely use. This raises the question of the fate of hydrogen gas in the forestomach if methanogens are inhibited. It is reasonable to expect that bacteria with mechanisms for activating hydrogen for use in their metabolic pathways would use the available hydrogen. As an illustration, we compare the combined fermentations of B. fibrisolvens and S. ruminantium plus a methanogen with the fermentation of B. fibrisolvens and S. ruminantium without a methanogen.
B. fibrisolvens produces butyrate, formate, hydrogen, and carbon dioxide from carbohydrates. Since formate is essentially equivalent to hydrogen and carbon dioxide in the ecosystem, the fermentation equation is:
6. Hexose→Butyrate+2 H 2 +2 CO 2 .
If this fermentation is coupled to the formation of methane, the equation is:
7. Hexose→Butyrate+0.5 CH 4 +1.5 CO 2
Co-fermentation by butyrate-forming bacteria and methanogens does not influence butyrate formation as it does the formation of succinate and propionate by R. flavefaciens and S. ruminantium and methanogens. The interaction between equation 7 with the fermentation of S. ruminantium with a methanogen (equation 3) gives:
8. 2 Hexose→Butyrate+2 Acetate+1.5 CH 4 +2.5 CO 2 +H 2 O
When drug inhibition of the growth of forestomach methanogens occurs, S. ruminantium could use the hydrogen formed by B. fibrisolvens to produce the following fermentation:
9. 2 Hexose→2 Propionate+Butyrate+2 CO 2 .
(Note that the same fermentation would result from a combination of R. flavefaciens and B. fibrisolvens in the forestomach because formate is equivalent to H 2 +CO 2 and succinate is decarboxylated to propionate.)
These equations highlight the energetic benefit to the animal of inhibition of methanogenesis. Table 5 compares the free energies of the products of the methane yielding fermentations of S. ruminantium and B. fibrisolvens plus a methanogen with the fermentation of S. ruminantium plus B. fibrisolvens. Inhibition of methanogenesis produces a very large energy benefit. Most of it comes from shifting electrons from methane production into production of propionate by S. ruminantium. The energy available to the animal of the non-methanogenic fermentation is 1.65 times the methanogenic fermentation.
TABLE 5______________________________________Comparison of energy recoveries frommethanogenic and non-methanogenic fermentations by S.ruminantium and B. fibrisolvensFree energies of formation per hexose fermented S. ruminatium +Methanogenesis B. Fibrisolvens moles/ kcal/ kcal/ Moles/ kcal/ kcal/Products hexose mol hexose hexose mol hexose______________________________________Acetate 1.00 88.29 88.29 0.00 88.29 0.00Butyrate 0.50 84.28 42.14 0.50 84.28 42.14Methane 0.75 12.13 9.10 0.00 12.13 0.00Propionate 0.00 86.30 0.00 2.0 86.30 172.60Sum 139.53 214.74Net 130.43 214.74(-methane)______________________________________
Inhibition of methanogenesis provides a large energy benefit to the animal, although it is unlikely to be as large as the benefit shown by the above example because not all major rumen carbohydrate-fermenting microbes interact with methanogens. Fibrobacter succinogenes, a major cellulolytic species and members of the genus Prevotella (formerly named Bacteroides), major polysaccharide-using species, form acetate and succinate and do not produce hydrogen in the absence or presence of methanogens. Their fermentations would not be altered by an inhibition of methanogenesis.
The composition of the invention may take the form of a supplemented feedstuff for direct feeding to animals, in which case it will contain from 5 ppm to 3000 ppm of the compound of the invention in admixture with a conventional ruminant feedstuff; or it may take the form of a concentrated premix for dilution with a conventional ruminant feedstuff to produce a supplemented feedstuff suitable for direct feeding, and such a premix will contain from 0.3% w/w to 50% w/w of the compound of the invention in admixture with either a conventional, nutritionally balanced ruminant feedstuff, an inert solid diluent of no energy value, for example ground limestone, or starch or lactose. The HMG-CoA reductase inhibitor is preferably serially diluted with the diluent or carrier in two or more successive stages, to ensure even mixing.
Premixes suitable for dilution with an animal feedstuff may be manufactured by incorporating 10, 25, 50, 100 or 250 g of the HMG-CoA reductase inhibitor in ground limestone so that the final weight of the premix is 500 g. An animal feedstuff suitable for direct feeding to ruminants may be manufactured by intimately mixing this premix with a typical cattle feedstuff, to obtain a ruminant feedstuff containing 10, 25, 50, 100 or 250 g of the compound of the invention per metric ton, according to the concentration of the active ingredient in the premix used.
Typical cattle feedstuffs that may be employed are:
______________________________________ cwt kg______________________________________Dairy CakeBarley meal 101/4 512.5Maize meal 1 50Decorticated ground nut cake 1 50Decorticated cotton seed cake 1 50Extracted cotton seed cake 1 50Wheat feed 3 150Feather meal 1/4 12.5Seaweed meal 1/4 12.5Bone meal 1/4 12.5Chalk 1/4 12.5Molasses 11/2 75Vitamins and trace mineral mix 1/2 12.5 20 1000.0Beef CubeBarley meal 11 550Wheat feed 51/4 262.5Decorticated ground nut cake 1/4 12.5Extracted ground nut cake 42 lbs. 18.75Bone flour 1/4 12.5Chalk 42 lbs. 18.75Salt 14 lbs. 6.25Molasses 2 12.5Urea 1/4 12.5Vitamins and trace mineral mix 14 lbs. 6.25 20 cwt. 1000.00______________________________________
While the specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
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Methods and compositions for decreasing the production of methane in ruminant animals, thereby increasing feed utilization efficiency, are disclosed. The methods employ HMG-CoA reductase inhibitors to selectively inhibit the growth of methane-producing bacteria without significantly inhibiting the growth of non-methanogens.
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[0001] This application claims priority to China Patent Application No. 200820004676.8 filed on Jan. 25, 2008, the disclosure of which is incorporated herein by reference in its entirety.
CROSS-REFERENCES TO RELATED APPLICATIONS
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to a fan structure, and more particularly, relates to a kinetically modulated fan structure.
[0005] 2. Descriptions of the Related Art
[0006] With the rapid development of high-tech industries, various electronic products are becoming more functionally powerful. Accordingly, the power consumption of such products has also continuously increased, which imposes on the requirements needed for heat dissipation. Presently, the rotational speed of common heat dissipating fans needs to reach more than 3000 rpm and even up to above 7000 rpm when operating at high power. At such a high rotational speed, it is essential for the fan structures to be kinetically modulated appropriately to eliminate violent vibration and noises originating from the fans in operation. Unfortunately, to achieve kinetic equilibrium of the fan structures in the prior art is to add counterweights, counterbalance earth or to drill holes, which consumes time, cost and is unstable. Other methods for reaching kinetic equilibrium include hollowing plastic blades or adding a steel housing outside the fan blades. However, these methods also consume time, have high costs and complex manufacturing processes. Additionally, the added materials for kinetic modulation as described above are dissimilar to that of the fan structures, it is common for the materials to flake off after being used for a long time, resulting in a considerable decrease in the service life of fans which are not kinetically modulated well. On the other hand, when the fans are kinetically modulated by cutting off a portion of materials thereof, structural weak points tend to develop locally on the blades and are susceptible to stress concentration, thereby causing damage to the fan structures and consequent decrease in the service life thereof.
[0007] Because conventional methods, which perform modulation on individual fan structures after they are manufactured, are costly, time consuming and have complex processes, it is difficult for the yielded products to provide uniform and stable quality.
[0008] Therefore, it is highly desirable in the field to provide a fan structure that is cost efficient and time efficient to achieve kinetic equilibrium modulation, while preventing damage and providing uniform quality of the yielded products.
SUMMARY OF THE INVENTION
[0009] The objective of this invention is to provide a fan structure which makes an improvement to the conventional kinetic equilibrium modulating methods for fan blades. Specifically, when using the present invention, there is a shorter kinetic modulation time, a lower cost, a simpler process and a longer service life.
[0010] The kinetically modulated fan structure of this invention comprises a housing, a plurality of blades and an equilibrating structure. The housing has a side wall and a top wall with a periphery, while the side wall is disposed along the periphery of the top wall. The plurality of blades are disposed on an outer surface of the side wall. The equilibrating structure is disposed on an inner side of the housing and integrally formed with the housing and the plurality of blades. By integrally forming equilibrating structure, the fan structure of this invention is adapted to be kinetically equilibrated during the manufacturing processes such as injection molding. As a result, the modulation of kinetic equilibrium with respect to individual fan structures can be eliminated since all of the yielded fan structures are uniform and durable in quality. Thus, the kinetic modulation is both time efficient and cost efficient.
[0011] The detailed technology and preferred embodiments implemented for the subject invention are described in the following paragraphs accompanying the appended drawings for people skilled in this field to well appreciate the features of the claimed invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a perspective view of the first embodiment in accordance with this invention;
[0013] FIG. 2 is a perspective view of the second embodiment in accordance with this invention;
[0014] FIG. 3 is a perspective view of the third embodiment in accordance with this invention; and
[0015] FIG. 4 is a perspective view of the fourth embodiment in accordance with this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] The fan structure of this invention utilizes an equilibrating structure disposed therein for kinetic equilibrium modulation. The fan structure comprises a housing, a plurality of blades, an equilibrating structure, a central rotary shaft and a plurality of reinforcing ribs. As shown in FIG. 1 , the housing 1 comprises a side wall and a top wall. A plurality of reinforcing ribs 4 is disposed on the inner side of the top wall, although this invention is not merely limited to this arrangement. The side wall is disposed along a periphery of the top wall. The plurality of blades 2 are disposed on an outer surface of the side wall of the housing 1 . An equilibrating structure is disposed on the inner side of the housing 1 and integrally formed with the housing 1 as well as the plurality of blades 2 . The central rotary shaft extends downward from the inner side of the top wall at a center thereof.
[0017] In the first embodiment of this invention, the equilibrating structure comprises at least one recess 6 disposed on the inner side of the side wall of housing 1 as shown in FIG. 1 . However, in other examples, instead of being disposed on the inner side of the side wall of the housing 1 , the equilibrating structure may also be disposed on the inner side of the top wall of the housing 1 . The equilibrating structure may be also at least one protrusion formed on the inner side of the housing 1 .
[0018] In the first embodiment, the fan structure further comprises an inner hub 3 integrally formed on the inner side of the side wall of the housing 1 . The inner hub 3 is formed with the at least one recess 6 to define the equilibrating structure of this invention. As shown in FIG. 1 , the equilibrating structure comprises a plurality of recesses 6 disposed on the inner hub 3 , which corporately alter the mass distribution of the fan structure to modulate the kinetic equilibrium of the fan structure. It should be noted that a cross section of the recess 6 is not just limited to the quadrangular shape as shown in FIG. 1 , but may also take on a curvilinear, triangular, polygonal shape or the like. Also, the recesses 6 may not extend to the inner side of the top wall of the housing 1 , or extend downwards to the bottom of the inner hub 3 , but may be formed only on a portion of the inner hub 3 . All variations described above may achieve the goal of this invention.
[0019] As shown in both FIGS. 1 and 2 , similar to the first embodiment, a fan structure of the second embodiment of this invention also comprises an inner hub 3 and at least one recess 6 . However, the second embodiment differs from the first embodiment in that the equilibrating structure further comprises at least one protrusion 7 integrally formed on an inner side of the side wall of the housing 2 . The protrusion 7 protrudes inwardly from the side wall through the recess 6 and cooperates with the recess 6 to define the equilibrating structure. The protrusion 7 is not limited to the configuration shown in FIG. 2 , but may also extend to the inner side of the top wall of the housing 1 or extend beyond the recess 6 up to the bottom of the side wall of the housing 1 . Moreover, the protrusion 7 may protrude inwardly from only at least a portion of the recess 6 or may be constructed with different lengths and sectional shapes such as curvilinear, triangular, quadrangular and polygonal shapes. All these variations may achieve the goal of this invention. In the second embodiment, as shown in FIG. 2 , the inner hub 3 is formed with a plurality of protrusions 7 inwardly protruding from the plurality of recesses 6 respectively. The plurality of protrusions 7 and the recesses 6 cooperate with each other to define the equilibrating structure for modulating the kinetic equilibrium of the fan structure.
[0020] As shown in FIG. 3 , a fan structure of the third embodiment of this invention differs from the first and the second embodiment in that the equilibrating structure thereof comprises at least one recess 8 , which is integrally formed on the inner side of the top wall of the housing 1 to define the equilibrating structure and is adapted to kinetically modulate the fan structure. In this embodiment, the equilibrating structure comprises a plurality of recesses 8 integrally formed on the inner side of the top wall of the housing 1 and substantially shaped into circular blind holes. However, in other examples, the recesses 8 may also be blind holes or through-holes in a curvilinear, square, spherical, rectangular, polygonal shape or the like, all of which may achieve the goal of kinetic equilibrium modulation.
[0021] Similarly, in the fourth embodiment of this invention, the equilibrating structure is also integrally formed on the inner side of the top wall of the housing 1 . However, unlike that described in the third embodiment, this equilibrating structure comprises at least one protrusion 9 as shown in FIG. 4 to define the equilibrating structure of this invention. The fan structure of this embodiment comprises a plurality of protrusions 9 , which may be implemented as at least one portion of a sphere. However, in other examples, the protrusion 9 may also take on a cuboidal, cylindrical, conical, hexahedral, tetrahedral, polyhedral or other shapes, all of which variations may modulate the kinetic equilibrium of the fan structure appropriately without departing from the spirit of this invention.
[0022] The equilibrating structures described in the above embodiments are not merely limited to the configurations described therein. For example, the various recesses or protrusions described in the above embodiments may also be applied simultaneously in the fan structure to serve the purpose of kinetic equilibrium modulation for the fan structure.
[0023] When utilizing the equilibrating structure integrally formed in the fan structure in accordance with this invention, the fan structure can be readily kinetically modulated, thus eliminating the need for kinetic equilibrium modulation on individual fan structures. Consequently, the fan structures already kinetically modulated may be mass-produced by only appropriately adjusting the moulds used for manufacturing the fan structures. This not only saves considerable time consumed in kinetic equilibrium modulation, but also provides a uniform quality of the fan structures yielded, thus eliminating the disadvantages in the conventional methods for modulating the kinetic equilibrium of fan structures.
[0024] The above disclosure is related to the detailed technical contents and inventive features thereof. People skilled in this field may proceed with a variety of modifications and replacements based on the disclosures and suggestions of the invention as described without departing from the characteristics thereof. Nevertheless, although such modifications and replacements are not fully disclosed in the above descriptions, they have substantially been covered in the following claims as appended.
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A kinetically modulated fan structure is provided. The fan structure comprises a housing, a plurality of blades and an equilibrating structure, wherein the equilibrating structure is disposed on the inner side of the housing, and formed integrally with the housing and the blades. Thereby, the fan structure is adapted to be kinetically equilibrated during the manufacturing process. As a result, the modulation of the kinetic equilibrium with respect to the fan structure is eliminated since all of the yielded fan structures are uniform in quality. The simplified production is both time efficient and cost efficient, while producing a durable product.
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BACKGROUND
[0001] The present invention relates to polymers that are useful in paper additives.
[0002] “Sizing,” as applied to paper, refers to a fibrous substrate's ability to resist wetting or penetration of a liquid into a paper sheet. Aqueous dispersions of alkenylsuccinic anhydride (ASA) cellulose-reactive sizing agent have been widely used in the paper and board making industry for many years, for sizing a wide variety of grades which include printing and writing grades and bleached and unbleached board grades. Cellulose-reactive alkenylsuccinic anhydride emulsions impart hydrophobic properties to the paper and board products.
[0003] Chemicals used to achieve sizing properties are known as either internal sizes or surface sizes. Internal sizes can be either rosin-based or synthetic sizes such as alkenylsuccinic anhydride, or other materials. Internal sizes are added to the paper pulp prior to sheet formation. Surface sizes are sizing agents that are added after the paper sheet has formed, most generally at the size press, although spraying applications may also be used.
[0004] A synthetic sizing agent such as alkenylsuccinic anhydride sizing agent is ordinarily applied by dispersing it in a cationic or amphoteric hydrophilic substance such as a starch or a polymer. The starch or polymer-dispersed alkenylsuccinic anhydride sizing emulsions have been added to the pulp slurry before the formation of a paper web. This type of addition of alkenylsuccinic anhydride sizing emulsions to the paper making system is commonly called wet-end addition or internal addition of alkenylsuccinic anhydride.
[0005] Papermakers would benefit from a cationic or amphoteric polymer that is different from known polymers and, preferably, that also enhances the sizing efficiency of paper products. Unfortunately, known methods and
[0000] compositions have prevented papermakers from achieving this goal. Known compositions and methods require an unduly large amount of materials to size paper products. Papermakers are under pressure to improve sizing efficiency and, as such, there is an ongoing need to develop products and methods that improve sizing efficiency.
[0006] For the foregoing reasons, there is a need to develop a paper additive that improves the sizing efficiency of paper products.
SUMMARY
[0007] The invention relates to a cationic polymer useful as a papermaking additive, which is obtained by copolymerizing:
[0008] (1) a vinyl monomer of the formula:
[0000] CH 2 ═CR 1 —COA(CH2) n N + R 2 R 2 R 3 X − (I)
[0000] or
[0000] (CH 2 ═CHCH 2 ) 2 N + (R 2 ) 2 X − (Ia)
[0009] wherein R 1 is a hydrogen atom or a methyl group, A is an oxygen atom or NH group, n is 2 or 3, R 2 and R 3 are each a methyl group or an ethyl group and X is a chlorine atom, a bromine atom, or X − is a methyl sulfate ion; and
[0010] (2) a vinyl monomer of the formula:
[0000] CH 2 ═CR 4 —CONH 2 (II)
[0011] wherein R 4 is a hydrogen atom or a methyl group; and
[0012] (3) a vinyl monomer of the formula:
[0000] CH 2 ═CR 5 COO(CH 2 ) n OH (III)
[0000] or
[0000] CH 2 ═CR 6 COO(CH 2 ) m CH(OH)CH 2 OH (IIIa)
[0013] wherein R 5 and R 6 is a hydrogen atom or a methyl group, n is 1-4, inclusive and m is 1 or 2.
[0014] In another embodiment, the invention relates to an amphoteric polymer useful as a papermaking additive, which is obtained by copolymerizing
[0015] (1) a vinyl monomer of the formula:
[0000] CH 2 ═CR 1 —COA(CH2) n N + R 2 R 2 R 3 X − (I)
[0000] or
[0000] (CH 2 ═CHCH 2 ) 2 N + (R 2 ) 2 X − (Ia)
[0016] wherein R 1 is a hydrogen atom or a methyl group, A is an oxygen atom or NH group, n is 2 or 3, R 2 and R 3 are each a methyl group or an ethyl group and X is a chlorine atom, a bromine atom, or X is a methyl sulfate ion; and
[0017] (2) a vinyl monomer of the formula:
[0000] CH 2 ═CR 4 —CONH 2 (II)
[0018] wherein R 4 is a hydrogen atom or a methyl group, and
[0019] (3) a vinyl monomer of the formula:
[0000] CH 2 ═CR 5 COO(CH 2 ) n OH (III)
[0000] or
[0000] CH 2 ═CR 6 COO(CH 2 ) m CHOHCH 2 OH (III a)
[0020] wherein R 5 and R 6 is a hydrogen atom or a methyl group and n is 1 or 4 and m is 1 or 2 ; and
[0021] (4) an anionic vinyl monomer of the formula:
[0000] CH 2 ═CR 7 COOR 8 (IV)
[0000] wherein R 7 is a hydrogen atom or a methyl group, and R 8 is a hydrogen atom, an alkali metal, ammonium group.
[0022] In another embodiment, the invention relates to a method for making the cationic polymer or a method for making the amphoteric polymer.
[0023] In another embodiment, the invention relates to a method comprising (a) providing paper stock; (b) adding to the paper stock a composition comprising:(i) synthetic sizing agent, and (ii) the above described cationic polymer or amphoteric polymer, and (c) forming a web from said paper stock, such that the web exhibits an improved sizing efficiency as compared to a web made without the cationic polymer.
[0024] These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims.
DESCRIPTION
[0025] The invention is based on the remarkable discovery that by using a certain cationic polymer or amphoteric polymer, it is now possible to enhance the sizing efficiency of a paper product.
[0026] Other than in the operating examples or where otherwise indicated, all numbers or expressions referring to quantities of ingredients, reaction conditions, etc., used in the specification and claims are to be understood as modified in all instances by the term “about.” Various numerical ranges are disclosed in this patent application. Because these ranges are continuous, they include every value between the minimum and maximum values. Unless expressly indicated otherwise, the various numerical ranges specified in this application are approximations.
[0027] The term “paper”, as used herein, is meant to include fibrous substrates that include not only paper as the term is commonly used but all types of cellulose-based products in sheet and web form, including, for example, board and paperboard. The sizing compositions may be added to any stock containing cellulosic fibres, optionally in combination with mineral fillers, and usually the content of cellulosic fibres is at least 50% by weight, based on dry stock. Examples of mineral fillers of conventional types include kaolin, china clay, titanium dioxide, gypsum, talc and natural and synthetic calcium carbonates such as chalk, ground marble and precipitated calcium carbonate.
[0028] A cationic polymer of the invention is obtained by copolymerizing
[0029] (1) a vinyl monomer of the formula:
[0000] CH 2 ═CR 1 —COA(CH 2 ) n N + R 2 R 2 R 3 X − (I)
[0000] or
[0000] (CH 2 ═CHCH 2 ) 2 N + (R 2 ) 2 X − (Ia)
[0000] wherein R 1 is a hydrogen atom or a methyl group, A is an oxygen atom or NH group, n is 2 or 3, R 2 and R 3 are each a methyl group or an ethyl group and X is a chlorine atom, a bromine atom, or X − is a methyl sulfate ion; and
[0030] (2) a vinyl monomer of the formula:
[0000] CH 2 ═CR 4 —CONH 2 (II)
[0031] wherein R 4 is a hydrogen atom or a methyl group; and
[0032] (3) a vinyl monomer of the formula:
[0000] CH 2 ═CR 5 COO(CH 2 ) n OH (III)
[0000] or
[0000] CH 2 ═CR 6 COO(CH 2 ) m CHOHCH 2 OH (IIIa)
[0033] wherein R 5 and R 6 is a hydrogen atom or a methyl group, n is 1-4, inclusive and m is 1 or 2.
[0034] The synthetic sizing agent may be any sizing agent that can imparts desired sizing properties. Preferred sizing agents include alkenyl succinic anhydride (ASA) and alkyl ketene dimer (AKD), and alkeno ketene dimer, alkyl isocyanates, and alkyl anhydrides.
[0035] The vinyl monomer (I) may be a quaternary ammonium group-containing vinyl monomer produced by quaternizing a dialkylaminoalkyl ester of acrylic acid or methacrylic acid with an alkyl halide or alkyl sulfate. Specific examples of the vinyl monomer (I) include quaternized products resulting from dimethylaminoethyl acrylate, diethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, etc. As the quaternizing agent, there may be exemplified methyl chloride, methyl bromide, methyl iodide, ethyl bromide, etc.
[0036] The vinyl monomer (Ia) may include diallyidimethylammonium chloride.
[0037] The vinyl monomer (II) includes acrylamide and methacrylamide. These monomers are effective in increasing the molecular weight of the resulting polymer due to its high polymerizability. They are also effective in improving the water solubility of the produced polymer.
[0038] The vinyl monomer (III) may include hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, hydroxyprolyl (meth)acrylate and hydroxybutyl (meth)acrylate.
[0039] The vinyl monomer (IIIa) may include 2,3-dihydroxypropyl (meth)acrylate and 3,4-dihydroxybutyl (meth)acrylate.
[0040] The cationic charge of the cationic polymer ranges from at least 1 to 99 mole %.
[0041] In one embodiment, the cationic polymer has a 2-hydroxyethyl methacrylate ranging from 1 to 30 mole percent. In another embodiment, the cationic polymer has a 2-hydroxyethyl methacrylate ranging from 2 to 20 mole percent. In another embodiment, the cationic polymer has a 2-hydroxyethyl methacrylate ranging from 5 to 10 mole percent.
[0042] Although not required, the cationic polymer can be crosslinked or branched.
[0043] The amphoteric polymer of the invention is generally obtained by copolymerizing:
[0044] (1) a vinyl monomer of the formula:
[0000] CH 2 ═CR 1 —COA(CH2) n N + R 2 R 2 R 3 X − (I)
[0000] or
[0000] (CH 2 ═CHCH 2 ) 2 N + (R 2 ) 2 X −
[0045] wherein R 1 is a hydrogen atom or a methyl group, A is an oxygen atom or NH group, n is 2 or 3, R 2 and R 3 are each a methyl group or an ethyl group and X is a chlorine atom, a bromine atom, or X is a methyl sulfate ion; and
[0046] (2) a vinyl monomer of the formula:
[0000] CH 2 ═CR 4 —CONH 2 (II)
[0047] wherein R 4 is a hydrogen atom or a methyl group, and
[0048] (3) a vinyl monomer of the formula:
[0000] CH 2 ═CR 5 COO(CH 2 ) n OH (III)
[0000] or
[0000] CH 2 ═CR 6 COO(CH 2 ) m CHOHCH 2 OH (IIIa)
[0049] wherein R 5 and R 6 is a hydrogen atom or a methyl group and n is 1 or4 and m is 1 or2; and
[0050] (4) an anionic vinyl monomer of the formula:
[0000] CH 2 ═CR 7 COOR8 (IV)
[0051] wherein R 7 is a hydrogen atom or a methyl group, and R 8 is a hydrogen atom, an alkali metal, ammonium group.
[0052] The anionic vinyl monomer (IV) may include acrylic acid or methacrylic acid.
[0053] The amphoteric polymer preferably has an anionic charge ranging from 0 to 40 mole percent.
[0054] The molecular weight of the cationic polymer or amphoteric polymer varies, depending on the needs at hand. In one embodiment, the cationic polymer or amphoteric polymer has a molecular weight ranging from 10,000 to 3,000,000 daltons average molecular weight. In another embodiment, the cationic polymer or amphoteric polymer has a molecular weight ranging from 100,000 to 2,000,000 daltons average molecular weight. In another embodiment, the cationic polymer or amphoteric polymer has a molecular weight ranging from 100,000 to 1,000,000 daltons average molecular weight. Molecular weights stated herein are weight average.
[0055] The proportion of the vinyl monomers to be copolymerized may be varied depending on the desired properties of the resulting polymer, the kinds of monomers used, the polymerization mode to be adopted, etc. But, the molar proportion of the vinyl monomers (I), (II), (III) and (IV) is usually about 1 to 99:1 to 99:1 to 30:0 to 40, or about 1 to 10:1 to 85:2 to 10:0 to 5
[0056] The copolymerization of the vinyl monomers may be carried out in an aqueous medium in the presence of a catalyst by a per se conventional procedure such as solution polymerization, emulsion polymerization or precipitation polymerization.
[0057] In case of solution polymerization, there may be employed as the reaction medium water, a lower alcohol or their mixture, among which the use of water is particularly preferred. The total concentration of the vinyl monomers in the aqueous medium may be from about 5 to 80% by weight. Depending on the total concentration or composition of the vinyl monomers, the polymer is produced in a form ranging from a fluidizable liquid to a non-fluidizable solid. When the product is a liquid, it may be used as such. When the product is a solid, it may be crushed, if necessary, followed by drying to give a powdery material.
[0058] In use, the invention provides valuable methods. In one embodiment, the invention relates to a method that includes the steps of (a) providing paper stock; (b) adding to the paper stock a composition comprising:(i) synthetic sizing agent, and (ii) a cationic polymer useful as a paper additive obtained by copolymerizing:
[0059] (1) a vinyl monomer of the formula:
[0000] CH 2 ═CR 1 —COA(CH2) n N + R 2 R 2 R 3 X − (I)
[0000] or
[0000] (CH 2 ═CHCH 2 ) 2 N + (R 2 ) 2 X −
[0060] wherein R 1 is a hydrogen atom or a methyl group, A is an oxygen atom or NH group, n is 2 or 3, R 2 and R 3 are each a methyl group or an ethyl group and X is a chlorine atom, a bromine atom, or X − is a methyl sulfate ion; and
[0061] (2) a vinyl monomer of the formula:
[0000] CH 2 ═CR 4 —CONH 2 (II)
[0062] wherein R4 is a hydrogen atom or a methyl group, and
[0063] ( 3 ) a vinyl monomer of the formula:
[0000] CH 2 ═CR 5 COO(CH 2 ) n OH (III)
[0000] or
[0000] CH 2 ═CR 6 COO(CH 2 ) m CHOHCH 2 OH
[0064] wherein R 5 and R 6 is a hydrogen atom or a methyl group and n is 1-4, inclusive and m is 1 or 2.(iii) water or starch solution, and
[0065] (c) forming a web from said paper stock, such that the web exhibits an improved sizing efficiency as compared to a web made without the cationic polymer.
[0066] When the amphoteric polymer of the invention is used, the invention provides a method that includes the steps of (a) providing paper stock; (b) adding to the paper stock a composition comprising: (i) a synthetic sizing agent, and (ii) the amphoteric polymer useful as a paper additive, which is obtained by copolymerizing
[0067] (1) a vinyl monomer of the formula:
[0000] CH 2 ═CR 1 —COA(CH 2 ) n N + R 2 R 2 R 3 X − (I)
Or
[0068] (CH 2 ═CHCH 2 ) 2 N + (R 2 ) 2 X −
[0069] wherein R 1 is a hydrogen atom or a methyl group, A is an oxygen atom or NH group, n is 2 or 3, R 2 and R 3 are each a methyl group or an ethyl group and X is a chlorine atom, a bromine atom, or X is a methyl sulfate ion; and
[0070] (2) a vinyl monomer of the formula:
[0000] CH 2 ═CR 4 —CONH 2 (II)
[0071] wherein R 4 is a hydrogen atom or a methyl group, and
[0072] (3) a vinyl monomer of the formula:
[0000] CH 2 ═CR 5 COO(CH 2 ) n OH (III)
[0000] or
[0000] CH 2 ═CR 6 COO(CH 2 ) m CHOHCH 2 OH (IIIa)
[0073] wherein R 5 and R 6 is a hydrogen atom or a methyl group and n is 1 or 4 and m is 1 or 2.
[0074] (4) an anionic vinyl monomer of the formula:
[0000] CH 2 ═CR 7 COOR 8 (IV)
[0075] wherein R 7 is a hydrogen atom or a methyl group, and R 8 is a hydrogen atom, an alkali metal, ammonium group;
[0076] (iii) water or starch solution, and
[0077] (c) forming a web from said paper stock, such that the web exhibits an improved sizing efficiency as compared to a web made without the amphoteric polymer.
[0078] When a polymer of the invention is added to the surface of paper., the invention provides a method that involves the steps of (a) providing paper stock; (b) forming a web from said paper stock, (c) adding to the web a composition cationic polymer or the amphoteric polymer. Such a polymer is added to the surface of a fibrous subtrate by any suitable means, e.g., by size press application, spraying and/or water box application.
[0079] In the embodiment in which the surface of paper is treated, anionic or non-ionic polymers may also be used. In this embodiment, non-ionic polymers are obtained by copolymerizing vinyl monomers of formulae (II) and (III) and/or (IIIa). Anionic polymers can obtained by copolymerizing monomers of formula (II), and (III), and/or (IIIa), and (IV).
[0080] The synthetic sizing agent can be applied in various amounts. For instance, the synthetic sizing agent is generally applied at a dosage ranging from 0.1 kg/metric ton to 10 kg/metric ton, or 0.5 to 5, or from 1 to 4. In one embodiment, the synthetic sizing agent:polymer is added to the paper stock at weight ratios that enable the resulting web to exhibit an improved sizing efficiency as compared to a web made without the cationic polymer. In one embodiment, the the synthetic sizing agent :polymer is added at a weight ratio ranging from 1:0.05 to 1:1. In another embodiment, the synthetic sizing agent :polymer is added at a weight ratio ranging from 1:0.1 to 1:0.5. In another embodiment, the synthetic sizing agent:polymer is added at a weight ratio ranging from 1:0.1 to 1:0.2.
[0081] The synthetic sizing agent can also be added in various forms. In one embodiment, the synthetic sizing agent is emulsified with a polymer. In another embodiment, the sizing agent is emulsified with water and surfactants. In another embodiment, the sizing agent is emulsified in starch.
[0082] In one embodiment, for instance, the synthetic sizing agent is added as a sizing emulsion containing a surfactant and the emulsion is prepared under low shear conditions, e.g. those shearing conditions are created by a device selected from the group of centrifugal pumps, static in-line mixers, peristaltic pumps, magnetic stirring bar in a beaker, overhead stirrer, and combinations thereof. In another embodiment, the synthetic sizing agent is added as a sizing emulsion containing surfactant and the emulsion is prepared under high shear conditions.
[0083] Examples of suitable surfactants include but are not limited to alkyl and aryl primary, secondary and tertiary amines and their corresponding quaternary salts, sulfosuccinates, fatty acids, ethoxylated fatty acids, fatty alcohols, ethoxylated fatty alcohols, fatty esters, ethoxylated fatty esters, ethoxylated triglycerides, sulfonated amides, sulfonated amines, ethoxylated polymers, propoxylated polymers or ethoxylated/ propoxylated copolymers, polyethylene glycols, phosphate esters, phosphonated fatty acid ethoxylates, phosphonated fatty alcohol ethoxylates, and alkyl and aryl sulfonates and sulfates. Examples of preferred suitable surfactants include but are not limited to amides; ethoxylated polymers, propoxylated polymers or ethoxylated/propoxylated copolymers; fatty alcohols, ethoxylated fatty alcohols, fatty esters, carboxylated alcohol or alkylphenol ethoxylates; carboxylic acids; fatty acids; diphenyl sulfonate derivatives; ethoxylated alcohols; ethoxylated fatty alcohols; ethoxylated alkylphenols; ethoxylated amines; ethoxylated amides; ethoxylated aryl phenols; ethoxylated fatty acids; ethoxylated triglycerides; ethoxylated fatty esters; ethoxylated glycol esters; polyethylene glycols; fatty acid esters; glycerol esters; glycol esters; certain lanolin-based derivatives; monoglycerides, diglycerides and derivatives; olefin sulfonates; phosphate esters; phosphorus organic derivatives; phosphonated fatty acid ethoxylates, phosphonated fatty alcohol ethoxylates; polyethylene glycols; polymeric polysaccharides; propoxylated and ethoxylated fatty acids; alkyl and aryl sulfates and sulfonates; ethoxylated alkylphenols; sulfosuccinamates; sulfosuccinates.
[0084] In one embodiment, the surfactant component includes an amine selected from the group consisting of trialkyl amine of the formula (I):
[0000]
[0000] dimethyl sulfate quaternary salt of trialkyl amine of the formula (I), benzyl chloride quaternary salt of trialkyl amine of the formula (I), and diethyl sulfate quaternary salt of trialkyl amine of the formula (I), in which R 1 is methyl or ethyl, R 2 is methyl or ethyl, and R 3 is alkyl having 14 to 24 carbon atoms. In another embodiment, the surfactant excludes this amine. The surfactant levels can range from about 0.1 weight % up to about 20 weight % based on the alkenylsuccinic anhydride component.
[0085] The order in which the synthetic sizing agent is added can vary. In one embodiment, the synthetic sizing agent is added in conjunction with the cationic polymer.
[0086] The sizing efficiency improvement provided by the method can be determined by various methods. For instance, the sizing efficiency: resistance of water to paper increase measurements can be determined by the ink penetration test or the Cobb test.
[0087] The sizing efficiency improvement can range from 10 to 200 percent more, as compared to when the paper is prepared without the polymer.
[0088] The paper made with a method of the invention has favorable qualities. In one embodiment, the paper has a ink penetration ranging from 50 to 1500 seconds. In another embodiment, the paper has a cobb value ranging from 15 to 200 grams/m 2
[0089] The invention is further described in the following illustrative examples in which all parts and percentages are by weight unless otherwise indicated.
EXAMPLES
Example 1 (Comparative)
[0090] A low molecular weight 90/10 mole % acrylamide/[2-(methyl-acryloyloxy ) ethyl]trimethylammonium chloride copolymer (AMD/Q6) was prepared by a free radical co-polymerization. The polymerization process was carried out by simultaneous, continuous addition of ammonium persulfate and monomer solutions to a reaction vessel that contained deionized water and chelating agent buffered with malic acid. The monomer solution was prepared by mixing 45.62 parts of 52.96% acrylamide solution, 10.45 parts of 75% Q6 solution, 2.4 parts of 2% sodium hypophosphite solution, and 53.93 parts of deionized water. The pH of the monomer solution was adjusted from 4.14 to 3.78 with a 20% solution of malic acid. The monomer solution was sparged with nitrogen for an hour before addition. The reactor vessel solution was prepared by addition of 278.46 parts of deionized water and 0.27 parts of 40% pentasodium diethylenepentaacetate. The pH of the reactor vessel solution was adjusted from 10.63 to 3.76 with 0.57 parts of 20% malic acid solution. The latter solution was sparged with nitrogen for an hour.
[0091] The initiator solution was prepared by addition of 0.38 parts of ammonium persulfate into 7.87 parts of deionized water. This solution was sparged with nitrogen for half an hour just prior to use. The addition of monomer solution and ammonium persulfate solution to the reactor vessel 5 was carried out over 2.25 hr and 2.5 hr, respectively. The polymerization reaction was performed at 65° C. The reaction solution was maintained under the nitrogen purge throughout the course of reaction.
[0092] The pH of the final product was equal to 3.1, bulk viscosity was equal to 90 cP (measured using Brookfield viscometer model DV-III, # 3 spindle, 12 rpm, at 25° C.) and viscosity of a 2% polymer solution was equal to 12 cP (measured using Brookfield viscometer model DV-III, # 2 spindle, 30 rpm, at 25° C.). Molecular weight of this polymer (Mw) is equal to 227,000 daltons.
Example 2
[0093] A low molecular weight 90/10/5 mole % acrylamide/[2-(methylacryloyloxy)ethyl]trimethylammonium chloride/2-hydroxyethy methacrylate (AMD/Q6/HEMA) terpolymer was prepared by a free radical co-polymerization. The polymerization process was carried out by simultaneous, continuous addition of ammonium persulfate and monomer solutions to a reaction vessel that contained deionized water and chelating agent buffered with malic acid. The monomer solution was prepared by mixing 41.64 parts of 52.96% acrylamide solution, 10.11 parts of 75% Q6 solution, 2.44 parts of 97% HEMA solution, 2.4 parts of 2% sodium hypophosphite solution, and 55.86 parts of deionized water. The pH of this solution was equal to 3.82. The monomer solution was sparged with nitrogen for an hour before addition. The reactor vessel solution was prepared by mixing 278.27 parts of deionized water and 0.27 parts of 40% pentasodium diethylenepentaacetate. The pH of the reactor vessel solution was adjusted from 10.47 to 3.63 with 0.76 parts of 20% malic acid solution. The latter solution was sparged with nitrogen for an hour just prior to use. The initiator solution was prepared by addition of 0.38 parts of ammonium persulfate into 7.87 parts of deionized water. This solution was sparged with nitrogen for half an hour prior to use. The addition of monomer solution and ammonium persulfate solution to the reactor vessel was carried out over 2.25 hr and 2.5 hr, respectively. The polymerization reaction was performed at 65° C. The reaction solution was maintained under the nitrogen purge throughout the course of reaction.
[0094] The pH of final product was equal to 3.1, bulk viscosity was equal to 70 cP (measured using Brookfield viscometer model DV-III, # 3 spindle, 12 rpm, at 25° C.) and viscosity of a 2% polymer solution was equal to 11 cP (measured using Brookfield viscometer model DV-III, # 2 spindle, 30 rpm, at 25° C.). Molecular weight of this polymer (Mw) is equal to 257,000 daltons.
[0095] Example 3
[0096] Evaluation of polymers from Example 1 and 2 was done by preparation of ASA emulsions with these polymers, characterization of the emulsion particle size distribution (Table 1), addition of these emulsions to the paper slurry, forming paper handsheets and measuring handsheets sizing (Table 2).
[0097] Emulsification of ASA Using Polymers
[0098] Alkenyl succinic anhydride (ASA) emulsions were prepared with polymers from example 1 and 2 at a 1/0.1 ASA/polymer ratio. Concentration of ASA during the emulsification was equal to 3.85 wt. %. ASA emulsions were prepared by following procedure:
Solution of each polymer was prepared at 0.4-wt. % concentration on real basis using DI water. 96.15 g of a polymer solution was placed in a small stainless steel blender jar, and the blender was started at a low speed. While mixing, 3.85 g of ASA was added to a polymer solution by the means of plastic syringe. The speed of blender was immediately changed from low to high and the timer was started. The emulsification was carried out for 3 min at a high speed. The emulsion particle size was measured using Particle Size Analyzer Horiba LA 700. A solution of 0.25 wt. % ASA concentration was prepared using deionized water adjusted with dilute hydrochloric acid to pH 3. The emulsion was placed in ice water and immediately used for handsheet preparation.
Handsheet Preparation Process
[0106] Handsheets were prepared using a furnish of a 50/50 mixture of bleached hardwood and softwood kraft pulp refined to a Canadian Standard Freeness of 500 to which 15% by weight of precipitated calcium carbonate was added, and pH was adjusted to 7.8.
Deionized water was used for furnish preparation, and additional 80 ppm of sodium sulfate and 50 ppm of calcium chloride were added.
[0107] While mixing, a batch of 0.71% solids containing 10 g of cellulose fibers and calcium carbonate was treated with an ASA emulsion. After 60-sec contact time, an anionic retention aid was added and mixing continued for 15 sec. Three 2.8-g sheets of paper were formed using Standard (8″×8″) Nobel & Woods handsheet mold, to target basis weight of 50 Ib/Tappi Ream ,pressed between felts in the nip of a pneumatic roll press at about 15 psi and dried on the rotary dryer at 240° F. The dose of 3 lb/T of ASA and 1 lb/T of an anionic retention aid were applied.
[0108] Evaluation of Paper Sizing
[0109] The sizing of handsheets was tested using Bayer Ink Penetration test (BIP).
[0110] The BIP size testing method provides a fully automated application of ink to the under surface of the paper together with automatic measurement of the optical end point. This method uses the same principle as the TAPPI T 530 test but uses an instrument of our design, which provides an automated design and different geometry for light sources and detector. In particular, all steps of the BIP test were performed automatically with this apparatus. On the push of a start button, ink was pumped into a well until the ink contacted the under surface of the paper, determined electronically, and the timing of the ink penetration was obtained from a reflectance measurement and was displayed digitally. Neutral ink buffered to pH 7. 0 was used in all BIP testing and was prepared by dissolving 12. 5 g of naphthol green B dye in 500 mL of deionized water, and a pH 7 buffer solution was then added to bring the total volume to1000 mL at 23° C.
[0111] Handsheets were evaluated by the BIP test after a conditioning period of at least one day at 72 F and 50% relative humidity. Three handsheet specimens were tested, with two repetitions on each felt side, for a total of six tests.
[0112] To begin a BIP test, each paper specimen was inserted into the apparatus. A fiber optic source cable provided uniform illumination of the topside of the specimen.
[0000] A detector fiber optic cable viewed the same area of illumination. The initial reflectance of the specimen was determined automatically and stored for reference. The test ink was automatically metered by a metering pump from a reservoir into the bottom of a cone-shaped ink well until the ink contacted the underside of the paper specimen under test, at which time a timer was started electronically. The change in reflectance was periodically monitored automatically and the timer was stopped when a pre-specified percentage decrease in reflectance was reached. This decrease was about 20%, i. e., the specimen retained about 80% of its initial reflectance. The elapsed time of the test was displayed and recorded to the nearest second. Then a drain pump was started automatically and run for a period of time long enough to empty the ink in the well into a waste reservoir. The average test time for the three specimens on the felt side were calculated.
[0000]
TABLE 1
ASA Emulsion Particle Size Distribution
Percent of
Size Under
Median
Particles
Which
ASA/
Particle
Under 1
Are 90% of
Particle Size
Polymer
Polymer
Size
micron
Particles
Distribution
ID
Ratio
(microns)
(%)
(micron)
Graph
Example 1
1/0.1
0.631
72.6
1.771
Normal with
shoulder
Example 2
1/0.1
0.490
95.8
0.835
Normal
[0000]
TABLE 2
Sizing Efficiency of ASA Emulsion
ASA/Polymer
Sizing (sec)
Polymer ID
Polymer Description
Ratio
3 lb/T ASA
Example 1
Low MW Copolymer
1/0.1
146
Example 2
Low MW Terpolymer
1/0.1
290
[0113] In Table 1 it is shown that ASA emulsion prepared with a polymer from Example 2 has smaller median particle size and narrower particle size distribution. In Table 2 it is shown that ASA emulsion prepared with polymer from Example 2 provides higher sizing than ASA emulsion prepared with a polymer from Example 1.
Example 4
[0114] A low molecular weight 90/10/5/4 mole % acrylamide/[2-(methylacryloyloxy)ethyl]trimethylammonium chloride/2-hydroxyethy methacrylate/acrylic acid (AMD/Q6/HEMA/AA) tetrapolymer was prepared by a free radical co-polymerization. The polymerization process was carried out by simultaneous, continuous addition of ammonium persulfate and monomer solutions to a reaction vessel that contained deionized water and chelating agent buffered with malic acid. The monomer solution was prepared by mixing 99.13 parts of 52.96% acrylamide solution, 25.28 parts of 75% Q6 solution, 6.11 parts of 97% HEMA solution, 2.66 parts of 99% acrylic acid solution, 5.0 parts of 4% sodium hypophosphite solution, and 10.32 parts of deionized water. The pH of this solution was equal to 2.12. The monomer solution was sparged with nitrogen for an hour before addition. The reactor vessel solution was prepared by mixing 242.7 parts of deionized water and 0.27 parts of 40% pentasodium diethylenepentaacetate. The pH of the reactor vessel solution was adjusted from 10.69 to 4.53 with 0.28 parts of 20% malic acid solution. The latter solution was sparged with nitrogen for an hour prior to use. The initiator solution was prepared by addition of 0.96 parts of ammonium persulfate into 7.28 parts of deionized water. This solution was sparged with nitrogen for half an hour prior to use. The addition of monomer solution and ammonium persulfate solution to the reactor vessel was carried out over 2.25 hr and 2.5 hr, respectively. The polymerization reaction was performed at 65° C. The reaction solution was maintained under the nitrogen purge throughout the course of reaction.
[0115] The pH of final product was equal to 2.03, bulk viscosity was equal to 2310 cP (measured using Brookfield viscometer model DV-III, # 3 spindle, 12 rpm, at 25° C.) and viscosity of a 2% polymer solution was equal to 7.0 cP (measured using Brookfield viscometer model DV-III, # 2 spindle, 30 rpm, at 25° C.). Molecular weight of this polymer (Mw) is equal to 212,000 daltons.
Example 5
[0116] ASA emulsions were prepared with polymers from Examples 1, 2 and 4 at a 1/0.2 ASA/polymer ratio. Concentration of ASA during the emulsification was equal to 3.85 wt. %. ASA emulsions were prepared by the procedure described in Example 3 except that 0.8% polymer solution was used for emulsification. Handsheets were made and tested as it was described in Example 3.
[0000]
TABLE 3
ASA Emulsion Particle Size Distribution
Percent of
Size Under
Median
Particles
Which Are
ASA/
Particle
Under 1
90% of
Particle Size
Polymer
Polymer
Size
micron
Particles
Distribution
ID
Ratio
(microns)
(%)
(micron)
Graph
Example 1
1/0.2
0.589
73.0
2.062
Normal with
(compara-
shoulder
tive)
Example 2
1/0.2
0.509
86.0
1.210
Normal
Example 4
1/0.2
0.550
81.2
1.032
Normal
[0000]
TABLE 4
Sizing Efficiency of ASA Emulsion (Example 1, 2 and 3)
ASA/Polymer
Sizing (sec)
Polymer ID
Polymer Description
Ratio
3 lb/T ASA
Example 1
Low MW Copolymer
1/0.2
440
(comparative)
Example 2
Low MW Terpolymer
1/0.2
560
Example 4
Low MW Tetrapolymer
1/0.2
495
[0117] In Table 3 it is shown that ASA emulsions prepared with a polymer from Example 2 and 4 have smaller median particle size and narrower particle size distribution than ASA emulsion prepared with a polymer from Example 1. Table 4 shows that ASA emulsified with polymers from Example 2 and 4 provides higher sizing than ASA emulsified with a polymer from Example 1.
Example 6
[0118] ASA emulsion is prepared with a polymer from Example 4 at an ASA/polymer ratio of 1/0.2 and 1/1. These emulsions were compared to ASA emulsions prepared with conventional cationic starch at ASA/starch ratios of 1/0.2 and 1/1.
[0119] Emulsions were prepared as described in Example 3, except that a 0.8 wt. % polymer or starch solution was used to make an emulsion at 1/0.2 ASA/emulsifier ratio, and a 4 wt % solution of polymer or starch was used to make an emulsion at 1/1 ASA/emulsifier ratio. Stability of emulsions was checked after 2 hrs.
[0120] Handsheets were made and tested as it was described in Example 3.
[0000]
TABLE 5
ASA Emulsion Particle Size Distribution
Percent of
Median
Particles
Size Under Which
Particle Size
Emulsion
ASA/Polymer
Particle Size
Under 1 micron
Are 90% of Particles
Distribution
After
Polymer ID
Ratio
(microns)
(%)
(micron)
Graph
2 hr
Example 4
1/0.2
0.599
81.2
1.363
Normal
No change
Example 4
1/1
0.55
89.5
1.032
Normal
No change
Starch
1/0.2
10.498
15.6
19.170
Bimodal
Separated
Starch
1/1
0.614
84.7
1.143
Normal
Agglomerated
[0000]
TABLE 6
Sizing Efficiency of ASA Emulsion (Example 3 and Starch)
ASA/Polymer
Sizing (sec)
Polymer ID
Ratio
3 lb/T ASA
Example 4
1/0.2
495
Example 4
1/1
733
Starch
1/0.2
0
Starch
1/1
1005
[0121] At a 1/0.2 ASA/polymer ratio, ASA emulsion prepared with polymer from Example 4 has small median particle, narrow particle size distribution and is stable for at least two hours. This emulsion provides sizing of paper.
[0122] At the ratio of 1/0.2 ASA/starch, ASA emulsion has large median particle size, bimodal distribution and separates within 30 min. This emulsion doesn't provide sizing.
[0123] At the ratio of 1/1 of ASA/polymer and ASA/starch, ASA emulsions prepared with polymer and with starch have small median particle size and narrow particle size distribution, however ASA/starch emulsion is not useable after 2 hour, while ASA/polymer emulsion is not changed for at least two hours.
[0124] At 1/1 ratio, ASA emulsion prepared with starch outperforms emulsion prepared with polymer.
Example 7 (Comparative)
[0125] A high molecular weight 90/10 mole % acrylamide/ [2-(methylacryloyloxy)ethyl]trimethylammonium chloride copolymer (AMD/Q6) was prepared by a free radical co-polymerization. The polymerization process was carried out by simultaneous, continuous addition of ammonium persulfate and monomer solutions to a reaction vessel that contained deionized water and chelating agent buffered with malic acid. The monomer solution was prepared by mixing 45.62 parts of 52.96% acrylamide solution, 10.45 parts of 75% Q6 solution, and 56.30 parts of deionized water. The pH of the monomer solution was adjusted from 4.1 to 3.7 with 0.08 parts of 20% solution of malic acid. The monomer solution was sparged with nitrogen for an hour prior to addition. The reactor vessel solution was prepared by mixing 278.41 parts of deionized water and 0.27 parts of 40% pentasodium diethylenepentaacetate. The pH of the reactor vessel solution was adjusted from 10.8 to 3.8 with 0.62 parts of 20% malic acid solution. The latter solution was sparged with nitrogen for an hour prior to addition.
[0126] The initiator solution was prepared by addition of 0.22 parts of ammonium persulfate into 8.03 parts of deionized water. This solution was sparged with nitrogen for half an hour prior to use. The addition of monomer solution and ammonium persulfate solution to the reactor vessel was carried out over 2.25 hr and 2.5 hr, respectively. The polymerization reaction was performed at 65° C. The reaction solution was maintained under the nitrogen purge throughout the course of reaction.
[0127] The pH of final product was equal to 3.05, bulk viscosity was equal to 2389 cP (measured using Brookfield viscometer model DV-III, # 3 spindle, 12 rpm, at 25° C.) and viscosity of a 2% polymer solution was equal to 62 cP (measured using Brookfield viscometer model DV-III, # 2 spindle, 30 rpm, at 25° C.). Molecular weight of this polymer (Mw) is equal to 1,000,000 daltons.
Example 8
[0128] A high molecular weight 90/10/5 mole % acrylamide/ [2-(methylacryloyloxy) ethyl]trimethylammonium chloride/2-hydroxyethy methacrylate (AMD/Q6/HEMA) terpolymer was prepared by a free radical copolymerization. The polymerization process was carried out by simultaneous, continuous addition of ammonium persulfate and monomer solutions to a reaction vessel that contained deionized water and chelating agent buffered with malic acid. The monomer solution was prepared by mixing 41.64 parts of 52.96% acrylamide solution, 10.11 parts of 75% Q6 solution, 2.44 parts of 97% HEMA solution, and 58.26 parts of deionized water. The pH of this solution was equal to 3.62. The monomer solution was sparged with nitrogen for an hour before addition. The reactor vessel solution was prepared by mixing 278.30 parts of deionized water and 0.27 parts of 40% pentasodium diethylenepentaacetate. The pH of the reactor vessel solution was adjusted from 10.87 to 3.81 with 0.73 parts of 20% malic acid solution. The latter solution was sparged with nitrogen for an hour prior to use.
[0129] The initiator solution was prepared by addition of 0.26 parts of ammonium persulfate into 7.99 parts of deionized water. This solution was sparged with nitrogen for half an hour prior to use. The addition of monomer solution and ammonium persulfate solution to the reactor vessel was carried out over 2.25 hr and 2.5 hr, respectively. The polymerization reaction was performed at 65° C. The reaction solution was maintained under the nitrogen purge throughout the course of reaction.
[0130] The pH of final product was equal to 3.16, bulk viscosity was equal to 1400 cP (measured using Brookfield viscometer model DV-III, # 3 lo spindle, 12 rpm, at 25° C.) and viscosity of a 2% polymer solution was equal to 50 cP (measured using Brookfield viscometer model DV-III, # 2 spindle, 30 rpm, at 25° C.). Molecular weight of this polymer (Mw) is equal. to 1,050,000 daltons.
Example 9
[0131] ASA emulsions were prepared with polymers from Examples 7 and 8 at a 1/0.1 ASA/polymer ratio. Concentration of ASA during the emulsification was equal to 3.85 wt. %. ASA emulsions were prepared, and handsheets were made and tested as it was described in Example 3.
[0000]
TABLE 7
ASA Emulsion Particle Size Distribution
Median
Percent of
Size Under
ASA/
Particle
Particles Under
Which Are 90%
Polymer
Size
1 micron
of Particles
Polymer ID
Ratio
(microns)
(%)
(micron)
Example 7
1/0.1
1.192
43.4
2.913
(comparative)
Example 8
1/0.1
0.773
59.8
2.412
[0000]
TABLE 8
Sizing Efficiency of ASA Emulsion
ASA/Polymer
Sizing (sec)
Polymer ID
Polymer Description
Ratio
3 lb/T ASA
Example 7
High MW Copolymer
1/0.1
131
(comparative)
Example 8
High MW Terpolymer
1/0.1
332
[0132] In Table 7 it is shown that an ASA emulsion prepared with the polymer from Example 8 has smaller median particle size than an emulsion prepared with the polymer from
[0133] Example 7. As it is shown in Table 8, sizing obtained with ASA emulsified Example 8 is significantly higher than sizing obtained with ASA emulsified with Example 7.
Example 10
[0134] A high molecular weight 90/10/5 mole % acrylamide/[2-(methylacryloyloxy)ethyl]trimethylammonium chloride/2,3-dihydroxypropyl methacrylate (AMD/Q6/DHPMA) terpolymer was prepared by a free radical co-polymerization. The polymerization process was carried out by simultaneous, continuous addition of ammonium persulfate and monomer solutions to a reaction vessel that contained deionized water and chelating agent buffered with malic acid. The monomer solution was prepared by mixing 40.93 parts of 52.96% acrylamide solution, 9.93 parts of 75% Q6 solution, 2.87 parts of 100% DHPMA, and 58.66 parts of deionized water. The pH of this solution was adjusted from 4.9 to 4.05 with 0.6 parts of 20 % malic acid solution. The monomer solution was sparged with nitrogen for an hour before addition. The reactor vessel solution was prepared by mixing 278.65 parts of deionized water and 0.27 parts of 40% pentasodium diethylenepentaacetate. The pH of the reactor vessel solution was adjusted from 10.15 to 3.80 with 0.38 parts of 20% malic acid solution. The latter solution was sparged with nitrogen for an hour prior to addition.
[0135] The initiator solution was prepared by addition of 0.26 parts of ammonium persulfate into 7.99 parts of deionized water. This solution was sparged with nitrogen for half an hour prior to use. The addition of monomer solution and ammonium persulfate solution to the reactor vessel was carried out over 2.25 hr and 2.5 hr, respectively. The polymerization reaction was performed at 65° C. The reaction solution was maintained under the nitrogen purge throughout the course of reaction. The pH of final product was equal to 3.16, bulk viscosity was equal to 920 cP (measured using Brookfield viscometer model DV-III, # 3 spindle, 12 rpm, at 25° C.), and viscosity of a 2% polymer solution was equal to 39 cP (measured using Brookfield viscometer model DV-III, # 2 spindle, 30 rpm, at 25° C.).
Example 11
[0136] ASA emulsions were prepared with polymers from Examples 7, 8 and 10 at a 1/0.1 ASA/polymer ratio. Concentration of ASA during the emulsification was equal to 7.4 wt. %. ASA emulsions were prepared as it was described in Example 3, except that 7.4 grams of ASA was added to 92.6 g of a 0.8 wt % polymer solution. Handsheets were made and tested as it was described in Example 3.
[0000]
TABLE 9
ASA Emulsion Particle Size Distribution
Percent of
Size Under
ASA
Median
Particles
Which Are
ASA/
Concen-
Particle
Under 1
90% of
Polymer
tration
Size
micron
Particles
Polymer ID
Ratio
(%)
(microns)
(%)
(micron)
Example 7
1/0.1
7.4
0.909
55
2.153
(comparative)
Example 8
1/0.1
7.4
0.702
66.5
1.990
Example 10
1/0.1
7.4
0.714
65.7
1.942
[0000]
TABLE 10
Sizing Efficiency of ASA Emulsion (Examples 4 and 5)
ASA/Polymer
Sizing (sec)
Polymer ID
Polymer Description
Ratio
3 lb/T ASA
Example 7
High MW Copolymer
1/0.1
206
(comparative)
Example 8
High MW Terpolymer
1/0.1
349
Example 10
High MW Terpolymer
1/0.1
327
[0137] In Table 9 it is shown that ASA emulsions prepared with polymers from Example 8 and 10 have smaller median particle size than the emulsion prepared with the polymer from Example 7. As it is shown in Table 10, sizing obtained with ASA emulsified with polymers from Examples 8 and 10 is significantly higher than sizing obtained with ASA emulsified with the polymer from Example 7.
[0138] Although the present invention has been described in detail with reference to certain preferred versions thereof, other variations are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the versions contained therein.
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The invention relates to polymers useful as a papermaking additives, The invention also relates to methods for making and using such additives.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional Patent Application No. 61/509,845, filed on Jul. 20, 2011, the contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to compositions, methods and systems having utility in numerous applications, including particularly heat transfer systems such as refrigeration systems. In preferred aspects, the present invention is directed to refrigerant compositions particularly well adapted for use in applications in which the refrigerant 1,1,1,2-tetrafluoroethane (HFC-134a) was previously and frequently used, including particularly for heating and/or cooling applications, and to retrofitting refrigerant and/or air conditioning systems, including systems designed for use with HFC-134a.
BACKGROUND
[0003] During the course of the past several years, substantial effort has been devoted to developing more environmentally friendly alternatives to materials which had previously been frequently used for refrigeration and air conditioning purposes. During this time, the main refrigerant used for mobile air conditioning (MAC) systems had been HFC-134a. Although HFC-134a possesses many properties that make it attractive for use in MAC systems, it has a relatively high global warming potential (GWP) of about 1430 (100 years).
[0004] The fluorinated olefin HFO-1234yf has emerged after much research and development effort by the assignee of the present invention as the material of choice to replace HFC-134a in MAC systems. The emergence of HFO-1234yf as the next-generation material of choice for MAC systems is due primarily to its exceptional ability to provide a combination of difficult to achieve properties, such as excellent heat transfer characteristics, low toxicity, low flammability, and chemical stability, among other properties. Furthermore, HFO-1234yf is capable of providing this combination of properties with little or no need to be blended with other materials.
[0005] Prior to and subsequent to the development of HFO-1234yf, much of the effort directed toward next-generation refrigerants was focused on the development of heat transfer compositions comprised of a blend or mixture of two or more components. However, these efforts have thus far been generally less than fully successful because of a failure to fully realize one or more of the myriad of properties required for a successful next generation refrigerant.
[0006] The fluorinated olefin 1,3,3,3-tetrafluoropropene (HFO-1234ze) has also been identified in an application assigned to the assignee of the present invention as a next generation refrigerant due to its advantageous combination of properties. See, for example, WO 2009/089511. However, while this application discloses that HFO-1234ze is very attractive as a refrigerant in many applications, it also reveals that it has a substantially lower capacity relative to HFC-134a than does HFO-1234yf in certain air conditioning applications when each is used as the sole refrigerant.
[0007] Fluorinated olefin blends, such as those including HFO-1234yf or HFO-1234ze, have been suggested for use in a wide variety of applications, including heat transfer compositions. For example, WO 2009/089511, also discloses blends comprising as a first component one or more fluorinated olefins according to a particular structure and a second component selected from a list of compounds comprising chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs), water and CO2. However, the specific combination of components in the particular concentration ranges required by the present invention are not disclosed, and no particular combination of these components is identified in WO 2009/089511 as having the advantageous and beneficial properties described herein.
[0008] US Application No. 2010/0044619, which is also assigned to the assignee of the present invention, also discloses blends comprising fluorinated olefins for use in connection with heat transfer compositions. This application describes blends comprising as a first component dichloromethane (HFC-32), second component comprising multi-fluorinated olefins having from 2 to 5 carbon atoms, and optionally a third component selected from fluorinated alkanes having to 2 to 3 carbon atoms, CF3I, and combinations of these. According to this application, the second and/or third component of the blend is incorporated for the purpose of acting as of an agent for reducing the flammability of the material relative to HFC-32 alone. Once again, however, the specific combination of components in the particular concentration ranges required by the present invention are not disclosed, and no particular combination of these components is identified in US Application No. 2010/0044619 as having the advantageous and beneficial properties described herein.
[0009] Although it is believed that the blends of materials disclosed in the above-noted applications are generally acceptable for use in heat transfer applications under certain circumstances, applicants have found that unexpected yet highly beneficial advantages can be achieved by careful selection of materials within a specific concentration range for forming a heat transfer composition blend which is at once capable of achieving highly desirable and unexpected heat transfer properties, extraordinarily beneficial environmental properties and nonhazardous compositions from the standpoint of combustion ignition.
[0010] The burning velocity of a material is one measure that has heretofore been used to assess the hazardousness of the material from a flammability or explosive nature stand point. Thus it has heretofore been considered in many application that a material having a burning velocity below a value of 10 (measured as described hereinafter), is not only important or essential for many applications, but also that such a material would be considered generally a non-hazardous material from a flammability or explosive nature stand point. In this regard it is noted that HFO-1234ze has a burning velocity of about 0, which is nearly the same as the burning velocity of HFC-32, and therefore there would be no real advantage or reason to form a combination of these material according to the above-noted disclosures.
SUMMARY
[0011] Applicants have found that heat transfer compositions having highly desirable heat transfer properties (including excellent and unexpectedly peak efficiency (COP)), environmental properties (particularly a GWP of less than about 100) and a low level of hazardousness from the stand point of flammability/combustion impact. More specifically, applicants have found that great but unexpected advantages can be achieved by the use of compositions comprising HFO-1234ze, preferably transHFO-1234ze, in amounts of from greater than about 86% to about 95%, and HFC-32 in amounts of from about 5% to less than about 14% by weight. One unexpected advantage of the preferred aspects of the present invention is that an unexpectedly high peak efficiency occurs with HFC-32 concentrations of less than about 14%. This result is not predicted using current standard simulation techniques and, at present, applicants do not have an explanation for the reason for this result. Applicants have also observed, quite unexpectedly, that the capacity of the compositions tend to not substantially increase for HFC-32 concentrations that are greater than about 14% by weight. This is also an unexpected advantage, especially in stationary systems insofar as excess capacity can cause an overload in electric motors, and especially in automotive air conditioning systems insofar as excess capacity can cause a negative impact on the available power from the car's engine. As used herein unless otherwise indicated, concentrations and weight percentages are based upon the total amount of HFO-1234ze and HFC-32 in the non-lubricant components of the composition. In certain preferred embodiments, the non-lubricant components of the heat transfer composition, sometimes also referred to herein as the refrigerant, consist essentially of HFO-1234ze and HFC-32 in the amounts described herein.
[0012] In preferred aspects, the heat transfer compositions, methods, uses and systems of the present invention comprise or utilize a multi-component mixture comprising: (a) from about 86% to about 95% by weight of HFO-1234ze, preferably transHFO-1234ze (also referred to as HFO-1234ze(E)); and (b) from about 5% to less than about 14% by weight of HFC-32, and (c) optionally minor amounts of other components to fine-tune one or more of the properties of the heat transfer composition. Unless otherwise indicated, weight percentages are based upon weight percent based on the total amount of components (a), (b) and (c) present in the composition.
[0013] In certain, generally less preferred embodiments in which efficiency is of not such a great concern, the heat transfer compositions, methods, uses and systems of the present invention comprise or utilize a multi-component composition comprising: (a) from about 80% to about 95% by weight of HFO-1234ze, preferably transHFO-1234ze HFO-1234ze and (b) from about 5% to about 20% by weight of HFC-32. In such embodiments, as well as in the more preferred embodiments, applicants have found that the relative amounts of each component (a) and (b) in the composition is effective to provide said composition with a GWP (as hereinafter defined) of not greater than 150, and even more preferably not greater than about 100, while maintaining an ignition hazard level (as hereinafter defined) of not greater than about 5, even more preferably not greater than about 2, and even more preferably of about 0. In such embodiments it is also generally preferred that the composition has a burning velocity (as hereinafter defined) of not greater than about 2.
[0014] In certain preferred embodiments, the compositions of the present invention have a relative amount of each component (a)-(c) effective to provide said composition with a capacity relative to HFC-134a under MAC conditions (as hereinafter defined) of from about 90% to about 105%, and even more preferably from about 95% to about 101%, and a COP relative to HDC-134a under MAC condition (as hereinafter defined) for from about 98% to about 102%, more preferably of about 100%.
[0015] In certain preferred embodiments, the compositions of the present invention have a relative amount of each component (a)-(c) effective to provide said composition with a Evaporator Glide (as hereinafter defined) of not greater than about 12 and even more preferably not greater than about 10.
[0016] In certain highly preferred embodiments, the present invention comprises or utilizes a multi-component composition comprising: (a) HFO-1234ze, preferably transHFO-1234ze; and (b) HFC-32, with the relative amount of each component (a)-(b) in the composition being effective to provide said composition with: (i) a GWP (as hereinafter defined) of not greater than 150, and even more preferably not greater than about 100; (ii) an ignition hazard level (as hereinafter defined) of not greater than about 7, even more preferably not greater than about 5, and even more preferably not greater than about 2; (iii) a capacity relative to HFC-134a under MAC conditions (as hereinafter defined) of from about 90% to about 105%, and even more preferably from about 95% to about 101%; (iv) a COP relative to HFC-134a under MAC condition (as hereinafter defined) for from about 98% to about 102%, more preferably of about 100%; and (v) a Evaporator Glide (as hereinafter defined) of not greater than about 12, and even more preferably not greater than about 10.
[0017] The present invention provides also methods and systems which utilize the compositions of the present invention, including methods and systems for heat transfer and for retrofitting existing heat transfer systems. Certain preferred method aspects of the present invention relate to methods of providing cooling in small refrigeration systems. Other method aspects of the present invention provide methods of retrofitting an existing small refrigeration system designed to contain or containing R-134a refrigerant comprising introducing a composition of the present invention into the system without substantial engineering modification of said existing refrigeration system. According to certain highly preferred aspects of the present invention, the refrigeration system and/or refrigeration methods and/or the refrigerant compositions of the present invention are directed to mobile air conditioning systems, and even more preferably automotive air conditioning systems, and even more preferably air-conditioning systems contained in or used in connection with passenger cars.
[0018] The term HFO-1234ze is used herein generically to refer to 1,1,1,3-tetrafluoropropene, independent of whether it is the cis- or trans-form. The terms “cisHFO-1234ze” and “transHFO-1234ze” are used herein to describe the cis- and trans-forms of 1, 1, 1, 3-tetrafluoropropene respectively. The term “HFO-1234ze” therefore includes within its scope cisHFO-1234ze, transHFO-1234ze, and all combinations and mixtures of these.
BRIEF DESCRIPTION OF THE FIGURES
[0019] FIG. 1 illustrates a schematic depiction of the experimental setup for testing of tubular heaters.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Small refrigeration systems are important in many applications, as mentioned above. In such systems, and in automotive air conditioning, one refrigerant which has been commonly used is HFC-134a, which has an estimated Global Warming Potential (GWP) of 1430. Applicants have found that the compositions of the present invention satisfy in an exceptional and unexpected way the need for alternatives and/or replacements for refrigerants in such applications, particularly and preferably HFC-134a, that at once have lower GWP values and provide non-flammable, non-toxic fluids that have a close match in cooling capacity and/or efficiency (and preferably both) to HFC-134a in such systems. Applicants have found that the compositions of the present invention satisfy in an exceptional and unexpected way the need for new compositions, especially for small and medium refrigeration applications, having improved performance with respect to environmental impact while at the same time providing other important performance characteristics, such as capacity, efficiency, flammability and toxicity. In preferred embodiments the present compositions provide alternatives and/or replacements for refrigerants currently used in these applications, including in automobile air conditioning, particularly and preferably HFC-134a, that at once have lower GWP values and provide a refrigerant composition that has a low degree of hazardousness, as defined hereinafter.
Heat Transfer Compositions
[0021] The compositions of the present invention are generally adaptable for use in heat transfer applications, that is, as a heating and/or cooling medium, but are particularly well adapted for use, as mentioned above, in low and medium temperature refrigeration systems, and in automotive AC systems, that have heretofore used HFC-134a.
[0022] Applicants have found that use of the components of the present invention within the stated ranges is important to achieving the highly advantageous combinations of properties exhibited by the present compositions, particularly in the preferred systems and methods, and that use of these same components but substantially outside of the identified ranges can have a deleterious effect on one or more of the important properties of the compositions of the invention.
[0023] As mentioned above, the preferred compositions exhibit a degree of hazard value of not greater than about 5. As used herein, degree of hazardousness is measured by observing the results of a cube test using the composition in question and applying a value to that test as indicated by the guidelines provided in the following table below:
[0000]
HAZARD VALUE GUIDELINE TABLE
HAZARD VALUE
TEST RESULT
RANGE
No ignition. Exemplary of this hazard level
0
are the pure materials R-134a and
transHFO-1234ze.
Incomplete burning process and little or no
1-2
energy imparted to indicator balls and no
substantial pressure rise in the cube (all
balls rise an amount that is barely
observable or not all from the cube holes
and essentially no movement of the cube
observed). Exemplary of this hazard level
is the pure material HFO-1234yf, with a
value of 2.
Substantially complete burning process
3-5
and low amount of energy imparted to
some of the balls and substantially no
pressure rise in the cube (some balls rise
an observable small distance and return to
the starting position, and essentially no
movement of the cube observed).
Exemplary of this hazard level is the pure
material R-32, with a value of 4.
Substantially complete burning process
6-7
and substantial amount of energy imparted
to most balls and high pressure rise in the
cube but little or no movement of the cube
(most balls rise an observable distance
and do not return to the top of the cube,
but little or no movement of the cube
observed).
High Hazard Conditions—Rapid burning
8-10
and substantial imparted to all balls and
substantial energy imparted to the cube
(substantially all balls rise from the cube
and do not return to the starting position,
and substantial movement of the cube
observed). Exemplary of this hazard level
are the pure materials R-152a and R-
600a, with values of 8 and 10 respectively.
[0024] The cube test is conducted as indicated in the Examples below. As mentioned above, applicants have found that the compositions of the present invention are capable of achieving a difficult combination of properties, including particularly: low GWP; excellent capacity relative to HFC-134a; excellent efficiency relative to HFC-134a; an evaporator condition glide of less than about 12; and a hazard value of not greater than 7, and preferably of about 3 or less.
[0025] The refrigerant compositions of the present invention may be incorporated into heat transfer compositions which include not only the refrigerant having the required and optional components for the refrigerant, but which also includes other components for the purpose of enhancing or providing certain functionality to the composition, or in some cases to reduce the cost of the composition. For example, heat transfer compositions according to the present invention, especially those used in vapor compression systems, include in addition to components (a)-(c) as mentioned above, but also a lubricant, generally in amounts of from about 30 to about 50 percent by weight of the composition, based on the total of the refrigerant composition and the lubricant, and in some cases potentially in amount greater than about 50 percent and other cases in amounts as low as about 5 percent by weight.
[0026] Commonly used refrigeration lubricants such as Polyol Esters (POEs) and Poly Alkylene Glycols (PAGs), PAG oils, silicone oil, mineral oil, alkyl benzenes (ABs) and poly(alpha-olefin) (PAO) that are used in refrigeration machinery with hydrofluorocarbon (HFC) refrigerants may be used with the refrigerant compositions of the present invention. Commercially available mineral oils include Witco LP 250 (registered trademark) from Witco, Zerol 300 (registered trademark) from Shrieve Chemical, Sunisco 3GS from Witco, and Calumet R015 from Calumet. Commercially available alkyl benzene lubricants include Zerol 150 (registered trademark). Commercially available esters include neopentyl glycol dipelargonate, which is available as Emery 2917 (registered trademark) and Hatcol 2370 (registered trademark). Other useful esters include phosphate esters, dibasic acid esters, and fluoroesters. In some cases, hydrocarbon based oils are have sufficient solubility with the refrigerant that is comprised of an iodocarbon, the combination of the iodocarbon and the hydrocarbon oil might more stable than other types of lubricant. Such combination may therefore be advantageous. Preferred lubricants include polyalkylene glycols and esters. Polyalkylene glycols are highly preferred in certain embodiments because they are currently in use in particular applications such as mobile air-conditioning. Of course, different mixtures of different types of lubricants may be used.
Heat Transfer Methods and Systems
[0027] The present methods, systems and compositions are thus adaptable for use in connection with a wide variety of heat transfer systems in general and refrigeration systems in particular, such as air-conditioning (including both stationary and mobile air conditioning systems), refrigeration, heat-pump systems, and the like. In certain preferred embodiments, the compositions of the present invention are used in refrigeration systems originally designed for use with an HFC refrigerant, such as, for example, R-134a. The preferred compositions of the present invention tend to exhibit many of the desirable characteristics of R-134a but have a GWP that is substantially lower than that of R-134a while at the same time having a capacity and/or efficiency (as measured by COP) that is substantially similar to or substantially matches, and preferably is as high as or higher than R-134a. In particular, applicants have recognized that certain preferred embodiments of the present compositions tend to exhibit relatively low global warming potentials (“GWPs”), preferably less than about 150, and more preferably not greater than about 100, while at the same time achieving a hazard value of less than about 5, and even more preferably of not greater than about 2.
[0028] As mentioned above, the present invention achieves exceptional advantage in connection with systems known as low temperature refrigeration systems. As used herein the term “low temperature refrigeration system” refers to vapor compression refrigeration systems which utilize one or more compressors and a condenser temperature of from about 35° C. to about 75° C. In preferred embodiments, the systems have an evaporator temperature of from about 10° C. to about −35° C., with an evaporator temperature preferably of about −10° C. Moreover, in preferred embodiments, the systems have a degree of superheat at evaporator outlet of from about 0° C. to about 10° C., with a degree of superheat at evaporator outlet preferably of from about 4° C. to about 6° C. Furthermore, in preferred embodiments of such systems, the systems have a degree of superheat in the suction line of from about 1° C. to about 15° C., with a degree of superheat in the suction line preferably of from about 5° C. to about 10° C.
[0029] Another preferred system of the present invention is referred to herein as a “automotive AC or MAC systems.” Such systems have an evaporator temperature of from about 0° C. to about 20° C. and a CT of from about 30° C. to about 95° C. Moreover, in preferred embodiments of such systems, the systems have a degree of superheat at evaporator outlet of from about 2° C. to about 10° C., with a degree of superheat at evaporator outlet preferably of from about 4° C. to about 7° C. Furthermore, in preferred embodiments of such systems, the systems have an increase of temperature in the suction line of from about 0.5° C. to about 5° C., with an increase of temperature in the suction line preferably of from about 1° C. to about 3° C.
[0030] As mentioned above, the present invention also achieves exceptional advantage in connection with systems known as medium temperature refrigeration systems. As used herein the term “medium temperature refrigeration system” refers to vapor compression refrigeration systems which utilize one or more compressors and a condenser temperature of from about 35° C. to about 75° C. In preferred embodiments, the systems have an evaporator temperature of from about 10° C. to about −35° C., with an evaporator temperature preferably of about −10° C. Moreover, in preferred embodiments, the systems have a degree of superheat at evaporator outlet of from about 0° C. to about 10° C., with a degree of superheat at evaporator outlet preferably of from about 4° C. to about 6° C. Furthermore, in preferred embodiments, the systems have a degree of superheat in the suction line of from about 1° C. to about 15° C., with a degree of superheat in the suction line preferably of from about 5° C. to about 10° C.
EXAMPLES
[0031] The following examples are provided for the purpose of illustrating the present invention but without limiting the scope thereof.
Compositions Tested
[0032] The following compositions within the scope of the present invention are the utilized in the examples which follow:
[0000]
COMPOSITION
wt % transHFO-
DESIGNATION
1234ze
Wt % HFC-32
A1
94
6
A2
90
10
A3
86
14
A4
82
18
C1
78
22
C2
74
26
Example 1
Auto AC Conditions
Experimental Cop and Capacity
[0033] This example illustrates the COP and capacity performance of embodiments A1-A3 of the present invention when used as a replacement for HFC-134a in a auto AC refrigerant systems. The coefficient of performance (COP) is a universally accepted measure of refrigerant performance, especially useful in representing the relative thermodynamic efficiency of a refrigerant in a specific heating or cooling cycle involving evaporation or condensation of the refrigerant. In refrigeration engineering, this term expresses the ratio of useful refrigeration to the energy applied by the compressor in compressing the vapor. The capacity of a refrigerant represents the amount of cooling or heating it provides and provides some measure of the capability of a compressor to pump quantities of heat for a given volumetric flow rate of refrigerant. In other words, given a specific compressor, a refrigerant with a higher capacity will deliver more cooling or heating power. One means for estimating COP of a refrigerant at specific operating conditions is from the thermodynamic properties of the refrigerant using standard refrigeration cycle analysis techniques (see for example, R. C. Downing, FLUOROCARBON REFRIGERANTS HANDBOOK, Chapter 3, Prentice-Hall, 1988). and tested in accordance with SAE Standard J2765 OCT2008, Issued 2008-10, a copy of which is attached hereto and incorporated herein by reference. The results for 145, L45, M45, H45, 150, 135, L35, M35, H35 and Charge as defined in SAE Standard J2765 OCT2008 are reported below. The testing reported below began at the lower condenser temperatures but did not produce reportable results at the higher condenser temperature conditions for HFC-32 concentrations of 14% because of difficulty with excessive frost formation, which made the system unstable and difficult to acquire reliable data. Although the condenser temperature conditions described in J2765 are important for the design of MAC systems, the substantial and unexpected deterioration in efficiency at the tested condenser temperatures reported below was sufficient to establish the unexpected result in efficiency peak described herein.
[0000]
COP (kW/kW)
Refrigerant
Test
R134a
R32/R1234ze
R32/R1234ze
R32/R1234ze
Condition
baseline
6%/94%
10%/90%
14%/86%
I45
2.32
2.09
2.27
NA
L45
1.63
1.54
1.65
NA
M45
1.49
1.40
1.49
NA
H45
1.13
1.07
1.17
NA
I50
2.17
2.02
2.06
1.98
I35
3.09
2.92
3.11
2.78
L35
2.06
2.06
2.16
1.95
M35
1.82
1.80
1.88
1.75
H35
1.40
1.37
1.44
1.39
Charge
2.10
2.05
2.15
2.03
* NA—Not Available
[0000]
Capacity (kW)
Refrigerant
Test
R134a
R32/R1234ze
R32/R1234ze
R32/R1234ze
Condition
baseline
6%/94%
10%/90%
14%/86%
I45
3.01
2.40
2.72
NA
L45
3.88
3.30
3.62
NA
M45
4.44
3.74
4.12
NA
H45
4.76
4.03
4.47
NA
I50
3.14
2.59
2.74
2.90
I35
3.84
3.17
3.57
3.56
L35
4.95
4.39
4.78
4.77
M35
5.58
4.98
5.31
5.39
H35
6.12
5.43
5.71
5.99
Charge
5.91
5.15
5.56
5.68
* NA—Not Available
[0034] As can be seen from the results reported above, COP peaks at an HFC-32 concentration of above about 10% and below about 14%. This result is contrary to expectations based on using standard refrigeration cycle analysis predictive techniques.
Example 2
Auto AC Conditions—GWP and Hazard Value
[0035] By way of non-limiting example, the following Table A illustrates the substantial GWP superiority and hazard avoidance advantage of certain compositions of the present invention, which are described in parenthesis in terms of weight fraction of each component, in comparison to the GWP of HFC-134a, which has a GWP of 1430 and to compositions outside the scope of the present invention (C1 and C2).
[0000]
TABLE A
HAZARD
BV
Group
#
Composition
GWP
VALUE
cm/s
32 + 1234ze
A1
R32/1234ze(E)(0.06/0.94)
46
1
0.4
A2
R32/1234ze(E)(0.1/0.90)
73
2
0.7
A3
R32/1234ze(E)(0.14/0.86)
100
2
0.9
32 + 1234ze
A4
R32/1234ze(E)(0.18/0.82)
126
2
1.2
C1
R32/1234ze(E)(0.22/0.78)
153
2
1.5
C2
R32/1234ze(E)(0.26/0.74)
180
2
1.7
[0036] Burning velocity (BV) is determined using standard techniques.
[0037] The Hazard Value is determined as described above using the Cube Test. The Cube Test is performed pursuant to the procedure described herein. Specifically, each material being tested is separately released into a transparent cube chamber which has an internal volume of 1 ft3. A low power fan is used to mix components. An electrical spark with enough energy to ignite the test fluids is used. The results of all tests are recorded using a video camera. The cube is filled with the composition being tested so as to ensure a stoichiometric concentration for each refrigerant tested. The fan is used to mix the components. Effort is made to ignite the fluid using the spark generator for 1 min. Record the test using HD camcorder
[0038] A schematic of the experimental setup for testing of tubular heaters is illustrated in FIG. 1 .
|
Heat transfer compositions, methods and use wherein the composition comprising: (a) from about 5 to about 20% by weight of HFC-32 and (b) from about 80% to about 95% by weight of HFO-1234ze.
| 2
|
RELATED APPLICATIONS
This application claims priority to Chinese Patent Application Serial Number 201420499922.7, filed on Sep. 2, 2014. The entirety of the aforementioned application is hereby incorporated by reference and made a part of this specification.
BACKGROUND
Field of Invention
The present invention is related to a female connector, and more particularly, to a large current female connector for high-speed transmission.
Description of Related Art
With the popularity of the large-screen mobile terminal, the accompanying high power consumption has become an urgent issue that people have to address. To solve this problem, high-capacity batteries are developed, but the charging current for a high-capacity battery is limited by the USB connector. The dimension of a standard power terminal cannot be changed, and thus the standard power terminal can only carry limited current. The higher the electric capacity of a battery is, the longer the charging time is required. China Patent reference CN102709723 A discloses a USB connector capable of carrying higher current, the USB connector includes a power terminal, in which the USB connector further includes an assistant power terminal. The power terminal and the assistant power terminal are configured to be simultaneously in electrical contact with a power terminal of a mating USB connector.
In the aforementioned USB connector, an assistant power terminal is added. Consequently, in the process of fabricating the USB connector capable of carrying higher current, the original mold of terminal group has to be changed, and the amount of material for making the power terminal increases. The fabrication process becomes more complicated, and the cost is accordingly enhanced. In sum, the addition of a power terminal increases the consumption of manpower and material resources.
SUMMARY
In regard to the aforementioned issues, it is an object of the present invention to provide a large current female connector for high-speed transmission which can be fabricated without changing the mold, is capable of carrying large current, and cost effective.
The technical solution of the present invention is to design a large current female connector for high-speed transmission, the female connector including a case, an insulating body, and an upper terminal group and a lower terminal group disposed in the insulating body. The insulating body is disposed in the case. A power terminal in the upper terminal group and a corresponding power terminal in the lower terminal group are connected to form a big power terminal, wherein an insulating body trench for accommodating the big power terminal is disposed on the insulating body.
As a further improvement to the aforementioned technical solution, the insulating body includes an upper insulating body, a middle insulating body and a lower insulating body. The upper terminal group is disposed on the upper insulating body. The lower terminal group is disposed on the lower insulating body. The upper insulating body and the lower insulating body are engaged with the middle insulating body to form an integrated device.
As a further improvement to the aforementioned technical solution, a shielding sheet is further included, wherein a shielding sheet trench for accommodating the big power terminal is disposed on the shielding sheet. The shielding sheet is disposed in the middle insulating body.
As a further improvement to the aforementioned technical solution, the insulating body includes an upper insulating body and a lower insulating body, wherein the upper terminal group is disposed on the upper insulating body, and the lower terminal group is disposed on the lower insulating body.
As a further improvement to the aforementioned technical solution, a shielding sheet is further included. A shielding sheet trench for accommodating the big power terminal is disposed on the shielding sheet, wherein the shielding sheet is disposed between the upper insulating body and the lower insulating body. The upper insulating body and the lower insulating body are engaged to form an integrated device.
As a further improvement to the aforementioned technical solution, a shielding sheet is further included, wherein a shielding sheet trench for accommodating the big power terminal is disposed on the shielding sheet. The insulating body is integrally formed, and the shielding sheet is inserted into the insulating body.
As a further improvement to the aforementioned technical solution, the shielding sheet further includes an upper spring plate and a lower spring plate, wherein the upper spring plate is physically and electrically connected to the upper ground terminal located at an upper layer of the insulating body, and the lower spring plate is physically and electrically connected to the lower ground terminal located at a lower layer of the insulating body.
As a further improvement to the aforementioned technical solution, the shielding sheet includes an upper spring plate and a lower spring plate, wherein the upper spring plate is physically and electrically connected to the upper ground terminal located at the upper insulating body, and the lower spring plate is physically and electrically connected to the lower ground terminal located at the lower insulating body.
As a further improvement to the aforementioned technical solution, a first shielding engaging case and a second shielding engaging case are further included. A first hook is disposed on the first shielding engaging case. A second hook is disposed on the second shielding engaging case. A first hooking portion and a second hooking portion are disposed on the upper surface and the lower surface of the middle insulating body, respectively. The first shielding engaging case is engaged with the upper surface of the middle insulating body, wherein the first hook is interlocked with the corresponding second hooking portion on the middle insulating body. The second shielding engaging case is engaged with the lower surface of the middle insulating body, wherein the second hook is interlocked with the corresponding first hooking portion on the middle insulating body.
As a further improvement to the aforementioned technical solution, the upper terminal group and/or the lower terminal group at least includes a high frequency terminal pair, wherein the thickness of a contact portion of the high frequency terminal pair is smaller than the thickness of a portion adjacent to the contact portion.
In the present invention, the connector has a structure in which a power terminal in the upper terminal group and a corresponding power terminal in the lower terminal group are connected to form a big power terminal, and an insulating body trench for accommodating the big power terminal is disposed on the insulating body. One power terminal can carry only a limited amount of current, while a grand terminal combining two power terminals can carry much more current. Therefore, as a power terminal in the upper terminal group and a corresponding power terminal in the lower terminal group are connected together, the current capacity of the big power terminal combining two power terminals increases significantly. A large current carrying connector can thus be realized. The charging speed of a battery with high electrical capacity can thus be accelerated. Therefore, the present invention has advantages in that the fabrication process is simple and cost effective, and a large current transport is possible.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows:
FIG. 1 is a schematic exploded view of an embodiment;
FIG. 2 is a schematic diagram of a structure built up by the components of FIG. 1 ;
FIG. 3 is a schematic structure diagram of the big power terminal of FIG. 1 ;
FIG. 4 is a schematic structure diagram of the upper terminal group lower terminal group of FIG. 1 ;
FIG. 5 is a schematic structure diagram of the high frequency terminal pairs of FIG. 4 ; and
FIG. 6 is an enlarged schematic diagram of the portion A of FIG. 5 .
DETAILED DESCRIPTION
In the description of the present invention, it should be noticed, orientation or position relation indicated by terms such as “at the center of,” “on,” “below,” “in front of,” “behind,” “at the left of,” “at the right of” are orientation or position relation in connection with the figures. These terms are used to simplify the description of the present invention, and are not intended to indicate or suggest a specific configuration or orientation in operation for the device or element being described. Therefore, these terms cannot be construed as limitations to the present invention. In addition, terms such as “first” and “second” are used for descriptive purpose and shall not be construed as indicating or suggesting an element is more significant than another.
In the description of the present invention, it should be noticed, unless otherwise specified, terms such as “mounted,” “joined,” and “connected” should be construed in their broad sense. For example, “connected” includes “fixedly connected,” “detachably connected,” or “integrally connected”; it also includes “mechanically connected” or “electrically connected”; it further includes “directly connected,” “connected via an intermediate element,” or implies the inner connection of two elements. The meaning of each of these terms in the present invention shall be construed by the persons having ordinary skills in the art based on the specific context. In addition, unless otherwise specified, in the description of the present invention, “a plurality of,” or “several” means two or more than two.
FIG. 1 to FIG. 6 disclose a first embodiment of a large current female connector for high-speed transmission. Referring to FIG. 1 to FIG. 3 first, the insulating body includes an upper insulating body 21 , a middle insulating body 23 , a lower insulating body 22 , an upper terminal group 31 disposed on the upper insulating body 21 , and a lower terminal group 32 disposed on the lower insulating body 22 . The corresponding two power terminals in the upper terminal group 31 and the lower terminal group 32 are connected to form a big power terminal 4 . Insulating body trenches 5 are disposed respectively on the upper insulating body 21 , the middle insulating body 23 , and the lower insulating body 22 . When the upper terminal group 31 is disposed on the upper insulating body 21 and the lower terminal group 32 is disposed on the lower insulating body 22 , the big power terminals 4 are disposed correspondingly in the insulating body trench 5 on the upper insulating body 21 and in the insulating body trench 5 on the lower insulating body 22 . When the upper insulating body 21 and the lower insulating body 22 are engaged with the middle insulating body 23 , the big power terminal 4 should be correspondingly disposed in the insulating body trench 5 formed from the middle insulating body 23 . Then the upper insulating body 21 , the middle insulating body 23 , and the lower insulating body 22 are engaged tightly to form an integrated device. Then the integrated device is mounted in the case 1 . A rib 11 is disposed on the case 1 . The rib 11 makes the case 1 more robust, preventing the dovetail connection from being popped out. The case 1 further includes a welding foot 12 so as to mount the connector on a PCB. Therefore, as the corresponding two power terminals in the upper terminal group 31 and the lower terminal group 32 are connected together, the current capacity of the big power terminal 4 combining two power terminals increases significantly. A large current carrying connector can thus be realized. The charging speed of a battery with high electrical capacity can thus be accelerated.
To achieve the high frequency transmission of the terminal group, the upper terminal group 31 and/or the lower terminal group 32 at least includes a high frequency terminal pair 312 . The thickness of the contact portion 3121 of the high frequency terminal pair 312 is smaller than the thickness of the portion 3122 adjacent to the contact portion 3121 (as shown in FIG. 4 to FIG. 6 ).
To reduce the signal interference between the upper and lower terminal groups, a shielding sheet 7 is further included. A shielding sheet trench 6 for accommodating the big power terminal 4 is disposed on the shielding sheet 7 . The shielding sheet 7 is disposed in the middle insulating body 23 . When the upper insulating body 21 and the lower insulating body 22 are engaged with the middle insulating body 23 , the big power terminal 4 is correspondingly disposed in the insulating body trenches 5 and simultaneously disposed in the corresponding shielding sheet trench 6 .
To improve the shielding effect of the shielding sheet, the shielding sheet 7 includes an upper spring plate 71 and a lower spring plate 72 . The upper spring plate 71 is physically and electrically connected to the upper ground terminal 311 disposed on the upper insulating body 21 . The lower spring plate 72 is physically and electrically connected to the lower ground terminal 321 disposed on the lower insulating body 22 .
To improve the engagement between the upper insulating body 21 and the lower insulating body 22 , a first shielding engaging case 81 and a second shielding engaging case 82 are further included. A first hook 811 is disposed on the first shielding engaging case 81 . A second hook 821 is disposed on the second shielding engaging case 82 . Meanwhile, a first hooking portion 231 and a second hooking portion 232 are disposed on the upper surface and the lower surface of the middle insulating body 23 , respectively. The first shielding engaging case 81 is engaged with the upper surface of the middle insulating body 23 , wherein the first hook 811 is interlocked with the corresponding second hooking portion 232 on the middle insulating body. Then, the second shielding engaging case 82 is engaged with the lower surface of the middle insulating body 23 , wherein the second hook 821 is interlocked with the corresponding first hooking portion 231 on the middle insulating body 23 .
The present invention can be implemented as a second embodiment (not shown in the figures). The second embodiment is essentially the same as the first embodiment, except that the insulating body includes an upper insulating body and a lower insulating body, in which the upper terminal group is disposed on the upper insulating body, and the lower terminal group is disposed on the lower insulating body. Insulating body trenches are disposed respectively on the upper insulating body and the lower insulating body. When the upper terminal group is disposed on the upper insulating body and the lower terminal group is disposed on the lower insulating body, the big power terminal is disposed correspondingly in the insulating body trench on the upper insulating body and in the insulating body trench on the lower insulating body. The upper insulating body and the lower insulating body are engaged with each other to form an integrated device.
To reduce the signal interference between the upper and lower terminal groups, a shielding sheet is further included. A shielding sheet trench for accommodating the big power terminal is disposed on the shielding sheet. The shielding sheet is disposed between the upper insulating body and the lower insulating body. When the upper terminal group is disposed on the upper insulating body and the lower terminal group is disposed on the lower insulating body, the big power terminal is correspondingly disposed in the insulating body trenches and simultaneously disposed in the corresponding shielding sheet trench.
The present invention can be implemented as a third embodiment (not shown in the figures). The third embodiment is essentially the same as the first embodiment, except that the insulating body is integrally formed. The upper terminal group and the lower terminal group are disposed on the insulating body. An insulating body trench for accommodating the big power terminal is disposed on the insulating body. When the upper terminal group and the lower terminal group are disposed in the insulating body, the big power terminal is disposed correspondingly in the insulating body trench. The insulating body is then disposed into the case.
To reduce the signal interference between the terminal groups, a shielding sheet is further included. The shielding sheet is inserted in the insulating body in advance. A shielding sheet trench for accommodating the big power terminal is disposed on the shielding sheet. When the upper terminal group and the lower terminal group are disposed in the insulating body, the big power terminal is correspondingly disposed in the insulating body trench and simultaneously disposed in the corresponding shielding sheet trench.
To improve the shielding effect of the shielding sheet, the shielding sheet includes an upper spring plate and a lower spring plate. The upper spring plate is physically and electrically connected to the upper ground terminal located at an upper layer of the insulating body, and the lower spring plate is physically and electrically connected to the lower ground terminal located at a lower layer of the insulating body.
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Provided is a large current female connector for high-speed transmission, comprising a case, an insulating body, and an upper terminal group and a lower terminal group disposed in the insulating body. The insulating body is disposed in the case. A power terminal in the upper terminal group and a corresponding power terminal in the lower terminal group are connected to form a big power terminal. An insulating body trench for accommodating the big power terminal is disposed on the insulating body. The present invention has advantages in that the fabrication process is simple and cost effective, and a large current transport is possible.
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FIELD OF THE INVENTION AND RELATED ART
The present invention relates to an (electro-)luminescence device utilized in copying machines, printers and display apparatus, e.g., as a backlight device for a display apparatus and a light source for illuminating an original in an image-reading apparatus.
Hitherto, as light-emission devices for converting applied electricity into light, there have been used, e.g., tubes and bulbs, such as incandescent lamps utilizing light emission caused by resistance heating and fluorescent tubes utilizing light emission caused by discharge in dilute gas, and semiconductor devices, such as light-emitting diodes (LED) utilizing light-emission caused by recombination of electrons and holes at pn-junctions formed in organic crystals. As indoor or outdoor illumination light sources, the tubes and bulbs have been most frequently used, but LEDs have been frequently used as indicators for various electronic appliances. Furthermore, recently, liquid crystal display apparatus equipped with fluorescent lamps as a backlight have been used as a display device for computers and portable display terminals. In addition to such usages directly exposed to human eyes, there have been frequently used functional devices, such as light sources for illuminating originals in image reading apparatus for facsimile apparatus and image scanners, and photo-writing heads in LED printers.
These light source devices have their own advantages and disadvantageous depending on their types. For example, the tubes and bulbs are suitable for emitting intense light by receiving a large electric power but are large in size and liable to be broken. Further, they are not suitable for usages requiring a high-speed responsiveness. On the other hand, LEDs can emit only relatively weak light but are advantageous in that they are small in size, have excellent reliability and have high-speed responsiveness.
While not being as popular as the above-mentioned light sources, there has been partially used an electroluminescence device wherein a thin film layer comprising a crystalline fluorescent substance is formed on a substrate by coating or vapor deposition and is supplied with an AC electric field via an insulating layer to cause luminescence. Such an electroluminescence device can be formed in a thin film on a substrate and is advantageous for usages for uniformly illuminating wide ranges or for providing a small-sized, particularly a thin, apparatus including a light source.
However, such an electroluminescence device has drawbacks that it can only emit weak light even lower than an LED and requires a difficult drive scheme requiring a relatively high AC voltage, so that it has not been a popular light source device.
On the other hand, in recent years, there has been developed an organic film luminescence device (also called an organic LED device), which is provided in a film on a substrate, provides high luminance and allows a DC drive.
FIG. 11 illustrates a representative organization (laminar structure) of such an organic LED device.
Referring to FIG. 11, an organic LED device includes a substrate 1100 , an anode 1201 comprising a transparent electrode of indium tin oxide (ITO), a hole-transporting layer 1202 comprising an organic hole-transporting material, such as an organic diamine (of, e.g., formula (1) below), an electron-transporting layer 1203 comprising an organic electron-transporting material, such as tris(8-quinolinolato)aluminum (of formula (2) below) and a cathode 1204 of a substance having a low work function such as Al and/or Hg—Ag alloy, laminated in this order.
When a voltage is applied between the anode 1201 and the cathode 1204 , holes injected from the anode 1202 to the hole-transporting layer 1202 and electrons injected from the cathode 1204 to the electron-transporting layer, are re-combined to cause luminescence.
FIG. 12 illustrates a state of luminescence occurring in the organic LED device of FIG. 11 .
Referring to FIG. 12, a portion denoted by A schematically represents the luminescence caused by recombination of holes injected to the hole-transporting layer 1202 from the anode 1201 and electrons injected to the electron-transporting layer 1203 from the cathode 1204 .
Such organic LED devices can emit various colors of luminescence, e.g., by using different organic materials for the hole-transporting layer 1202 or the electron-transporting layer 1203 , by admixing another organic material into these layers, or by inserting a luminescence layer comprising another organic material between these layers.
However, according to a conventional organic LED device, the luminescence color is determined by organic materials constituting a luminescence part, so that pixels of respectively different luminescence colors have to be formed in a usage, like a full-color display, requiring independent control of different luminescence colors.
FIG. 13 illustrates a typical organization of such an organic LED device.
Referring to FIG. 13, the organic LED device includes a substrate 1100 ; a first pixel comprising an anode (portion) 1201 comprising ITO for the first pixel, a hole-transporting layer (portion) 1202 of an aromatic diamine (of formula (1)), an electron-transporting layer/luminescence layer 1203 of tris(8-quinolinolato)aluminum (of formula (2)) and a cathode 1204 of Al or Hg—Ag alloy, etc.; and also a second pixel comprising an anode (portion) 1401 comprising ITO, a hole-transporting layer (portion) 1202 of an aromatic diamine (of formula (1)), an electron-transporting layer/luminescence layer 1203 of a mixture of tris(8-quinolinolato)aluminum complex (of formula (2)) and a fluorescent substance (of formula (3) below), and a cathode 1404 of Al or Mg—Ag alloy.
In the above-mentioned device, the first pixel emits green luminescence, and the second pixel emits red luminescence.
In the device, the respective luminescence layers 1203 , 1403 and the respective cathodes 1204 , 1404 , have to be patterned into shapes of the respective pixels. Moreover, if the cathodes 1204 and 1404 of the adjacent pixels directly contact each other, or even in a single pixel, if the cathode 1204 ( 1404 ) directly contacts the anode 1202 ( 1401 ) or the hole-transporting layer 1202 ( 1402 ), phenomena, such as crosstalk and current leakage, undesirable for the device performances, are liable to occur, so that the mutually adjacent pixels have to be formed in sufficient separation from each other.
In this case, as different luminscence colors are emitted from different pixels, different color pixels are liable to be noticeable to human eyes by a careful observation, thus providing an unsatisfactory display quality.
When such an organic LED device is used as a light source for illuminating an original in an image reading apparatus, the directively of illumination light reaching a certain point on the original can be different for respective luminescence colors due to the fact that different luminescence colors are emitted from fairly separated different pixels, so that color irregularity is liable to occur depending on the surface gloss of the original.
SUMMARY OF THE INVENTION
In view of the above-mentioned problems of the prior art, a principal object of the present invention is to provide a luminescence device, particularly an organic LED device, having a minimized difference in sites for emitting different luminescence colors.
According to the present invention, there is provided, a luminescence device, comprising a substrate, and a laminated layer structure formed on the substrate including a plurality of luminescence layers emitting different luminescence colors, and a plurality of electrodes forming at least one pair of electrodes each sandwiching an associated luminescence layer, wherein at least one of the plurality of electrodes is provided with apertures, through which a luminescence flux emitted from at least one of the luminescence layers is caused to pass.
Each of the plurality of luminescence layers may comprise one or more organic compound layers. In the luminescence device, plural layers of electrodes each belonging to different pairs of electrodes sandwiching associated luminescence layers of different luminescence colors are respectively provided with apertures of which positions and/or sizes may be at least partially different from each other. Further, each pair of electrodes sandwiching an associated luminescence layer may comprise one transparent electrode on a side closer to the substrate and the other opaque electrode provided with apertures on a side more remote from the substrate, so that the luminescence flux is emitted through the substrate.
Further, at least: one luminescence layer may be sandwiched by a pair of electrodes which are both provided with apertures of which positions and/or sizes are at least partially different from each other so that the pair of electrodes comprises one transparent electrode on a side closer to the substrate and the other opaque electrode, and luminescence light flux is emitted in a direction leaving away from the substrate.
The present invention further provides an image-reading apparatus including a luminescence device as described above as an illumination light source, and a data processing apparatus including such an image-reading apparatus as a data-reading unit.
The present invention further provides a display apparatus including a luminescence device as described above as a display unit.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1, 3 and 5 are schematic sectional views showing organization of organic LED devices according to a first, a second and a third embodiment, respectively, of the invention.
FIGS. 2, 4 and 6 are schematic sectional views illustrating luminescence states in the organic LED devices of FIGS. 1, 3 and 5 , respectively.
FIG. 7 is a partial perspective of an image-reading apparatus including an organic LED device of the second embodiment (FIG. 3) as a light source for illuminating an original.
FIG. 8 is a plan view of the organic LED device of FIG. 7 as viewed from the glass substrate side thereof.
FIG. 9 is an enlarged view of a part D shown in FIG. 8 .
FIG. 10 is an illustration of a facsimile apparatus including the image-reading apparatus of FIG. 7 .
FIG. 11 is a schematic sectional view showing a typical organization of a conventional organic LED device.
FIG. 12 is a schematic sectional view illustrating a luminescence state in the organic LED device of FIG. 11 .
FIG. 13 is a schematic sectional view showing a typical organization of a conventional organic LED including separate pixels of mutually different luminescence colors.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a laminar organization of an organic LED device according to a first embodiment of the present invention.
Referring to FIG. 1, the organic LED device includes a substrate 100 ;
a first anode 201 comprising a transparent electrode of ITO (indium tin oxide); a hole-transporting layer 202 comprising an aromatic diamine (of formula (1) above); an electron-transporting layer/luminescence layer 203 comprising tris(8-quinolinolato)aluminum complex (of formula (2) above); a first cathode 204 comprising a material having a low work function, such as Al or Mg—Ag alloy and provided with apertures 205 formed therein;
a transparent insulating layer 300 comprising, e.g., SiN or SiO 2 ;
a second anode 401 comprising a transparent electrode of ITO; a hole-transporting layer 402 comprising an aromatic diamine (of formula (1)); an electron-transporting layer/luminescence layer 403 comprising tris(8-quinolinolato)aluminum complex (of formula (2)) and a fluorescent substance (of formula (3) above); and a second cathode 404 comprising a material having a low work function such as Al or Mg—Ag alloy and provided with apertures 405 .
FIG. 2 schematically illustrates a state of luminescence occurring in the organic LED device of FIG. 1 .
Referring to FIG. 2, each portion A represents luminescence caused by recombination of holes injected to the hole-transporting layer 202 from the first anode 201 and electrons injected to the electron-transporting layer 203 from the first anode 204 . In this instance, green luminescence inherent to tris(8-quinolinolato)aluminum complex of formula (2) constituting the electron-transporting layer/luminescence layer 203 is emitted. The first cathode 204 is provided with the apertures 205 so that the luminescence is not caused at parts corresponding to the apertures 205 .
Referring further to FIG. 2, each portion B represents luminescence caused by recombination of holes injected to the hole-transporting layer 402 from the second anode 401 and electrons injected to the electron-transporting layer 403 from the second anode 404 . In this instance, rather than green luminescence inherent to tris(8-quinolinolato)aluminum complex constituting the electron-transporting layer/luminescence layer 403 , red luminescence attributable to the fluorescent substance (of formula (3)) added thereto as a dopant is predominant. The second cathode 404 is provided with the apertures 405 so that the luminescence is not caused at parts corresponding to the apertures 405 .
The red luminescence flux occurring at the portion B is transmitted through the apertures 205 formed in the first cathode 204 and emitted together with the green luminescence flux occurring at the portions A through the substrate 100 .
Accordingly, in this embodiment, pixels of different luminescence colors need not be formed at (horizontally) different positions, but different luminescence colors can be emitted from a horizontally single pixel. As a result, by sufficiently reducing the sizes of the apertures 205 and 405 , it is possible to provide an organic LED device from which different luminescence colors can be emitted from luminescence positions which are substantially free from local deviation (with a minimized positional deviation) relative to a pixel size.
Regarding the respective luminescence colors, the green luminescence is caused by a voltage applied between the first anode 201 and the first cathode 204 , and the red luminescence is caused by a voltage applied between the second anode 401 and the second cathode 404 , so that the respective luminescence colors can be independently emitted, thus allowing at least three color luminescences of green, red and orange (as mixture of green and red) to be issued from a substantially single pixel.
While the perspective layers and pixels may be designed in various manners, a specific example of the device of the above embodiment may be organized in the following dimensions:
(Respective Layer Thickness)
Anode ( 201 , 401 ): 1200 Å
Hole-transporting layer ( 202 , 402 ): 500 Å
Electron-transporting layer ( 203 , 403 ): 500 Å
Cathode ( 204 , 404 ): 2000 Å
Transparent insulating layer ( 300 ): 2000 Å
(Planar Sizes)
Pixel: 300 μm×300 μm
Aperture ( 205 , 405 ): 50 μm×300 μm
(Operation Voltage)
10 volts between each pair of an anode and a cathode.
FIG. 3 illustrated a laminar organization of an organic LED device according to a second embodiment of the present invention.
Referring to FIG. 3, the organic LED device includes a substrate 100 ;
a first anode 201 comprising a transparent electrode of ITO (indium tin oxide); a hole-transporting layer 202 comprising an aromatic diamine (of formula (1) above); an electron-transporting layer/luminescence layer 203 comprising tris(8-quinolinolato)aluminum complex (of formula (2) above); a first cathode 204 comprising a material having a low work function, such as Al or Mg—Ag alloy and provided with apertures 205 formed therein;
a transparent insulating layer 300 comprising, e.g., SiN or SiO 2 ;
a second anode 401 comprising a transparent electrode of ITO; a hole-transporting layer 402 comprising an aromatic diamine (of formula (1)); an electron-transporting layer/luminescence layer 403 comprising tris(8-quinolinolato)aluminum complex (of formula (2)) and a fluorescent substance (of formula (3) above); and a second cathode 404 comprising a material having a low work function such as Al or Mg—Ag alloy and provided with apertures 405 ;
a transparent insulating layer 500 comprising, e.g., SiN or SiO 2 ;
a third anode 601 comprising a transparent electrode of ITO; a hole-transporting layer 602 comprising an aromatic diamine (of formula (1)); an electron-transporting layer/luminescence layer 603 comprising tris(8-quinolinolato)aluminum complex (of formula (2)) and a distyryl derivative (of formula (4) below); and a third cathode 604 comprising a material having a low work function such as Al or Mg—Ag alloy and provided with apertures 605 .
FIG. 4 schematically illustrates a state of luminescence occurring in the organic LED device of FIG. 3 .
Referring to FIG. 4, each portion A represents luminescence caused by recombination of holes injected to the hole-transporting layer 202 from the first anode 201 and electrons injected to the electron-transporting layer 203 from the first anode 204 . In this instance, green luminescence inherent to tris(8-quinolinolato)aluminum complex of formula (2)) constituting the electron-transporting layer/luminescence layer 203 is emitted. The first cathode 204 is provided with the apertures 205 so that the luminescence is not caused at parts corresponding to the apertures 205 .
Referring further to FIG. 4, each portion B represents luminescence caused by recombination of holes injected to the hole-transporting layer 402 from the second anode 401 and electrons injected to the electron-transporting layer 403 from the second anode 404 . In this instance, rather than green luminescence inherent to tris(8-quinolinolato)aluminum complex constituting the electron-transporting layer/luminescence layer 403 , red luminescence attributable to the fluorescent substance (of formula (3)) added thereto as a dopant is predominant. The second cathode 404 is provided with the apertures 405 so that the luminescence is not caused at parts corresponding to the apertures 405 .
Further referring to FIG. 4, each portion C represents luminescence caused by recombination of holes injected to the hole-transporting layer 602 from the third anode 601 and electrons injected to the electron-transporting layer 603 from the third anode 604 . In this instance, blue luminescence attributable to the distyryl derivative (of formula (4)) added to tris(8-quinolinolato)aluminum complex as a dopant is predominant. The third cathode 604 is provided with the apertures 605 so that the luminescence is not caused at parts corresponding to the apertures 605 .
The red and blue luminescence fluxes occurring at the portion B and C are transmitted through the apertures 205 formed in the first cathode 204 and emitted together with the green luminescence flux occurring at the portions A through the substrate 100 .
Accordingly, in this embodiment, the different luminescence colors of R, G and B can be emitted from a horizontally single pixel. As a result, by sufficiently reducing the sizes of the apertures 205 , 405 and 605 , it is possible to provide an organic LED device from which different luminescence colors can be emitted with substantially no local deviation relative to a pixel size.
Regarding the respective luminescence colors, the green luminescence is caused by a voltage applied between the first anode 201 and the first cathode 204 , the red luminescence is caused by a voltage applied between the second anode 401 and the second cathode 404 , and the blue color is caused by a voltage applied between the third mode 601 and the third cathode 604 , so that the respective luminescence colors can be independently emitted.
FIG. 5 illustrates a laminar organization of an organic LED device according to a third embodiment of the present invention.
Referring to FIG. 5, the organic LED device includes a substrate 100 ;
a first anode 201 comprising a transparent electrode of ITO (indium tin oxide) provided with apertures 206 ; a hole-transporting layer 202 comprising an aromatic diamine (of formula (1) above); an electron-transporting layer/luminescence layer 203 comprising tris(8-quinolinolato)aluminum complex (of formula (2) above); a first cathode 204 comprising a material having a low work function, such as Al or Mg—Ag alloy and provided with apertures 205 formed therein;
a transparent insulating layer 300 comprising, e.g., SiN or SiO 2 ;
a second anode 401 comprising a transparent electrode of ITO; a hole-transporting layer 402 comprising an aromatic diamine (of formula (1)); an electron-transporting layer/luminescence layer 403 comprising tris(8-quinolinolato)aluminum complex (of formula (2)) and a fluorescent substance (of formula (3) above); and a second cathode 404 comprising a material having a low work function such as Al or Mg—Ag alloy and provided with apertures 405 ;
a transparent insulating layer 500 comprising, e.g., SiN or SiO 2 ;
a third anode 601 comprising a transparent electrode of ITO; a hole-transporting layer 602 comprising an aromatic diamine (of formula (1)); an electron-transporting layer/luminescence layer 603 comprising tris(8-quinolinolato)aluminum complex (of formula (2)) and a distyryl derivative (of formula (4) above); and a third cathode 604 comprising a material having a low work function such as Al or Mg—Ag alloy and provided with apertures 605 .
FIG. 6 schematically illustrates a state of luminescence occurring in the organic LED device of FIG. 5 .
Referring to FIG. 6, each portion A represents luminescence caused by recombination of holes injected to the hole-transporting layer 202 from the first anode 201 and electrons injected to the electron-transporting layer 203 from the first anode 204 . In this instance, green luminescence inherent to tris(8-quinolinolato)aluminum complex of formula (2) constituting the electron-transporting layer/luminescence layer 203 is emitted. The first anode 201 is provided with apertures 206 , the first cathode 204 is provided with apertures 205 , and the apertures 206 and 205 are formed at mutually slightly deviated positions, so that the luminescence occurs at positions corresponding to edges of the apertures 205 and 206 .
Referring further to FIG. 6, each portion B represents luminescence caused by recombination of holes injected to the hole-transporting layer 402 from the second anode 401 and electrons injected to the electron-transporting layer 403 from the second anode 404 . In this instance, rather than green luminescence inherent to tris(8-quinolinolato)aluminum complex constituting the electron-transporting layer/luminescence layer 403 , red luminescence attributable to the fluorescent substance (of formula (3)) added thereto as a dopant is predominant. The second anode 401 is provided with apertures 406 , the second cathode 404 is provided with apertures 405 , and the apertures 406 and 405 are formed at mutually slightly deviated positions, so that the luminescence occurs at positions corresponding to edges of the apertures 405 and 406 .
Further referring to FIG. 6, each portion C represents luminescence caused by recombination of holes injected to the hole-transporting layer 602 from the third anode 601 and electrons injected to the electron-transporting layer 603 from the third anode 604 . In this instance, blue luminescence attributable to the distyryl derivative (of formula (4)) added to tris(8-quinolinolato)aluminum complex as a dopant is predominant. The third anode 601 is provided with apertures 606 , the third cathode 604 is provided with apertures 605 , and the apertures 606 and 605 are formed at mutually slightly deviated positions, so that the luminescence occurs at positions corresponding to edges of the apertures 605 and 606 .
The portions A, B and C causing luminescence are disposed at edges of the apertures, so that the respectively generated luminescence fluxes at A, B and C are emitted through the apertures 205 of the first cathode 204 , the apertures 405 of the second 404 and the apertures 605 of the third cathode 604 to be emitted to a side opposite to the substrate 100 .
Accordingly, in this embodiment, the different luminescence colors of R, G and B can be emitted from a horizontally single pixel. As a result, by sufficiently reducing the sizes of the apertures 205 , 405 and 605 , it is possible to provide an organic LED device from which different luminescence colors can be emitted with substantially no local deviation relative to a pixel size.
Regarding the respective luminescence colors, the green luminescence is caused by a voltage applied between the first anode 201 and the first cathode 204 , the red luminescence is caused by a voltage applied between the second anode 401 and the second cathode 404 , and the blue color is caused by a voltage applied between the third mode 601 and the third cathode 604 , so that the respective luminescence colors can be independently emitted.
FIG. 7 illustrates a part of an image-reading apparatus 8 adopting the organic LED device shown in FIG. 3 according to the second embodiment of the present invention as a light source for illuminating an original.
Referring to FIG. 7, the image-reading apparatus 8 includes an organic LED device 1 as described above, a rod lens array 2 , a photoconverter element array 3 , a circuit substrate 4 , a housing 5 and a glass sheet 6 supporting an original 7 .
Light flux emitted from the organic LED device 1 supported in the housing 5 is transmitted through the glass sheet 6 to illuminate a surface of the original 7 supported thereon. Light flux reflected at the original 7 is passed through the rod lens array 2 to be focused at the photoconverter element array 3 mounted on the circuit substrate 4 . As a result, image data on the original 7 surface is read out by conversion into electric signals.
The image reading apparatus 8 thus comprising the organic LED device 1 , the rod lens array 2 , the photoelectric converter element array 3 , the circuit substrate 4 and the housing 5 is disposed to extend in a direction parallel to a side of the original supporting glass sheet 6 and is moved in an indicated arrow direction perpendicular to the extension direction thereof, so that images are read in a rectangular region determined by the length and the movement distance of the image reader 8 .
FIG. 8 shows a plan view of the organic LED device 1 in FIG. 7 as viewed from the side of the glass sheet 6 in FIG. 7 .
Referring to FIG. 8, the organic LED device ( 1 ) includes a transparent substrate 100 of, e.g., glass or plastic sheet, a light-emitting unit 101 as observed through the transparent substrate 100 and a flexible circuit sheet 102 . The anode, the cathode and the organic layer constituting the light-emitting unit 101 are disposed on a back of the substrate 100 .
FIG. 9 is an enlarged view of a section D shown in FIG. 8 showing the organization of the light-emitting unit 101 as observed through the transparent substrate 100 . More specifically, regarding the organization of the light-emitting unit ( 101 in FIG. 8) formed on the transparent substrate 100 , FIG. 9 shows a first anode 201 (of the organic LED device shown in FIG. 3) comprising a transparent electrode of ITO, a first cathode 204 comprising a conductor having a low work function such as Al or Mg—Ag alloy provided with apertures 205 , a second cathode 404 , and a third cathode 604 . The respective electrodes are connected to the flexible circuit sheet 102 .
Luminescence emitted from the third and second luminescence layers ( 603 and 403 in FIG. 3) are transmitted through the apertures 205 and emitted for illuminating the original surface together with the luminescence emitted from the first luminescence layer ( 203 in FIG. 3 ).
According to the above-mentioned image-reading apparatus, the positions of luminescence of different colors are substantially free from positional deviation, so that the directionality of illumination light reaching a certain point on the original is not different depending on different luminescence colors, so that the liability of color irregularity due to surface gloss of the original is deviated, thus allowing high-quality reading.
FIG. 10 is a side sectional view of a facsimile apparatus as a data processing apparatus including the image-reading apparatus of FIG. 7, which allows high-quality data processing through high-quality image reading owing to the use of an image-reading apparatus according to the present invention. Referring to FIG. 10, the facsimile apparatus incudes an image-reading apparatus 8 , a recording head 11 , a power supply unit 12 , a system control board 13 , a recording medium roll 14 from which a recording medium 14 a is supplied via a platen roller 14 b so as to allow recording by the recording head 11 , a feed roller 15 for feeding an original 7 via a separation claw 16 and a platen roller 17 , and an operation panel 18 .
The image reading apparatus according to the present invention is applicable not only to such a facsimile apparatus but also to various data processing apparatus, such as a scanner apparatus, utilizing a function of converting optical data into electric signals.
The organic LED device according to the present invention can also be used to constitute a (color) display apparatus allowing a high-quality display free from recognition of color points.
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A luminescence device is formed of a substrate, and a laminated layer structure formed on the substrate including a plurality of luminescence layers emitting different luminescence colors, and a plurality of electrodes forming pairs of electrodes each sandwiching an associated luminescence layer. At least one of the plurality of electrodes are provided with apertures, through which a luminescence flux emitted from at least one of the luminescence layers is transmitted. As a result, the luminescence device can emit different luminescence colors expected to cause color mixing with each other with a minimum of positional difference leading to color irregularity.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The field of this invention is displacement washing of porous media. More particularly, the invention involves washing and bleaching of pulp fiber mats.
2. Description of the Prior Art
In the manufacture of many materials, particularly chemicals, it often becomes necessary to separate the components of a mixture by dissolving one or more of them from the processing mixture. A common process requires washing the mixture with a solvent in which one or more of the materials constituting the mixture is soluble and the material sought to be recovered is insoluble.
In pulp and paper manufacture, it is often necessary to wash the pulp to remove contaminants or recover processing chemicals. For example, after wood chips are digested in a chemical solution designed to dissolve lignin, thereby freeing the wood pulp fibers, it is necessary to separate the lignin bearing spent cooking liquor from the pulp. Recovery of the liquor is important economically as a means of recovering cooking chemicals and environmentally as a means of preventing water pollution.
Black liquor recovery or brownstock washing, as it is usually called, is most often accomplished by rotary-drum vacuum filters. These filters are generally arranged in a series of four, with countercurrent flow of wash fluid. A typical rotary-drum vacuum washer comprises a wire-cloth cylinder partially submerged in a slurry tank of fibers. The cylinder is provided with a vacuum which, as the drum rotates, causes the pulp to build up on the wire. A number of showers are located near the drum surface to direct wash solution onto the pulp as it travels about the drum. The pulp at a selected consistency then discharges from the drum to the next washing stage for subsequent processing.
The cost of energy and stringent effluent controls emphasize the need to minimize dilution of recovered chemicals during brownstock washing while maintaining a high level of chemical recovery. In many cases poor washing efficiency may be limiting production and thus the incentive to improve efficiency is high.
In commercial brownstock displacement washers, the displacing wash solution is usually a more dilute solution of the spent cooking liquor that is sought to be displaced from the fiber pad. There is appreciable mixing within the pulp and fiber matrix between the liquor and wash fluid during washing, primarily as a result of preferential penetration of the wash fluid in regions of the pad having higher permeability. Fingers or channels of penetrating wash fluid form in these areas of pad nonuniformities. These "fingers" have lower pressure drops along their length due to the lower viscosity of the wash fluid with respect to the liquor to be displaced. The lower pressure drop promotes growth of the fingers. As a result of the development of the fingers or channels of wash fluid, large regions of stagnant liquor are eventually by-passed. This phenomemon, termed herein "viscous fingering," is the primary mechanism adversely influencing the effectiveness of brownstock displacement washing.
The viscous fingering phenomenon was first described in relation to secondary recovery of petroleum by water or brine injection into oil bearing strata. As has long been practiced in the oil industry, recovery is improved by displacing the oil from its porous formation with water. If the natural pressure of the formation were relied on alone, a significant amount of oil would otherwise remain locked in the ground. Researchers found that one of the problems encountered in water injection was a tendency for the water to preferentially pass through larger pore openings of the oil bearing rock, bypassing the smaller passageways. As a consequence, the water or brine would tend to "finger" through the strata and bypass oil. In a search for injectable liquids that could do a better job of displacing oil, prior workers tried to match the "mobility" of the displacing fluid to that of the oil. Mobility is defined as a characteristic of a fluid in certain media related to the piston like capability of the fluid to displace a solution retained in media without the displacing fluid channeling through the solution-media.
A low viscosity fluid such as water or brine injected into a porous strata typically was discovered to have a higher "mobility" than the more viscous oil. Early attempts to use such materials as glycerine, sugar or glycols failed on the basis of economics. Workers in the field of secondary oil recovery subsequently discovered that certain polymers dissolved in water at low concentrations impart a reduced mobility to injected water with respect to the oil sought to be displaced. These polymers exhibit a far greater impact on the mobility of water in rock formations than the measured solution viscosity in a laboratory would indicate. See Jennings, U.S. Pat. No. 3,687,199.
The unusual ability to improve oil recovery is a property of only a few select water-soluble polymers. Among these are the extensive family of acrylamide polymers and copolymers. The use of certain of these high weight polymers in injection waters, particularly synthetic, partially hydrolyzed polyacrylamide solutions, substantially improves secondary and tertiary oil recovery, as is described in the petroleum recovery literature. See Pye, "Improved Secondary Recovery by Control of Water Mobility," J. Pet. Tech. 911, (August 1964).
Very dilute solutions of these particular polymers, at 250-500 ppm exhibit viscosities differing only slightly from water. However, flow of these solutions through a microporous medium such as sandstone may exhibit 5-10 times more displacement capacity than other solutions having much higher viscosities. Such performance is exhibited only in porous media having a pore structure that forces displacing fluids to travel a tortuous path in passing through them.
In Pye, Id. at 911, Darcy's law, describing the flow of fluids through porous media, is expressed as ##EQU1## wherein q=flow rate (ft 3 /seconds); Δp=pressure drop (lbs/ft-sec. 2 ); A=area (ft 2 ); L=thickness of the medium (ft); μ=fluid viscosity (lb/sec-ft 2 ); and k=permeability of the media to the fluid (ft.).
Fluid viscosity and its interaction with the permeability of the medium are characteristics which function as resistance factors to flow. The ratio of permeability to viscosity (k/μ) for a particular system is often called the mobility, λ, of a fluid with respect to a particular medium.
The ratio of the mobility of a solvent to the mobility of a solution of the solvent containing a polymer, under equivalent conditions of fluid saturation and temperature has been termed by Pye the "resistance factor," R of the polymer solution. The resistance effect of a polymer where water is the solvent, is expressed in terms of mobilities, as: ##STR1##
As polymer is added, the mobility λ p =k p /μ p of the displacement solution, flowing through the particular porous medium, is reduced. Consequently, the resistance factor of a system, that is, the flowing properties of the solution without the polymer relative to the flowing properties of the solution with the polymer, is increased. The observed effect of the polymer addition is that the treated solution does a significantly improved job of displacing a viscous fluid retained in a porous medium than an untreated displacing solution. The ability of a displacing wash liquid to displace a viscous liquor from a porous medium increases as its mobility with respect to that porous medium is reduced.
SUMMARY OF THE INVENTION
In brief summary, the invention is an improved process for recovering processing chemicals from porous media, such as, for example, recovering spent black liquor from wood pulp by displacement washing. The process of the invention requires reducing the mobility of the wash solution so that it is less than the mobility of the solution sought to be recovered, wherein mobility is proportional to the permeability of the porous medium to the solution of interest and inversely proportional to the viscosity of that solution. A 0.05-2.0 ratio of wash solution mobility to the mobility of the solution to be recovered substantially improves chemical recovery for a given quantity of wash water. The preferred range of the mobility ratio is 0.2-1.0.
Any substance or change of physical conditions that establishes a mobility ratio within the 0.05-2.0 range and that is compatible with the system and substances of interest is within the scope of the invention. A change in processing conditions, such as, for example, a reduction in temperature decreasing the viscosity of the displacing fluid is sometimes sufficient to attain the proper mobility ratio. The principal method of the invention requires the addition of a chemical substance to increase the viscosity or to, in effect, reduce the permeability of the porous media with respect to the washing fluid.
A number of starches and modified ethylene glycols are suitable for mobility reduction, primarily through viscosity increases. The identification of these viscosity modifiers is within the capability of one skilled in the chemical arts.
A preferred process requires the addition of polymers that principally affect the permeability of the wash solution with respect to the media within which the liquid to be displaced is held. Examples of polymers in this group include copolymers of acrylamide and acrylic acid, carboxypolymethylene, poly acrylic acid and deacetylated chitin. A preferred polymer is the copolymer of acrylamide and acrylic acid having a molecular weight greater than 10 6 .
The preferred polymer addition may be in the range of 2-200 ppm with the minimum amount necessary being used to accomplish the required range of mobility ratios. For the preferred copolymer of acrylamide and acrylic acid, a 6-10 ppm addition to the wash solution of a brownstock washer doubles the efficiency of the washer in displacing 2.39 cp kraft black liquor from wood pulp.
The effect of the mobility modification is to reduce the amount of wash solution required to displace a chemical laden solution to a selected yield. Alternatively, substance yield of the dissolved solids may be increased without increasing dilution of the solution ultimately recovered.
The carry-over of chemicals from the washing operation into bleaching stages can be decreased substantially, for example from 2.2% to 1.1%. In terms of economics, for the typical 1000 tons per day pulp mill, savings in chemical consumption may amount to more than $1 million per year. The additional increment of recovery may be extremely important in pollution control schemes where the last fractional percentage recovery of pollutants tends to be exceedingly expensive.
It is an object of the present invention to provide, in displacement washing of pulp, a process for improving chemical recovery at the brownstock washers. The effect is to minimize chemical consumptions for bleaching downstream and effluent BOD, color and toxicity.
The benefits of the process of the invention may be realized as a reduction in wash water requirements. Less steam is needed to evaporate waste liquor resulting in savings of approximately $3,000 per day at current energy costs for a 500 ton per day pulp mill. Polymer costs would be on the order of $85/day. These benefits are possible with no modification of existing washing equipment or substantial capital cost.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are schematic representations of the effect of polymer addition on channeling or viscous fingering in comparison with the prior art.
FIG. 3 shows the effect on substance yield of adding polymer to wash solutions to reduce mobility ratio, as a function of dilution factor.
FIG. 4 is a graph showing the effect of polymer addition to wash solution on displacement ratio, as a function of dilution factor.
FIG. 5 is a graph of the effect of polymer addition to wash solution on displacement washing efficiency as a function of dilution factor.
DETAILED DESCRIPTION OF THE INVENTION
It has been discovered that the principles employed in secondary oil recovery may be utilized in improving displacement washing recoveries from the much thinner strata or porous media found in the chemical process industry. The new process is particularly advantageous for recovering spent cooking liquor and bleaching chemicals from pulp and paper processes.
The addition of minute quantities of certain high molecular weight polymers to a wash solution or liquor can appreciably decrease the mobility of that liquor with respect to the more concentrated liquor to be recovered. Channeling or viscous fingering in a fiber pad is retarded if the mobility of the wash liquor can be decreased below that of the fluid to be displaced. When wash fluid begins to penetrate a region of high permeability in the pad, the region becomes filled with the wash liquid which has a lower mobility than the solution to be displaced and the channeling penetration is retarded.
The viscous fingering which occurs during the displacement of concentrated spent cooking liquor with a less concentrated wash liquor is illustrated in FIG. 1. FIGS. 1 and 2 present a series of drawings illustrating the longitudinal dispersion of two fluids in a porous medium at different stages of washing with and without polymer added to the wash fluid. Viscous fingering is shown to be less in the case where polymer has been added to the wash fluid.
Referring to FIGS. 1 and 2, illustrations 1 and 4 compare displacement washing results in a pulp pad at a dilution factor (defined below) of -4, where the weight of wash liquor added is only 55% of the weight of the original liquor in a fiber pad at 10% consistency. Despite the much greater longitudinal mixing in the case without polymer, none of the fingers of wash liquor have penetrated the entire pad depth and the displaced liquor has the same concentration as the original liquor. In terms of externally measured variables, both systems exhibit perfect displacement.
As dilution factor increases above -4.0, illustrations 2 and 5, fingers of wash liquor with no polymer added penetrate the full depth of the pad with increasing frequency and more and more wash liquor dilutes the displaced fluid. Viscous fingering is now manifested in terms of lower displacement ratios than those predicted for ideal displacement. At dilution factors less than -4.0, none of the wash fluid with polymer added, illustration 5, has penetrated the pad and in terms of externally measured variables displacement still appears perfect.
At a dilution factor of +4.0, illustration 3 and 6, the wash liquor with polymer added completely displaces the original liquor, whereas, when no polymer is used, pockets of the original liquor are bypassed and remain unrecovered.
EXAMPLE 1
Pads of unbeaten, unbleached kraft pulp fibers were formed on a Buchner funnel by filtration from a suspension in spent sulfate cooking liquor. The resultant pads had basis weights of approximately 1,000 g/m 2 and fiber concentrations of around 3.75%.
To recover the liquor entrained in the pad, water or dilute polymer solutions of known concentration and viscosity were carefully poured through a course wire screen onto the top of the fiber pads. The entrained liquors were displaced under gravity and the underflows sampled continuously. Washing was discontinued when practically all of the entrained liquors had been displaced. For each sample, the solids content and the cumulative volume displaced were measured. These results were expressed in terms of cumulative substance yield and dilution factor. Cumulative substance yield is defined as the percent of recovery of the total amount solids retained in the pad. Dilution factor is defined as the weight of wash fluid added to the pad in excess of the liquor originally retained in the pad after dewatering, per unit weight of fiber. According to this definition, dilution factor is negative if the weight of wash fluid is less than the weight of liquor originally in the pad.
In a series of experiments, black liquor was displaced from the fiber pads using distilled water and dilute solutions of carboxypolymethylene.
The experiments were performed at either 20° C. or 60° C. In some cases, air was drawn through the pad prior to displacement.
Under all experimental conditions tried, the addition of small quantities of soluble polymer to the wash fluid markedly increased the displacement efficiency. Typical results are presented in FIG. 3 as a graph of substance yield vs. dilution factor. It can be seen that under the conditions of these experiments, decreasing the mobility ratio, that is, the ratio of wash solution mobility to that of the solution to be recovered, from 2.39 to 0.12 increased substance yield at zero dilution factor from 78% to 98%.
EXAMPLE 2
Trace amounts of a high molecular weight non-ionic polyacrylamide (DOW XD 30150-00), manufactured by Dow Chemical Company of Midland, Mich., were added to wash fluid in a laboratory simulation of a commercial brownstock washer. The spent cooking liquor in these tests was red liquor from a sulfite cook.
All phases of washing which occur during each revolution of a typical brownstock washer were simulated under controlled laboratory conditions. The apparatus used was a filter comprising a cylinder 10.6 cm in diameter and approximately 5 cm in length. One end of the cylinder was covered with a wire screen. The opposite end was closed and connected via a liquid trap to a source of vacuum. A circular rim 2 cm high extended about the periphery of the open surface of the wire screen. The vacuum in the laboratory filter was adjusted to duplicate that of a mill drum washer. The filter was immersed in an agitated suspension of softwood sulphite fibers and spent sulfite cooking liquor (red liquor) for the same length of time as the period of immersion on the drum washer. Both the wood pulp fibers and liquor were obtained from the number one brownstock washer at Weyerhaeuser Company's Cosmopolis mill.
After pad formation, the filter was removed from the suspension and the resultant pad was allowed to drain under vacuum prior to washing. A quantity of dilute spent cooking liquor, corresponding to the volume per unit area sprayed onto the industrial washer, was poured onto the surface of the fiber pad and drawn through under vacuum.
A large volume of pure water was then drawn through the pad to recover the residual red liquor solids not displaced during the washing phase.
Measurements were made of the volume and solids content of the wash liquor, the liquor displaced during washing and the liquor displaced during the final rinse.
The experimental conditions were chosen to match those on the actual washer which are typically as follows:
(i) drum emersion=60%; (ii) drum speed=2.4 rpm; (iii) total solids at inlet=12%; (iv) total solids in wash fluid=6%; (v) vacuum=250 mm Hg; (vi) temperature in vat=66° C.; and (vii) dilution factor of -4 to +5.
The simulation was repeated using varying quantities of wash liquor with and without the addition of 6-10 ppm of polyacrylamide.
Referring to FIG. 4, a graph of displacement ratio, defined as the ratio of the weight of recovered solids to the weight of solids which could be recovered with perfect displacement, versus dilution factor, defined as the weight of wash fluid in excess of the weight of original liquor in the pad per unit weight of fiber, is shown.
It can be seen from FIG. 4 that the addition of a minute quantity of a high molecular weight polymer to the wash fluid can markedly increase the displacement efficiency over the complete range of dilution factors of practical interest. At zero dilution factor, the displacement ratio can be increased from 85% at point 11 to 92% at point 12 through the addition of polymer. That is, the residual, washable solids retained in the pad were approximately halved.
A line 13 representing perfect displacement has been included in FIG. 4 for reference. The position of this line was calculated assuming no longitudinal mixing between the original liquor and wash fluid.
The percentage reduction in undisplaced solids through the addition of polymer increased from zero at a dilution factor of -4 to 100% at a dilution factor in excess of +4 when displacement for the polymer system was complete. This behavior can be rationalized in terms of the concept of viscous fingering, as described above with reference to FIGS. 1 and 2.
EXAMPLE 3
Mill Trial
To further test the displacement washing advantages shown in the laboratory under actual mill conditions, a small quantity of a 0.17% solution of polyacrylamide, DOW XD-30150-00, manufactured by Dow Chemical Company of Midland, Mich., was metered into the main stream of wash fluid supplied to the number one brownstock washer at Cosmopolis such that the concentration of polymer in the main fluid was less than 10 ppm.
During the one-hour trial period, the operating conditions on the number one brownstock washer were maintained constant at:
(i) drum emersion=60%; (ii) drum speed=2.0 rpm; (iii) total solids in vat=14.64%; (iv) total solids in wash fluid=8.93%; (v) vacuum=250 mm Hg; (vi) temperature in vat=66° C.; (vii) temperature of wash fluid=56° C.; (viii) flow rate of wash fluids=2350 gpm (620 gpm); (ix) consistency of washed pad=8.88%; (x) throughput of fiber=20 T/hr.; and (xi) consistency in vat=1.0%. Under these conditions, the washer operated with a dilution factor of -2.4.
The concentrated polymer solution was injected into the pipe supplying wash fluid to the washer approximately one meter upstream from the header which distributes fluid to the shower nozzles. Turbulence within the pipe was assumed to be sufficient to evenly distribute the polymer throughout the main flow of wash fluid. The maximum rate of injection of polymer solution was only approximately 0.02% of the flow rate of wash fluid and its effect on dilution factor can be neglected.
Experiments were performed on the number one brownstock washer in order to measure the displacement efficiency with and without the addition of 6.05 and 9.33 ppm of polymers to the wash fluid. In each case polymer was added to the wash fluid for a period of approximately ten minutes. Multiple samples of the washed pulp were taken during this period of addition and, for purposes of comparison, during the ten-minute periods directly before and after the period of addition. Care was taken to always sample the washed pulp from the same point on the drum surface in order the minimize erroneous measurements resulting from any inconsistent variations in washing or drainage efficiency over the drum surface.
The concentrations of dissolved solids in the vat and in the wash liquor were 14.64 g solids/100 g liquor and 8.93 g solids/100 g liquor, respectively. Since the concentration of dissolved solids in the vat equals the concentration of dissolved solids in the pad prior to displacement, the maximum possible recovery of displaced solids corresponds to complete replacement of the original liquor in the pad with wash liquor. Consequently, in this case, the maximum possible recovery was 5.71 g solids/100 g liquor.
The concentrations of dissolved solids in the entrained liquors were measured. A tabulation of these results appears in Table A. The actual recovery of dissolved solids increased from 4.24 g solids/100 g liquor to 4.54 g solids/100 g liquor due to the addition of polymer. The recoveries due to the different levels of polymer concentrations were not statistically significant. The increases in recovery due to the addition of polymer are statistically significant to the 95% confidence level.
TABLE A______________________________________Displacement Data for Number One Washer Final Reduction in Concentration Concentration of Dissolved of Dissolved Solids in Solids inPolymer Concentration (ppm) Consistency of Pad % ##STR2## ##STR3##______________________________________0.00 8.729 11.12 3.52 8.562 10.62 4.02 8.849 10.50 4.14 8.814 10.42 4.22 9.429 10.32 4.32 8.555 10.24 4.40 9.631 10.24 4.40 8.775 10.14 4.50 8.912 9.95 4.69 Avg. 8.92 Avg. 10.39 4.246.05 8.913 10.23 4.41 8.571 10.05 4.59 8.920 9.94 4.70 8.72 10.07 4.579.33 8.425 10.24 4.40 9.179 10.17 4.47 9.353 10.13 4.51 8.916 9.96 4.68 8.97 10.13 4.51______________________________________
The ratio of the actual recovery to the maximum possible recovery is termed displacement ratio. In this case the percentage displacement ratio increased from 74.2% to 79.5% due to the addition of polymer. In other words, the residual washable solids were reduced by 20%. These results have been combined with the appropriate dilution factor and superimposed on the results from the laboratory simulation of this washer presented in FIG. 4.
The mill data is in good agreement with predictions based on laboratory data. As expected, at a dilution factor of -2.4, displacement on the drum washer appeared to be perfect after the polymer had been added. It is impossible to achieve a displacement ratio greater than 78% at this dilution factor, since the weight of wash liquor added is only 78% of the weight of the original liquor.
The consistencies of the samples of fiber pads leaving the washer were measured. These results are also shown in Table A. There is no statistically significant difference between the consistencies of pad samples taken before and after the addition of polymer. It is concluded that, in this case, the polymer did not affect drainage through the pad on the washer.
Washer Efficiencies
In a drum washer, both displacement and "dilution and thickening" are used to separate pulp and spent cooking chemicals. Consequently, to predict the overall efficiency of a drum washer, it is necessary to consider both of the washing mechanisms and their interaction. However, once the displacement process is characterized, all of the pulp and liquor flows around a drum washer can be deduced from simple mass balances. The steady-state compositions and volumes of all flows around the washer can be deduced for a particular dilution factor using the empirical description of the displacement process together with a comprehensive series of simultaneous equations which describe the mass balances for each of the elemental processes of mixing, dilution and thickening.
For example, the data presented in FIG. 4 can be used to deduce the steady-state composition of all the streams around the number one washer. It should be noted that this level of analysis does not consider the interaction between washers. It does, however, enable the overall operation of a washer to be characterized.
A Nordeen Efficiency Factor, E, may be used to characterize washing efficiency. E is defined as the number of countercurrent ideal mixing stages in series that is required to achieve the same performance as the washer or plant being considered. Kommonen, "Pulp Washing Evaluation for Design and Operation," Papper Och Tra, 6:347 (1978). E can be calculated knowing inlet and outlet conditions using equation (1). ##EQU2## where L=liquor flow; C=concentration of dissolved solids; subscript "p" refers to pulp flow; subscript "l" refers to liquor flow; subscript "i" refers to inlet; and subscript "o" refers to outlet.
When L li =L po and L lo =L pi , equation (1) becomes indeterminant, and equation (2) applies: ##EQU3##
Values of E which characterize the operation of the number one washer at Cosmopolis have been calculated for a wide range of dilution factors using equations (1) and (2) and are presented in FIG. 5.
FIG. 5 is a graph of the efficiency factor E versus dilution factor for the washer operating with and without polymer. Over a normal range of dilution factors (0 to 4), the value of E is not strongly dependent upon dilution factor. The Nordeen efficiency factor is approximately 6.4 without polymer and increases to approximately 11.5 after the addition of polymer. That is, a single washer with polymer can operate with almost the same effectiveness as two washers in series without polymer.
Systems Analysis
In order to evaluate the effect of polymer addition at the first washer on the efficiency of the whole wash room, it is necessary to characterize the efficiency of the other washers. The operating conditions of the other washers at Cosmopolis were measured during the mill trial of Example 3 and these data enabled the washing efficiencies of the other washers to be calculated. The results are presented in Table B together with the corresponding values for E.
TABLE B__________________________________________________________________________Operating Data for Cosmopolis Washer Two, Three and Decker Through- Vat Drum Inlet Wash OutletWasherSpeed, put, Vacuum, Cons, Cons, Solids, Solids, Solids, Temp., NordeenIdentityRPM TPH mm Hg % % % % % °C. Factor__________________________________________________________________________Two 2.2 20 265 0.8 10.9 10.5 6.2 8.3 55 2.04Three2.3 20 230 1.0 12.5 6.8 3.4 4.5 48 3.55Decker2.7 20 -- 1.4 14.0 3.7 0.0 1.3 48 2.82__________________________________________________________________________
The overall Nordeen efficiency factor for the four washers in series is simply the sum of the individual Nordeen efficiency factors. The overall Nordeen efficiency factor for the four washers without polymer is 6.4+2.0+3.6+2.8=14.8. The overall steady-state efficiency is expected to be increased to 11.5+2.0+3.6+2.8=19.9 if polymer were to be added to the first washer. This represents a 34% increase in the overall wash room efficiency. A 25% increase in overall efficiency would be equivalent to adding another washer in series to the existing washers.
The increased washing efficiency could be used either to increase the overall chemical recovery and reduce the carryover of dissolved solids at the same dilution factor, or to decrease the load on the evaporator and energy consumption by reducing dilution factor while maintaining the same solids recovery.
Decreased Dilution Factor
This analysis assumes that the consistencies of the pulp streams entering and leaving the wash room are equal. Under these conditions, L pi =L po and L li =L lo and a simple relationship between displacement ration, Y, Nordeen Efficiency Factor and wash liquor ratio, W, can be deduced from the definition of displacement ratio and equation (1): ##EQU4## When the dilution factor equals zero, equation (3) becomes indeterminant and equation (4), which can be deduced from equation (2) applies: ##EQU5##
Substituting the normal dilution factor at Cosmopolis of 1.37 and the value of 14.8 for the Nordeen Efficiency Factor corresponding to normal operation without polymers, into equation (3) gives a value for the overall displacement ratio for all the washers of 97.9%. In other words, 6.3% of the washable solids is being carried over in the pulp stream. Substituting the value of 19.3 for the Nordeen Efficiency Factor corresponding to operation with polymer, and the value for the overall displacement ratio of 97.9% into equation (3) gives a dilution factor of 0.74. This is the dilution factor required with polymer to achieve the same displacement ratio.
The addition of polymer is expected to reduce the overall dilution factor by 0.63 ton of water per ton of pulp. This represents an appreciable reduction in demand for both evaporator capacity and energy.
Increased Chemical Recovery
Substituting the value for the overall Nordeen Efficiency Factor corresponding to polymer addition at the first washer, 19.9, and a dilution factor value of 1.37 into equation (4) gives an overall displacement ratio for washable solids of 99.0%. That is, if the dilution factor is not changed, the carryover of washable solids is expected to be reduced from 2.1% to 1.0% through the use of polymer. A 50% reduction in carry-over represents an appreciable reduction in the demand for bleaching chemicals, and in the color and BOD of mill effluent.
Cost of Polymer
The DOW XD-30150-00 polymer used in this trial currently sells in bulk for $3.50 per kilogram or $1.60 per pound (1979 dollars). The number one brownstock washer at Cosmopolis operating at a dilution factor of zero would consume one kilogram of polymer per hour if polymer were to be added at a concentration of 6 ppm in the wash fluid. Consequently, the cost of adding polymer to the number one washer would be $3.50 per hour or 17.5 cents per oven-dried ton of pulp.
A number of polymers, primarily affecting permeability behavior, will accomplish the mobility reducing effect on displacement solutions. An ultra high molecular weight polymer, having a MW of at least about 1,000,000 is especially useful. Stability of the compound is usually not a critical criteria since the chemical may be injected into the wash water stream just prior to flow into the washers. Subsequent destruction due to shear stresses in pumping is of little consequence at the low addition rates involved. It is postulated that a characteristic of the polymer sought is the ability of the polymer to hydrate or "uncoil" in a particular media-liquor environment. This uncoiling is thought to produce the resistance to flow through the tortuous pathways in the porous media.
The following is a list of polymers, which either alone or in combination have the desired effect of improving washer efficiency: polyethylene oxide; polyacryl amide; polyvinyl pyprolidone; polyacrylic acid; polymethacrylic acid; carboxymethyl cellulose-Na, K, Li, amine salts; alginic acid, K, Na, Li, amine salts; polymaleic acid; and copolymers of two or more of the following monomers: methacrylic acid, acrylic acid, acryl acid, acrylamide, vinyl pyprolidone, maleic anhydride, styrene sulphonate (Na, K, Li, salts), vinyl ether, methacryl amide, vinyl acetate (alcohol), ethylene oxide; polyvinyl alcohol; methyl cellulose; hydroethyl/propyl cellulose; starch; starch/PAN; poly styrene sulphonate, (Na, K, Li, ammonia salts), polyvinyl sulphonate (k, Na, Li, ammonia salt), carageenan, cellulose sulphate (Na, K, Li, ammonia, amine salt), polyvinyl pyridine and quarternized pyridinius salts, deacetylated karaya gum, chitosan, guar gum and locust bean gum.
The process is effective in either acid or alkali systems. A non-ionic polymer is appropriate for acid systems while an ionic polymer is used in alkali systems. The washing improvements are not equipment limited. The process is useful with ring diffusers, kamyr diffusers, blow pits and the like. The process is also useful in bleaching operations where uniformity of the results is improved. Other uses, such as separations of aqueous and non-aqueous liquids; for example, the separation of oils from vegetable matter is within the scope of the invention as will be apparent to those skilled in the art.
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An improved displacement washing process for recovering processing chemicals from a porous medium, particularly wood pulp, is described. The effective mobility of a displacing solution, typically a more dilute solution of the chemical sought to be recovered, is reduced such that it is less than the mobility of the solution to be recovered. In a pulp mill washing system, consumption of wash water may be reduced 0.6 tons of water per ton of pulp produced without reducing chemical recovery. Conversely, chemical effluent from the washer could be reduced by 50% without increasing wash water requirement. Mobility is proportional to the permeability of the porous medium with respect to the solution of interest and inversely proportional to the viscosity of that solution. Mobility of the wash solution relative to the solution to be displaced is preferrably reduced by the addition of a soluble, high molecular weight polymer, greater than 10 6 , until the ratio of the mobility of the wash solution to that of the chemical rich solution is in the range of 0.05-2.0, preferably within the range of 0.2-1. As examples, copolymers of acrylamide and acrylic acid, carboxypolymethylene, polyacrylic acid and deacetylated chitin have been found to be effective in reducing mobility. The presence of 6-10 ppm of a copolymer of acrylamide and acrylic acid of MW greater than 10 6 in the wash solution of a brownstock washer can double the efficiency of the washer.
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FIELD OF THE INVENTION
[0001] The present invention relates to a technique for scanning a document image, and outputting it as a digital image signal.
BACKGROUND OF THE INVENTION
[0002] Normally, an image scanning device represented by a color image scanner and the like has light sources (e.g., LEDs) with emission wavelength characteristics of red (R), green (G), and blue (B), and scans information from a document using a common monochrome line image sensor while switching the ON/OFF states of them, and obtains two-dimensional image information while moving the monochrome line image sensor or document in a direction perpendicular to the arrangement direction of detection elements of the monochrome line image sensor (normally called a sub-scan direction) (e.g., Japanese Patent Laid-Open No. 2003-315931).
[0003] The luminous spectrum characteristics of the LEDs of respective colors as R, G, and B light sources used in the image scanning device are approximately as shown in FIG. 3 .
[0004] On the other hand, the luminousity characteristics of human eyes have spectral sensitivity characteristics different from the emission wavelength characteristics of the LEDs, as shown in the CIE-RGB calorimetric system color matching functions shown in FIG. 4 .
[0005] In order to compensate for these differences, the scanned image data undergoes color correction processes to improve color reproducibility of the scanned image. However, high color reproducibility has not been obtained yet.
[0006] Especially, an image scanning device using only R, G, and B light-emitting members cannot express a negative stimulus value of a red component which appears near a wavelength of 500 nm in the CIE-RGB colorimetric system color matching functions. Hence, the color reproducibility of an emerald system is prone to be poor.
[0007] In order to express a color that cannot be expressed by the scanning means using only R, G, and B primary colors, a method of extracting a color different from R, G, and B is known (Japanese Patent Laid-Open No. 2003-284084). This method is applied to a two-dimensional image sensor adopted in a digital camera, and detects one pixel by a plurality of types of extraction units which are limited to the wavelength ranges of R, G, and B and emerald color in place of switching light source colors so as to obtain color information from an object.
[0008] However, according to the technique of this reference, since data for one pixel is extracted by extraction units of independent colors, the light-receiving area of each extraction unit becomes too small to obtain a sufficient light-receiving amount. This imposes an influence on the S/N ratio. In addition, higher cost is required to manufacture such image sensing element, and it is difficult to apply this method to the image scanning device.
SUMMARY OF THE INVENTION
[0009] The present invention has been made in consideration of the above problems, and has as its object to provide a technique which can achieve more faithful color reproduction by a relative simple arrangement.
[0010] In order to solve the above problems, an image scanning device of the present invention comprises the following arrangement.
[0011] That is, there is provided an image scanning device comprising:
an illumination unit for illuminating a document while selectively turning on visible light beams of at least four colors in turn; an image scanning unit for scanning the document image illuminated by the illumination unit and outputting image data of respective colors; a moving unit for relatively moving the document image and the image scanning unit; and a control unit for, when the image scanning unit executes scan processes of the document image for respective colors while performing relative movement by the moving unit, controlling not to successively execute the scan process of a first color having highest spectral luminous efficacy among the visible light beams of at least four colors and the scan process of a second color having second highest spectral luminous efficacy.
[0016] Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
[0018] FIG. 1 is a schematic sectional view of an image scanning device according to an embodiment of the present invention;
[0019] FIG. 2 is a flowchart showing the processing sequence of the image scanning device according to the embodiment of the present invention;
[0020] FIG. 3 shows the luminous spectrum characteristics of R, G, and B LEDs;
[0021] FIG. 4 shows the CIE-RGB colorimetric system color matching functions;
[0022] FIG. 5 is a block diagram showing principal part of an image processing circuit shown in FIG. 2 ;
[0023] FIG. 6 shows the luminous spectrum characteristics after correction of the first embodiment;
[0024] FIG. 7 is a block diagram of an image scanning device of the first embodiment;
[0025] FIG. 8 is a timing chart upon scanning of the image scanning device of the first embodiment;
[0026] FIGS. 9A and 9B are flowcharts showing the setting processing sequence of ON time data and shading correction data of the first embodiment;
[0027] FIG. 10 shows the luminous spectrum characteristics after correction of the second embodiment;
[0028] FIG. 11 is a schematic sectional view of a device which scans a transmitting document and is to be applied to the second embodiment;
[0029] FIG. 12 shows the luminous spectrum characteristics of R, G, B, and E LEDs in the second embodiment;
[0030] FIG. 13 is a functional block diagram of a scanner driver which runs on a host computer in a modification of the second embodiment;
[0031] FIG. 14 shows color difference characteristics of 3- and 4-color scan modes;
[0032] FIG. 15 is a flowchart showing the processing contents of the scanner driver in the modification of the second embodiment; and
[0033] FIGS. 16A and 16B respectively show a case wherein E and G components are successively scanned, and a case wherein E and G components are scanned every other colors.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] Preferred embodiments of the present invention will be described in detail hereinafter with reference to the accompanying drawings. Note that LEDs as R, G, and B light sources in embodiments respectively have dominant emission wavelengths of 630 nm (R LED), 525 nm (G LED), and 470 nm (B LED). These characteristics are not special but general LED characteristics.
[0035] In the arrangement using such R, G, and B LEDs, some colors are difficult to express. Especially, the CIE-RGB colorimetric system color matching functions include a negative stimulus value of a red component which appears near a wavelength of 500 nm, as shown in FIG. 4 , and it is difficult to express this color by three colors, i.e., R, G, and B. Hence, this embodiment will exemplify a case wherein an emerald LED which has a dominant emission wavelength near 500 nm is arranged. The luminous spectrum characteristics of the four-color LEDs (R, G, B, and E) in this embodiment are as shown in FIG. 12 .
First Embodiment
[0036] FIG. 1 is a schematic sectional view of a document scanning device (image scanner) of this embodiment.
[0037] Referring to FIG. 1 , reference numeral 101 denotes a contact image sensor unit (to be abbreviated as CIS hereinafter). Reference numeral 104 denotes an optical waveguide light source in which a red LED (R-LED), green LED (G-LED), blue LED (B-LED), and an emerald LED (emerald color will be referred to as E color hereinafter, and the emerald LED will be referred to as E-LED hereinafter) are arranged at the end portion of the waveguide which is elongated in a direction perpendicular to the plane of page (main scan direction), and which guides light emitted by each LED in the main scan direction by internal reflection to linearly irradiate a document 106 to be scanned on a document table glass (platen glass) 105 with that light.
[0038] Light reflected by the document surface is received by a monochrome image sensor 102 via a lens array 103 . Light-receiving elements of the monochrome image sensor line up in the main scan direction. In the optical waveguide light source 104 , the R-LED is driven to emit light, and that light is received by the monochrome image sensor 102 , thus scanning R component data for one line. Then, the G, B, and E LEDs are time-divisionally driven to emit light, thus scanning G, B, and E data for one line. The same process is repeated by moving the CIS 101 along a guide (not shown) in the sub-scan direction at a constant speed by the reciprocal number of the scan resolution in the sub-scan direction in synchronism with the time (line scan time) required to scan four colors, thereby obtaining two-dimensional image data.
[0039] Reference numeral 107 denotes an electronic circuit board which is arranged in the image scanning device, and mounts circuits to be described later. The circuit board 107 is electrically connected to the CIS 101 via a flexible cable 108 .
[0040] FIG. 7 is a block diagram when viewed from the electrical system of the image scanning device of this embodiment. The same reference numerals in FIG. 7 denote the same parts as in FIG. 1 .
[0041] Referring to FIG. 7 , reference numeral 200 denotes a controller for controlling the overall device. The controller 200 also makes control that pertains to communications with an external host computer 300 .
[0042] An analog electrical signal photoelectrically converted by the CIS 101 is converted into a digital electrical signal by an AFE circuit 201 including a sample/hold circuit such as CDS (correlative double sampling circuit) and the like after it undergoes gain adjustment and DC offset adjustment. A shading correction circuit 202 corrects the light distribution characteristics of an optical system. That is, the shading correction circuit 202 stores, as shading correction data, reference level data which is generated by scanning light reflected by a white reference plate (not shown) arranged outside the scan document range by the CIS 101 , and performs shading correction of image data generated by scanning the document to be scanned on the basis of this correction data. Note that the shading correction data may be output to and saved by the host computer 300 as an external apparatus, and data required for scan may be downloaded from the host computer 300 to the image scanning device upon executing processes.
[0043] An image processing circuit 203 performs predetermined processes of image data such as a gamma conversion process, a packing process according to an image scan mode (binary, 24-bit multi-valued, and the like) which is set in advance by the host computer 300 , and the like. When “binary” is set as the scan mode, a document image is scanned by driving only the G-LED, and the image processing circuit 203 binarizes and outputs the scanned data. When “32-bit multi-valued” is designated, four R, G, B, and E LEDs are sequentially driven to perform image processes (to be described later) for respective lines, i.e., in the order of 1-line data of an R component, 1-line data of a G component, 1-line data of a B component, and 1-line data of an E component to have a pixel of each of R, G, B, and E components as 8-bit data, and the processed data is output to the host computer 300 .
[0044] An interface circuit 250 exchanges control signals and outputs an image signal with the host computer 300 such as a personal computer or the like. In this embodiment, the interface circuit 250 comprises a USB interface circuit. However, a SCSI interface circuit may be used. That is, the present invention is not limited in terms of the types of interfaces.
[0045] An LED driver 204 outputs drive signals of the four, i.e., R, G, B, and E LEDs included in the optical waveguide 104 in the CIS 101 under the control of the controller 200 . A motor driver 205 generates a drive signal to a motor 206 which moves the CIS in the sub-scan direction.
[0046] Reference numeral 207 also denotes an LED driver which is used to turn on a transmitting document illumination unit 210 (including a light source) which is connected via an interface 208 to scan a transmitting document such as a positive/negative film or the like.
[0047] The process of the image scanning device of this embodiment will be described below with reference to the flowchart of FIG. 2 . Note that a program associated with FIG. 2 is stored in a ROM (not shown) in the controller 200 .
[0048] Upon completion of initialization after power ON, the control waits for the scan mode designated by the host computer 300 as an external apparatus (strictly speaking, a scanner driver which is running on the host computer 300 ). The scan mode includes a binary mode (scan mode by only the G-LED), a 24-bit multi-valued mode (scan mode using three, i.e., R, G, and B LEDs), and a 32-bit multi-valued mode (scan mode using four, i.e., R, G, B, and E LEDs). Upon reception of a designation command of one of these modes, setups are made accordingly (step S 801 ).
[0049] In step S 802 , the control waits for reception of a pre-scan start instruction. Upon reception of a pre-scan start instruction request from the host computer 300 , the control inquires the host computer 300 as to whether or not it holds LED ON time data and shading correction data, and checks based on its response if the host computer 300 stores these pieces of information. As a result, if the host computer 300 stores the LED ON time data and shading correction data, the control requires the host computer 300 of the LED ON time data and shading correction data, and downloads them to this image scanning device to make various setups in step S 804 .
[0050] On the other hand, if it is determined in step S 803 that the host computer 300 does not store any LED ON time data and shading correction data, the flow advances to step S 805 to generate LED ON time data and shading correction data. FIG. 8 is a timing chart of the generation process of the LED ON time data and shading correction data in step S 805 , and FIGS. 9A and 9B shows the processing sequence of that process. The generation process will be described below with reference to these figures. Note that a case will be explained below wherein “32-bit multi-valued” is designated as the scan mode.
[0051] In step S 1001 , the output signal from the monochrome image sensor 102 is read as black shading correction data while all the LEDs are OFF, and is set in the external apparatus (host computer) 300 . With this setup, offsets, variations, and the like for respective pixels due to the monochrome image sensor 102 can be corrected.
[0052] Next, the LED ON times of respective colors are determined.
[0053] In step S 1002 , only the R-LED is turned on for predetermined ON time T0 within which the scan signal level from the monochrome image sensor 102 does not exceed a reference level set in the AFE circuit 201 , and light reflected by the white reference plate is scanned by the monochrome image sensor 102 .
[0054] It is checked in step S 1003 if the scanned signal level has reached the reference level. As a result, the scanned signal level has not reached the reference level, the flow advances to step S 1004 to increment an R-LED ON time by a predetermined value ΔT, and light reflected by the white reference plate is scanned again. In this way, the ON time is gradually increased, and if it is determined that the reference level has been reached, the LED ON time at that time is set as an ON time upon scanning an image for one line of the R-LED.
[0055] The ON times of the remaining G-, B-, and E-LEDs are determined by substantially the same processes. That is, steps S 1006 to S 1009 are processes for determining the ON time of the G-LED, steps S 1010 to S 1013 are processes for determining the ON time of the B-LED, and steps S 1014 to S 1017 are processes for determining the ON time of the E-LED.
[0056] After the ON times of the LEDs of all the color components are determined, the flow advances to step S 1018 to scan light reflected by the white reference plate for the LED ON times determined in correspondence with R, G, B, and E, and white shading correction data is output to and is stored and held by the host computer 300 .
[0057] The processes executed when the scan mode is the “32-bit multi-valued” mode have been explained. In the “24-bit multi-valued” mode, the processes in steps S 1014 to S 1017 are skipped since they are not required. In the “binary” mode, the processes in steps S 1002 to S 1005 and S 1010 to S 1017 are skipped since only the G-LED is turned on and these processes are not required.
[0058] Step S 805 in FIG. 2 has been explained. Upon completion of the setups of the LED ON time data and shading correction data, the flow advances to step S 806 .
[0059] In step S 806 , a pre-scan is executed. The pre-scan is a preliminary scan operation, and scans a document image at a resolution lower than a final scan (main scan) so as to inform the user of an overview of the scanned image to some extent. Hence, the scan speed in the pre-scan (the moving direction of the CIS 101 in the sub-scan direction) is higher than that in the main scan.
[0060] This scan process will be explained below with reference to the timing chart in FIG. 8 .
[0061] The R-LED is turned on while moving the CIS 101 in the sub-scan direction, and the monochrome image sensor 102 scans a document to be scanned only for one line. That is, red light reflected by the document to be scanned is accumulated on the monochrome image sensor 102 . Upon completion of the accumulation time for one line, the G-LED is turned on in turn. During this period, the scan signal for one line in the main scan direction of the R component accumulated so far is output from the monochrome image sensor 102 as an output signal, which is output to the host computer 300 via respective circuits. Likewise, the B-LED is turned on, and G data is output during the B accumulation time. After that, the E-LED is turned on, and B data is output during the E accumulation time. Upon completion of the ON time of the E-LED, the CIS 101 has moved by a width for one line in the sub-scan direction from the ON start position of the R-LED. The R-LED is turned on to scan the next line. The E component data for the current line is output during the ON time (accumulation time) of the R-LED for the next line.
[0062] As a result, in the scan process in the scan mode (32-bit multi-valued mode) using the four, i.e., R, G, B, and E LEDs, when the CIS 101 is located at a given position, R, G, B, and E data are output to the host computer 300 for one line. In the binary scan mode, every time a G component for one line is scanned, the CIS 101 is moved by a 1-line width in the sub-scan direction.
[0063] The aforementioned processes are executed until it is determined in step S 807 that scans for designated lines are complete. As a result, the user can confirm an overview of a pre-scanned document image on the host computer 300 .
[0064] It is then checked in step S 808 if a main scan request command is received. Upon reception of this request command, a scan process for one line is executed in step S 809 , and this process is repeated until it is determined in step S 810 that the scan processes for designated lines are complete. The differences between the main scan and pre-scan are as follows. That is, the main scan scans according to the scan resolution set by the user, while the pre-scan scans by decreasing the number of data per line compared to the main scan by decimating appropriate pixel signals output from the monochrome image sensor 102 . Also, the main scan narrows down the 1-line width of movement of the CIS 101 in the sub-scan direction than that in the pre-scan. In other words, the main scan scans at a higher resolution, while the pre-scan scans at a relatively lower resolution since an overview of an image need only be recognized.
[0065] The image scanning device of this embodiment has been explained. The processes in the image processing circuit 203 in this embodiment will be explained below.
[0066] FIG. 5 is a block diagram showing principal part of the image processing circuit 203 in this embodiment.
[0067] A color correction processor 801 multiplies raw image data scanned by the image scanning device of this embodiment by color correction processing coefficients according to the selected scan mode (to be described in detail later). A tone adjustment processor 802 adjusts lightness. An effect processor 803 applies effect processes for improving image quality such as an edge emphasis process, noise reduction process, and the like, and outputs a final image.
[0068] The color correction processor 801 will be described in more detail below.
[0069] The pre-scan or main scan instruction request and the scan mode designation are received from the host computer, as has been described above. This scan mode is also set in the color correction processor 801 . This is to attain matching between the sender side (image scanning device) of image data and the receiver side (scanner driver).
[0070] If the scan mode is the binary mode, since one pixel is expressed by 1 pixel, the tone adjustment processor 802 and effect processor 803 do not execute any processes, and image data is directly output.
[0071] On the other hand, if the 24-bit multi-valued mode is set as the scan mode, the color correction processor 801 executes the following processes. In the following description, Rc, Gc, and Bc indicate corrected data, and data without any suffixes indicate data from the shading correction circuit 202 .
Rc= 0.927 ×R+ 0.177 ×G− 0.104 ×B
Gc=− 0.013 ×R+ 1.204 ×G− 0.191 ×B
Bc=− 0.023 ×R− 0.049 ×G+ 1.072 ×B (1)
[0072] The above equations will be explained in more detail. As described above, the LEDs as the R, G, and B light sources in this embodiment respectively have dominant emission wavelengths of 630 nm (R LED), 525 nm (G LED), and 470 nm (B LED), as shown in FIG. 3 . By contrast, in the luminousity characteristics of human eyes, the barycentric position of R component sensitivity is approximately 620 nm, that of G component sensitivity is approximately 545 nm, and that of B component sensitivity is approximately 450 nm, resulting in differences between color components of the human eye and LEDs.
[0073] In other words, it is desired to shift the wavelength of an R component obtained from the shading correction circuit 202 toward the short wavelength side, that of a G component toward the long wavelength side, and that of a B component toward the short wavelength side.
[0074] However, R, G, and B data output from the shading correction data 202 do not include any wavelength components by now but include only their light-receiving intensities. Hence, data of the color components R, G, and B are considered as wavelength data since the magnitude relationship of their wavelengths meet B<G<R, and correction substantially equivalent to movement of their barycentric positions is attained by multiplying R, G, and B by weighting coefficients and adding/subtracting them to/from each other, i.e., operating R, G, and B as composite wavelength components. That is, in order to shift an R component toward the short wavelength side, the data value of an input R component is decreased, and values to be added to G and B components are increased. In order to shift a G component toward the long wavelength side, the ratio of increasing the G component is set to be large, and the ratio of subtracting the value of a B component is set to be large. Equations (1) above are derived as a result of examinations of various corrections and color reproducibilities on the basis of consideration of such correlation among R, G, and B. According to equations (1) above, it was demonstrated that the LED luminous spectrum characteristics shown in FIG. 3 become nearly equivalent to those which have undergone correction shown in FIG. 6 .
[0075] As shown in FIG. 6 , since the ratio of the red component that becomes involved with the green component increases, the same effect as that obtained when the barycentric position of the luminous spectrum characteristics (luminous spectrum distribution) of the R component shifts (moves) toward the short wavelength side is obtained. Also, the same effect as that obtained when the G component shifts (moves) toward the long wavelength side, and the same effect as that obtained when the B component shifts (moves) toward the short wavelength side are obtained. That is, after the arithmetic operations of equations (1), the barycentric positions of the R, G, and B components have moved to the vicinities of 620 nm, 530 nm, and 470 nm, and the characteristics approximate to CIE-RGB shown in FIG. 4 can be obtained. As described above, by making the arithmetic operations given by equations (1), upon scanning in the 24-bit multi-valued mode, color reproducibility higher than that obtained without any correction can be obtained.
[0076] On the other hand, if the 32-bit multi-valued mode is set, the color correction processor 801 converts data of color components R, G, B, and E into R, G, and B component data that can be used by the personal computer via equations (2) below. In equations (2), data with suffixes “c” indicate converted data, and data without any suffixes indicate input color component data.
Rc= 0.947 ×R+ 0.192 ×G− 0.119 ×B− 0.018 ×E
Gc=− 0.020 ×R+ 1.972 ×G+ 0.031 ×B− 0.983 ×E
Bc=− 0.023 ×R+ 0.127 ×G+ 1.080 ×B− 0.184 ×E (2)
[0077] FIG. 10 shows the luminous spectrum characteristics equivalent to these conversion results. As shown in FIG. 10 , since the E-LED is used, and the correction based on equations (2) is applied, the barycentric position of the red luminous spectrum characteristics shifts toward the short wavelength side, and can become closer to that of the luminous spectrum characteristics of a red component of CIE-RGB compared to the correction of equations (1). As for a green component, an emerald wavelength component of the green component is largely subtracted, as can be seen from FIG. 10 . Furthermore, the half wavelength of the green component on the short wavelength side shifts from the vicinity of 500 nm to that of 510 nm, and the barycentric position of the luminous spectrum characteristics shifts toward the long wavelength side and tends to be closer to that of the luminous spectrum characteristics of the green component of CIE-RGB.
[0078] As described above, in the 32-bit multi-valued image scan mode using the four, i.e., R, G, B, and E LEDs, the LED luminous spectrum characteristics can be precisely approximate to those of CIE-RGB, thus further improving the color reproducibility.
[0079] In this embodiment, the four-color scan mode is made in the order of R, G, B, and E as shown in FIG. 8 upon focusing attention on one line to be scanned for the following reason.
[0080] E component data described in this embodiment has a large overlap wavelength range with the G component of the R, G, and B components, as can be seen from FIG. 12 . That is, the E component data has a highest correlation coefficient with the G component. When conversion from four colors into three colors based on equations (2) is made, G component data after three-color conversion is mainly generated from G and E components before conversion. Also, the human eye have a highest spectral luminous efficacy with respect to the G component which includes a wavelength of 555 nm as nearly the center of the visible light range.
[0081] FIG. 16A shows a case wherein E and G components are scanned successively, and FIG. 16B shows a case wherein E and G components are scanned every other colors. As shown in FIG. 16A , when E and G components are successively scanned, the sampling period in the sub-scan direction with respect to colors in the overlap wavelength range of the E and G components becomes equal to those of R and B components. However, when the E and G components are scanned every other colors, the sampling period in the sub-scan direction is raised with respect to colors in the overlap wavelength range of the E and G components.
[0082] In this way, since the control is made not to successively scan a G component to which the human eye has a highest spectral luminous efficacy and an E component having high correlation with the G component and having a second highest spectral luminous efficacy, i.e., to scan E and G components every other color components, the resolution in the sub-scan direction can be improved with respect to colors in the overlap wavelength range of the E and G components. Therefore, as the scan order of respective color components, an R or B component is preferably scanned between G and E components. More specifically, the control is preferably made to scan by turning on the color LEDs in the order of R, G, B, and E described in this embodiment or in the order of R, E, B, and B.
Second Embodiment
[0083] In the first embodiment, the color correction processes in the three-color scan mode and four-color scan mode are executed on the image scanning device side. Alternatively, the scanned R, G, and B or R, G, B, and E component data may be output to the host computer, which may execute the correction processes. When the correction processes are done on the host computer side, that correction function can be added to an image scanner driver which runs on the host computer. As a result, the edit processes that can obtain the effects of the above embodiment can be made without modifying a normal image processing application.
[0084] An implementation example of the color correction processes by a scanner driver on the PC 300 side will be explained hereinafter as the second embodiment.
[0085] The structure of the image scanning device is the same as that shown in FIG. 7 . However, when the 32-bit multi-valued mode is set, the image scanning device directly outputs 8-bit data of R, G, B, and E components to the PC 300 .
[0086] FIG. 13 is a functional block diagram of a part that pertains to image reception of a scanner driver which runs on the host computer 300 in this modification (a GUI part used to issue commands to the image scanning device, and a processing part that pertains to transmission of LED ON time data and shading correction data are not shown).
[0087] A color correction processor 1101 multiplies raw image data scanned by the image scanning device of this embodiment by color correction processing coefficients according to the selected scan mode (to be described in detail later). A tone adjustment processor 1102 adjusts lightness. An effect processor 1103 applies effect processes for improving image quality such as an edge emphasis process, noise reduction process, and the like, and outputs a final image to an application as a read source (in general, an image edit application or the like).
[0088] The color correction processor 1101 will be described in more detail below.
[0089] Upon transmitting the pre-scan or main scan instruction to the image scanning device, the scan mode is set in the image scanning device, as has been described above. This scan mode is also set in the color correction processor 1101 . This is to attain matching between the sender side (image scanning device) of image data and the receiver side (scanner driver).
[0090] If the scan mode is the binary mode, since one pixel is expressed by 1 pixel, the tone adjustment processor 1102 and effect processor 1103 do not execute any processes, and image data is directly output to an application.
[0091] On the other hand, if the 24-bit multi-valued mode (three-color LED scan mode) or 32-bit multi-valued mode (four-color LED scan mode) is set as the scan mode, the color correction processor 1101 executes the following processes. In the following description, Rc, Gc, and Bc indicate corrected data, and data without any suffixes indicate raw data from the image scanning device.
In case of 24-bit multi-valued mode:
Rc= 0.927 ×R+ 0.177 ×G− 0.104 ×B
Gc=− 0.013 ×R+ 1.204 ×G− 0.191 ×B
Bc=− 0.023 ×R− 0.049 ×G+ 1.072 ×B (3)
In case of 32-bit multi-valued mode:
Rc= 0.947 ×R+ 0.192 ×G− 0.119 ×B− 0.018 ×E
Gc=− 0.020 ×R+ 1.972 ×G+ 0.031 ×B− 0.983 ×E
Bc=− 0.023 ×R+ 0.127 ×G+ 1.080 ×B− 0.184 ×E (4)
[0094] As a result of the above processes, in either of the 24- or 32-bit multi-valued mode, conversion to three primary colors, i.e., R, G, and B data expressed by a personal computer or the like is made.
[0095] FIG. 15 is a flowchart showing an example of the reception process of image data in the scanner driver program of this embodiment.
[0096] It is checked in step S 1 if the scan process has been made in the binary scan mode. If it is determined that the scan process has been made in the binary scan mode, the flow advances to step S 2 to receive binary data for one line. In step S 3 , the binary data is output to an application which has launched this scanner driver.
[0097] On the other hand, if it is determined that the scan process has been made in the three- or four-color LED scan mode, R, G, and B data for one line are received and are stored in an appropriate area of a RAM of the host computer in steps S 4 to S 6 . If the three-color LED scan mode is determined in step S 7 , the flow advances to step S 8 to apply the correction processes based on equations (3) above. On the other hand, if the four-color LED scan mode is determined, the remaining E data is received in step S 9 , and the correction processes based on equations (4) above are applied in step S 10 .
[0098] After that, tone adjustment is applied in step S 11 , and the effect process is applied in step S 12 . In step S 13 , the R, G, and B data are output to the application which has launched this scanner driver.
[0099] In this manner, image data for one line is output to the application. It is checked in step S 14 if data for the number of lines designated by the scan instruction have been received. If NO in step S 14 , the processes in step S 1 and subsequent steps are repeated.
[0100] The present inventors confirmed the presence of the following differences in association with the color reproducibility of R, G, and B, three-primary-color scanned image data and that of four-color scanned image data.
[0101] Image data, which are obtained by scanning “IT8 chart” normally used for color calibration of input and output devices in the 24- and 32-bit multi-valued modes using the image scanning device of this embodiment, are corrected by the aforementioned processes to generate R, G, and B image data of three, R, G, and B components, and the R, G, and B image data are converted into image data on the Lab color space via the XYZ color space. Color conversion colors used in this case are as follows (note that the light source is of D65 type):
X= 0.4124 ×Rc+ 0.3576 ×Gc+ 0.1805 ×Bc
Y= 0.2126 ×Rc+ 0.7152 ×Gc+ 0.0722 ×Bc
Z= 0.0193 ×Rc+ 0.1192 ×Gc+ 0.9505 ×Bc
L= 116×( Y/Y 0) 0.333 −16
a= 500×[( X/X 0) 0.333 −( Y/Y 0) 0.333 ]
b= 200×[( Y/Y 0) 0.333 −( Z/Z 0) 0.333 ] (5)
for X0=0.95045, Y0=1.0, and Z0=1.08906.
[0103] A color difference ΔE is calculated from the L, a, and B image data calculated using equations (5) and the colorimetric values of the IT8 chart. The color difference ΔE is given by:
Δ E =( ΔL 2 +Δa 2 +Δb 2 ) 1/2
where ΔL, Δa, and Δb are the differences between the image data obtained by the image scanning device of this embodiment, and calorimetric data of a document.
[0104] FIG. 14 shows the comparison results of representative colors (red, green, blue, emerald, magenta, yellow) of the color differences ΔE of the three- and four-color scan modes, which are calculated by the above formula. As shown in FIG. 14 , red, green, and blue have substantially no differences or small differences between the three- and four-color scan modes. However, emerald, magenta, and yellow have smaller color differences in the four-color scan mode than the three-color scan mode. Especially, as seen easily, “emerald (E component)” as the fourth light-emitting member has a large difference, and the four-color scan mode has higher color reproducibility.
[0105] In the above example, in the three- and four-color scan modes, the host computer performs conversion and correction to R, G, and B data. Alternatively, the image scanning device may perform such conversion and correction. In this case, the load on the image scanning device becomes heavier and line buffers for four colors (required to calculate R. G, and B data) must be added. However, the host computer can exploit an existing three-color scanner driver. Note that since the existing scanner driver cannot designate the four-color scan mode, a control panel or the like equipped on the image scanning device must be used to designate that mode.
[0106] As described above, according to this modification, the image scanning device shown in FIG. 11 and the host scanner driver program on the host computer 300 can obtain an image with high color reproducibility. Hence, since the scanner driver program on the host computer implements the aforementioned processes, the scope of the present invention includes such computer program. Normally, since the computer program is stored in a computer-readable storage medium such as a CD-ROM or the like, which is set in a reader of the computer, and is ready to run when the program is copied or installed in the system, the scope of the present invention also includes such computer-readable storage medium.
Third Embodiment
[0107] A case will be explained below wherein the transmitting document illumination unit 210 (see FIG. 7 ) is used. The transmitting document illumination unit 210 includes four LEDs, i.e., R, G, B, and E LEDs if it is applied to the first embodiment.
[0108] Nowadays, a four-layered silver halide film to which a color sensitive layer sensitive to emerald is added in addition to red, green, and blue color sensitive layers is commercially available, as disclosed in Japanese Patent Laid-Open No. 2003-84402. Since the transmitting document illumination unit 210 of this embodiment includes four, R, G, B, and E light sources (LEDs) as in the above description, it scans a transmitting document of such four-layered silver halide film, thus obtaining a scanned image with higher color reproducibility.
[0109] FIG. 11 is a sectional view when the transmitting document illumination unit 210 is connected to the interface 208 of this device via a cable 230 . In FIG. 11 , reference numeral 220 denotes a film holder which holds a film to be scanned. The film holder has an opening (not shown) for one frame of the film, and the transmitting document illumination unit 210 is set above the holder. The transmitting document illumination unit 210 includes an R light-emitting LED 210 R, G light-emitting LED 210 G, B light-emitting LED 210 B, and E light-emitting LED 210 E, one of which is turned on as in the optical waveguide 104 . Reference numeral 211 denotes a panel which two-dimensionally, uniformly emits light upon emission of light by each LED, and has a size at least larger than that of one frame of the film. Since details of alignment and the like between the film holder and transmitting document illumination unit are explained in Japanese Patent Laid-Open No. 2004-7547 that has already proposed by the present applicant, a description thereof will be omitted.
[0110] Upon detection of connection of the transmitting document illumination unit 210 to this device (an appropriate switch is provided to the interface 208 , and detection is made based on the state of that switch), the controller 200 disables the optical waveguide 104 , and determines the transmitting document illumination unit 210 as an object to be driven.
[0111] Since the actual scan process is substantially the same as that in the above embodiment except that the LEDs in the optical waveguide light source 104 are switched to those of the transmitting document illumination unit 210 , and movement in the sub-scan direction is made in correspondence with the film size, a description thereof will be omitted.
[0112] As described above, upon scanning a four-layered silver halide film or the like to which a color sensitive layer sensitive to emerald is added in addition to normal R, G, and B color sensitive layer, the scan process of this embodiment can be performed by sufficiently utilizing the film characteristics, thus obtaining a scanned image with higher color reproducibility.
[0113] Note that the image scanning device of this embodiment has exemplified an image scanner as a peripheral device of the host computer, but may be applied to a document scanner of a copying machine. When the image scanning device of this embodiment is applied to the copying machine, a print process is made after conversion RGBE→RGB→YMCK.
[0114] In this embodiment, the contact image sensor (CIS) has been exemplified. However, since the present invention can be applied to a device using a CCD, the present invention is not limited to the aforementioned specific embodiments. Furthermore, the present invention can be applied to not only a device that scans a document image using four colors, but also a device that scans a document image using five or more colors. As described above, according to the present invention, the color reproducibility of a scanned image can be improved compared to the conventional document scan process using R, G, and B light-emitting members.
[0115] As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the claims.
CLAIM OF PRIORITY
[0116] This application claims priority from Japanese Patent Application Nos. 2004-031404 and 2004-031405, both filed on Feb. 6, 2004, which is hereby incorporated by reference herein.
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This invention provides a technique which allows more faithful color reproduction by a relative simple arrangement. To this end, according to this invention, by time-divisionally driving R, G, B, and E LEDs respectively having dominant emission wavelengths of 630 nm, 525 nm, 470 nm, and 500 nm, a common monochrome line image sensor ( 102 ) scans a document image. Scanned image data of respective color components undergo correction equivalent to that attained by shifting the barycentric positions of respective wavelength distributions so as to become closer to the CIE-RGB sensitivity distributions.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part application of pending U.S. patent application Ser. No. 09/446,352, which is hereby incorporated by reference in its entirety.
FIELD AND BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to the field of immunology and control of host defense mechanisms. More specifically, this invention relates to the use of VPAC1R, VPAC2R, and PAC1R agonists, that can be administered in therapeutically effective doses to treat and/or prevent septic shock.
[0003] Despite recent progress in antibiotics and critical care therapy, sepsis is still associated with a high mortality rate. Septic shock and sequential multiple organ failure/multiple organ dysfunction syndrome (MOF/MODS) correlate with poor outcome.
[0004] Lipopolysaccharide (LPS) or endotoxin plays a pivotal role in the initiation of a variety of host responses caused by Gram-negative bacterial infection (See, J. E. Parrillo, New England Journal of Medicine 1993, 328:1471). Since the 1980s, novel insights into the molecular pathogenesis of LPS-induced shock (endotoxic shock) and organ dysfunction have been gained. The molecular cloning of proinflammatory cytokines and adhesion molecules were important steps towards understanding the molecular mechanism of sepsis. In addition, nitric oxide (NO) has been identified as a key mediator of LPS-mediated hypotension (See, L. L. Moldawer, Critical Care Medicine 1994, 22:3).
[0005] In 1991, a new concept known as Systemic Inflammatory Response Syndrome (SIRS) was postulated to define the state of patients who exhibit a systemic response to inflammatory episodes. SIRS is diagnosed by a combination of available clinical signs and symptoms. Currently, sepsis is generally defined as SIRS induced by infection.
[0006] No world-wide statistics on the occurrence of sepsis are available. In the United States alone, however, it is estimated that there are 300,000-500,000 septic episodes each year, with mortality rates ranging from 20% to 40%. Refractory hypotension (septic shock) is the main cause of death within a few days of the onset of sepsis. Later, MOF/MODS becomes the primary clinical problem and main cause of mortality. Once a patient develops septic shock or sequential MOF/MODS, the mortality rate increases to 60-70%.
[0007] Gram-negative bacteria are responsible for 45-60% of sepsis caused by bacterial infection when mixed-organism infections are included (See, R. Karima et al., Molecular Medicine Today 1999, 5:123). A variety of pathophysiological responses in various tissues and organ systems occur during endotoxemia. In particular, circulatory failure, leukocyte-induced tissue injury and activation of coagulation systems appear to be critical determinants in the development of sequential organ failure.
[0008] A number of mediators derived from host cells are responsible for most of the manifestations of endotoxemia. The proinflammatory cytokines, including tumor necrosis factor alpha (TNFα), interleukin (IL) 1β, IL-6, IL-8 and IL-12, and interferon gamma (IFNβ), play a critical role in the inflammatory responses. Nitric oxide (NO) is now known to induce a variety of responses in addition to hypotension.
[0009] Furthermore, anti-inflammatory mediators, such as IL-10 and IL-1 receptor antagonist (IL-1Ra), also contribute to the modulation of inflammatory responses in endotoxemia.
[0010] TNFα is produced by several types of cells that include monocytes and macrophages, T and B lymphocytes, neutrophils, mast cells, tumorous cells, and fibroblasts. It is an important regulatory factor in other pro-inflammatory cytokines, such as IL-1β, IL-6, and IL-8. TNFα induces the expression of adhesion molecules in endothelial cells, activates leukocytes to destroy the microorganisms, acts on the hepatocytes to increase the systhesis of serum proteins which contribute to the acute phase response and activate the coagulation system. Overproduction thereof leads to immunopathologic diseases, autoimmunity and inflammation.
[0011] IL-6 is a multi-functional cytokine produced both by lymphocytes and non-lymphoid cells. It regulates several aspects of the immune response, such as the production of proteins that mediate acute phase and hematopoiesis. Furthermore, it acts as a mediator in inflammatory response. Its production is regulated by several factors, which include TNFα, IL-1, and LPS.
[0012] Nitric oxide (NO) is an unstable free radical gas that mediates many physiological and toxic functions, such as macrophage cytotoxicity, neurotransmission, neurotoxicity, and regulation of blood pressure. Induced NO production is one of the principal mechanisms of macrophage cytotoxicity for tumor cells, bacteria, protozoa, helminthes and fungi.
[0013] In general, production of NO follows a generalized or localized inflammatory response resulting from infection or tissue injury. Despite its beneficial role in host defense, sustained NO production can be deleterious to the host. Nitric oxide synthesis induced by cytokines and/or inflammatory stimuli has been implicated in experimental arthritis, inflammatory bowel disease, hypotension associated with septic shock, and other types of tissue injury.
[0014] IL-12, another early proinflammatory cytokine secreted by macrophages activated by microbial products, plays a central role in the regulation of cell-mediated immunity. IL-12 stimulates the proliferation of activated T lymphocytes and enhances IFNγ secretion by NK cells and T lymphocytes. Consistent with the latter effect, IL-12 has a pivotal role in the induction of CD4 + Th1 cell responses, acting in antagonism to IL-4, the major promoter of the Th2 response. In mice, IL-12 plays a decisive role in the protection against intracellular pathogens, including parasites and bacteria.
[0015] However, the central importance of IL-12 and IFNY in the pathogenesis of the endotoxic shock is indicated by the fact that pretreatment with corresponding neutralizing antibodies protects against lethality.
[0016] IL-10, one of the major anti-inflammatory cytokines, was initially described as a Th2 product that inhibits the secretion of Th1-derived cytokines, through the down-regulation of the antigen-presenting function of professional antigen presenting cells. In addition to T cells, activated monocytes/macrophages serve as a major IL-10 source, especially in response to LPS stimulation. IL-10 inhibits several macrophage functions, such as oxidative burst, phagocytosis, nitric oxide production, and cytokine production. Administration of IL-10 to endotoxic mice showed protective effects against proinflammatory cytokine production and lethality.
[0017] Strategies of neutralization of the pro-inflammatory cytokines have been tested in the treatment of endotoxic shock but the results do not indicate that there is a greater long-term survival (See, G. Zaneti and M-P. Glauser, Current Opinion in Infectious Diseases 1997, 10:139).
[0018] A treatment that inhibits the production of different pro-inflammatory cytokines and mediators would represent a considerable improvement in the evolution of endotoxic shock and in the probabilities of survival.
[0019] Vasoactive intestinal peptide (VIP) was first isolated from the porcine duodenum and in 1974, Mutt and Said (See, V. Mutt et al., European Journal of Biochemistry 1974, 42:581) established the amino acid sequence. VIP contains 28 amino acid residues, with a highly conserved sequence in vertebrates, a fact that is consistent with its important biological role. It is known today that VIP is a pleiotropic peptide produced by neurons in different areas of the central and peripheral nervous system and by endocrine cells as the pituitary lactotrophes and cells of the endocrine pancreas.
[0020] The pituitary adenilate cyclese activating peptide (PACAP) is a member of the family of peptides of the secretin/VIP/glucagon, of which two molecular forms are known, namely PACAP-38 and PACAP-27, whose sequence was determined by Ogi et al (K. Ogi et al., Biochemical and Biophysical Research Comunications 1993, 196:1511). Both peptides are widely distributed in the central and peripheral nervous system.
[0021] VIP together with PACAP, secretin and GRF receptors constitute a subfamily based on the homology of both ligands and receptors. To date, three VIP/PACAP receptors have been identified to date that are membrane-bound receptors belonging to the family 2 of G protein-coupled receptors (GPCR).
[0022] The six families of (GPCR) have a common central domain constituted of seven transmembrane helices. The family 2 is characterized by a large N-terminal domain which plays an important role in the binding of the ligand, besides for VIP receptors both extracellular and transmembrane domains are also involved. The three VIP/PACAP receptors cloned are: the VPAC1 and VPAC2 that bind VIP and PACAP with equal affinity (See, T. Ishihara et al., Neuron 1992, 8:811; and, A. Covineau et al., Biochemical and Biophysical Research Comunications 1994, 200:769), and the PAC1 receptor that is PACAP selective, although in micromolar amounts, VIP is a heterologous ligand (A. J. Harmar et al., Pharmacological Reviews 1998, 50:265), with eight variants to date produced from alternative splicing of the transcript.
[0023] VPAC1, VPAC2, and PAC1 receptors primarily stimulate the adenylate cyclase (AC) pathway. However, it has also been demonstrated only in transfected cell systems, at high expression levels, that VPAC1 may stimulate an inositol triphosphate (IP)/PLC system, as well as cause an increase of intracellular calcium levels.
[0024] There is some suggestion that, in a transfected cell system, VPAC2 will also stimulate IP synthesis. However, a clear link to the PLC/IP system remains to be found.
[0025] Seven splice variants of the PAC1 receptor are involved in the activation of both AC and IP/PLC systems, and the eighth PAC1 receptor variant, which is also a CGRP receptor, not linked to AC or IP/PLC systems, but that activates an L-type calcium channel.
[0026] VPAC1, VPAC2 and PAC1 receptors are expressed in different cell populations in both central nervous system and peripheral tissues.
[0027] VPAC1 receptor has been identified in murine isolated thymocytes and T and B lymphocytes from spleen and lymph nodes (See, R. P. Gomariz et al., Biochemical and Biophysical Research Comunications 1994, 203:1599) and also in lymphocytes and macrophages from peritoneal suspensions (See, M. Delgado et al., Regulatory Peptides 1996, 62:161).
[0028] VPAC2 receptor was described for the first time as a VIP helodermin-preferring receptor in the human lymphoma cell line SUP T1 (See, P. Roberech et al., Regulatory Peptides 1989, 26:117). VPAC2 expression is inducible in lymphocytes and macrophages. Thus, VPAC2 is detected only following stimulation through the TCR-associated CD3 molecule in lymphocytes or LPS in macrophages (M. Delgado et al., Journal of Neuroimmunology 1996, 68:27).
[0029] Moreover, VPAC2 receptor is detected in mononuclear cells by immunohistochemical techniques two days after the detection of VPAC1 at sites of inflammation and antigen recognition (H. B. Kaltreider et al., American Journal of Respiratory Cell and Molecular Biology 1997, 16:133). However, VPAC2 receptor is the only receptor of VIP/PACAP family receptors expressed in some murine T cell lines and in human lymphoid cell lines the constitutive expression of VPAC2 receptor has been reported.
[0030] The best characterization of VIP effects exerted through the interaction VPAC1 and VPAC2 in the immune system is the adenylate cyclase pathway.
[0031] PAC1 receptor is expressed only in macrophages, as lymphocytes lack PAC1 expression (See, M. Delgado et al., Journal of Neuroimmunology 1996, 68:27; and, D. Pozo et al., Biochemical and Biophysical Acta 1997, 1359: 250). Although PAC1 receptor is the PACAP selective receptor that binds PACAP with greater affinity (from 100-1000 times more) than VIP (See, A. J. Harmar et al., Pharmacological Reviews 1998, 50:265) especially in central nervous system, the PAC1 expressed in freshly isolated macrophages possess similar affinity for both VIP and PACAP (See, D. Pozo et al., Biochemical and Biophysical Acta 1997, 1359: 250-52) and is coupled to the IP/PLC system.
SUMMARY OF THE INVENTION
[0032] It is an object of the present invention to provide a method to treat and/or prevent septic shock in an individual.
[0033] It is another object of the invention to provide a treatment that inhibits the production of different pro-inflammatory cytokines and mediators in humans.
[0034] A still further object of the present invention is to provide a method for administering a therapeutically effective amount of a VPAC1, VPAC2, or PAC1 receptor agonist together with a pharmaceutically acceptable carrier for treatment of septic shock.
[0035] Yet another object of the invention is to provide pharmaceutical compositions containing VPAC1, VPAC2 or PAC receptor agonist for treatment of septic shock in humans.
[0036] Accordingly, a method of treating septic shock is provided in which a therapeutically effective amount of a VPAC1, VPAC2, or PAC1 receptor agonist is administered to a person.
[0037] The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] In the drawings:
[0039] [0039]FIG. 1 shows the Northern blot analysis for the presence of mRNA corresponding to TNFα and IL-6 in macrophages stimulated with LPS in presence or absence of VIP or PACAP. BALB/c mice were injected with RPMI 1640 medium π: (none), LPS (400 mg), or LPS plus VIP or PACAP-38 (5 nmol);
[0040] [0040]FIGS. 2A & 2B show the circulating levels of TNFα and IL-6, respectively, in BALB/c mice injected with 400 μg LPS (control), or LPS plus VIP or PACAP-38 (5 nmol). Serum was collected at various time points (from 0 to 12 h), and the levels of TNFαand IL-6 protein were determined by ELISA.
[0041] [0041]FIGS. 3A & 3B show the survival of BALB/c mice injected with 400 μg of LPS and, either simultaneously or after 30 minutes, 1 or 4 hours, with 5 nmol of VIP or PACAP, respectively.
[0042] [0042]FIG. 3C shows the survival (%) versus LPS doses injected in mice treated with or without 5 nmol of VIP. Horizontal bars indicate the 95% confidence limits of LD50 determinations.
[0043] FIGS. 4 A- 4 E show the production of TNFα, IL-6, IL-12, NO, and IL-10, respectively, by BALB/c mice peritoneal macrophages stimulated with 0.5 μg/ml LPS in the absence (control) or presence of 10-8M VAPC1 or VPAC2 agonists.
[0044] FIGS. 5 A- 5 F show the circulating levels of TNFα, IL-6, IL-12, IFNY, IL-10, and NO, respectively, in BALB/c mice injected with 100 μg/mouse LPS (control), LPS plus 5 nmol/mouse VPAC1 agonist, or LPS plus 5 nmol/mouse VPAC2 agonist.
[0045] [0045]FIG. 6A shows the survival of BALB/c mice injected with 400%g of LPS at simultaneously, after 30 minutes, 1 or 4 hours, with 5 nmol of VIP, VPAC1 or VPAC2 agonist.
[0046] [0046]FIG. 6B shows the survival (%) versus LPS doses injected in mice treated with or without 5 nmol of VIP, VPAC1 or VPAC2 agonist.
[0047] [0047]FIGS. 7A & 7B show the production λ 1 of IL-6 by C57BL/6×129Sv or PAC1 −/−, respectively, mice peritoneal macrophages stimulated with 10 ng/ml LPS in the absence (control) or presence of 10 −8 M VIP or PACAP38.
[0048] [0048]FIG. 7C & 7D show the production of TNFα by C57BL/6×129Sv or PAC1−/−, respectively, mice peritoneal macrophages stimulated with 10 ng/ml LPS in the absence (control) or presence of 10 −8 M VIP or PACAP38.
[0049] [0049]FIG. 8 shows the circulating levels of TNFαand IL-6 in C57BL/6×129Sv or PAC1 −/− mice injected with 1 mg/mouse LPS, LPS plus 5 nmol/mouse VIP, or LPS plus 5 nmol/mouse PACAP38.
[0050] [0050]FIG. 9 shows the survival of C57BL/6×129Sv and PAC1 −/− mice injected with 1 mg of LPS with or without 5 nmol of VIP or PACAP38.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0051] This invention relates to the discovery of a role for VPAC1, VPAC2, and PAC1 receptor agonists in sepsis. These agonists have anti-inflammatory effects and inhibit the production of TNFα, IL-6, IL-12, IFNY, and NO, and also potenciate the production of the anti-inflammatory cytokine IL-10. These agonists can be administered in therapeutically effective doses to treat and/or prevent septic shock. The agonists of this invention typically are selected among several classes but preferably are analogs of VIP or PACAP.
[0052] As used herein, “Analogs of VIP or PACAP” means a peptide of the sequence of VIP or PACAP, or a fragment of them, or a peptide containing a part of these sequences with high affinity for VPAC1, VPAC2, or PAC1 receptors.
[0053] Further, as used herein, “Pharmaceutically acceptable” is meant to encompass any carrier, which does not interfere with the effectiveness of the biological activity of the active ingredient and that is not toxic to the host to which is administered. For example, for parenteral administration, the above active ingredients may be formulated in unit dosage form for injection in vehicles such as saline, dextrose solution, serum albumin and Ringer's solution, liposomes. Besides the pharmaceutically acceptable carrier, the compositions of the invention can also comprise minor amounts of additives, such as stabilizers, excipients, buffers and preservatives.
[0054] The administration of such active ingredient may be by intravenous, intramuscular or subcutaneous route. Other routes of administration, which may establish the desired blood levels of the respective ingredients, are comprised by the present invention.
[0055] The active ingredients of the claimed compositions herein is a VPAC1, VPAC2, or PAC1 receptor agonist. Preferably, but not exclusively, they are polypeptides analogues of VIP or PACAP that bind VPAC1, VPAC2, or PAC1 receptors with high affinity.
[0056] VPAC1, VPAC2, or PAC1 receptor agonists can be administered to an individual in a variety of ways.
[0057] The routes of administration include intradermal, transdermal (e.g. in slow release formulations), intramuscular, intraperitoneal, intravenous, subcutaneous, oral, epidural, topical, and intranasal routes. In addition the VPAC1, VPAC2, or PAC1 receptor agonists can be administered together with other components of biologically active agents such as pharmaceutically acceptable surfactants, excipients, carriers, diluents and vehicles.
[0058] For parenteral (e.g. intravenous, subcutaneous, intramuscular) administration, VPAC1, VPAC2, or PAC1 receptor agonists can be formulated as a solution, suspension, emulsion or lyophilized powder in association with a pharmaceutically acceptable parenteral vehicle (e.g. water, saline, dextrose solution) and additives that maintain isotonicity (e.g. mannitol) or chemical stability (e.g. preservatives and buffers). The formulation is sterilized by commonly used techniques.
[0059] The therapeutically effective amounts of a VPAC1, VPAC2, or PAC1 receptor agonist will be a function of many variables, including the type of agonist, the affinity of the agonist for its receptor, any residual cytotoxic activity exhibited by competitive agonists, the route of administration, the clinical condition of the patient.
[0060] Usually a daily dosage of active ingredient can be about 0.01 to 100 milligrams (mg) per kilogram of body weight. Ordinarily 1 to 100 milligrams per kilogram per day given in divided doses or in sustained release form is effective to obtain the desired results. Second or subsequent administrations can be performed at a dosage which is the same, less than or greater than the initial or previous dose administered to the individual. A second or subsequent administrations can be administered during or prior to relapse of the septic shock or the related symptoms. The terms “relapse” or “reoccurrence” are defined to encompass the appearance of one or more of symptoms of septic shock.
[0061] The present invention will now be illustrated by the following examples, which are not intended to be limiting in any way, and make reference to FIGS. 1 - 8 .
EXAMPLE 1
[0062] VIP and PACAP Inhibit the Transcription of TNFα and IL-6 in Macrophages from Mice Stimulated with LPS.
[0063] Method: BALB/c mice were injected with RPMI 1640 medium, LPS (400 μg), or LPS plus VIP or PACAP-38 (5 nmol). Peritoneal cells were harvested at 1 h (for TNFα) and 2 h (for IL-6), and total RNA was isolated from peritoneal cells. Twenty micrograms (jig) of total RNA from each sample were electrophoresed on 1.2% agarose-formaldehyde gel, transferred to nylon membranes, and cross-linked using UV light. Membranes were hybridized with specific probes for TNFα (5′-TTGACCTCAGCGCTGAGTTGGTCCCCCTTCTAGCTGGAAGACT-3′) and IL-6 (5′-CAAGAAGGCAACTGGATGAAGTCC TCTTGCAGAGAAGGAACTTCAT-3′) that were designed from the murine TNF-a and IL-6 cDNA published sequences (See, L. Fransen et al., Nucleic Acids Research 1985, 13:4417; and H. E. Grenett et al., Nucleic Acids Research 1990, 18:6455). The probe for the murine 18S RNA, as a quantity control for RNA, was an oligo-nucleotide (5′-CCAATTACAGGGCCTCGAAAGAGTCC TCTA-3′) derived from the published sequence. Oligonucleotides were 3′-labeled with digoxigenin-dUTP/dATP mix using terminal transferase, and hybridization and detection of chemoluminiscent signal were performed.
[0064] The results, as shown in FIG. 1, confirmed that VIP/PACAP significantly reduce the steady-state mRNA levels for both TNFα and IL-6 in peritoneal exudate cells. The results displayed in FIG. 1 were obtained by harvesting peritoneal cells at 1 h (for TNFα) and 2 h (for IL-6), and total RNA was prepared and subjected to Northern blot analysis using specific murine TNFα and IL-6 probes.
EXAMPLE 2
[0065] VIP and PACAP reduce the levels of circulating TNF-αand IL-6 in mice treated with LPS.
[0066] Method: BALB/c mice were injected i.p. with LPS (400 μg) (control) or with LPS and VIP or PACAP-38 (5 nmol). Blood samples were taken at various time points by cardiac puncture (from 0 to 12 h). Blood samples were allowed to clot for 1 h at room temperature and serum was obtained and kept frozen. TNFα and IL-6 levels present in serum were determined using murine-specific sandwich ELISAs.
[0067] [0067]FIGS. 2A and 2B show the levels of TNFα and IL-6, respectively, in serum following injection with each of the control and two treatments. The control test points are indicated by circles, while the test points obtained from mice injected with VIP and PACAP are shown by squares and triangles, respectively. The results shown in FIGS. 2A and 2B show that both VIP and PACAP reduced by 50-60% the levels of secreted TNFα and IL-6 in serum at the peak of the response.
EXAMPLE 3
[0068] VIP and PACAP Protect Against the Lethal Effects of LPS-Induced Septic shock.
[0069] Method: BALB/c mice were injected i.p. with LPS (400 μg) and VIP or PACAP-38 (5 nmol) at times 0, 30 min, 90 min or 4 h after LPS administration. Survival was monitored over the next 7 days. Survival curves were analyzed by the Kaplan-Meier method.
[0070] Results shown in FIGS. 3A and 3B show that mice injected with 5 nmol of VIP or PACAP and simultaneously with LPS have a survival rate near 60%. Full protective effect is exerted by VIP and PACAP even if given 1 h after LPS administration.
[0071] Also, BALB/c mice were injected i.p. with different concentrations (25-600 μg) of LPS, and survival was monitored over the next 4-7 days. Various doses of VIP were administered i.p. following injection of LPS. Control animals received only medium. Survival curves were used to calculate LD50.
[0072] The protective effect of VIP occurred over a large range of LPS concentrations, and VIP shifted the LD50 from 100 to 327 μg LPS, as shown in FIG. 3B. Test points from mice injected with VIP are shown by triangles, while control test points are shown by circles in FIG. 3B.
EXAMPLE 4
[0073] VPAC1 and VPAC2 Agonists Reduce the Secretion of Proinflammatory Cytokines and NO Production and Stimulate the Secretion of IL-10 in Macrophages Stimulated with LPS.
[0074] Method: Purified macrophages were prepared from mice following i.p. injection of 2 ml 4% thioglycollate broth. After 4 days, the mice were killed, injected i.p. with 5 ml cold DMEM, followed by the harvesting of peritoneal fluid; the peritoneal exudate cells were washed and macrophages were obtained after the elimination of T and B cells through complement-mediated lysis following treatment with anti-Thy-1 and anti-B220 mAb.
[0075] The purified macrophage preparations were approximately 96% Mac-1 +by FACS analysis. Isolated peritoneal macrophages were seeded in flat-bottom 96-well microtiter plates at 8×10 4 cells per well in a final volume of 200 μl DMEM supplemented with 2 mM L-glutamine, 100 U/ml penicillin, 10 μg/ml streptomycin and 10% FCS (complete DMEM) Cells were stimulated with 0.5 μg/ml of LPS in the absence or presence of different concentrations of VIP, VPAC1, VPAC2, or PAC1 agonists at 37 20 C. in a humidified incubator with 5% CO2. [K 15,R 16,L 27 ]VIP [1-71]-GRF [8-27] was used as VPAC1-specific agonist (Gourlet P et al.; Peptides 1997,18:1539), Ro 25-1553 Ac-[Glu 8,Lys 12,Nle 17 ,Ala 19,Asp 25, Leu 26,Lys 27,28,Gly 29,30,Thr 31 ]-VIP cyclo [21-25] was used as VPAC2-specific agonist (See, M. Xia et al., The Journal of Pharmacology and Experimental Therapeutics 1997, 281:629). Cell-free supernatants were harvested at the designated time points and kept frozen (−20° C.) until cytokine and NO determination.
[0076] The amount of IL-6, TNFα, IL-10, and IL-12 in culture supernatants were determined by using specific sandwich ELISA. The amount of NO formed was stimated from the accumulation of the stable NO metabolite nitrite by the Griess assay (See, L. Green et al., Analytical Biochemistry 1982 126:131).
[0077] As shown in FIGS. 4 A- 4 E, macrophages stimulated with LPS sequentially produced TNFα, IL-6, IL-12, NO and IL-10, respectively. In each graph of FIGS. 4 A-4E, the production levels of the respective cultures after treatment with VIP (represented by circles), VPAC1 (squares) and VPAC2 (triangles) are illustrated.
[0078] Treatment of the cultures with various concentrations of the VPAC1 agonist significantly inhibited the production of TNFα, IL-12 and NO, and stimulated IL-10 secretion in a way similar to VIP. In addition, the VPAC1 agonist reduced IL-6 production, but its effect was lower than that of VIP, showing a significant inhibitory effect only at the highest concentrations used (10 −7 -10 −6 M). On the other hand, whereas the VPAC2 agonist did not show any significant effect on IL-6 and IL-10 production, it slightly inhibited TNFα, IL-12 and NO production, although the inhibitory effects were much lower than those of the VPAC1-agonist.
EXAMPLE 5
[0079] VPAC1 and VPAC2 agonists reduce the levels of circulating proinflammatory cytokines and NO, and augment IL-10 circulating levels in LPS-induced septic shock.
[0080] Methods: BALB/c mice were injected with 100 μg of LPS. Various doses of VIP, VPAC1 agonist VPAC2 agonist or PAC1 agonist were administered i.p. either concurrently with or following injection of LPS. [K 15, R 16,L 27] VIP [1-7]-GRF [8-27] was used as VPAC1-specific agonist, Ro 25-1553 Ac-[Glu 8, Lys 12, Nle 17, Ala 19, Asp 25, Leu 26, Lys 27,28, Gly 29,30, Thr 31 ]-VIP cyclo [21-25] was used as VPAC2-specific agonist. Control animals received only medium. Blood samples were taken at various time points by cardiac puncture (from 0 to 12 h). Blood samples were allowed to clot for 1 h at room temperature and serum was obtained and kept frozen. The amount of IL-6, TNFα, IL-10, and IL-12, and IFNY levels present in serum were determined using murine-specific sandwich ELISAS. The amount of NO was stimated from the accumulation of the stable NO metabolite nitrite by the Griess assay.
[0081] FIGS. 5 A- 5 F show that, whereas both VPAC1 and VPAC2 agonists inhibited TNF-α levels in way similar to VIP, they had a much lower inhibitory effect on IL-6 levels. In each of FIGS. 5 A- 5 F, the LPS-induced levels as affected by injections of VIP, VPAC1 and VPAC2 are shown by circles for VIP, open squares for VPAC1 and triangles for VPAC2.
[0082] Mice receiving VIP, VPAC1 or VPAC2 agonists in combination with LPS showed a significant reduction in serum IL-12 and IFNγ levels. Treatment of mice with VIP, VPAC1 or VPAC2 agonists significantly enhanced the LPS-induced IL-10 level in serum, and levels were still relatively high at 12 h. The VPAC2 agonist showed a much lower stimulatory activity in comparison with the VPAC1 agonist or VIP effect.
[0083] Finally, the peritoneal injection of LPS resulted in increased No amounts in serum, with peak at 4 h, and treatment with VIP or either VPAC agonists reduced NO. The in vivo effects of VIP and both VPAC1 and VPAC2 agonists on LPS-induced TNFα, IL-6, IL-12, IFNγ, IL-10 and NO were dose dependent, showing a maximum effect at 5-10 nmol.
EXAMPLE 6
[0084] VPAC1, and VPAC2, Protect Against the Lethal Effects of LPS-Induced Septic Shock
[0085] Method: BALB/c mice were injected with different amounts (25-600 μg) of LPS, and survival was monitored over the next 4-7 days. Various doses of VIP, VPAC1 agonist VPAC2 agonist or PAC1 agonist were administered i.p. either concurrently with or following injection of LPS, at 30 min, 90 min or 4 h. [K 15, R 16, L 27]VIP[1-7]-GRF[8-27] was used as VPAC1-specific agonist, Ro 25-1553 Ac-[Glu 8, Lys 12, Nle 17, Ala 19, Asp 25, Leu 26, Lys 27,28, Gly 29,30, Thr 31]-VIP cyclo[21-25] was used as VPAC2-specific agonist. Control animals received only medium. Survival curves were analyzed by the Kaplan-Meier method.
[0086] As indicated in FIG. 6A, VPAC1 and VPAC2 agonists significantly prevented endotoxin-induced death. In FIG. 6A, test points are represented by solid circles for the control group, open squares for concurrent injections of the peptide, solid triangles for injections given at 30 minutes, open triangles for injections given at 90 minutes and solid diamonds for injections given at 4 hours.
[0087] The VPAC1 agonist exhibited a potency similar to that of VIP (approximately a survival rate of 55%), whereas VPAC2 agonist was less efficient (30% survival). The effect of both agonists was dose dependent, with doses as low as 1 nmol being partially protective.
[0088] The protective effect of the VPAC1 and VPAC2 agonists occurred over a large range of LPS concentrations, and the VPAC1 agonist, similar to VIP, shifted the LD50 from 100 to 400 μg LPS, whereas the VPAC2 agonist shifted the LD50 to 225 μg LPS, as illustrated by FIG. 6B. In FIG. 6B, control test points are shown as circles, VIP test points are shown as open squares, VPAC1 test points are shown as solid triangles and VPAC2 test points are shown as open triangles.
[0089] Even for the nonsurvivors, VPAC2 agonists significantly increased, and VIP and the VPAC1 agonist almost doubled the time until death. Kinetic studies establish that, similar to VIP, both VPAC1 and VPAC2 agonists exerted a full protective effect when given up to 30 min after LPS administration, with a partial protection even at 90 min after shock induction.
EXAMPLE 7
[0090] PAC1 Participates in the VIP/PACAP-Induced Protection from LPS-Induced Septic Shock.
[0091] Previous examples have shown that VIP and PACAP attenuate the deleterious consequences of septic shock acting through VPAC1 and VPAC2 receptors.
[0092] We have used mice deficient in PAC1 receptor (knock-out for PAC1) to elucidate the role of this receptor in the protective role of PAC1 receptor agonists in endotoxic shock.
[0093] Method: Adult male and female mice deficient in PAC1 receptor (PAC1 −/−) were obtained by gene targeting (See, F. Jamen et al., The Journal of Clinical Investigation 2000, 105:1305). PAC1 −/− mice were compared with wild type (C57BL/6×129Sv) counterparts, which serve as controls.
[0094] Macrophages elicited for 4 d with thioglicollate or resident macrophages were obtained by peritoneal lavage using 4 ml of RPMI 1640 medium. Peritoneal exudate cells were washed and resuspended in ice-cold medium supplemented with 2% heat-activated fetal calf serum containing β-ME, amino acids, penicillin, and streptomicyn. Cells were plated in 96-well tissue cultureplates at 8×10 4 cells per well in a final volume of 0.2 ml in duplicate. After 2 h at 37° C. in 5% CO2, nonadherent cells were removed by repeated washing.
[0095] At least 96% of the adherent cells were macrophages as judged by morphological and phagocytic criteria and by flow cytometry. Macrophage monolayers were incubated in RPMI 1640 complete medium and stimulated with different concentrations of LPS (10 ng/ml) in the presence or absence of VIP or PACAP38 (from 10 −12 to 10 −7 M) at 37° C. in a humidified incubator with 5% CO 2 . Cell free supernatants were harvested at the designated time points and kept frozen (−20° C.) until assayed for IL-6 and TNFα production. The amount of IL-6 and TNFα present in supernatants was determined by using specific sandwich ELISA.
[0096] FIGS. 7 A- 7 D illustrate the levels of IL-6 (FIGS. 7A & 7B) and TNFα (FIGS. 7C & 7D) in wild type and PAC1 −/− mice, respectively, assayed following treatment with VIP and PACAP compared to a control group. Test points for mice injected with LPS only (control group) are shown by circles, while those for mice injected with LPS and VIP are represented by squares and mice injected with LPS and PACAP are shown by triangles.
[0097] VIP and PACAP38 inhibited in a time dependent manner IL-6 and TNFα production in LPS stimulated macrophages from wild type mice, as shown by FIGS. 7 A- 7 D. In contrast, whereas VIP/PACAP significantly diminished, in a dose-dependent manner, endotoxin-induced TNFα levels from PAC1 −/− mice at all times assayed, both peptides failed to inhibit IL-6 production.
[0098] Mice receiving LPS (1 mg) alone or mice injected with LPS concurrently with VIP or PACAP were sacrificed after various time points. Blood was extracted by puncture and the blood samples were allowed to clot for 1 h at room temperature; serum was obtained and kept frozen until TNFα and IL-6 measurement by ELISA.
[0099] FIGS. 8 A- 8 D show the results of the ELISA measurements, with the LPS only injection control group levels represented by open bars, levels for mice injected with both LPS and VIP represented by diagonal-line shaded bars, and levels for mice injected with LPS and PACAP shown by cross-hatched shaded bars.
[0100] [0100]FIGS. 8A & 8B graphically illustrate how IL-6 levels increased slowly and remained elevated long after LPS injection in both types of mice, with a peak at 4 h. FIG. 8A shows that in wild type mice, VIP/PACAP treatment resulted in a inhibition of 30% on IL-6 levels circulating levels. However, the production of this cytokine was not affected by either peptide in PAC1 −/− mice, as seen in FIG. 8B.
[0101] [0101]FIGS. 8C & 8D shows the levels of TNFα in mice.
[0102] A sharp increase in the TNFα levels was observed within 2 h of the LPS injection in both mice types.
[0103] The addition of VIP or PACAP resulted in a reduction on the levels of circulating TNFα, with maximum values of 60%.
[0104] Wild type and PAC1−/− mice were injected i.p. with 1 mg of LPS and survival was monitored over the next 4-7 days. A 5 nmol dose of VIP or PACAP38 was administered i.p. concurrently with LPS injection. Control animals received only medium. Survival curves were analyzed by the Kaplan-Meier method.
[0105] In wild type mice, both VIP and PACAP38 protected against the lethal effect of LPS with a survival rate of 60%. However, the injection of either two peptides to PAC1 −/− mice only prevented death around 25%, as seen in FIG. 9. Survival time was twice as long in wild type in comparison to PAC1 −/− mice.
[0106] While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
1
3
1
28
PRT
unknown
Isolated from small intestines and brains of
pigs
1
His Ser Asp Ala Val Phe Thr Asp Asn Tyr Thr Arg Leu Arg Lys Gln
1 5 10 15
Met Ala Val Lys Lys Tyr Leu Asn Ser Ile Leu Asn
20 25
2
38
PRT
unknown
Isolated from ovine hypothalmi or rat brains
2
His Ser Asp Gly Ile Phe Thr Asp Ser Tyr Ser Arg Tyr Arg Lys Gln
1 5 10 15
Met Ala Val Lys Lys Tyr Leu Ala Ala Val Leu Gly Lys Arg Tyr Lys
20 25 30
Gln Arg Val Lys Asn Lys
35
3
27
PRT
unknown
Isolated from ovine hypothalmi or rat brains
3
His Ser Asp Gly Ile Phe Thr Asp Ser Tyr Ser Arg Tyr Arg Lys Gln
1 5 10 15
Met Ala Val Lys Lys Tyr Leu Ala Ala Val Leu
20 25
|
A pharmaceutical composition for the treatment and/or prevention of septic shock has VPAC1, VPAC2 or PAC1 receptor agonist combined with a pharmaceutically acceptable carrier. A method for treating or preventing septic shock is provided as well in which a therapeutically effective amount of the pharmaceutical composition is administered to a patient.
| 0
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to European Application No. EP 14179302.6, having a filing date of Jul. 31, 2014, the entire contents of which are hereby incorporated by reference.
FIELD OF TECHNOLOGY
[0002] The following relates to a method, a wind turbine and to a device for determining a yaw direction of a wind turbine. In addition, an according computer program product and a computer readable medium are suggested.
BACKGROUND
[0003] A wind turbine in operation will not always experience wind perpendicular to a rotor plane. When the rotor plane (which is also referred to as heading) of a wind turbine is not perpendicular to the wind, the efficiency will decrease. Therefore, actual wind turbines comprise a yaw system designed to automatically adjust their heading, like, e.g., rotating the rotor plane perpendicular to the incoming wind or to maintain an angle relative to the wind to maximize the surface area of the turbine rotor.
[0004] Usually, the yaw system is part of a nacelle, which may be involved in a yawing movement, i.e. being rotatable mounted on top of a tower via at least one yaw bearing. A rotor is attached to an upwind side of the nacelle. The rotor is coupled via a drive train to a generator housed inside the nacelle. The rotor includes a central rotor hub and a plurality of blades mounted to and extending radially from the rotor hub defining the rotor plane.
[0005] It is important for wind power plant operators to know an actual position or direction of the rotor plane or heading of the respective wind turbine, the plane or heading being correlated with an actual position or direction of the nacelle. The actual direction of the nacelle is also referred to as a yaw direction or a yaw position or, in relation to a predefined direction (e.g. a cardinal direction), as a yaw angle. Alternatively the yaw angle may be defined as the direction of the nacelle in relation of the direction of the incoming wind.
[0006] FIG. 1 shows in a schematically top view an exemplary scenario of a wind turbine 100 in relation to the well known cardinal points or compass points which are indicated as a compass rose in the background of FIG. 1 . A rotor hub 120 including a plurality of blades 130 defining a rotor plane 140 is mounted at the upwind side of a nacelle 110 . According to the scenario of FIG. 1 , an actual yaw direction 150 (which is also referred to as “compass heading”) of the wind turbine 100 , i.e. the actual direction of the nacelle 110 points towards the cardinal direction “North East” or “NE”. As exemplarily shown in FIG. 1 , an absolute yaw angle “θ YawAngle ” is referencing the actual yaw direction 150 of the wind turbine in relation towards the cardinal direction “North” or “N”. The absolute yaw angle θ YawAngle is indicated by an arrow 160 , wherein θ YawAngle =45°.
[0007] Information concerning the yaw direction is a common used basis for analyzing data concerning a wind turbine or performing sector management control like, e.g.,
site wind mapping and historical data collection on wind patterns, limiting wind turbine noise by avoiding operation in wind directions where noise generation is excessive, automatic curtailment and regulation of a wind turbine at yaw angles where significant wind turbulence might be present, prevention of shadow flicker/light pollution for neighboring residents or businesses at certain times of day and yaw angles, remote manual control of a wind turbine yaw position, efficiency testing and wind turbine power curve validation, or safe positioning of the rotor during ice conditions when service teams are approaching.
[0015] In order to determine, e.g., an absolute yaw angle, a wind turbine may be equipped with a yaw encoder, measuring the relative yaw direction in relation to a stationary object like, e.g., a tower being secured to a foundation at ground level. The yaw encoder is typically calibrated by determining a reference yaw direction or reference yaw angle after finalization of the wind turbine installation.
[0016] In some scenarios the initial calibration of the yaw angle is incorrect or less accurate due to applying a rough estimate or rule of thumb to determine a cardinal direction as a basis or reference for the yaw angle calibration.
[0017] A further possible reason for an inaccurate yaw angle calibration is a wind turbine installation based on a design including powerful permanent magnets, eliminating the possibility of applying magnetic compasses to determine the yaw direction or yaw angle. A magnetic compass, as a further general disadvantage, comprises inaccurateness per se, in particular at installations located at high geographic latitudes.
[0018] Alternatively, compasses based on GPS (Global Positioning System) or other satellite-based positioning systems have been applied to determine the reference yaw direction of the wind turbine.
[0019] [EP 2 599 993 A1] refers to a method to determine the yaw angle of a component of a wind turbine wherein at least one receiver of an automated and autonomous positioning system is used to generate position-data of the receiver. The receiver is arranged at a wind turbine location being subjected to a yawing movement.
[0020] However, applying such kind of automated and autonomous positioning systems for calibration issues is restricted due to high costs and limited accuracy.
SUMMARY
[0021] An aspect relates to improving the approach for determining an accurate yaw direction and/or yaw angle of a wind turbine.
[0022] A further aspect relates to a method is provided for determining a yaw direction of a wind turbine comprising the following steps,
receiving at a component of the wind turbine a signal broadcasted from a source, determining a direction from the component towards the source based on the received signal, and determining the yaw direction of the wind turbine in relation to the determined direction towards the source.
[0026] Determining the yaw direction based on a received signal broadcasted from a source can be implemented into a wind turbine in a cost effective way. As a further advantage, no active yawing movement of the wind turbine is necessary to enable the determination of the yaw direction with sufficient accuracy, i.e., the determination of the yaw direction is possible even when the wind turbine is stationary.
[0027] In an embodiment, the yaw direction is determined based on a Radio Direction Finding (RDF) method.
[0028] In another embodiment, the Radio Direction Finding method is based on a Pseudo-Doppler method. Implementing RDF based on a Pseudo-Doppler method can be implemented at a very low cost wherein the results of the RDF are based on a high quality.
[0029] In a further embodiment,
the signal is received via an antenna and/or receiver being attached to the component, the antenna and/or receiver having a calibrated 0°-direction in relation to a direction of the component, an offset angle is determined based on the calibrated 0°-direction in relation to the determined direction, and the yaw direction is determined based on the offset angle and the determined direction.
[0033] In a next embodiment,
the signal is broadcasted from the source located at a source-specific geographic position, the broadcasted signal is received at a component-specific geographic position, a relative compass heading is derived by processing the component-specific geographic position and the source-specific geographic position, and a yaw angle of the wind turbine is derived based
on the offset angle, and on the relative compass heading.
[0040] The relative compass heading or the relative cardinal direction between the receiver and transmitter of a broadcasted signal may be determined by comparing, i.e., processing respective coordinates of the geographic positions according to, e.g., triangular calculations. Such processing based on standardized geographic coordinate systems is well known and will be shortly summarized at the end of the description.
[0041] It is also an embodiment that the yaw angle is determined in relation towards a defined cardinal direction. By determining the yaw angle in relation towards a defined cardinal direction the resulting yaw direction and/or yaw angle (which is also referred to as “absolute yaw direction and/or angle”) can be determined with sufficient accuracy for each wind turbine of a wind park installation individually. As an example, the individual yaw angle/direction may be determined for each wind turbine in relation to the cardinal direction “North”.
[0042] Pursuant to another embodiment, the broadcasted signal is received at a nacelle or rotor of the wind turbine. Basically, the broadcasted signal may be received via an antenna or receiver located at any part of the wind turbine being involved in yawing or rotating movement causing a change in the direction between the antenna/receiver and the source of the signal.
[0043] According to an embodiment, the yaw direction is determined
continuously, or periodically, or within at least one defined time interval, or one-time.
[0048] As an advantage, the power consumption of the transmitter can be optimized, i.e. the waste of energy minimized. As an example, for power consumption purposes, the transmitter could be timed to broadcast the signal at regular intervals (i.e. every 24 hours) in conjunction with receivers mounted on the wind turbine.
[0049] According to another embodiment, the geographic position is defined according to
a Geographic Latitude and Longitude coordinate system, or an Universal Transverse Mercator (UTM) coordinate system, or an Universal Polar Stereographic (UPS) coordinate system.
[0053] The problem stated above is also solved by a wind turbine comprising
a receiver for receiving a signal broadcasted from a source, and a processing unit that is arranged for
determining a direction from the receiver towards the source based on the received signal, determining the yaw direction of the wind turbine in relation to the determined direction towards the source.
[0058] The problem stated above is also solved by a device comprising and/or being associated with a processor unit and/or hard-wired circuit and/or a logic device that is arranged such that the method as described herein is executable thereon.
[0059] In a further embodiment, the device is a yaw encoder.
[0060] The solution provided herein further comprises a computer program product directly loadable into a memory of a digital computer, comprising software code portions for performing the steps of the method as described herein.
[0061] In addition, the problem stated above, is solved by a computer readable medium, having computer-executable instructions adapted to cause a computer system to perform the steps of the method as described herein.
BRIEF DESCRIPTION
[0062] Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:
[0063] FIG. 1 shows in a schematically top view an exemplary scenario of a wind turbine in relation to the well-known cardinal points or compass points which are indicated as a compass rose in the background;
[0064] FIG. 2 shows an exemplary scenario of an off-shore wind park installation;
[0065] FIG. 3 exemplarily illustrates in a schematic view a basic principle of the original Doppler-RDF;
[0066] FIG. 4 illustrates in a graph a more detailed view of a sinusoidal curve representing the wavelength/frequency of a received signal according to Doppler-RDF; and
[0067] FIG. 5 shows in a block diagram a possible embodiment of a Pseudo-Doppler RDF receiver.
DETAILED DESCRIPTION
[0068] FIG. 2 shows an exemplary scenario of an off-shore wind park installation 200 thereby illustrating a determination of a yaw direction of a wind turbine according to the proposed solution.
[0069] According to the example of FIG. 2 an off-shore wind turbine 210 is located at a specific geographic position 211 . The geographic position 211 may be exemplarily defined according the UTM (Universal Transverse Mercator) coordinate system comprising a first datum or coordinate X 1 (also called “eastings”) and a second datum or coordinate Y 1 (also called “northings”).
[0070] The wind turbine 210 comprises a nacelle 216 being rotatable mounted on top of a tower 217 via a yawing system 219 . A rotor is attached to an upwind side of the nacelle 216 . The rotor includes a central rotor hub 213 and a plurality of blades 212 mounted to and extending radially from the rotor hub 213 defining a rotor plane 220 .
[0071] The nacelle 216 may be involved in a yawing movement, e.g., rotating the rotor plane 220 perpendicular to an incoming wind.
[0072] As a further exemplary member of the off-shore wind park installation 200 an electrical substation 230 is located at a specific geographic position 231 which is different from the geographic position 211 of the wind turbine 210 . The geographic position 231 may be also defined according the UTM (Universal Transverse Mercator) coordinate system comprising a first datum or coordinate X 2 and a second datum or coordinate Y 2 .
[0073] The substation 230 includes a transmitter 232 representing a source of a radio signal 233 being broadcasted to be processed with the help of a Radio Direction Finding (RDF) method.
[0074] Radio Direction Finding (RDF) refers to the determination of a direction from which a received signal is transmitted thereby using a specialized antenna or antenna system in combination with triangulation to identify the precise location or direction of a transmitter, i.e. the source of the broadcasted signal. This may exemplarily refer to radio or to other forms of wireless communication.
[0075] As shown in FIG. 2 , the signal 233 broadcasted from the transmitter 232 is received by a receiver 215 attached on top of the nacelle 216 . According to the proposed solution, the receiver 215 comprises an antenna 218 , both configured as a Radio Direction Finder or RDF receiver for finding or determining a direction towards the source 232 of the signal 233 . In the scenario 200 , the antenna 218 is configured according to a single-channel RDF system which is based on the use of a multi-antenna array in combination with the receiver 215 as a single channel radio receiver.
[0076] Thereby, the antenna array 218 may be installed or calibrated such on the top of the nacelle 216 , that a 0°-position or 0°-direction of the RDF receiver is equal to a forward facing direction of the wind turbine 210 , i.e., is in line with an actual yaw direction 214 of the nacelle 216 .
[0077] Two main categories are applicable for single-channel direction finding:
direction finding based on amplitude comparison direction finding based on phase comparison
[0080] According to an exemplary embodiment of the scenario 200 illustrated in FIG. 2 , the applied RDF method is based on a Pseudo-Doppler method (“Doppler-RDF”). Doppler-DRF is a phase-based direction finding method producing a direction estimate based on the received signal 233 by measuring a Doppler-shift induced on the signal at the antenna 218 of the RDF receiver by sampling around the elements of a circular antenna array.
[0081] FIG. 3 exemplarily illustrates in a schematic view the principle of the original Doppler-RDF using a single antenna 310 that physically moves along a circle or rotating platform 320 . In short, when the antenna 310 moves in a direction 330 towards a transmitter 350 representing a source of a signal, the antenna 310 detects a signal with a shorter wavelength, i.e. a signal with a higher frequency. On the contrary, when the antenna 310 is moving in a direction 340 away from the transmitter 350 , the antenna 310 detects a signal with a longer wavelength, i.e. a signal with a lower frequency.
[0082] Using this principle, an antenna mounted on a rotating platform as shown in FIG. 3 would detect a wavelength of the received signal which increases and decreases sinusoidal in relation to the frequency of the signal as originally emitted from the transmitter.
[0083] FIG. 4 illustrates in a graph 400 a more detailed view of a sinusoidal curve 410 representing the wavelength/frequency of a signal received via an antenna 310 as shown in FIG. 3 . Thereby, an abscissa 420 of the graph 400 is representing the angular position of the antenna 310 and an ordinate 430 is representing a Doppler-shift frequency of the received signal indicating a level of increase or decrease of the frequency of the received signal in relation to the frequency of the signal as originally emitted from the transmitter 350 .
[0084] When the antenna 310 is moving towards (i.e. towards direction 330 ) the source 350 (i.e. position “D” in FIG. 3 ), the wavelength of the received signal is at a local minimum, i.e. the Doppler-shift frequency is at a maximum (i.e. position “D” in FIG. 4 ).
[0085] When the antenna 310 is at a position nearest to the source of the signal (i.e. at position “A” in FIG. 3 ) the wavelength of the received signal is unchanged, i.e. the Doppler-shift frequency is zero (i.e. at position “A” in FIG. 4 ).
[0086] When the antenna 310 is moving away (i.e. towards direction 340 ) from the source 350 (i.e. at position “B” in FIG. 3 ) the wavelength of the received signal is at a local maximum, i.e. the Doppler-shift frequency is at a minimum (i.e. at position “B” in FIG. 4 ).
[0087] When the antenna 310 is at a position with a maximum distance to the source 350 of the signal (i.e. at position “C” in FIG. 3 ) the wavelength of the received signal is unchanged, i.e. the Doppler-shift frequency is zero (i.e. at position “C” in FIG. 4 ).
[0088] Consequently, those sections in the graph 400 without any Doppler-shift, and in particular such areas in curve 410 marking an angular position with a decreasing “zero crossing” towards the abscissa 420 (i.e. position “A” in the curve 410 ) are representing those positions of the antenna 310 closest to the source of the signal (i.e. at position “A” in FIG. 3 ). Thus, applying a decreasing zero crossing detection in graph 400 results in an accurate indication of the direction towards the source of the received signal.
[0089] In practical applications of Doppler-RDF a physically rotating disc would have to be moving at a very high rotating velocity to make the Doppler-shift “visible”. Because of this limitation, Pseudo-Doppler RDF was developed simulating the rotation of the antenna disc electronically.
[0090] FIG. 5 shows in a block diagram a possible embodiment of a Pseudo-Doppler RDF receiver 500 . Pseudo-Doppler RDF is based on an antenna array 510 including multiple antennas 511 . . . 514 . Each antenna 511 . . . 514 is connected to an antenna controller 520 . The antenna controller 520 is connected to a FM (Frequency Modulation) receiver 530 which is communicating with a demodulator 521 . The demodulator 521 is coupled to a band pass filter 532 which is connected to a zero-crossing detector 533 .
[0091] The antenna controller 520 is further connected to an antenna position selector/multiplexer 540 driven by a clocking signal unit 541 . The antenna position selector/multiplexer 540 is further coupled to a direction comparator 542 which is also communicating with the zero-crossing detector 533 . The direction comparator 542 is further communicating with an orientation output 543 indicating the resulting direction of the source of the signal received at the antenna array 510 .
[0092] According to FIG. 5 , signal reception at the antenna array 510 is rapidly shifted (indicated by a sequence “1-2-3-4” in FIG. 5 ) from antenna to antenna 511 . . . 514 driven by the antenna position selector/multiplexer 540 in combination with the controller 520 thereby simulating a single antenna rotating rapidly on a disc. As an example, for UHF (Ultra High Frequency) signals the rotation speed may be about 500 Hz.
[0093] After receiving the frequency modulated signal via the antenna array 510 and further processing via the FM receiver 530 , the received signal will be demodulated by the demodulator 531 . After demodulation, the frequency of the processed signal is equal to the frequency of the pseudo antenna rotation. After a band pass filtering via the filter 532 the positions with decreasing zero-crossings of the Doppler-shift frequency can be identified by the zero-crossing-detector 533 in combination with the direction comparator 542 . Based on the identified zero-crossings, the resulting direction from the antenna 510 towards or in relation to the source of the received signal will be indicated via the orientation output 543 .
[0094] Further, dependent from the calibration of the 0°-position or 0°-direction of the Pseudo-Doppler RDF receiver 500 , a relative offset between the 0°-position/direction, e.g. the actual yaw direction of the nacelle and the identified direction towards the source of the received signal may be also presented as a further result at the orientation output 543 .
[0095] The Pseudo-Doppler RDF receiver 500 as presented in FIG. 5 may be part of a yaw encoder of the wind turbine.
[0096] It should be noted, that each kind of Radio Direction Finding (RDF) method may be used for implementing the proposed solution.
[0097] Applying Pseudo-Doppler RDF may be the preferred solution for the following reasons:
antenna array and processor can be sourced at very low cost, antenna array can be small for UHF frequency band (15 cm×15 cm or smaller), small individual antenna length (whip style length around 19 cm for 400 MHz), high degree of accuracy (<1 degree to 5 degrees depending on design), possibility to identify beacon direction at all angles, and no direction aliasing
[0104] Regarding the signal being broadcasted, a transmitter representing the source of the signal may broadcast a steady signal at a constant reference frequency. As an example, the UHF frequency band (300 MHz to 1 GHz) may be the preferred frequency range for the broadcast due to the following reasons:
multiple UHF frequencies are available for public use, UHF allows the use of compact antenna systems (<1 m), and UHF is best for medium range line of site applications such as a large wind farms
[0108] In the following, the determination of the actual yaw direction of wind turbine according to the proposed solution will be explained in more detail.
[0109] For that, a further diagram 250 is embedded in FIG. 2 visualizing in top-view a geographical situation of the off-shore scenario 200 . At the bottom left side of the diagram 250 the nacelle 216 is indicated in top-view together with the antenna 218 located at the origin of the diagram 250 representing the geographic position 211 . Accordingly, the geographic location of the substation 230 , in particular the geographic position 231 of the transmitter 232 is indicated at the upper right side of the diagram 250 .
[0110] It should be noted, that the geographic positions 211 , 231 maybe defined according to any geographic coordinate system enabling every location on earth to be specified by a set of numbers or letters which are also referred to as coordinates. Such coordinates are often chosen such that one of the numbers represents a vertical position and two or three of the numbers represent a horizontal position. Examples for geographic coordinate systems are “Geographic latitude and longitude” or “UTM” (Universal Transverse Mercator) and “UPS” (Universal Polar Stereographic).
[0111] In the example shown in FIG. 2 , the diagram 250 is configured according to UTM wherein an abscissa 251 is exemplarily representing a cardinal direction “East” and an ordinate 252 is representing a cardinal direction “North”.
[0112] Alternatively, the abscissa 251 may represent a “Longitude” information and the ordinate 252 may represent a “Latitude” information according to the Geographic Latitude and Longitude system.
[0113] According to a first step of the proposed solution, a relative cardinal direction or a relative compass heading between the antenna or antenna array 218 of the wind turbine 210 and the transmitter 232 will be determined by comparing, i.e., processing the respective coordinates (X 1 , Y 1 , X 2 , Y 2 ) of the geographic positions 211 , 231 according to, e.g., triangular calculations. Such calculation of the relative compass heading based on a standardized geographic coordinate systems is well known and will be shortly summarized at the end of the description.
[0114] The resulting relative compass heading is indicated by an arrow 253 in the geographic diagram 250 . According to FIG. 2 , the relative compass heading 253 comprises a first coordinate (indicated by an arrow 260 ) representing the UTM-specific “eastings” and a second coordinate (indicated by an arrow 261 ) representing the UTM-specific “northings”.
[0115] The relative compass heading 253 is permanent and will never change over time as long as the wind turbine 210 , i.e. the antenna 218 and the substation 230 , i.e. the transmitter 232 will remain at the same geographic position. Therefore, the relative compass heading 253 can be calculated individually for each wind turbine one-time and be stored into a configuration file as a reference information.
[0116] In a next step, by applying the Pseudo-Doppler RDF based on the signal 233 received at the receiver 215 via the antenna 218 , the direction from the antenna 218 towards the transmitter 232 is determined.
[0117] It should be noted, that the direction from the antenna 218 toward the transmitter 232 is the same or almost the same as the direction from the nacelle 216 toward the transmitter 232 and the same or almost the same as the direction from the wind turbine 210 towards the transmitter 232 .
[0118] Further, the determined direction which is presented at the orientation output 543 of the Pseudo-Doppler RDF receiver 500 is equal or almost equal to the calculated relative compass heading 253 . Thus, the determined direction and the relative compass heading are labeled with the same index 253 in the description hereinafter.
[0119] As already mentioned above, the receiver 215 and the antenna 218 are calibrated such, that the 0°-direction is equal to the actual yaw direction 214 of the nacelle 216 .
[0120] Consequently, as a further output of the Pseudo-Doppler RDF, a nacelle offset angle θ NacelleOffset (indicated by an arrow 254 in the diagram 250 ) between the 0°-direction of the antenna 218 and the determined direction (which is equal to the calculated relative compass heading 253 ), can be derived. Based on the determined direction and the offset angle 254 the actual yaw direction (indicated by an arrow 214 in the diagram 250 ) can be determined.
[0121] Based on the offset angle 254 and/or the actual yaw direction 214 and based on the calculated relative compass heading 253 further geographic information may be derived dependent on the orientation or calibration of the geographic diagram 250 .
[0122] As an example, a reference angle θ UTM may be derived based on the relative compass heading 253 in relation to the cardinal direction “North” (indicated by the ordinate 252 ). The reference angle θ UTM is indicated by an arrow 255 in the diagram 250 .
[0123] Further, by subtracting the offset angle 254 from the reference angle 255 an absolute turbine yaw angle θ YawAngle may be derived which is specific for each wind turbine 210 being part of the wind park installation 200 . The absolute turbine yaw angle θ YawAngle is indicated by an arrow 256 in the diagram 250 .
[0124] The absolute turbine yaw angle 256 or the actual yaw direction 214 may be either updated continuously or sporadically to determine the actual yaw direction 214 or any further information concerning the actual position or direction of the rotor plane 220 or heading of the wind turbine or to calibrate the existing yaw encoder.
[0125] The proposed solution may be applicable to any wind turbines according to any of the following configurations:
front mounted rotor (Forward facing) with active yaw, rear mounted rotor (Rear facing) with active yaw, any non-traditional direction dependent rotor configurations, and any passive yaw wind turbine with a direction dependent rotor configuration
[0130] The proposed solution is independent from the design of the rotor or the nacelle, e.g., independent from the number of blades or from the shape of the nacelle.
[0131] Further, the proposed solution may be applicable to any Radio Direction Finding (RDF) method or technology capable for measuring or detecting the relative direction of a signal source.
[0132] The proposed solution may be further applicable to any embodiment of a radio transmitter as a source for broadcasting a signal at any transmission frequency. The possible range of possible frequencies to be used for the proposed solution maybe within or outside the UHF frequency band.
[0133] The proposed solution may be used for a constant or permanent monitoring of the yaw direction or yaw angle of a wind turbine or for a one-time only calibration of an existing yaw encoder.
[0134] According to a further embodiment of the proposed solution, the transmitter 232 may be configured such, that the signal 233 is broadcasted only within defined time intervals like, e.g., every 24 hours. Accordingly, the receiver 215 mounted at the wind turbine has be activated, i.e. synchronized, within the same time intervals. Beneficially, power consumption can be reduced at transmitter side as well as on receiver side.
[0135] Calculating the relative compass heading between two defined geographic positions:
[0136] Using a geographic coordinate system according to UTM:
[0137] The UTM (Universal Transverse Mercator) system of coordinates is a common system used in industry. This system breaks the globe into 60 zones each of which is then measured using meters north and east. These measurements are called “eastings” and “northings” and are designated as mE (meters east) and mN (meters north), respectively.
[0138] In nearly all cases a wind farm will exist entirely within one of the 60 zones. In the event that it falls on the border between two zones, it will be important that both the turbine and the reference point are in the same zone.
[0139] Calculating an angle from one point to another using UTM coordinates is straightforward. To determine a bearing θ, (which is corresponding with the reference angle 255 of FIG. 2 ) from the turbine coordinates (Easting 1 (i.e. X 1 in FIG. 2 ), Northing 1 (i.e. Y 1 in FIG. 2 )) to a reference coordinate (Easting 2 (i.e. X 2 in FIG. 2 ), Northing 2 (i.e. Y 2 in FIG. 2 )) the following equation can be used:
[0000]
θ
=
tan
-
1
(
Easting
2
-
Easting
1
Northing
2
-
Northing
1
)
[0140] The expression tan −1 (x) will only calculate the correct bearing when the reference coordinate is to the northeast of the turbine coordinate.
[0141] This is because
[0000]
tan
-
1
(
y
x
)
[0000] produces the same result as
[0000]
tan
-
1
(
-
y
-
x
)
.
[0142] To correct this, the common function atan2(y,x) can be used to identify which quadrant the angle is in.
[0143] The results of atan2(y,x) will show angles greater than 180° as negative numbers. To convert this result to a range from 0° to 360° the following expression can be used:
[0000] 0 360 =mod(0 deg +360, 360)
[0144] Here mod(a,b) is the modulo function that returns the remainder of a divided by b.
[0145] The only thing remaining is to make sure that the result of atan2(x,y) is converted back to degrees by using the relation below.
[0000] 180° =π radians
[0146] By combining this all it is possible to calculate the bearing θ from one UTM coordinate to the other. As an example, a line of computer code could be written as the following:
[0000] θ=mod(ATAN2(Easting2−Easting1,Northing2−Northing1)*(180/π)+360,360)
[0147] Using a geographic coordinate system according to Latitude and Longitude:
[0148] In place of using UTM coordinates, it is also possible to use the more traditional latitude and longitude coordinates. Calculating a bearing using this coordinate system is a bit more complicated; although it is still possible using simple trigonometric functions.
[0149] Approximating the earth as a sphere, the initial bearing θ from the turbine coordinate (long 1 (i.e. X 1 in FIG. 2 ), lat 1 (i.e. Y 1 in FIG. 2 )) to the reference coordinate (long 2 (i.e. X 2 in FIG. 2 ), lat 2 (i.e. Y 2 in FIG. 2 )) can be calculated using the following equation:
[0000]
θ
=
tan
-
1
(
cos
(
lat
1
)
sin
(
lat
2
)
-
sin
(
lat
1
)
cos
(
lat
2
)
cos
(
long
2
-
long
1
)
sin
(
long
2
-
long
1
)
cos
(
lat
2
)
)
[0150] However, for short distances, such as those on a wind farm, the lines of longitude around the earth can be considered to be parallel. Using this simplification the complex equation above can be simplified to the following:
[0000]
θ
=
tan
-
1
(
lat
2
-
lat
1
cos
(
lat
1
)
(
long
2
-
long
1
)
)
[0151] The expression tan −1 (x) only gives correct answers for coordinates located in the Eastern Hemisphere of the globe when using the Decimal Degree format to represent latitude and longitude.
[0152] Therefore, this function will also use atan2(y,x). Similarly, mod(a,b) is also used as before.
[0153] It is also necessary to make sure that the angle within the cos(x) function is expressed as radians and that the result of atan2(x,y) is converted back to degrees by using the relationship between degrees and radians above.
[0154] By combining this all it is possible to calculate the bearing 0 from the turbine coordinate to the reference coordinate. As an example a line of computer code could be written as the following:
[0000] θ=mod(atan2(lat 2 −lat 1 ,COS(lat 1 *π/180)*(long 2 −long 1 ))*(180/π)+360,360)
[0155] Although the invention is described in detail by the embodiments above, it is noted that the invention is not at all limited to such embodiments. In particular, alternatives can be derived by a person skilled in the art from the exemplary embodiments and the illustrations without exceeding the scope of this invention.
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A method for determining a yaw direction of a wind turbine includes the following steps, receiving at a component of the wind turbine a signal broadcasted from a source, determining a direction from the component towards the source based on the received signal, determining the yaw direction of the wind turbine in relation to the determined direction towards the source is provided. Further, a wind turbine and a device as well as a computer program product and a computer readable medium are disclosed for performing the method.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to a washing machine with a balancer, and more particularly to a washing machine, which is equipped with a balancer on a portion of the inner tub of the washing machine having a horizontally disposed drive shaft, thereby reducing its vibration and noise during a spin-drying process.
[0003] 2. Description of the Prior Art
[0004] As shown in FIG. 1, a conventional washing machine includes a cabinet 1 . A door 3 is openably mounted to the front of the cabinet 1 to allow the laundry to be fed and discharged. An outer tub 5 is situated in the cabinet 1 to accommodate water.
[0005] An inner tub 7 provided with a plurality of water passage holes 7 a is rotatably positioned in the outer tub 5 . A lifter 9 is mounted on the bottom of the interior of the inner tub 7 to raise the washing water to a predetermined height and, thereafter, allow it to fall down due to gravitational force. A water supply hose 13 passes through the cabinet 1 , and a water supply valve 11 is positioned on the water supply hose 13 , so as to supply water necessary for washing. A detergent container 15 is formed in the upper portion of the cabinet 1 to supply a detergent. A water supply bellows 17 is situated between the detergent container 15 and the outer tub 5 to supply to the outer tub 5 water that has been supplied through the water supply hose 13 and has been mixed with the detergent.
[0006] A motor 19 is mounted beneath the outer tub 5 . A belt 21 and a pulley 23 are situated in the vicinity of the motor 19 to rotate the inner tub 7 normally and reversely.
[0007] A water drain bellows 25 is situated under the outer tub 5 to drain water that is used in the washing machine. A drain pump 27 is mounted to the end portion of the drain bellows 25 to pump water that is drained through the water drain bellows 25 . A drain hose 29 is connected to the drain pump 27 to drain to the outside water pumped by the drain pump 27 .
[0008] A water level sensor 31 is positioned in the cabinet 1 so as to sense a water level by means of water pressure to determine if water is supplied to the outer tub 5 or not. A gasket 35 is interposed between the door 3 and the outer tub 5 to prevent water contained in the outer tub 5 from leaking.
[0009] Reference numerals 37 , 39 and 25 a designate a spring for supporting the upper portion of the outer tub 5 , a damper for supporting the lower portion of the outer tub 5 and reducing the vibrations of the outer tub 5 , and a drain valve, respectively.
[0010] However, in the conventional drum washing machine, there occurs a shortcoming in which the inner tub 7 is imbalanced due to the maldistribution of the laundry when the inner tub 7 is rotated at a high speed to spin-dry the laundry, thereby generating vibration and noise.
[0011] In the meantime, in the conventional vertical washing machine (in which a drive shaft is positioned perpendicular to the ground), there occur shortcomings in which the balancing force of the balancer cannot be adjusted due to its balancer being hermetically sealed, its balancer may be damaged due to its thermal expansion during the heating of washing water and, the manufacture and assembly of its balancer is difficult.
SUMMARY OF THE INVENTION
[0012] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a washing machine with a balancer, which is capable of improving the balancing capacity of its balancer to reduce vibration and noise, of preventing the balancer from being damaged due to thermal expansion to increase the durability of the balancer, and of simplifying the manufacture and assembly of the balancer to reduce the manufacturing cost of the washing machine.
[0013] In order to accomplish the above object, the present invention provides a washing machine, comprising an outer tub for accommodating washing water, an inner tub rotatably mounted in the outer tub for washing and spin-drying the laundry, a balancer mounted to the inner tub to be opened at its one side, the balancer accommodating water to balance the inner tub, water supply means for supplying washing water to the balancer, and a cabinet for constituting the boundary of the washing machine and enclosing the components of the washing machine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0015] [0015]FIG. 1 is a vertical cross section of a conventional washing machine;
[0016] [0016]FIG. 2 is a vertical cross section of a washing machine in accordance with the preferred embodiment of the present invention;
[0017] [0017]FIG. 3 is enlarged view of “A” portion of FIG. 2;
[0018] [0018]FIG. 4 is an enlarged, exploded perspective view showing the principal components of the washing machine;
[0019] [0019]FIG. 5 is a cross section of a balancer in accordance with the preferred embodiment of the present invention; and
[0020] [0020]FIG. 6 is a graph in which the displacements of an inner tub are plotted with regard to the rotational speeds of an inner tub.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Reference now should be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components.
[0022] With reference to FIGS. 2 to 6 , there is described a preferred embodiment of the present invention.
[0023] [0023]FIG. 2 is a vertical cross section of a washing machine in accordance with the preferred embodiment of the present invention. FIG. 3 is enlarged view of “A” portion of FIG. 2. FIG. 4 is an enlarged, exploded perspective view showing the principal components of the washing machine. FIG. 5 is a cross section of a balancer in accordance with the preferred embodiment of the present invention. FIG. 6 is a graph in which the displacements of an inner tub are plotted with regard to the rotational speeds of an inner tub.
[0024] As shown in FIG. 2, the washing machine of the present invention includes a cabinet 1 that constitutes the boundary of the washing machine. A door 3 is openably mounted to the front of the cabinet 1 to allow the laundry to be fed and discharged. An outer tub 5 is situated in the cabinet 1 to accommodate washing water. An inner tub 7 provided with a plurality of water passage holes 7 a is rotatably positioned in the outer tub 5 . A lifter 9 is mounted on the bottom of the interior of the inner tub 7 . A water supply means is mounted to the interior of the cabinet 1 to supply washing water to the washing machine. A motor 19 is attached beneath the outer tub 5 . A belt 21 and a pulley 23 are situated in the vicinity of the motor 19 to rotate the inner tub 7 normally and reversely.
[0025] A balancer 100 is mounted to the front end of the inner tub 7 to balance the inner tub 7 during high-speed rotation for a spin-drying process, thereby reducing vibration and noise. The balancer 100 may be attached to the front end of the inner tub 7 in a tight-fitting or welding fashion, or may be integrally formed with the inner tub 7 .
[0026] The balancer 100 comprises a cylindrical portion 101 extended horizontally, a bell portion 102 expanded downwardly rearward from the rear end of the cylindrical portion 101 , a skirt portion 103 extended from the rear end of the bell portion 102 to the rear end of the cylindrical portion 101 , and a bent portion 104 extended radially inward from the front end of the skirt portion 103 to be spaced apart from the cylindrical portion 101 and form an opening 105 between the cylindrical portion 101 and itself. Accordingly, a space is formed between the bell portion 102 , the skirt portion 103 and the bent portion 104 to accommodate water, and the cylindrical portion 101 is projected forward past the bent portion 104 .
[0027] As a result, as the balancer 100 is rotated, water having being supplied to the space 106 through the opening 105 is moved through the skirt portion 103 and fills the entire space 106 , due to centrifugal force.
[0028] A speed sensor 210 is mounted to a portion of the motor 19 to sense that the rotational speed of the inner tub 7 passes through a critical speed (see “C” in FIG. 6) of the inner tub 7 and reaches a speed (see “B” in FIG. 6) at which the centrifugal force exceeds gravitational force. The water supply means is comprised of a water supply source 200 , a water supply hose 230 for supplying water from the water supply source 200 to the space 106 of the balancer 100 through the opening 105 of the balancer 100 , and a water supply valve 220 mounted on the water supply hose 230 for selectively being opened and closed in response to a signal from the speed sensor 210 .
[0029] The critical speed denotes a speed in which the amplitude of vibration is infinitely enlarged due to the coincidence of the natural frequency of the inner tub and the rotational speed of a drive shaft during the rotation of the drive shaft along with the inner tub 7 .
[0030] Next there is described the operation of the washing machine with a balancer.
[0031] When a user starts the washing machine by manipulating a control panel (not shown) after opening the door 7 , feeding the laundry into the inner tub 7 and shutting the door 7 , the water supply valve 220 is turned ON, and water is initially supplied through the water supply hose 230 and sent to the space 106 of the balancer 100 through the opening 105 of the balancer 100 . At this time, water having filled the space of the balancer 100 overflows through the opening 105 of the balancer 100 into the outer tub 5 , and thereafter water having overflowed into the outer tub 5 passes through the water passage holes 7 a and fills the inner tub 7 .
[0032] When water fills the outer and inner tubs 5 and 7 to a predetermined height, the water pressure of the interior of the outer tub 5 is transmitted to the water level sensor 31 through the drain bellows 25 and a water level sensor hose 33 . As a result, the water supply valve 220 is turned OFF, thereby stopping a water supply process.
[0033] When the water supply is stopped, washing and rinsing processes are performed while the motor 19 is operated and the inner tub 7 is normally and reversely rotated by means of the belt 21 and the pulley 23 .
[0034] At this time, the laundry is raised up to a predetermined height by means of the lifter 9 and lowered down from the height by means of gravitational force, so that the laundry is washed through a mechanical operation.
[0035] After the washing and rinsing processes are performed, the drain valve 25 a is opened, washing water is drained through the drain bellows 25 , and the washing water having passed through the drain bellows 25 is pumped by the drain pump 27 and drained to the outside through the drain hose 29 .
[0036] Meanwhile, after the washing and rinsing processes are performed, the motor 19 is rotated in a predetermined direction to spin-dry the laundry and the inner tub 7 is also rotated in the direction, so that the laundry is spin-dried by means of centrifugal force. Water removed from the laundry is drained to the outside through the water passage holes 7 a of the inner tub 7 , the outer tub 5 , the drain bellows 25 , the drain pump 27 and the drain hose 29 .
[0037] When the speed sensor 210 mounted to a portion of the motor 19 senses that the rotational speed of the inner tub 7 passes through the critical speed of the inner tub 7 and reaches a speed at which the centrifugal force exceeds gravitational force, the water supply valve 220 is opened and water is supplied from the water supply source 200 through the water supply hose 230 . Water having been supplied through the water supply hose 230 is supplied to the space 106 through the opening 105 of the balancer 100 .
[0038] The water having entered the space 106 balances the inner tub 7 tending to lean while being brought into tight contact with and flowing along the inner surface of the skirt portion 103 of the balancer 100 by means of centrifugal force, thereby reducing vibration and noise.
[0039] The balancing capacity of the balancer 100 depends upon the amount of water supplied to the space 106 and the height H of the bent portion 104 .
[0040] In the meantime, in the case of utilizing boiled water, the balancer 100 is not damaged due to thermal expansion because the balancer 100 can absorb the effect of the thermal expansion due to the presence of the opening 105 .
[0041] Although the speed sensor 210 is described as being mounted to a portion of the motor 19 , the position of the speed sensor 210 is not limited to that position, but the speed sensor 210 may be mounted to a portion of the inner tub 7 to sense the rotational speed of the inner tub 7 .
[0042] In addition, although water is described as being supplied through the space 106 of the balancer 100 , the washing water can be supplied in other ways. That is, during washing and rinsing processes water may be supplied through a portion of the outer tub 5 as in a conventional art, while during a spin-drying process water may be supplied to the interior of the balancer 100 .
[0043] [0043]FIG. 6 is a graph in which the maximum displacements of the inner tub 7 with and without the balancer 100 are plotted with regard to the rotational speeds of the inner tub 7 . In the graph, an “X” axis represents the rotational speeds of the inner tub 7 during a spin-drying process, while a “Y” axis represents the maximum displacements of the inner tub 7 . The speed “B” denotes a speed that the inner tub 7 reaches after passing through the critical speed C and at which centrifugal force exceeds gravitational force.
[0044] In the graph, a dotted line represents the displacements of the inner tub 7 without the balancer 100 with regard to the maximum rotational speed of the inner tub 7 without the balancer 100 , while a solid line represents the displacements of the inner tub 7 with the balancer 100 with regard to the maximum rotational speed of the inner tub 7 with the balancer 100 . As apparent from the graph, in a case where the balancer 100 is mounted to the inner tub 7 the displacements of the inner tub 7 can be reduced.
[0045] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
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Disclosed herein is a washing machine with a balancer. This invention provides a washing machine with a balancer, which is capable of improving the balancing capacity of its balancer, preventing the balancer from being damaged due to thermal expansion, and simplifying the manufacture and assembly of the balancer. The washing machine includes an outer tub for accommodating washing water. An inner tub rotatably is mounted in the outer tub for washing and spin-drying the laundry. A balancer is mounted to the inner tub to be opened at its one side. The balancer accommodates water to balance the inner tub. Water supply means supplies washing water to the balancer. A cabinet constitutes the boundary of the washing machine and encloses the components of the washing machine.
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CROSS-REFERENCES TO RELATED APPLICATIONS
This application is related to copending application Ser. Nos. 626,843, entitled "Fluid Moderator Control System-D 2 O/H 2 O" by R. A. George, et al, filed July 2, 1986; 626,942, entitled "Fluid Moderator Control System Fuel Assembly Seal Connector" by L. Veronesi, et al, filed July 2, 1984; and 626,943, entitled "Fluid Moderator Control System-Reactor Internals Distribution System" by H. F. Fensterer, et al, filed July 2, 1984; all of which are assigned to the Westinghouse Electric Corporation.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to the field of pressurized water nuclear reactors and in particular to a fuel assembly for a pressurized water reactor employing a fluid moderator system for purposes of spectral shift control.
2. Description of the Prior Art
In typical pressurized water nuclear reactors, control over the fission process, or reactivity control is accomplished during reactor operation by varying the amount of neutron-absorbing materials within the core of the reactor. One method to effectuate reactivity control is by the use of control rods containing such neutron absorbing materials or poisons which are inserted within the reactor core. Control over the fission process may be accomplished by varying the number of control rods, the size of the control rods and their radial and axial locations within the core. Burnable poisons (by the fissioning process) and poisons dissolved in the reactor coolant can additionally be used for purposes of such control.
In order to lengthen the core life, it is typical, in conventionally designed commercial pressurized water reactors, to design in an excess of reactivity at reactor start-up. The excess reactivity is controlled as stated above, and is gradually depleted over the extended life of the core. Soluble boron, dissolved in the reactor coolant is most often used to control the initial excess reactivity. As the excess reactivity in the core is depleted during the reactor operation, the neutron absorbing boron is gradually removed so as to utilize the original excess reactivity to maintain the fission process. While this control arrangement provides an effective means of controlling a nuclear reactor over an extended core life, the neutron absorbing boron used during core life absorbs neutrons and removes reactivity from the reactor core that could otherwise be used in a more productive manner. For example, the reactivity could be used to convert fertile material to plutonium or to fissile uranium which even further extends the reactor core life by fissioning the then generated fissile material. Without such conversion, however, the consumption of reactivity is an inefficient depletion of uranium resulting in higher fuel costs than would otherwise result. In view of the above, it would be an obvious advantage to be able to extend the life of a core having an initial amount of excess reactivity while not suppressing the excess reactivity with neutron absorbing materials, but rather using the excess reactivity in a positive manner thereby providing an extended core life with a significantly lower overall fuel cost.
It is well known that fuel element enrichment can be reduced and the conversion ratio of producing fissile materials can be increased by employing a "hardened" (higher neutron energy) spectrum during the first part of the fuel cycle to reduce excessive reactivity and to increase the conversion of fertile material to fissile material; then employing a "softer" (lower energy) neutron spectrum during the latter part of the fuel cycle to increase reactivity and extend the core life by fissioning the previously generated fissile material. One such method utilizing the above is known as spectral shift control which provides a reactor with an extended core life while reducing the amount of neutron absorbing material in the reactor core. In this art, the reduction of the excess reactivity, and, therefore, the neutron absorbing material, is achieved by replacing a portion of the ordinary reactor water with heavy water.
The heavy water is a less effective moderator than the ordinary reactor coolant water. This retards the chain reaction by shifting the neutron spectrum to higher energies permitting the reactor to operate at full power with reduced neutron absorbing material. This shift to a hardened neutron spectrum causes more fertile U-238 or Th-232 to be converted to fissile Pu-239 or U-233, respectively, that may thereafter be consumed in the reactor core producing heat and further extending the core life. Thus, the shift to an initially hard spectrum results in more neutrons being consumed in a useful manner rather than being wasted by the use of poisons. As the fissile material is consumed, the heavy water is gradually replaced with ordinary reactor coolant water creating a softer neutron spectrum whereby the core reactivity is maintained at a proper level. At the end of core life, essentially all of the heavy water has been replaced by the ordinary reactor coolant water. Thus, the reactor can be controlled by control rods without the use of additional neutron absorbing material and without the use of excess reactivity at start-up, resulting in significant uranium fuel cost savings. The additional Pu-239 or U-233 production also reduces the U-235 enrichment requirements.
While the spectral shift control is well known in theory, there exists a need to carry the theory into effect. To date, no apparatus exists which effectively and practically implements such theory.
It is, therefore, a primary object of the present invention to provide a fuel assembly for a pressurized water nuclear reactor which includes means for varying the reactor coolant water volume over a fuel cycle by replacing a portion of the water with heavy water during the early stages of core life and then gradually reducing the amount of heavy water and replacing it with ordinary water as the core life decreases.
SUMMARY OF THE INVENTION
The present invention comprises a fuel assembly for a pressurized water nuclear reactor having the capability of varying the amount of deuterium oxide or heavy water within the fuel assembly, thereby allowing for varying the core light water volume over the life of the fuel elements. The fuel element assembly comprises a square array of parallel arranged fuel elements having a plurality of moderator control tubes (MCT) and rod control cluster (RCC) guide tubes interspersed among the fuel elements. The fuel elements, MCTs, and the RCC guide tubes are spaced and supported by a plurality of axially arranged grids. Top and bottom manifolds respectively positioned at the upper and lower fuel assembly nozzles are employed to direct the flow of heavy water into and out from the moderator control tubes. Seal connectors appropriately attached to the manifolds maintain the separation of heavy water and light water (H 2 O) within the reactor and permits the D 2 O and the H 2 O or D 2 O/H 2 O mixture to be circulated into and out of the core MCTs. Adaptor plates comprising structural elements are located at the top and bottom nozzle to structurally combine the various components within the fuel assembly. During the first part of a fuel cycle where there is excess reactivity, neutron moderation is decreased by replacing some of the light water in the core with the less effective moderator, heavy water. During the last part of the fuel cycle, the process is reversed and regular water is added to the core by diluting the heavy water with regular water. This process occurs within the fuel assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the invention, reference is had to the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a vertical, partially cross-sectioned view of one embodiment of the inventive fuel assembly;
FIG. 2 is a cross-sectional view taken along the line 2--2 of FIG. 1, not showing the grids;
FIG. 3 is a view of the top plate of the upper nozzle taken along the line 3--3 of FIG. 1, not showing the top nozzle springs;
FIG. 4 is a view of the upper adaptor plate taken along the line 4--4 of FIG. 1;
FIG. 5 is a view of the upper manifold taken along the line 5--5 of FIG. 1;
FIG. 6 is a view of the lower manifold taken along the line 6--6 of FIG. 1;
FIG. 7 is a view of the adaptor plate of the bottom nozzle taken along the line 7--7 of FIG. 1; and,
FIG. 8 is a cross-sectional view illustrating the connection of the control rod guide thimble to the top nozzle adaptor plate.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1 of the drawings, there is depicted therein one embodiment of the inventive fuel assembly generally designated by the numeral 10. A plurality of parallel arranged fuel elements 11 are held in place by upper and lower Inconel grids 12 and a plurality of intermediate Zircaloy grids 13. Grids 12 and 13 serve also to space and support twenty-one moderator control tubes 14, and four rod cluster control tubes or guide thimbles 15.
The cross-sectional arrangement of the above-noted components is shown in FIG. 2. Each fuel element 11 comprises elongated cylindrical metallic tubes containing nuclear fuel pellets and having both ends sealed by appropriately shaped end plugs. Such fuel elements are well known in the art. In the embodiment, shown in FIG. 2, fuel elements 11 are arranged in a substantially 20×20 square array with an equal pitch between adjacent fuel elements 11. One fuel element 11a may be used for purposes of instrumentation. Each moderator control tube 14, preferably made from Zircaloy, and each rod cluster control tube 15, also preferably made from Zircaloy, occupies the space of and displaces four fuel rods. Hence, there are a total of two hundred and ninety-nine fuel elements 11. The moderator control tubes 14 are arranged in a 5×5 array with an equal pitch between adjacent tubes. For purposes of clarity and understanding, the moderator control tubes 14 are marked with a cross within the circumference thereof while the rod cluster control tubes 15 are marked with double crosses, each offset by an angle of 45°. Since the rod cluster control tubes 15 also form a square array, they are adapted to receive a type of rod control cluster or control rod which is well known in the art.
As can be seen in FIG. 1, each moderator control tube 14 comprises an elongated hollow tube 17 having an upper end plug 18 and a lower end plug 19 fixedly attached thereto such as by welding. End plugs 18 and 19 have openings 20 and 21 therethrough for the flow of either heavy water or regular reactor coolant water, or a combination thereof.
A plan view of the upper manifold 22 is shown in FIG. 5, while a plan view of the lower manifold 23 is shown in FIG. 6. Each manifold 22 and 23 may comprise a Zircaloy casting. The lower end plug 19 of the MCTs 14 is threadingly connected to the lower manifold 23. The upper end plug 18 is flange seated into flanges 24 provided on the underside of the upper manifold 22. In addition, each end of each MCT is welded to its respective manifold for pressure sealing purposes. Guide thimbles 15 pass through and are not connected to either the upper 22 or the lower 23 manifold. This is clearly shown in FIGS. 5 and 6.
A pair of spring loaded connectors 25 and 26 are connected to lower manifold 23 in the manner indicated in FIG. 1. Seal connectors 25 and 26 may be similar to the one described in copending U.S. patent application Ser. No. 626,942, filed July 2, 1984 in the name of L. Veronesi, et al, entitled "Fluid Moderator Control System Fuel Assembly Seal Connector" and assigned to Westinghouse Electric Corporation. Seal connector 25 provides for the inlet of heavy water or a combination of heavy and regular water flowing through the MCTs 14. Seal connector 26 provides for the outlet flow from the one MCT 14 axially aligned therewith. Hence, seal connector 25 provides for the inlet flow for twenty MCTs. The flow communication channels 27 provided in the lower manifold correspond to such an inlet and outlet flow arrangement. Flow channels 27 do not communicate with seal connector 26. Flow channels 27 may be "gun drilled" horizontally through ribs 28 and then plug welded (not shown) at the entrance of the drilled holes to provide flow communication between the twenty MCTs. A vertical through hole is, of course, required in the lower side of lower manifold at each axial location of the seal connectors 25 and 26; while, blind holes drilled through the upper surface of the lower manifold are required at each of the remaining nineteen MCT locations. The lower manifold 23 is seated within cutouts 29 provided in the four sides of lower nozzle 30. The upper manifold (FIG. 5) is similarly seated within cutouts 31 provided in the four sides of the upper nozzle 32. It will thus be appreciated that the lower manifold 23, the MCTs 14, the fuel rods 11, the grids 12 and 13, and the upper manifold 22 comprise a subassembly which is captured between the lower nozzle 30 and the upper nozzle 32. Additionally, there are structural interconnections with the above-stated subassembly and the four guide thimbles 15 which will be more fully explained hereinafter.
The upper manifold 22, at one end of the fuel assembly provides flow communication between each of the twenty-one MCTs as shown in FIG. 5. Flow channels 36 may also be "gun drilled" horizontally through ribs 37 and then plug welded (not shown) at the entrance of the drilled holes. A vertical blind hole is provided in the lower side of the upper manifold 22 at each axial location of the twenty-one MCTs 14. Because of the sealed arrangement between the bottom manifold 23 at a second end of the fuel assembly, the upper manifold 22 at said one end of the fuel assembly, and the MCTs 14, heavy water or a combination of heavy water and regular water may be introduced through seal connector 25 which then flows through flow holes 27 in lower manifold 23, up through twenty MCTs 14, through flow holes 36 in upper manifold 22, and down through the remaining MCT colinearly aligned with seal connector 26 and out said second end of the fuel assembly through seal connector 26. Seal connectors 25 and 26 are adapted to be fitted to the lower core support plate (not shown) and to appropriate flow inlet and outlet channels provided therein.
A structural lower adaptor plate 34 may be integrally formed with lower nozzle 30. Similarly, a structural upper adaptor plate 35 may be integrally formed with the upper nozzle 32. Guide thimbles 15 are structurally connected to the upper 35 and lower 34 adaptor plates. Hence, the upper nozzle 32, the guide thimbles 15, the upper manifold 22, the MCTs 14, the fuel rods 11, the grids 12 and 13, the lower manifold 23, and the lower nozzle 30 together form the structural make-up of fuel assembly 10.
Guide thimbles 15 comprise an elongated hollow Zircaloy tube open at its upper end and fitted with a connector plug 38 at its lower end. Guide thimbles 15, as previously stated, are adapted to accept a rod control cluster which is not part of this invention. An internally threaded blind hole is provided in the lower end of plug 38 for purposes of connecting guide thimble 15 to the structural lower adaptor plate 34. Adaptor plate 34 is shown in cross section in FIG. 7 and may be made in the form of a cross beam latice. There are four main beam members 39 having a boss 40 at the intersections thereof. Boss 40 is drilled through to accept a screw or bolt 41 which passes therethrough from the underside thereof and is threadingly engaged with the connector end plug 38 of the guide thimble 15. Thus, the guide thimbles 15 are screw connected to the structural lower adaptor plate 34. In order to prevent twisting of the guide thimble 15 when screw 41 is torque tightened, a groove 42 may be machined in each boss which engages a key 42 provided on the connector plug 38. Screw 41 may be lock welded to boss 40 by a welded lock pin (not shown) which is well known in the art. The adaptor plate 34 also includes eight secondary beams 43 which in conjunction with the lower manifold provide for capture of a portion of the fuel rods 11. The upper adaptor plate 35 in conjunction with the upper manifold 25 provides for capture of the remainder of the fuel rods 11. In this manner, all of the fuel rods 11 are captured from either above or below.
The upper end of the guide thimbles 15 is structurally connected to the upper adaptor plate 35. This is shown in FIG. 8. A machined stainless steel sleeve 44 is positioned within a hole in the upper adaptor plate 35 through the underside thereof. A threaded lock ring 45 engages the upper end of sleeve 44 from the upper side of adaptor plate 35 and is threaded and lock welded (not shown) to the same to prevent the possibility of loosening or disengagement. A key 63 engaged with aligned slots 64 and 65 prevents twisting of sleeve 44 when lock ring 45 is torque tightened. Guide thimble 15 is bulge connected to grooves 46 machined within the inner diameter of sleeve 44. Sleeve 44 extends down from adaptor plate 35 and through upper grid 12. Sleeve 44 is permanently connected to grid 12 such as by brazing or welding.
The upper adaptor plate 35 is shown in FIG. 4. Like the lower adaptor plate 34 but at the opposite end thereof, it provides the main structural support of fuel assembly 10. It may be made in the form of a cross beam lattice having four main members 60 having bosses 48 at their intersections to which the guide thimbles 15 are fastened as previously explained. Members 61 are also main support beams. The secondary beams 49 provide additional structural support and in conjunction with the upper manifold 22 provide for upper fuel rod 11 capture. Main members 60 and 61 accept the guide pins 51 for the top nozzle springs 52 which may be helically wound. Guide pins 51 have a slot 50 provided in their lower end which fits over main members 60 and 61 and is welded thereto. Springs 52 extend within retainer sleeves 53 and are mounted around the periphery of the top nozzle 32. Springs 52 seat on the upper adaptor plate 35 and penetrate through holes 54 in the top plate 55 of upper nozzle 32 which are shown in FIG. 3. The inwardly extending flange 57 on the upper end of sleeve 53 in conjunction with retaining ring 56 which is fitted within a circumferential groove in the outer diameter of sleeve 53 provides for capture of the sleeve by top plate 55. The enclosure 58 of top nozzle 32 may be integrally connected to top plate 55 and adaptor plate 35 and as such, structurally connects these two members. Enclosure 58 also provides a plenum for reactor coolant flow exiting from the fuel assembly 10. Quarter circles 59 in each corner of enclosure 58 form a circular hole 61 at the intersection of four adjacent fuel assemblies 10 (see FIG. 3). Circular holes 61 are adapted to receive guide pins (not shown) mounted on the upper core plate to provide for lateral positioning of the upper end of the fuel assemblies 10.
Referring to FIG. 1, it is seen that grids 12 and 13 are positioned at various locations along the length of fuel assembly 10. The grids 12 and 13 serve to space fuel rods 11, moderator control tubes 14, and guide thimble tubes 15 at appropriate distances from each other and to allow the reactor coolant (water) to circulate in heat transfer relationship with fuel rods 11. A more detailed description of a similar grid may be found in U.S. Pat. Nos. 3,379,617 and 3,379,619, both issued in the name of H. N. Andrews, et al. Grids 12 may comprise a spring-dimple design while grids 13 may comprise an all dimple design. Each of the grids 12 and 13 have metal sleeves 47 attached such as by welding or brazing to the grids 12 and 13 at the location of the four guide thimbles 15 and the twenty-one moderator control tubes 14. Sleeves 47 are bulge attached 48 only to the guide thimbles 15 which is well known in the art. The moderator control tubes 14 pass through sleeves 47 but are not attached thereto; the sleeves only provide guidance and bearing surfaces for the MCTs 14.
In accordance with the above, the invention provides new, novel, and useful apparatus comprising a fuel assembly for use with a pressurized water nuclear reactor which allows for spectral shift control by providing means for varying the reactor coolant water volume over a fuel cycle by replacing a portion of the water with heavy water during the early stages of core life and then replacing it with ordinary water as the core life decreases.
While the invention has been described, disclosed, illustrated and shown in certain terms or certain embodiments or modifications which it has assumed in practice, the scope of the invention is not intended to be nor should it be deemed to be limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended.
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A fuel assembly for a pressurized water nuclear reactor incorporating fluid moderator spectral shift control means. During the first part of the fuel cycle when there is excess reactivity, neutron moderation may be decreased by replacing a portion of the water within the core with a less effective moderator such as heavy water. During the life of the fuel, the heavy water is gradually replaced with regular water. The fuel assembly incorporates the necessary means and apparatus to effectuate such control.
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[0001] This application claim the benefit of U.S. Provisional Application No. 60/392673 filed Jun. 27, 2002.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention pertains to flapper valves, and particularly to flapper valves used for well completions.
[0004] 2. Related Art
[0005] Flapper valves are often used in subsurface safety valves. Subsurface safety valves are used in wells to contain wellbore fluids, particularly in the event of emergency situations in which there is potential danger to personnel, equipment, or the environment.
SUMMARY OF THE INVENTION
[0006] The present invention improves flapper valves by providing a curved flapper and a seat, the flapper and seat each having complementary undulating and tapered perimeters, with sealing surfaces designed to maintain seal integrity under higher pressure, for a given outer diameter to inner diameter ratio, compared to prior art flapper valves.
DESCRIPTION OF FIGURES
[0007] [0007]FIG. 1 is a perspective drawing of a flapper valve subassembly constructed in accordance with the present invention.
[0008] [0008]FIG. 2A is a schematic drawing of prior art showing one orientation of sealing surfaces relative to externally applied pressure.
[0009] [0009]FIG. 2B is a schematic drawing of prior art showing another orientation of sealing surfaces relative to externally applied pressure.
[0010] [0010]FIG. 2C is a schematic drawing showing an orientation of sealing surfaces relative to externally applied pressure in accordance with the present invention.
[0011] [0011]FIG. 3 is a perspective drawing of a flapper valve constructed in accordance with the present invention.
[0012] [0012]FIG. 4 is a perspective drawing of a flapper valve subassembly constructed in accordance with the present invention.
[0013] [0013]FIG. 5 is a perspective drawing showing a flapper valve constructed in accordance with this invention as an integral part of a completion assembly.
DETAILED DESCRIPTION
[0014] [0014]FIGS. 1 and 3 show one embodiment of a flapper valve 10 . In this embodiment, flapper valve 10 comprises a housing 12 , a flapper 14 , and a seat 16 . Housing 12 has a bore 18 providing a longitudinal passageway therethrough. Flapper valve 10 is generally installed some desired distance below ground as part of a tubing string (FIG. 5) used to convey fluids between a wellbore and the earth's surface. Bore 18 is in fluid communication with the tubing's interior passageway such that the fluids entering one end of the tubing must pass through bore 18 before exiting the opposite end of the tubing.
[0015] Flapper 14 , in the embodiment of FIG. 1, is a curved member having a high pressure surface 20 and a low pressure surface 22 . The terms “high” and “low” are meant to connote the pressure differential across flapper 14 when flapper 14 is in a closed state, blocking fluid flow from the wellbore to the surface. Flapper 14 has a hinge 24 by which it rotatably mounts to housing 12 . Hinge 24 allows flapper 14 to rotate between an open state and the closed state. Flapper 14 also has an orienting finger 26 extending radially outward opposite hinge 24 . High pressure surface 20 is curved to conform with the tubing curvature when flapper 14 is in the open state.
[0016] Extending between high pressure surface 20 and low pressure surface 22 is a transitional sealing surface 28 . Sealing surface 28 can taper radially inward or outward from high pressure surface 20 to low pressure surface 22 . In certain embodiments, such as in FIGS. 1, 3 and 4 , the taper angle can vary along the perimeter of flapper 14 . Flapper 14 has an undulating perimeter.
[0017] Seat 16 extends from within housing 12 such that it aligns and mates with flapper 14 when flapper 14 is in the closed state. Seat 16 has a mating sealing surface 30 that conforms to the slope of sealing surface 28 everywhere along sealing surface 30 . Seat 16 has an undulating perimeter to conform with that of flapper 14 . Thus, seat 16 has crests 32 and valleys 34 .
[0018] In operation, flapper valve 10 is usually set in either the open or the closed state. When flapper valve 10 is set in the open state, flapper 14 lays adjacent an inner wall of the tubing. Because the curvature of high pressure surface 20 matches the curvature of the tubing, bore 18 is largely unobstructed by flapper 14 . This is particularly true when flapper 14 is held against the tubing by a flow tube (not shown), as is well understood in the art.
[0019] When flapper valve 10 is set in the closed state, normally by moving the flow tube and allowing a biasing spring (not shown) to act on flapper 14 (all of which is well understood in the art), flapper 14 is rotated to contact seat 16 , sealing flapper valve 10 along sealing surfaces 28 , 30 and effectively blocking flow through bore 18 . Orienting finger 26 engages a slot 31 (FIG. 3) in housing 12 to help align flapper 14 onto seat 16 .
[0020] In the closed state, pressure from wellbore fluids act on flapper 14 and seat 16 . In certain flapper valves 10 , flapper 14 may have greater structural strength than seat 16 . In other flapper valves 10 , seat 16 may have greater structural strength than flapper 14 . In still other flapper valves 10 , flapper 14 and seat 16 may have comparable structural strengths.
[0021] For those cases in which seat 16 is relatively weak with respect to the flapper, the pressure has the most effect near crests 32 of seat 16 , inducing them to deflect radially inward. As used herein, the term “collapse force” refers to the force applied to seat 16 or flapper 14 causing the relevant component to move radially inward. The pressure also applies a net force on flapper 14 , driving flapper 14 into seat 16 . Tapered sealing surfaces 28 , 30 react against each other. If sealing surface 30 slopes radially inward, as shown in FIG. 2C, the net force applied to flapper 14 by the wellbore fluids is transferred across sealing surfaces 28 , 30 such that there is a radially outward component applied to seat 16 by flapper 14 . Thus, flapper 14 opposes the radially inward deflection of the crests 32 of seat 16 . That keeps sealing surfaces 28 , 30 properly aligned and mated to maintain an effective seal.
[0022] For those cases in which flapper 14 is relatively weak with respect to the seat, the pressure has the most effect on the portions of flapper 14 near valleys 34 of seat 16 , inducing flapper 14 to deflect radially inward. As before, the pressure also applies a net force on flapper 14 , driving flapper 14 into seat 16 . Tapered sealing surfaces 28 , 30 react against each other. If sealing surface 30 slopes radially outward, as shown in FIG. 4 in the vicinity of valleys 34 , the radially inward force applied to flapper 14 by the wellbore fluids is opposed by seat 16 . Thus, seat 16 opposes the radially inward deflection of flapper 14 in the vicinity of valleys 34 of seat 16 . That keeps sealing surfaces 28 , 30 properly aligned and mated to maintain an effective seal.
[0023] Similarly, the pressure may also tend to deflect flapper 14 radially inward near crests 32 of seat 16 . Thus, in some embodiments, it may be desirable for seat 16 to have an outward taper at crests 32 so seat 16 can support flapper 14 at crests 32 .
[0024] For those cases in which flapper 14 and seat 16 are of comparable structural strength, the pressure has the most effect near crests 32 of seat 16 , inducing them to deflect radially inward, and on those portions of flapper 14 near valleys 34 of seat 16 , inducing flapper 14 to deflect radially inward. The pressure also applies a net force on flapper 14 , driving flapper 14 into seat 16 . Tapered sealing surfaces 28 , 30 react against each other and flapper 14 and seat 16 reciprocally support each other against the pressure. Specifically, if sealing surface 30 slopes radially inward in the vicinity of crests 32 and radially outward in the vicinity of valleys 34 , seat 16 in the vicinity of crests 32 is supported by flapper 14 and flapper 14 in the vicinity of valleys 34 is supported by seat 16 . That keeps sealing surfaces 28 , 30 properly aligned and mated to maintain an effective seal.
[0025] Note that in some embodiments the flapper may be relatively weaker in some portions of the circumference and the seat in other portions. Other factors may also affect the taper of the sealing surfaces. Accordingly, many other embodiments are possible. For example, in one embodiment, the seat supports one portion of the flapper (e.g., a portion that is especially sensitive to radial deflection). In another example, the seat supports the flapper in one portion of the circumference and the flapper supports the seat in another portion.
[0026] In FIGS. 2A, 2B, and 2 C, the arrows represent the pressure applied by wellbore fluids. In FIG. 2C, the sealing surfaces taper radially inward from the high pressure side of the flapper to the low pressure side. Thus, the flapper and seat reciprocally oppose deformation by the other.
[0027] [0027]FIG. 2B shows a neutral flapper/seat orientation. In this case, the forces transferred between the elements are all in the longitudinal direction. Thus, no lateral support is provided between the elements, for example at the crests of typical flapper valves.
[0028] In FIG. 2A, the sealing surfaces taper radially outward from the high pressure side of the flapper to the low pressure side. Thus, the force from the flapper tends to further deform the seat in the same direction as the pressure, contributing to the seat's collapse in the case of a relatively weak seat 16 .
[0029] [0029]FIG. 4 shows an embodiment of a flapper valve subassembly in which flapper 14 and seat 16 have sealing surfaces 28 , 30 designed to mutually and reciprocally support each other against collapse forces applied by wellbore fluids onto the flapper 14 and seat 16 . The taper angle can vary from an outward angle, meaning the taper extends radially outward from the high pressure surface 20 to the low pressure surface 22 at valleys 34 , to an inward angle, meaning the taper extends radially inward from the high pressure surface 20 to the low pressure surface 22 at the crests 32 . In other embodiments, the taper angle may vary from an inward angle at valleys 34 to an outward angle at crests 32 . These angles are illustrated in FIGS. 2A and 2C. FIG. 2C shows an inward angle “A” measured form a horizontal or radial reference. FIG. 2A shows an outward angle “B”, also measured from a horizontal or radial reference.
[0030] Depending on the relative strengths of materials and other design characteristics, some embodiments have shown beneficial results if the taper angle at crest 32 varies between an outward angle of five degrees to an inward angle of sixty degrees, and the taper angle at valley 34 varies between an outward angle of thirty degrees to an inward angle of sixty degrees. The taper angles of each embodiment are selected in light of the preceding discussion.
[0031] The flapper and seat can be formed using a wire electrical discharge machining process, a ram or plunge electrical discharge machining process, by milling, or by a combination of those techniques.
[0032] Although only a few example embodiments of the present invention are described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. It is the express intention of the applicant not to invoke 35 U.S.C. §112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words ‘means for’ together with an associated function.
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A flapper valve having a curved flapper and a seat, the flapper and seat each having complementary undulating and tapered perimeters, with sealing surfaces designed to maintain seal integrity under higher pressure, for a given outer diameter to inner diameter ratio, compared to prior art flapper valves.
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[0001] This application is a continuation of U.S. Ser. No. 09/488,429 entitled “Modified Polysaccharides Containing Amphiphilic Hydrocarbon Moieties” filed on Jan. 20, 2000, which application claims priority from U.S. Serial No. 60/117,085 entitled “Modified Polysaccharides Containing Amphiphilic Hydrocarbon Moieties” filed on Jan. 25, 1999, now abandoned. The entirety of U.S. Ser. No. 09/488,429 is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] In the manufacture of paper products, such as facial tissue, bath tissue, paper towels, dinner napkins and the like, a wide variety of product properties are imparted to the final product through the use of chemical additives. Examples of such additives include softeners, debonders, wet strength agents, dry strength agents, sizing agents, opacifiers and the like. In many instances, more than one chemical additive is added to the product at some point in the manufacturing process. Unfortunately, there are instances where certain chemical additives may not be compatible with each other or may be detrimental to the efficiency of the papermaking process, such as can be the case with the effect of wet end chemicals on the downstream efficiency of creping adhesives. Another limitation, which is associated with wet end chemical addition, is the limited availability of adequate bonding sites on the papermaking fibers to which the chemicals can attach themselves. Under such circumstances, more than one chemical functionality compete for the limited available bonding sites, oftentimes resulting in the insufficient retention of one or both chemicals on the fibers.
[0003] Therefore, there is a need for a means of applying more than one chemical functionality to a paper web which mitigates the limitations created by limited number of bonding sites.
SUMMARY OF THE INVENTION
[0004] In certain instances, two or more chemical functionalities can be combined into a single molecule, such that the combined molecule imparts at least two distinct product properties to the final paper product that heretofore have been imparted through the use of two or more different molecules. More specifically, modified polysaccharides (such as starches, gums, chitosans, celluloses, alginates, sugars, etc.), which are commonly used in the paper industry as strengthening agents, surface sizes, coating binders, emulsifiers and adhesives, can be combined into a single molecule with amphiphilic hydrocarbons (e.g. surface active agents) which are commonly utilized in the paper industry to control absorbency, improve softness, enhance surface feel and function as dispersants. The resulting molecule is a modified polysaccharide having surface active moieties which can provide several potential benefits, depending on the specific combination employed, including: (a) strength aids that do not impart stiffness; (b) softeners that do not reduce strength; (c) wet strength with improved wet/dry strength ratio; (d) debonders with reduced Tinting and sloughing; (e) strength aids with controlled absorbency; and (f) surface sizing agents with improved tactile properties.
[0005] Hence in one aspect, the invention resides in a modified polysaccharide containing one or more amphiphilic hydrocarbon moieties, said modified polysaccharide having the following structure:
Polysac—Z 3 R 1
or
—Polysac—Z 3 R 1 —Polysac—
[0006] where
[0007] Polysac=any polysaccharide, monosaccharide, or sugar residue, modified or unmodified;
[0008] Z 3 =—CH 2 , —COO—, —OOC—, —CONH—, —NHCO—, —O—, —S—, —OSO 2 O—, —OCOO—, —NHCOO—, —OOCNH, —NHCONH—, —CONCO—, or any other radical capable of bridging the R 1 group to the polysaccharide backbone portion of the molecule; and
[0009] R 1 =any organofunctional group with the only limitation being that R 1 must contain a moiety consisting of an amphiphilic hydrocarbon, normal or branched, saturated or unsaturated, substituted or unsubstituted, with or without esterification, with or without etherification, with our without sulfonation, with or without hydroxylation, with or without ethoxylation or propoxylation, and having a carbon chain length of 4 or greater.
[0010] In another aspect, the invention resides in a paper sheet, such as a tissue or towel sheet, comprising a modified polysaccharide containing one or more amphiphilic hydrocarbon moieties, said modified polysaccharide having the following structure:
Polysac—Z 3 R 1
or
—Polysac—Z 3 R 1 —Polysac—
[0011] where
[0012] Polysac=any polysaccharide, monosaccharide, or sugar residue, modified or unmodified;
[0013] Z 3 ═—CH 2 , —COO—, —OOC—, —CONH—, —NHCO—, —O—, —S—, —OSO 2 O—, —OCOO—, —NHCOO—, —OOCNH, —NHCONH—, —CONCO—, or any other radical capable of bridging the R 1 group to the polysaccharide backbone portion of the molecule; and
[0014] R 1 =any organofunctional group with the only limitation being that R 1 must contain a moiety consisting of an amphiphilic hydrocarbon, normal or branched, saturated or unsaturated, substituted or unsubstituted, with or without esterification, with or without etherification, with our without sulfonation, with or without hydroxylation, with or without ethoxylation or propoxylation, and having a carbon chain length of 4 or greater.
[0015] In another aspect, the invention resides in a method of making a paper sheet, such as a tissue or towel sheet, comprising the steps of: (a) forming an aqueous suspension of papermaking fibers; (b) depositing the aqueous suspension of papermaking fibers onto a forming fabric to form a web; and (c) dewatering and drying the web to form a paper sheet, wherein a modified polysaccharide is added to the aqueous suspension, said modified polysaccharide having the following structure:
Polysac—Z 3 R 1
or
—Polysac—Z 3 R 1 —Polysac—
[0016] where
[0017] Polysac=any polysaccharide, monosaccharide, or sugar residue, modified or unmodified;
[0018] Z 3 ═—CH 2 , —COO—, —OOC—, —CONH—, —NHCO—, —O—, —S—, —OSO 2 O—, —OCOO—, —NHCOO—, —OOCNH, —NHCONH—, —CONCO—, or any other radical capable of bridging the R 1 group to the polysaccharide backbone portion of the molecule; and
[0019] R 1 =any organofunctional group with the only limitation being that R 1 must contain a moiety consisting of an amphiphilic hydrocarbon, normal or branched, saturated or unsaturated, substituted or unsubstituted, with or without esterification, with or without etherification, with our without sulfonation, with or without hydroxylation, with or without ethoxylation or propoxylation, and having a carbon chain length of 4 or greater.
[0020] The amount of the modified polysaccharide added to the fibers can be from about 0.02 to about 2 weight percent, on a dry fiber basis, more specifically from about 0.05 to about 1 weight percent, and still more specifically from about 0.1 to about 0.75 weight percent. The modified polysaccharide can be added to the fibers at any point in the papermaking process. A preferred addition point is where the fibers are suspended in water. However, modified polysaccharides can also be added topically to a dried paper web.
[0021] As used herein, polvsaccharides are carbohydrates that can be hydrolyzed to many monosaccharides and include, but are not limited to, starches (primarily modified starches from potato, corn, waxy maize, tapioca and wheat) which can be unmodified, acid modified, enzyme modified, cationic, anionic or amphoteric; carboxymethylcellulose, modified or unmodified; natural gums, modified or unmodified (such as from locust bean and guar); sugars, modified or unmodified; chitosan, modified or unmodified; and dextrins, modified and unmodified.
[0022] “Monosaccharide” is a carbohydrate that cannot be hydrolyzed into simpler compounds.
[0023] “Carbohydrates” are polyhydroxy aldehydes, polyhydroxy ketones or compounds that can be hydrolyzed to them.
[0024] As used herein, amphiphilic hydrocarbon moieties are organic compounds including alkanes, alkenes, alkynes and cyclic aliphatics which contain surface active agents. The amphiphilic hydrocarbons can be linear or branched, saturated or unsaturated, substituted or unsubstituted.
[0025] Methods of making paper products which can benefit from the various aspects of this invention are well known to those skilled in the papermaking art. Exemplary patents include U.S. Pat. No. 5,785,813 issued Jul. 28, 1998 to Smith et al. entitled “Method of Treating a Papermaking Furnish For Making Soft Tissue”; U.S. Pat. No. 5,772,845 issued Jun. 30, 1998 to Farrington, Jr. et al. entitled “Soft Tissue”; U.S. Pat. No. 5,746,887 issued May 5, 1998 to Wendt et al. entitled “Method of Making Soft Tissue Products”; and U.S. Pat. No. 5,591,306 issued Jan. 7, 1997 to Kaun entitled “Method For Making Soft Tissue Using Cationic Silicones”, all of which are hereby incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWING
[0026] [0026]FIG. 1 shows a macroscopic structure of amphiphilic moieties attached in pendant fashion to a polysaccharide.
[0027] [0027]FIG. 2 shows a macroscopic structure of amphiphilic moieties attached in series to a polysaccharide molecule.
DETAILED DESCRIPTION OF THE INVENTION
[0028] To further describe the invention, examples of the synthesis of some of the various chemical species are given below.
Polysaccharides
[0029] Starches
[0030] Unmodified starch has the structure as shown below. Unmodified starches can differ in properties such as amylopectin: amylose ratio, granule dimension, gelatinization temperature, and molecular weight. Unmodified starches have very little affinity for fibers, and modifications are widely done to extend the number of wet end starch additives available for use. Modifications to starches generally fall under one of the following categories: 1) Physical modifications, 2) Fractionation into amylose and amylopectin components, 3) Thermomechanical conversion, 4) Acid hydrolysis, 5) Chemical modifications, 6) Oxidation, 7) Derivatization and 8) Enzyme conversion.
[0031] Starch derivatives are the most common type of dry strength additive used in the paper industry. The 1990 edition of the TAPPI publication “Commercially Available Chemical Agents for Paper and Paperboard Manufacture” lists 27 different starch dry strength products. Starch chemistry primarily centers on reactions with the hydroxyl groups and the glucosidic (C—O—C) linkages. Hydroxyl groups being subject to standard substitution reactions and the glucosidic linkages being subject to cleavage. In theory the primary alcohol at the C-6 position should be more reactive than the secondary alcohols at the C-2 and C-3 positions. Also, it has been found that the tuber starches are more reactive than the cereal starches.
[0032] A large variety of starch esters and ethers have been described. Few have been actively marketed due to non-specific properties resulting from the substitution groups. Esters will generally be prepared via reaction of the acid chloride or anhydride with the starch. Hydrophobic type structures can be introduced with this functionalization and such structures have found applications in the paper industry as adhesives, and grease resistant paper size coatings. (Starch Conversion Technology, 1985)
[0033] Cationic starches are recognized as the choice for wet end additives due to their substantivity with cellulose fibers. The cationization of starches is accomplished by reaction with various tertiary and quaternary amine reagents. In general, a reactive chloride or epoxy group on one end of the reagent reacts with a starch hydroxyl group. The cationic portion of the amine then ionizes in the presence of water to form the positively charged derivative which is substantive to fiber. Quaternary ammonium derivatives are most commonly used in the paper.
[0034] Other ionic charged starches are produced by reaction of starch with amino, imino, ammonium, sulfonium, or phosphonium groups, all of which carry an ionic charge. The key factor in their usefulness is their affinity for negatively charged substrates such as cellulose. These ionic starches have found widespread use in the paper industry as wet end additives, surface sizing agents and coating binders. Cationic starches improve sheet strength by promoting ionic bonding and additional hydrogen bonding within the cellulose fibers. Some common reagents used to prepare cationic starches include: 2-diethylaminoethyl chloride (DEC); 2-dimethylaminoethyl chloride; 2-diisopropylaminoethyl chloride; 2-diethylaminoethyl bromide; 2-dimethylaminoisopropyl chloride; N-alkyl-N-(2-haloethyl)-aminomethylphosphonic acids; and 2,3-epoxypropyltrimethylammonium chloride.
[0035] Epichlorohydrin reacts with tertiary amines or their salts in water or nonaqueous solvents to form the quaternary ammonium reagents. Trimethylamine, dimethylbenzyl amine, triethylamine, N-ethyl and N-methyl morpholine, dimethylcyclohexylamine, and dimethyldodecylamine (Paschall, E.F., U.S. Pat. No. 2,876,217, 1959 and U.S. Pat. No. 2,995,513, 1961) have been used.
[0036] Cyanamide and dialkyl cyanamides can be used to attach imino carbamate groups on starches. These groups show cationic activity upon treatment with acids. The acidified products are stable to hydrolysis. Cationic cyanamide starches show useful properties as textile sizes and dry strength additives in paper. (Chamberlain, R. J., U.S. Pat. No. 3,438,970, 1969)
[0037] Aminoethylated starches are produced by treatment of ethyleneimine with starch in organic solvents or dry. Acidified products are useful as wet end paper additives (Hamerstrand, et al, “An evaluation of cationic aminoethyl cereal flours as wet end paper additives” Tappi, 58,112, 1975). Starches react with isatoic anhydride and its derivatives to form anthranilate esters with primary or secondary amino groups (U.S. Pat. No., 3,449,886; 3,511,830; 3,513,156; 3,620,913). Products with primary amino anthranilate groups can be derivatized and used to improve wet rub resistance in paper coatings.
[0038] Cationic starches containing anionic xanthate groups provided both wet strength and dry strength to paper when used as wet end additives in unbleached kraft pulp systems. (Powers, et al, U.S. Pat. No. #3,649,624, 1972). In this system it is believed that the permanent wet strength results from covalent bonding from the xanthate side chain reactions. (Cheng, W.C., et al, Die Starke, 30, 280,1978)
[0039] Cationic dialdehyde starches are useful wet end additives for providing temporary wet strength to paper. They are produced by periodic acid oxidation of tertiary amino or quaternary ammonium starches, by treating dialdehyde starch with hydrazine or hydrazide compounds containing tertiary amino or quaternary ammonium groups, and several other reactions.
[0040] Graft copolymers of starch are widely known. Some graft copolymers made with starches include: vinyl alcohol; vinyl acetate; methyl methacrylate; acrylonitrile; styrene; acrylamide; acrylic acid; methacrylic acid; and cationic monomers with amino substituents including: 2-hydroxy-3-methacrylopropyltrimethylammonium chloride (HMAC); N,N-dimethylaminoethyl methacrylate, nitric acid salt (DMAEMA*HNO 3 ); N-t-butylaminoethyl methacrylate, nitric acid salt (TBAEMA*HNO 3 ); andN, N,N-trimethylaminoethyl methacrylate methyl sulfate (TMAEMA*MS).
[0041] Polyacrylonitrile (PAN)/starch graft copolymers are well known in the art. Treatment of the PAN/starch graft copolymers with NaOH or KOH converts the nitrile substituents to a mixture of carboxamide and alkali metal carboxylate. Such hydrolyzed starch-g-PAN polymers (HSPAN) are used as thickening agents and as water absorbents. Important applications for HSPAN include use in disposable soft goods designed to absorb bodily fluids. (Lindsay, W. F., Absorbent Starch Based Copolymers—Their Characteristics and Applications, Formed Fabrics Industry, 8(5), 20, 1977).
[0042] Copolymers with water-soluble grafts are also well known. Many of the water soluble graft copolymers are used for flocculation and flotation of suspended solids in the paper, mining, oil drilling and other industries. (Burr, R. C., et al, “Starch Graft Copolymers for Water Treatment”, Die Starke, 27, 155, 1975). Graft copolymers from the cationic amine containing monomers are effective retention aids in the manufacture of filled papers. Starch-g-poly(acrylamide-co-TMAEMA*MS) was found to improve drainage rates while increasing dry tensile strength of unfilled paper handsheets. (Heath, H. D., et al, “Flocculating agent-starch blends for interfiber bonding and filler retention, comparative performance with cationic starches”, TAPPI, 57(11), 109, 1974.)
[0043] Thermoplastic-g-starch materials are also known, primarily with acrylate esters, methacrylate esters and styrene. Primary interest for these materials is in preparation of biodegradable plastics. No use of these materials as a paper additive has been found.
[0044] Other miscellaneous graft copolymers are known. Saponified starch-g-poly(vinyl acetate) has been patented as a sizing agent for cotton, rayon and polyester yarns. (Prokofeva, et al, Russian patent 451731,1975). Graft copolymers have been saponified to convert starch-g-poly(vinyl acetate) copolymers into starch-g-poly(vinyl acetate) copolymers. As with the thermoplastic-g-starch copolymers most of these materials have been evaluated as polymeric materials in their own right and not as additives for paper.
[0045] Carboxymethyl cellulose, methylcellulose, alginate, and animal glues are superior film formers. These materials are typically applied via surface application and not added in the wet end of the process to improve dry strength. The products are relatively expensive and although they can be used alone they are typically employed in conjunction with starches or other materials.
[0046] Gums:
[0047] Gums and mucilages use in papermaking dates back to ancient China. These mucilages were obtained from various plant roots and stems and were used primarily as deflocculating and suspending agents for the long fibered pulps. As papermaking evolved other advantages of using these materials became obvious including the ability of these materials to hold the wet fiber mat together during the drying process. As papermaking evolved to using shorter and shorter fibers these gums found increased use as a means of obtaining paper strength. Since World War II the use of gums in papermaking has increased substantially.
[0048] Water soluble, polysaccharide gums are highly hydrophilic polymers having chemical structures similar to cellulose. The main chain consists of β-1,4 linked mannose sugar units with occurrence of α-1,6 linked galactose side chains. Their similarity to cellulose means they are capable of extensive hydrogen bonding with fiber surfaces. Further enhancement of dry strength occurs due to the linear nature of the molecules.
[0049] They are vegetable gums and include as examples 1) locust bean gum, 2) guar gum, 3) tamarind gum, and 4) karaya, okra and others. Locust bean gum and guar gum are the most commonly used. They have been used in the paper industry since just prior to WWII. Since the natural materials are non-ionic they are not retained on fibers to any great extent. All successful commercial products have cationic groups attached to the main chain which increases the retention of the gums on the fiber surfaces. Typical addition rates for these materials are on the order of 0.1-0.35%.
[0050] The dry strength improvement of paper furnishes through use of polysaccharide gums is derived from the linear nature of the polymer and through hydrogen bonding of the hydroxyl hydrogen of the polymer with similar functional groups on the surface of the cellulosic fibers.
[0051] The most effective gums are quaternary ammonium chloride derivatives containing a cationic charge. The cationic functionality will help the gum retain better to the fibers as well as reducing the usually higher negative zeta potential of the paper furnish, especially when fillers and fines are present in the white water. This change in zeta potential leads to a more thorough agglomeration of the fines in the system by forming more cohesive flocs. These in turn are trapped by longer fibers filling the voids among the larger fibers with additional material that helps in the inter fiber bonding of the wet web, which in turn leads to dry strength improvement.
[0052] Although a variety of guar gum derivatives have been prepared, there are only three dervivatizations which have achieved commercial significance. These are 1) Quaternization, 2) Carboxymethylation and 3) Hydroxypropylation. The structure of guar gum and derivatives is shown below.
[0053] Chitosan:
[0054] Chitosan is a high molecular weight linear carbohydrate composed of β-1,4-linked 2-amino-2-deoxy-D-glucose units. It is prepared from the hydrolysis of the N-acetyl derivative called chitin. Chitin is isolated in commercial quantities from the shells of crustaceans. Chitin is insoluble in most common solvents, however, chitosan is soluble in acidified water due to the presence of basic amino groups. Depending on the source and degree of deacetylation chitosans can vary in molecular weight and in free amine content. In sufficiently acidic environments the amino groups become protonated and chitosan behaves as a cationic polyelectrolyte. It has been reported that chitosans increase the dry strength of paper more effectively than other common papermaking additives including the polyethylenimines and polyacrylamides.
[0055] Chitosan and starch are both polymers of D-glucose but differ in two aspects. First, chitosan has an amino group on each glucose unit and therefore has a stronger cationic character than cationic starch. Secondly, starch differs in its molecular configuration. Starch contains amylopectin which has a three dimensional molecular structure and amylose, which has linear macromolecules. The glucose molecules of starch have an α-configuration which gives the molecules a helical form. Chitosan resembles cellulose and xylans in that it has β-linked D-monosaccharide units and tends to have straight molecular chains. The functionally reactive groups of a straight polymer molecule are more easily accessible than those of a branched, random configuration molecule and are expected to interact more effectively with the polar groups on cellulose. The structure of chitosan is shown below.
[0056] Sugars
[0057] Also included in the saccharides are the simple sugars. These include the hexoses shown below. These compounds actually exist in the cyclic acetal form as shown below for glucose. Derivatives of these sugars are included within this definition.
[0058] Such derivatives include but are not limited to things such as gluconic acid, mucic acid, mannitol, sorbitol, etc. The derivatives generally do not exist in cyclic form.
[0059] Amphiphilic Hydrocarbon Moieties
[0060] Amphiphilic hydrocarbon moieties are a group of surface active agents (surfactants) capable of modifying the interface between phases. Surfactants are widely used by the industry for cleaning (detergency), solubilizing, dispersing, suspending, emulsifying, wetting and foam control. In the papermaking industry, they are often used for deinking, dispersing and foam control. They have an amphiphilic molecular structure: containing at least one hydrophilic (polar) region and at least one lipophilic (non-polar, hydrophobic) region within the same molecule. When placed in a given interface, the hydrophilic end leans toward the polar phase while the lipophilic end orients itself toward the non polar phase.
[0061] The hydrophilic end can be added to a hydrophobe synthetically to create the amphiphilic molecular structure. The following is a schematic pathway for making a variety of surfactants:
[0062] Based on the charge, surfactants can be grouped as amphoteric, anionic, cationic and nonionic.
[0063] First with regard to the amphoteric surfactants, the charges on the hydrophilic end change with the environmental pH: positive in acidic pH, negative at high pH and become zwitterions at the imtermediate pH. Surfactants included in this category include alkylamido alkyl amines and alkyl substituted amino acids.
[0064] Structure commonly shared by alkylamido alkyl amines:
[0065] where
[0066] R 0 =a C 4 or higher alkyl or aliphatic hydrocarbon, normal or branched, saturated or unsaturated, substituted or unsubstituted.
[0067] n≧2
[0068] R 1 =hydroxy or carboxy ended alkyl or hydroxyalkyl groups, C chain≧2C, with or without ethoxylation, propoxylation or other substitution.
[0069] Z=H or other cationic counterion.
[0070] Structure shared commonly by alkyl substituted amino acids:
R 1 —NR′ 2 Z
[0071] where
[0072] R 1 =alkyl or aliphatic hydrocarbon, normal or branched, saturated or unsaturated, substituted or unsubstituted, C chain≧4C,
[0073] ≧2,
[0074] Z=H or other cationic counterion
[0075] R′=carboxylic end of the amino acid.
[0076] With regard to the anionics, the hydrophilic end of the surfactant molecule is negatively charge. Anionics consist of five major chemical structures: acylated amino acids/acyl peptides, carboxylic acids and salts, sulfonic acid derivatives, sulfuric acid derivatives and phosphoric acid derivatives.
[0077] Structure commonly shared by acylated amino acids and acyl peptides:
R 0 OCO—R 1 —COOZ
or
HOOC—R 1 —COOZ
[0078] where
[0079] R 0 =alkyl or aliphatic hydrocarbon, normal or branched, saturated or unsaturated, substituted or unsubstituted, C chain≧4C,
[0080] R 1 =alkyl substituted amino acid moiety; or —(NH—CHX—CO) n —H—CHX—
[0081] where n≧1, X=amino acid sidechain; or alkyl—NHCOR′ where R′=aliphatic hydrocarbon, normal or branched, saturated or unsaturated, substituted or unsubstituted, C chain ≧4C
[0082] Z=H or other cationic counterion
[0083] Structure commonly shared by carboxylic acid and salts:
R—COOZ
[0084] where:
[0085] R=alkyl or aliphatic hydrocarbon, normal or branched, saturated or unsaturated, substituted or unsubstituted, with or without esterification, with or without etherification, C chain ≧4C.
[0086] Z=H or other cationic counterion
[0087] Structure commonly shared by sulfonic acid derivatives:
RCO—NR 1 —(CH 2 ) n —SO 3 Z
or
alkyl aryl—SO 3 Z
or
R—SO 3 Z
or
ROOC—(CH 2 ) n —CH SO 3 —COOZ
or
[RCO—NH—(OCH 2 ) n —OOC—CH SO 3 —COO]2Z
or
R (OCH 2 CH 2 ) n —SO 3 Z
[0088] where
[0089] R=alkyl or aliphatic hydrocarbon, normal or branched, saturated or unsaturated, substituted or unsubstituted, with or without esterification, with or without etherification, with or without sulfonation, with or without hydroxylation, C chain≧4C;
[0090] R 1 =alkyl or hydroxy alkyl,C chain≧1C;
[0091] n≧1;
[0092] Z=H or other counterion.
[0093] Structure commonly shared by sulfuric acid derivatives:
R—O SO 3 Z
[0094] where
[0095] R=aliphatic hydrocarbon, normal or branched, saturated or unsaturated, substituted or unsubstituted, with or without esterification, with or without etherification, with or without sulfonation, with or without hydroxylation, with or without ethoxylation or propoxylation, C chain≧4C
[0096] Z=H or other counterion.
[0097] Structure commonly shared by phosphoric acid derivatives:
R—O PO 3 Z
[0098] where
[0099] R=aliphatic hydrocarbon, normal or branched, saturated or unsaturated, substituted or unsubstituted, with or without esterification, with or without etherification, with or without sulfonation, with or without hydroxylation, with or without ethoxylation or propoxylation, C chain≧4C
[0100] Z=H or other counterion.
[0101] With regard to the cationics, these are surfactants with a positively charged nitrogen atom on the hydrophobic end. The charge may be permanent and non pH dependent (such as quaternary ammonium compounds) or pH dependent (such as cationic amines). They include alkyl substituted ammonium salts, heterocyclic ammonium salts, alkyl substituted imidazolinium salts and alkyl amines.
[0102] Structure commonly shared by this group:
N + R 4 Z −
[0103] where:
[0104] R=H, alkyl, hydroxyalkyl, ethoxylated and/or propoxylation alkyl, benzyl, or aliphatic hydrocarbon, normal or branched, saturated or unsaturated, substituted or unsubstituted, with or without esterification, with or without etherification, with or without sulfonation, with or without hydroxylation, with or without carboxylation, with or without ethoxylation or propoxylation, C chain≧4C
[0105] Z=H or other counterion.
[0106] With regard to the nonionics, in this group the molecule has no charge. The hydrophilic end often contains a polyether (polyoxyethylene) or one or more hydroxyl groups. They generally include alcohols, alkylphenols, esters, ethers, amine oxides, alkylamines, alkylamides, polyalkylene oxide block copolymers.
Modified Polysaccharides Containing Amphiphilic Hydrocarbons
[0107] Two primary methods are envisioned for incorporating amphiphilic moieties into the polysaccharide based materials. In the first scheme the amphiphilic moieties are added via reaction between a functional group on the polysaccharide and a second functional group attached to the reagent containing the amphiphilic moiety. The polysaccharides may be derivatized or non-derivatized, cationic or non-cationic. The general reaction scheme is defined as follows:
Polysac—Z 1 +Z 2 —R 1 →Polysac—Z 3 R 1
[0108] where:
[0109] Z 1 =functional group attached to the polysaccharide molecule and may be present either from the natural state or from a derivatization process. Examples of Z 1 functional groups include but are not limited to —OH, —NH 2 , —COOH, —CH 2 X (X=halogen), —CN, —CHO, —CS 2 .
[0110] Z 2 =Functional group attached to the R 1 moiety whose purpose is to react with a Z 1 functional group thereby attaching the R 1 moiety covalently to the polysaccharide.
[0111] Z 3 =Bridging ligand formed as a result of reaction of Z 1 with Z 2 .
[0112] R 1 =any organofunctional group with the only limitation being that R 1 must contain a moiety consisting of an amphiphilic hydrocarbon, normal or branched, saturated or unsaturated, substituted or unsubstituted, with or without esterification, with or without etherification, with our without sulfonation, with or without hydroxylation, with or without ethoxylation or propoxylation, C chain≧4 carbons.
[0113] Such materials in general will have a macroscopic structure as shown in FIG. 1 where the amphiphilic moieties are attached in a pendant fashion to the polysaccharide. Where decreased water solubility becomes an issue a second moiety, containing only a hydrophyllic portion may be attached to the polysaccharide. Examples of such materials would include ethylene glycol and its oligomers and polymers.
[0114] In theory the Z 2 —R 1 reactant could be difunctional of the form Z 2 —R 2 —Z 2 , however, in the case of high molecular weight polysaccharides this crosslinking could lead to water insoluble products, suitable for coatings but not useful for wet end applications.
[0115] Synthesis of modified polysaccharides similar to those in FIG. 1 could be prepared via a number of methods. Attachment of the amphiphilic hydrocarbon moiety could be achieved via the following paths:
[0116] (1) Modified cationic polysaccharides prepared via reaction with one of the following or similar reagents:
[0117] Where R 1 , R 2 , R 3 are any alkyl groups, chosen such that at least one of R 1 , R 2 , or R 3 is an amphiphilic hydrocarbon, normal or branched, saturated or unsaturated, substituted or unsubstituted, with or without esterification, with or without etherification, with our without sulfonation, with or without hydroxylation, with or without ethoxylation or propoxylation, C chain≧4 carbons.
[0118] (2) Dialdehyde polysaccharides, particularly dialdehyde starches, cationic or non-cationic, modified with fatty acid groups via reaction of the aldehyde groups with alcohols, amines, sulfinic acids, sulfyhydryl compounds and the like containing a linear or branched, saturated or unsaturated, substituted or non-substituted C 8 or higher aliphatic hydrocarbon moiety.
[0119] Ethoxylated fatty acid derivatives of the form:
HO—(CH 2 CH 2 O) n R 6
[0120] where R 6 is an organofunctional radical containing a linear or branched, saturated or unsaturated, substituted or non-substituted C 8 or higher aliphatic hydrocarbon moiety, can be used to directly incorporate amphiphilic functionality onto the polysaccharide backbone as shown below.
[0121] (3) Direct reaction of a functionalized linear or branched, saturated or unsaturated, substituted or non-substituted amphiphilic hydrocarbon moiety with the hydroxyl or amine groups on the polysaccharide. An example of such a reaction is shown below for chitosan:
[0122] (4) Graft polymerization of hydrophobic and or hydrophilic units onto the polysaccharide backbone. Modified vinyl monomers are capable of being grafted onto polysaccharide backbones as has been demonstrated for various starches. Use of modified vinyl monomers such as:
[0123] where:
[0124] R 2 =H, C 1-4 alkyl.
[0125] R 4 =Z 2 —R 6 where:
[0126] Z 2 =Ar, CH 2 , COO—, CONH—, —O—, —S—, —OSO 2 O—, —CONHCO—, —CONHCHOHCHOO—, any radical capable of bridging the R 6 group to the vinyl backbone portion of the molecule.
[0127] R 6 =any aliphatic, linear or branched, saturated or unsaturated, substituted or non-substituted amphiphilic hydrocarbon.
[0128] In the second scheme the amphiphilic hydrocarbon moieties are added via reaction between a functional group on the polysaccharide and a second functional group attached to the reagent containing the amphiphilic hydrocarbon moiety, however in this case two functional groups are attached to amphiphilic hydrocarbon containing reagent. The polysaccharides may be derivatized or non-derivatized, cationic or non-cationic. The general reaction scheme is defined as follows:
Polysac—Z 1 +Z 2 —R 1 —Z 2 →—Polysac—Z 3 R 1 —Polysac—
[0129] where:
[0130] Z 1 =functional group attached to the polysaccharide molecule and may be present either from the natural state or from a derivatization process. Examples of Z 1 functional groups include but is not limited to —OH, —NH 2 , —COOH, —CH 2 X (X=halogen), —CN, —CHO, —CS 2 .
[0131] Z 2 =Functional group attached to the R 1 moiety whose purpose is to react with a Z 1 functional group thereby attaching the R 1 moiety covalently to the polysaccharide.
[0132] R 1 =any organofunctional group with the only limitation being that R 1 must contain a moiety consisting of a saturated or unsaturated, substituted or unsubstituted, linear or branched amphiphilic hydrocarbon.
[0133] Such materials in general will have a macroscopic structure as shown in FIG. 2.
[0134] In theory the polysaccharides could be of high molecular weight, however, the crosslinking would be expected to lead to water insoluble products, suitable perhaps for coatings but not useful for wet end applications. For wet end applications, lower molecular weight polysaccharides including the oligomers as well as the monosaccharides are better candidates for this approach.
[0135] Synthesis of modified polysaccharides similar to those in FIG. 2 could be prepared via a number of methods. A few specific examples follow:
[0136] 1) Reaction with diacids or diacid halides of the formula:
[0137] where:
[0138] Z=OH, halogen, other displaceable group.
[0139] Y=any residue chosen such that Y contains an amphiphilic moiety.
[0140] The displaceable groups on the reactants can react with either primary —OH or —NH2 groups on the saccharide to form the corresponding ester or amide.
[0141] 2) Reaction between dialdehyde polysaccharides, cationic or non-cationic and residues chosen from the group of difunctional amphiphilic hydrocarbons where these residues are incorporated into the polysaccharide via reaction with the aldehyde groups on the starch. An example is shown below.
[0142] It will be appreciated that the foregoing examples, given for purposes of illustration, shall not be construed as limiting the scope of this invention, which is defined by the following claims and all equivalents thereto.
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Modified polysaccharides (such as starches, gums, chitosans, celluloses, alginates, sugars, etc.), which are commonly used in the paper industry as strengthening agents, surface sizes, coating binders, emulsifiers and adhesives, can be combined into a single molecule with amphiphilic hydrocarbons (e.g. surface active agents) which are commonly utilized in the paper industry to control absorbency, improve softness, enhance surface feel and function as dispersants. The resulting molecule is a modified polysaccharide having surface active moieties which can provide several potential benefits, depending on the specific combination employed, including: (a) strength aids that do not impart stiffness; (b) softeners that do not reduce strength; (c) wet strength with improved wet/dry strength ratio; (d) debonders with reduced Tinting and sloughing; (e) strength aids with controlled absorbency; and (f) surface sizing agents with improved tactile properties.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of and claims priority to U.S. application Ser. No. 14/726,897 filed on Jun. 1, 2015, which claims benefit of U.S. Provisional Application No. 62/007,159, filed on Jun. 3, 2014, the entire contents of which is hereby incorporated by reference for all purposes.
FIELD OF THE INVENTION
[0002] The present invention relates to tumor-specific, peptide-drug conjugates and pharmaceutical compositions which include the conjugates. The invention further relates to use of such conjugates and compositions as antitumor agents for the treatment of cancer in mammals, particularly humans.
BACKGROUND AND RELATED ART
[0003] Cancerous cells often over-express certain proteases compared to normal cells. This has prompted efforts to target cancerous cells by linking a cytotoxic therapeutic agent to a peptide that a tumor protease cleaves, to release the cytotoxic drug proximate to or within cancerous cells while sparing or less substantially impacting normal cells.
[0004] U.S. Pat. No. 6,214,345 discloses tumor-specific peptide-drug conjugates that include a self-immolating linker and are selectively activated at the site of a tumor, wherein the drug may be mitomycin or doxorubicin, and the self-immolating linker is p-aminobenzyl alcohol.
[0005] Cells which express asparaginases make attractive targets for the peptide-drug conjugate approach, because many tumors over-express these proteases. One such asparaginase, legumain, has attracted particular attention in this connection (Wu et al., Cancer Research 2006; 66: 970-980; Liu et al., Cancer Research 2003; 63: 2957-2964; Bajjuri et al., ChemMedChem. 2011; 6:.doi:10.1002/cmdc.201000478; http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3549592/pdf/ni hm 54-59 s-340268.pdf.).
[0006] Mitomycin, doxorubicin and camptothecin have attracted attention as drugs employed in peptide-drug conjugate therapies. U.S. Pat. No. 7,608,591; US Published Application 20110300147; US Published Application 20090175873; and U.S. Pat. No. 8,314,060 disclose examples of peptide-drug conjugates that target legumain with drugs that include doxorubicin.
[0007] Each of the above references is hereby incorporated by reference in its entirety.
[0008] These previous approaches have generally involved chemical modification of the drug moiety, which can adversely affect the drug's efficacy. Coupling of peptides directly (through the C-terminal carboxyl group) to the aziridine N atom of mitomycin yields a secondary amide, a functional group that typically is not subject to attack by proteases. Moreover, studies on mitomycin indicate the role of an NH group in the aziridine ring for biological activity. Thus there is a need for improved conjugates which target anti-tumor drugs such as mitomycin to tumor cells which express legumain and other asparaginases.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a graph showing the rate of decay of N α -succinamic acid-Ala-Ala-Asn-PABC-mitomycin [conjugate 8 herein] as a function of time when exposed to human plasma.
[0010] FIG. 2 is a graph showing the body weight of Balb/c mice as a function of time after administration of N α -succinamic acid-Ala-Ala-Asn-PABC-mitomycin.
[0011] FIG. 3 is a graph showing the tumor growth curve of the subcutaneous CT-26 syngenic colon cancer model in Balb/c mice after administration of N α -succinamic acid-Ala-Ala-Asn-PABC-mitomycin.
SUMMARY OF THE INVENTION
[0012] Certain embodiments of the invention are peptide-drug conjugates. Such conjugates comprise, generally: 1) a peptide moiety that can be cleaved by cellular proteases, bound to 2) a self-immolating linker, in particular p-aminobenzyl carbamoyl or p-aminobenzyl carbonate moiety, which is in turn bound to 3) a cytotoxic drug moiety. In these embodiments, the linker moiety is attached to an asparagine residue, at which position proteolytic cleavage occurs.
[0013] In particular embodiments, the peptide-drug conjugates have the structure of Formula 1 below:
[0000] R-Y-Z-Asn-Linker-D (Formula I)
[0000] wherein
R comprises a substituent selected from the group consisting of
i) an acyl group, a carbamoyl group, a sulfonyl group, phosphoryl group or an alkyl group derived from a C 1 to about C 20 linear, branched or alicyclic carboxylic acid, optionally substituted with from one to about five hydroxyl, amine, carboxyl, sulfonic, or phosphoryl groups, ii) a peptide with one to about fifty L- or D-amino acid residues, and iii) a polyethylene glycol with a molecular weight from 400 to about 40,000;
Y is an amino acid residue selected from the group consisting of Ala, Thr, Ser, Leu, Arg, Pro, Val, Tyr, Phe;
Z is an amino acid residue selected from the group consisting of Ala, Thr, Asn and Pro;
Asn is an asparagine residue;
Linker is a p-aminobenzyl carbamoyl moiety or a p-aminobenzyl carbonate moiety;
D is an anti-tumor drug moiety bonded to the Linker moiety, wherein the drug is selected from the group consisting of mitomycin, doxorubicin, aminopterin, actinomycin, bleomycin, 9-amino-camptothecin, N 8 -acetyl spermidine, 1-(2-chloroethyl)-1,2-dimethanesulfonyl hydrazide, tallysomycin, cytarabine, etoposide, camptothecin, taxol, esperamicin, Podophyllotoxin, anguidine, vincristine, vinblastine, morpholine-doxorubicin, n-(5,5-diacetoxy-pentyl) doxorubicin, and derivatives thereof.
[0017] In particular embodiments of Formula I:
[0000] R comprises a substituent selected from the group consisting of
i) an acyl group derived from a C1 to about C20 linear, branched or alicyclic carboxylic acid, optionally substituted with from one to about five hydroxyl, amine, carboxyl, sulfonic, or phosphoryl groups,
ii) a peptide with one to about fifty L-amino acid residues, and
iii) a polyethylene glycol with a molecular weight from 400 to about 40,000;
Y is an amino acid residue selected from the group consisting of Ala, Thr, Ser, Leu, Arg, Pro, Val, Tyr, Phe;
Z is an amino acid residue selected from the group consisting of Ala, Thr, Asn and Pro;
Asn is an asparagine residue;
Linker is a p-aminobenzylcarbamoyl moiety;
D is an anti-tumor drug moiety, wherein the drug is selected from the group consisting of mitomycin and doxorubincin.
[0018] In other particular embodiments of Formula I:
[0000] R comprises a substituent selected from the group consisting of
i) an acyl group, a carbamoyl group, a sulfonyl group, phosphoryl group or an alkyl group derived from a C1 to about C20 linear, branched or alicyclic carboxylic acid, optionally substituted with from one to about five hydroxyl, amine, carboxyl, sulfonic, or phosphoryl groups,
ii) a peptide with one to about fifty L- or D-amino acid residues, and
iii) a polyethylene glycol with a molecular weight from 400 to about 40,000;
Y is an amino acid residue selected from the group consisting of Ala, Thr, Ser, Leu, Arg, Pro, Val, Tyr, Phe;
Z is an amino acid residue selected from the group consisting of Ala, Thr, Asn and Pro;
Asn is an asparagine residue;
Linker is a p-aminobenzyl carbonate moiety; and
D is an anti-tumor drug moiety bonded to the Linker moiety and wherein the drug is camptothecin.
[0019] In still further embodiments, the invention comprises a dimeric peptide-drug conjugate of the formula shown in Formula II:
[0000] D′-Linker-Asn-Z—Y—R′—Y—Z-Asn-Linker-D (Formula II)
[0020] Wherein D and D′ are cytotoxic drug moieties which are the same are different from one another and are independently selected from the group consisting of mitomycin, doxorubicin, aminopterin, actinomycin, bleomycin, 9-amino-camptothecin, N 8 -acetyl spermidine, 1-(2-chloroethyl)-1,2-dimethanesulfonyl hydrazide, tallysomycin, cytarabine, etoposide, camptothecin, taxol, esperamicin, Podophyllotoxin, anguidine, vincristine, vinblastine, morpholine-doxorubicin, n-(5,5-diacetoxy-pentyl) doxorubicin, and derivatives thereof;
[0021] Linker is a p-aminobenzyl carbamate moiety or p-aminobenzyl carbonate moiety, wherein the linkers may be the same or different;
[0000] R′ comprises a substituent selected from the group consisting of
i) a bis-functional group selected from an acyl group, a carbamoyl group, a sulfonyl group, phosphoryl group or an alkyl group derived from a C 1 to about C 20 linear, branched or alicyclic carboxylic acid, optionally substituted with from one to about five hydroxyl, amine, carboxyl, sulfonic, or phosphoryl groups,
ii) a peptide with one to about fifty L or D-amino acid residues, and
iii) a polyethylene glycol with a molecular weight from 400 to about 40,000; and
Y is an amino acid residue selected from the group consisting of Ala, Thr, Ser, Leu, Arg, Pro, Val, Tyr, Phe;
Asn is an asparagine residue; and
Z is an amino acid residue selected from the group consisting of Ala, Thr, Asn and Pro.
[0022] As will be appreciated, the conjugates of Formula II are essentially dimeric versions of the conjugates of Formula I, which can target two molecules of cytotoxic drug per conjugate to the targeted cells or tissue.
[0023] In further embodiments, the invention comprises a pharmaceutical composition which comprises at least one peptide-drug conjugate of Formula I or Formula II in at least one pharmaceutically-acceptable carrier.
[0024] In still further embodiments, the invention comprises a method of treating cancer in a mammal, which may be a human, which comprises administering an anti-tumor effective amount of the conjugate or pharmaceutical composition of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] “Mitomycin” as used here refers to members of the family of aziridine-containing drugs isolated from Streptomyces caespitosus or Streptomyces lavendulae , and includes specifically mitomycin C and mitomycin A.
[0026] “Doxorubicin” as used herein refers to members of the family of Anthracyclines derived from Streptomyces bacterium Streptomyces peucetius var. caesius , and includes doxorubicin, daunorubicin, epirubicin and idarubicin.
[0027] “Camptothecin” as used here refers to members of the family of alkaloids isolated from Camptotheca acuminata and its chemical derivatives, and includes camptothecin, irinotecan, topotecan and rubitecan.
[0028] The present invention provides tumor-specific, peptide-drug conjugates comprising a peptide moiety, a self-immolating linker which is p-aminobenzyl-carbamoyl or p-aminobenzyl carbonate (depending on the type of functional group contained in the drug to which the self-immolating linker is attached), and a cytotoxic drug moeity. The conjugates act as prodrugs in the sense that the conjugate is substantially inactive and non-toxic. The peptide moiety can be selectively cleaved by a protease enzyme in vivo to free the self-immolating linker/cytotoxic drug moiety. Upon such enzymatic cleavage, the self-immolating linker spontaneously hydrolyzes to yield the free drug in its active form, but more directed at the targeted milieu, such as the site of a tumor in a human patient. In this manner, the cytotoxic drug is targeted to a particular site in need of treatment, while cellular and tissue damage at sites other than the targeted site is reduced.
[0029] The cytotoxic drug moiety has a chemically reactive functional group by means of which the drug backbone is covalently bonded to the self-immolating linker. The functional group which links the cytotoxic drug to the self-immolating linker is such that, upon hydrolysis of the self-immolating linker, the cytotoxic drug is released in cytotoxically-active form. Such functional group may include, for example a primary amine, a secondary amine or hydroxyl. Cytotoxic drugs include mitomycin, doxorubicin, aminopterin, actinomycin, bleomycin, 9-amino-camptothecin, N 8 -acetyl spermidine, 1-(2-chloroethyl)-1,2-dimethanesulfonyl hydrazide, tallysomycin, cytarabine, etoposide, camptothecin, taxol, esperamicin, Podophyllotoxin, anguidine, vincristine, vinblastine, morpholine-doxorubicin, n-(5,5-diacetoxy-pentyl) doxorubicin, and derivatives thereof. Preferred embodiments are based on mitomycin, doxorubincin and/or camptothecin.
[0030] In specific embodiments where the drug (D) is mitomycin, the peptide-drug conjugates have the structure as shown in Formula III (wherein R is defined as above and Ala is an alanine residue):
[0000]
[0031] In specific embodiments where the drug (D) is doxorubicin, the peptide-drug conjugates have the structure as shown in Formula IV (wherein R is defined as above and Ala is an alanine residue):
[0000]
[0032] In specific embodiments where the drug (D) is camptothecin, the peptide-drug conjugates have the structure as shown in Formula V (wherein R, is defined as above and Ala is an alanine residue):
[0000]
[0033] In specific embodiments of dimeric conjugates where the drug (D) is mitomycin and drug (D′) is doxorubicin, the peptide-drug conjugates have the structure as shown in Formula VI (wherein R′ is defined as above and Ala is an alanine residue)
[0000]
[0034] In specific embodiments of dimeric conjugates where the drug (D) is mitomycin and drug (D′) is camptothecin, the peptide-drug conjugates have the structure as shown in Formula VII (wherein R′ is defined as above and Ala is an alanine residue):
[0000]
[0035] Preferred conjugates of the invention include:
Ala-Ala-Asn-PABC-mitomycin N α -succinamic acid-Ala-Ala-Asn-PABC-mitomycin: N α -acetamide-Ala-Ala-Asn-PABC-mitomycin; N α -butyramide-Ala-Ala-Asn-PABC-mitomycin; N α -hexanamide-Ala-Ala-Asn-PABC-mitomycin; N α -[-(2-amide-2-oxoethoxy) acetic acid]-Ala-Ala-Asn-PABC-mitomycin; and N α -[-((2-amide-2-oxoethoxy)(methyl) amino) acetic acid]-Ala-Ala-Asn-PABC-mitomycin; Ala-Ala-Asn-PABC-doxorubicin; N α -succinamic acid-Ala-Ala-Asn-PABC-doxorubicin; N α -acetamide-Ala-Ala-Asn-PABC-doxorubicin; N α -butyramide-Ala-Ala-Asn-PABC-doxorubicin; and N α -hexanamide-Ala-Ala-Asn-PABC-doxorubicin; N α -[-(2-amide-2-oxoethoxy) acetic acid]-Ala-Ala-Asn-PABC-doxorubicin; and N α -[-((2-amide-2-oxoethoxy)(methyl) amino) acetic acid]-Ala-Ala-Asn-PABC-doxorubicin; Wherein PABC is a p-aminobenzyl carbamoyl linker moiety.
[0049] Other preferred conjugates of the invention include:
Ala-Ala-Asn-PABC-camptothecin; N α -succinamic acid-Ala-Ala-Asn-PABC-camptothecin; N α -[-(2-amide-2-oxoethoxy) acetic acid]-Ala-Ala-Asn-PABC-camptothecin; and N α -[-((2-amide-2-oxoethoxy)(methyl) amino) acetic acid]-Ala-Ala-Asn-PABC-camptothecin
[0054] Wherein PABC is a p-aminobenzyl carbonate moiety.
[0055] Preferred dimeric conjugates include:
N 1 -Ala-Ala-Asn-PABC-mitomycin, N 4 -Ala-Ala-Asn-PABC-doxorubicin-succinamide: N 1 -Ala-Ala-Asn-PABC-mitomycin, N 5 -Ala-Ala-Asn-PABC-doxorubicin-bis(O α )-acetamide: N 1 -Ala-Ala-Asn-PABC-mitomycin, N 5 -Ala-Ala-Asn-PABC-doxorubicin-bis(N α -methyl)-acetamide; N 1 -Ala-Ala-Asn-PABC-mitomycin, N 4 -Ala-Ala-Asn-PABC-camptothecin-succinamide; N 1 -Ala-Ala-Asn-PABC-mitomycin, N 5 -Ala-Ala-Asn-PABC-camptothecin-bis(O α -acetamide; and N 1 -Ala-Ala-Asn-PABC-mitomycin, N 5 -Ala-Ala-Asn-PABC-camptothecin-bis(N α -methyl)-acetamide.
[0062] Wherein PABC is a p-aminobenzyl carbamoyl or p-aminobenzyl carbonate linker moiety.
Preparation of Peptide-Drug Conjugates
[0063] In general, the peptide-drug conjugates of Formula I and Formula II may be prepared using available materials and conventional organic synthesis techniques. For example, cytotoxic drugs of the type described are commercially-available and their synthesis is described in the scientific literature.
[0064] Generally, the peptide-drug conjugates of the present invention may be constructed by covalently attaching the drug moiety to the peptide sequence through the self-immolating linker. The specific synthetic routes of preparation shown below are exemplary of those which may be utilized.
[0065] Synthesis scheme 1 shows a synthetic route for producing peptide-mitomycin conjugates:
[0000]
[0066] Synthesis scheme 2 shows a synthetic route for producing peptide-doxorubicin conjugates:
[0000]
[0067] Synthesis Scheme 3 shows a synthetic route for producing peptide-camptothecin conjugates:
[0000]
[0068] Synthesis Scheme 4 shows a synthetic route for producing doxorubicin-peptide-mitomycin conjugates (dimeric conjugate):
[0000]
[0069] Synthesis Scheme 5 shows a synthetic route for producing camptothecin-peptide-mitomycin conjugates (dimeric conjugates):
[0000]
[0070] In general for the described synthesis reactions:
[0000] a) Standard peptide synthesis methods were employed for Fmoc and trityl deportation, and peptide coupling;
b) The self-mmolating linker was attached to amino acid by reacting N α -Fmoc-Asn or trityl protected N α -Fmoc-Asn with p-aminobenzyl alcohol, using EEDQ as coupling reagent in organic/aqueous solvent mixture;
c) The activated carbonate of p-aminobenzyl alcohol could be obtained by reacting p-nitrophenyl chloroformate with N α -Fmoc-Asn-PAB-OH or N α -Fmoc-Ala-Ala-N-Trityl-Asn-PAB-OH;
d) Peptide drug conjugates of mitomycin and doxorubicin were obtained by reacting with corresponding activated carbonate of N α -Fmoc-Asn-PABC-PNP or N α -Fmoc-Ala-Ala-Asn-PABC-PNP in DMF in the presence of HOBT;
e) For the synthesis of camptothecin conjugates, camptothecin was reacted with triphosgene to provide canptothecin chloroformate in situ, which was then coupled with N α -Fmoc-Asn-PAB-OH to obtain corresponding N α -Fmoc-Asn-PABC-camptothecin;
f) The final peptide-drug conjugates were obtained by acylation with various anhydrides, acyl chlorides or carboxylic acids by peptide coupling methods.
[0071] Synthesized final conjugates can be purified by various methods including silica column chromatography, HPLC, ion exchange chromatography, acid/base precipitation and crystallization.
[0072] The final conjugates may be characterized by 1 H-NMR, 13 C-NMR, MS, LC/MS, UV/VIS, and/or IR.
[0073] Many of the disclosed conjugates can exist as hydrochloride or other salts. Those skilled in medicinal chemistry will appreciate that the choice of salt is not critical, and other pharmaceutically-acceptable salts can be prepared by well-known methods and can be utilized in the preparation of pharmaceutical compositions. See, e.g., Handbook of Pharmaceutical Salts: Properties, Selection and Use. (P. Heinrich Stahl and Camille G. Wermuth, eds.) International Union of Pure and Applied Chemistry, Wiley-VCH 2002 and L. D. Bighley, S. M. Berge, D. C. Monkhouse, in “Encyclopedia of Pharmaceutical Technology’. Eds. J. Swarbrick and J. C. Boylan, Vol. 13, Marcel Dekker, Inc., New York, Basel, Hong Kong 1995, pp. 453-499.
[0074] In addition, those skilled in the art will appreciate that not only a variety of salts can be produced and used, but also, hydrates, solvates, and polymorphs can be produced from the conjugates disclosed herein. Also, various isotopically-substituted variants (through, e.g., substitution of deuterium for hydrogen, 13 C for carbon, 15 N for nitrogen) can also be readily produced. Such derivatives are contemplated within the scope of this disclosure.
[0075] To prepare the pharmaceutical compositions of the invention, one or more of the conjugates is combined with at least one pharmaceutically acceptable carrier. “Pharmaceutically acceptable carriers” refer to biocompatible compounds that are suitable for a particular route of administration for a pharmacologically effective substance. They include stabilizing agents, wetting and emulsifying agents, salts for varying osmolarity, encapsulating agents, buffers, and skin penetration enhancers. Examples of pharmaceutically acceptable carriers are described in Remington's Pharmaceutical Sciences (Alfonso R. Gennaro, ed., 18 th edition, 1990). The particular choice of carrier(s) depends upon the specific therapy which is contemplated. Various formulations for pharmaceutical compositions and components thereof are described in US published patent application 2014/0057844, the disclosure of which is incorporated by reference.
[0076] The selection of cytotoxic drug moiety in the conjugates is guided by the type of cancer to be treated. For treatment of a specific type of cancer or tumor, the cytotoxic drug moiety should be based on a cytotoxic drug effective to treat such type of cancer. For example, the drug conjugates based on mitomycin may be used to treat cancers in accordance with, or guided by, mitomycin administration protocols which are currently known and recommended in the art.
[0077] The conjugates, compositions, and methods of the invention may be used to treat different types of cancers, including but not limited to bladder cancer, breast cancers, cervical cancer, ovarian cancer, stomach cancer, pancreatic cancer, lung cancer, liver cancer, oesophageal cancer, bowel cancer; skin cancer, and prostate cancer.
[0078] Routes of administration include injection, oral administration, buccal administration, parenteral administration, inhalation, and rectal administration.
[0079] Dosage of the conjugates to be administered, and particular routes and regimens of administration, depend upon the type of cancer to be treated and the circumstances of particular cancer conditions, but can be determined by persons skilled in the art.
[0080] The conjugates of the invention may be used in combination with each other and in combination with other chemotherapeutic agents or treatments. For example, a therapy using the conjugates of the invention may be used in combination with radiation therapy.
[0081] The examples which follow illustrate certain embodiments of the invention and should be considered as illustrative but not limiting on the scope of the invention.
EXAMPLES
Biological Activity
[0082] Representative peptide-drug conjugates of the present invention were tested in both in vitro and in vivo system to determine their biological activity. In these tests, the potency of the conjugates of the cytotoxic drugs was determined by measuring the cytotoxicity of the conjugates against cells of human cancer origin. One skilled in the art will recognize that any tumor cell line expressing the desired tumor associated proteases (proteases which cleave the conjugates of the invention to release drug in active form) could be used instead of the specific tumor cell lines used in the following analysis. The following describes representative tests used and the results obtained.
Test I
Human Plasma Stability
[0083] 20 μL of 500 μM peptide-drug conjugate N α -succinamic acid-Ala-Ala-Asn-PABC-mitomycin [herein compound 8] in DMSO stock solution was diluted to 1 mL with human plasma (final concentration: 10 μM, 2% DMSO), and the mixture was incubated at 37° C. 100 μL aliquots were removed at the time points of 0, 0.25, 0.5, 1, 2, 4, 6 hours and diluted with 400 μL cold acetonitrile containing tolbutamide (200 ng/mL) as internal standard. The samples were centrifuged at 14,000 rpm for 4 minutes. 100 μL of above supernatants were diluted with 300 μL of 0.1% formic acid HPLC water and 10 μL was taken for LC/MS/MS analysis (column: C-18; mobile phase: 0.1% formic acid in water/0.1% formic acid in acetonitrile; ion transition: Q1 ion (m/z)=840.5, Q2 ion (m/z)=462.2). As shown in FIG. 1 , the peptide-drug conjugate is relatively stable in human plasma with a half life greater than 15 hours (T1/2>15 h). Less than 2% of free drug mitomycin was detected.
Test II
In Vitro Cytotocxicity Assay
[0084] Monolayer cultures of human carcinoma cells were harvested using trypsin-EDTA, and the cells counted and resuspended to 1×10 5 /mL in RPMI-1640 or DMEM containing 10% FBS. Cells (0.1 mL/well) were added to each well of 96 well microtiter plates and incubated overnight at 37° C. in a humidified atmosphere of 5% CO 2 . Media was removed from the plates and serial dilutions of mitomycin or conjugates in medium (final DMSO concentration <0.1%) was added to the wells. All dilutions were performed in triplicate. The drug treated cells were incubated for another 72 hours at 37° C. in a humidified atmosphere of 5% CO 2 . 50 μL of cold TCA (50%, wt/vol) was added to each well and incubated the plates at 4° C. for 1 hour. The plates were washed with slow-running tap water for three times and the dried at room temperature. 50 μL of Sulforhodamine B solution (0.4%, wt/vol) was added to each well and the plates were left at room temperature for 1 hour. The plates were rinsed with acetic acid solution (1%, vol/vol) to remove the unbound dye and dried at room temperature. 200 μL of 10 mM Tris base solution was added to each well and the plates were shaken on a gyratory shaker for 15 minutes to solubilize the protein-bound dye. Well optical density at 510 nm was measured in a microplate reader, and the IC 50 was calculated by GraphPad from three separated experiments with triplicate in each experiment and expressed as mean (Table 1).
[0000]
TABLE 1
IC 50 (μM, n = 3)
Sample
HCT116
HepG2
mitomycin
0.116
0.143
N α -succinamicacid-Ala-Ala-Asn-PABC-mitomycin
6.65
2.48
[compound 8]
N α -acetamide-Ala-Ala-Asn-PABC-mitomycin
5.37
4.17
[compound 9]
N α -butyramide-Ala-Ala-Asn-PABC-mitomycin
8.85
8.16
[compound 10]
N α -hexanamide-Ala-Ala-Asn-PABC-mitomycin
5.95
4.91
[compound 11]
[0085] The HCT116 and HepG2 human carcinoma cell lines assays reveal that the cytoxicity of peptide-drug conjugates was reduced by 76- to 17-fold as compared with parent drug mitomycin, depending on different tumor cell lines. Tumor associated protease legumain is over-expressed in the tumor microenvironment of solid tumor in hypoxic and acidic conditions. However, some level of legumain expression of both HCT116 and HepG2 cell lines in cell culture was previously reported, which may result in the residual activity of peptide-drug conjugate as observed in this assay.
Test III
In Vivo Maximum Tolerated Dose (MTD) in Balb/c Mice
[0086] The tolerability of mitomycin and its peptide-drug conjugate N α -succinamic acid-Ala-Ala-Asn-PABC-mitomycin [compound 8] as single agent were evaluated separately in Balb/c mice. The results of body weights in different groups at different time points after treatment are shown in FIG. 2 .
[0087] In 10 mg/kg, once per week dose group of mitomycin, animal death was observed. In the 5 mg/kg group, the mice displayed behaviors of piloerection and retardation. The body weight loss (>15%) was observed in 5 mg/kg mitomycin group. Meanwhile, no abnormal appearance and body weight (<10%) was observed for peptide-drug conjugate N α -succinamic acid-Ala-Ala-Asn-PABC-mitomycin [8] at the dose groups of 25, 50 and 100 mg/kg, once per week, three injections total for 24 days. The murine toxicity study revealed that peptide-drug conjugate N α -succinamic acid-Ala-Ala-Asn-PABC-mitomycin [8] is much less toxic than parent drug mitomycin in vivo. The mice maximum tolerated dose (MTD) of peptide-drug conjugate increases by at least 20-fold as compared with the parent drug mitomycin.
Test IV
In Vivo Antitumor Activity
[0088] The tumoricidal effect of peptide-drug conjugate N α -succinamic acid-Ala-Ala-Asn-PABC-mitomycin [8] was evaluated on subcutaneous CT-26 syngenic colon cancer model in Balb/c mice. Each mouse was inoculated subcutaneously at the right flank region with CT-26 tumor cells (5×10 5 ) in 0.1 mL of PBS. When the mean tumor size reached approximately 180 mm 3 (after around 10 days), the CT-26 tumor mice were treated through intravenous administration with: vehicle (2% DMA and 98% of 40% 2HP-β-CD), mitomycin (2 mg/kg; 5 mg/kg, QW) and conjugate N α -succinamic acid-Ala-Ala-Asn-PABC-mitomycin [8] (25 mg/kg; 50 mg/kg, QW) for three weeks, total of three injections per mouse. The tumor growth curve of CT-26 model is shown in FIG. 3 .
[0089] As reported previously, even though CT-26 cells has week expression of tumor associated protease legumain in vitro, it is abundantly expressed in vivo in TMEs on the surface of viable endothelial cells and tumor-associated macrophages in CT-26 solid tumor microenvironment, as the legumain expression is induced under hypoxia and stress condition. Legumain specific activation conjugate N α -succinamic acid-Ala-Ala-Asn-PABC-mitomycin [8] demonstrated strong antitumor efficacy on subcutaneous CT-26 syngenic colon cancer model in Balb/c mice as shown in FIG. 3 . At 50 mg/kg, dose, which is much lower than its MTD, the conjugate significantly inhibits the tumor growth versus untreated control (T/C=36.4%, p<0.01). While at its MTD dose (5 mg/kg), the parent drug mitomycin demonstrated much weaker tumor growth inhibition effect (T/C=50.4%). Therefore, in vivo experiments show that the peptide-mitomycin conjugate of the present invention produce antitumor activity with greater potency and less toxicity to the host than parent drug mitomycin.
SYNTHESIS EXAMPLES
Example 1
Preparation of N α -Fmoc-Ala-Ala [1]
[0090] A solution of N α -Fmoc-Ala (1.58 g, 5.0 mmoles), N-hydroxyl succinimide (0.63 g, 5.5 mmoles) and DCC (1.03 g, 5.0 mmoles) in CH 2 Cl 2 (50 mL) were stirred at 5° C. for 6 hours. The DCU was filtered out and the filtrate was concentrated. Residue was re-dissolved in THF (50 mL) and kept in refrigerator (4° C.) overnight. More DCU was filtered off and the THF solution was added to a solution of alanine (0.99 g, 7.5 mmoles) and NaHCO 3 (1.68 g, 20 mmoles) in 25% THF/H 2 O (80 mL). The reaction mixture was stirred vigorously at 25° C. for 5 hours. THF was removed by concentration and the aqueous suspension was adjusted to pH4 with concentrated HCl. The aqueous suspension was stirred at 25° C. for another 3 hours and the precipitate was collected by filtration, rinsed thoroughly with de-salt water and was dried in vacuum over KOH to give a white solid product (1.77 g, 83.7% yield).
[0091] LC/MS: (MH) + =383
Example 2
Preparation of N α -Fmoc-Asn-PAB-OH [2]
[0092] A solution of N α -Fmoc-Asn (1.77 g, 5.0 mmoles), p-aminobenzyl alcohol (0.86 g, 7.0 mmoles) and EEDQ (1.48 g, 6 mmoles) in THF/H 2 O (100/20 mL) were stirred at room temperature overnight. Additional amount of EEDQ (0.61 g, 2.5 mmoles) was added and stirred for another 24 hours. THF was removed by concentration and the residue suspension was diluted with NaOH/NaHCO 3 aqueous solution (2/8 g, 200 mL) and stirred for 3 hours. The precipitate was collected by filtration, rinsed with water and re-suspended in 10% citric acid (150 mL). Precipitate was collected by filtration, rinsed with 10% citric acid followed by de-salt water and dried in vacuum. The above obtained solid was triturated in ethyl acetate (100 mL). Solid was collected by filtration and dried in vacuum to give an off-white product (0.95 g, 40% yield).
[0093] LC/MS: (MH) + =460
Example 3
Preparation of N α -Fmoc-Asn-PABC-PNP [3]
[0094] N α -Fmoc-Asn-PAB-OH [2] (0.75 g, 1.6 mmoles) in dry THF/DMF (50/5 mL) at room temperature was treated with p-nitrophenyl chloroformate (0.4 g, 2.0 mmloes) and pyridine (0.15 g, 2.0 mmoles). After 16 hours, additional amount of p-nitrophenyl chloroformate (0.2 g, 1.0 mmoles) was added and the reaction solution was stirred for another 6 hours. The above solution was diluted with ethyl acetate (250 mL) and was washed with 5% citric acid (2×100 mL) followed by brine, dried with Na 2 SO 4 , and evaporated to dryness. The residue was triturated in 50% EA/Hexane and the solid was collected by filtration to give an off-yellow product (0.8 g, 81% yield).
[0095] LC/MS: (MH) + =625
Example 4
Preparation of N α -Fmoc-Asn-PABC-mitomycin [4]
[0096] N α -Fmoc-Asn-PABC-PNP [3] (624 mg, 1.0 mmoles) and mitomycin (400 mg, 1.2 mmoles) in dry DMF (15 mL) at room temperature were treated with HOBT (675 mg, 5.0 mmoles) and DIEA (650 mg, 5.0 mmoles) for 4 hours. Reaction mixture was diluted with ethyl acetate (150 mL) and washed three times with NaOH/NaHCO 3 (1/4 g, 200 mL) followed by brine. The organic layer was dried with Na 2 SO 4 and concentrated to dryness under reduced pressure. The residue was triturated in 50% ethyl acetate/hexane (50 mL) and the solid was collected by filtration, rinsed with ethyl acetate/hexane and dried in vacuum to give a purple product (635 mg, 76.3% yield).
[0097] LC/MS: (MH) + =820
Example 5
Preparation of Asn-PABC-mitomycin [5]
[0098] N α -Fmoc-Asn-PABC-mitomycin [4] (624 mg, 0.76 mmoles) was treated with 20% morpholine/NMP (15 mL) at room temperature. After 30 minutes, 50% ethyl acetate/hexane (100 mL) was added and the supernatant was removed. The above process was repeated twice. The residue was re-dissolved in methanol (25 mL) and the solvent was evaporated under reduced pressure to dryness. Residue was triturated in 50% ethyl acetate/hexane (100 mL) and stirred at room temperature overnight. Solid was collected by filtration, rinsed the ethyl acetate/hexane and dried in vacuum to give a purple product (440 mg, 95.6% yield).
[0099] LC/MS: (MH) + =598
Example 6
Preparation of N α -Fmoc-Ala-Ala-Asn-PABC-mitomycin [6]
[0100] Asn-PABC-mitomycin [5] (440 mg, 0.73 mmoles) and N α -Fmoc-Ala-Ala [1] (286 mg, 0.75 mmoles) in NMP (15 mL) were treated with PyBop (390 mg, 0.75 mmoles) and DIEA (585 mg, 4.5 mmoles) at room temperature. After 1 hour, the reaction mixture was diluted with ethyl acetate (200 mL). The organic solution was washed with 5% citric acid (3×100 mL), brine and dried with Na 2 SO 4 . Solvent was evaporated under reduced pressure and the residue was triturated in 50% ethyl acetate/hexane (100 mL) and stirred at room temperature overnight. Solid was collected by filtration and re-suspended in ethyl acetate (50 mL) and sonicated. Solid was collected by filtration, rinsed thoroughly with ethyl acetate and dried in vacuum to give a purple product (530 mg, 75.4% yield).
[0101] LC/MS: (MH) + =962
Example 7
Preparation of Ala-Ala-Asn-PABC-mitomycin [7]
[0102] N α -Fmoc-Ala-Ala-Asn-PABC-mitomycin [6] (481 mg, 0.5 mmloes) was treated in 20% morpholine/NMP (10 mL) at room temperature. After 30 minutes, 50% ethyl acetate/hexane (150 mL) was added and stirred for 1 hour. The supernatant was removed and the residue was triturated in CH 2 Cl 2 (50 mL). Solid was collected by filtration and re-dissolved in methanol (20 mL). Solvent was evaporated under reduced pressure and the residue was triturated in ethyl acetate. Solid was collected by filtration, rinsed thoroughly with ethyl acetate and dried in vacuum to give a purple product (277 mg, 75% yield).
[0103] LC/MS: (MH) + =740
Example 8
Preparation of N α -succinamic acid-Ala-Ala-Asn-PABC-mitomycin [8]
[0104] Ala-Ala-Asn-PABC-mitomycin [7] (260 mg, 0.35 mmoles) in DMA/CH 2 Cl 2 (2/6 mL) at room temperature was treated with succinic anhydride (50 mg, 0.5 mmoles) and DIEA (130 mg, 1.0 mmoles). The reaction mixture was stirred overnight. To the above reaction mixture, ethyl ether (100 mL) was added and stirred for 30 minutes. The supernatant was removed and the process was repeated twice. The residue was triturated in 2% HOAc/ethyl acetate (50 mL) and the solid was collected by filtration, rinsed thoroughly with ethyl acetate and dried in vacuum to give a purple product (265 mg, 90% yield).
[0105] LC/MC: (M-H) − =838
Example 9
Preparation of N α -acetamide-Ala-Ala-Asn-PABC-mitomycin [9]
[0106] Ala-Ala-Asn-PABC-mitomycin [7] (37 mg, 0.05 mmoles) in DMA/CH 2 Cl 2 (1/3 mL) at room temperature was treated with acetic anhydride (10 mg, 0.1 mmoles) and DIEA (13 mg, 0.1 mmoles). After 30 minutes, ethyl ether (50 mL) was added and stirred for 60 minutes. The soft solid was collected by filtration, rinsed with ethyl ethers and re-dissolved in methanol (5 mL). Solvent was removed under reduced pressure and the residue was triturated in 50% ethyl acetate/hexane (10 mL) and the solid was collected by filtration, rinsed thoroughly with ethyl acetate/hexane, dried in vacuum to give a purple product (35 mg, 90% yield).
[0107] LC/MC: (MH) + =780; (M+Na) + =805
Example 10
Preparation of N α -butyramide-Ala-Ala-Asn-PABC-mitomycin [10]
[0108] Ala-Ala-Asn-PABC-mitomycin [7] (37 mg, 0.05 mmoles) in DMA/CH 2 Cl 2 (1/3 mL) at room temperature was treated with butyryl chloride (6.3 mg, 0.06 mmoles) and DIEA (13 mg, 0.1 mmoles). After 30 minutes, ethyl ether (50 mL) was added and stirred for 60 minutes. The solid was collected by filtration, rinsed with ethyl ethers and re-dissolved in methanol (5 mL). Solvent was removed under reduced pressure and the residue was triturated in ethyl acetate (10 mL). The solid was collected by filtration, rinsed thoroughly with ethyl acetate and dried in vacuum to give a purple product (27 mg, 67% yield).
[0109] LC/MC: (MH) + =808; (M+Na) + =833.
Example 11
Preparation of N α -hexanamide-Ala-Ala-Asn-PABC-mitomycin [11]
[0110] Ala-Ala-Asn-PABC-mitomycin [7] (37 mg, 0.05 mmoles) in DMA/CH 2 Cl 2 (1/3 mL) at room temperature was treated with hexaneoyl chloride (9.0 mg, 0.06 mmoles) and DIEA (13 mg, 0.1 mmoles). After 30 minutes, ethyl ether (50 mL) was added and stirred for 60 minutes. The solid was collected by filtration, rinsed with ethyl ethers and re-dissolved in methanol (5 mL). Solvent was removed under reduced pressure and the residue was triturated in 50% ethyl acetate/hexane (10 mL). The solid was collected by filtration, rinsed thoroughly with ethyl acetate and dried in vacuum to give a purple product (27 mg, 67% yield).
[0111] LC/MC: (MH)=836; (M+Na) + =860
Example 12
Preparation of N α -[-(2-amide-2-oxoethoxy) acetic acid]-Ala-Ala-Asn-PABC-mitomycin [12]
[0112] Ala-Ala-Asn-PANC-mitomycin [7] (295 mg, 0.4 mmoles) in THF/DMF (4/0.5 mL) was treated with 1,4-dioxane-2,6-dione (70 mg, 0.6 mmoles) and DIEA (60 mg, 0.5 mmoles) at room temperature for 2 hours. Ethyl ether (10 mL) was added slowly and the mixture was stirred for 30 min. Solvent was removed and the residue was triturated and sonicated in 1% acetic acid in ethyl acetate. Solid was collected by filtration, rinsed thoroughly with ethyl acetate and dried in vacuum to give a dark color product (276 mg, 80% yield).
[0113] LC/MC: (M-H) − =854
Example 13
Preparation of N α -[-((2-amide-2-oxoethoxy)(methyl) amino) acetic acid]-Ala-Ala-Asn-PABC-mitomycin [13]
[0114] Ala-Ala-Asn-PANC-mitomycin [7] (295 mg, 0.4 mmoles) in THF/DMF (4/0.5 mL) was treated with 4-methylmorpholine-2,6-dione (77 mg, 0.6 mmoles) and DIEA (130 mg, 1.0 mmole) at room temperature for 2 hours. Ethyl ether (10 mL) was added slowly and the mixture was stirred for 30 min. Solvent was removed and the residue was triturated and sonicated in 1% acetic acid in ethyl acetate. Solid was collected by filtration, rinsed thoroughly with ethyl acetate and dried in vacuum to give a dark color product (339 mg, 97% yield).
[0115] LC/MS: (M-H) − =867
Example 14
Preparation of N α -Fmoc-Asn(N-trityl)-PAB-OH [14]
[0116] A solution of N α -Fmoc-Asn(N-trityl) ((1.49 g, 2.5 mmoles), p-aminobenzyl alcohol (0.37 g, 3.0 mmoles) and EEDQ (0.74 g, 3 mmoles) in THF (50 mL) were stirred at room temperature overnight. Additional amount of EEDQ (0.25 g, 1.0 mmole) was added and stirred for another 6 hours. Reaction solution was diluted with ethyl acetate (300 mL) washed with 0.1 N HCl three times and dried over Na 2 SO 4 . The acetate solution was filtered through a short silica plug, rinsed with ethyl acetate and concentrated to dryness. The residue was triturated in ethyl ether, filtered, rinsed with ethyl ether and dried in vacuum to give a white solid (1.65 g, 93% yield).
[0117] LC/MS: (MH) + =702
Example 15
Preparation of Asn(N-trityl)-PAB-OH [15]
[0118] To a solution of N α -Fmoc-Asn(N-trityl)-PAB-OH [14] (1.6 g, 2.28 mmoles) in CH 2 Cl 2 (50 mL) was added DBU (1 mL). The reaction solution was stirred for 15 min. The reaction solution was diluted with CH 2 Cl 2 (200 mL), washed with brine twice and dried over Na 2 SO 4 , filtered and concentrated to dryness. The residue was triturated in hexane/ethyl ether (1/1). Solid was collected by filtration, rinsed with ethyl ether and dried in vacuum to give a white product (1.1 g, 100% yield).
[0119] LC/MS: (MH) + =480
Example 16
Preparation of N α -Fmoc-Ala-Ala-Asn(N-trityl)-PAB-OH [16]
[0120] A solution of Asn(N-trityl)-PAB-OH [15] (0.72 g, 1.5 mmoles), N α -Fmoc-Ala-Ala [1](0.57 g, 1.5 mmol), PyBop (0.94 g, 1.8 mmoles) and DIEA (1.17 g, 9.0 mmoles) in NMP (20 mL) was stirred at room temperature for 1 hour. To the above reaction, 5% citric acid aqueous solution (150 mL) was added slowly at ice-water temperature and stirred for 2 hours. The precipitate was collected by filtration and rinsed with 5% citric acid solution, followed by de-salt water. Solid was re-suspended in aqueous NaHCO 3 solution, triturated, filtered, rinsed with de-salt water and dried in vacuum over KOH to give a white product (1.1 g, 87% yield).
[0121] LC/MS: (MH) + =845
Example 17
Preparation of N α -Fmoc-Ala-Ala-Asn(N-trityl)-PABC-PNP[17]
[0122] A reaction solution of N α -Fmoc-Ala-Ala-Asn(N-trityl)-PAB-OH [16](1.1 g, 1.3 mmol), p-nitrophenyl chloroforrnate (0.31 g, 1.6 mmoles) and pyridine (0.13 g, 1.6 mmoles) in dry THF was stirred at room temperature overnight. Additional amount of p-nitrophenyl chloroforrnate (0.2 g, 1.0 mmole) and pyridine (0.08 g, 1.0 mmole) were added and stirred for another 4 hours. The above solution was diluted with ethyl acetate (300 mL) and washed with 5% citric acid solution (3×100 mL), followed by brine, dried over Na 2 SO 4 , filtered and concentrated to dryness. Residue was triturated in ethyl ether, filtered, rinsed with ethyl ether and dried in vacuum to give an off-white product (1.1 g, 83% yield).
[0123] LC/MS: (MH) + =1010
Example 18
Preparation of N α -Fmoc-Ala-Ala-Asn-PABC-PNP [18]
[0124] A solution of N α -Fmoc-Ala-Ala-Asn(N-trityl)-PABC-PNP[17] (1.0 g, 1 mmole) and TIPS (2.5 mL) in TFA/CH 2 Cl 2 (6/24 mL) was stirred at room temperature for 2 hours. To the above reaction solution, ethyl ether (150 mL) was added slowly and the suspension was stirred for 1 hour. Precipitate was collected by filtration and rinsed with ethyl ether. The solid was triturated in ethyl acetate, filtered, rinsed with ethyl acetate and dried in vacuum to give an off-white product (0.75 g, 97% yield).
[0125] LC/MS: (MH) + =767
Example 19
Preparation of N α -Fmoc-Ala-Ala-Asn-PABC-doxorubicin[19]
[0126] A reaction solution of N α -Fmoc-Ala-Ala-Asn-PABC-PNP[18] (383 mg, 0.5 mmoles), doxorubicin hydrochloride salt (348 mg, 0.6 mmoles), HOBT (202 mg, 1.5 mmoles) and DIEA (325 mg, 2.5 mmoles) in dry DMF (5 mL) was stirred in dark place overnight. To the above solution, 5% citric acid (100 mL) was added slowly at ice-water temperature and stirred for 1 hour. Precipitate was collected by filtration, rinsed with 5% citric acid, followed by de-salt water. The solid was re-suspended in aqueous NaHCO 3 solution and stirred for 30 min. Solid was collected, rinsed thoroughly with NaHCO 3 solution, followed by de-salt water. The solid was re-suspended in isopropanol, 10% methanol/ethyl acetate, triturated, filtered and dried in vacuum to give a dark red product (550 mg, 94% yield)
[0127] LC/MS: (MH) + =1171
Example 20
Preparation of Ala-Ala-Asn-PABC-doxorubicin [20]
[0128] A solution of N α -Fmoc-Ala-Ala-Asn-PABC-doxorubicin[19] (500 mg, 0.42 mmoles) in 20% morpholine/NMP (5 mL) was stirred for 1 hour. To the above reaction solution, ethyl ether (50 mL) was added slowly and the resulted suspension was stirred for 30 min. The ethyl ether was poured off (repeated three times). The residue was triturated in ethyl acetate, 20% methanol/ethyl acetate. Solid was collected by filtration and dried in vacuum. The solid was re-suspended in water, sonicated, filtered and dried in vacuum over KOH to give a dark red product (320 mg, 80% yield).
[0129] LC/MC: (MH) + =949
[0130] Similar methods for the preparation of Example 8, 12 and 13 were used for the preparation of Example of 21, 22 and 23 from compound [20].
Example 21
N α -succinamic acid-Ala-Ala-Asn-PABC-doxorubicin [21]
[0131] LC/MS: (MH) + =1049
Example 22
N α -[-(2-amide-2-oxoethoxy) acetic acid]-Ala-Ala-Asn-PABC-doxorubicin [22]
[0132] LC/MS: (MH) + =1065
Example 23
N α -[-((2-amide-2-oxoethoxy)(methyl) amino) acetic acid]-Ala-Ala-Asn-PABC-doxorubicin [23]
[0133] LC/MS: (MH) + =1078
Example 24
Preparation N α -Fmoc-Asn-PABC-camptothecin[24]
[0134] To a suspension of camptothecin (348 mg, 1 mmole) and DAMP (366 mg, 3 mmoles) in dry CH 2 Cl 2 (20 mL), triphosgene (100 mg, 0.33 mmoles) was added at ice-water temperature with stirring. After 20 min., a suspension of N α -Fmoc-Asn-PAB-OH [2] (459 mg, 1 mmole) in dry CH 2 Cl 2 (10 mL) was added to above reaction mixture and stirred overnight at room temperature. To the resulting reaction mixture, p-nitrophenyl chloroforrnate (100 mg, 0.5 mmoles) was added, followed by additional amount of DAMP (60 mg, 0.5 mmoles), and the reaction mixture was stirred for another 4 hours. After concentration, the resulting residue was triturated with 25% CH 2 Cl 2 /ethyl acetate, filtered, rinsed with 25% CH 2 Cl 2 /ethyl acetate and dried in vacuum. Solid was suspended in aqueous NaHCO 3 , sonicated, filtered, rinsed thoroughly with aqueous NaHCO 3 , followed by 5% citric acid, de-salt water and dried in vacuum over KOH to give a off-yellow product (763 mg, 91% yield).
[0135] LC/MS: (MH) + =834
Example 25
Preparation of Asn-PABC-camptothecin[25]
[0136] A solution of N α -Fmoc-Asn-PABC-camptothecin[24] (500 mg, 0.6 mmoles) in 2% DBU/CH 2 Cl 2 (15 mL) was stirred for 20 min. Ethyl ether (80 mL) was added slowly into above reaction solution and stirred for 30 min. Precipitate was triturated, collected by filtration and rinsed thoroughly with ethyl ether. Solid was re-triturated in 20% CH 2 Cl 2 /ethyl acetate, filtered and dried. The solid was re-suspended in aqueous NaHCO 3 , triturated, filtered, rinsed with de-salt water and dried in vacuum over KOH to give an off-yellow product (295 mg, 80% yield).
[0137] LC/MS: (MH) + =612
Example 26
Preparation of N α -Fmoc-Ala-Ala-Asn-PABC-camptothecin[26]
[0138] A solution of H 2 N-Asn-PABC-camptothecin[25] (244 mg, 0.4 mmoles), N α -Ala-Ala [1] (190 mg, 0.5 mmoles), PyBop (260 mg, 0.5 mmoles) and DIEA (325 mg, 2.5 mmoles) in NMP (5 mL) was stirred for 1 hour. To the above reaction solution, 5% citric acid (50 mL) was added slowly and the resulted mixture was stirred for 30 min. Precipitate was collected by filtration, rinsed with 5% citric acid, followed by de-salt water and dried in vacuum over KOH. The solid was triturated in 15% CH 2 Cl 2 /ethyl acetate, sonicated, filtered and dried to give a gray color product (274 mg, 70% yield).
[0139] LC/MS: (MH) + =976
Example 27
Preparation of Ala-Ala-Asn-PABC-camptothecin[27]
[0140] A solution of N α -Fmoc-Ala-Ala-Asn-PABC-camptothecin[26] (487 mg, 0.5 mmoles) in 2% DBU/CH 2 Cl 2 (10 mL) was stirred for 10 min. To the above reaction solution, ethyl ether (50 mL) was added slowly and stirred for 30 min. Precipitate was collected, rinsed with ether. The solid was suspended in 20% CH 2 Cl 2 /ethyl acetate, triturated, filtered, rinsed with ethyl acetate and dried to give a gray color product (290 mg, 77% yield).
[0141] LC/MS: (MH) + =754
[0142] Similar methods for the preparation of Example 8, 12 and 13 were used for the preparation of Example of 28, 29 and 30 from compound [27].
Example 28
N α -succinamic acid-Ala-Ala-Asn-PABC-camptothecin[28]
[0143] LC/MS: (MH) + =854
Example 29
N α -[-(2-amide-2-oxoethoxy) acetic acid]-Ala-Ala-Asn-PABC-camptothecin [29]
[0144] LC/MS: (MH) + =870
Example 30
N α -[-((2-amide-2-oxoethoxy)(methyl) amino) acetic acid]-Ala-Ala-Asn-PABC-camptothecin [30]
[0145] LC/MS: (MH) + =883
Example 31
Preparation of N 1 -Ala-Ala-Asn-PABC-mitomycin, N 4 -Ala-Ala-Asn-PABC-doxorubicin-succinamide [31]
[0146] A solution of N α -succinamic acid-Ala-Ala-Asn-PABC-mitomycin [8] (85 mg, 0.1 mmole), Ala-Ala-Asn-PABC-doxorubicin [20] (104 mg, 0.11 mmoles), PyBop (62 mg, 0.12 mmoles) and DIEA (78 mg, 0.6 mmoles) in NMP (2 mL) was stirred for 1 hour. Ethyl ether (20 mL) was added and the resulted mixture was stirred and sonicated. The ether was poured off (repeated twice) and the residue was triturated in methanol, filtered and dried to give a dark color product (100 mg, 57% yield)
[0147] LC/MS: (MH) + =1770
Example 32
Preparation of N 1 -Ala-Ala-Asn-PABC-mitomycin, N 5 -Ala-Ala-Asn-PABC-doxorubicin-bis(O α )-acetamide [32]
[0148] Similar methods for the preparation of Example 31 were used for the preparation of Example 32, from compound [20] and compound [12].
[0149] LC/MS: (MH) + =1786
Example 33
Preparation of N 1 -Ala-Ala-Asn-PABC-mitomycin, N 5 -Ala-Ala-Asn-PABC-doxorubicin-bis(N α -methyl)-acetamide [33]
[0150] Similar methods for the preparation of Example 31 were used for the preparation of Example 33, from compound [20] and compound [13].
[0151] LC/MS: (MH) + =1799
Example 34
Preparation of N 1 -Ala-Ala-Asn-PABC-mitomycin, N 4 -Ala-Ala-Asn-PABC-camptothecin-succinamide [34]
[0152] Similar methods for the preparation of Example 31 were used for the preparation of Example 34, from compound [27] and compound [8].
[0153] LC/MS: (MH) + =1575
Example 35
Preparation of N 1 -Ala-Ala-Asn-PABC-mitomycin, N 5 -Ala-Ala-Asn-PABC-camptothecin-bis(O α )-acetamide [35]
[0154] Similar methods for the preparation of Example 31 were used for the preparation of Example 34, from compound [27] and compound [12].
[0155] LC/MS: (MH) + =1591
Example 36
Preparation of N 1 -Ala-Ala-Asn-PABC-mitomycin, N 5 -Ala-Ala-Asn-PABC-camptothecin-bis(N α -methyl)-acetamide [36]
[0156] Similar methods for the preparation of Example 31 were used for the preparation of Example 34, from compound [27] and compound [13].
[0157] LC/MS: (MH) + =1604
Abbreviations Used in the Examples
[0158] DCC=dicyclohexylcarbodiimide
DCM=dichloromethane
DCU=dicyclohexylurea
DIEA=diisopropylethylamine
DMA=dimethylacetamide
DMEM=Dulbecco's modified Eagle medium
DMF=N,N-dimethylformamide
[0159] DMSO=dimethylsulfoxide
EDC=1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide
EDTA=N,N′,N″, N′″, N″″-ethylenediaminetetraacetic acid
FBS=fetal bovine serum
Fmoc=fluorenylmethoxycarbamoyl
HATU=1-[Bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium-3-oxid hexafluorophosphate
HOBT=N-Hydroxybenzotriazole
[0160] HPLC=high pressure liquid chromatography
IR=infrared spectroscopy
LC/MS=liquid chromatography/mass spectrometry
MS=mass spectrometry
MTD=maximum tolerated dose
NMP=N-methylpyrrolidinone
[0161] NMR=nuclear magnetic resonance
PABC=p-aminobenzylcarbamoyl
PBS=phosphate buffered saline
Py=pyridine
QW=per week
TCA=trichloroacetic acid
Tr=trityl, triphenylmethyl
UV/VIS=ultraviolet/visible spectroscopy
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Peptide-drug conjugates comprising p-aminobenzyl carbamoyl or p-aminobenzolyl carbonate self-immolating linkers are disclosed. The peptide-drug conjugates comprise a peptide moiety that can be cleaved by cellular proteases, bound to the self-immolating linker, which linker is bound to a cytotoxic drug moiety. Upon cleavage of the peptide moiety, the linker self-immolates, releasing the cytotoxic drug in active form. Dimeric structures of the peptide drug conjugates comprising two molecules of cytotoxic drug per conjugate are also disclosed.
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BACKGROUND OF THE INVENTION
This invention relates to an apparatus for regularly laying hexahedral articles in predetermined positions, and more particularly to an automatic article laying apparatus suited for automatically and continuously lining a furnace by geometrically laying hexahedral refractories of different sizes.
With the recent remarkable technological innovation, industrial furnaces have grown larger and more complex. They have introduced more continuous-operation features, and come to be operated under severer conditions. Under such circumstances, many new furnaces are built and many old furnaces relined. The furnaces cannot be constructed without refractory lining that is accomplished in two ways. A traditional method comprises laying refractory bricks in a geometrical pattern. A more modern method, developed to cope with the recent manpower shortage, uses castable refractories. General preference is given to the brick lining because of its higher reliability.
Conventionally, the brick lining work (hereinafter called brick laying) has been done by manually laying refractory bricks, one on another, that have been carried into a furnace in various ways. But this brick laying is a hard muscular labor. With high temperatures and dust, the work environment is unfavorable. In addition, the unstable demand for this work lowers the personnel efficiency. For these reasons, mechanizing and labor-saving measures have been studied. Some attempts have been made for the development of brick laying apparatus. But none of such attempts have been put to practical use. A brick laying machine should be capable of conveying and laying bricks automatically. It has to convey a brick to the laying position in good condition, put it in place smoothly without tumbling or changing its posture, and accomplish automatic brick laying. No perfect machines have been commercialized.
SUMMARY OF THE INVENTION
This invention has solved the aforementioned problems.
An object of this invention is to provide an automatic article-laying apparatus for placing hexahedral articles in an exactly geometrical pattern.
Another object of this invention is to provide an automatic article-laying apparatus that operates rapidly, stops with high accuracy, and greatly reduces the laying time per article.
Still another object of this invention is to provide an automatic article-laying apparatus that can convey articles stably, being furnished with the dual function of laying and conveying.
Yet another object of this invention is to provide an automatic article-laying apparatus equipped with compact transporting and housing means.
For achieving these objects, an automatic article-laying apparatus according to this invention is positioned at the terminal end of a horizontally rotatable conveyor. The apparatus comprises a horizontally rotatable roller conveyor adapted to be placed adjacent to the first-mentioned conveyor and carrying an article holder that projects sidewards, below the plane on which articles are conveyed, so as to contact the side of the previously laid article, a hydraulic drive to horizontally rotate the roller conveyor, a traversing plate that is positioned close and parallel to the roller conveyor and pushes an article away from the roller conveyor, at right angles to the direction of conveyor travel and toward the article holder, and a reciprocating head that extends along the roller conveyor and behind the article holder and pushes forward the article delivered from the roller conveyor in the direction of conveyor travel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic sectional side elevation showing a furnace lining unit equipped with an automatic article-laying apparatus that embodies the principle of this invention, together with the cross-section of a basic oxygen furnace.
FIG. 2 is a plan view of the automatic article-laying apparatus according to this invention.
FIG. 3 is a side elevation of the apparatus shown in FIG. 2.
FIGS. 4 through 7 are plan views illustrating the operation of the apparatus. FIG. 4 shows a condition in which a refractory brick has been conveyed close to its laying position. FIG. 5 shows a condition in which the refractory brick is pushed sideward. FIG. 6 shows a condition in which a rotatable roller conveyor is withdrawn. FIG. 7 shows a condition in which the refractory brick is pushed forward into position.
FIG. 8 shows a hydraulic circuit of drive means used in the apparatus of this invention.
FIG. 9 is a wiring diagram showing the connection between solenoids of solenoid valves and contacts of electromagnetic relays shown in the aforementioned hydraulic circuit.
FIG. 10 is a wiring diagram showing the connection between proximity switches and coils of electromagnetic relays used in the drive means.
FIG. 11 shows a sequence circuit used for the automatic operation of the apparatus.
FIG. 12 is a flow chart of the automatic operation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
An automatic article-laying apparatus of this invention is suited for use in laying hexahedral articles, especially refractory bricks, in an exactly geometrical pattern. Now details of this invention will be described by reference to a lining unit for basic oxygen furnaces.
As shown in FIG. 1, a furnace lining unit 11 has a tower buggy 12 that runs on rails 8 fixed on the floor 8 and can be positioned right above a basic oxygen furnace 1. The tower buggy 12 carries a tower 13 that moves up and down and contains a vertical conveyor 14 operated by drive means 15. A wire 18 whose end is fixed to a wire drum 19 is slung over a pulley 16 on the tower buggy 12 and a pulley 17 on the tower 13. Rotated by a motor 20, the wire drum 19 either takes up or pays off the wire 18, thereby raising or lowering the tower 13. A rotating carriage 21, rotatably fitted to the bottom of the tower 13, carries a distributor 22. An expandable conveyor 23 extends from the distributor 22.
The rotary carriage 21 of the above-described furnace lining unit 11 is put in the furnace 1. By moving the tower 13, the rotating carriage 21 is positioned at a height where brick is to be lined. On the tower buggy 12, refractory bricks 3 are transferred, one at a time, from a feeder 24 to the vertical conveyor 14, which carries the bricks down to the distributor 22. Thence, the brick 3 is carried to the remotest end of the expandable conveyor 23, where an automatic laying apparatus 31 of this invention receives it for laying in position.
Now the automatic laying apparatus according to this invention will be described by reference to FIGS. 2 and 3.
A stand 32 is placed under the expandable conveyor 23. A left bracket 33 and a right bracket 34 (looking in the downstream of brick travel) project forward from near the front top end of the stand 32. The front end of the left bracket 33 fixes to a base 35 that comprises base plates 36 and 37. The base plates 36 and 37 are joined together by a metal hinge 38, so that the base plate 37 can be manually turned upward, with respect to the base plate 36, from horizontal to vertical. A bearing member 41 fixedly projects forward from the front end of the stand 32. The bearing member 41 supports a rotating shaft 43 fixed to a rotating bracket 42.
A rotatable roller conveyor 51 lies before the front end of the expandable conveyor 23. A shaft 53 fixes through a coupling member 52 to the rear end of the rotatable roller conveyor 51. The shaft 53 is rotatably supported by a bearing 44 fixed on the top of the front end of the rotating bracket 42. A hydraulic cylinder 47 is reciprocatably fitted through a trunnion 46 to a support 45 on the rotating bracket 42. The upper end of a rod 48 of the hydraulic cylinder 47 connects through a pin 49 to one end of an arm 50 so that both can rotate freely. The other end of the arm 50 fixes to the shaft 53. Accordingly, the rotatable roller conveyor 51 turns up and down with the motion of the hydraulic cylinder 47, so that the conveyor 51 can be turned downward until it stands perpendicular to the expandable conveyor 23.
The rotatable roller conveyor 51 comprises a frame 54 and a number of rollers 55 rotatably set therein. The rollers 55 are so arranged as to form a plane that dips forward slightly. Therefore, the refractory brick 3 moves forward by gravity. A stopper 56 is provided at the front end of the rotatable roller conveyor 51. An article holder 57 projects rightward from near the front end, at the same level or slightly below the plane of the rollers 55.
A hydraulic cylinder 64 is reciprocatably fitted through a trunnion 62 to a support 61 on the front end of the left bracket 33. The remotest end of a rod 64 of the hydraulic cylinder 63 connects through a pin 65 to the rotating bracket 42. Therefore, the reciprocation of the hydraulic cylinder 63 turns the rotatable roller conveyor 51 from side to side, integrally with the rotating bracket 42.
A slide plate 71 is placed on the front part of the foremost base plate 37 of the base 35, with a pin 72 fastening them together. A hydraulic cylinder 83 is reciprocatably fitted through a trunnion 82 to a support 81 on the base plate 37. The remotest end of a rod 84 of the hydraulic cylinder 83 connects through a pin 85 to the end of the slide plate 71 opposite to the pin 72. Therefore, the reciprocation of the hydraulic cylinder 83 turns the slide plate 71 about the pin 72. The slide plate 71 carries a hydraulic cylinder 92, extending perpendicular to the direction of conveyor travel, on a support 91. The remotest end of a rod 93 of the hydraulic cylinder 92 connects through a pin 94 to a traversing plate 95.
The right bracket 34 carries a hydraulic cylinder 102, which projects forward, on a support 101. The remotest end of a rod 103 of the hydraulic cylinder 102 connects to a reciprocating head 104.
Next, the operation of the above-described automatic article-laying apparatus will be described by reference to FIGS. 4 through 7.
As shown in FIG. 4, the brick 3, carried by the expandable conveyor 23 onto the rotatable roller conveyor 51, stops at the stopper 56. Driven by the hydraulic cylinder 92, the traversing plate 95 pushes the brick 3 rightward until it comes in contact with the previously laid brick 4. Then, as shown in FIG. 5, the brick 3 is held between the traversing plate 95 extended over the rotatable roller conveyor 57 and the previously laid brick 4.
Then, as seen in FIG. 6, the hydraulic cylinder 63 is operated to move the rotatable roller conveyor 51 leftward or opposite to the direction in which the brick 3 is pressed. At the same time, the pressing force is released so that the brick 3 drops by gravity to the level one course below. When the brick 3 has been thus placed in position, the rod 64 of the hydraulic cylinder 63 extends to bring the article holder 57 on the rotatable roller conveyor 51 in contact with the side of the brick 3, so that the sides of the bricks 3 and 4 stick fast to each other. On further extending the rod 64, the expandable conveyor 23, which projects from the rotating carriage 21 so as to be rotatable about the tower 13, shifts its position by the width of the brick 3, or from the position in FIG. 6 to that in FIG. 7. Finally, the hydraulic cylinder 102 pushes forward the reciprocating head 104 to press the brick 3 into position, as shown in FIG. 7. During this final process, the article holder 57 presses the brick 3 against the previously laid brick 4, thereby permitting clearance-free, tight laying.
Next, automatic control of this automatic article-laying apparatus will be described.
FIG. 8 is a circuit diagram of hydraulic drive means containing said hydraulic cylinders. A hydraulic supply 111 comprises an oil tank 112 and a pump 114 driven by a motor 113. The hydraulic cylinder 63 to rotate the rotatable roller conveyor 51, the one 92 to push the brick sideward, and the one 102 to push the brick forward connect to solenoid valves 67, 97 and 107, respectively. These cylinders are of the double-acting type. A hydraulic fluid is supplied from the pump 114 through the solenoid valves to either the piston side or the rod side of the hydraulic cylinders and returned to the oil tank 112 from either the piston side or the rod side thereof, depending on the direction of operation of each cylinder.
A solenoid valve 117 is provided between a line 115 connecting to P-ports of the solenoid valves 67 and 97 and a line 116 connecting to T-ports thereof.
When stopping the automatic article-laying apparatus, the solenoid valve 117 is switched to return the hydraulic fluid from the pump 114 to the tank 112 so that no hydraulic pressure works on the solenoid valves 67 and 97.
As shown in FIG. 9, solenoids 68, 98 and 108 of the solenoid valves 67, 97 and 107 connect to contacts 2FD, 2FE, 2RD and 2RE of relays 2F and 2R, contacts 1FD, 1FE, 1RD and 1RE of relays 1F and 1R, and contacts 3FD, 3FE, 3RD and 3RE of relays 3F and 3R, respectively. Each relay will be found in FIG. 11 described later.
FIG. 10 is a circuit diagram of proximity switches for detecting operating positions. A relay PHX connects to a photoelectric switch PH (see FIG. 2) that is fitted close to the front end of the rotatable roller onveyor 51 to detect the arrival of the brick 3. A relay N2X connects to a proximity switch N2 that is fitted to the base 35, adjacent to the hydraulic cylinder rod 63, to detect the limit position of the rotatable roller conveyor 51 that has withdrawn (or turned to the left in FIG. 2). A relay N1X connects to a proximity switch N1 that is fitted to the expandable conveyor 23, adjacent to the rotating bracket 42, to detect the limit position of the rotatable roller conveyor 51 that has advanced to cause the article holder 57 to press the side of the brick 3. A relay N3X connects to a proximity switch N3 that is fitted to the slide plate 71, adjacent to the hydraulic cylinder 93, to detect a condition in which the hydraulic cylinder 92 has brought the brick 3 in contact with the previously laid brick 4. A relay PSX connects to a pressure switch PS that is connected to the hydraulic cylinder 102, as shown in FIG. 8, to detect a condition in which the brick 3 has been pushed to the longitudinal limit.
Now, automatic operation of this apparatus will be described by reference to a sequence circuit in FIG. 11 and a flow chart in FIG. 12. A manual switch PB1 in FIG. 11 stops the apparatus. Manual switches PB2 and PB3 permit moving the brick sideward. Manual switches PB4 and PB5 permit turning the rotatable roller conveyor 51. Manual switches PB6 and PB7 permit pushing the brick longitudinally.
When the photoelectric switch PH detects the arrival of the brick 3, a contact PHXA of the relay PHX closes, whereupon the relay 1F acts to close contacts 1FA and 1FB of a line L1, together with the contacts 1FD and 1FE in FIG. 9. At this time, a contact 1FC of a line L2 opens. This energizes the solenoid 98 in FIG. 8 to actuate the solenoid valve 97, whereupon the hydraulic cylinder 97 operates to push the brick 3 sideward.
When the brick 3 has been pushed sideward as shown in FIG. 5, the proximity switch N3 detects it, whereupon the relay N3X operates to open a contact N3XA of the line L1 and closes a contact N3XB of a line L7. Then, the relay 2R of the line L7 operates to close contacts 2RA and 2RB, open a contact 2RC of a line 6, and close the contacts 2RD and 2RE in FIG. 9. Then, the solenoid 68 becomes energized to actuate the solenoid valve 67. This drives the hydraulic cylinder 63 to withdrawn the rotatable roller conveyor 51, so that the brick 3 drops by gravity to the level one course below. On resetting the traversing circuit, the contacts 1FA, 1FB, 1FD and 1FE open and the contact 1FC closes.
When the rotatable roller conveyor 51 has withdrawn to the position shown in FIG. 6, the proximity switch N2 detects it, whereupon the relay N2X operates to close a contact N2XA of a line L8. Then, a relay 4Y operates to close a contact 4YA of the line L8. At the same time, a contact N2XB of the line L7 opens, and a contact 4YB of a line L3 and a contact 2RC of the line L6 close, thereby resetting the withdrawal circuit for the rotatable roller conveyor 51. A relay 2FX of a line L5 operates to close a contact 2FXA of the line L5 and a contact 2FXB of the line L6, thereby actuating the relay 2F. Then, the contacts 2FD and 2FE in FIG. 9 close, whereby the solenoid 68 becomes energized to actuate the solenoid valve 67. Consequently, the hydraulic cylinder 63 drives the traversing plate 57 so that the brick 3 is pressed against the side of the previously laid brick. Then, the expandable conveyor 23 moves by the width of the brick 3 into the position shown in FIG. 7. At the same time, the contact 4YB of the line L3 closes. Then, a time relay 4XT of a line L4 operates, together with a relay 4X of the line L3, thereby closing a contact 4XA of the line L4 and a contact 4XB of the line L2 and opening a contact 4XC of the line L7. The relay 1R operates to close a contact 1RA and open a contact 1RB of the line L1. Then, the contacts 1RD and 1RE in FIG. 9 become closed and the contacts 1FD and 1FE opened. Consequently, the hydraulic cylinder 92 is driven until a contact 4XTA of the time relay 4XT opens, whereupon the rod 93 withdraws to its original position.
When the expandable conveyor 23 has turned to the position shown in FIG. 7, the proximity switch N1 detects it and the relay N1X operates to open a contact N1XA of a line L5. This, in turn, opens the contacts 2FXA and 2FXB and closes the contact 2FA, thus stopping the rotation of the expandable conveyor 23 by the hydraulic cylinder 63. At the same time, a contact N1B of a line L9 closes, and the relay 3F of the line L9 operates to close contacts 3FA and 3FB of the line L9. A contact 4YC of the line L9 has been closed by the aforesaid operation of the relay 4Y of the line L8. A contact 3FF of the line L1 and a contact 3FC of a line 10 open. Then, the contacts 3FD and 3FE in FIG. 9 close, whereupon the solenoid 108 becomes energized to actuate the solenoid valve 107. This drives the hydraulic cylinder 102 to push the brick 3 longitudinally.
When the brick 3 comes to a standstill in position, the pressure in the hydraulic cylinder 102 rises to actuate the pressure switch PS, which in turn actuates the relay PSX in FIG. 10. THis opens a contact PSXA of the line L9, closes a contact PSXB of a line 14, and actuates a relay 5Z to close a contact 5ZA of a line L15. Then, a time relay 5ZT operates to open a contact 5ZTA of the line L9 and close a contact 5ZTB of a line L12 after a predetermined time has elapsed. Consequently, the contacts 3FD and 3FE in FIG. 9 open to stop the operation of the hydraulic cylinder 102 and reset the circuit for the longitudinal push. When the contact 5ZTB closes as described above, a relay 5Y of the line L12 operates to close a contact 5YA of a line L13 and a contact 5YB of the line L10, whereupon a time relay 5YT of the line L13 operates. Until a contact 5YTA of the time relay 5YT opens, the relay 3R of the line L10 and a relay 3RX of a line L11 operate to close a contact 3RA of the line L10 and open a contact 3RB of the line L9 and a contact 3RXa of the line L14. Then, the contacts 3FD and 3FE in FIG. 9 open and the contacts 3RD and 3RE close, whereby the solenoid 108 becomes energized to actuate the solenoid valve 107. Consequently, the rod 103 of the hydraulic cylinder 102 returns to the original position while the contact 5YTA remains closed. At this time, a contact 3RC of the line L8 opens.
The brick laying cycle according to this invention ends when the brick has been pushed longitudinally, thus permitting a smooth transition to the laying of the next brick. This feature facilitates a continuous, automatic laying operation. Particularly effective is a design that permits stably pushing sideward bricks of different sizes. This design consists in traversing means that pushes the brick in the vicinity of its center of gravity. The embodiment described is adapted to achieve good results by turning the slide plate 71 about the pin 72 by the hydraulic cylinder 83 so that the traversing plate 95 be adjusted to the center of gravity of the brick.
The hinged rotatable roller conveyor 51 and the base 37 carrying the hydraulic cylinders 83 and 92 facilitate the housing of the apparatus.
Although this specification has described an application to brick laying, the apparatus of this invention can be used also for placing boxes or box-like articles in position.
Hydraulic cylinders are used for the traversing means, rotating means, reciprocating means, transverse positioning means and collapsing means of the above-described embodiment. But other driving means with similar functions can be used, too.
As will be understood, fromt he above, this invention enables bricks and other articles to be placed in position in a very short time. It permits automatic brick laying with quick operation, high stop accuracy and stable brick transfer. In addition, the apparatus of this invention is compact enogugh to facilitate its transportation and housing.
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An automatic article-laying apparatus is positioned at the terminal end of a horizontally rotatable conveyor. The apparatus comprises a rotatable roller conveyor, a hydraulic drive to horizontally rotate the roller conveyor, a traversing plate, and a reciprocating head. Placed adjacent to the first-mentioned conveyor, the roller conveyor is horizontally rotatable and carries an article holder that projects sidewards, below the plane on which articles are conveyed, so as to contact the side of the previously laid article. Positioned close and parallel to the roller conveyor, the traversing plate pushes an article away from the roller conveyor, at right angles to the direction of conveyor travel and toward the article holder. Extending along the roller conveyor and behind the article holder, the reciprocating head pushes forward the article delivered from the roller conveyor in the direction of conveyor travel. With this apparatus, hexahedral articles can be laid in an exactly geometrical pattern.
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BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a pattern selecting device of a sewing machine, and more particularly to a device for enabling a sewing machine operator to select a desired one of the pattern cams in any angular position of a main drive shaft of the sewing machine. More precisely according to the invention, a cam follower may be manually disengaged from one of the pattern cams and engaged to a newly selected pattern cam in any one of the plurality of angular positions of the main drive shaft of the sewing machine, that is, even if a machine needle remains in a fabric to be sewn when the sewing machine is standstill. Further the manually disengaged cam follower may be automatically engaged with the newly selected pattern cam when the sewing machine is driven and the main drive shaft comes to a predetermined angular range in which the machine needle is located above the fabric.
A sewing machine having a conventional pattern cam selecting device generally requires a considerable amount of manual force each time in order to disengage a cam follower from one of the pattern cams in the pattern cam selecting range because the cam follower is normally spring-biased toward the pattern cams. To eliminate such a problem, some sewing machines have been provided with a mechanism for holding the cam follower in a condition in which it is disengaged from the pattern cam when the cam follower is once disengaged until the follower is brought to the engagement with the newly selected pattern cam. The sewing machine may be further provided with a mechanism which is manually and/or automatically (in the initiation of the drive of the sewing machine) operated to release the cam follower so as to engage the newly selected pattern when the follower was brought to the newly selected pattern cam.
However, in such conventional sewing machines, the disadvantage of the cam follower releasing mechanism resides in preventing the pattern cam selecting operation from being performed within a certain angular range of the main drive shaft of the sewing machine. The cam follower releasing mechansim may include an actuating cam rotated in association with the main drive shaft or a lower drive shaft, a follower lever cooperating with the actuating cam to release the cam follower and a toggle spring for pressing the follower lever against the actuating cam until the cam follower is released from the disengaged position, and then for holding the follower lever at a position spaced from the rotation path of the actuating cam when the cam follower has been released. In this case, the follower lever is moved to a stopper with the force of the toggle spring which is amplified with the inertia of the actuating cam which pushes the follower lever. The follower lever will therefore hit the stopper producing a high impact sound and accordingly giving an adverse influence to the endurance of the associated elements.
SUMMARY OF THE INVENTION
The present invention has been devised to eliminate the above mentioned defects and disadvantages of the prior art.
It is a primary object of the invention to provide a pattern cam selecting device of a sewing machine, which is simple in structure and smooth in operation.
It is another object of the invention to enable a sewing machine operator to select a desired one of pattern cams manually and automatically regardless the angular positions of the main drive shaft of the sewing machine.
It is still another object of the invention to produce the products easily and at lower cost.
The objects of the invention are attained by a pattern selecting device of a sewing machine, which substantially comprises a swingable element which is swingable between a first position in which this element operaties to engage a cam follower to one of stacked pattern cams and a second position in which the swingable element disengages the cam follower from the pattern cam; a mechanism for locking the swingable element in the second position; a clutch mechanism movable between an inoperative position in which the clutch mechanism allows the locking mechanism to lock the swingable element and an operative position in which the clutch mechanism is ready to cause the locking mechanism to unlock the swingable element; a holding mechanism for holding the clutch mechanism in the inoperative position when the swingable element is moved to the second position; a cam rotated in association woth the rotation of a main drive shaft of the sewing machine; and an actuating mechanism including a follower element, the actuating mechanism being normally held in an inoperative position by the locking mechanism, in which position the follower element is located out of the rotation path of the cam, the actuating mechanism being released by the locking mechanism into an operative position as the locking mechansim moves to lock the swingable element in the second position, while the follower element is allowed to come into the rotation path of the cam. The clutch mechanism is operated in association with the movement of the actuating mechanism to move to the operative position thereof, the follower element cooperating with the cam as the latter starts to rotate to thereby move the actuating mechanism to the inoperative position. The actuating mechansim in turn operates the clutch mechanism so as to cause the locking mechanism to unlock the swingable element, then the locking mechanism holding the actuating mechanism in said inoperative position.
The other features and advantages of the invention will be apparent from the following description of a preferred embodiment in reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevation view of a device according to the invention;
FIG. 2 is a view of the device taken from arrow A in FIG. 1;
FIG. 3 is an exploded perspective view of the device, with parts removed to show the specific elements of the device;
FIG. 4 is an exploded perspective view of the device, showing substantial elements of the invention; and
FIGS. 5 through 8 are views of the device showing various operational positions of the device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIGS. 1 to 3 it will be seen that a housing 1 of a sewing machine has stacked pattern cams 2 arranged therein, which cams may be rotated at a reduced speed in association with the rotation of a main drive shaft 40. A cam follower 3 having a projection 3a is turnably mounted on a transverse guide shaft 42 which is extended in parallel with the stacked pattern cams 2. A U-shaped frame 41 is swingably mounted on the guide shaft 42. The frame 41 has a vertical wall 41a extended in parallel with the guide shaft 42. The wall 41a has a transverse groove 41b, which is extended in parallel with the guide shaft 42, and the projection 3a of the cam follower 3 engages in the groove 41b. The frame 41 is normally spring-biased in the counterclockwise direction in FIG. 2 to press the cam follower 3 against one of the stacked pattern cams. The frame 41 is formed with an upwardly extended arm 4 which is operatively connected by a transmission rod 5 to a needle bar 43 having a needle 44 attached to the lower end thereof.
Further another U-shaped frame 13 is swingably mounted on the guide shaft 42 and is normally biased by a spring 14 in the counterclockwise direction in FIG. 2. The frame 13 has a downwardly extended follower pawl 13a and a wall 13b (FIG. 3) extended in parallel with the veritcal wall 41a of the frame 41 on the outside of the latter. The wall 13b is partly bent at one end thereof to provide a horizontally extended wall 13c overhanging the swingable frame 41. The overhanging wall 13c has a screw 15 secured thereto. The frame 13 has an auxiliary member 16 secured thereto by screws 17, 18. The member 16 has an inclined cam face 16a terminated with an upper end 16c and an upper cam face 16b.
As shown in FIG. 1, a control shaft 10 is extended through a bracket 45 in parallel with the guide shaft 42 and is rotatable. The control shaft 10 has one end protruded out of the machine housing on the front thereof. A dial 6 is secured to the protruded end of the control shaft 10. A pattern selecting cam 9 is secured to the control shaft 10 by a pin 11 on one side of the bracket 45, and a pattern selecting gear 7 is secured to the control shaft 10 between the bracket 45 and the dial 6. The pattern sleecting gear 7 has a flange 7b (FIG. 3) formed with projections 7a on one face thereof opposite to the inner face of the dial 6 which is formed with a recess 6a. The gear 7 is normally biased toward the dial 6 by a spring 8 arranged between the gear 7 and the bracket 45. The control shaft 10 has a diametrically reduced free end portion 10a which is supported by a part 1a of the machine housing 1. A compression spring 12 is mounted on the reduced free end portion 10a between the shaft 10 and the part 1a of the machine housing 1 and normally biases the control shaft to the left in FIGS. 1 and 2 until the pattern selecting cam 9 is pressed against the bracket 45.
A shorter shaft 19 is extended through the bracket 45 and has a plate 19a secured to one end thereof and an anchor element 21 secured to the other end thereof. The plate 19a is partly located between the dial 6 and the pattern selecting gear 7. A compression spring 20 is mounted on the shaft 19 between the plate 19a and the bracket 45 and normally biases the plate toward the dial 6. A rod 22 is provided which has one end connected to the anchor element 21 and the other end connected to a locking member 26 which will be described below.
Further in reference to FIG. 4, a bracket 24 is fixedly arranged in the machine housing 1. The bracket 24 is provided with a stopper arm 24a and a pivot shaft 24b which are extended transversely of the control shaft 10. The locking member 26 in the form of an elongated plate is at the lower end thereof turnably mounted on the shaft 24b of the bracket 24 and is normally biased in the counterclockwise direction by a spring 25. The locking member 26 has a first arm 26c and a laterally extended second arm 26d formed at the top thereof, and has a laterally extended abutment 26a providing a face 26b. The aforementioned rod 22 has the other end connected to the abutment 26a of the locking member 26. A holding member 27 in the form of an elongated plate is at the lower end thereof turnably mounted on the shaft 24b and is normally biased in the counterclockwise direction by a spring 28 until the front edge 27b thereof is pressed against extended arm 27a formed at the top thereof. An actuating member 29 in the form of an elongated plate is at the lower end thereof turnably mounted on the shaft 24b and is normally biased in the counterclockwise direction by a spring 30. The actuating member 29 has a laterally extended abutment 29a and a laterally extended pin 29b provided at the top thereof and has a laterally extended arm 29c. A clutch member 34 in the form of a lever providing a first arm 34a and a second arm 34b is at the intermediate thereof turnably mounted on the pin 29a of the actuating member 29 and is normally biased in the counterclockwise direction by a coil spring 33 having one end hung to the first arm 34a of the clutch member 34 and the other end anchored to the laterally extended arm 29c of the actuating member 29. The first arm 34a is formed with a stepped portion 34c. A follower member 31 having a lower follower tip 31a is at the upper part thereof turnably mounted on the shaft 24b and is connected to the actuating member 29 by a screw 32, so that the both members may be made integral and operated as an actuating mechanism. A cam 23 having a circumferential portion 23b and a cutout portion 23a is secured to a lower drive shaft 46 which is rotated in association with the main drive shaft 40 of the sewing machine.
With reference to FIGS. 2 through 5 it will be seen that when the pattern cam selecting operation is finished, the follower pawl 13a of the swingable frame 13 engages the diametrically reduced part of the pattern selecting cam 9 and the lower end of the screw 15 of the swingable frame 13 is located above the swingable frame 41. The frame 41, which is normally spring-biased in the counterclockwise direction in FIG. 2, is free to engage the cam follower 3 to a selected one of the stacked pattern cams 2.
In this condition, the second arm 34b of the clutch member 34 engages the upper cam face 16b of the auxiliary member 16 secured to the swingable frame 13, and the arm 27a of the holding member 27 engages the first arm 34a of the clutch member 34, and the first arm 26c of the locking member 26 engages the lower end of the inclined cam face 16a of the auxiliary member 16 while the second arm 26d of the locking member 26 engages the abutment 29a of the actuating member 29 to hold the follower tip 31a of the follower member 31 at a position out of the rotation path of the cam 23, as shown in FIG. 5.
In this condition, the plate 19a (FIG. 3) is pulled to the right against the force of the compression spring 20 by the rod 22 having the right end connected to the abutment 26b of the locking member 26, and therefore the cam selecting gear 7 is pulled out of the engagement with the recess 6a of the dial 6.
When the dial 6 is rotated to select a new pattern cam, the larger diameter portion of the pattern selecting cam 9 engages the follower pawl 13a of the swingable frame 13 and swingingly moves the frame 13 around the guide shaft 42 in the clockwise direction in FIG. 2 against the action of the spring 14. Then the lower end of the screw 15 of the frame 13 engages the frame 41 to turn the latter around the guide shaft 42 in the clockwise direction to thereby disengage the cam follower 3 from the precededly selected pattern cam. As the result, the auxiliary member 16 is moved downwardly and allows the clutch member 34 and the locking member 26 to turn in the counterclockwise direction.
Provided that the dial 6 is rotated to select a new pattern cam when the circumferential portion 23b of the cam 23 happens to be opposite to the follower tip 31a of the follower member 31, as shown in FIG. 5, the actuating mechanism (29, 31) is prevented from turning in the counterclockwise direction around the pivot shaft 24b of the bracket 24 even if the locking member 26 turns in the counterclockwise direction and releases the actuating member 29 as shown in FIG. 7. Therefore the actuating mechanism (29, 31) is held at the initial position as shown. In this case, the clutch member 34 is held in the initial position by the holding member 27 so that the stepped portion 34c of the clutch member will not be in the way of the locking member 26 which is allowed to turn to lock the swingable frame 13 in the cam follower disengaging position.
With reference to FIGS. 3 to 5, it is seen that the locking member 26 is therefore, turned counterclockwise, and the first arm 26c slides along the inclined cam face 16a of the auxiliary member 16 as the latter swings down and engages the top 16c of the inclined cam face 16a to thereby lock the swingable frame 13 in the cam follower disengaging position. Simultaneously the locking member 26 allows the plate 19a to move toward the dial 6 due to the action of the compression spring 20, and accordingly the pattern selecting gear 7 is moved to the dial 6 due to the action of the spring 8 and is connected to the dial 6.
Therefore as the dial 6 is rotated continuously, the disengaged cam follower 3 is moved along the guide shaft 42 and along the stacked pattern cams 2 through a conventional transmission mechanism (not shown). The description of this mechanism is omitted herein because substantially the same mechanism may be referred to in U.S. Pat. No. 4,084,523 of the same applicant.
When the cam follower 3 comes opposite a selected pattern cam, the dial 6 is pushed against the action of the spring 12. Then the end 10a of the control shaft 10 is pressed against the face 26b of the abutment 26a of the locking member 26 and turns the latter in the clockwise direction. Thus the swingable frame 13 is unlocked and released. Then the swingable frame 13 swings back due to the action of the spring 14, and accordingly the frame 41 is allowed to swing back and the cam follower 3 engages the selected pattern cam, and the related members take the positions again as shown in FIG. 5. Thus the swingable frame 13 may be manually unlocked from the locked position.
Now in reference to FIGS. 3, 4 and 6, provided that the dial 6 is rotated for a pattern cam selection when the cutout portion 23a of the cam 23 is opposite to the follower tip 31a of the follower member 31, the locking member 26 moves to lock the swingable frame 13 in the cam follower disengaging position, and subsequently the actuating mechanism (29, 31) is turned in the counterclockwise direction. In this case, the clutch member 34 is moved with respect to the holding member 27 and also may be turned counterclockwise around the pin 29b. Thus the clutch member takes the position ready to disengage the locking member 26 from the top 16c of the inclined cam face 16a when the actuating member (29, 31) is turned in the clockwise direction. Even in this case, the swingable frame 13 may be unlocked by manually pushing the dial 6.
The swingable frame 13 may be unlocked automatically without pushing the dial 6 when the sewing machine starts to be driven. In reference to FIGS. 4 and 5, when the dial 6 is rotated to select a new pattern cam, the swingable frame 13 is turned around the guide shaft 42 (FIG. 2) in the clockwise direction to thereby disengage the cam follower 3 from the precededly selected pattern cam in the way as described above. The auxiliary member 16 is moved together with the swingable frame 13. As the result, the locking member 26 turns counterclockwise and the first arm 26c slides along the inclined cam face 16a and engages the top 16c of the cam face 16a to thereby lock the swingable frame 13 in the cam follower disengaging position. In the meantime the actuating mechanism (29, 31) remains in the initial position as shown because the circumferential portion 23b of the cam 23 is positioned opposite to the follower tip 31a of the follower member 31. In the meantime the clutch member 34 on the actuating member 29 is held in the initial position, as shown, by the holding member 27 against the force of the spring 33 so that the first arm 34a may not be in the way of the locking member 26 moving to lock the swingable frame 13.
Now in reference to FIGS. 4 and 6, when the sewing machine is driven and the cam 23 is rotated in the direction indicated by the arrow mark and the cutout portion 23a of the cam 23 is positioned opposite to the follower tip 31a of the follower member 31, the actuating mechanism (29, 31) is turned counterclockwise around the pivot shaft 24b due to the action of the spring 30. In the meantime the clutch member 34 moves to the left with respect to the holding member 27, and also turns counterclockwise around the pin 29b by the action of the spring 33. After all, the actuating mechanism (29, 31) turns counterclockwise until the abutment 29a of the actuating member 29 is pressed against the second arm 26d of the locking member 26. On the other hand, the clutch member 34 turns counterclockwise until the stepped portion 34c of the clutch member 34 is pressed against the arm 27a of the holding member 27 and/or the abutment 29a of the actuating member 29.
In reference to FIGS. 4 and 7, as the cam 23 is further rotated and the circumferential portion 23b of the cam 23 comes again opposite to the follower tip 31a of the follower member 31, the actuating mechanism 29, 31 is turned clockwise around the pivot shaft 24b against the action of the spring 30. The clutch 34 is moved to the right with respect to the holding member 27 and the locking member 26 while the clutch member 34 is turned clockwise around the pin 29b against the action of the spring 33. In the meantime the clutch member 34 moves the locking member 26 to the right through the holding member 27 to thereby disengage the first arm 26c of the locking member 26 from the top 16c of the inclined cam face 16a, and the swingable frame 13 is going to swing back due to the action of the spring 14 (FIG. 2).
In reference to FIGS. 4 and 8, as the cam 23 is continuously rotated and the cutout portion 23a is positioned again opposite to the follower tip 31a of the follower member 31, the actuating mechanism (29, 31) turns counterclockwise again and releases the locking member 26. Then the first arm 26c of the locking member 26 engages the inclined cam face 16a as the cam face 16a goes up together with the swingable frame 13. In the meantime the clutch member 34 moves to the left with respect to the holding member 27 and the locking member 26 while the clutch member is turned counterclockwise around the pin 29b due to the action of the spring 33 until the stepped portion 34c of the clutch member 34 is pressed against the arm 27a of the holding member 27 and/or the abutment 29a of the actuating member 29.
Finally in reference to FIG. 5, as the cam 23 is continuously rotated and the circumferential portion 23b is positioned, again opposite to the follower tip 31a of the follower member 31, the actuating mechanism (29, 31) is turned again in the counterclockwise direction and the first arm 26c of the locking member 26 engages the lower end of the inclined cam face 16a while the second arm 26d of the locking member 26 engage the abutment 29a of the actuating member 29 to thereby hold the follower tip 31a of the follower member 31 out of the rotation path of the cam 23. In the meantime the clutch member 34 moves to the right with respect to the holding member 27 and the locking member 26 while the clutch member is turned clockwise due to the engagement between the first arm 34a of the clutch member and the arm 27a of the holding member 26. Simultaneously, the upper cam face 34b of the clutch member engages the second arm 34b of the clutch member 34. Thus the swingable frame 13 is unlocked or released from the locking member 26 and returns to the initial position due to the action of the spring 14, and the cam follower 3 is accordingly released and engages the newly selected pattern cam.
In this condition, the locking member 26 pulls the rod 22 to the right in FIG. 3 against the action of the compression spring 20 and accordingly the shaft 19 is moved in the same direction, and as the result, the plate 19a disconnects the portern selecting gear 7 from the dial 6.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of pattern cam selecting devices differing from the types described above.
While the invention has been illustrated and described as embodied in a pattern cam selecting device, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.
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In a pattern cam selecting device of a sewing machine having a plurality of stacked pattern cams, a swingable element is provided, which can be moved in one direction to disengage a cam follower from one of the stacked pattern cams. The cam selecting device further includes a locking element, a clutch mechanism, and actuating mechanism, and a cam rotated upon the rotation of a main shaft of the sewing machine. The swingable element is locked in the follower-disengaging position by the locking element while clutch mechanism is held in an inoperative position by a holding element. The locking element which normally engages the actuating mechanism includes a follower element which is held in a position out of a rotation path of the cam. The locking element releases the actuating mechanism to allow the follower element to come into the rotation path of the cam when the locking element is operated to lock the swingable element while the clutch means is operated in association with the movement of the actuating mechanism to move to an operative position. The clutch mechanism is operated to cause the locking element to unlock the swingable element as the cam starts to rotate and moves the follower element toward the position out of the rotation path of the cam.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part application claiming the benefit of U.S. application Ser. No. 11/462,579 filed Aug. 4, 2006, which claims priority to Provisional Application Ser. No. 60/705,743, which was filed on Aug. 5, 2005. The entire contents of both applications are incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates generally to methods of producing small diameter, continuous fibers, and specifically relates to methods of producing continuous polymer and ceramic nanofibers of arbitrarily long lengths.
BACKGROUND OF THE INVENTION
[0003] Fibrous materials, especially nanofibers, are a widely used industrial material, which in recent years have been the subject of numerous research and development efforts. A fiber can be defined as a three-dimensional structure that is much larger in one dimension then the other two. If an arbitrary object can be described by three characteristic length scales, a, b and c, then a fiber is described by a>>b and c. Frequently, a fiber takes the form of a long, cylindrically symmetric strand that has a circular cross-section that does not change significantly along the z-axis. Fibers are manufactured from all major materials classes (polymers, metals, ceramics and glasses) and are utilized in virtually every major industry in some form or another. They can be used in the form of single fibers, felts, textiles, cables, or reinforcing elements in composites, etc.
[0004] Fibrous materials provide enhanced flexibility, improved material properties, ultra-high surface area, chemical reactivity, increased strength, and the ability to transfer tensile loads using less material/volume. Despite these benefits, individual fibers are especially susceptible to damage, so they may often be used in combination with other materials. Multiple fibers may be combined to form textiles, metal wires, cables, polymeric cables, ropes, etc. Multiple fibers may also be used in fiber reinforced composites, wherein multiple fibers/textile layers are embedded in another material. This allows assembly of a large object with the properties of a fiber, wherein the surrounding material may provide protection, isolation, etc. Fiber reinforced materials may include fiberglass, carbon reinforced composites, metal and ceramic matrix composites etc.
[0005] Current research in the area of fibrous materials is focused on development of fabrication techniques that can produce nanofibers. Currently, nanofibers are produced by chemical synthesis methods, glass-drawing techniques, and modified extrusion strategies. Chemical synthesis methods rely on the controlled growth of a fibrous structure, in a liquid or gas environment, to produce a fiber in an atom-by-atom fashion. These methods are frequently used to produce single crystal whiskers of various inorganic materials, the best known of which is carbon nanotube synthesis. These techniques produce materials with extraordinary properties, but have proven entirely incapable of fabricating a continuous monofilament structure. In fact, short carbon nanotubes grown by these methods are currently being used as a feedstock for the production of continuous fibers via other extrusion-based methods.
[0006] Glassdrawing techniques have been utilized to produce continuous nanofibers from a limited selection of inorganic glass and polymer materials. Furthermore, a highly modified extrusion method known as electrospinning is often utilized for fabricating long nanofibers. Electrospinning involves the extrusion of a highly viscous polymer precursor through a relatively large aperture. This occurs simultaneously with the application of high voltage between the aperture and an appropriately positioned collector plate. Electric field effects cause the fluid to form a “Taylor cone” which is essentially a fluid instability at the center of the meniscus. A microscopic jet of precursor material emanates from the Taylor cone and is pulled to the collector plate by the applied electric field. The fluid jet propagates in a pseudo-random fashion, producing stretching and bending motions that further reduce the diameter of the fiber, which is eventually deposited on the collector plate. This process often produces a “nano-felt” material. Efforts to produce truly spoolable, continuous nanofiber with electrospinning focus on modified collection strategies such as spinning mandrels or electrode arrays. This allows the collection of highly aligned nanofibers, but does not produce a nanofiber that can be manipulated as a single continuous strand.
[0007] The difficulty of nanofiber production lies primarily in geometrical considerations, and the particularly small scale of the cross sectional features. Accordingly, the present invention is directed to a fiber fabrication method that can reliably produce the necessary nanoscale dimensions, yet allow the fiber length to be extended to arbitrary lengths. As demands increase for continuous nanofibers, the need arises for improved methods of producing these fibers, especially nanofibers having submicron dimensions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The following detailed description of the illustrative embodiments of the present invention can be best understood when read in conjunction with the following drawing, where like structure is indicated with like reference numerals and in which:
[0009] FIG. 1 is schematic view illustrating the method of forming continuous nanofibers according to one or more embodiments of the present invention.
SUMMARY OF THE INVENTION
[0010] According to a first embodiment of the present invention, a method of fabricating continuous nanofibers is provided. The method includes flowing an extrusion liquid through the column, and flowing a precursor liquid through the extrusion liquid, wherein the flowing precursor liquid has a viscosity less than the viscosity of the extrusion liquid. The method further includes reducing the diameter of the flowing precursor liquid by extruding the precursor liquid through the extrusion liquid, wherein the diameter of the precursor liquid is reduced by a factor of at least 5, and forming a continuous nanofiber by solidifying the extruded precursor liquid.
[0011] According to a second embodiment of the present invention, a method of fabricating continuous nanofibers is provided. The method includes providing a column, flowing an extrusion liquid through the column, wherein the extruding liquid defines a viscosity of from about 3,000 to about 15,000 centipoise, and a Reynolds number of from about 0.001 to about 1, and flowing a precursor liquid through the extrusion liquid, wherein the flowing precursor liquid defines a diameter of from about 50 to about 100 μm, a viscosity of from about 1 to about 10 centipoise, and a Reynolds number of from about 0.001 to about 1. The method further includes reducing the diameter of the flowing precursor liquid by extruding the precursor liquid through the extrusion liquid such that the diameter of the precursor liquid is reduced to about 5 μm or less, and forming a continuous nanofiber by solidifying the extruded precursor liquid.
[0012] Additional features and advantages provided by embodiments of the present invention will be more fully understood in view of the following detailed description.
DETAILED DESCRIPTION
[0013] Referring to FIG. 1 , methods and systems of fabricating continuous nanofibers are provided. The method includes providing a column 10 having an aperture 12 of about 100 to about 200 μm. Other aperture 12 sizes are also contemplated herein. In one embodiment, the column 10 comprises a pair of orifices 12 located at opposite ends of the column 10 . It is also contemplated that the column 10 may comprise various shapes. In one embodiment, the column 10 defines a cylindrical shape. The column 10 comprises a liquid material 20 flowing in the column 10 and configured to extrude a flowing precursor liquid 30 , which is fed to the column 10 . The precursor liquid 30 is delivered to the column by various means, for example, injected into the column by a syringe in the form of a liquid droplet.
[0014] The precursor 30 defines a viscosity less than the viscosity of the extrusion liquid 20 . In one embodiment, the precursor liquid 30 and extrusion liquid 20 may both be characterized as laminar flowing liquids. In a further embodiment, the precursor liquid 20 may have a Reynolds number of about 0.001 to about 10, and the extrusion liquid may have a Reynolds number of from about 0.001 to about 1000, or from about 0.001 to about 10. The precursor liquid 30 may define a viscosity slightly thicker than water, or from about 1 to about 10 centipoise, and the extrusion liquid 20 may define a viscosity of about 10,000 to about 15,000. In a specific embodiment, the extrusion liquid 20 may define a viscosity of from about 3,000 to about 5,000 centipoise.
[0015] The extrusion liquid could be composed of nearly any fluid with the appropriate viscosity and Reynolds numbers listed above. For example, and not by way of limitation, the extrusion liquid could include water-based materials, various polar or nonpolar solvents, or combinations thereof. The extrusion liquid may also include a melted plastic or a polymeric fluid. Similarly, the precursor may include any fluid with the appropriate viscosity and Reynolds numbers listed above. These may include, but are not limited to, a dissolved polymer, a melted polymer, a monomer solution, a solution of metallorganic chemicals, or combinations thereof.
[0016] After feeding the liquid precursor 30 to the column 10 , the precursor liquid 30 is extruded through the higher viscosity extrusion liquid, which reduces the diameter of the flowing precursor liquid 30 by a factor of at least 5. In one embodiment, the precursor liquid 30 entering the column 10 defines a diameter 32 of about 50 to about 100 μm, and after extrusion defines a diameter 38 of below about 10 μm, or in a further embodiment, below about 1 μm. In operation, the precursor 30 is extruded into long, stable liquid jets 35 with a diameter of about 10 μm or less. The highly viscous extrusion liquid 20 stabilizes the extruded precursor 35 , maintaining fiber geometry while solidification occurs. Solidification of the extruded precursor 35 results in a continuous nanofiber of variable lengths.
[0017] Moreover, solidification occurs before the effects of breakup occur. Under previous wet spinning methods, a low viscosity precursor e.g. a droplet would break inside a high viscosity fluid due to the formation of air bubbles. The air bubbles may be caused by external agitation, surface tension, etc. However, in the present invention, the low viscosity precursor is extruded and stabilized by the high viscosity extrusion liquid, such that the low viscosity precursor reaches very low micron or submicron dimensions before the precursor may be cut off i.e. produce multiple droplets. Thereafter, upon stabilization, the extruded droplet solidifies to produce continuous nanofibers, which is operable to be rolled into a spool. Solidification may occur by various methods known to one or ordinary skill in the art, for example, freezing, solvent evaporation, polymeric cross-linking, or combinations thereof. The method may produce continuous nanofiber, for example, polymers, ceramics, glasses, metals, or combinations thereof In specific embodiment, the method can be applied to the production of numerous fibers, such as nylon 6,6, polyethylene fibers, ceramic nanofibers, etc.
[0018] The dynamics and mechanics of this system, is explained in part by the Raleigh criterion, a well-known limitation of all fluid extrusion processes. The Raleigh criterion (see equation below) balances surface energy with fluid volume conservation, and determines the minimum diameter-to-length ratio of fluid column that can exist with stability in a given system. Any fluid jet with features smaller then a critical diameter will spontaneously decompose (breakup) into spherical droplets. In order to produce small diameter fibers, it is necessary to stabilize or solidify the columnar structure prior to decomposition into spherical droplets. However, this is made more difficult when the aperture size approaches submicron dimensions. Consider the pressure required to propel a fluid with viscosity m at a flow rate of Q, through a pipe of length L and diameter D:
[0000]
Δ
P
=
128
·
Q
·
μ
·
L
π
·
D
4
[0019] Note that the pressure is inversely proportional to D 4 , and will rapidly diverge as the aperture approaches submicron dimensions. Thus, relatively low viscosity fluids must be employed in order to extrude materials with nano-scale dimensions. However, this greatly accelerates the process of droplet breakup. There is also a practical lower limit to the speed of the solidification event due to the fact that immediate solidification will result in build-up of solid material at the aperture. The present process overcomes these issues by producing an ultra thin fluid structure and then stabilizing the geometrical structure for a sufficient length of time to allow solidification.
[0020] The precursor and the extrusion liquids may include various materials known to one of skill in the art. Below are some examples according to one or more embodiments of the present invention which include various materials operable for use in the present invention. For instance, a low viscosity solution of water may be injected at a controlled flow rate into a moving glycerin column. Flow control is accomplished by a Harvard Apparatus Pump 33 syringe pump. Tailoring the relative flow rates of the water and glycerin allows the generation of a long, stable fluid column with highly controlled diameter. In some embodiments, the filament diameter to needle diameter ratio for the syringe pump may be about 100, and even 1000 or more, thus demonstrating the amount of diameter reduction of the precursor solution.
[0021] Furthermore, the fabrication technique of the present invention has been utilized in generating fibers of two technologically important polymer materials, Polyvinyl butyral (PVB) and poly(p-phenylene terephthalamide) (PPPT, known commercially as Kevlar-21®). Polyvinyl butyral is a polymer that is commonly used in fibers, films and coatings. In order to generate fibers of this material, a 5% PVB/95% ethanol solution was injected into a laminar flowing water medium containing a viscosity enhancer (1% Aqualon Natrosol). Dissolution of ethanol into the water/Natrosol was observed to produce a continuous filament.
[0022] These fibers are collected in a highly aligned fashion. These fibers are 4-5 μm in diameter, and were fabricated with a 100 micron aperture. They exhibit significant surface roughness, which is most likely due to the large diameter of this fiber. As large diameter fibers solidify, radially nonuniform shrinkage can occur as the ethanol diffuses out of the polymer first from the surface, and then from the interior at a later time. This effect tends to becomes less pronounced with decreasing diameter. Glass micropipettes with tip inner diameters in the range of about 5 to about 10 mm have been utilized to fabricate smaller fibers with diameters of 1 mm and less.
[0023] Another experiment comprises a solution of 3% PPPT/97% Concentrated H2SO4, which is similar to the precursor used in the spinning of Kevlar fibers. The fiber fabrication method is capable of producing polymer fibers with ˜1 μm diameter or lower. The controlling factor is the ratio between precursor viscosity and that of the surrounding medium.
[0024] It is noted that terms like “preferably,” “generally”, “commonly,” and “typically” are not utilized herein to limit the scope of the claimed invention or to imply that certain features are critical, essential, or even important to the structure or function of the claimed invention. Rather, these terms are merely intended to highlight alternative or additional features that may or may not be utilized in a particular embodiment of the present invention.
[0025] For the purposes of describing and defining the present invention it is noted that the terms “substantially” or “about” are utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The terms “substantially” and “about” is also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.
[0026] Having described the invention in detail and by reference to specific embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. More specifically, although some aspects of the present invention are identified herein as preferred or particularly advantageous, it is contemplated that the present invention is not necessarily limited to these preferred aspects of the invention.
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Methods of fabricating continuous nanofibers include the steps providing a column, flowing an extrusion liquid through the column, and flowing a precursor liquid through the extrusion liquid, wherein the flowing precursor liquid has a viscosity less than the viscosity of the extrusion liquid. The method further includes reducing the diameter of the flowing precursor liquid by extruding the precursor liquid through the extrusion liquid, wherein the diameter of the precursor liquid is reduced by a factor of at least 5, and forming a continuous nanofiber by solidifying the extruded precursor liquid.
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BACKGROUND OF THE INVENTION
This invention relates to compositions for preparing polymer concrete useful for the protection or reconditioning of surfaces and for other applications.
A polymer concrete (sometimes abbreviated herein as "PC") is a composite material formed by polymerizing a monomer in admixture with an aggregate, wherein the polymerized monomer operates as a binder for the aggregate. These materials are to be distinguished from a polymer-impregnated concrete and from polymer-portland cement concrete. The former is a precast portland cement concrete subsequently impregnated with a monomer which is polymerized in situ, and the latter is a premixed material wherein either a monomer or polymer is added to a fresh concrete mixture in a liquid, powdery or dispersed phase, and subsequently polymerized (if needed) and cured. PC materials, as contrasted with polymer-portland cement concrete, are prepared from substantially non-aqueous compositions.
PC compositions, as well as the related polymer-impregnated concrete and polymer-portland cement concrete compositions, are reviewed in Chemical, Polymer and Fiber Additives for Low Maintenance Highways, edited by G. C. Hoff et al, Chemical Technology Review No. 130, Noyes Data Corporation, Park Ridge, N.J. 1979, particularly Chapter 10, "Polymers In Concrete," pages 430-479. Another review is Chemical Materials for Constructions, Phillip Maslow, Structures Publishing Company, Farmington, Mich., 1979, particularly Chapter 4, "Epoxies With Concrete", pages 280-340. Representative patents concerning polymer concrete materials are U.S. Pat. Nos. 4,500,674--Fontana et al and 4,460,625--Emmons et al.
Typically, a composition for preparing a polymer concrete is a substantially non-aqueous slurry of an aggregate, a monomer binder system and a polymerization catalyst. These components are often packaged separately and mixed on-site, to avoid premature polymerization. Among the monomers used as binders are low viscosity monomers such as methyl methacrylate and styrene used singly or in admixture, and sometimes with other monofunctional monomers or with polyfunctional monomers such as trimethylol propane trimethacrylate. Polyester-styrene, furan, vinyl ester and epoxy resins and oligomers have also been used in preparing polymer concretes, in each case in combination with suitable catalysts for initiating and/or accelerating the curing of the compositions.
Generally, polymer concrete compositions exhibit substantially greater compressive strength, flexural strength and durability (chemical resistance), and essentially zero permeability to liquids, as compared with portland cement concrete. Despite such advantages, the known polymer concrete compositions tend to shrink unduly during hardening, cure either too slowly or with difficulty (often because of inhibition from ambient oxygen), and present environmental hazards because of volatile organic components.
SUMMARY OF THE INVENTION
It has now been found that the foregoing and other deficiencies of polymer concrete compositions may be eliminated or substantially reduced by employing as the monomer binder component of the composition, a thermoplastic macromonomer comprising a solid, linear polymer terminated at one or both ends with a functional group which is addition or condensation co-polymerizable with a liquid comonomer component. The macromonomer, because it is already in a highly polymerized state, is inherently flexible and will exhibit little or no shrinkage upon copolymerization with the comonomer component. Moreover, the macromonomer apparently creates an oxygen barrier at the surface of the curable PC composition, thereby inhibiting the entry of ambient oxygen, a known polymerization inhibitor. Cure rate is therefore faster and/or more controllable at ambient temperature. Still further, because the macromonomer component is a solid, it has no tendency to flash and will reduce the flash point of the total monomer mixture of the PC composition.
The macromonomer also permits more effective control of viscosity of the PC composition, and the hardness and other properties of the cured material, by selection of molecular weight and type of macromonomer and comonomer components. In particular, because of the inherent flexibility and low shrinkage properties of the macromonomer component, the PC composition can include multifunctional monomers without detriment to the physical properties of the cured PC, including adhesion (shear bond). This benefit is not achievable with other, methacrylate-based, PC compositions. The PC compositions can also be formulated for low volatility and for substantially odorless, non-toxic application.
Accordingly, one aspect of the invention is a composition for preparing a polymer concrete, comprising a substantially non-aqueous slurry of (1) an aggregate material and (2) an amount of a monomer binder system effective, upon curing, to bind the aggregate into a polymer concrete, wherein the binder system comprises (a) a liquid comonomer component, (b) a solid, linear, thermoplastic macromonomer component, the macromonomer component being dissolved in the liquid monomer component and copolymerizable therewith through an addition or condensation mechanism, and (c) a polymerization catalyst.
In another aspect of the invention, a method of protecting or reconditioning a surface is provided wherein the surface is treated, e.g., coated or impregnated, with the aforesaid slurry, and the slurry is then permitted to cure under ambient conditions.
Other aspects of the invention include the surface obtained by practice of the protective or reconditioning method of the invention, and, as an article of manufacture, a multi-package system for admixture at the site of a surface to be reconditioned, wherein the packages comprise the aggregate material and the monomer binder system described above, respectively. The packaged components include a polymerization catalyst blended with the aggregate, or divided between the aggregate and the binder system. The catalyst may also be packaged separately in a manner described hereinafter.
DETAILED DESCRIPTION
The macromonomer component (b) of the PC compositions of the invention is a known thermoplastic material which is normally solid, i.e., solid under normal, ambient PC use conditions. Suitable macromonomers are described in numerous patents and other technical literature, including U.S. Pat. Nos. 3,786,116 and 3,862,267 to Milkovich et al, and other patents of Milkovich et al referenced in the article "Synthesis of Controlled Polymer Structures" by Ralph Milkovich, Anionic Polymerization, Chapter 3, pages 41-57, American Chemical Society (1981); U.S. Pat. Nos. 3,225,089--Short, 3,308,170--Pritchett et al, 4,169,115--Tung et al, and European Patent Application No. 104,096 of Husman et al, published Mar. 28, 1984 (priority U.S. Ser. No. 419085 filed Oct. 16, 1982); and the article "Carbanions, Living Polymers, and Electron Transfer Processes", M. Szwarc, in Synthetic Polymer Chemistry, Chapter II, pages 95-103, Interscience Publishers (1968). All of the foregoing patents and technical literature, including the patents and technical articles referenced therein, are incorporated herein by reference. The various patents to Milkovich et al referenced above are for convenience referred to herein collectively as the "Milkovich patents."
As indicated above, the macromonomer component is a linear polymer which is terminated at one or both ends with an addition or condensation copolymerizable group and is therefore characterized as monofunctional or difunctional. If the macromonomer is monofunctional, it generally copolymerizes with a comonomer to form a graft copolymer; if difunctional, the copolymerization product generally will be a block copolymer.
Representative of monofunctional macromonomers which are addition copolymerizable are those of the formula R--Z ) n X wherein R is a hydrocarbon group containing up to about 20 carbon atoms, Z is a residue of a vinyl aromatic monomer, n is a positive integer such that the number average molecular weight of Z is about 2,000-100,000 or more, and X is a polymerizable, monoethylenically unsaturated end group. The molecular weight distribution (also known as "polydispersity", M w /M n ) may range up to about 3 or more, the preferable upper limit being about 2. Preferably, the molecular weight of the macromonomers attributable to the vinyl aromatic portion may range from about 3,000 to about 50,000, more preferably about 3,000 to 30,000. In the macromonomer formula R--Z-- n X, the polymerizable end group (X) itself may be oligomeric or polymeric, or may be a straight or branched-chain group, aliphatic or aromatic, and may contain one or more oxygen atoms. Generally, X may contain up to about 250 carbon atoms.
Preferred structures of X are the following: ##STR1## wherein R' is phenylethylene or C m H 2m , m is 2, 3 or 4, p is a positive integer of from 2 to 8, y is a positive integer of from 1 to 50, and R" is hydrogen or lower alkyl (C 1 -C 8 ). Most preferably, X is the residue of the reaction of an ethylene oxide group with acryloyl chloride or methacryloyl chloride and is thus defined by the structure ##STR2## where R" is hydrogen or methyl.
From the standpoint of economical synthesis, the most preferred macromonomer is R--Z-- n X wherein R is lower alkyl (preferably 4 to 8 carbon atoms), Z is styrene or alpha methylstyrene and X is ##STR3## where R" is hydrogen or methyl.
Typical of the macromonomers which are condensation copolymerizable are those having one or two terminal hydroxyl or thiol groups, rendering them useful for condensation copolymerization with comonomers containing groups having active hydrogen atoms as defined by the Zerewitinoff method described in Kohler et al, J. Am. Chem. Soc., 40, 2181-8 (1927), such as carboxyl, amino or isocyanate groups, or combinations of such functionality. The hydroxyl- or thiol-terminated macromonomers are prepared in a manner analogous to vinylidene-terminated macromonomers, by anionic polymerization of one or more conjugated dienes, one or more vinyl aromatic hydrocarbons such as styrene, or alpha-methylstyrene, or mixtures thereof, using an alkali metal initiator such as lithium metal, butyl lithium or a di-lithium compound, to form living polymers or copolymers terminated at one or both ends with the alkali metal, followed by capping with an alkylene oxide, alkylene epi sulfide or sulfur to form an epoxide, episulfide or mercapto terminated copolymeric macromonomer wherein the epoxide or episulfide groups are easily hydrolyzable to hydroxyl or thiol groups, respectively. If a mixture of diene and vinyl aromatic hydrocarbon is used in the anionic polymerization, the macromonomer product is a random copolymer. If only one of the diene and vinyl aromatic monomers is polymerized, followed by copolymerization with the remaining monomer, the product is a block copolymer.
Typical conjugated dienes useful in preparing the foregoing condensation macromonomers are those containing 4 to 8 or more carbon atoms such as 1, 3-butadiene, 2-methyl-1, 3-butadiene (isoprene), 2, 3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, and the like. The vinyl aromatic hydrocarbons include styrene, alpha-methylstyrene, and nuclear-substituted styrenes such as vinyl toluene, indene, and p-tert butylstyrene.
Patents which describe such condensation macromonomers are the Milkovich patents, particularly U.S. Pat. Nos. 3,786,116 and 3,842,050; U.S. Pat. Nos. 3,225,089, 3,308,170 and 4,169,115; and European Patent Application Publication No. 104046, cited above. Other suitable condensation macromonomers are described in Macromolecular Reviews, 2, 74-83 (1967), incorporated herein by reference along with the above-cited patents.
Suitable comonomer components (a) are any liquid compounds, including oligomers, resins and other macromonomers, which copolymerize with and initially also solubilize the normally solid macromonomer component (b) in the presence of a catalyst. Because of their dual utility as solubilizers and comonomers, the comonomer components (a) are often characterized as "reactive diluents".
When the polymerizable groups of the macro-molecular component (b) are addition copolymerizable, the comonomer component (a) comprises one or more substantially non-volatile materials of up to about 2,000 molecular weight selected from monoethylenically unsaturated materials, polyethylenically unsaturated materials and mixtures thereof. Amounts of polyethylenically unsaturated materials greater than about 5 percent by weight of the total mixture of comonomer (a), macromonomer (b) and catalyst (c) may introduce a degree of crosslinking in the cured polymer concrete which, although increasing hardness and chemical resistance, may render the product too rigid and brittle for some applications. For many PC applications, however, thermoplastic rather than thermoset properties are desirable, and in such cases, therefore, a monofunctional comonomer will be the only comonomer or at least will be a major proportion of the comonomer component (a).
Representative of monofunctional comonomers include vinyl monomers such as acrylic acid, methacrylic acid, itaconic acid, and the like; the lower alkyl esters of acrylic or methacrylic acid, including methyl methacrylate, ethyl acrylate, 2-ethylhexyl acrylate, butyl acrylate and isobutyl methacrylate; the corresponding hydroxyl acrylates and methacrylates such as hydroxyethyl acrylate and hydroxypropylacrylate; vinyl esters such as vinyl acetate and vinylidene chloride; and particularly the high solvency monomers such as 2,2-ethoxyethoxyethyl acrylate, tetrahydrofurfuryl methacrylate and acrylate, n-laurylacrylate, 2-phenoxyethylacrylate and methacrylate, glycidyl acrylate, glycidyl methacrylate, isodecyl acrylate, isooctyl acrylate and methacrylate, and the like. Other monoethylenically unsaturated reactive diluents include vinyl aromatics such as styrene, alpha-methylstyrene, vinyl toluene, indene and p-tert butylstyrene; ethylenically unsaturated acids such as fumaric acid, maleic anhydride and the esters thereof; and nitrogen containing monomers such as acrylonitrile, methacylonitrile, acrylamide, methacrylamide, N,N-dimethacrylamide, N-vinylpyrrolidine, N-vinylcaprolactam, and the like.
As a general rule, the foregoing mono-unsaturated comonomers will have lower second order (glass) transition temperatures, T g , as homopolymer, than the macromonomer, but in some cases will not be as reactive as the polyunsaturated comonomers. Generally, also, the monoacrylates are good viscosity reducers whereas the polyacrylates, being more reactive, will be used to improve curing rate as well as to crosslink. The corresponding methacrylates are preferred when skin contact with the PC compositions is a risk, since methacrylates are less skin irritating than acrylates.
The polyethylenically unsaturated reactive diluents include polyol polyacrylates and polymethacrylates, such as alkane (C 2 -C 16 ) diol diacrylates, aliphatic (C 2 -C 16 ) polyacrylates, alkoxylated aliphatic polyacrylates such as described in U.S. Pat. No. 4,382,135, polyether glycol diacrylates and the like. Typical of the foregoing are 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, 1,3-butylene glycol diacrylate, tripropylene glycol diacrylate, polyethylene glycol 200 diacrylate and tetra-ethylene glycol diacrylate. Other polyunsaturated reactive diluents are allyl compounds such as allylmethacrylate and diallylmethacrylate; acrylated epoxies, aminoplast acrylates and unsaturated polyesters; trimethylol propane based polyacrylates such as trimethylolpropane triacrylate; the pentaerythritol-based polyacrylates or polymethacrylates described in U.S. Pat. No. 4,399,192; acrylic and methacrylic oligomers; acrylated polymer or oil such as acrylated oligomers; acrylated polymer or oil such as acrylated epoxidized drying-type oils, acrylated bisphenol A/epoxy resins, ethoxylated bisphenol A diacrylate, acrylated urethane prepolymers (also known as "acrylated polyurethanes"), polyethers, silicones, and the like.
The comonomers of component (a), particularly those which are polyfunctional, are conventionally sold with a free radical polymerization inhibitor content ranging from about 25 to 2000 ppm on comonomer weight.
The foregoing and other mono- and polyfunctional comonomers (a) (and inhibitors if used) are widely known and are described in the patent and other literature, such as component (1) of U.S. Pat. No. 3,368,900, component (2) of U.S. Pat. Nos. 3,380,831 and 3,594,410, the polymerizable vehicles disclosed in U.S. Pat. Nos. 4,163,809 and 4,481,258, and the acrylated polymer or oils, acrylic oligomers and other radiation curable component (b) compounds disclosed in U.S. Pat. No. 4,360,540. All of the aforementioned patents are incorporated herein by reference.
In addition to reactivity and degree of cross-linkability, if desired, the comonomers of component (a) will be selected on the basis of their solvency for the macromonomer component (b) and contribution to the viscosity of the resulting solutions. PC compositions ranging from sprayable to extrudable character can thus be prepared. Generally, the less polar the comonomer, the greater the solvency for the macromonomer. In those cases where solvency of a macromonomer in a single comonomer is insufficient, one or more other comonomers may be added to optimize compatibility. The higher the molecular weight of the macromonomer the less soluble the macromonomer will be in some of the comonomers. Accordingly, molecular weight of macromonomer must be balanced with the ease with which slurries can be formed with the aggregate and acceptability of the resulting viscosities and properties relative to the end uses of the PC compositions. If the intended end use is as a continuous resurfacing composition, for example, lower macromonomer molecular weight, e.g., not over about 50,000, may be required in order to obtain good solvency and low viscosity in a given comonomer component or mixture of diluents. The formulator of PC compositions is well aware of the foregoing and other considerations and can make appropriate selections of components of the compositions and proportions by routine experimentation and judgment in order to obtain a desired balance of properties.
In the case of condensation copolymerizable macromonomers, the comonomer component (a) will be a low molecular weight compound, an oligomeric material or a polymeric material having one or two active hydrogen-containing groups (as hereinabove defined) for condensation with the terminal carboxyl, epoxide, episulfide, hydroxyl, thiol or mercapto groups of the macromonomer. Comonomers capable of condensation copolymerization are well known and include polybasic acids and anhydrides, such as adipic acid, phthalic anhydride, maleic anhydride, succinic anhydride, and the like, to form polyesters; aldehydes, such as polyformaldehyde, acetaldehyde, and ureaformaldehyde, to form polyacetals; polyisocyanates and polyisocyanate prepolymers, to form polyurethanes; and siloxanes to form polysiloxanes. Furthermore, as is well known, living polymers terminated with halo maleic anhydride, halo maleate ester or epoxy groups may be converted to terminal carboxyl or hydroxyl groups by conventional base hydrolysis.
The foregoing and a variety of other comonomers and directions for modifying macromonomer components for condensation polymerization, are well known such as described in the Milkovich patents referenced above (for example, U.S. Pat. No. 3,786,116, columns 13-17) and the article by Szwarc also cited above. Considerations of solvency for macromonomers and viscosity similar to addition-copolymerizable systems, as described above, apply to condensation-copolymerizable systems, and the comonomers may likewise be easily selected by the skilled PC composition formulator on the basis of solvency and viscosity control, and desired degree of thermoplasicity of the copolymerized material in the PC composition.
Generally, for both addition and condensation binder systems of the invention, because of the high molecular weight of the macromonomer component as compared with the comonomer component, the amount of macromonomer component (b) may be less than the amount of comonomer. Of course, in cases where the comonomer component is itself a polymeric material, the macromonomer component may be in major amount of the copolymerizable binder system. Accordingly, depending upon the molecular weight of the comonomer, the proportion of macromonomer to comonomer may range from about 99:1 to 1:99 on a weight basis.
A catalyst system (c) appropriate for the polymerization mechanism of the particular copolymerizable binder system will be used. Normally, the catalyst system is a non-radiation responsive type since photo-initiated PC compositions have little practical value. For copolymerization of macromonomers and comonomers having terminal ethylenic unsaturation, free radical catalyst systems are more commonly employed. Preferably, the free radical catalyst comprises an oil-soluble organic azo or peroxy primary catalyst (initiator), often in combination with a co-catalyst, also known as an accelerator or promoter, each being selected for effectiveness under ambient temperatures. Typical proportions of primary catalyst to co-catalyst are about 9:1 to 5:5. If only a primary catalyst is used, it may be necessary to heat the PC composition to induce curing. Generally, useful accelerators are reducing agents such as tertiary amines, asorbic acid including isomers, reducing sugars, or transition metal organic compounds such as cobaltous acetylacetonate and other "siccatives" (drier salts) described in U.S. Pat. No. 4,460,625.
The organic peroxy primary catalysts include diacyl peroxides such as acetyl peroxide and benzoyl peroxide; ketone peroxides such as 2,4-pentanedione peroxide; peroxyldicarbonates such di (sec-butyl) peroxydicarbonate; peroxyesters such as alpha-cumylperoxy neodecanoate and t-butylperoxy benzoate; dialkyl peroxides such as dicumyl peroxide; and the like. The foregoing and other organic peroxides are sold by Pennwalt Corporation under the trademark and designation "Lucidol" and are conveniently selected on the basis of their stability as measured by half-life at desired temperatures of use. Other suitable catalyst systems are those described in the patents and publications cited above, such as U.S. Pat. No. 3,786,116, columns 18 and 19.
Cationic polymerization catalysts may also be used for addition copolymerizable binder systems, but such catalysts are generally more practical for condensation copolymerizations. The Milkovich patents disclose suitable condensation polymerization catalysts. Such catalysts include Lewis acids of which boron trifluoride, stannic chloride and aluminum chloride are representative. Useful cocatalysts (promoters) include water, alkyl halides, alcohols or combinations thereof.
The aggregate material of the PC compositions may be any inert inorganic particulate substance such as sand, gravel, crushed stone of various types, pebbles, and finely divided materials such as portland cement, powdered chalk, clay, flyash and silica flour, including mixtures of any of the substances. Generally, the aggregate will be selected to give a void volume which will require minimal amounts of monomer binder system to fill the voids and to give good workability. It is known that for a well-graded aggregate, larger maximum particle sizes require less resin but that smaller maximum particle sizes produce higher strength in the polymer concrete. Accordingly, depending upon the type and viscosity of the monomer binder system, one skilled in the art can select appropriate aggregate gradation, maximum particle size and composition for balance of amount of monomer binder system and desired PC strength. A typical composition, based upon a crushed stone/sand aggregate, will contain aggregate and monomer binder systems in proportions ranging from about 9:1 to 1:5, but preferably about 5:1 to 1:1 since compositions containing higher proportions of monomer binder system may be unduly expensive.
The PC compositions of the invention may also contain various additives for special properties and effects. Thus, fillers and flow control agents of various types may be added to assist in application and to modify the properties of the cured PC composition. Coloring agents may also be added, such as pigments or dyes, either to the aggregate or other component of the PC composition, or to the PC composition after blending. Sometimes the addition of coloring material or other agent will require dispersion of the additive in an aqueous medium, alone or in admixture with an emulsifier or surfactant, prior to blending with the PC composition or a component thereof. The presence of these minor amounts of water is not intended to be excluded by the term "substantially non-aqueous" as a descriptor of the PC compositions.
The aggregate and monomer binder system may be admixed in any manner suitable for control of the copylymerization of the binder components and convenience of use of the PC composition. For example, the aggregate, the macromonomer/comonomer blend of the monomer binder system and polymerization catalyst may be brought to the application site in separate packages and then admixed either manually or by the use of known metering/blending devices in the requisite proportions and sequences to obtain a PC composition having a viscosity and pot-life appropriate for the intended application. For example, if the application is discrete patching of a surface, a short pot-life (several minutes or hours) may be acceptable. On the other hand, if the application is continuous or in large quantities, such as reconditioning of a surface by continuous coating, resurfacing or impregnating, a pot-life of 4 to 8 hours or more may be required. In all applications, of course, the ambient temperature is an important consideration from the standpoint of the cure rate desired for the application. The skilled formulator and applicator of PC compositions is well aware of these and other conditions and can readily select components of the PC compositions and proportions as well as mode of application suited to the specific use.
When the components of the PC composition are packaged separately, the polymerization catalyst may be pre-admixed with the aggregate, or split between the aggregate and monomer binder system, e.g., primary catalyst in either the aggregate or monomer binder system, and co-catalyst in the other of the aggregate and monomer binder system. Primary catalyst and co-catalyst (if used) may also be blended in a separate package.
The PC compositions of the invention may be used in a wide variety of circumstances for the protection and/or reconditioning of surfaces, whether the mode of application be by coating, patching, impregnating or other technique. For example, the PC compositions are useful as overlays on standard concrete for bridge decks (to seal off and to prevent moisture and salt penetration, and resultant corrosion and disintegration), as fast-cure (several hours up to a day or more) patches for roads and walkways, and as industrial coatings to prevent acoustic or acid-corrosion of platforms, conduits, reactors, dam structures, industrial passages, and the like.
The following will specifically exemplify the invention but is not intended to limit the scope thereof.
MACROMONOMER PREPARATION
A glass and stainless steel reactor is charged with 1100 grams of cyclohexane, pre-dried over molecular sieves, and 400 grams of styrene purified over activated alumina. The reactor temperature is raised to 70° C. and s-butyllithium solution (1.4M in cyclohexane) is slowly added until a persistant light reddish-orange color is obtrained. An additional 100 ml (0.140 moles) of s-butyllithium is immediately added. Styrene is then pumped into the reactor for 30 minutes until a total of 1820 grams has been added. The temperature is maintained at 70° C. for 30 minutes and then 12.3 grams of ethylene oxide (0.28 moles) is added causing the solution to become colorless. To the resulting solution is added 16.1 grams (0.154 moles) of methacryloyl chloride to give upon removal of cyclohexane a solid macromonomer having the structural formula: ##STR4## where n has a value such that the molecular weight is 13,000 as measured by GPC. The macromonomer product is purified by dissolving the solid material in toluene to form a 40 percent by weight solution. This solution is filtered through a half-inch bed of Celite 545 filter filtered through a half-inch bed of Celite 545 filter aid (Fisher) using water aspiration suction. The filtered toluene/macromonomer solution is reprecipitated into excess methanol and vacuum dried to provide a product which gives a non-cloudy (water white) solution when dissolved in toluene. The purified product is identified as macromonomer A in the following description.
POLYMER CONCRETE COMPOSITIONS
An aggregate is prepared by uniformly mixing crushed stone (1/2 to 3/4 inch maximum size) and sand (rounded grain) in a ratio of 300 parts by weight of stone to 200 parts by weight of sand, and screening out all material passing a No. 50 sieve. A monomer binder system is prepared by dissolving macromonomer A in a comonomer component and adding cumene hydroperoxide (73% active) free radical initiator (primary catalyst). Cobaltous acetylacetonate co-catalyst (promoter) is uniformly admixed with the aggregate. PC compositions are then formulated by blending the monomer binder system into the aggregate-promoter mixture wherein the amounts of the components are:
______________________________________ Parts by Weight______________________________________Aggregate 500Monomer Binder Mixture 100Catalyst system:primary (initiator) 0.80co-catalyst (promoter) 0.10______________________________________
Table I below identifies the formulations and the composition of the monomer binder mixture in each formulation.
TABLE I______________________________________Monomer Binder Mixes Formulations______________________________________ 1A 1B 1C 1D(1) Macromonomer A 0 10 20 30 Isobornyl methacrylate 95 85 75 65 Trimethylolpropane 5 5 5 5 trimethacrylate 2A 2B 2C 2D(2) Macromonomer A 0 10 20 30 Tetrahydro furfuryl 95 25 75 65 methacrylate Trimethylolpropane 5 5 5 5 trimethacrylate 3A 3B 3C 3D(3) Macromonomer A 0 10 20 30 Methyl methacrylate 100 90 80 70 4A 4B 4C 4D(4) Macromonomer A 0 10 20 30 Isobornyl methacrylate 85 75 65 55 Polypropylene glycol 10 10 10 10 Monomethacrylate Trimethylolpropane 5 5 5 5 trimethacrylate______________________________________
Table II below summarizes predicted ratings on properties of the PC formulations measured by standard test procedures on the formulations in the pot prior to cure (flash point), during cure (surface cure time, i.e., time to tack-free surface) or after cure on a substrate at 25° C. ambient temperature (shrinkage, adhesion), where the rating is on a scale of 1 to 10 (worst to best), 1 indicating highest shrinkage, lowest adhesion, lowest flash point and slowest cure rate. The ratings indicate that the presence of increasing amounts of Macromonomer A will reduce shrinkage, increase adhesion, reduce flash point and enhance surface cure (reduce time to a tack-free surface).
TABLE II__________________________________________________________________________Ratings of Properties of PC-Formulations 1A 1B 1C 1D 2A 2B 2C 2D 3A 3B 3C 3D 4A 4B 4C 4D__________________________________________________________________________Shrinkage 5 6 8 10 4 5 7 8 4 5 2 8 5 6 8 10Adhesion 3 4 5 7 6 7 9 10 1 1 2 2 7 8 9 10Flash Point 6 7 8 9 7 8 9 10 1 1 1 1 7 7 9 10Surface Cure 3 5 6 7 3 6 7 8 8 8 8 8 3 5 7 7__________________________________________________________________________
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Composition for preparing a polymer concrete, a method of protecting or reconditioning surfaces by treatment with the composition, the protected or reconditioned surfaces thus-treated, and multi-package systems for bringing the components of the composition to an application site, wherein the composition comprises a substantially non-aqueous slurry of (1) an aggregate material and (2) a monomer binder system effective to bind the aggregate, upon curing, into a polymer concrete, the binder system comprising (a) a liquid comonomer component, (b) a solid, thermoplastic macromonomer component dissolved in the comonomer and comprising a linear polymer terminated at one or both ends with a polymerizable end group, and (c) a polymerization catalyst.
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RELATED APPLICATION
[0001] The present application is based on and claims priority to the Applicant's U.S. Provisional Patent Application 62/042,913, entitled “Chemical Composition For Dust Suppression And Soil Stabilization,” filed on Aug. 28, 2014.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates generally to the field of chemical compositions for dust suppression and soil stabilization. More specifically, the present invention discloses a chemical composition for dust suppression and soil stabilization that combines an asphalt emulsion with an aqueous magnesium chloride solution.
[0004] 2. Background of the Invention
[0005] A variety of chemical compositions have been used in the past for dust control and suppression, soil stabilization, erosion control, road stabilization and the like—particularly on unpaved roads, construction sites and oilfield sites. But, a single product has not been found that met all of expectations.
[0006] Two types of products are commonly used in the field. The first are water-based asphalt emulsions. For example, a water-based cationic asphalt emulsion, commonly known as CCS-1h, is commercially available from many suppliers. It is typically blended as an emulsion containing about 85% water and 15% asphalt and sprayed onto the road surface like a thick coating. It loses its moisture very rapidly with the heat of the sun and from the wicking by the sub-surface it is applied to. Traffic must be kept off of the product after spraying for an entire day as the traffic peels up the product on the tires of the vehicles. It must be applied again every seven to ten days as it forms cracks and potholes very quickly even on solidly-built roads. It is usually applied at the rate of about 0.48 gallons per square yard. This product also sits on top of the subsurface and is too thick to penetrate to any significant degree, and peels up very easily although it is a solid surface once it cures.
[0007] The other competing family of products in this field employ an aqueous solution of magnesium chloride (MgCl 2 ). For example, one typical formulation consists of magnesium chloride mixed with about 70% water by weight. It is widely used to control dust and also stabilizes the road and dirt and makes the material more solid. This solution is typically applied at a rate of about 0.5 gallons per square yard. The magnesium chloride does chase the water down through the subgrade and is dispersed throughout the subsurface and able to be reworked if more water is added. Magnesium chloride is hydroscopic and pulls moisture from its surroundings (i.e., ground humidity and surrounding material). The problem is that it must be reactivated with more water every few weeks because the salt crystals on the surface dry out and create their own dust that only adds to the problem. It also becomes slick during the wetting process and rain storms.
[0008] The prior art in this field also includes U.S. Pat. No. 6,855,754 (Takamura et al.). This patent discloses a paving/coating formulation that includes the combination of: (1) an asphalt emulsion; (2) a water solution of any of a variety of alkali or ammonium salts or hydroxides; and (3) a water solution of any of a variety of metal salts, including Group IIA salts such as magnesium chloride. However, the proportional ranges of ingredients mentioned in the Takamura patent are far outside those of the present invention. The present formulation uses much less asphalt emulsion and more magnesium chloride solution. Also, Takamura is primarily concerned with cold paving with an aggregate. Takamura mentions that the formulation could be used more generally for a coating. However, given the high proportion of asphalt emulsion in the Takamura composition, the result would be a thin surface coating similar to conventional asphalt coatings. In contrast, the present invention is intended for dust suppression by penetrating to a significant depth into the ground, rather than just forming a solid layer on the surface.
SUMMARY OF THE INVENTION
[0009] This invention provides a chemical composition for dust suppression and soil stabilization that includes a mixture of water-based asphalt emulsion and magnesium chloride solution.
[0010] These and other advantages, features, and objects of the present invention will be more readily understood in view of the following detailed description.
DETAILED DESCRIPTION OF THE INVENTION
[0011] The present invention is essentially a combination of asphalt emulsion and magnesium chloride solution that gains the benefits of both products. The result is a very durable product that lasts a long time and uses significantly less water. In the preferred embodiment of the present invention, the chemical composition of the product is about 4% asphalt (in emulsion), 25% magnesium chloride, 1% potassium sulfate and 70% water by weight. More generally, the chemical composition of the present invention can be about 1%-8% asphalt (in emulsion), and 19%-32% magnesium chloride, by weight, with the balance being water (e.g., about 60%-80% water). Optionally, the composition can also include about 0.05%-5% of an alkali salt (e.g., potassium sulfate). This corresponds to a ratio of about 20% asphalt emulsion (e.g., CCS-1h) and 80% magnesium chloride solution. It should be noted that other asphalt emulsions could be substituted.
[0012] The following is a discussion of the present applicants' test of the present invention. First, a commercially-available asphalt emulsion (CCS-1h) was diluted with water to make an emulsion containing about 35% asphalt emulsion and 65% water. It should be noted that the amount of water was cut back in comparison to the prior art discussed above, so when the magnesium chloride solution was added it would not thin it down too much. The resulting asphalt emulsion was then heated to about 150° F. A magnesium chloride solution containing about 30% magnesium chloride and 70% water was heated to about 160° F. This allowed the asphalt emulsion to not clot in the blending process. Both products were then placed in a tank with a recirculation pump and blended for about two hours. The product was then loaded into a distributor truck and applied to a test road surface. The subgrade of the road surface was wet down with water and the mixture was applied at a rate of about 0.25 gallons per square yard.
[0013] The results were amazing. The test road surface gained the durability of the emulsion on the top layer and the water retention of the magnesium chloride solution. The product also allowed the asphalt emulsion in the mixture to soak down into the ground as deep as the magnesium chloride solution normally does, instead of just sitting on the top the way asphalt emulsion normally would on its own. With the product being dispersed throughout the base material instead of just sitting on top, it is not brittle and stays hydrated and no cracks have formed in a week. Asphalt emulsions, such as CSS-1h, normally start showing cracks and failures within a few days after application. There was also the benefit in water savings at around 35% less water used in initial preparation of the this new product. It is estimated that total water savings over the useful life of the product will end up being about 50-60% of the water normally used with either of the conventional products alone over a comparable period.
[0014] The above disclosure sets forth a number of embodiments of the present invention described in detail with respect to the accompanying drawings. Those skilled in this art will appreciate that various changes, modifications, other structural arrangements, and other embodiments could be practiced under the teachings of the present invention without departing from the scope of this invention as set forth in the following claims.
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A chemical composition for dust suppression and soil stabilization includes a mixture of water-based asphalt emulsion and magnesium chloride solution.
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CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of application Ser. No. 08/783,121, filed Jan. 14, 1997, now abandoned.
BACKGROUND
The present invention relates to an electrode manufacturing method for rechargeable batteries, and more particularly, to an electrode manufacturing method in which, when manufacturing a positive electrode and a negative electrode of a battery, the coating of a binder can be effectively realized.
As is well known, rechargeable batteries are batteries that are able to be re-used by recharging. There are many types of rechargeable batteries including nickel-cadmium batteries, Ni-MH batteries, lead storage batteries, etc. Among these, there has recently been a sharp increase in the use of Ni-MH batteries as they are less harmful to the environment than the other types of rechargeable batteries.
In the above Ni-MH batteries, a nickel hydroxide is normally used for the positive electrode, and a hydrogen storage alloy is used for the negative electrode. When being charged, the water in the electrolytes is resolved, and the hydrogen storage alloy absorbs the hydrogen. When discharging electricity, hydrogen is discharged into the electrolytes. By the above process, the battery can be used and recharged repeatedly.
In the manufacturing process of the positive electrodes and negative electrodes of the nickel-hydrogen battery, a binder is coated on both electrodes to prevent the removal of an active material in the case of the positive electrode, and to increase hydrophobic properties on a face of the electrode in the case of the negative electrode.
There are two types of coating methods used in the prior art: a deposition method and a spray method. The deposition method is normally used for the positive electrode, and the spray method for the negative electrode. The two different methods are illustrated in FIGS. 2 and 3.
FIG. 2 illustrates the deposition method for coating the binder on the positive electrode. As shown in the drawing, the binder is coated on a positive electrode 1 by passing the positive electrode 1 through a deposition tub 9, filled with an aqueous solution, on rollers 3, 5, and 7. And as shown in FIG. 3, in the spray method for coating binder on the negative electrode, a negative electrode 11 receives a coating of binder through a spray nozzle 13 which sprays a solution of binder on a top face of the negative electrode 11.
In the prior art electrode manufacturing method using the above coating methods, however, there are a number of drawbacks. They include:
I. Coating binder on the positive electrode.
A. When the positive electrode passes through the inside of the deposition tub, some of the active material on the surface of the electrode is removed, reducing the capacity of the battery.
B. As the positive electrode is simply deposited in the deposition tub, it is difficult to control an exact amount and thickness of the binder.
C. High manufacturing costs are incurred as a result of having to repeatedly change the aqueous binder.
D. When depositing the positive electrode in the deposition tub, as swelling occurs in the binder when the aqueous binder permeates the positive electrode, a repressing operation must be performed, resulting in an increase in the number of total operations needed in the manufacturing process.
II. Coating binder on the negative electrode.
A. To improve the spraying of the aqueous binder, an organic solvent is added to the binder. However, composition is difficult to control.
B. Because the spraying of the binder and its thickness change according to the state of the nozzle, it is difficult to maintain a consistent thickness and quality of the sprayed binder.
SUMMARY
The present invention has been made in an effort to solve the above problems.
It is an object of the present invention to provide an electrode manufacturing method for rechargeable batteries that not only improves the manufacture of rechargeable batteries by reducing the number of steps needed in the coating of a binder to electrodes of a rechargeable battery, but also allows a high-quality adhesive coating to be easily applied to the electrodes.
To achieve the above objective, the present invention provides an electrode manufacturing method for rechargeable batteries which includes the process of coating a binder on positive and negative electrodes of a rechargeable battery, wherein the process of coating is realized by passing positive and negative electrodes through rollers, mounted facing each other and which receive a supply of aqueous binder for application.
According to a feature of the present invention, an outside circumference of the rollers is formed by using a material that can absorb the aqueous binder.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objectives and other advantages of the present invention will become apparent from the following description in conjunction with the attached drawings, in which:
FIG. 1 is a schematic perspective view showing an electrode manufacturing method for rechargeable batteries in accordance with a preferred embodiment of the present invention; and
FIGS. 2 and 3 are views showing an electrode manufacturing method for rechargeable batteries of the prior art.
DESCRIPTION
Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
Referring to FIG. 1, shown is a schematic perspective view showing a method of coating a binder to positive and negative electrodes of a rechargeable battery.
As is illustrated, the present invention is structured such that a positive electrode or a negative electrode 30 passes between rotating roller members 32 and 34 to receive a coating of binder. For purposes of distinguishing the method of the present invention from that of the prior art, this method will be referred to as a roll coating method.
The above rotating roller members 32 and 34 are rotatably mounted facing one another. Although only one pair of rotating rollers member 32 and 34 are shown in the drawing of the present invention, more roller members can be added to further enhance thickness control of the binder.
The space between the two rotating roller members 32 and 34 is adjusted to a degree such that a desired thickness of the binder can be attained. In addition, the roller member 32 comprises a roller 31 and an aqueous material absorbing member 33 which is disposed around an outer surface of the roller 31. The roller member 34 also comprises a roller 35 and an aqueous material absorbing member 37 which is disposed around an outer surface of the roller 35. Preferably, the aqueous material absorbing members 33 and 37 are made of a fibrous material.
The aqueous material absorbing members 33 and 37 are supplied with the aqueous or liquid binder as the rollers 31 and 35 rotate. The supply of the binder to the aqueous material absorbing members 33 and 37 is realized through supply nozzles 36.
The supply nozzles 36 are mounted so that they are able to supply an even coating of aqueous binder on the outer circumference of the rotating roller member 32 and 34. As with the rotating roller member 32 and 34, the number of supply nozzles 36 can be increased to improve thickness control of the binder.
The operation of the present invention structured as in the above will now be explained.
First, the roller members 31 and 35 are rotated. The outer circumference of the aqueous material absorbing members 33 and 35 are then supplied with the aqueous binder from the supply nozzles 36.
In this state, a user passes an electrode 30 through the roller members 32 and 34. As the electrode 30 passes through aqueous absorbing members 33 and 37, the outer circumferences of which are absorbent, the electrode 30 receives a coating of binder on its surface.
In the above, as the roller members 32 and 34 are rotated at a controlled speed, an appropriate amount of binder desired by the user can be coated on the surface of the electrode 30. After the coating process, the electrode 30 undergoes a drying process.
The chart below is a comparison between the binder coating method of the present invention, the roll coating method, and that of the prior art (deposition method, spray method).
______________________________________ roll coating deposition spray______________________________________active material no yes noremovalelectrode swelling no large amt. small amt.binder aqueous solution aqueous solution organic solventbinder small amt. large amt. medium amt.consumptioncontrol of easy highly difficult somewhatcoating amount difficult______________________________________
As can be seen in the above chart, the present invention has significant advantages compared to that of the prior art. The following is an explanation of these advantages.
First, because the amount of binder coating can be easily controlled, a binder coating layer can be formed on the electrodes at a desired thickness. This ability to control the thickness of the binder is made possible by controlling the number of supply nozzles which allows control of the amount of aqueous binder sprayed onto the rotating rollers. Also, thickness is controlled by controlling the rotating speed of the rotating rollers.
In addition, as the binder is supplied in an aqueous state in the present invention, problems resulting from the mixing of the organic solvent in the prior art can be avoided.
Finally, the problem of swelling in the binder when using the deposition method can be greatly reduced in the present invention as rotating rollers are used directly on the surface of the electrodes to apply the binder.
Although preferred embodiments of the present invention have been described in detail hereinabove, it should be clearly understood that many variations and/or modifications of the basic inventive concepts herein taught which may appear to those skilled in the present art will still fall within the spirit and scope of the present invention, as defined in the appended claims.
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Disclosed is an electrode manufacturing method for rechargeable batteries which includes the process of coating a binder on positive and negative electrodes of a rechargeable battery, wherein the process of coating is realized by passing positive and negative electrodes through rollers, mounted facing each other and which receive a supply of aqueous binder for application.
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[0001] The invention relates to the non-invasive ultrasonic diagnosis of lesions on tooth surfaces or under dental restorations such as gold crowns and other dental restorations. The invention further relates to the non-invasive ultrasonic diagnosis of lesions on interproximal tooth surfaces and/or interproximal areas of dental restorations such as gold crowns and other dental restorations. The invention also relates to the non-invasive ultrasonic diagnosis of periodontal disease. Tooth lesions diagnosed could be enamel caries, dentinal caries and cracks in the tooth. Similarly, periodontal disease diagnosed could be gingivitis and periodontitis. In particular, the invention relates to ultrasonic stress waves imparted through the tooth (transmitted from one transducer through the tooth, and/or gum and bone to a second receiving transducer) or through a dental restoration for the detection of said lesions.
BACKGROUND OF THE INVENTION
[0002] Non-destructive material evaluation is the identification of physical and mechanical properties of a piece of material without altering its end-use capabilities. One effective technique used to provide accurate information pertaining to the material properties is ultrasonic Stress Wave Timing. Stress waves, for the purpose of this patent, are the propagation of stresses distributed longitudinally through material. Wavelength can encompass any range. The preferred embodiment is between ten and thirty megahertz. As indicated, stress wave can be an ultrasonic wave pulse. The basic principle of stress wave timing is to use a stress wave to measure the speed of sound transmission by recording the time it takes to pass through material and/or attenuation of induced stress wave. The speed with which sound waves travel through a material is dependent upon the materials properties. The transmission of sound through materials and the related rates of travel and attenuations is a well-understood art. All of the above cited U.S. patents, other than one (U.S. Pat. No. 5,570,182), have used a related but different method of evaluating materials with ultrasound. They have looked at the ultrasound Pulse-Echo that is returned from structures or boundaries in the tooth being evaluated, that is they use an ultrasonic transducer to transmitted a ultrasound pulse into the tooth and then used the same transducer, or another very close to it, to receive the reflected energy, the echo of that pulse, off internal layers or other structures within the tooth they are looking into. U.S. Pat. Nos. 5,874,677, 6,162,177 and 6,190,318 transmit surface (Rayleigh) waves and these patents only look for the pulse-echo from this surface wave. They do not look through the tooth; they look around the outer surface of the tooth, to diagnose carious lesions. U.S. Pat. No. 5,570,182 uses light instead of sound as a medium to evaluate materials. Many articles have been published on the use of Pulse-Echo ultrasound in teeth also. (Ultrasonic Pulse-Echo Measurements in Teeth. FE. Barber, S. Lees, R. R. Lobene. Archs oral Biol., Vol. 14, 745-760, 1969), (Observation of Internal Structures of Teeth by Ultrasonography. G. Baum, I. Greenwood, S. Slawski, R. Smirnow. Science, Vol. 139, 495-496, 1962.
[0003] According to prior art, sound in dental materials travels at different speeds according to the material it is passing through. The slowest is the tooths pulp section, which has sound transmission characteristics very similar to water (Examination of the Contents of the Pulp Cavity in Teeth. G. Kossoff, C. J. Sharpe. Ultrasonic, 77-83, 1966), next is dentine at approximately four times faster. The fastest is in enamel at about six times faster than water (Determination of Ultrasonic Velocity in Human Enamel and Dentine. S. Y Ng, P. A. Payne, N. A. Cartledge, M. W. J. Ferguson. Archs oral Biol., Vol. 34, No. 5, 341-345, 1988). Dental caries, in general, would have a different transmission time, the time it takes for the stress (acoustic) wave to travel from the transmitting transducer to the receiving transducer, so the location and severity of material change (caries) can be found easily and quickly by recording multiple transmission times over an area. By using oscilloscopes, or other measuring or recording devices, transmission time, wave attenuation, transit times and wave shape, thus time and speed, can be recorded and evaluated. The sequence of transit times can be mapped onto the path taken by the receive and transmit transducer pairs as they are mechanically or electronically translated about the tooth. The resulting map can be thought of as an image of the shortest times taken by the stress wave through that region of the tooth defined by the transducer locations. Regions of anomalous transit times are interpreted as regions of dental caries or some other defect in the tooth structure. Mapping is the preferred embodiment of imaging, of the material (tooth and gums) that can be used to diagnose lesions such as enamel caries, dentinal caries and cracks in the tooth. (Development and Application of an Ultrasonic Imaging System for Dental Diagnosis. H. Fukukita, T. Yanco, A. Fukumoto, K. Sawada, T. Fujimasa, and I. Sciaenidae. Journal Of Clinical Ultrasound No. 13, 597-600, October 1985).
[0004] In particular, the invention relates to ultrasonic stress waves imparted through the tooth or dental restoration for the detection of these lesions. Periodontal disease, such as gingivitis, periodontitis can be diagnosed also.
[0005] Dental caries (dental cavities or tooth decay) is a disease manifested by local demineralization of the enamel and dentine of the tooth caused by dental plaque. The demineralization process progresses from the outer enamel surface of the tooth through the entire thickness of the enamel and into the dentine. Caries lesions of occlusal (biting surface), buccal (cheek side) and lingual (tongue side) surfaces can be diagnosed by mechanical probing and/or visual inspection. It is difficult or impossible to find small and medium size lesions of interproximal surfaces hidden by the gums and/or adjacent teeth. These can usually only be found with dental X-rays (radiographs). Although the use of bitewing radiographs is often used as a tool in the diagnosis of proximal caries lesions, this method has several weaknesses because of its relative insensitivity and user dependence in terms of technical skill and interpretation (Waggoner W., F. Crall J. J. Quintessence International 11/1984: 1163-1173). It should be noted that bitewing radiographs have a high proportion of X-rays taken in the dental office. This is contrary to current trends in safety standards that support every effort aimed at reducing the exposure to ionizing irradiation.
[0006] Caries lesions not adjacent to a dental restoration on a tooth surface site are known as primary caries, while caries lesions in contact with a dental restoration at the tooth surface are known as secondary caries. Secondary caries would be caries next to a filling or under a gold crown.
[0007] In conventional methods X-ray machines are used for the examination of dental tissue. Also apparatuses for measuring dense tissue by means of ultrasound are known in the art. The publication (Development and Application of an Ultrasonic Imaging System for Dental Diagnosis. H. Fukukita, T. Yanco, A. Fukumoto, K. Sawada, T. Fujimasa, and I. Sciaenidae. Journal Of Clinical Ultrasound No. 13, 597-600, October 1985), describes an ultrasound measurement method for examining teeth.
[0008] Because of the health hazards caused by high power levels required for x-ray fluoroscopy, it is impossible to obtain real-time information. More importantly the power level of X-rays used in dental offices cannot penetrate metal crowns used in tooth restoration. This means secondary caries and cracks in the tooth under the crown cannot be diagnosed.
[0009] In stress (acoustic) waves ultrasonic and sonic refer only to the frequency of excitation, ultrasonic being frequencies above 20 KHz used to impart a wave into the material. The velocity of a stress wave is dependent on the material properties only, not the frequency of excitation. All commercially available timing units give comparable results if calibrated and operated according to the manufacturers direction.
[0010] In existing art of ultrasonic procedure, an electrical device known as a pulser/receiver generates an electrical pulse to a transducer that changes the electrical pulse into an ultrasonic pulse (stress wave). The transducer, in turn, directs the ultrasonic pulse to any desired surface where it is transmitted thru that object and out the other side. The ultrasonic pulse received by a second transducer, the receiving transducer, is converted by said transducer to an electrical pulse for display on the cathode ray tube of the oscilloscope or other data processing equipment.
[0011] Ultrasonic devices such as transducers can be coupled to an object by air or water. While water is effective it is hard to use in an open environment such as a mouth. Transducers are more effective when used with a coupling medium such as acoustical gel or ultrasonic coupling devices. An ultrasonic coupling device could be a bladder made of an ultrasonic conducting membrane and filled with an ultrasonic conducting material like silicon, water, oil, etc. Focused ultrasonic transducers in prior art refer to transducer designed to concentrate ultrasonic sound waves to a spot at the focal length of the given transducer. This spot is usually much smaller in diameter than the face of the transducer. This focusing effect is the same for transmitting and receiving. By focusing a given transducer there is an increase in gain in the ultrasonic signal and an increase in the resolution of the device often to parts of a millimeter.
[0012] We propose the use of two classes of arrays of stress (acoustic) transducers. The first class represents one-dimensional arrays where the transducers are arranged in either a straight line (a linear array) on a curved line (curvilinear array). The second class represents two-dimensional arrays where the transducers are arranged on either a flat rectilinear grid or on a curved grid.
[0013] A phased array is an array of transducers and electronic circuitry that produce a focused receive and/or transmit stress (acoustic) beam. It functions in a manner similar to phased array RADAR.
SUMMARY OF INVENTION
[0014] It is an object of the invention to provide a method of detecting dental lesions under a gold crown or other dental restoration.
[0015] It is further an object of the invention to provide a method of detecting dental lesions under the gum line.
[0016] It is further an object of the invention to provide a method of detecting dental lesions in the interproximal area.
[0017] It is further an object of the invention to provide a non-invasive method of detecting or diagnosing periodontal disease.
[0018] It is also an object of the invention to be able to provide real-time ultrasonic tomography, a form of mapping or imaging, of a tooth and surrounding gum and bone material.
[0019] The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0020] [0020]FIG. 1 illustrates the main features of the first embodiment of the transducer system. It shows two ultrasonic transducers placed on opposite sides of a tooth. There would be an ultrasonic coupling device or material between the tooth and the transducer on each side of the tooth;
[0021] [0021]FIG. 1( a ) is a top view.
[0022] [0022]FIG. 1( b ) is a side view showing handling devices to hold the transducers in place.
[0023] [0023]FIG. 2 illustrates the main features of the second embodiment of the transducer system. It shows two focused ultrasonic transducers placed on opposite sides of a tooth. There would be an ultrasonic coupling device or material between the tooth and the transducer on each side of the tooth;
[0024] [0024]FIG. 2( a ) is a top view.
[0025] [0025]FIG. 2( b ) is a side view showing handling devices to hold the transducers in place.
[0026] [0026]FIG. 3 illustrates the main features of the third embodiment of the transducer system. It shows two ultrasonic transducers placed on opposite sides of a tooth. There would be an ultrasonic coupling device or material between the tooth and the transducer on each side of the tooth;
[0027] [0027]FIG. 3( a ) is a top view.
[0028] [0028]FIG. 3( b ) is a side view showing a laterally traversing fixture to hold the transducers.
[0029] [0029]FIG. 4 illustrates the main features of the fourth embodiment of the transducer system. It shows two focused ultrasonic transducers placed on opposite sides of a tooth. There would be an ultrasonic coupling device or material between the tooth and the transducer on each side of the tooth;
[0030] [0030]FIG. 4( a ) is a top view.
[0031] [0031]FIG. 4( b ) is a side view showing a laterally traversing fixture to hold the transducers.
[0032] [0032]FIG. 5 illustrates the main features of the fifth embodiment of the transducer system. It shows a horizontal array of ultrasonic transducers placed on opposite sides of a tooth. Each array would have two or more transducers. The transducers would be all on the same horizontal plane. There would be an ultrasonic coupling device or material between the tooth and the transducer on each side of the tooth;
[0033] [0033]FIG. 5( a ) is a top view.
[0034] [0034]FIG. 5( b ) is a side view showing a possible fixture to hold the horizontal array transducers.
[0035] [0035]FIG. 6 illustrates the main features of the sixth embodiment of the transducer system. It shows horizontal array of focused ultrasonic transducers placed on opposite sides of a tooth. Each array would have two or more transducers. The transducers would be all on the same horizontal plane. There would be an ultrasonic coupling device or material between the tooth and the transducer on each side of the tooth;
[0036] [0036]FIG. 6( a ) is a top view.
[0037] [0037]FIG. 6( b ) is a side view showing a possible fixture to hold the horizontal arrays of transducers.
[0038] [0038]FIG. 7 illustrates the main features of the seventh embodiment of the transducer system. It shows vertical array of ultrasonic transducers placed on opposite sides of a tooth. Each array would have two or more transducers. The transducers would be all on the same vertical plane. There would be an ultrasonic coupling device or material between the tooth and the transducer on each side of the tooth;
[0039] [0039]FIG. 7( a ) is a top view.
[0040] [0040]FIG. 7( b ) is a side view showing a laterally traversing fixture to hold the vertical array transducers.
[0041] [0041]FIG. 8 illustrates the main features of the eighth embodiment of the transducer system. It shows a vertical array of focused ultrasonic transducers placed on opposite sides of a tooth. Each array would have two or more transducers. The transducers would be all on the same vertical plane. There would be an ultrasonic coupling device or material between the tooth and the transducer on each side of the tooth;
[0042] [0042]FIG. 8( a ) is a top view.
[0043] [0043]FIG. 8( b ) is a side view showing a laterally traversing fixture to hold the vertical arrays of transducers.
[0044] [0044]FIG. 9 illustrates the main features of the ninth embodiment of the transducer system. It shows a horizontal and vertical array of ultrasonic transducers placed on opposite sides of a tooth. Each array would have two or more transducers. The each row of transducers would be all on the same horizontal or vertical plane respectively. There would be an ultrasonic coupling device or material between the tooth and the transducer on each side of the tooth;
[0045] [0045]FIG. 9( a ) is a top view.
[0046] [0046]FIG. 9( b ) is a side view showing a laterally traversing fixture to hold the arrays of transducers.
[0047] [0047]FIG. 10 illustrates the main features of the tenth embodiment of the transducer system. It shows a horizontal and vertical array of focused ultrasonic transducers placed on opposite sides of a tooth. Each array would have two or more transducers. The each row of transducers would be all on the same horizontal or vertical plane respectively. There would be an ultrasonic coupling device or material between the tooth and the transducer on each side of the tooth;
[0048] [0048]FIG. 10( a ) is a top view.
[0049] [0049]FIG. 10( b ) is a side view showing a laterally traversing fixture to hold the arrays of transducers.
[0050] [0050]FIG. 11 illustrates the first to the fourth embodiment of the transducer system with a block diagram of peripheral electrical and/or electronic components.
[0051] [0051]FIG. 12 illustrates the fifth to the tenth embodiment of the transducer system with a block diagram of peripheral electrical and/or electronic components.
[0052] [0052]FIG. 13 illustrates in detail a picture of a tooth with a gold crown with secondary lesions under the crown and a periodontal pocket and interfaces that can be shown and/or mapped by the invention.
[0053] [0053]FIG. 14 illustrates in detail a picture of teeth with an interproximal dental lesions that can be shown and/or mapped by the invention.
[0054] [0054]FIG. 15 illustrates a sample of received waveform as seen by a single receiving transducer.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0055] The present invention relates to a process of using through wave time of flight and other wave characteristics to detect dental lesions 41 in a tooth 40 . For our purposes, wave characteristics are the amplitude, phase, spatial position, timing, and general shape of the stress (acoustic) wave. A transducer system comprising of a transmitting ultrasonic transducer that transmits an ultrasonic pulse (stress wave) through dental material such as a tooth 40 or gum 45 , and a receiving ultrasonic transducer that receives the resulting ultrasonic pulse from the opposite side of the system and the resulting information, such as time of arrival of the stress wave and amplitude is processed. The system can include two or more transducers.
[0056] Due to the many possible paths through the tooth, the stress (acoustic) wave transmitted by the transmit transducer will result in many waves, separated in time, at the receive transducer. These many waves combine to produce a composite stress wave at the transducer that results in a complex electrical signal whose amplitude and phase directly corresponds to the composite stress (acoustic) wave (FIG. 15).
[0057] In principle, collecting such composite wave signals from all angles and positions through the tooth allows one to tease out all the paths taken by the transmit stress wave. Knowledge of these paths allows one to precisely locate and extent of every structure (and defect) of the tooth. Such a process is very complex and hence costly to implement.
[0058] Much structural information can be obtained by limiting the analysis of the composite signal to the transmission time of the shortest path, in time, of the stress wave. This analysis is well known in the field of non-destructive testing of wood structures.
[0059] In wood structures non-destructive material evaluation is the identification of physical and mechanical properties of a piece of material without altering its end-use capabilities. A technique used to provide accurate information pertaining to the material properties is stress wave timing. This basic principle of stress wave timing is to measure the speed of sound transmission time and/or attenuation of induced stress (acoustic) waves. The speed with which sound waves travel through a material is dependent upon the materials properties. Decayed regions, in general, would have a different transmission time so the location and severity of material change (decay) can be found easily and quickly by recording multiple transmission times over an area. Measuring wave attenuation is a variant of the speed measure in that the energy dissipation as a wave travels through the material is recorded. The wave attenuation measures can also provide a “map” of the material that defines the magnitude and extent of any decay.
[0060] The transit (transmission) time of the shortest path stress (acoustic) signal doubly useful as it is also the easiest to detect. It is easiest to detect because it is the first signal to arrive at the receive transducer. Nevertheless, there is some complexity in the choice of method used to detect the transmission time of the first signal.
[0061] One preferred method known in the art of wood testing is to set the level of an electronic threshold detector such that a stop signal is generated when the receive signal exceeds some preset level. This level is set just above the noise level of the instrumentation. Thus, and signal that exceeds this level is due to the stress signal. The transmission time is measured by a timer that begins with the transmit start (initiation) signal and stops at the first stop signal produced by the threshold detector.
[0062] Another preferred method uses an electronic peak detector to create the stop signal. The peak detector is set to create a stop pulse at each peak of the stress (acoustic) signal. Like the threshold detector, the peak detector will produce numerous stop signals but the transmission timer will always stop at the first stop signal, thus giving rise to the transmission time of the shortest path stress signal.
[0063] Yet another preferred method is to use either detector on the envelope of the received signal. Like the detectors, the creation of the envelope of the stress signal is known in the art. The first stop signal so produced will be at the point in time when the threshold level or the peak of the envelope of the stress signal has been reached. The advantage of using the envelope of the signal is that the resultant transit time is the transmission time of the energy in the stress signal.
[0064] Another preferred method uses a peak detector that works on the first derivative of envelope of the stress signal. Like the peak detector, the creation of the fist derivative of the stress signal is known in the art. The first stop signal so produced will be at the point, in time, when the slope of the shortest stress signal's energy is at its maximum.
[0065] Another preferred method uses a peak or threshold detector on the correlation signal produced by correlation of the received stress signal with the conjugate of the transmitted stress signal. Such correlation process is known in the art. The fist stop signal will be at the point, in time, when the received signal first matches the transmitted signal. This method allows the use of more complex transmit stress signals which in turn can increase the timing accuracy.
[0066] The present invention further relates to a process of using through wave time of flight and other wave characteristics to detect cracks in a tooth 40 comprising of a transmitting ultrasonic transducer that transmits an ultrasonic pulse (stress wave) through dental material such as a tooth 40 or gum 45 , and a receiving ultrasonic transducer that receives the resulting ultrasonic pulse from the opposite side of the system and the resulting information, such as time of arrival of the stress wave and amplitude is processed. The system can include two or more transducers.
[0067] The present invention further relates to a process of using through wave time of flight and other wave characteristics to detect dental lesions 41 on interproximal tooth surfaces and/or interproximal areas of dental restorations such as gold crowns 42 and other dental restorations, comprising of a transmitting ultrasonic transducer that transmits an ultrasonic pulse (stress wave) through dental material such as a tooth 40 or gum 45 , and a receiving ultrasonic transducer that receives the resulting ultrasonic pulse from the opposite side of the system and the resulting information, such as time of arrival of the stress wave and amplitude is processed. The system can include two or more transducers.
[0068] The present invention further relates to a process of using through wave time of flight and other wave characteristics to detect dental lesions 41 under gum tissue, comprising of a transmitting ultrasonic transducer that transmits an ultrasonic pulse (stress wave) through dental material such as a tooth 40 or gum 45 , and a receiving ultrasonic transducer that receives the resulting ultrasonic pulse from the opposite side of the system and the resulting information, such as time of arrival of the stress wave and amplitude is processed. The system can include two or more transducers.
[0069] The present invention also relates to a process of using through wave time of flight and other wave characteristics to diagnose periodontal disease such as gingivitis, periodontitis, comprising of a transmitting ultrasonic transducer that transmits an ultrasonic pulse (stress wave) through dental material such as a tooth 40 or gum 45 , and a receiving ultrasonic transducer that receives the resulting ultrasonic pulse from the opposite side of the system and the resulting information, such as time of arrival of the stress wave and amplitude is processed. The system can include two or more transducers.
[0070] The first embodiment of the present invention is shown in FIG. 1. It shows the overall concept of the transducer system 13 . The system is comprised of a pair of transducers placed opposite each other and in approximation to the tooth 40 to be examined. There needs to be a coupling agent or device present between the tooth 40 and the transducers. Each transducer would have handling device 2 attached to help position it.
[0071] The second embodiment of the present invention is shown in FIG. 2. It shows the overall concept of the transducer system 13 . The system is comprised of a pair of focused transducers collinearly placed opposite each other and spaced apart such that their focal points 8 coincide or are near to each other. They will be placed on the opposite sides of the tooth 40 to be examined. There needs to be a coupling agent or device present between the tooth 40 and the transducers. Each transducer would have handling device 2 attached to help position it.
[0072] The third embodiment of the present invention is shown in FIG. 3. It shows the overall concept of the transducer system 13 . The system is comprised of a pair of transducers placed opposite each other and in approximation to the tooth 40 to be examined. There needs to be a coupling agent or device present between the tooth 40 and the transducers. These transducers would have a connecting bridge 5 between the transducers to maintain their alignment. There could be handling device 2 attached to the arrangement of transducer system and/or connecting bridge 5 for help in positioning.
[0073] The fourth embodiment of the present invention is shown in FIG. 4. It shows the overall concept of the transducer system 13 . The system is comprised of a pair of focused transducers collinearly placed opposite each other and spaced apart such that their focal points 8 coincide or are near to each other. They will be placed on the opposite sides of the tooth 40 to be examined. There needs to be a coupling agent or device present between the tooth 40 and the transducers. These transducers would have a connecting bridge 5 between the transducers to maintain their alignment. There could be handling device 4 attached to the arrangement of transducer system and/or connecting bridge 5 for help in positioning.
[0074] The fifth embodiment of the present invention is shown in FIG. 5. It shows the overall concept of the transducer system 14 . The system is comprised of a horizontal array of transducers placed opposite each other and in approximation to the tooth 40 to be examined. The arrays can be planar or curvilinear. If they are planar they should be opposite across the tooth 40 . If they are curvilinear they should be on the same horizontal plane across the tooth 40 . There needs to be a coupling agent or device present between the tooth 40 and the transducers. These transducers would have a connecting bridge 5 between the transducers to maintain their alignment. There could be handling device 4 attached to the arrangement of transducer system and/or connecting bridge 5 for help in positioning.
[0075] The sixth embodiment of the present invention is shown in FIG. 6. It shows the overall concept of the transducer system 14 . The system is comprised of a horizontal array of focused transducers collinearly placed opposite each other and spaced apart such that their focal points 8 coincide or are near to each other. They will be placed on the opposite sides of the tooth 40 to be examined. The arrays can be planar or curvilinear. If they are planar they should be opposite across the tooth 40 . If they are curvilinear they should be on the same horizontal plane across the tooth 40 . There needs to be a coupling agent or device present between the tooth 40 and the transducers. These transducers would have a connecting bridge 5 between the transducers to maintain their alignment. There could be handling device 4 attached to the arrangement of transducer system and/or connecting bridge 5 for help in positioning.
[0076] The seventh embodiment of the present invention is shown in FIG. 7. It shows the overall concept of the transducer system 15 . The system is comprised of a vertical array of transducers placed opposite each other and in approximation to the tooth 40 to be examined. The arrays can be planar or curvilinear. If they are planar they should be opposite across the tooth 40 . If they are curvilinear they should be on the same vertical plane across the tooth 40 . There needs to be a coupling agent or device present between the tooth 40 and the transducers. These transducers would have a connecting bridge 5 between the transducers to maintain their alignment. There could be handling device 4 attached to the arrangement of transducer system and/or connecting bridge 5 for help in positioning.
[0077] The eighth embodiment of the present invention is shown in FIG. 8. It shows the overall concept of the transducer system 15 . The system is comprised of a vertical array of focused transducers collinearly placed opposite each other and spaced apart such that their focal points 8 coincide or are near to each other. They will be placed on the opposite sides of the tooth 40 to be examined. The arrays can be planar or curvilinear. If they are planar they should be opposite across the tooth 40 . If they are curvilinear they should be on the same vertical plane across the tooth 40 . There needs to be a coupling agent or device present between the tooth 40 and the transducers. These transducers would have a connecting bridge 5 between the transducers to maintain their alignment. There could be handling device 4 attached to the arrangement of transducer system and/or connecting bridge 5 for help in positioning.
[0078] The ninth embodiment of the present invention is shown in FIG. 9. It shows the overall concept of the transducer system 16 . The system is comprised of a horizontal and vertical array of transducers placed opposite each other and in approximation to the tooth 40 to be examined. The arrays can be planar or curvilinear. If they are planar they should be opposite across the tooth 40 . If they are curvilinear they should be on the same horizontal and vertical planes across the tooth 40 . There needs to be a coupling agent or device present between the tooth 40 and the transducers. These transducers would have a connecting bridge 5 between the transducers to maintain their alignment. There could be handling device 4 attached to the arrangement of transducer system and/or connecting bridge 5 for help in positioning.
[0079] The tenth embodiment of the present invention is shown in FIG. 10. It shows the overall concept of the transducer system 13 . The system is comprised of a horizontal and vertical array of focused transducers collinearly placed opposite each other and spaced apart such that their focal points 8 coincide or are near to each other. They will be placed on the opposite sides of the tooth 40 to be examined. The arrays can be planar or curvilinear. If they are planar they should be opposite across the tooth 40 . If they are curvilinear they should be on the same horizontal and vertical planes across the tooth 40 . There needs to be a coupling agent or device present between the tooth 40 and the transducers. These transducers would have a connecting bridge 5 between the transducers to maintain their alignment. There could be handling device 4 attached to the arrangement of transducer system and/or connecting bridge 5 for help in positioning.
[0080] In the preferred embodiment FIG. 11 shows a transducer system 13 may be interconnected to peripheral electronic and/or electrical components. This illustrates schematically one example of the relationship between said transducer system 13 and peripheral components for at least some of the corresponding embodiments of said transducer system 13 . A pulser (signal generator) 21 producing a suitable electronic ultrasonic pulse is electrically connected to the transmitting transducer that is then able to impart ultrasonic stress waves through the tooth 40 as hereinbefore described. Stress waves received by the receiving transducer are converted into corresponding electrical signals that are then amplified and processed in a processor (receiver) 22 .
[0081] Peripheral electronic means such as an oscilloscope 25 can be used with the processor 22 and may be used for displaying the profile of said stress waves received by said the receiving transducer 13 in a manner known in the art. Said electrical signals may also be connected to an electronic computer 31 for further analysis. The said oscilloscope 25 may typically display a receive pulse waveform (FIG. 15). The receive pulse waveform represented by the transmission time displayed on the oscilloscope 25 is formed of many parts. Transmission time is the time it takes for the stress (acoustic) wave to travel from the transmitting transducer to the receiving transducer. Due to the complex paths the stress wave can take through the various structures of the tooth 40 , there is a transmission time for every possible path. The shortest path in time is not necessarily the shortest path in space. The stress wave may travel further in a higher velocity enamel layer and yet arrive sooner than the wave that travels a shorter path through the lower velocity dentine layer. Due to the many possible paths through the tooth 40 , the stress wave transmitted by the transmit transducer will result in many waves, separated in time, at the receive transducer. For our purposes, transmission time represents the time it takes for the first stress wave to reach the transducer. This time represents the shorted stress (acoustic) path in time through the tooth 40 . Each time the transducer system is moved, either manually, mechanically the transmission time displayed on the oscilloscope 25 will be different. With suitable analysis, a system will be able to identify dental lesions 41 and other defects by analyzing the different transmission times and the resulting waveforms. The received stress wave electrical signals may also be channeled to an electronic recording or storage device 26 for further analysis. If a electronic recording or storage device 26 is used there will be either pushbuttons 28 on the handling device 2 , 4 or footswitches 29 for the transducer system that will signal the computer 31 when to record 26 the received stress wave waveform so it can be processed and/or be viewed or printed 27 latter.
[0082] We propose the use of two classes of arrays of stress (acoustic) transducers. The first class represents one-dimensional arrays 14 - 15 where the transducers are arranged in either a straight line (a linear array) on a curved line (curvilinear array). The second class represents two-dimensional arrays 16 where the transducers are arranged on either a flat rectilinear grid or on a curved grid.
[0083] A phased array is an array of transducers and electronic circuitry that produce a focused receive and/or transmit stress (acoustic) beam. In transmit, the electronic signals input into each transmit transducer is timed such that the resulting stress (acoustic) wave from each respective transducer will converge at a point in front of the array (the transmit focus). In receive, the electronic signals from each receive transducer is delayed such that the sum of all the delayed signals is a single signal that is maximized only when the stress (acoustic) energy emanates from a point front of the array (receive focus). By suitable timing and delay, the transmit and receive signals can be moved in a plane containing the receive and transmit arrays. Thus, the point of maximum stress (acoustic energy) and maximum stress (acoustic) sensitivity can be electronically translated laterally along the arrays, axis and in range in front of the arrays. For our purposes, overlapping the transmit and receive focus of the opposed receive and transmit arrays insures that the maximum signal will be that set of paths which travel trough the combined focus. This limits the spatial location of these paths, which, in turn, aids in the spatial location of any defect (e.g. dental caries) in the tooth 40 . Both one-dimensional and two-dimensional arrays can be setup as phased arrays.
[0084] In another preferred embodiment FIG. 12 shows an array transducer system 14 , 15 , embodiment five through eight, may be networked to peripheral electronic and/or electrical components. This illustrates schematically one example of the relationship between said array transducer system 14 , 15 and peripheral components for at least some of the corresponding embodiments of said transducer system 14 , 15 . A pulser (signal generator) 21 producing a suitable electronic ultrasonic stress wave is electrically interconnected to the transmitting transducer that is then able to impart ultrasonic stress waves through the tooth 40 as hereinbefore described. Stress waves are received by one or more receiving transducers in the array on the opposite side of the tooth 40 . If a single receiving transducer is selected to receive the stress wave it can be any in the set of receiving transducers in the receiving array. Each transducer in the receiving array is treated as a separate channel and will have its own peripheral electronic and/or electrical components or a separate channel in the associated peripheral electronic and/or electrical components. Stress waves received by the receiving transducer are converted into corresponding electrical signals that are then amplified and processed in a processor 22 .
[0085] Peripheral electronic means such as an oscilloscope 25 can be operatively networked to the processor 22 and may be used for displaying the profile of said stress waves received by said the receiving transducer 14 in a manner known in the art. Said electrical signals may also be channeled to an electronic computer 31 for further analysis. For each receive channel the said oscilloscope 25 may typically display a receive pulse waveform (FIG. 15). The receive pulse waveform represented by the transmission time displayed on the oscilloscope 25 is formed of many parts. Transmission time is the time it takes for the stress (acoustic) wave to travel from the transmitting transducer to the receiving transducer. Due to the complex paths the stress wave can take through the various structures of the tooth 40 , there is a transmission time for every possible path. The shortest path in time is not necessarily the shortest path in space. The stress wave may travel further in a higher velocity enamel layer and yet arrive sooner than the wave that travels a shorter path through the lower velocity dentine layer. Due to the many possible paths through the tooth 40 , the stress wave transmitted by the transmit transducer will result in many waves, separated in time, at the receive transducer. For our purposes, transmission time represents the time it takes for the first stress wave to reach the transducer. This time represents the shorted stress (acoustic) path in time through the tooth 40 . Each time the transducer system is moved, either manually, mechanically the transmission time displayed on the oscilloscope 25 will be different. With suitable analysis, a system will be able to identify dental lesions 41 and other defects by analyzing the different transmission times and the resulting waveforms. The received stress wave electrical signals may also be channeled to an electronic computer 31 for further analysis. If a computer 31 is used there will be either pushbuttons 29 on the handling device 2 , 4 or footswitches 28 for the transducer system that will signal the computer 31 when to record 26 the received stress wave waveform so it can be processed and/or be viewed or printed 27 latter. This system can be further enhanced by processing the information from all the receive transducers in the receive array for each transmit pulse to show the tomography of each structure or layer in the tooth 40 .
[0086] When a horizontal or vertical array transducer system 14 , 15 is used the transducer system will have to be moved (translated), either mechanically, this could be done by a motorized system using stepping motors or gear motors or electrically as in a phased array, after the stress wave pulse information is viewed or recorded.
[0087] For a horizontal array transducer system 14 will be moved vertically on the tooth 40 . Typically the horizontal array transducer system 14 will be placed near the top of the crown for the first reading. Once the tooth 40 is viewed or recorded the horizontal array transducer system 14 will be moved towards the gum line 45 a set amount and the process will be repeated. It can be repeated clear down onto the gum 45 itself. This process will be continued until the whole area to be surveyed is covered. If the only area of concern is the gum 45 area it would be possible to do a survey of that area alone. By using a digital oscilloscope 25 and saving waveforms it is possible to view and compare each slice of the tooth 40 recorded this way. From this information it is possible to diagnose secondary lesions and other defects in a tooth 40 or under a gold crown 42 . It is also possible to diagnose gingivitis and other periodontal diseases.
[0088] For a vertical array transducer system 15 will be moved horizontally across the tooth 40 . Typically the vertical array transducer system 15 will be placed vertically at one side of the tooth 40 with one pair of opposing transducers near the top of the crown for the first reading. Once the tooth 40 is viewed or recorded the vertical array transducer system 15 will be moved towards the other side of the tooth 40 in a set amount and the process will be repeated until the whole tooth 40 is surveyed. The vertical array transducer system can be placed on the gum 45 if that area is the only point of interest. By using a digital oscilloscope 25 and saving images it is possible to view and compare each slice of the tooth 40 recorded this way. From this information it is possible to diagnose secondary lesions and other defects in a tooth 40 or under a gold crown 42 . It is also possible to diagnose gingivitis and other periodontal.
[0089] When there is a horizontal and vertical array transducer system 16 it is possible, as is the art, to have a representation displayed on the monitor 34 , without the need for mechanical translation, showing the tooth 40 as a whole as well as a representation of all its interior structures shown in different colors to include all dental lesions 41 and other defects. When the horizontal and vertical array transducer system 16 is placed over the tooth 40 to be diagnosed and its related gum tissue the image produced will allow for the diagnoses of secondary lesions and other defects in a tooth 40 or under a gold crown 42 as well as of gingivitis and other periodontal diseases will be seen plainly. Depending on the design of the horizontal and vertical array transducer system 16 it might be necessary to move it in set amount to get a total picture with separate images being, as is the art, “stitched” together.
[0090] [0090]FIG. 13 illustrates in detail a picture of a tooth 40 with a gold crown 42 with dental lesions 41 under the crown and a periodontal pocket 43 and interfaces that can be shown and/or mapped by the invention.
[0091] [0091]FIG. 14 illustrates in detail a section of a dentition comprising a number of adjacent teeth with surface dental lesions 41 and interproximal dental lesions 41 that can be shown and/or mapped by the invention.
[0092] The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.
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A method and device using stress waves for dental examination. According to the method, the dental structure (such as a tooth) under examination is subjected to a stress (acoustic) wave. The stress wave propagates through the dental structure and is received on the other side. From the analysis of the transmission time and/or the resulting waveform, diagnostic information results as to the presence of dental disease such as dental caries that may be present on the tooth surface under dental restorations such as fillings or metal crowns. According to the invention, the stress wave is generated by a suitable transducer, coupled to the dental structure through a transmission medium, propagates through the dental structure, coupled through another transmission medium, received by a acousto-electric transducer, and analyzed by suitable electronic means.
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BACKGROUND
1. Field of the Invention
The present invention relates to chemotactic chambers, i.e., to chambers for measuring the effect of concentration gradients of mobile chemicals upon the directional response of biological cells. More specifically, the present invention relates to chemotaxis test sites comprising top and bottom regions separated by one or more membrane filters.
2. Background of the Invention
Chemotaxis is the directional response of biological cells or organisms to concentration gradients of mobile chemicals. Conventional chemotactic chambers comprise two compartments separated by a filter, with one or both of the compartments open to air. Cells in suspension are placed in the upper compartment, and a chemotactic factor or control is placed in the bottom compartment. The chemotactic factor can be used in various dilutions to get a dose-response curve. The controls are generally of two kinds: negative, when the same medium is used to suspend the cells above and below the filter; and chemokinetic, when a chemotactic factor is placed in the same concentration in the medium with the cells and on the opposite side of the filter. Chemokinetic controls allow the user to distinguish heightened random activity of the cells, due to contact with the chemotactic factor, from directional response in a concentration gradient of the chemotactic factor.
Chemotactic activity is measured by first establishing a stable concentration gradient in the chemotactic chamber. The chamber is incubated for a predetermined time, then the filter is removed from the apparatus. The cells that have migrated through the filter (or into the filter to a certain depth) are then counted. A comparison is then made between the activity of the cells in a concentration gradient of the chemotactic factor being tested, and the activity of the cells in the absence of the concentration gradient.
The apparatus can also be used to measure the response of cells of different origins--e.g., immune cells from patients suffering from diseases--to a chemotactic factor of known chemotactic activity. In this case the cells in question are challenged by both a negative control and the chemotactic factor to see if the differential response is depressed or normal.
Microchemotaxis chambers and some of their applications are described in Falk et al., "A 48 Well Micro Chemotaxis Assembly for Rapid and Accurate Measurement of Leukocyte Migration," Journal of Immunological Methods, 33, 239-247 (1980); Harvath et al., "Rapid Quantification of Neutrophil Chemotaxis: Use of a Polyvinylpyrrolidone-free Polycarbonate Membrane in a Multiwell Assembly," Journal of Immunological Methods, 37, 39-45 (1980); Richards et al., "A Modified Microchamber Method for Chemotaxis and Chemokinesis," Immunological Communications, 13 (1), 49-62 (1984); Falk et al., "Only the Chemotactic Subpopulation of Human Blood Monocytes Expresses Receptors for the Chemotactic Peptide N-Formylmethionyl-Leucyl-Phenylalanine," Infection and Immunity, 36, 450-454 (1982); and Harvath et al., "Two Neutrophil Populations in Human Blood with Different Chemotactic Activities: Separation and Chemoattractant Binding," Infection and Immunity, 36 (2), 443-449 (1982), all of which are hereby expressly incorporated by reference herein.
SUMMARY OF THE INVENTION
The present invention is a multiple-site chemotactic test apparatus comprising a membrane filter having areas which hold the fluid on the top and bottom of the filter by surface tension.
In some embodiments of the present invention, the membrane filter is a capillary pore membrane. The pores in the capillary pore membrane filter are between 0.1 and 14 micrometers in diameter, depending on the type of cell which is being used in the assay, and the nature of the assay. For example, a 0.1 or 0.2 micrometer pore size can be used to allow the pseudopods of certain cells (e.g., cancer cells) to penetrate the membrane in response to a chemotactic factor, but preclude the cell bodies from getting through the membrane. The differential response is then measured by determining how much the pseudopods protrude in stimulated as opposed to unstimulated "wells." However, if very large cells are used, and the assay is read by counting migrated cells, then the pores must be large enough for those cells to migrate through the pores.
Initially, the fluid on top of the filter is comprised of cells suspended in media (i.e., cells in a balanced salt and nutrient solution), and the fluid on the bottom of the filter is either just media (a negative control) or a solution of chemotactic factor and media. Chemokinetic controls, however, contain the same concentration of chemotactic factor above and below the filter (i.e., chemokinetic controls differ from the chemotaxis test sites because there is no gradient in the concentration of the chemotactic factor). In its simplest form, the test apparatus consists of a sheet of membrane filter, typically 6 to 30 micrometers thick, attached to a rigid frame. The pores in the membrane are usually chosen to be between 2 and 14 micrometers. However, when cell bodies must be prevented from migrating, smaller pore sizes are used. Drops of chemotactic factor and drops of control are placed on one side of the filter in a well-defined pattern, e.g., 96 spots, 9 mm apart in a 12×8 array. The filter and frame are then turned over, and drops of a cell suspension are pipetted onto the other side, on spots corresponding to the initial placement of the chemotactic factors and controls. The drops can range in volume from 2 to 75 μ l. The drops of fluid are held in place by surface tension. Gravity induces top-to-bottom flow after fluid is placed on both sides of the filter until the surface tension forces equal the gravitational forces. The fluid on both sides of the filter is held in place by capillary action and surface tension. The apparatus is then incubated at 37°±1° C., for periods ranging from 15 minutes to 72 hours.
When the filter and the frame are removed from the incubator, several different protocols can be followed, depending on whether one or two filters are employed, and what type or types of filters are used. One protocol appropriate to an apparatus comprising a single capillary pore membrane filter is to remove the cells from the non-migrated side of the filter and then fix, stain and count the cells that have migrated through the filter. Another protocol is to fix all the cells and then count the ones that have migrated. The migrated cells are counted on the bottom side of each exposed filter area and a comparison is made between the activity of the cells exposed to the chemotactic factor and the activity of the cells exposed to the controls. If a non-capillary pore membrane is used, such as a cellulose nitrate filter, then the distance the cells have travelled into the filter matrix, i.e., the distance between the leading front of migrating cells in the filter matrix and their starting point on the surface of the filter is measured. If two filters are used, the top filter is discarded and the cells on the bottom filter are counted. Cells can also be labelled with a radioisotope such as Cr 51 , and then the amount of radioactivity can be measured at each site of the bottom filter, after discarding the top filter.
Many different stains and staining techniques can be used, including, for example, fluorescent stains.
Further embodiments of the invention discussed herein incorporate features for stabilizing concentration gradients at the sites where chemotactic factors or controls and cell suspensions are placed on the filter by blocking or inhibiting gravity-driven flow of the fluids through the filter at those sites.
A first object of the present invention is to provide a simple apparatus and method for the measurement of the chemotactic activity of a plurality of specimens.
A further object of the present invention is to provide an inexpensive and/or disposable multiple-site chemotactic test apparatus.
A still further object of the present invention is to provide a multiple-site chemotactic test apparatus requiring very small volumes of cell suspension for the precise measurement of chemotactic factor activity.
An additional object of the present invention is to provide a high sensitivity multiple-site chemotactic test apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of a first embodiment of the chemotactic apparatus of the present invention.
FIGS. 2a-2d are enlarged views of a portion of the chemotactic apparatus of the present invention, showing a single chemotaxis test site, at different stages of the procedure.
FIGS. 3a-3d are schematic representations of a second embodiment of the present invention showing the use of a grid positioned below the filter.
FIGS. 4a-4d are schematic representations of a third embodiment of the present invention showing the use of a grid positioned above the filter.
FIGS. 5a-5d are schematic representations of a fourth embodiment of the present invention showing the use of grids positioned both below and above the filter.
FIG. 6 is a schematic representation of a fifth embodiment of the present invention showing an apparatus constructed from two filters bonded to each other with a removable seal.
FIG. 7 is a schematic representation of a sixth embodiment of the present invention that utilizes specially shaped holes in a grid to control gravity flow.
FIGS. 8a-8b are schematic representations of a seventh embodiment of the present invention incorporating specially shaped holes in a grid to control gravity flow.
FIGS. 9a-9b are schematic representations of a ninth embodiment of the present invention incorporating a pressure-sensitive adhesive-backed sheet.
FIGS. 10a-10b are schematic representations of a tenth embodiment of the present invention incorporating a material that blocks fluid flow but allows diffusion of chemotactic factors and migration of cells.
DETAILED DESCRIPTION OF THE INVENTION
In its simplest embodiment, shown in FIG. 1, the multiple-site chemotactic test apparatus 10 of the present invention comprises a membrane filter 11 (e.g., a 10 μm thick polycarbonate capillary pore membrane filter with 5 μm holes manufactured by Poretics or Costar Nuclepore, Pleasanton, Calif.) attached to a rigid frame 12, as shown in FIG. 1. The term "site" is used herein to refer to a delineated spot on a filter where a solution of chemotactic factor or plain media is positioned, and juxtaposed thereto, on the opposite side of the filter, a suspension of cells is positioned, whether these fluids are kept in position by compartments, as in conventional chemotactic chambers, or by surface tension. The position of the chemotaxis test sites is defined by, for example, a pattern 13 on filter 11. The pattern, which identifies the sites of the chemotaxis test sites, may be formed by ink imprinted on the filter, may be a patterned film of plastic or silicone, or it may be defined by a hydrophobic coating silk-screened or otherwise applied to the filter. In this first preferred embodiment of the present invention, the chemotactic fluids are kept in position by surface tension. The frame can be plastic, stainless steel, aluminum, or another suitable material. The frame must be rigid enough to keep the filter and any grids attached thereto flat. The membrane filters can be attached to the frame by any suitable fastening means, including glue, heat seals, ultrasonic seals, or mechanical means.
FIGS. 2a-2d are enlarged views of a portion of the chemotactic apparatus, showing a single chemotaxis test site at successive stages of the procedure. In the embodiment shown in FIGS. 2a-2d, the pattern on filter 11 is formed by hydrophobic coatings 14a on the top side and 14b on the bottom side of filter 11. The hydrophobic coatings cover the entire filter, except at the locations defining the chemotaxis test sites. In this manner, fluid transport through the filter is only possible at these locations. FIG. 2a shows the chemotaxis test site before the addition of any fluids. FIG. 2b shows the chemotaxis test site after the addition of the chemotactic factor or control 15. FIG. 2c shows the chemotaxis test site after it has been turned over, and a cell suspension 16 has been added to the side of filter 11 opposite to the chemotactic factor or control 15, before the fluid has stabilized. FIG. 2d shows the chemotaxis test site after the fluids have stabilized, when the gravitational forces have been equalled by the surface tension forces. In FIG. 2d, the fluid 17 on the bottom side of filter 11 now includes media that has flowed to that side of the filter from the cell suspension on the opposite side.
The apparatus is used according to the following procedure. Drops of various control solutions and drops of chemotactic factor (sometimes at varying concentrations) are placed on one side of the membrane filter in a well-defined pattern delineated by printing on or otherwise applied to the surface of the membrane, or by silk-screening or depositing a coating on the membrane. The coating may simply define the locations of the chemotaxis test sites, or it may also function as a hydrophobic barrier, spatially restricting the chemotactic fluid. The apparatus is then turned over, and the cell suspension is pipetted onto the corresponding spots on the opposite side. In some embodiments, gravity induces flow from the cell-suspension side of the membrane until capillary and other surface tension forces come into equilibrium with the gravitational forces. In other embodiments, surface tension and capillary action forces prevent gravity-induced flow.
The apparatus is then incubated at 37° C. for a predetermined time period, typically in the range of 15 minutes to 72 hours, depending upon the nature of the cells, the membrane filter used, the chemotactic factors being tested, etc. After incubation, cells that have not migrated from the cell-suspension side of the filter are usually removed by one of several techniques including squeegees, wiper blade and cotton swabs. This procedure is repeated after immersing the filter in a phosphate-buffered saline solution between wipings. If a double filter barrier is used, the filter with the non-migrated cells is usually discarded. Sometimes, however, the non-migrated cells are not removed, allowing them to be studied or counted as well as the migrated cells. For example, cells on one side of a polycarbonate capillary pore membrane filter 10 micrometers thick can be examined and counted using confocal microscopy without visual interference by the cells on the opposite side of the membrane.
The cells in or on the filter are then fixed (e.g., for about 2 minutes in methanol) and allowed to dry (sometimes the filter is mounted on a glass slide, and dried). The cells on the mounted filter are then stained, if necessary (e.g., with DiffQuick, manufactured by Harleco, Gibbstown, N.J.). The number of cells that have migrated through or into the filter in each test site are then counted. The cells can be counted individually using a microscope (e.g., with a 25× objective), or the number of cells could be estimated using specialized equipment such as an optical density reader (e.g., a UVmax Model optical density reader manufactured by Molecular Devices, Menlo Park, Calif. or by Optomax Image Analyzer manufactured by Optomax, Inc., Hollis, N.H.). If the cells are labeled with a radioactive isotope, the test sites are separated from each other and counted using a scintillation counter.
When this first embodiment of the apparatus of the present invention is used, obtaining the proper placement of the drops on the membrane filter can be accomplished with a hand-held pipette, an automatic variable-volume pipetter, or by an automatic pipetting machine. As shown in FIG. 1, the spacing and position of the drops of chemotactic fluid, i.e., the position of the individual chemotaxis test sites, is indicated by pattern 13. The position and spacing of the 96 chemotaxis test sites is preferably a standard spacing, e.g., the standard spacing for 96-well microtiter plates, and the outside dimensions of the frame are preferably identical to the dimensions of standard microtiter plates, so that automatic equipment such as the UVmax optical density reader can be used.
In a second preferred embodiment of the present invention, shown schematically in FIGS. 3a-3d, the apparatus also includes a grid 21 containing an array of holes 22. FIG. 3a also shows an optional patterned hydrophobic coating 23 on filter 11. FIG. 3b shows the apparatus after chemotactic factor or control 15 has been added. FIGS. 3c and 3d show the apparatus after it has been turned over, and a cell suspension 16 has been added. FIG. 3c shows the initial disposition of cell suspension 16, and FIG. 3d shown the disposition of cell suspension 16 after it has stabilized, when the gravitational forces are equalled by surface tension forces.
Grid 21 may be manufactured from any rigid or flexible material that is not biologically active or water-soluble, e.g., plastics such as acrylic, polystyrene, polycarbonate, polyethylene, or polypropylene; silicone; or metals such as coated aluminum, steel, or stainless steel. In this embodiment, for example, the holes may be placed in a 9 mm center-to-center pattern composed of 12 rows and 8 columns--the standard microtiter configuration. They may be arranged in any convenient pattern, however, on smaller or larger frames with a greater or lesser number of test sites. For example, when the final counting will be done using a microscope, the test sites could be arranged on a smaller frame, e.g., 2"×3" in a pattern closer than the 9 mm center-to-center pattern of the standard microtiter plate. In this preferred embodiment, the holes can vary in diameter from 0.5 mm to 7 mm. The optimum grid thickness depends upon the diameter of the holes, and the material of the grid. If the grid material is hydrophilic (or possibly if the grid material is neither hydrophilic nor hydrophobic) and the holes are 1 mm in diameter, the grid could be 0.5 mm thick. Capillary forces would then hold a large proportion of the fluid above the filter, as shown in FIG. 3d. If the grid material is hydrophobic, then the fluid may all be forced through the filter, as shown in FIG. 2d. If the wells were 6 mm in diameter and the grid material were hydrophilic or neutral, the grid material should be thicker to hold enough fluid above the filter to allow the concentration gradient of the chemotactic factor to develop.
In a third embodiment of the present invention, shown in FIGS. 4a-4d, filter 11 is attached to the bottom of grid 21. FIG. 4a shows an optional patterned hydrophobic coating 23 on filter 11. FIGS. 4a-4d show the disposition of the chemotactic fluid 15 (FIGS. 4b, 4c and 4d) and cell suspension 16 (FIGS. 4c and 4d). FIG. 4c shows the disposition of the fluids immediately after the cell suspension is added, and FIG. 4d shows the disposition of the fluids after stabilization.
In a fourth embodiment of the present invention, two grids are used, as shown in FIGS. 5a-5d. One grid 21 is attached to the top of filter 11, and one grid 21 is attached to the bottom of filter 11. Chemotactic factors or controls 15 are added to one side of filter 21, as shown in FIG. 5b, and cell suspensions 16 are added to the other side of filter 11, as shown in FIG. 5c. FIG. 5c shows the disposition of the cell suspension initially. FIG. 5d shows the disposition of the fluids after stabilization.
A fifth embodiment of the present invention uses two capillary pore membrane filters 31 and 32, as shown in FIG. 6, or one capillary pore membrane and one non-capillary pore membrane, or two noncapillary pore membranes. Filters 31 and 32 are each permanently bonded to grid 33 and outer frame 34, respectively. Filters 31 and 32 face each other, and are in direct contact with each other. FIG. 6 shows a gap between filters 31 and 32 only to make FIG. 6 more easily understood. The filters are temporarily bonded to each other by means of, for example, a thin pressure sensitive adhesive seal 35. The filters are sealed around each chemotaxis test site where cell suspensions 36, and controls and chemotactic factors 37 are to be positioned.
The chemotactic activity of the chemotactic factors is then determined according to the following procedure. First, the chemotactic apparatus is inverted and chemotactic factors and controls 37 are placed on filter 32 opposite to the openings in grid 33. Second, the apparatus is placed right side up, and cell suspensions 36 are placed on filter 31 within the openings in grid 33. Capillary action will hold most of the fluid in the top compartment, at which point a concentration gradient of the chemotactic factor will be established in those test sites containing chemotactic factors. Third, the apparatus is placed in an incubator. Fourth, the apparatus is removed from the incubator after incubation at about 37° C. for, e.g., 30 minutes to 72 hours. The cells are then fixed, and the top grid and filter are separated from the bottom frame and filter. Fifth, the bottom filter is stained. Finally, the number of cells on the bottom filter is counted.
Depending upon the kind of filter employed for the bottom filter, and on the counting technique (optical, densitometry, etc.) different methods would be used to handle the bottom filter after its separation from the top filter. For example, if a capillary pore polycarbonate filter is to be used, the filters can be separated before or after fixing and the cells and/or cellular debris on the top side of the bottom filter can be removed or not removed. If a standard optical technique is to be used to count the cells attached to the bottom filter, it may be desirable to remove cells and cellular debris from the top surface of the bottom filter. However, that would not be necessary if densitometry is to be used.
A sixth preferred embodiment of the present invention, shown in FIG. 7, uses the same structure as the fifth embodiment, i.e. two membrane filters 41, one mounted on grid 42, the second to frame 34, and attached in direct contact to each other. However, in this embodiment, the holes in the grids are specially shaped to increase the amount of fluid held by capillary action in the top and bottom compartments after fluid stabilization. For example, as shown in FIG. 7, the opening of each hole in grid 42 is relatively narrow, with the diameter of the hole increasing towards filter 41.
A seventh preferred embodiment shown in FIGS. 8a and 8b. This embodiment is similar to the sixth embodiment, but top grid 54 comprises relatively large holes 52, whereas bottom grid 55 comprises numerous smaller holes 56 corresponding to each larger hole 52 in top grid 54. FIG. 8a shows a cross-section of the apparatus viewed from the side. FIG. 8b is a view from the bottom of bottom grid 55, showing the disposition of small diameter holes 56 in bottom grid 55. The small diameter holes provide larger capillary action forces, more effectively counteracting the effect of gravitational forces on the fluids. An alternative to this embodiment comprises one grid with small holes that preclude gravity flow on the chemotactic factor side of the filters (usually the bottom side) and a hydrophobic coating (but no deep grid) on the other side (usually the bottom side). This configuration allows a drop of cell suspension to sit on top of a flat filter and not flow through at all (or very little), so that the concentration gradient is established immediately. Because there is plenty of fluid with the cells, the concentration gradient does not disappear rapidly. Also, the top surface can be easily wiped clean of cells that have not migrated.
An eighth preferred embodiment of the present invention also uses the same structure as the fifth embodiment, i.e., two capillary pore membrane filters mounted on grids and attached in direct contact to each other. In this embodiment, a flexible pressure sensitive sheet is used to seal off one side of a grid after its compartments are filled, or partially filled. The sheet limits gravity-induced flow when fluid is added to the other side of the filter, thus establishing a stable concentration gradient.
A ninth preferred embodiment of the present invention is similar to the eighth embodiment, but uses a single filter, as shown in FIGS. 9a-9b. This embodiment is used by filling the test sites formed by holes 61 in grid 62 with cell suspensions 63. A sheet 64 backed with a pressure sensitive adhesive 65 is applied to the side of grid 62 opposite to filter 66. Excess cell suspension is expressed and trapped in the recesses 67 between the test sites, and the apparatus is inverted. A chemotactic factor 68 is then pipetted onto the opposite side of the filter over each of the wells. The apparatus is then inverted again and incubated. Since the top test sites are sealed, the media in which the cells are suspended cannot flow through the filter upsetting the concentration gradient. Another way to use this apparatus would be to put the chemotactic factor(s) and control(s) in the side to be sealed, then pipette the cell suspension onto the other side.
A tenth preferred embodiment of the present invention, which can use either two filters (as in the eighth preferred embodiment) or a single filter (as in the ninth preferred embodiment) is shown in FIGS. 10a-10b (two filter version). FIG. 10a is a cross-sectional side view of an individual chemotaxis test site. FIG. 10b is a cross-sectional side view of several chemotaxis test sites. FIG. 10a shows a top filter 71 and a bottom filter 72 placed close together facing each other, separated by a small space (5-20 micrometers). The pores of the filter(s) and the space between the filters (if two filters are used) are filled with an occluding material 73 such as agar, matragel (available from Collaborative Research) that will allow diffusion of chemotactic factors 74 and migration of the cells in cell suspension 75, and will not dissolve in media (or will dissolve slowly enough to allow the assay to be completed). The two filters are kept close together by a removable pressure sensitive adhesive 76 that surrounds each well. The assembly is supported by an outer frame 77, as shown in FIG. 10b. The apparatus is similar to the apparatus of the eighth preferred embodiment (if two filters are used) or to the ninth preferred embodiment (if a single filter is used). Gravity does not affect the fluids since the agar (or equivalent occluding material) prevents the vertical flow of the fluids. If two filters are used, capillary pore filters are preferred since melted agarose will flow between the two filters by capillary action, leaving no voids. Horizontal flow is prevented by a relatively hydrophobic coating 78 surrounding each well.
In an eleventh preferred embodiment of the present invention, the two-filter structure disclosed in the fifth embodiment is used, but the pressure-sensitive adhesive is soluble in a solvent such as ethanol that does not dissolve the filters. The two filters could then be easily separated after the apparatus is soaked in, for example, ethanol fixative. Alternatively, the top filter could be made from a material (e.g., cellulose nitrate) that dissolves in a solvent (e.g., ethanol), and the bottom filter could be made from a material (e.g., polycarbonate) that does not dissolve in that solvent. The top filter would then be dissolved in the solvent after the cells are fixed, or during the fixing process. In either alternative, after the bottom filter is separated from the top filter, the bottom filter would be stained and the number of cells on or in the bottom filter would be determined using any of the techniques discussed above.
The foregoing disclosure of embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many variations and modifications of the embodiments described herein will be obvious to one of ordinary skill in the art in light of the above disclosure. The scope of the invention is to be defined only by the claims appended hereto, and by their equivalents.
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A simple chemotactic apparatus and method wherein surface tension is used to hold cell suspensions, chemotactic factors, and control fluids in place on membrane filters. In some embodiments, chemotaxis factors and controls are placed on one side of a membrane filter, and cell suspensions are placed on the other. Gravitational flow is limited by the effect of surface tension on the fluids. In some of the preferred embodiments, grids, sheets, or occluding materials are used to further limit the gravitational fluid flow.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 10/696,970, filed on Oct. 30, 2003, the technical disclosure of which is hereby incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to a method for adhering three-dimensional bits, fragments, chunks, or morsels to a substrate and more particularly, to a method for adhering large three dimensional food bits to a snack food substrate whereby the large bits are substantially adhered to the substrate. More specifically, the present invention relates to a method for making a dual-textured, topped snack food.
2. Description of Related Art
Food particulates are often added to foods, especially snack foods. Tortilla chips, pretzels, crackers, popcorn, and numerous other foodstuffs often have seasonings applied to them during processing. Seasonings used, usually in a powdered form, have included salt, cheese, chili, garlic, Cajun spice, ranch, sour cream and onion, among many others. However, there is often an undesirable accumulation of seasoning on the sidewalls and bottom of the snack food bag with the result that the consumer has less than the desired complement of topping thereon. The separation occurs because of insufficient adhesion of the seasoning to the chip. The problem of separation increases with the size and weight of the individual particles.
One way this problem has been approached in the past was by using oil as an adhesive to adhere particulate seasonings to a base or substrate. For example U.S. Pat. No. 6,534,102 B2, issued to Kazemzadeh, discloses a seasoning bit that, following extrusion and cooking is immersed into an oil and seasoning slurry at an elevated temperature. The product is then dry-coated with seasonings or sprayed with hot or room temperature oils and fats either carrying seasonings or the seasonings are applied as dusting on the surface while the oil and fats are used to adhere the seasoning to the surface. One drawback to using only oil, however, is that the adhesive strength of traditional oil mixes are not strong enough to adhere large three-dimensional bits to a substrate surface. In certain applications, large three-dimensional bits are desirable because they enable packaged snack chips to emulate another topped product including, but not limited to a pizza with toppings, a nacho chip, or a tostada.
Another prior art composition used to adhere particulate to a food product is U.S. Pat. No. 3,689,290 issued to Blackenstock et al which discloses using a coating agent comprised of dry corn syrup solids to adhere small particle sizes of food toppings to a substrate. The Blackenstock Patent discloses a particle size of the food topping as being 12–100 mesh, which corresponds to a particle size range of 0.150 to 1.68 millimeters (0.0059 to 0.0661 inches). Again, these are relatively small particle sizes that are being adhered to a substrate. The adhesive is not strong enough to adhere a substantial amount of larger three-dimensional particles to the chip.
U.S. Patent Application 2002/0187220 A1 discloses an edible particulate adhesive comprising maltodextrin, an edible surfactant, a solvent, a polysaccharide, and a modified starch. The invention, however, is clearly aimed at very small particulate adhesion. The invention indicates the preferred particle size is less than 650 micrometers. Thus, this invention also fails to adhere relatively large bits to a chip.
Another prior art composition used to adhere flavorings to a foodstuff is illustrated by European Patent EP 0 815 741 A2 which discloses a hot melt composition comprising a starch, such as corn syrup, maltodextrin, or an amylase-treated starch, and a plasticizer, such as a polyol or a polyacetic acid. Like the other inventions, this invention was also designed to adhere powdery-type particulate additives to foodstuffs such as salt, sugar, cheese powder, and ranch seasonings. Like other inventions in the prior art, it also fails to adhere relatively large bits to chips.
Another prior art approach to adhere large food flavorings and spices was to put the flavorings on an unbaked cracker. Thus, cheese flavorings and other spices were then baked into the dough. This approach, however, cannot be used when it is desirable to adhere particles to a substantially cooked snack piece, such as a tortilla chip, immediately prior to the addition of seasoning.
Consequently a need exists for a method to adhere large particulate flavoring bits, fragments, chunks, or morsels to a food substrate. The method should allow a snack food to demonstrate the characteristic look, texture, and taste of an emulated topped food product, yet be highly resistant to separation. The method should be adaptable to a product line wherein the addition of the large particles occurs at a step after substantial cooking of the underlying food substrate.
Food ingredients are typically enclosed in a hermetically sealed food package and thus approach equilibrium with the relative humidity of the inside of the package. It has proven difficult to achieve a dual-textured or multi-textured snack food, because the food ingredient having a lower moisture content and thereby crispy texture, typically absorbs evaporated moisture from a food ingredient having a higher moisture content and thereby softer texture.
As the lower moisture content food ingredient absorbs water it becomes less crispy. As the higher moisture content food ingredient loses water, it hardens. Because of this moisture migration it is difficult to achieve a long shelf-life on dual textured snack products.
The water content of a food ingredient is typically measured by its water activity level (“Aw”). The Aw is defined by the following equation:
Aw=P/Po
where P=vapor pressure of water in the food Po=vapor pressure of pure water under the same conditions.
The Aw is a quantitative measure of unbound free water in a system that is available to support biological and chemical reactions. Two different food ingredients with the same water content can vary significantly in their Aw level depending on how much free water is in the system. If a higher moisture content, soft texture ingredient has an Aw that exceeds the relative humidity of its environment, then water tends to evaporate from the food ingredient causing the ingredient to harden. Similarly, if a lower moisture content, crispy texture has an Aw that is less than the relative humidity of its environment, then it tends to absorb water, causing the ingredient to soften. For example, consider a piece of soft cheese, having an Aw of 0.92 placed on a crispy cracker having an Aw of 0.10 in a sealed container initially at 50% relative humidity. Over time the texture of the soft cheese hardens as it loses water and approaches equilibrium with the container atmosphere. The texture of the crispy cracker, however, softens as it absorbs this evaporated moisture to approach equilibrium with the container atmosphere. As a result, both food ingredients lose their desired texture. Moreover, besides texture changes, changes in moisture can lead to other undesirable effects including microbial growth, degradation reactions, and organoleptical changes.
The problem is compounded in multi-textured, topped food products that require an adhesive. Water-based adhesive systems utilized on a food substrate negatively impact texture as hydration and subsequent thermal drying destroy internal structures. Moreover, a water-based adhesive deteriorates chip crispness, especially if applied in an aqueous state, because of moisture migration from the adhesive into the food substrate. In addition, there is flavor loss that results from drying a moistened food substrate. As discussed previously, oil-based adhesives fail to adhere large bit particulate flavoring bits to a food substrate. As a result, it has long been difficult for food product manufacturers to package multi-textured food products for extended shelf life storage. Numerous attempts to preserve dual-textured features of food products are illustrated in the prior art.
U.S. Pat. No. 4,401,681 discloses a method for preventing moisture migration from a high-moisture phase to a low-moisture phase. For example, the patent discloses combining corn syrup solids having a Dextrose Equivalent of 22 to 24 and a high methoxyl pectin with a pizza sauce to prevent moisture from the sauce from migrating into the pizza crust during shelf life. This disclosure, however fails to teach a method that minimizes moisture transmission from a softer texture to a crisper texture through an area having a headspace. Rather the disclosure is limited to providing a direct barrier layer between two ingredients with high differential moisture contents.
U.S. Pat. No. 4,853,236 discloses a shelf-stable dual-textured food product having a first, hard texture comprising a fruit composition on a shell portion, and a second, variably textured core portion comprising an oil-in-water emulsion. This disclosure fails to teach both an outer chewy and an outer crispy texture of a topped food product.
U.S. Pat. No. 4,961,942, discloses a dough composition having a plurality of shelf-stable textures. The patent further discloses a soft, chewy filler cookie dough and a firmer outer casing dough wherein the casing dough comprises a high sugar content. It fails to disclose a dough that can be used in savory snacks.
U.S. Pat. No. 4,913,919, assigned to the same assignee of the present application, discloses a coating composition comprising a high solids content aqueous suspension, having a solids content of at least 40% by weight. The outside surface of a snack food is coated with the aqueous solution. The coating is dried to provide a crisp outer texture and chewy inner texture. This disclosure fails to teach an outer chewy texture.
U.S. Pat. No. 5,405,625, discloses a cheese filled snack product having a crisp outer casing comprising potato flakes and pre-gelatinized rice flour. In one embodiment, the filling is moist and the snack food product can be baked or microwaved without the cheese filling over expanding or leaking. This disclosure fails to teach an outer chewy texture.
U.S. Pat. No. 6,500,474 discloses using a heated liquid coating to further coat a pre-coated food product and subsequently contacting the liquid-coated pre-coated food piece with a chunky particulate matter to form a food product enrobed with a substantially continuous chunky coating. This disclosure fails to teach an outer crispy texture.
Accordingly, a need exists for a method for making a shelf-stable dual-textured, topped snack food product comprising a crisp food substrate and a chewy topping. The method should utilize a non-water based and non-oil based adhesive that can adhere large particulate flavoring bits to a substantially cooked, crisp food substrate. The method should minimize the water activity in food product ingredients and should minimize moisture migration from the chewy topping to the crisp food substrate.
SUMMARY OF THE INVENTION
The proposed invention uses a combination of dry-powdered adhesives admixed onto bits and placed on a food substrate and wherein further the adhesive undergoes a glass transition and flows down around the bit to the bit and food substrate contact point. Subsequently, process conditions change, and the adhesive undergoes another glass transition back to an amorphous solid which hardens the adhesive and adheres the bit to the food substrate surface.
Hence, this invention produces a method whereby large flavoring bits are adhered to a snack food substrate to achieve the look, texture, and taste of an emulated topped food product. In addition, the instant method provides a topping that is highly resistant to separation. Furthermore, the method can be implemented following the cooking of the underlying food substrate.
The invention further provides a method that minimizes moisture migration from a softer textured topping to a crispier food substrate. Food product ingredient properties are optimized to provide at least two distinct textures. Optimized food product ingredient properties can be moisture content, water activities, and sorption slopes.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:
FIG. 1 is a schematic representation of one embodiment of the new process.
FIG. 2 is a graph representation depicting moisture sorption isotherms for the major ingredients in one embodiment of the invention.
DETAILED DESCRIPTION
An embodiment of the innovative invention will now be described with reference to FIG. 1 . Seasoning, flavoring or illustrative bits 12 and an adhesive 14 are mixed together in a 30-inch diameter mixer or tumbler 10 . As used herein, large seasoning bits 12 are food grade seasonings wherein at least 5% of the bits, by weight, have a diameter exceeding 1.7 millimeters and are substantially between 1.7 and 17.0 millimeters diameter. In a preferred embodiment, vegetable oil 16 , preferably at a temperature of about 23 to 32° C. (74 to 90° F.), is sprayed into the tumbler 10 to coat the seasoning bits 12 to function as a temporary liquid adhesive 16 and promote bonding between the dry adhesive 14 and the seasoning bits 12 . In an alternative embodiment, the temporary liquid adhesive 16 is heated to a temperature of about 43 to 60° C. (109 to 140° F.) prior to being sprayed in the tumbler 10 . The temporary adhesive 16 used can be any prior art adhesive oil including, but not limited to, olestra®, corn oil, soybean oil, cottonseed oil, or palm oil. Alternatively, an oil substitute can be used as a temporary liquid adhesive 16 . The objective is to coat the seasoning bits 12 to promote bonding with the dry adhesive 14 during mixing and until the dry adhesive 14 undergoes a glass transition phase. Any temporary liquid adhesive 16 that meets this objective can be used. Examples of an oil substitute that could be used as a temporary adhesive includes, but is not limited to glycerol, propylene glycol, alcohol, and mixtures thereof. A temporary liquid adhesive 16 may not be needed if the particle size of the dry adhesive 14 is small enough, and/or the individual bits 12 are porous enough, and/or the bit has a moist hydroscopic or oily exterior.
The tumbler 10 is a cylindrical device that rotates and is typically used to add seasoning to a substrate's total circumference. In this invention, however, the tumbler is used to admix adhesive 14 to the seasoning bit 12 . Thus, although a tumbler 10 is described in this embodiment, any equivalent device including but not limited to, a mixer, a tumbler including a batch tumbler or a continuous tumbler, or a blender such as a batch blender, continuous blender, or ribbon blender may be used to admix the adhesive 14 to the seasoning bit. As used in this invention, a substrate is substantially cooked and can be a fried or baked snack food chip made from a dough, such as masa or other starch based dough. As used in this invention the terms substrate and chip are used interchangeably and refer to any wide variety of snack food items that are commonly commercially available including, but not limited to, potato chips, crackers, multigrain chips, corn chips, and tortilla chips. In one embodiment of the present invention, the substrate comprises a first texture that is crispy.
Seasoning bits 12 comprising Textured Vegetable Protein, flavored vegetable bits, or colored bits are commercially available. For example, Bac'n Pieces™ Bacon Flavored Bits can be purchased from McCormick® of Sparks, Md. in many local grocery stores. The bits can also comprise corn flour or wheat flour, independently or in combination. Hence, the bits can consist of textured vegetable protein, corn flour, wheat flour, and combinations thereof. In one embodiment, the bits have a moisture content preferably less than about 5%.
Following admixing in the tumbler 10 , the seasoning bits 12 and adhesive 14 are then transferred 22 to a first topping unit 20 . A topping unit 20 manufactured by Raque, of Louisville, Ky. can be used. Corn Syrup Solids are defined by the FDA as dried glucose syrups in which the reducing sugar content is 20 Dextrose Equivalent or higher. In one embodiment, the dry adhesive 14 used preferably comprises corn syrup solids with a Dextrose Equivalent more than 20 and most preferably between about 20 and 50. This Dextrose Equivalent range can result in reduced chewiness, shininess, and sweetness. Dextrose Equivalents higher than about 50 can be used, but result in a sweeter, as opposed to savory flavor. Numerous other carbohydrate adhesives can also be used including, but not limited to dextrose, dextrin, maltodextrose, sucrose, polydextrose, and combinations thereof. These carbohydrates can be purchased from various suppliers including National Starch and Chemical Company of Bridgewater, N.J., Danisco Cultor of New Century, Kans., and Tate & Lyle PLC located in London, England. In an alternative embodiment, maltodextrin, defined by the FDA as dried glucose syrups in which the reducing sugar content is less than 20 Dextrose Equivalent can be used. Use of maltodextrin, however, can require the use of steam to activate the adhesive. By using corn syrup solids instead of a water-based or steam requiring adhesive, a crisp chip texture is preserved because hydration and subsequent thermal drying is greatly reduced. Thus, use of corn syrup solids or other acceptable carbohydrate results in a preferable dry adhesive application.
Again, although this invention is described with reference to a fried tortilla chip, any food substrate including, but not limited to, a chip, a cracker, a baked chip, an extruded snack, or a puffed snack, can be used. Prior to the chip entering the fryer 30 , the dough is made by any one of a number of standard methods well known in the art. A novel and unique combination of modifications, however, can be made to the prior art dough and/or the dough ingredients to enhance the crispiness of the underlying topped substrate. For example, in a tortilla chip embodiment, a coarser corn grind, preferably made from the corn mill having a gap between about 0.0020 and about 0.0030 millimeters, and more preferably having a gap between about 0.0023 and about 0.0026 millimeters can be used. A coarser grind requires less shear when corn is ground into masa, decreasing the amount of starch gelatinization and increasing the amount of larger ground corn particles in the masa. Larger particles cause the chip texture to remain more coarse which conveys a heartier, crunchier, and crispier chip. Less gelatinization provides thinner surface film formation during frying. In addition, larger ground corn particle sizes cause more disruptions, even more so in a thinner surface film. When the dough is fried, water within the dough can more easily escape through these disruptions as steam, resulting in a chip with a lower moisture content. A lower moisture content chip results in a crispier texture. Further, the product will contain less steam build-up within the chip during frying, which in turn reduces the amount and size of surface blisters produced, further resulting in a crispier texture. Starch, preferably between about 2% and about 10% by weight of the dough, can be added to the dough to absorb more water during masa production. In one embodiment, waxy corn starch is used. Again, when this water is subsequently released during frying, smaller and more numerous surface blisters are created resulting in a crisper texture. A low gluten flour, preferably between about 2% and about 35% by weight of the dough, can be used in the dough for organoleptic properties. In one embodiment, wheat flour is used.
Typically, a dough product is compressed between a pair of counter rotating sheeter rollers that are located closely together, thereby providing a pinch point through which the dough is formed into sheets. The dough can then be cut by, for example, a cutting roller to form the shape of the product desired. Alternatively, the dough or masa is extruded and cut into a desired chip shape. After the dough or masa is cut, the chips are transported towards and through a toast oven. The chips should be toasted to achieve a pre-cook moisture content between about 22% and about 30%. For this, the chips are deposited onto a moving belt. After toasting, the shaped chips have increased stiffness for insertion into a fryer 30 . In one embodiment, the toasted chips, prior to being fried, are passed through a proofing stage where the chips are exposed to ambient air for a specified amount of time to equilibrate moisture. After proofing, chips are transferred to a fryer 30 . To convey the chips into the fryer 30 , the chips are removed from the toasting belt or conveyor and placed onto the fryer conveyer 32 . Because flat substrate facilitates even application of the seasoning bits 12 , in the preferred embodiment, a monolayer fryer 30 is utilized to help ensure a flat substrate and minimize chip curl. The monolayer fryer 30 has two belts; an upper belt and a lower belt. The substrate is positioned between the two belts as it moves through the fryer 30 . The two-belt system minimizes chip curl and keeps the chip flat as it moves through the fryer. The chip, in the example of a tortilla chip, is in the monolayer fryer for a dwell time of about 52 to 56 seconds at a temperature of about 170–207° C. (338–404° F.). A monolayer fryer also provides for more uniform frying and thus allows the chips to produce consistent blisters and a more uniform, lower exit moisture content. As used herein, an exit moisture content is the moisture content following the cooking of the food substrate. In one embodiment, the exit moisture content of a chip fried in a monolayer is preferably between about 0.5 and about 1.0%. Batch frying, on the other hand, results in variable moisture content, blister formation and finished oil contents. Moreover, prior art exit moisture contents typically exceed 1.0%. A lower exit moisture content results in a crispier chip. In addition, a drier, lower moisture content chip comprises more surface oil than interior oil. This surface oil helps to protect the chips from absorbing excess moisture during the topping process (discussed below). In an alternative embodiment, any fryer 30 known in the art can be used. After exiting the fryer 30 , the substrate proceeds along an open mesh conveyer belt 42 and cools to approximately 100 ° F. to 150° F. Because this temperature is still above ambient, moisture migration onto the chip substrate is retarded. Although numerous modifications are disclosed to illustrate a preferred embodiment, the essence of the invention can be achieved with fewer than all of the dough ingredient and processing modifications disclosed, as those skilled in the art are likely to recognize. After the chip has been fried, the seasoning bits 12 and adhesive 14 are then applied 24 to the chip via a topping unit 20 or other topping means.
The chip is then sent to a first oven 40 . An impingement oven such as model IMDJ-45AS-1, manufactured by Heat and Control, Inc., of Hayward, Calif. can be used as the first oven. The chip is transported through the first oven 40 on an open mesh conveyer belt for approximately 17 seconds. The elevated oven temperature, preferably about 190 to 232° C. (374 to 450° F.), serves to trigger the glass transition phase of the dry adhesive 14 onto the substrate. In one embodiment, steam 44 between 6.9 and 34.5 kPa (1 and 5 psi) is injected into the first oven 40 to expedite activation of the dry adhesive 14 by lowering the glass transition temperature of the adhesive via the addition of water vapor. In this embodiment, the chip then proceeds out of the first oven 40 along the open mesh conveyer belt 52 into a second oven 50 to drive off the moisture added in the first oven as steam. In the second oven 50 , the chip proceeds on an open mesh conveyer belt for approximately 17 seconds at an elevated temperature range of about 190 to 232° C. (374 to 450° F.). The second oven 50 can be a make and model identical to the first oven 40 .
In an alternative embodiment, only one oven, without steam, is used to trigger the glass transition phase of the dry adhesive. In such an embodiment, the oven temperature remains the same about 190 to 232° C. (374 to 450° F.). In addition, the total dwell time also remains the same at about 34 seconds. In alternative embodiments, longer or shorter dwell times and higher or lower temperatures could be used. The dwell time and temperature need only be sufficient to promote a glass transition change in the dry adhesive 14 . An AirForce® impingement oven, manufactured by Heat & Control, Inc. of Hayward, Calif. can be used as in the single-oven embodiment. As used herein, an adhering means for adhering a seasoning bit to a substrate is meant to include any edible carbohydrate blend that undergoes a glass transition change at an adhesive (as opposed to oven) temperature between 40 and 60° C. when the adhesive has a moisture content of between about 4 to 8%. As those skilled in the art are aware, the glass transition temperature range of the dry adhesive 14 changes relative to the moisture content. The higher the moisture content, the lower the glass transition temperature range. Conversely, the lower the moisture content, the higher the glass transition temperature range. Thus, if the moisture content of the adhesive is raised above or below 4 to 8%, then the corresponding glass transition temperature range will change as well. However, such changes should be construed to be within the spirit and scope of the claimed invention.
The chip then proceeds out of the second oven 50 along the open mesh conveyer belt 72 where it begins to cool. In one embodiment, the chip cools for approximately 30 seconds. The dry adhesive 14 hardens on cooling to affect a strong bond between the seasoning bits 12 topping and the substrate.
In one embodiment, the steps of adding and heating the seasoning bits 12 above the glass transition temperature of the dry adhesive 14 and then allowing the seasoning bit 12 , adhesive 14 , and substrate to cool below the adhesive's 14 glass transition temperature could be repeated to form a multi-layered chip. By repeating these steps, two or more layers of seasoning bits 12 could be added to a single substrate or chip.
In a preferred embodiment of the invention, a second topping, preferably, but not necessarily, in the form of cheese shreds, a cheese-like topping, or a cheese topping is then applied to the bit-topped substrate via a second topping unit 60 . Unlike the first topping comprising the bits, the second topping has a lower melting temperature than the seasoning bits 12 of the first topping and no additional adhesive is required to adhere the second topping to the substrate. In one embodiment, the second topping having a second texture comprises a softer texture than the first texture of the crispy substrate. A shelf-stable cheese analog as disclosed in U.S. patent application Ser. No. 10/649,825 and assigned to Kerry Specialty Ingredients of Beloit, Wis. can be used as the second topping.
FIG. 2 is a graph representation depicting the moisture sorption or desorption isotherms for the major ingredients in one embodiment of the invention. A moisture sorption isotherm is a graphical representation of the relationship between the moisture content of a food ingredient that absorbs moisture and the Aw of that food ingredient at a particular, constant temperature. The x-axis represents the Aw and the y-axis represents the moisture percentage of the main food components. An example of a chip moisture sorption isotherm 202 and adhesive sorption isotherm 204 is depicted in FIG. 2 . A desorption isotherm is a graphical representation of the relationship between the moisture content of a food ingredient that loses moisture and the Aw of that food ingredient at a particular, constant temperature. A shelf-stable cheese analog moisture desorption isotherm 206 is depicted in FIG. 2 . As used herein, sorption slope is defined as the slope of the sorption or desorption curve of a particular water activity value. The steeper the sorption slope, the higher the propensity to absorb water. Conversely, the more level the slope, the lower the propensity of a food ingredient to absorb water. Thus, it is advantageous for the chewy, softer texture food ingredients to comprise a steeper sorption slope than the crispy food ingredients to control moisture migration. For example, in one embodiment, the adhesive sorption slope 204 is steeper than the chip sorption slope 202 . Because of the adhesive's steeper sorption slope 204 , the adhesive helps buffer moisture uptake by the substrate. Hence, in one embodiment, the crispy chip substrate sorption slope 206 is always less steep than the cheese sorption slope 202 and often less steep than the adhesive sorption slope 204 .
The second topping cheese analog comprises a fresh Aw between about 0.40 and about 0.50 and a heated Aw between about 0.30 and about 0.40 and comprises a desorption slope steeper than the sorption slope of the crispy base as illustrated by FIG. 2 . A fresh Aw is the Aw of the cheese prior to the cheese being melted. The heated Aw is the Aw of the cheese after the cheese has been melted on the crispy substrate (discussed below). Moreover, at least one humectant can be used in the second topping to further inhibit moisture migration from the second, soft topping. A humectant is an ingredient that promotes the absorption and retention of moisture. Humetectants that can be used include, but are not limited to, glycerin, propylene glycol, sodium lactate and sodium acetate. In addition, other water binding systems such as cellulose can also be used in the second topping. The second topping can comprise at least one humectant between about 10 percent to about 40 percent, cellulose between about 1 percent to about 5 percent, or combinations thereof based on the weight of the second topping.
Referring back to FIG. 1 , the second topping unit 60 can be the same model and type as first topping unit 20 . Following application of the second topping, the chip is then routed to a third oven 70 . The third oven 70 is preferably an infrared Raymax 1525, manufactured by Watlow Electric Manufacturing Company, of St. Louis, Mo. The chip is routed to a third oven 70 on an open mesh conveyer belt 72 . The chip proceeds through the third oven 70 for a dwell time of approximately 60 seconds with an oven temperature about 82 to 138° C. (180 to 280° F.). In alternative embodiments, shorter or longer dwell times and higher or lower temperatures could be used. The dwell time and temperature need only be sufficient to melt the second set of toppings. The chip then proceeds out of the third oven 70 on an open mesh conveyer belt 92 where it is sprayed with an atomized oil or other liquid adhesive from both the top and the bottom. Unlike the temporary adhesive 16 , the objective with this liquid adhesive is to provide a more permanent adhesive to bind a seasoning with the chip and the toppings. An oil spray applicator 80 manufactured by GOE-Avins of Amherst, N.Y., model #OSM-5000-BP-3065 can be used. Although many types of liquid adhesives including lard, other animal-based oils, and vegetable-based oils can be used as the atomized spray, a preferred embodiment uses corn or soybean oil. The liquid adhesive or oil should be sprayed at an elevated temperature, preferably about 43 to 60° C. (109 to 140° F.). Following oil atomization, the chip passes through a seasoning applicator 90 where a particulate flavored seasoning 94 is applied to both sides of the chip. The seasoning applicator 90 first applies seasoning 94 to the topside of the chip on an open mesh conveyer belt. The chip is then flipped onto another open mesh conveyer belt and the other side is then seasoned. A seasoning applicator manufactured by ARBO of Toronto, Ontario, Canada model number KDC-VV 12″×20″×45″ can be used. The chip may then be further cooled and sent to be packaged 96 .
While this invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.
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Method for making a dual-textured food substrate having large seasoning bits whereby the bits are substantially adhered to the food substrate, or chip. A first topping comprising large seasoning bits and a dry adhesive is applied to a cooked chip having a first texture. The topped, cooked chip is then heated to a temperature such that the dry adhesive undergoes a glass transition and flows down around the bit to the bit and food substrate contact point. The topped, cooked chip is then subjected to changed process conditions, such as cooling, the adhesive hardens, and a bond is formed between the chip and the seasoning bits. A second topping having a second texture is then placed and melted onto the chip. The food ingredient properties are optimized to provide a shelf-stable dual-textured food product.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to an anchoring system for nucleic acid molecules. The anchoring system generally comprises a solid support and a chemical linking moiety useful for ether formation with another chemical moiety on a nucleic acid molecule. The present invention further contemplates methods for anchoring a nucleic acid molecule to a solid support via a covalent linkage. The anchoring system of the present invention is useful inter alia in construction of nucleic acid arrays, to purify nucleic acid molecules and to anchor nucleic acid molecules so that they can be used as templates for in vitro transcription and/or translation experiments and to participate in amplification reactions. The present invention is particularly adaptable for use with microspheres and the preparation of microsphere suspension arrays and optical fiber arrays. The anchoring system permits the generation of an anchored oligonucleotide for use as a universal nucleic acid conjugation substrate for any nucleic acid molecule or population of nucleic acid molecules. The present invention further provides a kit useful for anchoring nucleic acid molecules or comprising nucleic acid molecules already anchored to a solid support.
[0003] 2. Description of the Prior Art
[0004] Reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that this prior art forms part of the common general knowledge in any country.
[0005] The increasing sophistication of recombinant DNA technology is greatly facilitating research and development in a range of biotechnology-related industries.
[0006] Many manipulations involving nucleic acid molecules require immobilization strategies. One immobilization strategy involves the use of binding partners such as avidin and streptavidin. Whilst the latter system has been successfully employed in many nucleic acid anchoring systems, it does have some limitations and does not enable the full gamut of nucleic acid manipulations now available to be performed on single and mixtures of nucleic acid molecules. It is also subject to non-specific binding thus limiting the accuracy of any immobilization reactions.
[0007] In addition, there are difficulties in using linker systems like streptavidin and avidin in automated and high throughput systems.
[0008] The immobilization procedure can be complex and involve the use of expensive reagents. There is a need, therefore, to develop a universal conjugation system for nucleic acid molecules.
[0009] In accordance with the present invention, a universal conjugation system has been developed for anchoring nucleic acid molecules to a solid support. The system of the present invention has a myriad of uses in molecular biology including micro or macro nucleic acid arrays, capturing, purifying and/or sorting nucleic acid molecules, RNA production for RNAi and short, interfering RNA (si-RNA) applications and microsphere nucleic acid technology, especially for microengineered structures and nanoshells. The system may also be usefully employed in high throughput and/or automated systems. In particular, the present invention provides a re-usable anchoring system for nucleic acid molecules.
SUMMARY OF THE INVENTION
[0010] Throughout this specification, unless the context requires otherwise, the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element or integer or group of elements or integers but not the exclusion of any other element or integer or group of elements or integers.
[0011] Nucleotide and amino acid sequences are referred to by a sequence identifier number (SEQ ID NO:). The SEQ ID NOs: correspond numerically to the sequence identifiers <400>1 (SEQ ID NO:1), <400>2 (SEQ ID NO:2), etc. A summary of the sequence identifiers is provided in Table 1. A sequence listing is provided after the claims.
[0012] The present invention provides a conjugation system for target nucleic acid molecules. The conjugation system facilitates immobilization or anchoring of the target nucleic acid molecules to a solid phase. The solid phase may be any form of solid support including microspheres, microchips, beads, slides such as glass slides, microliter wells and dipsticks amongst many others.
[0013] The solid support is generally selected on the basis of ease of manipulation, inexpensiveness, thermal stability and stability to aqueous and/or organic solvents.
[0014] Silica and methacrylate microspheres are particularly useful especially for use in suspension arrays or optical fiber arrays.
[0015] The solid support is generally modified to include a chemical moiety capable of engaging in the formation of a covalent bond with another chemical moiety present on a nucleic acid molecule (the tag oligonucleotide). Any number of chemical moieties may be employed on the solid support but in a preferred embodiment, the solid support comprises a thiolated surface capable of engaging in covalent bond formation with an acryl group linked to the 5′ end of a tag oligonucleotide via a spacer between the 5′ base of the oligonucleotide and the active group. One preferred form of anchoring system is shown in FIG. 1 .
[0016] The level of success in anchoring the tag oligonucleotide to the solid support is measured by annealing an oligonucleotide which is complementary to the tag oligonucleotide (referred to herein as the “α-tag”) optionally labeled with a reporter molecule such as but not limited to 6-FAM. The annealing of the α-tag results, in a preferred embodiment, in a 3′ single-stranded overhang (or “sticky end”) comprising the tag oligonucleotide.
[0017] Any target nucleic acid molecule is then ligated to the tag oligonucleotide via a bridging oligonucleotide. The bridging oligonucleotide comprises a sequence of nucleotides complementary to a nucleotide sequence of the 3′ overhang portion of the tag oligonucleotide and a sequence of oligonucleotides complementary to a 5′ end portion of a target nucleic acid molecule.
[0018] Accordingly, a target nucleic acid conjugating system is provided comprising a solid support having a tag oligonucleotide covalently bound to the surface of the solid support, the tag oligonucleotide rendered partially double-stranded by annealing an α-tag oligonucleotide to the tag oligonucleotide to provide a 3′ overhang single-stranded portion of the tag oligonucleotide to which is annealed a bridging oligonucleotide having a nucleotide sequence capable of hybridizing to the 5′ end portion of a target nucleic acid molecule. Conveniently, the bridging oligo is removed from the support prior to becoming active.
[0019] In one embodiment, therefore, the present invention provides a universal nucleic acid anchoring system comprising the structure:—
[0000] S(-T) p
[0000] wherein:
S is a solid support having a chemical moiety capable of covalent bond formation with a second chemical moiety; T is a tag oligonucleotide comprising single-stranded DNA having said second chemical moiety linked via a spacer molecule to its 5′ end, said spacer comprising mc+n atoms, having from about 1 to about 100 atoms, where m is the number of repeats of a small subunit, c is the number of atoms in each repeat, and n is the number of atoms not in the repeat; said T further comprising a bridging oligonucleotide having a nucleotide sequence complementary to 3′ overhang nucleotides on the tag oligonucleotide and a further nucleotide sequence complementary to a nucleotide sequence on a 5′ end of a target nucleic acid molecule; wherein T may be represented p times on the solid support wherein p is from about 1 to about 100,000.
[0023] In the above structure, the line “-” represents a covalent bond between a solid support surface chemical moiety and the chemical moiety on the tag oligonucleotide.
[0024] The universal anchoring system of the present invention permits the generation of arrays of nucleic acid molecules. When the solid support comprises microspheres, the present invention permits the generation of suspension arrays. The anchored nucleic acid molecules may be subject to, for example, mutation identification or other manipulations such as in vitro transcription and/or translation reactions.
[0025] The nucleic acid anchoring system, i.e. S(-T) p , may be re-used and, hence, only a single anchoring reaction need take place for virtually unlimited customizations via specific targets and bridges
[0026] The present invention further contemplates a method for anchoring a target nucleic acid to a substrate, said substrate comprising:—
(i) a solid support having a surface chemical moiety; (ii) a tag oligonucleotide having a chemical moiety linked to its 5′ end via a spacer comprising a molecule with mc+n atoms wherein m is the number of repeats of a small subunit and c is the number of atoms in each repeat and n is the number of atoms not in the repeat wherein the latter chemical moiety is in covalent bond formation with the chemical moiety on the surface of the solid support; (iii) a complementary (α) tag oligonucleotide sequence which has hybridized to said tag oligonucleotide sequence such that there is a single-stranded nucleotide sequence constituting a 3′ overhang of the tag oligonucleotide; (iv) a bridging oligonucleotide having a complementary nucleotide sequence to the nucleotide sequence of the 3′ overhang portion of the tag oligonucleotide and which bridging oligonucleotide has hybridized to its complementary sequence on the tag oligonucleotide leaving a single-stranded portion of the bridging oligonucleotide which has a complementary nucleotide sequence to the 5′ terminal portion of said target nucleic acid molecule;
wherein said method comprises contacting said target nucleic acid molecule to said substrate for a time and under conditions to permit hybridization of the 5′ portion of the nucleic acid molecule to the single-stranded portion of the bridging oligonucleotide and permitting ligase-mediated covalent bond formation between said target nucleic acid molecule and the substrate.
[0031] A spacer generally but not necessarily comprise carbon and oxygen based molecules or is a hydrocarbon molecule such as having from about 1 to about 100 atoms, more preferably from about 18 to about 50 atoms and even more preferably from about 24 to about 36 atoms is particularly useful.
[0032] The spacer molecule is conveniently an alkyl, alkenyl or an alkynyl molecule including a hydrocarbon molecule. Preferably, the spacer is a linear non-branched hydrocarbon although many other molecules may be employed such as ethylene oxy (PEG) or one or more amino acids to separate the oligonucleotide from the surface of the solid support as long as they are inert in terms of the constructs intended application.
[0033] A summary of sequence identifiers used throughout the subject specification is provided in Table 1.
[0000]
TABLE 1
Summary of sequence identifiers
SEQUENCE
ID NO:
DESCRIPTION
1
nucleotide sequence of 5′-acrydite universal tag
2
nucleotide sequence of PO4 complementary tag
3
nucleotide sequence of bridge oligonucleotide
4
nucleotide sequence of PO4 target
5
nucleotide sequence of a target synthesized with 5′
PO4
6
nucleotide sequence of a terminal T3 polymerase signal
sequence
7
nucleotide sequence of target DNA sequence
8
nucleotide sequence of 5′ overhang of common sequence
of bridge
9
nucleotide sequence of common sequence of bridge
10
nucleotide sequence of a tag sequence (FIG. 3A)
11
nucleotide sequence of an α-tag sequence (FIG. 3B)
[0034] A list of terms used herein is provided in Table 2.
[0000]
TABLE 2
Terms
TERM
DESCRPTION
tag oligonucleotide or tag
oligonucleotide molecule anchored to a solid
support face via a covalent bond between a
chemical moiety on the surface of the solid
support and a chemical moiety conjugated to
the oligonucleotide via a spacer molecule
α-tag
oligonucleotide molecule comprising a
nucleotide sequence complementary to the tag
oligonucleotide sequence
solid support
form of solid phase; includes microspheres,
microchips, beads and slides
bridging oligonucleotide
oligonucleotide which bridges the tag
oligonucleotide and the target nucleic acid
molecule; the bridging oligonucleotide has a
nucleotide sequence complementary to a 3′
nucleotide sequence on tag and an end portion
of the target nucleic acid molecule
spacer
a molecule comprising a number of atoms and
having the structure mc + n wherein m is the
number of repeats, and c is the number of
atoms in each repeat and n is the number of
atoms not in the repeat
target nucleic acid
DNA or RNA target having a single-stranded
molecule
end portion complementary to part of the
bridging oligonucleotide
anchoring/anchored
joining of two molecules via a covalent
linkage
chemical moiety
a chemical group capable of forming a
covalent bond with another chemical moiety
BRIEF DESCRIPTION OF THE FIGURES
[0035] FIG. 1 is a diagrammatic representation of the three component linker used to modify thiolated solid phase, especially silica microsphere activated by silanization with 3-mercaptopropyl trimethoxysilane. AU components are synthesized using standard phosphoramidite coupling chemistry. (A) Reactive group; (B) Spacer (18 atom spacer, with m=6; c=3 and n=2 following designation of mc+n atoms in the spacer; (C) Tag DNA sequence. This component is variable and can be engineered for specific application; (D) Complete Tag Linker. This component serves the purpose of separating the DNA of interest (referred to as Target DNA in text) from the surface as well as provides a method for amplification of Target after molecular testing.
[0036] FIG. 2 is a representation of the process of two-step bead activation with silane to produce a surface with a high density of exposed thiol groups to create a tagged microsphere. Step (1): Raw silica beads are reacted with sulfur containing silane (3-Mercaptoprophyl trimethoxysilane (HS—CH 2 —CH 2 —CH 2 —Si(Ome 3 )). Step (2): Activated beads with dense blanket of surface thiols are reacted with Tag linker (see FIG. 1 ) to produce a bead with many thousands of covalently bound uni-directionally tethered DNA molecules.
[0037] FIG. 3 is a diagrammatic representation showing testing of conjugation efficiency. (A) Immobilized tag sequence; (B) α-tag: reverse complement to tag with 3′ FAM label; (C) approx. 10 4 untreated silica microspheres probed with 10 pMol α-tag; (D) approx. 10 4 activated beads probed with 10 pMol α-tag; (E) approx. 10 4 beads with immobilized Tags probed with 10 pMol α-tag. Fluorescence calculated on Becton-Dickinson FacsCalibur.
[0038] FIG. 4 is a diagrammatic representation showing ligase-mediated customization Phosphorylated target DNA and bridge DNA is mixed with tagged microspheres, T4 DNA ligase, and ATP. After brief reaction at room temperature, bridge and unincorporated targets are removed by heat and separation from the microspheres.
[0039] FIG. 5 is a graphical representation showing testing of ligation efficiency by the use of OLIGREEN (registered trademark). Customized beads (Tag+Target; M2 or left-most peak) and tagged beads (Tag only/no target; M1 or right-most peak) were stained with a small amount of OLIGREEN (registered trademark). Beads were run on Becton Dickinson FacsCalibur flow cytometer. Ligation efficiency is measured by testing the ratio of M2 (tagged+target)/M1 (tag only). For this example, M2/M1 is approximately 2.5, indicative of a successful ligation. M2/M1 values of <1.7 generally represent ligation efficiency of less than 80% of target DNA modified.
[0040] FIG. 6 is a graphical representation of optimal overhang length for ligase-mediated conjugation to tagged microspheres. Bridge oligonucleotides differing by only the number of 5′ bases in direct base pairing with target were tested by OLIGREEN (registered trademark) ligation assay (see FIG. 5 ). (A) 4 base pair overlap; (B) five base pair overlap; (C) six base pair overlap. M1 or Marker 1 is the mean fluorescence of the tagged microsphere. M2 is the mean fluorescence of the tagged microsphere post ligation of target. The quantity M2/M1 measures the relative gain in fluorescence and thus the amount of bound DNA. In this example, five and six base overlaps have greater ligation efficiency than four base overlap.
[0041] FIG. 7 is a graphical representation showing universal binding analogs for general use bridges in ligation-mediated conjugation of tagged microspheres. All bridges had a common sequence of 5′- CXXXXXT [SEQ ID NO:8] CAT AGC TGT CCT-3′ [SEQ ID NO:9]. The 3′ italicized 12 bases were common to, all bridges and hybridized to the 3′ 12 bases of the immobilized tag. The underlined sequence CXXXXXT [SEQ ID NO:8} represents the variable 5′ overhang which hybridized to the target sequence. The Xs represent nucleotide positions which were variable in this test between the actual base and inosines, which are general binding base analogs. FIG. 7A represents the unsubstituted bridge. FIGS. 7B-E represent increasing numbers of inosines in the bridges. A box in the left side of each figure gives the tested sequence of the 5′ overhang. In each experiment, 1×10 5 beads with immobilized tags were reacted with 2.0 nMols of target oligonucleotide and appropriate bridge as well as 20 units T4 DNA ligase, 1 mM ATP, 10 mM MgCl 2 . Reactions were carried out at room temperature for 15 minutes. Unligated DNAs were removed by two 0.2 M NaOH washes. Beads with ligase mediated conjugated products were assayed by OLIGREEN (registered trademark) binding assay using Becton Dickinson FacsCalibur. Ligation efficiency is calculated as the sample fluorescence post binding (M2) divided by the control mean fluorescence (M1). At least 200 events for each data point were collected.
[0042] FIG. 8 is a diagrammatic representation showing use of ligase-mediated customized silica microspheres in solid phase PCR. This experiment is divided into three sections. (A) description of the regions of the DNA to be amplified with labeled probes and their targets; (B) Controls to assess pre-PCR presence of immobilized sequences; (C) Post-PCR probes of amplified sequences.
DETAILED DESCRIPTION OF THE INVENTION
[0043] The present invention provides a nucleic acid anchoring system which facilitates ligase-mediated conjugation of a target nucleic acid molecule to a solid support via a tag oligonucleotide which is conjugated to the solid support via a covalent bond between a chemical moiety resident on the solid support and another chemical moiety on the tag nucleic acid molecule.
[0044] A first aspect of the present invention, therefore, is a tag oligonucleotide anchored to a solid support.
[0045] Accordingly, one aspect of the present invention provides a solid phase comprising a surface with a first chemical moiety capable of participating in covalent bond formation with a second chemical moiety conjugated to a tag oligonucleotide wherein the tag oligonucleotide is a substrate for ligase-mediated covalent bonding to a target nucleic acid molecule.
[0046] In one embodiment, the chemical moiety on the surface of the solid phase is capable of covalent bond formation with a tag-associated amine group, thiol group or acryl group.
[0047] Accordingly, another aspect of the present invention is directed to a solid phase comprising a surface with a first chemical moiety selected from a carboxyl group, an amine group, and a thiol group, said first chemical moiety capable of participating in covalent bond formation with a second chemical moiety selected from an amine group, a thiol group and an acryl group conjugated to an oligonucleotide with the proviso that when the solid phase surface moiety is a carboxyl group then the covalent bond forms with an amine group, when the surface moiety is a thiol group the tag associated moiety is an acryl group or thiol group, or amine group linked via a heterobifunctional linker. The present invention extends, however, to chemical moieties capable of any form of covalent bond formation with any other chemical entity.
[0048] In one preferred embodiment, the chemical moiety on the surface of the solid phase is a carboxyl group and such a group is capable of covalent bond formation with a number of chemical moieties but especially an amine group and when the solid phase chemical moiety is an amine group or a thiol group several methods employing heterobifunctional crosslinkers allow covalent bond formation with an aminated or thiolated tag oligonucleotide.
[0049] Accordingly, another aspect of the present invention is directed to a solid phase comprising either a surface carboxyl group capable of participating in covalent bond formation with an amine group, or a surface encoded amine or thiol group conjugated to a tag oligonucleotide via a crosslinker.
[0050] In a most preferred embodiment, the solid phase surface chemical moiety is a thiol group.
[0051] Most preferably, the chemical moiety conjugated to the tag oligonucleotide is an acryl group.
[0052] In this embodiment of the present invention, there is provided a solid phase comprising a surface thiol group capable of participating in covalent bond formation with an acryl group conjugated to a tag oligonucleotide.
[0053] The solid phase is preferably in the form of a solid support such as a microsphere, bead, glass, ceramic or plastic slide, a dipstick or the wall of a vessel such as a microtiter well. The form of the solid support is not critical and may vary depending on the application intended. However, microspheres such as silica or methacrylate microspheres are particularly useful in the practice of the present invention, especially for use in suspension arrays or optical fiber arrays.
[0054] The selection of solid supports is conveniently based on ease of manipulation, level of expense, thermal stability and/or stability in aqueous and/or organic solvents.
[0055] In a particularly preferred embodiment, therefore, the present invention is directed to microspheres having a thiolated surface capable of participating in linker mediated or direct covalent bond formation with a chemical moiety selected from an amine group, a thiol group and an acryl group conjugated to a tag oligonucleotide.
[0056] Generally, any number of chemical moieties may be present or exposed on the surface of the solid support and these may range from a few hundred to several thousand.
[0057] In a particularly preferred embodiment, there are from about 1 to about 100,000 surface chemical moieties potentially involved in covalent bonding per solid support. This is particularly the case when the solid support is a microsphere. Conveniently, the microsphere comprises from about 500 to about 80000 or more conveniently from about 1000 to about 80000 chemical moieties per bead. Examples include 1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, 11000, 12000, 13000, 14000, 15000, 16000, 17000, 18000, 19000, 20000, 21000, 22000, 23000, 24000, 25000, 26000, 27000, 28000, 29000, 30000, 31000, 32000, 33000, 34000, 35000, 36000, 37000, 38000, 39000, 40000, 41000, 42000, 43000, 44000, 45000, 46000, 47000, 48000, 49000, 50000, 51000, 52000, 53000, 54000, 55000, 56000, 57000, 58000, 59000, 60000, 61000, 62000, 63000, 64000, 65000, 66000, 67000, 68000, 69000, 70000, 71000, 72000, 73000, 74000, 75000, 76000, 77000, 78000, 79000 or 80000.
[0058] In relation to one preferred embodiment, therefore, the present invention provides microspheres each comprising from about 3000 to about 80000 such as about 4000 to about 80000 or more particularly about 50000 to about 80000 surface thiol groups per microsphere.
[0059] The tag oligonucleotide having the chemical moiety capable of covalent bond formation with the solid phase surface chemical moiety may comprise any nucleotide sequence although the nucleotide sequence would generally be known. One particularly useful sequence is an RNA polymerase promoter nucleotide sequence such as the T3 RNA polymerase promoter nucleotide sequence. The benefit of the latter in terms of linking DNA is the ability to generate RNA transcripts. However, any oligonucleotide of known sequence may be employed. The term “oligonucleotide” is not to be viewed to any limiting extent and may comprise from about 10 base pairs (bp) to hundreds of bp.
[0060] It is convenient to ensure that after binding of the tag oligonucleotide to the solid phase that the tag oligonucleotide does not exhibit interference with the solid support surface. Consequently, a spacer molecule is generally included between the chemical moiety and the 5′ end of the tag oligonucleotide. A spacer generally but not necessarily comprise carbon and oxygen based molecules or is a hydrocarbon molecule such as having from about 1 to about 100 atoms, more preferably from about 18 to about 50 atoms and even more preferably from about 24 to about 36 atoms is particularly useful. Examples of the number of atoms in the spacer include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 or 100.
[0061] The spacer may also be multiple repeats such as 2×(18 atoms) spacers or 3×(6 atoms) spacers. The length of the spacer is not critical for most applications as long as a crucial distance threshold between the bead surface and the active end of the DNA tag is maintained.
[0062] Consequently, another aspect of the present invention contemplates an isolated tag oligonucleotide comprising a chemical moiety capable of covalent bond formation with a chemical moiety on the surface of a solid phase, said first mentioned chemical moiety conjugated to said tag oligonucleotide via a spacer molecule having mc+n atoms wherein m is the number of repeats, c is the length of the repeat and n is the number of atoms of the spacer molecule not contained in repeats.
[0063] Generally, m is from about 1 to about 12 such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 and n is preferably 1 or from 0 to about 10 such as 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.
[0064] Conveniently, mc+n is from about 1 to about 100 such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 or 100. Advantageously, the atoms are carbon or oxygen atoms.
[0065] The spacer molecule is conveniently an alkyl, alkenyl or an alkynyl molecule including a hydrocarbon molecule. Preferably, the spacer is a linear non-branched hydrocarbon although many other molecules may be employed such as ethylene oxy (PEG) or one or more amino acids to separate the oligonucleotide from the surface of the solid support as long as they are inert in terms of the constructs intended application.
[0066] The 5′ tag oligonucleotide chemical moiety is conveniently an amine group, a thiol group or an acryl group if the solid support surface chemical moiety is a thiol group.
[0067] In a most preferred embodiment, the 5′ chemical moiety on the tag oligonucleotide is an acryl group.
[0068] In accordance with the above aspect of the present invention, the solid support is preferably a microsphere although any solid support may be employed.
[0069] Accordingly, another aspect of the present invention provides a solid phase comprising a tag oligonucleotide anchored to the surface of said solid phase via a covalent bond between a chemical moiety on the surface of the solid phase and a chemical moiety conjugated to said tag oligonucleotide via a multi atom spacer having the structure mc+n wherein m is the number of repeats, c is the size of the repeat, and n is the number of atoms not included in the repeats.
[0070] As indicated above, mc+n is from about 1 to about 100.
[0071] As indicated above, the covalent bond is conveniently a thiol group covalently bonded to an acryl group or covalently bridged through bifunctional linkers to tag encoded amines or thiols. Furthermore, the spacer molecule is preferably from about 1 to about 100 carbon atoms in length.
[0072] Consequently, another aspect of the present invention comprises an article of manufacture having the structure:—
[0000] S-(mc+n)-[x 1 x 2 . . . x p ]
[0000] wherein:
S is a solid support; m is the number of repeats; c is a repeat of size c; n is the number of atoms not included in repeats; and [x 1 x 2 . . . x p ] is a nucleotide sequence of nucleotides x 1 x 2 . . . x p wherein each of x 1 x 2 . . . x p may be the same or different and the nucleotide length, p, is from 5 to about 200.
[0078] In the above formation, the schematic “-” represents a covalent bond such as, for example, an amide bond or a thioether bond.
[0079] The oligonucleotide sequence, i.e. x 1 x 2 . . . x p is any known sequence such as the T3 RNA polymerase promoter. The oligonucleotide sequence may also comprise an additional nucleotide sequence having, for example, translation start signals, ribosome binding sites and an initiating methionine (ATG) triplet.
[0080] It is particularly convenient to ensure or to measure successful covalent attachment of the tag oligonucleotide sequence to the solid phase. This can be accomplished by incorporating an internal fluor within the tag oligonucleotide sequence. This would give an immediate and simple test of amount of binding. However, this approach is operationally limiting because in most instances, the internal fluor confounds future applications by either interfering with data readout or by interfering by inhibiting the chemistry of the anchored system.
[0081] A preferred approach to measurement of amount of conjugated tag oligonucleotide is to prepare a labeled reverse complement to the tag oligonucleotide. Conveniently, the labeled oligonucleotide sequence is complementary to the 5′ end of the anchored tag oligonucleotide sequence. The label may be any suitable label such as 6-FAM. The 5′ end is generally phosphorylated.
[0082] Accordingly, another aspect of the present invention provides a solid phase comprising a tag oligonucleotide of known sequence anchored thereto via a covalent linkage between a chemical moiety on the surface of the solid phase and a chemical moiety conjugated to the tag oligonucleotide via a molecule of mc+n atoms wherein m is the number of repeated atoms, c is the number of atoms in a repeat and n is the number of atoms not in the repeat and wherein mc+n is from about 1 to about 100, said solid phase further comprising a second oligonucleotide sequence annealed by base pairing to a complementary nucleotide sequence on said first mentioned tag oligonucleotides resulting in an overhang at the 3 end of either the tag oligonucleotide or its complementary oligonucleotide.
[0083] Preferably, the second oligonucleotide sequence comprises a label and is used to measure the success or otherwise of the covalent anchoring of the first oligonucleotide sequence to the solid phase.
[0084] The preferred label is 6-FAM.
[0085] Preferably, the first oligonucleotide sequence overhangs at its 3′ end over the second oligonucleotide sequence.
[0086] As indicated above, the second oligonucleotide is labeled and, hence, it becomes a convenient assay for the success or otherwise of covalent attachment of the first oligonucleotide to the solid phase. One skilled in the art will immediately recognize that there are many variations in order to determine the extent of covalent linkage and that the present invention should not be only limited to one particular means.
[0087] The essence of this aspect of the invention is a solid phase having a first tag oligonucleotide attached thereto via covalent linkage between a first chemical moiety on the surface of the solid phase (e.g. a carboxyl group) and a second chemical moiety conjugated to the first oligonucleotide via a spacer molecule of length mc+n atoms as defined above and a second tag oligonucleotide, optionally labeled with a reporter molecule capable of giving an identifiable signal, which anneals to complementary nucleotide sequences on the first oligonucleotide to provide, in a preferred embodiment, a 3′ overhang of the first tag oligonucleotide and wherein the 5′ end of the second tag oligonucleotide is phosphorylated.
[0088] The complementary oligonucleotide to the tag oligonucleotide is referred to herein as α-tag or the α-tag oligonucleotide.
[0089] The present invention provides, therefore, in one embodiment:—
(i) a solid phase such as a microsphere, microchip or the sides of a well in a microliter plate; and (ii) a tag oligonucleotide having a chemical moiety conjugated to the oligonucleotide via a molecule of mc+n atoms as described above;
wherein the chemical moiety on the oligonucleotide is in covalent bond formation with a chemical moiety on the surface of the solid phase.
[0092] Again, as stated above, although a covalent linkage such as an amide bond or thioether bond is particularly useful in the practice of the present invention, it is but one of a whole myriad of covalent linkages which may be used in accordance with the present invention.
[0093] In general, the efficient production of a solid phase, especially on a surface with great stability, is difficult. In many systems, great care is required to ensure maximally efficient chemical reactions. Enzymatic manipulations, on the other hand, are relatively easy and can be performed in aqueous solutions, at moderate temperatures. The main advantage of the system described here is flexibility. Since the difficult covalent linkage between tag and solid phase is only performed once in a large stock, subsequent additions to the initial tag DNA is done easily at any point in the future with virtually any desired target DNA on whatever portion of the original stock required by a particular application.
[0094] The above solid support generally further comprises a second oligonucleotide (α-tag) in complementary base pairing to the first mentioned oligonucleotide (tag) such that there is optionally a label on the 3′ end of the α-tag oligonucleotide and the 5′ end is phosphorylated wherein the tag oligonucleotide overhangs the α-tag oligonucleotide at the 3′ end of the tag oligonucleotide.
[0095] The next step is the generation of a bridge oligonucleotide which enables anchoring of a target nucleic acid molecule to the tag oligonucleotide anchored to the solid phase.
[0096] The bridging oligonucleotide, in the case where the tag oligonucleotide overhangs at its 3′ end relative to the annealed αtag oligonucleotide, anneals in a direction where the bridge's 3″ end is reverse complementary to the overhanging portion of the tag oligonucleotide The bridge's 5′ end is thus a 5′ overhang of the tag: bridge double stranded (ds) DNA.
[0097] The 5′ end of the bridge is then reverse complementary to the 5′ end portion of a target nucleic acid molecule. Both the 5′ end of the target nucleic acid molecule and the 5′ end of the labeled α-tag oligonucleotide (complementary to the anchored tag oligonucleotide) are phosphorylated. A ligase-mediated covalent attachment then forms anchoring the target nucleic acid molecule to the anchored tag via the bridging oligonucleotide.
[0098] Accordingly, in one embodiment, there is provided a substrate for anchoring a target nucleic acid molecule, said substrate comprising:—
(i) a solid phase having a first chemical moiety on its surface; (ii) a tag oligonucleotide comprising a second chemical moiety in covalent bond formation with the first chemical moiety, said second chemical moiety conjugated to the tag oligonucleotide via a molecule of structure mc+n atoms as defined above; (iii) an optionally labeled oligonucleotide reverse complementary to the tag oligonucleotide; and (iv) a bridging oligonucleotide having complementary based to the 3′ overhang region of the tag oligonucleotide and complementary bases to the 5′ end portion of the target nucleic acid molecule wherein the target nucleic acid molecule is anchored to the tag oligonucleotide via ligase-mediated conjugation.
[0103] The bridging oligonucleotide may be part of the solid phase complex prior to anchoring of the target nucleic acid molecule or it may be first added to and annealed to the target nucleic acid molecule prior to annealing to the tag oligonucleotide.
[0104] Yet in a further embodiment, the solid phase-tag oligonucleotide complex, the bridging oligonucleotide and the target nucleic acid molecule are mixed together and subjected to ligation conditions.
[0105] The target nucleic acid molecule is specific for each conjugation experiment. Generally, its initial 5-30 bases are complementary to the bases at the 5′ end of the bridging oligonucleotide. The 5′ end of the target nucleic acid molecule is generally phosphorylated. A minimum of five bases complementary between the target nucleic acid molecule and the tag oligonucleotide is enough to enable ligation but generally insufficient to permit cross-hybridization, especially when multiplexing a large number of target molecules.
[0106] Yet another aspect of the present invention provides a universal nucleic acid anchoring system comprising the structure:—
[0000] S(-T) p
[0000] wherein:
S is a solid support having a chemical moiety capable of covalent bond formation with a second chemical moiety; T is a partially double-stranded oligonucleotide comprising single-stranded tag oligonucleotide having said second chemical moiety linked via a spacer molecule to its 5′ end, said spacer comprising carbon atoms having the structure mc+n wherein in is the number of repeats of length c, and n is the number of atoms in the spacer molecule not included in the repeats and wherein mc+n generally ranges from about 1 to about 100 n ; said tag oligonucleotide further comprising a complementary oligonucleotide (α-tag) annealed to the tag oligonucleotide to provide a method of measurement of conjugation success a; said T further comprising a bridging oligonucleotide having a nucleotide sequence reverse complementary to the 3′ overhang nucleotide sequence of the tag oligonucleotide and a further nucleotide sequence complementary to a nucleotide sequence on the 5′ end of a target nucleic acid molecule; wherein T may be represented p times on the solid support wherein p is from about 1 to about 100,000.
[0110] Still another aspect of the present invention contemplates a method for immobilizing a target nucleic acid molecule to a partially double-stranded tag oligonucleotide anchored to a solid support, said method comprising ligating a phosphorylated 5′ end of the target nucleic acid molecule to a complementary single-stranded portion of the tag oligonucleotide under conditions to permit ligase-mediated covalent bond formation wherein said tag oligonucleotide is covalently anchored to the solid support via covalent bond formation between a first chemical moiety on the surface of the solid support and a chemical moiety conjugated to the tag oligonucleotide via a molecule of structure mc+n as defined above and wherein the tag oligonucleotide is rendered partially double-stranded by annealing a complementary oligonucleotide to the tag oligonucleotide leaving a single-stranded 3′ terminal portion of the tag oligonucleotide which is used to capture the target nucleic acid molecule via a bridging oligonucleotide.
[0111] The present invention further provides a kit useful in capturing and/or anchoring target nucleic acid molecules. The kit is conveniently in multi-compartment form wherein a first compartment comprises a solid support such as microspheres or microchips having a surface chemical moiety. A second compartment comprises a tag oligonucleotide having a chemical moiety capable of covalent bond formation with the surface chemical moiety of the solid support and wherein the chemical moiety on the tag is linked to the tag via a molecule of the mc+n structure as defined above. A third compartment comprises a labeled complementary tag oligonucleotide and a fourth compartment comprises a bridging oligonucleotide.
[0112] In an alternative, the kit may comprise a solid support having a partially double-stranded tag oligonucleotide anchored thereto comprising a single-stranded 3′ end portion. The kit may then have a bridging oligonucleotide already attached to the single-stranded portion of the tag oligonucleotide or this may be maintained separately. A target nucleic acid molecule is then ligated to the tag oligonucleotide via the bridge oligonucleotide.
[0113] The anchoring system of the present invention has many uses such as in deconvolution of complex mixtures of nucleic acid molecules, sorting of nucleic acid molecules and for generation of microarrays, suspension arrays and optical fiber arrays.
[0114] The system may also be adopted to facilitating in vitro transcription and/or translation and the transcription and/or translation products assayed or used to screen for ligand or binding partners.
[0115] The anchoring system of the present invention may be fully or partially automated and may be used for high throughput screening of target nucleic acid molecules.
[0116] The present invention is further described by the following non-limiting Examples.
Example 1
Selection of Components of Anchoring Systems
1. Solid Support
[0117] The physicochemical structure of the surface of the solid support is an important consideration for the choice of chemical reactive moiety of the DNA to exploit for covalent attachment. The main attributes of the surface are:—
[0000] (a) ease of manipulation;
(b) inexpensive;
(c) stable in extremes of temperatures; and
(d) stable in both aqueous and organic solvents.
[0118] Suitable surfaces include glass slides for solid microarrays and silica and methacrylate microspheres for use in suspension arrays, optical fiber arrays, or micromachined devices. The one favoured at the moment and representing the most common conjugation chemistry involves a thiolated surface is exemplified below.
2. A Universal Tag for Initial Modification of the Surface
[0119] In the present system, a reactive end (amine, thiol or acryl group) is used at the 5′ end of the DNA oligonucleotide. In the example given here, the 5′ reactive group is an acryl, followed by two —(OCH 2 CH 2 ) 6 spacers. These additions are made at point of synthesis.
[0120] To this common 5′ end architecture is added a 20 base linker designed on the T7, T3, or SP6 RNA polymerase promoters along with an additional 18 bases comprising transcription and translation start signals.
[0121] The universal tag comprises the structure:—
[0000]
[SEQ ID NO: 1]
5′-Acrydite-C18-C18-TAATACGACTCACTATAGGGCGA
3. A Labeled αα-Tag
[0122] To assay the successful covalent attachment of the tag to the surface, a labeled reverse complementary 16-mer built to bind to the first 16 bases of the tag is used. The 3′ end is fluoresceinated with 6-FAM and the 5′ end is phosphorylated.
[0123] The sequence of the complementary tag is as follows:—
[0000]
5′PO4-ATAGTGAGTCGTATTA-FAM
[SEQ ID NO: 2]
4. A Bridge Oligo
[0124] This bridge is built to be complementary to the last six bases of the tag as well as the first five bases of the target. It is kept small for easy removal from reactions, but long enough to be easily scored by electrophoresis. The bridge needs no 5′ modifications.
[0125] Its structure is:—
[0000]
5′-TCCCGCTCCTAGA
[SEQ ID NO: 3]
5. Phosphorylated Target
[0126] This DNA is made to be specific for each experiment. It has its initial five bases reverse complementary to the five 5′ bases of the bridge. The 5′ end of the target is phosphorylated. The five bases of the target which hybridise to the 5′ end of the bridge are sufficient to enable ligation, but not sufficient enough to significantly add to cross-hybridization. In the present system test, the 3′ end of the target contained the reverse complement of the SP6 RNA polymerase promoter allowing for either translation or, in concert with 11 promoter, PCR amplification.
[0127] An example of a target is as follows:
[0000]
[SEQ ID NO: 4]
5′-PO4-GGATCTGACACGGACTGATGAATTCC-α-sp6-3′
Example 2
System Set-Up
1. Tag is Conjugated to Surface
[0128] The execution of this step depends on the chemistry and surface used. The assay for measurement of amount of covalent binding is performed by binding α-tag to the solid surface. Amount of fluorescence at 521 nm is measured after excitation by a high-energy light source. The argon ion laser of the ABI 377, ABI 3700 or BD FacsCalibur may conveniently be used to measure this quantity.
2. Target is Ligated to Tag by Bridging Ligation
[0129] The bridge and target are added in equimolar amounts to the tag-modified surface with T4 DNA ligase. Successful ligation of target to tag is measured indirectly by measuring the ligation of α-tag to bridge electrophoretically (a 27-mer vs an 11-mer and a 16-mer) or by measuring the binding of OLIGREEN, a single stranded fluorescent binding dye from Molecular Probes. By measuring the amount of binding to the surface before and after ligation, it is easy to quantify the amount of ssDNA gained by the ligation-anchoring step.
Example 3
Universal Primed Target Production
[0130] The primary aim of this Example is to introduce a high efficiency, low cost, easily used microsphere based system for capturing nucleic acid molecules. The present system is useful for specific testing of reagents which can be used in conjunction with a flow cytometer or other bead based instrument.
[0131] The system may also be used for generation of capture reagents for combinatorial screening as well as a system for solid phase PCR and/or single-stranded extensions.
[0132] The three component linker used to modify a thiolated solid phase is shown in FIG. 1 .
[0133] A Universal Forward Oligo (UF) is then generated and in one example comprises the SP6 RNA polymerase promoter with a 5′ acrydite, a 30-atom spacer, followed by the sequence. This is conjugated to form a bead: UF complex ( FIG. 2 ).
[0134] The efficiency of conjugation is measured by measuring the binding of α-UFO which is a phosphorylated, internally labeled complement to the first 13 bases of the UFO.
[0135] The resulting bead has a configuration shown in FIG. 3 .
[0136] Successfully conjugated bead preps are made in bulk, 5×10 10 beads (usually 5×10 6 beads/ul, so 5×10 9 beads/ml=about 10 ml of bead stock).
[0137] Specific targets are produced by a two step ligation protocol in which a Universal Bridging Oligo (UBO) is first bound to the 5′ end of each target and then the resulting “sticky-ended” target is ligated to the bead: UFO:α-UFO defined as above.
[0138] The UBO has the following characteristics. The first six bases 5′ will be complementary to the last six bases of the UFO and the final five bases will be random. The resulting complex is shown in FIG. 4 .
[0139] Thus, a small (e.g. 1024) library is created. The key to this system working is the randomness of this library as well as the workable size. The size of this variable domain is kept at five to be both manageable as well as easily removed by gel filtration at the end of the first hybridization step.
[0140] The target DNA is synthesized with a 5′ phosphate, a number of bases specific to the experiment, and a terminal 17 bases complementary to the T3 RNA polymerase promoter. As an example, a target of sequence GCAACCATTATC [SEQ ID NO:5] is synthesized with a 5′ PO 4 and a terminal T3 polymerase signal sequence of TCCCTTTAGTGAGGGTT [SEQ ID NO:6] for the following final construct:
[0000]
[0141] To assess the efficiency of the ligation, the relative amounts of bound 13-mer and 24-mer would be ascertained by quantitative capillary electrophoresis on an ABI 3700 analyzed with Genescan software. Populations of particles from successful ligations would be sorted by flow cytometry.
Example 4
Ligase-Mediated Customization
[0142] Phosphorylated target DNA and bridge DNA is mixed with tagged microspheres, T4 DNA ligase, and ATP. After brief reaction at room temperature, bridge and unincorporated targets are removed by heat and separation from the microspheres. A diagram of ligase-mediated customization is shown in FIG. 4 .
Example 5
Ligation-Mediated Customization Efficiency
[0143] Customized beads (tag+target; M1 or left-most peak of FIG. 5 ) and tagged beads (Tag only/no target; M2 or right-most peak) were stained with a small amount of OLIGREEN (registered trademark). Beads were run on Becton Dickinson FacsCalibur flow cytometer. Ligation efficiency is measured by testing the ratio of M2 (tagged+target)/M1 (tag only). For this Example, M2/M1 is approximately 2.5, indicative of a successful ligation. M2/M1 values of <1.7 generally represent ligation efficiency of less than 80% of target DNA modified. The results are shown in FIG. 5 .
Example 6
Test of Optimal Overhang Length for Ligase-Mediated Conjugation to Tagged Microspheres
[0144] Bridge oligonucleotides differing by only the number of 5′ bases in direct base pairing with target were tested by OLIGREEN (registered trademark) ligation assay (see FIG. 6 ). In this Figure, M1 or Marker 1 is the mean fluorescence of the tagged microsphere. M2 is the mean fluorescence of the tagged microsphere post-ligation of target. The quantity M2/M1 measures the relative gain in fluorescence and thus the amount of bound DNA. In this Example, five and six base overlaps have greater ligation efficiency than four base overlap. The results are shown in FIG. 6 .
Example 7
Universal Binding Analogs for General Use Bridges in Ligation-Mediated Conjugation of Tagged Microspheres
[0145] All bridges had a common sequence of 5′- CXXXXXT [SEQ ID NO:8] CAT AGC TGT CCT-3′ [SEQ ID NO:9]. The 3′ italicized 12 bases were common to all bridges and hybridized to the 3′ 12 bases of the immobilized tag. The underlined sequence CXXXXXT [SEQ ID NO:8} represents the variable 5′ overhang which hybridized to the target sequence. The Xs represent nucleotide positions which were variable in this test between the actual base and inosines, which are general binding base analogs. FIG. 7A represents the substituted bridge. FIGS. 7B-E represent increasing numbers of inosines in the bridges. A box in the left side of each figure gives the tested sequence of the 5′ overhang. In each experiment, 1×10 5 beads with immobilized tags were reacted with 2.0 nMols of target oligonucleotide and appropriate bridge as well as 20 units T4 DNA ligase, 1 mM ATP, 10 mM MgCl 2 . Reactions were carried out at room temperature for 15 minutes. Unligated DNAs were removed by two 0.2 M NaOH washes. Beads with ligase mediated conjugated products were assayed by OLIGREEN (registered trademark) binding assay using Becton Dickinson FacsCalibur. Ligation efficiency is calculated as the sample fluorescence post binding (M2) divided by the control mean fluorescence (M1). At least 200 events for each data point were collected. The results are shown in FIG. 7 .
Example 8
Use of Ligase-Mediated Customized Silica Microspheres in Solid Phase PCR
[0146] This Experiment is divided into three sections. (A) A 187 by DNA fragment generated by PCR with the following landmarks. (B) A tagged microsphere is customized with the phosphorylated forward primer. The FAM labeled α-tag probe as well as the Cy5 complement to the target are used to assess the efficiency of the conjugation. Background levels of binding are determined for all labeled probes. (C) PCR is performed using immobilized forward primer. Success is determined by stripping non-covalently bound strand and reprobing with either the original reverse primer or the internally labeled complement. The results are shown in FIG. 8 .
[0147] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications. The invention also includes all of the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of any two or more of said steps or features.
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The anchoring system generally comprises a solid support and a chemical linking moiety useful for ether formation with another chemical moiety on a nucleic acid molecule. The present invention further contemplates methods for anchoring a nucleic acid molecule to a solid support via a covalent linkage. The anchoring system of the present invention is useful inter alia in construction of nucleic acid arrays, to purify nucleic acid molecules and to anchor nucleic acid molecules so that they can be used as templates for in vitro transcription and/or translation experiments and to participate in amplification reactions. The present invention is particularly adaptable for use with microspheres and the preparation of microsphere suspension arrays and optical fiber arrays. The anchoring system permits the generation of an anchored oligonucleotide for use as a universal nucleic acid conjugation substrate for any nucleic acid molecule or population of nucleic acid molecules. The present invention further provides a kit useful for anchoring nucleic acid molecules or comprising nucleic acid molecules already anchored to a solid support.
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FIELD OF INVENTION
[0001] The present invention relates in general to the field of subsea equipment.
BACKGROUND ART
[0002] The present invention relates to methods and systems for subsea energy extraction. In particular, the present invention relates to a hydraulic signature tester for assessment and monitoring of pressure systems.
[0003] Various mechanisms have been employed to prevent failure of subsea components due in part to maintenance being performed normally on a time related basis rather than a condition based scenario. This not only adds needless costs, it also opens the system up for infant mortality of critical equipment due to needless repairs.
[0004] Thus there exists a need for an apparatus that is capable of dynamically measuring fluid flow anomalies via pressure and time constraints during normal maintenance checks to fully analyze the condition of the equipment to determine if a repair is required. After repairs, the system of a preferred embodiment of the invention is used not only to confirm the quality of the repair, but also provide a new birth certificate for the repaired equipment to be used as a base line for future tests. In the case of new equipment, analysis with this system would be the initial birth certificate.
SUMMARY OF THE INVENTION
[0005] The present invention provides a subsea apparatus for monitoring and testing of a hydraulic signature having a fluid supply, a first pressure line coupled to the fluid supply, a second pressure line coupled to the fluid supply; and a pressure recording device operatively coupled to both the first pressure line and the second pressure line. Storage of pre-determined pressure data is representative of the aforementioned pressure lines. The first pressure line can function at a lower pressure than the second pressure line. A pressure recording device records data to allow comparison of actual pressure data on said lines with said stored data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Further benefits and advantages of the present invention will become more apparent from the following description of various embodiments that are given by way of example with reference to the accompanying drawings:
[0007] FIG. 1 represents a schematic view of a hydraulic signature tester according to a preferred embodiment of the invention.
DESCRIPTION OF THE INVENTION
[0008] While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention and do not delimit the scope of the invention.
[0009] To facilitate the understanding of this invention, a number of terms are defined below. Terms defined herein have meanings as commonly understood by a person of ordinary skill in the areas relevant to the present invention. Terms such as “a”, “an” and “the” are not intended to refer to only a singular entity, but include the general class of which a specific example may be used for illustration. The terminology herein is used to describe specific embodiments of the invention, but their usage does not delimit the invention, except as outlined in the claims.
[0010] Referring now to the figure, FIG. 1 illustrates a schematic view of an apparatus for testing a hydraulic signature 10 . Apparatus for testing a hydraulic signature 10 includes fluid supply 12 , first pressure line 14 , second pressure line 16 , and pressure recording device 18 . Pressure recording device 18 couples to first pressure line 14 and second pressure line 16 . First pressure line 14 functions at a lower pressure than second pressure line 16 . Pressure recording device 18 records data to allow interpretation of both real time and theoretical pressure rates. As pressurized fluid is conveyed from a source such as fluid supply 12 , after passing through optional valves, it is dispensed into first pressure line 14 and second pressure line 16 . First pressure line 14 is intended to withstand lower pressures. Second pressure line 16 is intended to withstand higher pressures.
[0011] First pressure line 14 ultimately conveys lower pressure readings into pressure recording device 18 . Second pressure line 16 also ultimately conveys a pressure reading into pressure recording device 18 . Pressure recording device 18 receives pressure inputs from first pressure line 14 and second pressure line 16 and compares pressure values received to theoretical pressure values developed through lab testing in various conditions, or through calculation. As pressure recording device 18 monitors real time pressures, it compares them to numerous inputs. Pressure recording device 18 can also monitor real time pressures when coupled to other systems, such as a blow out “BOP” preventer. After pressure recording device 18 has received pressure values, pressure may be relieved from first pressure line 14 and second pressure line 16 . First pressure line 14 may release pressure via relief valve 24 . Second pressure line 16 may release pressure via relief valve 26 . A first pressure gauge 20 operatively couples to first pressure line 14 to provide real time pressure, second pressure gauge 22 operatively couples to second pressure line 16 to provide real time pressure.
[0012] In certain embodiments pressure gauge 20 may operatively associate with first pressure line 14 . Additionally, pressure gauge 22 may operatively associate with second pressure line 16 . First pressure line 14 may also include a relief mechanism 24 for releasing pressure from first pressure line 14 . Second pressure line 16 may also include a relief mechanism 26 for releasing pressure from second pressure line 16 .
[0013] Regulating mechanism 28 may be operatively disposed between fluid supply 12 and first pressure line 14 . Similarly, regulating mechanism 28 may be operatively disposed between fluid supply 12 and second pressure line 16 . Transducer 30 , or similar communicating device, may operatively couple to first pressure line 14 , second pressure line 16 , or both lines to transmit pressure readings to an offsite source.
[0014] First pressure line 14 may optionally include gauge saving valve 32 in order to control fluid flow. Additionally isolation valve 34 may be included to fully prevent fluid flow from reaching pressure recording device 18 in certain instances. Such instances arise when greater pressures are being transmitted to pressure recording device 18 via second pressure line 16 . In certain embodiments, an apparatus may be coupled to fluid supply 12 that maintains a constant fluid flow regardless of pressure and temperature variations.
[0015] Additionally, numerous hydraulic valves may be installed about various portions of apparatus for testing a hydraulic signature 10 . For example, hydraulic valve 38 may be oriented to prevent pressure from over accumulating in first pressure line 14 and second pressure line 16 . Disposing hydraulic valve 38 in a position that allows pressure to enter first pressure line 14 and second pressure line 16 without overly accumulating, and allows for apparatus for testing a hydraulic signature 10 to be oriented in a steady state condition so that fluid entering from fluid supply 12 is constant throughout the system. In the event of an emergency, fluid contained within apparatus for testing a hydraulic signature 10 may be immediately released by opening hydraulic valve 30 .
[0016] Similarly, valve 38 may be disposed prior in sequence for first pressure line 14 and second pressure line 16 to prevent fluid from entering first pressure line 14 and second pressure line 16 . In the event that bursts of high pressure or low pressure fluids are required to be implemented towards pressure recording device 18 , pressure may build after entering through fluid supply 12 and be subsequently released through valve 38 . An initial pressure gauge 39 may be disposed prior to regulating mechanism 28 in order to measure fluid pressure emanating from fluid supply 12 . Pressure gauge 40 may be disposed prior to entering valve 38 in order to measure pressure within the fluid line, to measure pressure exerted on hydraulic valve 38 , to determine pressure drop over first pressure line 14 and 15 , second pressure line 16 , and to compare real time pressure exertion of other pressure gauges. Additionally, a pressure reducing mechanism 41 may be disposed between regulating mechanism 28 and hydraulic valve 38 .
[0017] In operation, fluid may accumulate within one or more fluid lines while leaving hydraulic valve 38 closed. After sufficient fluid has accumulated within one or more fluid lines and pressure has reached steady state, a reading may be taken from pressure gauge 40 . After a reading has been taken and assuming hydraulic valve 30 is in a closed position, valve 38 may be opened in order to allow fluid to reach first pressure line 14 and second pressure line 16 . As pressure is released into first pressure line 14 and second pressure line 16 , and assuming relief valve 24 and relief valve 26 are in closed positions, pressure recording device 18 may take real time pressure values. At the same time, pressure values are being recorded, in readings taken from first pressure gauge 20 , second pressure gauge 22 , and readings taken pressure gauge 40 , may all be compared to ensure that first pressure line 14 and second pressure line 16 are maintaining pressure. It is plausible that a small drop may be noted, but the drop should be minimal. Once pressure recording device 18 has performed its function, pressurized fluid held within first pressure line 14 and second pressure line 16 may be released via relief valve 24 and relief valve 26 .
[0018] Regulating mechanism 28 may be implemented ahead of pressure gauge 40 in order to control the amount of fluid entering apparatus for testing a hydraulic signature 10 . Regulating mechanism 28 may be implemented in order to establish a laminar or steady state fluid flow entering apparatus 10 . Similarly regulating mechanism 28 may be implemented to control fluid input into apparatus for testing hydraulic signature 10 .
[0019] In certain embodiments, pressure recording device 18 can be used to illustrate flow rate and pressure trends. For example, apparatus for testing hydraulic signature 10 can be initially employed to receive initial pressure values. Pressure values which are transmitted through apparatus for testing a hydraulic signature 10 may be initially recorded over a given time interval. Assuming that all components of apparatus for testing a hydraulic signature 10 are properly functioning and that an associated apparatus that it couples with is properly in line, apparatus for testing hydraulic signature 10 can be used to record pressure values. Apparatus for testing a hydraulic signature 10 can be used to record both steady state pressures and dynamic pressure rates over time periods.
[0020] For example, if one desires to confirm that pressure is being maintained within the system or an associated apparatus, pressure may be ramped up to a desired pressure value in which hydraulic valve 30 , relief valve 24 , and relief valve 26 are closed. During this time period dual pressure recorder 18 may record such pressure values over a period of time. As pressure is increased within apparatus for testing a hydraulic signature 10 the increasing pressures may be recorded. Once a desired pressure is attained, pressure may cease being input and hydraulic valve 38 may be closed. For a specified period of time, pressure values should continue to be recorded via pressure recording device 18 . Pressure should be maintained in the system for a period of time so that one can determine if all components are properly functioning. These components can include various seals, sealing mechanisms, and transmission mechanisms. Pressure recording device 18 may then transmit data to another location such as an onboard computer or a processor, or offsite data center. In alternative embodiments, pressure recording device 18 may transmit data to an integrated onboard processor which in turn sends data wirelessly or through data lines to another processor or data storage device. Assuming that all components are properly functioning, these values may be recorded as “good” values. Once “good” values have been attained, such tests can be repeated to ensure that apparatus for testing a hydraulic signature 10 and associated components are properly functioning. As various tests are performed using apparatus for testing a hydraulic signature 10 , received pressure values can be recorded and compared to the initially obtained “good” values. In the event that subsequent pressure values do not result in substantially similar values to “good” values previously achieved, one may be alerted that an associated component may be near failure. An example, which is illustrative of such behavior, occurs when hydraulic valves are not fully sealing, perhaps due to additives jammed in their path. Another example which can allow for pressure lossage is pipe joints which can wear down due to excessive coupling or over torque.
[0021] Additionally, apparatus for testing hydraulic signature 10 can dynamically compare hydraulic signatures. Hydraulic valve 30 may be opened to release pressure which will eventually reach an associated component. Pressure can reach an associated component most often via hydraulic valve 30 , vent 24 , vent 26 , or any additional pressure releasing mechanism associated with apparatus for testing hydraulic signature 10 . As pressure is disposed within apparatus for testing hydraulic signature 10 and measurements are taken over time, via pressure recording device 18 a hydraulic signature can be obtained. Assuming that all components are properly functioning, this hydraulic signature may be deemed a “good” hydraulic signature, without having to close any valves. Apparatus for testing hydraulic signature may continue to function over time while data is gathered via pressure recording device 18 . As pressure is gathered over a period of time and various flow rates are implemented according to the desired task, each subsequent flow rate can be compared to the initially achieved “good” hydraulic signature and various trends can be observed. In the event that sufficient wear and tear has occurred on various components of apparatus for testing hydraulic signature 10 or an associated component, and the hydraulic signature begins to shift, the associated component or valves contained within and/or associated with apparatus for testing hydraulic signature 10 can be closed ahead of time in order to prevent failure.
[0022] In certain embodiments, predetermined hydraulic signatures can be loaded onto pressure recording device 18 . Once apparatus for testing hydraulic signature 10 begins functioning, existing flows and pressures can be compared to predetermined values and functionality of both apparatus for testing hydraulic signature 10 and/or associated components can be determined. In the event that flows and pressures are not attaining predetermined hydraulic signature levels, pressure and flow can be increased or decreased as necessary. For example, lower flow rate data can be preloaded onto pressure recording device 18 prior to starting apparatus for testing hydraulic signature 10 . Once apparatus for testing hydraulic signature 10 begins functioning any components that are improperly functioning would not ordinarily be picked up, but rather would be used to determine the initial hydraulic signature. Pre-stored data is beneficial because if a component of apparatus for testing hydraulic signature is not properly functioning at the onset, the failure can be immediately detected, the component repaired, and the machines functionality restored.
[0023] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification, but only by the claims.
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The present invention provides a subsea apparatus for testing a hydraulic signature which has a fluid supply, a first pressure line coupled to the fluid supply, a second pressure line coupled to the fluid supply; and a pressure recording device operatively coupled to both the first pressure line and the second pressure line. A pressure recording device is capable of storing pre-determined pressure data representative of said pressure lines. The first pressure line functions at a lower pressure than the second pressure line while a pressure recording device records data to allow comparison of actual pressure data on the first and second pressure lines with said stored data.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/941,979, filed Jun. 5, 2007, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention generally relates to construction methods, equipment, and systems used during the construction of a building. More particularly, this invention relates to a cable management assembly and method by which cables used to hoist and secure a temporary elevator car are prevented from becoming entangled as the elevator car is raised and lowered within an elevator hatchway during construction of a multistory building.
[0003] During the installation of components of an elevator system in a building under construction, a temporary elevator car is often installed to deliver the elevator components and support the elevator constructors within the hatchway (hoistway). One such approach is represented in FIG. 1 , which schematically represents a hatchway 10 within a multistory building 12 under construction. A jump deck 14 is placed over the elevator hatchway 10 at an upper floor 16 of the building 12 , and a temporary elevator car 18 (or “car sling”) is suspended with a hoist cable 24 beneath the jump deck 14 . The elevator car 18 is depicted in FIG. 1 as comprising a working deck 19 A on which the elevator constructors stand during installation of the elevator components, and a secondary deck 19 B on which supplies can be stored. The secondary deck 19 B is attached to the working deck 19 A with stiles 23 . The working deck 19 A may be supported by the crosshead (not shown) of the permanent elevator car that will later be installed in the hatchway 10 , and the secondary deck 19 B is shown supported by a safety plank 21 on which the permanent elevator car will be supported. Safeties (not shown) on the safety plank 21 are operated by a safety cable 34 routed from a governor 35 on the jump deck 14 to the safety plank 21 through a governor tension sheave 38 mounted by a bracket 36 within the pit 32 at the bottom of the hatchway 10 . The car 18 travels up and down within the hatchway 10 on a temporary hoist cable 24 (typically a wire rope) by means of a hoist motor 20 on the working deck 19 A, and is equipped with shoes (not shown) or similar components that engage the installed guide rails 22 . The hoist cable 24 is attached to the deck 19 A, passes over a sheave 28 suspended beneath the jump deck 14 to a hoist motor 20 on the working deck 19 A, and then passes down through the hatchway 10 and through or around the car 18 , from which the loose or “dead” end 30 of the hoist cable 24 hangs freely downward toward the pit 32 . As the car 18 travels upward through the hatchway 10 under the action of the hoist motor 20 , the loose end 30 of the hoist cable 24 runs downward toward and eventually into the pit 32 . When installation of the elevator system components has been completed up to the jump deck 14 , the jump deck 14 is raised (jumped) to a higher floor (not shown) of the building 12 . Because the car 18 is raised along with the jump deck 14 , the car 18 must be lowered from the deck 14 with the hoist cable 24 to resume installation of elevator components at the prior location of the deck 14 in the hatchway 10 .
[0004] There are various problems and hazards associated with the building and use of temporary elevator cars of the type represented in FIG. 1 . One problem is that, as the elevator system is installed and the temporary car 18 is raised to higher levels, the loose end 30 of the hoist cable 24 can be difficult to control. When the loose end 30 of the cable 24 feeds into the pit 32 as the elevator car 18 runs up through the hatchway 10 , the loose end 30 of the cable 24 can become tangled with equipment in the pit 32 and suspended in the hatchway 10 , such as a temporary power supply cable 26 that supplies power to the car 18 during construction. When this happens, the elevator constructors must stop work and free the tangled cable 24 . This task is not only a nuisance that delays the construction process, but can also be hazardous for the constructors.
[0005] Another issue is that, when the jump deck 14 is raised within the hatchway 10 , the bracket 36 of the safety cable 34 must be physically detached from a rail 22 within the pit 32 by a constructor, the cable 34 , bracket 36 , and tension sheave 38 must be raised up through the hatchway 10 , and then the bracket 38 reattached to the guide rail 22 at a higher level within the hatchway 10 . This operation is hazardous, in that it entails raising a significant amount of weight due to the weight of the cable 34 , bracket 36 , and sheave 38 . In addition, this operation is typically performed by a constructor who must typically stand on a beam (not shown) spanning the hatchway 10 .
[0006] In view of the above, it would be desirable if an improved method were available for by which the temporary cables used during construction of an elevator system could be handled and managed to avoid the above-noted issues.
BRIEF SUMMARY OF THE INVENTION
[0007] The present invention provides a cable management assembly and method by which cables used to hoist and secure a temporary elevator car are prevented from becoming tangled as the elevator car is raised and lowered within an elevator hatchway during construction of a multistory building.
[0008] According to a first aspect of the invention, the cable management assembly is adapted for installation below an elevator car within an elevator hatchway of a building. The cable management assembly includes first, second, and third members. The first member has a longitudinal extent and oppositely-disposed longitudinal ends, and the second and third members are connected to the first member at the longitudinal ends thereof. At least one of the second and third members is longitudinally extendable relative to the first member for adjusting a length of the cable management assembly defined by the first, second, and third members. The first, second, and third members define an upper side of the cable management assembly adapted to face upward when the cable management assembly is installed in the hatchway. The cable management assembly further includes a mechanism associated with each of the second and third members for movably engaging vertical elevator guide rails within the hatchway so as to enable the cable management assembly to vertically traverse the hatchway. The cable management assembly also includes a mechanism for movably and reversibly routing a hoist cable toward the upper side of the cable management assembly, along a portion of the cable management assembly, and away from the upper side of the cable management assembly.
[0009] According to a second aspect of the invention, a method is provided for raising and lowering the elevator car within the hatchway with a cable management assembly, preferably in accordance with claim 1 . The cable management assembly is preferably installed below the elevator car within the hatchway. The movable engaging mechanism movably engages the guide rails within the hatchway to enable the cable management assembly to vertically traverse the hatchway, and the hoist cable is routed through the routing means so as to have first and second portions engaging the routing means at two longitudinally spaced locations of the cable management assembly. Also in the preferred embodiment, the elevator car is suspended by the hoist cable from a fixed platform, the first portion of the hoist cable is coupled to a hoist on the elevator car, the second portion of the hoist cable is coupled to the car through a spool, and the elevator car and cable management assembly can both be raised by hoisting the hoist cable with the hoist.
[0010] Significant advantages of this invention include the elimination of a loose end of the hoist cable hanging into the pit of the elevator hatchway by routing the hoist cable through the cable management assembly in a manner that allows an elevator constructor to freely raise and lower the car and hoist cable in a safe manner. The cable management assembly can also be adapted to mount a tension sheave for a safety cable associated with the elevator car, so that the safety cable can also be raised and lowered with the car in a safe manner.
[0011] Other objects and advantages of this invention will be better appreciated from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 represents a hatchway within a building under construction, in which equipment is present for installing components of an elevator system within the hatchway in accordance with the prior art.
[0013] FIG. 2 represents a view of a hatchway similar to FIG. 1 , but further utilizing a cable management assembly in accordance with a preferred embodiment of the invention.
[0014] FIGS. 3 and 4 are side and top views, respectively, of the cable management assembly of FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
[0015] FIGS. 3 and 4 represent a cable management assembly 40 according to a preferred embodiment of the invention, and FIG. 2 depicts the cable management assembly 40 installed for use in a hatchway 10 of a multistory building 12 . The invention finds particular use in buildings under construction, similar to the scenario described for FIG. 1 . As such, FIG. 2 uses consistent reference numbers to identify the same or functionally similar structures to those identified in FIG. 1 . It should be further noted that the drawings are drawn for purposes of clarity when viewed in combination with the following description, and therefore are not to scale.
[0016] The assembly 40 preferably comprises three basic components: a middle section 42 and two end sections 44 at longitudinally-opposed ends of the middle section 42 . Structural steel grades, for example, carbon steels such as ASTM A36 and ASTM A500, are suitable materials for the structural components of the assembly 40 , though the use of other materials is foreseeable. The middle and end sections 42 and 44 are shown as having square tubular cross-sections, though it is foreseeable that various structural elements with different cross-sections could be used to construct the assembly 40 . Each end section 44 is generally T-shaped, with a leg section 48 and an arm section 50 that may be constructed by welding two tubes as evident from FIGS. 3 and 4 . The leg section 48 of each end section 44 is sized to telescope with one of the opposite ends of the middle section 42 and be secured therewith using bolts 46 or another suitable fastener. As represented in FIGS. 3 and 4 , the leg sections 48 have smaller cross-sections than the middle section 42 to provide the desired telescoping arrangement, though it is foreseeable that the middle section 42 could telescope into the end sections 44 . In the embodiment shown, suitable cross-sectional dimensions for the middle section 42 and end members 44 are about 4.0 inches (about 10 cm) and about 3.5 inches (about 9 cm), respectively, though these dimensions can vary. The end sections 44 are adapted to be extendable relative to the middle section 42 to enable the length of the cable management assembly 40 to be expanded to fit essentially any elevator rail dimension, for example, up to about eight feet (about 2.5 meters) or so, with lesser and greater expanses also being foreseeable.
[0017] A guide tube 52 is welded or otherwise attached to the outer extremity of each arm section 50 , and a guide plate 54 is bolted or otherwise attached to each guide tube 52 . Each guide plate 54 is shown as carrying cam followers 56 A and 56 B for rotational engagement with one of the guide rails 22 within the hatchway 10 as represented in FIG. 2 . Two followers 56 A are oriented for engaging opposite surfaces of a rail 22 , while a third follower 56 B is oriented to engage the surface of the rail 22 facing into the hatchway 10 . Suitable diameters for the followers 56 A and 56 B are about 1.125 and 1.5 inches (about 2.9 and 3.8 cm), respectively, with smaller and larger diameters being foreseeable. Each set of followers 56 A and 56 B at one end of an arm section 50 is spaced apart from the followers 56 A and 56 B at the opposite end of the same arm section 50 for stability and to ensure that the assembly 40 is capable of vertically traversing the hatchway 10 , preferably while oriented substantially horizontal as represented in FIG. 2 . For this purpose, the sets of followers 56 A and 56 B may be spaced about two feet (about 0.6 meter) apart on each arm section 50 , though lesser and greater separations are foreseeable.
[0018] The cable management assembly 40 is configured to enable the hoist cable 24 to be routed through the assembly 40 via entry and exit points located at longitudinally spaced locations at an upper side 43 of the assembly 40 . The embodiment shown in FIGS. 2 , 3 and 4 is configured to achieve this capability with at least two rollers 58 disposed in a slot 60 defined in the upper side 43 of the middle section 42 . The slot 60 preferably extends entirely through the middle section 42 to the opposite lower side of the section 42 , as evident from FIGS. 3 and 4 . The rollers 58 are rotatably mounted on pins 64 within the slot 60 so that their axes of rotation (as defined by the pins 64 ) are transverse to the longitudinal length of the middle section 42 and, when the assembly 40 is installed as shown in FIG. 2 with the side 43 facing upward toward the car 18 , horizontal with respect to the vertical guide rails 22 . The rollers 58 are spaced within the slot 60 to define two oppositely-disposed openings 62 through which the hoist cable 24 of the temporary elevator car 18 can freely pass to the lower side of the assembly 40 , as represented in FIG. 2 . A suitable diameter for the rollers 58 is about eight inches (about 20 cm), though the use of larger and smaller rollers 58 is foreseeable. Based on the use of eight-inch diameter rollers 58 , a suitable center-to-center spacing between the rollers 58 is about fifteen inches (about 40 cm). In practice, MSD nylon has been found to be a suitable material for the rollers 58 , though the use of other materials is foreseeable. While both rollers 58 are shown as being mounted within the same slot 60 , it is foreseeable that the rollers 58 could be mounted within separate slots in the middle section 42 .
[0019] The cable management assembly 40 is shown in FIG. 2 as being mounted between the elevator guide rails 22 within the pit 32 , though it will be apparent that the assembly 40 can and will be positioned at other locations within the hatchway 10 , depending on the stage of building construction. With the middle section 42 approximately centered between the elevator guide rails 22 , the two end sections 44 are slid out to engage the follows 56 A and 56 B with their respective rails 22 . The two end sections 44 are then locked in place with the bolts 46 . The temporary hoist cable 24 , already fed over the sheave 28 and through the hoist motor 20 on the deck 19 A (consistent with FIG. 1 ), is then fed down past or through the car 18 and to the cable management assembly 40 in the pit 32 . The loose end 30 of the cable 24 is then passed down through one of the openings 62 of the assembly 40 , around both rollers 58 , up through the other opening 62 , and then up through the hatchway 10 to the deck 19 A. The loose end 30 of the hoist cable 24 is wrapped on a spool 66 mounted with a swivel 68 beneath the deck 19 A. The swivel 68 enables the spool 66 to freely rotate, reducing the likely hood that the cable 24 will not properly spool onto the spool 66 . The routing of the cable 24 through the rollers 58 of the cable management assembly 40 provides a two-to-one set up, similar to the two-to-one set up between the hoist motor 20 and working deck 19 A through the sheave 28 on the jump deck 14 .
[0020] FIG. 2 further shows two options for supporting the safety cable 34 . In the first option, the safety cable 34 is routed through the pit 32 and tensioned with the governor tension sheave 38 , similar to that of FIG. 1 . The second option is to attach the tension sheave 38 to the cable management assembly 40 , as shown in FIG. 2 minus the safety cable 34 .
[0021] With the arrangement described above, if the hoist motor 20 is operated to cause the elevator car 18 to travel upward within the hatchway 10 , the temporary hoist cable 24 travels downward through the hatchway 10 to the assembly 40 , around its two rollers 58 , and then upward to the spool 66 beneath the working deck 19 A. If the elevator car 18 travels downward, the hoist cable 24 travels around the two rollers 58 and up through the motor 20 on the working deck 19 A. The hoist cable 24 is essentially a continuous loop starting at the working deck 19 A, through the sheave 28 beneath the jump deck 14 , through the hoist motor 20 on the working deck 19 A, through the car 18 to the cable management assembly 40 , and then back up to the spool 66 beneath the working deck 19 A. Beneath the car 18 , the cable management assembly 40 is secured between the guide rails 22 and suspended by the hoist cable 24 , such that the cable 24 does not lie in the floor of the pit 32 and the assembly 40 tensions the cable 24 .
[0022] When installation of the guide rails 22 and other elevator system components has been completed up to the jump deck 14 , the jump deck 14 is raised (jumped) to a higher floor (not shown) of the building 12 . Because the car 18 would be raised along with the deck 14 during the jumping operation, prior to the jump the safeties on the elevator car 18 are set and the motor 20 is operated to run a sufficient length of the hoist cable 24 upward and out onto the floor of the deck 19 A to enable the jump deck 14 to be raised the desired number of floors above the car 18 . Prior to this operation, a large amount of the temporary hoist cable 24 was under the car 18 and routed through the assembly 40 . As the hoist cable 24 is run out onto the floor of the deck 19 A with the motor 20 , the assembly 40 is raised up out of the pit 32 and through the hatchway 10 until stopped at some distance beneath the car 12 . Concurrently, the governor tension sheave 38 (if mounted to the assembly 40 ) is raised with the assembly 40 .
[0023] Once the jump deck 14 has been jumped and before the elevator car 18 is taken off the safeties and again suspended beneath the jump deck 14 , the cable management assembly 40 is lowered by feeding the remaining length of cable 24 on the working deck 19 A back down through the motor 20 . If attached to the assembly 40 , the governor tension sheave 38 is also lowered to put tension on the safety cable 34 . As such, the hoist and safety cables 24 and 34 are both managed in a safe and secure manner, without placing constructors in hazardous situations over the hatchway 10 or in the pit 32 . Furthermore, the motor 20 can be operated by an elevator constructor standing on the elevator car 18 using a push-button control 72 that allows both cables 24 and 34 to run simultaneously, with the result that the constructors are also able to avoid other common injuries associated with the construction of elevators, such as falling, back injuries, and strains or muscle pulls due to the lifting and carrying of heavy weights.
[0024] While the invention has been described in terms of a preferred embodiment, it is apparent that other forms could be adopted by one skilled in the art. For example, the physical configurations of the cable management assembly 40 , the hatchway 10 , and other aspects of the building construction could differ from those shown, and materials and processes other than those noted could be used. Therefore, the scope of the invention is to be limited only by the following claims.
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A cable management assembly ( 40 ) and method by which cables used to hoist and secure a temporary elevator car ( 18 ) are prevented from becoming tangled as the elevator car ( 18 ) is raised and lowered within an elevator hatchway ( 10 ) during construction of a multistory building ( 12 ). The assembly ( 40 ) is adapted for installation below the car ( 18 ) within the hatchway ( 10 ), and includes a first member ( 42 ) having second and third members ( 44 ) connected at opposite longitudinal ends thereof. A mechanism ( 54,56 A, 56 B) associated with the second and third members ( 44 ) movably engages vertical elevator guide rails ( 22 ) within the hatchway ( 10 ) to enable the assembly ( 40 ) to vertically traverse the hatchway ( 10 ). Another mechanism ( 58,60,62 ) movably and reversibly routs a hoist cable ( 24 ) to and from the assembly ( 40 ).
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent application Ser. No. 12/269,162, filed Nov. 12, 2008, which claims priority under 35 U.S.C. §119 to U.S. Provisional Application No. 60/987,563, filed Nov. 13, 2007, the entire disclosure of which is herein expressly incorporated by reference. The present application is related to U.S. patent application Ser. No. 12/110,471, filed Apr. 28, 2008, the entire disclosure of which is herein expressly incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] A number of factors are driving the health care and wellness industries to move towards comprehensive support of dynamic monitoring of patients and updating their personal records. This new approach to health care, sometimes coined e-health is driven by the need to reduce the cost of patient treatment and the inefficiencies associated with non-critical patients occupying scarce health care resources like hospital beds and nursing among others. The need for e-health is made more urgent by the ageing population in most industrialized countries.
[0003] Electronic transfer of medical records is currently used in hospitals around the world. The Digital Image and Communications in Medicine (DICOM) standard was developed to transfer images and associated patient details between an imaging device (e.g. Ultrasound imaging) and a database. The Health Level 7 standard was developed to track the accounting and visitation records for patients. Other software products are currently used by family doctors to store patient records on their computers. However, with the exception of imaging data, the vast majority of information included in patient records is entered manually. Doctors' and nurses' handwritten notes are often scanned and stored in the patient record.
SUMMARY OF THE INVENTION
[0004] A number of medical and wellness devices are currently used by medical practitioners and end users to monitor various bodily functions, for example, blood sugar levels, blood pressure, oxygen concentration in the blood stream, heart rate, etc. There is a clear need for the automation of the process of recording medical information measured by such devices and others.
[0005] On the other hand, there are strict requirements for the mechanisms that may be used for recording such sensitive information. For example, the mechanisms used must be secure, reliable and in many cases, timely. Sharing patient information with third parties must be done based on strict authorization. Storage of such information must be secure. Finally, a number of performance-related requirements exist if this information is transferred over a wireless system. Efficiency of the information transfer is necessary in order to appropriately utilize the expensive wireless resources. Depending on the capabilities of the wireless device used and the service being provided, other information associated with the user may be necessary, like the user's location and the type of wireless gateway device being used to relay the information from the medical device to the remote server on the Internet. Several other features associated with the authorization of third parties may be needed.
[0006] Exemplary embodiments of the present invention are directed to remotely transferring medical information and updating a patient's record. The present invention is not limited to the health care industry, but it is equally applicable to the wellness industry where users are not sick, but are monitoring their general health, exercise routines or nutrition.
[0007] An exemplary method for a medical device involves obtaining diagnostic information, discovering a gateway device, establishing a connection with the gateway device, establishing a session with the gateway device, and transferring, by the medical device, the diagnostic information to the gateway device.
[0008] An exemplary system includes a medical device that obtains diagnostic information, a gateway device coupled to the medical device, an application server coupled to the gateway device via wired and wireless networks, a database coupled to the application server, the database storing the diagnostic information, and an analyzing device coupled to the database, the analyzing device analyzes records in the database to identify diagnostic information that exceeds predefined thresholds.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0009] FIG. 1 is a block diagram illustrating an exemplary architecture in accordance with the present invention.
[0010] FIG. 2 is a flow diagram of an exemplary method in accordance with the present invention.
[0011] FIG. 3 is a flow diagram of an exemplary method for connection establishment in accordance with the present invention.
[0012] FIGS. 4 and 5 are flow diagrams of exemplary methods for session termination in accordance with the present invention.
[0013] FIG. 6 is a flow diagram of an exemplary method for session establishment in accordance with the present invention.
[0014] FIG. 7 is a flow diagram of an exemplary method for exchange a wait message in accordance with the present invention.
[0015] FIG. 8 is a flow diagram of an exemplary method for session redirection in accordance with the present invention.
[0016] FIG. 9 is a flow diagram of an exemplary method for session multicasting in accordance with the present invention.
[0017] FIG. 10 is a flow diagram of an exemplary method for session establishment in accordance with the present invention.
[0018] FIG. 11 is a flow diagram of an exemplary method for stream initiation in accordance with the present invention.
[0019] FIG. 12 is a flow diagram of an exemplary method for event subscription in accordance with the present invention.
[0020] FIG. 13 is a flow diagram of an exemplary method for an event notification process in accordance with the present invention.
[0021] FIG. 14 is a flow diagram of an exemplary method for retrieving data from an application server in accordance with the present invention.
[0022] FIG. 15 is a flow diagram of an exemplary method for a redirect process in accordance with the present invention.
[0023] FIG. 16 is a flow diagram of an exemplary method for a multicasting operation in accordance with the present invention.
[0024] FIG. 17 is a flow diagram of an exemplary method for session termination in accordance with the present invention.
[0025] FIG. 18 is a flow diagram of an exemplary method for a command message exchange in accordance with the present invention.
[0026] Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] FIG. 1 illustrates the overall system architecture. The system includes medical device 10 coupled by link 20 to gateway device 30 . Medical device 10 comprises hardware and/or software that perform functions related to health care, wellness or nutrition. The device measures biological information about a human or an animal and sends such information out to an application relay function in gateway device 30 via link 20 .
[0028] Link 20 is a wired or wireless link that connects medical device 10 to gateway device 30 . Examples of such link include, but not limited to, Infra-red, Bluetooth, Universal Serial Bus (USB), ethernet, or Wireless Local Area Network (WLAN). Medical device 10 and gateway device 30 may be collocated in the same device, in which case the link 20 is represented by the hardware and software internally allowing those two entities to communicate.
[0029] Gateway device 30 comprises software and hardware components that allow it to communicate, through wired or wireless links, to other devices on the Internet. This device connects medical device 10 to a remote application server 70 using link 20 to a radio antenna 40 connected to Internet 60 . The gateway device also includes the application relay which negotiates the session to the remote application server 70 in order to send information that was earlier sent from medical device 10 or information generated by the application on the gateway device. Gateway device 30 may be connected to the Internet 60 through a wireless network comprising a radio tower 40 and one or many routers 50 . References herein to gateway device 30 in signalling exchanges as a single entity includes the software components inside gateway device 30 that initiates such messages.
[0030] Application server 70 is responsible for receiving and storing information from gateway device 30 , which either originated from medical device 10 or gateway device 30 . The application server also manages the authorization of third parties to view, update, or modify a record. Furthermore, the server is responsible for the management of a session between the server and gateway device 30 , which includes the management of user authentication, authorization, access rights, flow control of data, user profile, among other factors related to a user's subscription or ongoing data transfer. Storage and retrieval of user records stored in database 1000 is controlled by application server 70 .
[0031] Database 1000 stores the user's records. Each record is owned by a user, hereafter referred to as the record owner. The database 1000 is populated by application server 70 . The database may contain intelligence that allows it to search, categorise and manipulate entries for statistical purposes.
[0032] Analyser module 1500 is coupled to database 1000 , and searches through the different records in order to look for abnormalities that can be highlighted to a user viewing such records. This includes looking for measurements that are out of normal ranges based on age, race, and sex of a patient. Entries outside normal ranges may be highlighted for better viewing or can be raised as an alert for the record owner and nominated third parties (e.g. family members, health care practitioners, and so on). Furthermore, such alerts, if they cross predefined thresholds, can be used to contact emergency services on behalf of the record owner. Predefined thresholds for different actions can be configured on a per-user basis. Thus, for example, if information provided by medical device 10 to database 1000 indicates an abnormal heart rate, blood glucose level, etc., analyzer 1500 can identify the abnormality and notify a doctor, hospital and/or ambulance service.
[0033] FIG. 2 illustrates an exemplary method in accordance with the present invention. Medical device 10 connects to gateway device 30 via link 20 (step 405 ). During such connection the application generating the information to be sent on medical device 10 announces its properties and identification to the application relaying the information on gateway device 30 . In addition, other data pertaining to the type of information being sent and its requirements can be exchanged. Following a successful connection establishment, the application on gateway device 30 initiates a session with application server 70 (step 410 ). During the initiation, the application performs the necessary security procedures for authentication and authorization. Furthermore, the application on gateway device 30 can exchange information with application server 70 about the type of data being exchanged and its requirements. This may result in application server 70 commanding the application on gateway device 30 to encode the information in a particular manner.
[0034] Following a successful session establishment between gateway device 30 and application server 70 , information can be relayed from gateway device 30 to application server 70 (step 415 ). Such information includes data received from medical device 10 , as well as, signalling information from gateway device 30 to application server 70 . Information can also be sent from application server 70 to medical device 10 via gateway device 30 . After information has been exchanged between application server 70 and medical device 10 , the session and connection can be terminated (step 420 ).
[0035] As discussed above, medical device 10 and gateway device 30 may be two separate physical devices or collocated within the same physical device. In either case communication between those devices involves connection establishment and data transfer steps. The connection establishment step involves the application on gateway device 30 discovering its peer on medical device 10 and setting up a session between the two peers. In doing so, the application on gateway device 30 needs to first discover its peer, discover its peer's capabilities, then set up a session. The session set up involves exchanging security credentials and the communication port. A communication port may be a logical port on each communicating device, an internet API based socket or any other software module responsible for sending and receiving traffic between the peers. The data transfer step data involves an exchange of data between the two peers. The data encoding and transmission behaviour is exchanged during the discovery and session set-up phases.
[0036] FIG. 3 illustrates the message flow for peer discovery and connection establishment between the application on gateway device 30 and its peer on medical device 10 . The Link_layer_discover 5 message exchange allows the two devices to discover each other's link layer information, such as the link layer address or hardware identification. This message would only take place on the link layer, directly between the two devices if they were sharing the same link or transparently bridged to appear to share the same link. Some link layers (e.g. Bluetooth links) allow for a more sophisticated exchange of information on the link layer. For instance, the Service Discovery protocol (SDP) in Bluetooth allows devices to discover services supported by their peers. For such links, we introduce a new identifier to indicate the support of health services, for instance, the term “vhealth” can be used by medical device 10 to announce that it runs medical or wellness applications. Upon the exchange of link layer discovery and connection information, both devices become aware of each other's link layer details and can send information on that level. Note that as a part of this step, some IP layer messaging in order to discover or configure IP addresses can be exchanged.
[0037] The Device_announce 15 message, allows medical device 10 to announce some of the capabilities that are needed in order for the two applications to start communicating. This message contains, at least, the IP address of the device, and types of medical applications supported by the device.
[0038] In one aspect of this invention, this message is sent on the IP layer. In this case, this message can be encoded as a new Neighbour Discovery option (RFC 4861) for IPv6, or a new Address Resolution Protocol (ARP) parameter for IPv 4 . On point-to-point links, the message can be unicast to the gateway device 30 . However, on shared links, the message should be multi-cast to several nodes on that link. In one aspect of this invention a unique link-local multicast group is used for medical applications. In another aspect of this invention a unique site-local or organisation-local address is used for medical applications. In another aspect of this invention the message is sent to the Well-Known All nodes multicast IP address in IPv6 or broadcast to all nodes on IPv4 links.
[0039] In another aspect of this invention this message is sent by the application layer. Where TCP/IP is used for this communication, the application on medical device 10 can send this message to a reserved, well-known port, or a preconfigured port for the application relay on gateway device 30 . If TCP/IP is not used for this communication, applications on medical device 10 can send this message to a negotiated or preconfigured communication port. In yet another aspect of this invention this message can be added to link layer exchanges during the link layer discovery phase or after configuring an IP address for communication. After processing message 15 , gateway device 30 detects medical device 10 and its application capabilities as illustrated by the device detected block 25 .
[0040] After discovering medical device 10 on the link layer and potentially the IP or application layers, the application relay on gateway device 30 announces itself in the Relay_announce message 35 sent to the medical device. This message serves to acknowledges the reception of message 15 and announce the application relay's capabilities to medical device 10 . This message includes, at least, the application relay's IP address and port. The application relay's IP address is one of the IP addresses configured on gateway device 30 . If no IP address is configured, the link layer and communication port information should be announced instead. The application relay's port identifies the communication port, represented by name or number, that the application relay expects its peer on medical device 10 to send its information.
[0041] On point-to-point links, the message is sent directly from gateway device 30 to medical device 10 . However, on shared links, the message may be sent gratuitously to a unique multicast group that includes all medical devices. The scope of such group may be link-local, site or organization-local. However, when responding to a specific medical application device, the application relay on gateway device 30 may unicast this message to the medical device in order to include the acknowledgement information for the Device_announce 15 message. This message may be sent on the IP layer (for both IPv4 and IPv6), the application layer, or the link layer.
[0042] In the Authentication step 45 mutual authentication between the two applications takes place. In one aspect of this invention, mutual authentication can be based on preconfigured credentials in medical device 10 and gateway device 30 . In another aspect of this invention, mutual authentication can be performed based on Public keys configured in both applications and exchanged during message exchange 45 .
[0043] The Identification message 55 is then sent from the application running on medical device 10 to its peer application relay running on gateway device 30 . The message includes, at least, the following information:
The application identifier field, which contains information that identifies the application. The information included in this field would contain at least the following:
Application type parameter, which indicates the functions supported by the application. For instance, an application may be used to measure an electro-cardiogram, heart rate, kidney functions, and so on. Each application is allocated a name or a number that can be used by the receiver to detect the type of application. Application vendor parameter, which indicates the vendor of the application. Different vendors may have different formats for the data. Data encoding parameter, which indicates the data encoding scheme. For instance, the data may be sent in binary format, text format, XML, and so on. Data compression parameter, which indicates whether a compression mechanism, if any, is used to send the data, and if it is, the mechanism is identified. Quality of Service (QoS) information field, which includes information about the traffic behavior sent by the application. This includes expected packet inter-arrival, delay tolerance, reliability requirements, packet ordering requirements, and so on.
The software version supported by the application. This information allows the relay agent to learn the software supported by medical device 10 application. The data encoding formats supported by the application on the medical device. Compression mechanisms supported by the application running on medical device 10 .
[0053] The Id_ack 65 message is sent from the application relay running on gateway device 30 to medical device 10 . This message acknowledges the reception of the identification message and informs the application on medical device 10 whether a session can be established. If a session can be established, this message contains a session identifier that can be used by the application running on medical device 10 during data transfer. Moreover, as described below, additional information about attributes for the data flow is included in this message. The session identifier can be included in every message sent from the application on medical device 10 to the application relay on gateway device 30 to allow the application relay to identify the session associated with the data transmitted. The session identifier can also be used as a look-up key when data between the two devices is encrypted on the application layer. This message can be authenticated and encrypted based on the keying material derived after the authentication message exchange 45 . Hence, this message contains, at least, the following information:
Acknowledgement for receiving the Identification message 55 . If session establishment is successful, a session identifier is included. The session identifier may be a 64-bit number. This number may be randomly generated or selected by the application relay by other means. If session establishment failed, an appropriate error code is included. Authentication and encryption data used to authenticate this message by the receiver. Selection of the application relay's preferred data encoding format for data sent by the application on medical device 10 . This is needed when the application on the medical device supports multiple formats while the application relay prefers a specific format or supports a smaller number of formats. Compression requirements parameter, which informs the application on medical device 10 whether compression should be used and if it is, what compression mechanism should be used.
[0060] Now that the discovery and connection establishment processes has been presented, the processes associated with data transmission between the application running on medical device 10 and the relay application on gateway device 30 is discussed in detail below.
[0061] Based on the data format preferences exchanged between medical device 10 and gateway device 30 during the discovery process encompassing the Identification 55 and Id_ack 65 messages, gateway device 30 commands medical device 10 to use one of its preferred formats for data transfer. After a session is established, medical device 10 can start transmitting information to gateway device 30 . Regardless of the data format, each packet contains the following information:
Source address. Destination address. Session identifier. A message identifier parameter that uniquely identifies a message within a session. This can be represented by a large number used as a counter. Communication ports. The application identifier (optional). Amount of information waiting for transmission. An urgent alert parameter that alerts the application relay that there may be a medical emergency that needs attention based on the measurements performed. This parameter need not hold binary values. There may be different levels of urgency that need to be communicated. A device may be running out of battery power and needs to send data as soon as possible. Similarly, a device may be lacking other resources and therefore needs to send data to free some of its resources. Hence, this parameter may hold various values depending on the level of urgency experienced. A data parameter that contains information generated by medical device 10 .
[0071] Exemplary embodiments of the present invention employ signalling messages exchanged between the application on medical device 10 and gateway device 30 to convey information about the data exchanged or the session as a whole.
[0072] Session termination may take place due to several reasons, including lack of resources, lack of data to send, errors in transmission, and so on. Either the application on medical device 10 or gateway device 30 can terminate the session at any time. FIGS. 4 and 5 illustrate how session termination can take place when initiated by either end of the communication.
[0073] When terminating the session, the application on medical device 10 sends the Session_Terminate 75 message to the application relay on gateway device 30 . The Session_Terminate 75 message contains, at least, the session identifier and reason for termination. The session identifier parameter is the same parameter provided by the application relay when the session was established. This parameter is used by the receiver to identify the session being terminated and the resources associated with such session. The reason parameter indicates the reason for terminating the session. There may be several reasons for the termination including: idle timeout, no measurements being done, lack of resources, communication errors, and so on.
[0074] After sending this message, the sender may maintain some of the resources associated with the session in order to identify the acknowledgement message from the receiver. For instance, the session identifier may not be deleted until an acknowledgement is received or a timeout takes place.
[0075] Upon receiving this message, the receiver identifies the session and its resources. The receiver then takes the necessary steps to terminate the session and free its resources. Following that, the receiver then sends the Terminate_Ack message 85 to the sender. The Terminate_Ack message 85 includes the session identifier and status parameters. The session identifier parameter is the same parameter included in the Session_Terminate message 75 . The status parameter indicates the success or failure of the operation and reasons for failure. If the Terminate_Ack message 85 is received indicating failure at the other end, the receiver of such message may ignore such failure and remove all resources associated with the session.
[0076] FIG. 5 illustrates how a session can be terminated by the application relay on gateway device 30 . The same steps described above would apply to the termination initiated by gateway device 30 .
[0077] In some cases, mostly due to erroneous state management in one of the communicating entities, a peer may send a message that contains an unrecognisable session identifier. This situation may also happen if one of the peers lost state due to a reboot or corruption of its memory. In this case, the receiver sends the “Session_unknown” message 90 back to the sender. This message contains the session identifier received. Upon receiving such message, the sender of the original message may remove the session corresponding to that message identifier in order to synchronise states with its peer. This mechanism may be used with a reserved session identifier value to indicate to a peer that the device has lost all states with such peer. Hence, this message can be used by either the medical application or the application relay to communicate general loss of state to its peer.
[0078] The medical application running on medical device 10 may at any time need to create a new session. For instance, this can be useful if such application sends several independent streams of traffic that can be separated under different sessions. In order to do that, the message exchange in FIG. 6 is performed, which involves sending a New_Session message 95 from medical device 10 to gateway device 30 and receiving a New_Ack response by medical device 10 from gateway device 30 . The New_Session message 95 may also be sent from gateway device 30 to medical device 10 . The New_Session message 95 requests a new session identifier from the application relay. The message includes, at least, the following parameters:
Source and destination addresses. Source and destination communication ports. Session identifier parameter, which is the new session identifier requested by the sender. It includes a suggested session identifier. Application identifier parameter, which includes the application identifier previously included in the Identification message 55 .
[0083] Upon receiving this message, the recipient parses the message to ensure all fields are formatted correctly. If there is no conflict between the suggested session identifier in the message and an existing session identifier, the suggested identifier is accepted. Otherwise, the message is rejected with a suitable error code in the New_Ack message 97 . The New_Ack message 97 includes, at least the following information:
Source and destination addresses. Source and destination communication ports. Result parameter, which indicates success or failure of the operation. Different error codes can be used to indicate reasons for failure.
[0087] The protocol between the medical device application and the application relay on gateway device 30 can use a reliable mode of data transfer by using acknowledgement messages. The acknowledgement message can be sent from either the medical application or the application relay in order to confirm reception of one or more data or signalling messages. The acknowledgement message can also act as a negative acknowledgement by including one or more message that was not received. The acknowledgement message includes, at least, the following information:
Source and destination addresses Source and destination communication ports Session Identifier Message identifier Acknowledgement type parameter, which indicates whether a positive or negative acknowledgement is included in this message. Message identifiers parameter, which includes on or more message identifiers that are being positively or negatively acknowledged. Transmission Window field, which indicates the number of bytes that the sender can receive without sending back an acknowledgement message.
[0095] Flow control can be critical for cases where a large amount of information is sent from the medical application running on medical device 10 to the application relay running on gateway device 30 . It is important for the application relay to regulate the flow of traffic to avoid congestion. The Transmission Control Protocol (TCP) provides native flow control mechanisms. However, TCP may or may not be used between the two applications. Furthermore, this invention allows more than one device to be connected to the gateway device. Hence, it is critical that application relay on gateway device 30 prioritizes and regulates flow control from different devices.
[0096] In order to regulate the flow from a single medical application, the application relay includes the Transmission Window parameter in its Acknowledgement messages sent to the medical application. This Transmission Window size informs the medical application that it can transmit the included number of bytes without waiting for an acknowledgement. After sending that number of bytes, the medical application waits for an acknowledgement message. If that acknowledgement message only contains the last received message, it is an indication to the medical application that all messages sent since the last acknowledgement was sent. Upon receiving this, the medical application can reset the window size and start transmitting new data.
[0097] FIG. 7 illustrates an exemplary message exchange used to slow down or temporarily stop the information transfer between the medical application and its peer, the application relay. The Wait message 105 is sent from the application relay to the medical application on medical device 10 . The Wait message 105 commands the medical application on medical device 10 to reduce the rate of information transmission or stop it for a period of time. Hence, the message contains the following parameters:
Source and destination addresses. Source and destination communication ports. Session identifier. Message identifier. Transmission window size parameter, which includes the new transmission window for future messages. A transmission window size of zero indicates that the medical application should stop sending messages and buffer information until a larger value is sent in the transmission window parameter. A new Wait message 105 or an Acknowledgement message can overwrite this transmission window by including a higher or lower value.
[0103] The Wait_Ack message 110 is sent from the medical application on medical device 10 to the application relay on gateway device 30 . The purpose of this message is to acknowledge the receipt of the Wait message 105 . If the medical application is requested to stop transmission for a period of time (by including a value of zero in the transmission window parameter) the medical application may choose to send a buffer-size parameter in the Wait_Ack message 110 , which indicates how long it can buffer packets. The buffer-size parameter can be represented by time units or number of bytes. Hence, the Wait_Ack message 110 includes, at least, the following parameters:
Source and destination addresses. Source and destination communication ports. Session identifier. Message identifier. Buffer-size.
[0109] The application relay running on gateway device 30 may command the medical application on medical device 10 to redirect one or more sessions to a new peer using the session redirection exchange illustrated in FIG. 8 . This may be done for load-balancing, to obtain better access to the Internet, or to send session information to another entity that needs it more urgently (e.g. a physician, paramedic, and so on). The redirection command may be triggered by a command sent to the application relay from a remote entity or due to manual intervention by the user.
[0110] Based on, optionally, an external input 1 , the application relay on gateway device 30 may decide to send the Session_Redirect message 115 to the medical application on medical device 10 , with which a session already exists. The Session_Redirect message ( 115 ) contains, at least, the following information:
Source and destination addresses. Source and destination communication ports. Session identifier. Message identifier. New peer parameter, which includes the reachability information of the peer that the medical application is being redirected to. This may include an address and communication ports. Redirected sessions parameter, which includes the session identifiers for those sessions that need to be redirected to the new peer. Authentication credentials for the new peer parameter, which is optional, and includes the credentials of the new peer of the medical application on medical device 10 .
[0118] Upon receiving the Session_Redirect message 115 , the medical application checks the session identifier parameter. If the session identifier does not match an existing session, an error code can be included in the Redirect_Ack 120 message. Alternatively, the medical application may send a Session-unknown 90 message including the session identifier. However, if the session identifier were valid, the medical application starts the authentication process with the new peer. If the peer's full reachability information were not provided the medical application may have to start the discovery phase presented in FIG. 3 .
[0119] Following the processing of the Session_Redirect message 115 , the medical application sends the Redirect_Ack 120 message. This message includes at least the following information:
Source and destination addresses. Source and destination communication ports. Session identifier. Message identifier. Result field, which indicates whether the redirection of the session was successful or not and the reasons given for failure.
[0125] If the redirection was not successful the application relay may command the medical application to try again, or, alternatively, continue receiving traffic in this session. If the redirection was successful, the session is closed.
[0126] The application relay on gateway device 30 may command the medical application on medical device 10 to multicast one or more sessions to several peers, which may include the application relay sending this message. Such data duplication can be useful when several entities need to store or observe particular information coming from the medical application on medical device 10 . Like the Session_Redirect message, session multicasting can take place as a result of a command from a remote server or manual intervention by the user. In order to order session multicast, the application relay on gateway device 30 sends the Session_Mcast message 125 as shown in FIG. 9 .
[0127] The Session_Mcast message 125 contains at least the following information:
Source and destination addresses. Source and destination communication ports. Session identifier. Message identifier. New peers parameter, which provides reachability information for the peers that the medical application needs to multicast sessions to. This may include addresses and communication ports. The application relay sending this message may also include its own reachability information to indicate that it should continue to receive traffic for the multicast session. Session identifiers parameter, which includes one or more session identifier that identifies session that need to be multicast to the new peers. An implementation may choose to only include one session identifier per Session_Mcast message. In this case, if multiple sessions need to be multicast, multiple Session_Mcast messages will need to be sent, each as part of the session being multicast. Authentication credentials for new peer's parameter, which includes multiple authentication credentials, one for each peer. This parameter is optional.
[0135] Upon receiving the Session_Redirect message 125 , the medical application on medical device 10 checks the session identifier parameter. If the session identifier does not match an existing session, an error code can be included in the Mcast_Ack 130 message. Alternatively, the medical application may send a Session_unknown 90 message including the session identifier. However, if the session identifier were valid, the medical application starts the authentication process with the new peers. If the peers' full reachability information were not provided the medical application may have to start the discovery phase presented in FIG. 3 .
[0136] Following the processing of the Session_Mcast message 125 , the medical application sends the Mcast_Ack 130 message. This message includes at least the following information:
Source and destination addresses. Source and destination communication ports. Session identifier. Message identifier. Result parameter, which contains the result of the operation and indicates success or failure. If the operation failed for some peers, such peers would be included in this message. If the operation failed for entire sessions, those session identifiers would be included.
[0142] Now that the messaging between the medical device and gateway has been described, the messaging between gateway 30 and application server 70 will be discussed. Messages exchanged between those two entities can be divided into two categories: 1) Signalling messages and 2) data messages. Signalling messages deal with session initiation, which includes server discovery, session control, and session maintenance. Data messages are packets that include data exchanged between gateway device 30 and application server 70 .
[0143] Initially, gateway 30 employs a server discovery process to discover the address of application server 70 and initiate a new session. This process is illustrated in FIG. 10 . Gateway device 30 starts the discovery process by obtaining the IP address of application server 70 as represented by block 135 . In one aspect of this invention, this can be done through manually configuring the IP address in gateway device 30 . In another aspect of this invention the IP address can be obtained dynamically using the Domain Name System (DNS) (RFC 1033, RFC 1034, RFC 1035) or the Dynamic Host Configuration Protocol for IPv4 or IPv6 (RFC 2131 and RFC 3315).
[0144] After the IP address of application server is obtained, the application on gateway device 30 sends a session_init message 140 . This message contains, at least, the following parameters:
The source and destination addresses The source and destination communication port numbers. This is typically the port number identifying the communication sockets when using the TCP/IP communication suite. The user's identifier. This parameter is either a unique alphanumeric string or number that identifies the user that owns an account on application server 70 .
[0148] This message starts the authentication process 145 where both gateway device 30 and application server 70 authenticate each other. After a successful authentication phase, the application server sends the init_ack 150 message. This message is authenticated based on the credentials derived from the authentication phase 145 and contains, at least, the following information:
The source and destination addresses The source and destination communication port numbers. This is typically the port number identifying the communication sockets when using the TCP/IP communication suite. The user's identifier. This parameter is either a unique alphanumeric string or number that identifies the user that owns an account on application server 70 . The session identifier, which is a unique number chosen by application server 70 . Record indices. This is an optional parameter sent from application server 70 to gateway device 30 to provide it with the indices used by the server to identify parts of the user's record. These indices can be used later by gateway device 30 to create or update entries in the user's record. Indices are essential to inform the server where such entries should be stored (i.e. under what category). Application server's address parameter, which may include a different address from that used by the sender of this message. Essentially, this parameter can be used by the sender to redirect the application on gateway device 30 , to another server. This may be done for load sharing, or to separate the servers handling the signalling messages from those receiving payload data. Authentication and encryption data. This parameter includes the data needed by the receiver to authenticate and decrypt the message.
[0156] A session may contain one or more streams that correspond to different types of information being exchanged between gateway device 30 and the application server 70 . When initiating a new stream, gateway device 30 indicates the type of information intended for such stream by including the application identifier parameter. This parameter allows application server 70 to identify the information and allocate the necessary resources for it. FIG. 11 illustrates the stream initiation process. The application on gateway device 30 sends the stream_init 155 message. This message is authenticated based on the credentials derived from the authentication phase 145 . The message contains, at least, the following information:
The source and destination addresses The source and destination communication port numbers. This is typically the port number identifying the communication sockets when using the TCP/IP communication suite. The user's identifier parameter, which is either a unique alphanumeric string or number that identifies the user that owns an account on application server 70 . The application identifier. This is the application identifier presented earlier in the Identification message 55 . The payload label parameter, which is optionally included in the message and contains an alphanumeric string that includes the label for the payload information sent in this session. The label may be manually added by the user or automatically generated by the application on gateway device 30 . This label can be a readable string that allows users to later distinguish different entries in their records. The latest version supported by the application on gateway device 30 . Authentication and encryption data.
[0164] Upon receiving this message, application server 70 sends the stream_ack 165 message. This message is authenticated by the credentials derived from the authentication phase 145 . This message contains, at least, the following information:
The source and destination addresses The source and destination communication port numbers. This is typically the port number identifying the communication sockets when using the TCP/IP communication suite. The session identifier. A stream identifier parameter, which identifies a particular stream within a session. A session may contain one or more streams corresponding to different sets of information being sent by gateway device 30 . The stream identifier is then used by gateway device 30 in each payload packet. The storage identifier parameter, which identifies the part of the user's record where the information needs to be stored. The identification of the part of the user's record that will contain this information may be done manually (by the user) or inferred by the server based on the application identifier information sent in the stream_init 155 message. Result parameter, which contains the result for the operation which indicates either success or failure and the reason for such failure. Authentication and encryption data.
[0172] Gateway device 30 may at any time subscribe to a particular event. Examples of events include comments that may be added to the profile, messages, alerts of any kind and reminders. In order to subscribe, the gateway device sends a subscription request message 185 to the application server. FIG. 12 illustrates this message exchange. The Subscribe message is sent from the Gateway device to the application server. It contains the following information:
Source and destination addresses Source and destination communication ports Session identifier Event descriptor parameter, which includes either an index to a particular event or a string that describes the event. Authentication and encryption data.
[0178] The application server responds with the Subscribe_Ack 195 message to gateway device 30 . This message includes the following information:
Source and destination addresses Source and destination communication ports Session identifier Status parameter, which includes information that indicates success or failure of the operation. In case of failure, reasons are specified. Authentication and encryption data.
[0184] When a particular event that the gateway device subscribed to takes place, the application server sends a Notify message. Different events may address different needs. Some events address the user, other address the application software and may be transparent to the user. The application server may send a readable message to the user instead of, or in addition to the Notify message. Examples of readable messages include the Short Message Service (SMS) or electronic mail (e-mail). FIG. 13 illustrates this message exchange. Initially, a Notify message 205 is sent from application server 70 to gateway device 30 . This message informs the gateway device that an event, for which the device has subscribed, has taken place. The Notify message contains the following information:
The source and destination addresses Source and destination communication ports Session identifier. Event parameter, which describes the event that took place. This can be done by simply including an index representing the event, user readable text for display. Authentication and encryption data.
[0190] The Gateway device responds to the Notify message 205 with a Notify_ack message 215 . The Notify_ack message contains the following information:
The source and destination addresses Source and destination communication ports Session identifier. Status parameter, which indicates success or failure of the operation. Depending on the content of the message, the server may take further action. Authentication and encryption data.
[0196] The application server 70 may send a readable message 220 instead of, or in addition to the Notify message 205 . Acknowledgement of such message depends on the protocol being used to send the message.
[0197] User records can be retrieved by gateway device 30 or any other viewing device that the user may choose. For simplicity, gateway device 30 is described as the retrieving device. In order to retrieve records, the gateway device needs to request top level indices for the record. This refers to the main sections in the record, each identified with a unique index. The gateway device can then request child records. Child records are subsets of the main sections represented by the top level indices. Each top level index is identified by a name that may be represented as a string. In addition, each entry (including top level and child records) can be associated with a number of attributes that describe the format of the data included in the entry, dates, and other logs associated with such data.
[0198] All types of entries can be retrieved from application server 70 using the Retrieve message 230 . This message requests one or more entries. The message exchange for retrieving records is illustrated in FIG. 14 . The Retrieve message 230 contains the following information:
The source and destination addresses. The source and destination communication ports. The session identifier. The stream identifier. Data retrieval request parameter, which identifies the data to be retrieved by gateway device 30 . This parameter can indicate a request to retrieve a specific entry in the user record, a group of entries (e.g. all parent entries), or all entries in the user's record. Authentication and encryption data parameter, which includes data that can be used to verify the authenticity of the message and decrypt it.
[0205] Upon processing the retrieve message, application server 70 sends the retrieve_ack message 240 . This message contains the following information:
The source and destination addresses. The source and destination communication ports. The session identifier. The stream identifier. Status parameter, which indicates success or failure of the operation. Entry ports parameter, which informs the gateway device of which entries may need to be retrieved from other communication ports or network addresses. For instance, application server 70 may tell gateway device 30 to retrieve some entries as files, using the file transfer protocol (FTP). In this case, such information would be included in this parameter and the gateway device would then retrieve those entries from the addresses or communication ports provided by application server 70 . Data parameter, which contains some or all of the entries requested by gateway device 30 . If the requested entries could not be sent in this message (e.g. too long for one message), then the application server will send them in separate messages. These messages are highlighted by the “Data Exchange” line in FIG. 14 . Authentication and encryption data parameter, which includes data that can be used to verify the authenticity of the message and decrypt it.
[0214] After receiving the retrieve_ack 240 message, the gateway device will be able to receive data from the application server. Data transferred between the application on gateway device 30 and application server 70 takes place after a session and a stream are established. Each packet transferred between those two entities contains information about the sender and the receiver, whose IP addresses was conveyed to the application on gateway device 30 during the session establishment process. In addition, each packet contains the session identifier, the stream identifier, and information about the payload contained in the packet. The type of payload can either be inferred from the application identifier exchanged during session establishment or included in each packet. Additionally, the operation required is included in the packet carrying the payload. The operation may request the application server to create a new entry, update an existing entry, or delete and entry. Other operations can be added to the protocol as needed.
[0215] The data transferred between the application on gateway device 30 and application server 70 can use any transport protocol mechanism, like the User Datagram Protocol (UDP), the Transmission Control Protocol (TCP) or other transport protocols. A payload data packet contains the following information:
The source and destination addresses. The source and destination communication ports. The version of the protocol being used. The session identifier. The stream identifier. Packet identifier parameter, which uniquely identifies a packet within a stream. When combined with the stream identifier it uniquely identifies a packet within a session. Operation parameter, which indicates the type of operation requested for the payload. For instance, this indicates: create entry, update entry, or delete entry. Indication of fragmentation parameter, which indicates whether the payload included is a fragment of larger pieces of information, and if so, its order, or that the payload includes all of the data transferred. Payload Data field, which includes user generated, gateway device generated, or medical device generated data that is transferred to application server 70 . Authentication and encryption data.
[0226] Data sent from gateway device 30 or application server 70 is acknowledged by the receiver using the acknowledgement message. This message contains, at least, the following information:
Source and destination addresses. Source and destination communication ports. Session identifier. Stream identifier Packet identifier. Acknowledged fragments parameter, which contains one or more fragment numbers that are being acknowledged by the application server. The fragment numbers are obtained from the Indication of fragmentation parameter described above. This parameter may simply contain the last received fragment, which would indicate that every fragment up to the one included in this parameter was received correctly. Authentication and encryption data.
[0234] The application server 70 can order the client to redirect a session to another server. The redirection may order the application on the gateway device to re-authenticate itself to the new application server, or simply continue transmission provided that authenticated acknowledgements are received from application server 70 . Redirection can also be done for a particular request. For instance, the gateway device may request a particular operation that cannot be met by the current application server 70 ; application server 70 can redirect gateway device 30 to another server that can fulfil its request. However, this does not necessarily mean that future request will automatically go to the new server. Hence, the redirection process can be permanent, or done on a task-by-task basis. The redirection message exchange is illustrated in FIG. 15 .
[0235] The Redirect message 250 can be sent by either gateway device 30 or application server 70 . When this message is sent from application server 70 to gateway device 30 it is based on either an external event, or a request from gateway device 30 . The Redirect message contains the following information:
The source and destination addresses. The source and destination communication ports. The version of the protocol being used. The session identifier. The stream identifier. Reason parameter, which indicates the reason for the Redirect message. The reason can indicate non-availability of a service, entry retrieval, change in network conditions, and administrative policy among other reasons. This parameter also indicates whether the change is permanent, i.e. redirecting the entire session, the stream, or only for a particular request that can be best met by another server. Redirection information parameter, which provides the necessary information for the receiver in order to be able to establish a connection with the new entity. Examples of such information include the new entity's IP address, transport protocol (e.g. UDP or TCP) and the port number that should be used. This parameter also indicates whether a new security association needs to be established. Authentication and encryption data.
[0244] After processing the Redirect message 250 , the receiver sends the Redirect_ack message 260 , which contains the following information:
The source and destination addresses. The source and destination communication ports. The version of the protocol being used. The session identifier. The stream identifier. Status parameter, which indicates success or failure of the operation. In case of failure, this parameter indicates the reason for failure. Authentication and encryption data.
[0252] Session multicasting involves the request from either gateway device 30 or application server 70 for the other end to send the information to multiple entities. The gateway device may request the server to send data to multiple devices, including itself. The same request can come from application server 70 to gateway device 30 in order to allow other entities to receive information. The multicasting request-response process is shown in FIG. 16 . For simplicity, we only show the case where the request is made by application server 70 . However, the reverse can also be true. The Mcast message 270 contains the following information:
The source and destination addresses. The source and destination communication ports. The version of the protocol being used. The session identifier. The stream identifier. Reason parameter, which indicates the reason for the Mcast message. The reason can indicate emergency, multiple viewing devices or administrative policy among other reasons. This parameter also indicates whether the change is permanent, i.e. redirecting the entire session, for this stream, or only for a particular request. Multicasting information parameter, which provides the necessary information for the receiver in order to be able to establish a connection with the new entities. Examples of this data include the IP address of the new entity, the protocol to be used (e.g. UDP or TCP) and the port numbers. This parameter also indicates whether a new security association needs to be established. Multicast off parameter, which is used to request that the receiver stop multicasting the session or stream that was being multicast. This parameter is only added when the sender wishes to stop an existing multicast. Stopping a multicast implies that the multicast traffic is unicast to the original receiver before multicasting started. Authentication and encryption data.
[0262] Upon successfully processing the Mcast message 270 , the receiver sends the Mcast_ack message 280 to acknowledge reception. The Mcast_ack message 280 contains the following information:
The source and destination addresses. The source and destination communication ports. The version of the protocol being used. The session identifier. The stream identifier. Status parameter, which indicates success or failure of the operation. If the operation failed, this parameter would indicate the reason for failure. Authentication and encryption data.
[0270] Either gateway device 30 or application server 70 can terminate a session at any time. Session termination implies the termination of all streams within the session. Termination can also be done for one stream within a session while keeping the rest of the session active. Termination is done by sending the Term message 290 . This message can originate in gateway device 30 or application server 70 . FIG. 17 illustrates the case where it originates from the application server. The Term message 290 contains the following information:
The source and destination addresses. The source and destination communication ports. The version of the protocol being used. The session identifier. The stream identifier parameter, which is included if one stream is being terminated while the session remains active. Reason parameter, which specifies a reason for terminating the session. Authentication and encryption data.
[0278] Upon receiving the Term message 290 , the receiver constructs the Term_ack message 300 and sends it. The Term_ack message 300 contains the following information:
The source and destination addresses. The source and destination communication ports. The version of the protocol being used. The session identifier. Status parameter, which specifies the result of the operation. In some cases the termination operation may fail, which results in the sender repeating the process. However, in other cases the sender may ignore the operation's failure and simply terminate the session at its end. Authentication and encryption data.
[0285] At any point in time after a session is established, application server 70 may send a command to gateway device 30 that can either demand a certain action from the gateway device or from medical device 10 . If the command requests an action by medical device 10 , it is relayed by gateway device 30 to medical device 10 . The command may contain any action deemed necessary by the application server. For instance, application server 70 may need medical device 10 to perform a certain lifesaving action like defibrillation or other actions needed by the user. The command message 320 is illustrated in FIG. 18 . The Command message 320 contains the following information:
The source and destination addresses. The source and destination communication ports. The version of the protocol being used. The session identifier. The stream identifier parameter, which is included if a stream is established and the Command message is related to the established stream. Command parameter, which contains a description of the command sent from application server 70 . Authentication and encryption data.
[0293] The Command_ack message 330 is sent from gateway device 30 to acknowledge the reception of the command message 320 . It contains the following information:
The source and destination addresses. The source and destination communication ports. The version of the protocol being used. The session identifier. The stream identifier parameter, which is included if it were included in the command message 320 . Status parameter which, specifies the success or failure of the operation and reason for failure. Authentication and encryption data.
[0301] If the Command message 320 requested an action by medical device 10 , gateway device 30 will relay the command to medical device 10 using the Comm message 340 . The Comm message contains the following information:
The source and destination addresses. The source and destination communication ports. The version of the protocol being used. The session identifier parameter, which includes the session identifier for the session set-up between medical device 10 and gateway device 30 . The message identifier. Command parameter, which describes the command sent from application server 70 . Authentication and encryption data.
[0309] Medical device 10 acknowledges the reception of the Comm message 340 by sending the comm_ack message 350 . The comm_ack message contains the following information:
The source and destination addresses. The source and destination communication ports. The version of the protocol being used. The session identifier. The message identifier. Status parameter, which specifies success or failure and the reason for failure. Authentication and encryption data.
[0317] Exemplary embodiments of the present invention allow application server 70 to detect the presence of a medical emergency that requires alerting a medical emergency service or physician, or a nominated person or all of the above. Detecting an emergency can take place if application server 70 is explicitly notified by gateway device 30 (possibly due to a notification by medical device 10 ) or by analysing the data sent from gateway device 30 and deciding that a medical emergency exists.
[0318] Gateway device 30 can indicate an emergency while sending medical information, relayed from medical device 10 or due to manual intervention by the user. On the other hand, application server 70 can detect an emergency by analysing the medical data coming from gateway device 30 . Such analysis may be routinely made when a stream is set-up for certain types of devices (known from the application identifier) or due to a request by the user, or due to certain configuration on the user's account. For instance, a user that may need close attention (a recovering patient or a high risk one) may have an account configuration that requires continuous monitoring of all data sent from his or her medical device.
[0319] Depending on the settings in the user's account, an emergency situation may be handled differently. An application server may alert certain parties of the need for attention to the user's data. Alternatively, the application server may notify such parties as well as notifying an emergency service, e.g. ambulance service to get to the user. In the latter scenario, the user's location would be collected from the gateway device. The user's location can be obtained through the knowledge of the geographical location using a positioning system (e.g. satellite based systems like GPS or triangulation techniques in cellular networks), the Internet topology where the user is located, the access point to the Internet that the gateway device is connected to, or a combination of all of this information.
[0320] User records contain health information that is manually or automatically added by the user or gateway device 30 , respectively. Examples of health information include the following:
Medical history: including the user's previous illness, surgeries, accidents or any other event in the past that affected the user's health. Medications: including any prescription or non-prescription medication that the user is taking. This also includes allowing the user to renew prescriptions online. Scans: including any scans received like X-rays, ultrasound information, CT-scans, MRI, and any other types of scans related to cardiology health. Pathology: including any laboratory results done for the user. Nutritional diary: including the user's nutritional diary, food consumption, the user's height and weight, and the amount of nutrients in the user's food, including calories. This record may also contain the ingredients of food consumed by the user. Exercise diary: including the user's exercise diary, like running, swimming, walking or any other exercise activity. Each exercise session can contain several attributes related to the user's physical functions during exercise. A simple example of such attributes includes the user's heart rate. Such measurements can be taken regularly during exercise and sent to application server 70 from medical device 10 , through gateway device 30 . Measurements: including any measurements related to the user's health that are added automatically by gateway device 30 or manually added by the user. Family history: including any hereditary illnesses like heart disease, that affected the user's family members. Doctor's comments: including any comments added by the user's physicians or health practitioners. Toddler records: including information about toddlers in the user's family. This includes any information related to the toddler's health, height, weight, vaccinations, illness, and so on. Subscribed Services: including the services that a user is subscribed to receive. Biometric information: including any biometric information that can be used to identify the user. Examples include retinal scans, fingerprints, DNA information or any other information. User's identification: including user identification information like scans of a driver's license, passport, or any other photographic or non-photographic identification. Personal settings: including the user's personal settings and preferences. This may include display settings, language preferences, choice of whether the user wants to receive alerts other than those subscribed, and so on. Medical library: including interesting articles that may be relevant to the user's medical records.
[0336] Each of the above headings within a user's record contains zero or more entries. Each entry has attributes that define read and write authorization. In other words, each entry can be read or modified based on the authorization level of the user. Hence, different entities viewing the user's record may be able to read or modify subsets of the record. As a result of this architecture, the record owner may associate different entities with different levels of authorization. This allows the record owner to allow different health practitioners to view different parts of his or her medical records.
[0337] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.
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Systems and methods of providing telemedicine services are provided. A system can include a medical device that obtains diagnostic information, a gateway device coupled to the medical device, an application server coupled to the gateway device via wired and wireless networks, a database coupled to the application server, the database storing the diagnostic information, and an analyzing device coupled to the database, the analyzing device analyzes records in the database to identify diagnostic information that exceeds predefined thresholds.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
It is estimated that approximately 25% of our harvested fruits and vegetables are lost to postharvest diseases. In the past, synthetic chemical fungicides were relied upon for the control of such diseases; however, as concerns over the health risks posed by these chemicals have increased, many of them have been withdrawn from use by regulatory agencies as well as a result of consumer pressure. In addition, an increased resistance to fungicide treatment by the pathogens responsible for postharvest diseases has been observed. Thus, there is a strong incentive to develop safe and effective alternatives to chemical fungicides. This invention relates to a composition which provides such an alternative by utilizing an antagonistic microorganism (Candida saitoana) in combination with the sugar analog, 2-deoxy-D-glucose (2-DG).
2. Description of the Prior Art
The biological control of postharvest diseases by antagonistic microorganisms has become increasingly important with the advent of tighter controls on the use of chemical additives on agricultural food commodities. As a result, a number of investigators have applied compositions containing such microorganisms to agricultural commodities with some success.
The bacterium Bacillus subtilis has been shown to inhibit a variety of diseases such as brown rot (Monilinia fructicola) on peaches and other stone fruit and brown rot, gray mold rot (Botrytis cinerea) and bitter rot (Glomerella cingulata) on apples (Pusey et al, U.S. Pat. No. 4,764,371, 1988, and Pusey, U.S. Pat. No. 5,047,239, 1991). Pichia guilliermondii (anamorph Candida guilliermondii) was shown to be effective against a number of pathogens including Botrytis cinerea, Pencillium expansum and Alternaria alternata (Wilson et al., U.S. Pat. No. 5,041,384, 1991). McLaughlin et al. (Phytopathology, 1990) and Wilson et al. (Scientia Horticulturae, 1993) also have shown that various strains of Candida sp. were effective against Botrytis cinerea and Pencillium expansum in apples. A review of biocontrol technology was presented by Wilson and Wisniewski (Ann. Rev. Phytopathol., 1989). In addition to the use of microorganisms, the use of sugars and sugar analogs has also recently been investigated for application as fungicides on agricultural commodities (El -Ghaouth and Wilson, unpublished results). The antifungal property of sugar analogs is well documented; however, few attempts had been made to utilize them as fungicides (Barnett and Lilly, Science, 1951; Atkin et al., Ann Appl. Biol., 1964). The antifungal activity of 2-DG in particular has long been known (Johnson, J. Bacteriology, 1968; Biely et al., J. Bacteriology, 1971; Zonneveld, Developmental Biology, 1973); however, exploitation of this property for the inhibition of postharvest diseases on fruits and vegetables was not attempted.
Although biological control agents have proved safe and effective, the antagonistic effect has often fallen short of that achieved by chemical fungicides. A search for improvements has therefore continued in order to obtain biological control equal to, if not better than, that obtainable by chemical means.
SUMMARY OF THE INVENTION
We have discovered a novel biocontrol composition comprising a strain of the antagonistic microorganism Candida saitoana (C. saitoana) and the sugar analog 2-deoxy-D-glucose (2-DG). The combination gives control superior to that of antagonist alone and comparable to that achieved with synthetic chemical fungicides.
Accordingly, it is an object of the invention to provide a novel biocontrol composition which is an effective inhibitor of postharvest diseases in fruits and vegetables.
It is also an object of the invention to provide a method of treating fruits and vegetables for the control of postharvest diseases by the application of effective amounts of the novel composition.
Other objects and advantages will become readily apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the percent rot of apples treated with 0.5% 2-DG, C. saitoana and the combination of C. saitoana and 0.5% 2-DG. Water served as the control.
FIG. 2 shows the growth of C. saitoana isolate 240 in apple wounds alone and in the presence of 0.5% 2-DG, 1% 2-DG and the combination of 2% CaCl 2 and 1% 2-DG.
All percents are given in wt/vol.
DETAILED DESCRIPTION OF THE INVENTION
Since 2-DG showed effectiveness as an antifungal agent in the control of postharvest diseases (El -Ghaouth and Wilson, supra), the possibility existed that it would be a useful additive to biocontrol compositions utilizing antagonistic microorganism, provided that an effective microorganism which was also resistant to the fungicidal activity of the sugar analog could be found. Isolate 240 of C. saitoana was found to meet those requirements. Although some Candida species were known to be antagonists to postharvest diseases (McLaughlin et al., 1990, Wilson et al., 1993 and Wilson and Wisniewski, 1989, supra), such activity by C. saitoana was previously unknown.
C. saitoana isolate 240 was obtained from the surface of citrus fruit by repeatedly washing the fruit with sterile water. The microorganism was thereafter plated and grown on any nutritionally rich medium sufficient to support the growth of microorganisms. Preferably, the medium was either yeast dextrose agar (NYDA) or yeast malt extract agar (YM).
The isolate was identified as Candida saitoana Nakase & Suzuki based on morphological and physiological characteristics at the German Collection of Microorganisms and Cell cultures, Braunschweig, Germany, and the Centraalbureau voor Schimmelcultures, Delft, the Netherlands.
The isolate had the following morphological characteristics: colonies on malt extract agar were smooth and butyrous with lobate margins; blastospores were 4-7μ and were globose ellipsoidal; no mycelium and pseudomycelium were present; and no sexual reproduction was detected.
Utilization of carbon and nitrogen sources was tested, and the results are shown in Table 1. In addition, no growth was observed at 37° C. or in the presence of 60% glucose.
TABLE 1______________________________________Utilization of C- and N-sources______________________________________Anaerobic:Glucose -Aerobic:Glucose + α-methylglycoside +Galactose + Salicin +Sorbose + Cellobiose +Rhamnose - Maltose +Dulcit - Lactose +Inositol - Melibiose +Mannitol + Sucrose +Sorbitol + Trehalose +Glycerol + Inulin +Erythritol - Melezitose -D-Arabinose - Raffinose +L-Arabinose w Starch -Ribose - Xylitol +D-Xylose + Gluconate -L-Xylose - 2-keto-Gluconate +Adonitol + 5-keto-Gluconate - 1,2 propanediol + Nitrate - Ethylamine -______________________________________ w = weak
Conventional screening procedures were carried out to test the ability of the isolate to grow in the presence of 2-DG. Culture conditions known to be effective for Candida sp. were utilized, with the exception that 2-DG in concentrations in the range of 0.01% to 0.1% was added to the growth medium.
Cultures may be grown under aerobic conditions at any temperature which is effective, i.e. from about 10° C. to about 30° C. The preferred range is from about 20° C. to about 25° C. The pH of the growth medium is about neutral, i.e. pH 6.7 to 7.2. Incubation time is the amount of time required for the microorganisms to reach a stationary growth phase, preferably from about 40 to about 60 hours.
The isolate may be grown in any conventional shake flask for small fermentation runs. Large scale operations, however, may be carried out in a fermentation tank, while applying agitation and aeration to the inoculated liquid medium. Following incubation, microorganisms are harvested by conventional sedimentation means, such as centrifugation or filtering. Cultures may be stored on silica gel and frozen until needed for use.
Samples of the isolate were deposited with the culture collection at the Northern Regional Research Center, U.S. Department of Agriculture, Peoria, Ill. 61604, under the acquisition number NRRL Y-21022 on Dec. 3, 1992. The deposited material was accepted for deposit under the Budapest Treaty on the International Recognition of the Deposit of Microorganisms for the purpose of patent procedures. Further, the depository affords permanence of the deposits and ready accessibility thereto by the public if a patent is granted, and the material has been deposited under conditions that assure that access to the material will be available during the pendency of the patent application to one determined by the Commissioner of Patents and Trademarks to be entitled thereto under 37 CFR 1.14 and 35 USC 122. All restrictions on the availability of the deposited material to the public will be irrevocably removed upon the granting of the patent.
Solutions of 2-DG (Sigma Chemical Co., St. Louis, Mo.) were prepared by dissolving a sufficient amount of the sugar analog in sterile deionized water and membrane filtering.
The novel composition was prepared by adding a sufficient amount of the 2-DG solution to a suspension containing an effective amount of microorganisms. An effective amount is that concentration which inhibits the growth and development of the targeted pathogen when applied to the fruit. An effective concentration may vary, depending on such factors as (1) the type of fruit, (2) the ripeness of the fruit, (3) the estimated concentration and type of pathogens, (4) the type of wound on the fruit and (5) the temperature and humidity. Exemplary concentrations range from about 10 7 to about 10 9 CFU/ml, preferably about 10 7 to about 10 8 CFU/ml. Effective amounts of 2-DG range from about 0.01% (w/v) to about 1.0% (w/v), preferably about 0.05% (w/v) to about 0.1% (w/v).
The composition is preferably applied as a suspension in water, however, the liquid medium in which the microorganism is grown is also suitable. In addition, conventional additives such as surfactants and wetting agents may also be included in the composition in order to enhance its effectiveness.
The composition is useful for the control of postharvest diseases in a variety of fruit including, but not limited to, apples & peaches.
The composition may be applied to fruits utilizing conventional application methods such as dipping, spraying or brushing. In addition, it may also be incorporated into waxes, wraps or other protective coatings used in processing the fruits. Applications may be made at any time before or after harvest, however, treatment preferably occurs after harvest and prior to storage or shipment.
The following example is intended to further illustrate the invention and not to limit the scope of the invention as defined by the claims.
EXAMPLE
The effect of different treatments (0.5% 2-DG, 10 CFU/ml C. saitoana and 0.5% 2-DG+C. saitoana) on the decay of apples inoculated with Botrytris cinerea (B. cinerea) was investigated. Apples were wounded (3 mm×5 mm), and 50 μl of each treatment was placed in each wound (control apple wounds received water). The wounds were allowed to dry 30 min at room temperature. After air drying, the wounds were challenged with 30 μl of a spore suspension of B. cinerea consisting of 10 5 conidia/ml. There were four replicates of 50 fruit per treatment with complete randomization. Lesion diameter and percent infection were determined for each treatment at 7, 10, 14 and 16 days after challenge. The tests were repeated four times, and the data were analyzed by analysis of variance. In order to determine the survival of the yeast in the presence of 2-DG at the wound site, scrapings were made of the wound surface at various times. These scrapings were diluted serially in sterile water, plated on potato dextrose agar, and the yeast growth observed.
The study demonstrated that the combination of 2-DG and C. saitoana was more effective in controlling B. cinerea rot of apple than either 2-DG or C. saitoana alone (FIG. 1). After 16 days of storage at 24° C., less than 20% of the apples treated with the combination of 2-DG and C. saitoana developed infection, while in fruit treated with either 2-DG or C. saitoana alone, more than 95% and 55%, respectively, of the fruit were diseased. A synergistic effect exhibited by the combination of the two components of the composition is therefore strongly suggested.
The inhibitory effect of this combination is further amplified at low temperatures. A complete control of decay was achieved for up to 35 days of storage at 4° C.
The effectiveness of the combination of 2-DG and C. saitoana in controlling decay appears to stem from the interplay of the biological activity of C. saitoana and the antifungal property of 2-DG. Sugar analogs, such as L-sorbose and 2-DG, are known to interfere with the growth of several yeasts and some filamentous fungi when used as a sole carbon source (Atkin et al., 1964; Biely et al., 1971; supra). Their ability to readily form phosphate esters that cannot be further metabolized and that interfere with the metabolic processes implicated in cell wall biosynthesis is believed to be the basis of their antifungal action in yeasts. In the case of 2-DG, its inhibitory activity has been extensively studied in yeasts where it was found to affect cell wall-forming enzymes, namely β-1,3-glucan synthetase (Biely et al., 1971, supra). Very little information is known, however, concerning its effect on phytopathogenic fungi. Thus, the extent of the inhibitory effects exhibited by the combination of the two was quite surprising. Although 2-DG appears to adversely affect the growth of filamentous fungi including postharvest pathogens and some yeasts, it does not affect the growth of C. saitoana isolate 240 (FIG. 2), thereby allowing the exploitation of the inhibitory activity of the sugar analog and the antagonistic activity of the microorganism.
It is understood that the foregoing detailed description is given merely by way of illustration and that modifications and variations may be made therein without departing from the spirit and scope of the invention.
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A biocontrol composition comprising an antagonistic microorganism and a sugar analog (2-deoxy-D-glucose) gives a level of control superior to that of either component when used alone and comparable to that of synthetic chemical fungicides. The antagonistic microorganism is an isolate of Candida saitoana and has resistance to the fungicidal activity of sugars and sugar analogs.
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The present application is a Divisional application of U.S. patent application Ser. No. 10/373,017 filed on Feb. 26, 2003 now U.S. Pat. No. 7,288,234.
STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without payment of any royalties thereon or therefor.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the treatment of hazardous waste and, in particular, to the use of a processing fluid additive for safely and effectively treating water-wet hogout propellant as well as any other water-wet propellants, explosives and hazardous wastes to make them compatible with the MSO (Molten Salt Oxidation) process.
2. Description of the Background
The dynamics of a smelt-water explosion may not be completely understood, but it has long been recognized that it is an event to be avoided. A black smelt explosion is caused by unevaporated water reacting with unburned residue or hot ash at the bottom of the boiler, says Esa Vakkilainen, senior research manager at recovery boiler specialist Andridz-Ahlasperon. For example, a black smelt boiler “explosion” closed Sodra Cell's Norwegian kiaft pulp mill at Tofte in September 2000. This resulted in around 80,000 tons of softwood and eucalyptus pulp being lost from market production, affecting both suppliers and customers.
There have been efforts to prevent smelt explosions in kraft mills as above. This is reflected in U.S. Pat. Nos. 3,447,895 to Nelson et al., 4,106,978 to Nelson, 4,194,124 to Nutley et al., and 4,462,319 to Larsen. These patents suggest solutions in the form of (1) introduction of a liquid to rapidly cool the smelt bed (e.g. Nelson et al.), (2) introduction of a water-absorbing powder (e.g. Nelson, Larsen), and (3) irradiation of the smelt/water interface to create non-explosive nucleate boiling (e.g. Nutley et al.).
As a result of the foregoing efforts, it is known that polyglycols (polyethylene glycol and polypropylene glycol) can help to prevent smelt-water explosions in kraft chemical recovery furnaces. The ability of polyethylene glycol or “PEG” to prevent smelt-water explosions is described in U.S. Pat. No. 3,447,895 Nelson et al. The '895 patent discloses a method of preventing explosions in kraft chemical recovery furnaces due to water leaking into the molten smelt in the furnace. An aqueous quenching solution of polymeric glycol (polyethylene glycol and polypropylene glycol) is introduced into the furnace to rapidly cool the smelt to safe temperatures without itself causing an explosion.
The risk of smelt explosion also arises in the context of MSO waste treatment. The Molten Salt Oxidation (MSO) process is a thermal, flameless process that has the inherent capability of completely destroying organic constituents of mixed wastes (chlorinated solvents, spent ion exchange resin), hazardous wastes (PCB-contaminated oils), and energetic materials. The MSO process is commonly used for treatment of water-wet propellant and explosive wastes that are typically generated when a propellant or an explosive is removed from its casing using a high pressure water jet. One example of this is hogout propellant. However, smelt-water explosions are also able to occur in high-temperature furnaces/reactor vessels during MSO waste treatment.
Thus, the ability of the polymeric glycols in preventing explosions in kraft chemical recovery furnaces would seemingly make them useful for the MSO process. However, the MSO process is quite different from that of a kraft chemical recovery furnace in that it is a chemical reaction process. The reactants, including solid, gas or liquid wastes concurrently with air, are introduced into a reaction medium, which is molten sodium carbonate or a blend of other salts at temperatures ranging from 700-1000 degrees Centigrade. The reaction medium may or may not enter the reaction, however, it serves as a host to generate combustion products and to facilitate or to catalyze the reaction between the oxygen in the incoming air and the combustion products. Therefore, the MSO process imposes a different set of requirements upon the reactants or feed streams than does a kraft chemical recovery furnace.
Consequently, it would be greatly advantageous to reduce/eliminate the potential for smelt-water explosions that are able to occur in high-temperature furnaces/reactor vessels during MSO by a process that employs polymeric glycol to prevent a smelt-water explosion due to the accumulation of dangerous levels of sodium chloride and/or sodium sulfide in the molten sodium carbonate in the MSO reactor vessel. Sodium chloride and sodium sulfide are known to create a highly explosive smelt in kraft chemical recovery furnaces.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a method for reducing/eliminating the potential for smelt-water explosions that are able to occur in high temperature furnaces/reactor vessels during MSO waste treatment by use of a particular polymeric glycol in a particular manner to prevent a smelt-water explosion due to the build up of sodium chloride and/or sodium sulfide in the molten sodium carbonate and the addition of water in the MSO reaction vessel.
It is another object to select a glycol for the process as described above that is uniquely-suited for MSO waste treatment, maximizing the desired combination of properties in the MSO context including water solubility, hygroscopicity, low volatility, thermal stability, good combustibility and clean burnout, low viscosity and lubricity, low toxicity and the ability to partition the energetic material to prevent massing.
According to the present invention, these and other objects are accomplished by a process for using polyethylene glycol (PEG) as a processing fluid additive for safely and effectively treating water-wet hogout propellant as well as any other water-wet propellants, explosives and hazardous wastes to make them compatible with the MSO process. The method includes the step of applying liquid PEG to the hazardous waste to create a slurry that when fed directly into the MSO reactor vessel prevents a smelt-water explosion due to the accumulation of dangerous levels of sodium chloride, and/or sodium sulfide, and water. The PEG possesses special qualities that make it ideal for this purpose. It is a low cost, low viscosity, commercially available, non-hazardous (per OSHA standards), water soluble, low toxicity chemical that burns cleanly leaving little or no residue. It also prevents the propellant residue from sticking back together thus facilitating a uniform feedstock that can be conveyed using a pump.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a method and system for slurrying the water-wet hogout propellant using the PEG as a processing fluid additive.
FIG. 2 illustrates a system for treating the foregoing slurry using the molten salt oxidation “MSO” process.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is a processing fluid and method of using the same for safely and effectively treating water-wet hogout propellant as well as any other water-wet wastes using the MSO process.
Using the water-wet hogout propellant as an example, solid rocket propellant upon expiration of its service life is removed from the rocket motor casing by a high-pressure water jet. The resulting waste, referred to as “hogout propellant”, typically contains a large excess of water. In order to prepare the hogout propellant for treating it using the MSO process the excess water is removed. However, it is not possible to remove 100 percent of the water from the hogout propellant in the dewatering process.
Feeding wastes containing liquid water into the molten carbonate bath used in the MSO process has the potential for a destructive “smelt-water” explosion. “Smelt-water” explosions are not completely understood, but they are known to be physical (i.e. flameless) explosions that result when water is converted supersonically into steam to produce a shock wave. Molten sodium carbonate by itself will not cause an explosion with water, but it will cause an explosion if it contains more than approximately 6 percent sodium chloride or about 12 percent sodium sulfide or a combination of sodium chloride and sodium sulfide. Sodium chloride, in particular, accumulates in the MSO salt bath due to the reaction of the sodium carbonate with the hydrogen chloride produced from the combustion products from the ammonium perchlorate (AP) oxidizer contained in the hogout propellant itself and in the residual water.
Referring to FIG. 1 , there is illustrated a system for MSO waste treatment using PEG to prevent a smelt-water explosion. The system includes an initial treatment station 1 for removing excess water from water-wet hogout to make it compatible with the MSO (Molten Salt Oxidation) process. Treatment station 1 comprises a liquid filter bag 8 fitted into a perforated stainless steel basket 6 , which in turn is fitted into a stainless steel drainage tank 4 . The water-wet hogout propellant 100 is placed into a 5-micron polypropylene liquid filter bag 8 which is fitted into a perforated stainless steel basket 6 , which in turn is fitted into a stainless steel tank 4 . By filtration down through the filter bag 8 and basket 6 , excess water 80 is drained and removed. The dewatered hogout propellant 100 is then removed from the filter bag 8 and is transferred to a grinding vessel 2 for creating a slurry 90 according to the present invention.
As also seen in FIG. 1 , the present invention adds a processing fluid 200 to vessel 2 through an inlet at the front end to prevent a “smelt-water” explosion during treatment of the hogout propellant 100 in the MSO process. The processing fluid 200 is added to vessel 2 for grinding and mixing the water-wet hogout propellant 100 with an agitator 2 a and a homogenizer 2 b to produce a slurry 90 for the MSO process.
The processing fluid 200 , in particular, is polyethylene glycol, or “PEG”. For example, PEG having an average molecular weight range of 380 to 420 (amw) and having the chemical formula, H—(OCH 2 CH 2 )n-OH where n has an average value of 8.7 is suitable for use. The n average value may vary within a range of 4.1 to 13.2 for an average molecular weight range of 190 to 630 without detracting from the efficacy of the invention. PEGs in the molecular weight range from 190 to 630 are ideally suited as a carrier for both homogenizing (size reduction/slurrying) and feeding the ground hogout propellant 90 because they are liquids and have complete solubility with water in all proportions. Water solubility of the PEGs also facilitates the cleanup of equipment or environmental spills. The PEG is provided in liquid form because liquid PEG has a low toxicity. It is not a “Hazardous Chemical” as defined by the OSHA Hazard Communication Standard, 29 CFR 1910.1200. Liquid PEG forms an aqueous solution with water in all proportions.
The amount of liquid PEG 200 admitted to vessel 2 is controlled in accordance with the amount of residual water in the hogout propellant 100 to ensure a minimum concentration of 20 percent by weight PEG in the solution of water and PEG.
Once inside the grinding vessel 2 , the PEG 200 acts as a humectant and tends to absorb water from the water-wet hogout propellant 100 during homogenization. Since water in the propellant makes the propellant difficult to burn, the displacement of the water improves the combustibility of the propellant in the MSO process.
Referring to FIG. 2 , there is illustrated an MSO reaction vessel 12 , and a pumping system for introducing the foregoing slurry 90 from vessel 2 into MSO reaction vessel 12 . After the water-wet hogout propellant 100 has been fully ground with homogenizer 2 b and agitator 2 a and the PEG 200 , the slurry 90 is charged into a 5-gallon stainless steel stockpot 40 . The pumping system transfers the slurry 90 from stockpot 40 into a molten sodium carbonate bath 10 via a downcomer 30 in a reaction vessel 12 having a wall 14 formed of a nickel-chromium alloy such as Inconel 600 or other suitable material, pairs of resistance heaters 16 and alumina-silica insulation 18 . Downcomer 30 may be a conventional downcomer in which the feed is mixed with air.
The pumping system further comprises a positive displacement metering pump 42 which pumps the slurry 90 at a metered flow rate into the molten sodium carbonate bath 10 in the reaction vessel 12 via the downcomer 30 at inlet 20 . When the flow of the slurry 90 to the reaction vessel 12 is shut off, it is recycled to the stockpot 40 via a 3-way valve 44 and return line 46 . Air for atomization and oxidation are admitted respectively into the molten sodium carbonate bath 10 in the reaction vessel 12 at inlets 24 and 22 of the downcomer 30 . Inlet 22 is used for the oxidizing air and inlet 24 is used for the atomizing air. The off-gas including CO 2 , CO, O 2 , NO X formed by the oxidation reaction, and N 2 are discharged at 26 . Since the PEG has a low volatility and is thermally stable to approximately 300 degrees C., the PEG serves to carry the waste material into the molten sodium carbonate bath 10 before vaporizing or decomposing. Moreover, PEGs have lubricity and a low viscosity (depending on molecular weight have a viscosity at 210 degrees F. ranging from 4.3 to 10.8 centistokes). Thus, PEGs provide internal and external lubrication and facilitate the pumping of slurries of wastes in the PEGs using a positive displacement metering pump 10 such as the Seepex pump Model 0015-24 which has been certified for pumping propellants and explosives. Moreover, PEGs are noncorrosive to rubber thus do not cause the rubber binders used in propellants and explosives to swell or become sticky which is important for feeding. PEGs are inherently an anti-sticking agent that promotes homogenization of the hogout propellant for slurrying and pumping. It effectively partitions the slurried material and significantly slows settling in the process lines.
The molten salt bath 10 contained in the bottom of the reaction vessel 12 and into which the slurry waste is introduced can be of any known composition serving as a medium for treatment, and is typically an alkalai metal carbonate such as sodium carbonate, potassium carbonate or lithium carbonate, or mixtures thereof, e.g. a mixture of 50 percent Na 2 CO 3 and 50 percent K 2 CO3, by weight; mixtures of alkali metal carbonate such as sodium carbonate and alkali metal chloride such as sodium chloride, e.g. 10 percent Na 2 CO 3 and 90 percent NaCl, by weight and the like. For example, molten salt consisting of 100 percent molten sodium carbonate is contained in reaction vessel 12 at a temperature of about 900 degrees C.
The temperature of the molten salt bath 10 for carrying out the oxidation of the organic waste generally ranges from 870 degrees C. to 950 degrees C., e.g. ideally about 900 degrees C. and such temperature can be maintained by incorporating the molten salt reaction vessel 12 e.g. within pairs of electric resistance heaters 16 and alumina-silica insulation 18 . A portion of the heat is generated by the oxidation reaction itself.
Sufficient air is fed concurrently with the waste, below the surface of the melt, to provide oxygen to assure complete carbon oxidation to carbon dioxide, which at 20 mole percent excess is 1.2 moles of air for every mole of carbon added. To maximize vessel life, the unit should be maintained at an operating temperature of about 900 degrees C. However, at temperatures exceeding about 950 degrees C. the reaction vessel 12 undergoes a rate of corrosion that greatly exceeds the normal rate of 0.015 inches per 1,000 hours at 950 degrees C. that has been reported. Furthermore, at temperatures exceeding 950 degrees C. the material properties of the nickel-chromium alloy material of the reaction vessel 12 are deteriorated resulting in a significant reduction in the material strength of the reaction vessel 12 .
The PEGs contain oxygen (approximately 39 weight percent) to support the MSO combustion process in the reaction vessel 12 . To provide additional oxygen dry air is injected at a feed rate ranging from 100 to 360 liters per minute concurrently with the waste feed stream via downcomer 30 into the molten salt bath 10 . PEGs due to their chemical composition burn away completely and cleanly leaving virtually no residue (less than 0.05 percent). The low ash content of the PEGs should not contribute to residue buildup in the salt bath. It is desirable to have no buildup of ash in the salt bath from MSO processing.
During the combustion process the organic constituents of the waste materials are oxidized to carbon dioxide, carbon monoxide, oxides of nitrogen, and water. The inorganic products resulting from the reaction of the molten salt with the halogens, sulfur, phosphorous, metals, and radionuclides introduced into the salt bath results in the buildup of the inorganic products in the sodium carbonate. The excess buildup of these products in the carbonate salt can result in a reduction in the efficiency of the system and can generate a highly explosive melt. The carbonate salt serves both as a chemical reagent and as an acid scrubber to neutralize and to retain any acidic by-products produced during the waste destruction process. As the carbonate content in the salt decreases, the efficiency of the process decreases and the carbonate salt must be removed from the reaction vessel 12 via outlet 28 and replaced.
Throughout the homogenizing and treatment processes it is nearly impossible for an operator to avoid contact with the carrier in the processing of the hogout propellant and other wastes that would use the PEGs as a carrier. Nevertheless, in reaction vessel 12 the PEGs pose no health hazards to the user. PEG is not a “Hazardous Chemical” as defined by the OSHA Hazard Communication Standard, 29 CFR 1910.1200. It is therefore essential that the carrier have a low toxicity. Also, the PEGs are not hazardous to the environment.
In light of the foregoing it should be apparent that the PEG processing fluid 200 and method of using the same in the context of the MSO process will prevent a “smelt-water” explosion. However, it should also be apparent that the key properties discussed above make the PEGs suitable for the MSO process because the MSO process is different from that of a kraft chemical recovery furnace and because of this, other properties are required for suitability as an adjuvant for processing of wastes such as the hogout propellant. No other polymers are known that possess this combination of key properties.
Having now fully set forth the preferred embodiments and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that the invention may be practiced otherwise than as specifically set forth in the following claims.
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An improved system and method for using polyethylene glycol (PEG) as a processing fluid additive for safely and effectively treating water-wet hogout propellant as well as any other water-wet propellants, explosives and hazardous wastes (solids and liquids) to make them compatible with the MSO process. The method includes the step of applying liquid PEG to the hazardous waste to create a slurry or feedstock that when fed directly into the MSO reactor vessel prevents the occurrence of smelt-water explosions due to the accumulation of dangerous levels of sodium chloride, and/or sodium sulfide in the molten salt bath. The PEG possesses special qualities that make it ideal for this purpose. It is a low cost, low viscosity, commercially available, non-hazardous (per OSHA standards), water soluble, low toxicity chemical that burns cleanly leaving little or no residue.
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BACKGROUND OF THE INVENTION
[0001] This invention relates to the utilization of nanoparticles in powder coating formulations to enhance various properties of the coatings.
[0002] Conventional powder coatings have many shortcomings in their process and application properties. For example, in order to obtain a good and smooth film, powders must flow well at cure temperature, and many powder coating systems do not flow well due to their high melt viscosity. One normal way to improve the flow is to use resin binders of low melt viscosity. However, low-viscosity resins usually also have low glass transition temperatures, which diminishes storage stability as sintering increases. A typical powder coating formulation must have a softening point higher than 40° C. to prevent sintering and maintain sufficient storage stability.
[0003] Conventional powder coatings also suffer from low surface hardness, as well as abrasion and stain resistance. These shortcomings prevent powder coatings from further penetrating into many applications areas of conventional solvent coatings.
[0004] The use of inorganic fillers to improve properties of coatings is well known. However, there are many limitations in using fillers. First of all, larger quantities of fillers must be used to obtain good results, and this can change other properties of powder coatings. For example, the melt viscosity can be increased dramatically. Secondly, it may be difficult to incorporate large quantities of filler into coating compositions desired by coating performances due to the difficulty of the dispersion process and dispersion stability problems, mainly because of the filler's incompatibility with organic resins and hardeners.
[0005] Nanoparticles discussed in the current invention are inorganic particles with diameters in the range of 1 to 100 nanometers. An inorganic nanoparticle can be, for example, clay-based. A clay particle can be chemically modified to be compatible with organic polymers by inserting or “intercalating” chemistry into the spaces or “galleries” between the clay surfaces. When the clay particles are fully dispersed in the host polymer, a state of “exfoliation” occurs. Due to the large surface area of nanoparticles, even small amounts can have an intimate interaction with the polymer, and change coating properties significantly. Therefore, nanoparticles can enhance many properties of powder coatings.
[0006] In the following reference: S. Sepeur, et al., Mater. Res. Soc. Symp. Proc., Vol., 576, (1999), a sol-gel process was described in which a hybrid of thermoset resin/SiO 2 nanoparticles was produced in situ. A pencil hardness of 4H was achieved. However, this process has the following disadvantages: 1) The synthesis of the resin requires a large portion of organo-silicon compounds, which increases raw material cost; 2) The method is not compatible with current powder coating manufacturers processes; 3) Hydrolytic stability of the coatings is a concern.
[0007] In U.S. Pat. Nos. 5,385,776, 5,514,734 and 5,747,560 nanocomposites employing thermoplastic resins, e.g. polyamides, polyolefins, vinyls, e.g. plasticized PVC, etc., are disclosed as useful in powder coating. However, thermoplastics based powder coating compositions have significant limitations as will now be discussed.
[0008] Disadvantages of Thermoplastic Based Powder Coatings
[0009] Powder coating types can be categorized into two broad divisions: thermoplastic and thermocurable. Thermoplastic powders do not chemically react during application or baking. Therefore, these materials will remelt after cooling when heat is applied. Due to their nature and application limits, thermoplastic powders are generally used only for functional coatings.
[0010] Unlike thermoplastic coatings, thermocurable powder coatings will chemically react during baking to form a polymer network which is more resistant to coating breakdown. Additionally thermocurable powder coatings will not remelt after cooling when heat is applied. Even though there is widespread use of functional powder coatings for protective purposes, the vast majority of powders are utilized in decorative applications where color, gloss, and appearance may be the primary attributes. That is why the powders used in the industry are predominantly thermocurable powder coatings.
[0011] Polyamide is a typical thermoplastic powder coating resin. Examples of the disadvantages of a thermoplastic powder coating system are:
[0012] High cost
[0013] High process temperatures
[0014] High viscosity
[0015] Poor adhesion to most substrates
[0016] a Low thermal stability
[0017] Not easy to achieve thin films
[0018] Process Limit—can only be applied by fluidized bed application equipment.
[0019] Only limited to functional coatings.
SUMMARY OF THE INVENTION
[0020] Due to the nature of powder coatings and the characteristics of nanoparticles, there is great potential in using nanoparticles to enhance various properties of powder coatings. Therefore, the first object of the invention is to provide a composition, which incorporates certain types of nanoparticles for making powder coatings with high pencil hardness, in certain resins, i.e. thermocurable or radiation curable resins such as polyesters, epoxy, acrylics and vinyl functional resins such as vinyl esthers. Such resins and nanoparticles are employed in the other object applications set forth below.
[0021] The second object of the invention is to provide a composition, which incorporates certain types of nanoparticles for making powder coatings with high scratch resistance.
[0022] Another object of the invention is to provide a composition which incorporates a certain type of nanoparticles for making powder coatings of low viscosity and excellent flow-out property, which results in finished films of great smoothness and great distinctiveness of image (DOI).
[0023] Another object of the invention is to provide a composition, which incorporates certain types of nanoparticles for making powder coatings with high abrasion/wear resistance.
[0024] Another object of the invention is to provide a composition, which incorporates certain types of nanoparticles for making powders with high glass transition temperature and thus desirable storage stability.
[0025] Another object of the invention is to provide a composition, which incorporates certain types of nanoparticles for making powder coatings with high solvent/chemical resistance.
[0026] Another object of the invention is to provide a composition, which incorporates certain types of nanoparticles for making powder coatings with high impact resistance.
[0027] Another object of the invention is to provide a composition, which incorporates certain types of nanoparticles for making powder coatings with high barrier properties.
[0028] Another object of the invention is to provide a composition, which incorporates certain types of nanoparticles for making powder coatings with high fire retardancy and heat resistance.
[0029] Another object of the invention is to provide a composition, which incorporates certain types of nanoparticles for making powder coatings with high refractive index, transparency.
[0030] Another object of the invention is to provide a composition, which incorporates certain types of nanoparticles for making powder coatings with high stain resistance.
[0031] Another object of the invention is to provide a composition, which incorporates certain types of nanoparticles for making powder coatings with controllable gloss.
[0032] Another object of the invention is to provide a composition, which incorporates certain types of nanoparticles for making powder coatings with controllable surface tension.
[0033] Another object of the invention is to provide a composition, which incorporates certain types of nanoparticles for making powder coatings with controllable film permeability.
[0034] The powder coating compositions described above may be processed using conventional methods, e.g. premixing and extrusion. Powders may be applied onto various substrates such as metals, medium density fiber (MDF) board and wood, using conventional and unconventional methods. Examples of conventional application methods are electrostatic spray (Corona charging or Tribo charging), fluidized bed and flamespraying. Curing may be achieved by thermal heating, induction coating, infrared heating, ultraviolet (UV) and electron beam (EB) radiation.
[0035] Other objects of the present invention will become apparent to people skilled in the art from the description of the invention that follows and from the disclosed preferred embodiment thereof.
[0036] The present invention enables the aforementioned objects. Indeed, the invention provides compositions containing nanoparticles for powder coatings with improved properties. The nanoparticles used in the present invention may be untreated nanoparticles, nanoparticles with hydrophobic or hydrophilic functional groups on their surfaces, or nanoparticles with non-reactive or reactive groups on their surfaces. The nanoparticles used in this invention may be melt blended into a powder resin or melt extruded into a powder coating formulations.
[0037] The present powder coating systems are either of the thermocurable or radiation curable types.
BRIEF DESCRIPTION OF THE DRAWING
[0038] [0038]FIG. 1 depicts the effect of nanoclay on resin viscosity;
[0039] [0039]FIG. 2 depicts the flow of a composition containing nanoclay vs. one which does not (control).
DETAILED DESCRIPTION
[0040] A typical thermosetting powder coating formulation consists of the following ingredients:
[0041] Resin(s)
[0042] Crosslinker(s)
[0043] Pigments
[0044] Flow Agent
[0045] Degassing Agent
[0046] Curing Catalyst
[0047] Stabilizers
[0048] Other performance-enhancing additives. Typical resins are:
[0049] Polyesters
[0050] Epoxies
[0051] Acrylics
[0052] These resins are formulated with different crosslinkers (curatives or hardeners) for different application needs. The most commonly used crosslinkers are:
[0053] Amines
[0054] Epoxy resins
[0055] Triglycidyl isocyanurate (TGIC)
[0056] Carboxylic acids
[0057] Anhydrides
[0058] Blocked isocyanates
[0059] Melamines
[0060] Glyco-uril
[0061] Hydroxy alkylamide (e.g. Primid)
[0062] Non-blocked isocyanates
[0063] Another type of powder coating is the radiation-curable (e.g. UV and Electron Beam) system, which consists of one or more resins and photo initiators and other necessary ingredients as mentioned in thermosetting coating systems.
[0064] An example of radiation curable powder coating system contains an unsaturated polyester with a molecular weight in the range of 1,000 to 10,000, a photoinitiator and other ingredients typically used in a conventional powder coating formulation. An example of the unsaturated polyester is UCB Uvcoat 1000. Etc. An example of the photoinitiator is Ciba Irgacure 2959 or in combination with Irgacure 819.
[0065] The following summarizes the experimental procedures and the results obtained. It should be noted that the procedures and formulations only serve as examples of the invention. The scope of the invention is not be limited to these examples.
[0066] As a first embodiment of the invention, there are employed untreated, i.e. unfunctionalized inorganic nanoparticles. These typically are metal oxide nanoparticles such as aluminum oxide, titanium oxide, zirconium oxide and iron oxide, as well as aluminosilicates, e.g. nanoclays, which may be modified with various functional groups such as amines, carbonitrides, silicon nitrides, carbon and silica.
[0067] Such inorganic nanoparticles may then be incorporated in polymerized or resins (polymers) such as thermocurable resins, e.g. polyesters (saturated and unsaturated), polyepoxide and polyacrylates or polymethacrylates, in amounts of about 0.1% to 50%, based on the weight of the powder coating composition.
[0068] As a second embodiment of the invention, the above nanoparticles may be treated with reactive or polymerizable functional groups such as epoxy groups, vinyl groups, acrylates and methacrylates, etc.
[0069] Alternatively, the above nanoparticles may be treated with non-reactive functional materials such as hydrocarbons or may be treated by ion exchange.
[0070] Typically, the present compositions are prepared by melt blending or melt extrusion.
[0071] In melt blending, a resin-nanoparticle mixture is stirred at an elevated temperature.
[0072] In melt extrusion, all of the ingredients of a powder formulation including resin, hardener, pigment, catalyst and nanoparticles are admixed and extruded at elevated temperatures.
[0073] Materials
[0074] Nanomer 1.34 TCA, a nanoclay modified by an amine with long aliphatic substitutes, was obtained from Nanocor Corporation.
[0075] Aluminum Oxide C, an unmodified nanoparticle, was obtained from Degussa-Huls.
[0076] Crylcoat 370, an acid functional polyester powder resin produced by UCB Chemicals Corporation. Acid number (AN)=50 mg KOH/g
[0077] Crylcoat 3004, an acid functional polyester powder resin produced by UCB Chemicals Corporation. AN=70 mg KOH/g.
[0078] RX 01387, an epoxy functionalized Al 2O 3 nanoparticle.
[0079] Melt Blending
[0080] 3556 g of Crylcoat 370 was transferred to a 10-liter round-bottom flask. The resin was heated to 200° C. until completely melted. The temperature was maintained at 200° C. while the molten resin was stirred. 53g of Nanomer I.34TCA was added into the flask. The resin and nanoparticle mixture was stirred at 200° C. for one hour before poured into an aluminum pan. The new resin is referred to as NE 2107.
[0081] Melt Extrusion
[0082] All ingredients of a powder formulation including the resin, hardener, pigment, degassing agent, catalyst and the nanoparticle were mixed in a Prism Pilot 3 High-Speed Premixer. Premix speed was 2000 RPM and total mixing time was 4 minutes. The premixed mixture was then extruded in a Prism 16 PC twin screw extruder at approximately 110° C. The extrudate was cooled at 30° C. for 24 hours. The cooled flakes were ground in a Brinkmann high-speed grinder, sieved with a 140-mesh sieve into the final powder. The powder was applied electrostatically onto aluminum, steel or MDF substrates. The panels were baked at temperatures between 160° C. and 200° C. for 20-40 minutes.
[0083] Property Test
[0084] Viscosity was measured on a Brookfield viscometer at different temperatures. The viscosity profile was generated by plotting the viscosity values against temperatures.
[0085] Inclined plate flow (IPF) test was conducted according to the Powder Coating Institute (PCI) Test Procedure #7.
[0086] Distinctness of image (DOI): The procedure is listed in Instruments for Research and Industry Application Data Sheet included with the Model GB 11-DOI Glow Box.
[0087] Pencil Hardness was measured according to ASTM D3363, Pencil Scratch Hardness was measured.
[0088] Scratch resistance was measured according to the description below.
[0089] One common method of assessing the scratch resistance of a coating is to rub 0000 grade steel wool across the coating surface. The following technique uses a standard weight hammer to apply the force between the steel wool and the coating, increasing the reproducibility between operators. Cloth (cheesecloth or felt is ideal) is attached to the curved face of a 32 ounce ball peen hammer. A piece of 0000 steel wool approximately one inch in diameter is placed on the coating surface to be tested. The cloth covered curved face of the hammer is placed directly on the steel wool and, with the handle of the hammer held as close to horizontal as practical and no downward pressure exerted, the hammer drawn back and forth across the coating. The cloth on the hammer face provides a grip between the hammer and steel wool. Consequently, the steel wool is rubbed across the coating surface with equal force along a path. The path length is typically several inches and each back and forth motion is counted as a cycle. Care is taken to secure the coated substrate firmly and to maintain the same path for each cycle. After a predetermined number of cycles are completed, the coating surface is examined for changes in appearance such as an increase in haze resulting from scratches in the surface. A number, usually 1 to 5, is then given to rank the scratch resistance, 1 has the lowest resistance and 5 the highest. Alternately, cycles are continued and counted until the first visible sign of a change in the appearance of the coating.
[0090] Results and Discussion
[0091] 1. Flow Improvement
[0092] Flow improvement was confirmed by the following three facts:
[0093] 1) The powder resin containing nanoclay had lower melt viscosity. The viscosity profiles of resin Crylcoat 370 (control) and NE 2107 (containing 1.5% nanoclay) were shown in FIG. 1. As can be seen, on average the viscosity of NE 2107 is 30-40% lower that of Crylcoat 370.
[0094] 2) The powder based on NE 2107 had a much longer IPF. As can be seen in Figure 2 and Table 1, the IPF of NE 2107-based powder was 175 mm whereas Crylcoat based powder had an IPF of only 95 mm.
[0095] 3) NE 2107 also exhibits better DOI than Crylcoat 370, as shown in Table 2.
[0096] 1. Hardness Improvement
[0097] Formulations 1 through 5 are listed in Table 1. Coating properties of those formulations including hardness and scratch resistance can be found in Table 2. Comparing entry No. 3 with No. 1, it can be seen that the addition of 5% aluminum oxide C increased the pencil hardness of the coating from F to 3H and scratch resistance from 1 to 2. Similar improvement in hardness was observed with RX-01387 comparing the data of No. 4 and No. 5 in Table 2.
TABLE 1 Formulation of Powder Coatings De- Resin Hardener Nanoparticle Flow- gassing Pigment No. Wt % wt % wt % agent agent (TiO2) 1 CC 370 EPON 2002 — 41.2 27.4 — 1.0 0.4 30.0 2 NE 2107 EPON 2002 *Nanomer I.34TCA 41.2 27.4 0.6 1.0 0.4 30.0 3 CC 370 EPON 2002 Al 2 O 3 C 41.2 27.4 5.0 1.0 0.4 25.0 4 CC 3004 EPON 2002 — 34.3 34.3 — 1.0 0.4 30.0 5 CC 3004 EPON 2002 RX-01387 35.7 32.9 5.0 1.0 0.4 25.0
[0098] [0098] TABLE 2 Properties of the Powder Coatings Formulation Gel Plate Flow Scratch No. (mm) DOI Pencil Hardness Resistance 1 95 80 F 1 2 175 90 H 1 3 — — 3 H 2 4 — — HB 1 5 — — 2 H 1
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A powder coating composition comprising inorganic nanoparticles and a thermocurable or radiation curable resin. The nanoparticles impart a wide range of improved properties to the compositions such as hardness and abrasion resistance.
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BACKGROUND OF THE INVENTION
Field of the Invention
This invention relates to an improvement in a device for detecting an end-shape of a steel tube.
As this kind of the detecting device, there has been known one as shown in FIGS. 1 and 2 of the accompanying drawings. In these figures of the drawings, a reference numeral 1 denotes one of a plurality of detectors arranged around the circumference of the steel tube as an object of detection; a numeral 2 refers to a stand, on which the detectors 1 are to be mounted; a numeral 3 refers to a steel tube; and 4 denotes a pair of pinch rollers.
In such conventional end-shape detecting device for a steel tube, when the distal end of the steel tube 3 which has been carried forward in the direction on an arrow mark by means of the pinch rollers 4 enters the stand 2 having the detectors 1 mounted thereon, the end-shape of the steel tube is detected by the detectors 1, while the steel tube 3 is being carried forward. Thereafter, the end-shape of the steel tube 3 at the rear end thereof is detected in the same manner as mentioned.
In view of the conventional end-shape detecting device of the steel tube being in such a construction as mentioned above, there have existed with the device various disadvantages such that a large number of detectors 1 need to be provided around the circumference of the steel tube 3, that the number of the detectors 1 also needs to be changed depending on variations in the diameter of the steel tube, and further that the outer circumferential surface of the steel tube between the adjacent detectors of a certain established pitch cannot be detected, because the steel tube 3 and the detectors 1 do not revolve in any manner; and various other shortcomings.
SUMMARY OF THE INVENTION
The present invention has been made with a view to eliminating these disadvantages inherent in the conventional detecting device, and aims at providing such end-shape detecting device for a steel tube which is capable of eliminating a non-examined portion on the circumferential surface of the steel tube in its axial direction by making a fitting plate, on which the detectors are mounted, to be rotatable, and adjusting to changes in the diameter of the steel tube by providing a mechanism for changing the positions of the detectors.
According to the present invention, in general aspects of it, there is provided a device for detecting an end-shape of a steel tube which comprises in combination: a plurality of detectors disposed around the circumference of a steel tube to be carried forward by a forwarding means such as pinch rollers; and a detector position changing mechanism provided on each of said detectors to cause the same to move back and forth in the diametrical direction of the steel tube, said detector position changing mechanism being made rotatable around said steel tube.
The foregoing object, other objects as well as specific construction and operations of the end-shape detector for the steel tube according to the present invention will become more apparent and understandable from the following detailed description thereof when read in conjunction with the accompanying drawing, in which:
BRIEF DESCRIPTION OF THE DRAWING
FIGS. 1 and 2 illustrate a conventional device for detecting an end-shape of a steel tube, wherein FIG. 1 is a side elevational view, partly in cross-section, of the detector, and FIG. 2 is a front view thereof;
FIGS. 3 and 4 illustrate one preferred embodiment of the end-shape detecting device for steel tube according to the present invention, in which FIG. 3 is a side elevational view, partly in longitudinal cross-section, and FIG. 4 is a front view thereof; and
FIGS. 5 and 6 are respectively a front view and a cross sectional view taken along the line IV--IV, showing details of the rotary type detecting mechanism according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following discussion, the present invention will be described in detail with reference to one preferred embodiment thereof as illustrated in the accompanying drawing.
Referring to FIGS. 3 and 4 which illustrate the structure of the end-shape detecting device for steel tube according to the present invention, a reference numeral 1 designates four units of detectors which are disposed around the circumference of the steel tube at equally quartered positions therealong. Each detector is supported at the lowest end of a supporting rod 8 for it. A numeral 5 refers to a detector position changing mechanism which is constructed with supporting members 18, each slidably holding the supporting rod 8 thereon, an annular body 11 which rotates with the supporting members 18 being held on it, a rack 10 and a pinion 9 meshed each with other to rotate the annular body 11. A reference numeral 6 denotes a rotatory cylinder which is integrally constructed with the above-mentioned detector position changing mechanism 5, the mechanism being rotationally supported on a machine frame 15 by means of a bearing 14, and being rotated by an electric motor 16 through a pulley 17. A numeral 7 refers to a signal sending and receiving mechanism to perform exchange of signals between the detectors 1 and fixed parts. A numeral 12 refers to a slant groove formed on the surface of a flange which is provided on the rotatory cylinder 6 to the side of the above-mentioned detectors. A numeral 13 refers to a pin of the above-mentioned supporting rod 8, which is to be fitted into the slant groove 12. A numeral 3 refers to a steel tube; 4 denotes pinch rollers; and 19 a guide plate for the annular body 11.
The operations of the end-shape detector for steel tube according to the present invention will now be described hereinbelow. When the steel tube 3 is carried forward in an arrow direction by means of the pinch rollers, the rotatory cylinder 6 is rotated by the electric motor 16 around the steel tube 3 through the pulley 17, whereby the end-shape of the steel tube 3 can be detected through the detectors 1 mounted on the distal end of the supporting rod 8 in the detector position changing mechanism 5. Further, when the diameter of the steel tube 3 is changed, the pinion 9 in this detector position changing mechanism 5 is rotated. Since this pinion is pivotally supported on the flanged surface of the rotatory cylinder 6, it causes the annular body 11 to rotate through the rack 10, and to move up and down the supporting rod 8 to be engaged with the slant groove 12 through its pin 13, thereby changing the positions of the detectors 1 to meet the change in the size of the steel tube to be detected.
Referring now to FIGS. 5 and 6, the operating steps of the detector position changing mechanism 5 will be described in further detail, as follows.
When a handle 20 is rotated by hand, the pinion 9 causes the rack 10 to rotate and the annular body 11 is rotated thereby. Since there are disposed, on this annular body 11, the supporting rod 8 with the pin 13 being fitted thereon and the detector 1 mounted on the distal end position of the supporting rod 8, the movement of the pin 13 follows the locus of the slant groove 12 by the rotation of the annular body 11 with the result that the supporting rod 8 performs its rotation simultaneously with its up-and-down sliding motion. Since this slant groove 12 is of a curvature to enable the supporting rod to move up and down proportionately in correspondence to the diameter of the steel tube 3, graduations on a dial plate can be inscribed with an equal pitch.
It is to be noted that each of the detectors moves at the same time, and a gap between the detectors and the steel tube can be equally adjusted and maintained.
As mentioned in the foregoing, the detectors 1 scan the surface of the steel tube 3 in a spiral form owing to the straight forwarding of the steel tube 3 and simultaneous rotation of the detectors 1, whereby the occurrence of any non-examined portion on the circumferential surface of the steel tube in its axial direction can be perfectly eliminated.
Incidentally, the signal sending and receiving mechanism 7 for the detectors may be constructed by use of a slip ring or a non-contact type rotatory transformer, for example.
As stated in the foregoing, the end-shape detector according to the present invention is of such a construction that the detectors are caused to rotate on the circumferential surface of the steel tube, which contributes to reduction in the number of the detectors, makes it possible to perfectly eliminate the non-examined portion on the surface of the steel tube in its axial direction, and further enables the positions of the detectors to readily correspond to variations in the diameter of the steel tube by provision of the detector position changing mechanism.
Although, in the foregoing, the present invention has been described in specific details with reference to a preferred embodiment thereof, it should be understood that the embodiment is merely illustrative and not so limitative, and that any changes and modifications may be made by those persons skilled in the art within the spirit and scope of the present invention as set forth in the appended claims.
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A device for detecting an end-shape of a steel tube which includes in combination: a plurality of detectors disposed around the circumference of a steel tube to be carried forward by a forwarding mechanism; and a detector position changing mechanism provided on each of the detectors to cause the same to move back and forth in the diametrical direction of the steel tube, the detector position changing mechanism being rotatable around the steel tube.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 14/117,586, filed on Nov. 13, 2013, which is a U.S. National Stage Application under 35 U.S.C. §371 of International Application No. PCT/AU2012/000515, filed on May 11, 2012, which claims priority to Australian Provisional Patent Application No. AU2011901828 filed May 13, 2011 and Australian Provisional Patent Application No. AU2011901829 filed May 13, 2011, all of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to application of a neural stimulus, and in particular relates to applying a neural stimulus in a controlled manner by using one or more electrodes implanted proximal to the neural pathway.
BACKGROUND OF THE INVENTION
[0003] There are a range of situations in which it is desirable to apply neural stimuli in order to give rise to a compound action potential (CAP). For example, neuromodulation is used to treat a variety of disorders including chronic pain, Parkinson's disease, and migraine. A neuromodulation system applies an electrical pulse to tissue in order to generate a therapeutic effect. When used to relieve chronic pain, the electrical pulse is applied to the dorsal column (DC) of the spinal cord. Such a system typically comprises an implanted electrical pulse generator, and a power source such as a battery that may be rechargeable by transcutaneous inductive transfer. An electrode array is connected to the pulse generator, and is positioned in the dorsal epidural space above the dorsal column. An electrical pulse applied to the dorsal column by an electrode causes the depolarisation of neurons, and generation of propagating action potentials. The fibres being stimulated in this way inhibit the transmission of pain from that segment in the spinal cord to the brain. To sustain the pain relief effects, stimuli are applied substantially continuously, for example at 100 Hz.
[0004] While the clinical effect of spinal cord stimulation (SCS) is well established, the precise mechanisms involved are poorly understood. The DC is the target of the electrical stimulation, as it contains the afferent Aβ fibres of interest. Aβ fibres mediate sensations of touch, vibration and pressure from the skin, and are thickly myelinated mechanoreceptors that respond to non-noxious stimuli. The prevailing view is that SCS stimulates only a small number of Aβ fibres in the DC. The pain relief mechanisms of SCS are thought to include evoked antidromic activity of Aβ fibres having an inhibitory effect, and evoked orthodromic activity of Aβ fibres playing a role in pain suppression. It is also thought that SCS recruits Aβ nerve fibres primarily in the DC, with antidromic propagation of the evoked response from the DC into the dorsal horn thought to synapse to wide dynamic range neurons in an inhibitory manner.
[0005] Neuromodulation may also be used to stimulate efferent fibres, for example to induce motor functions. In general, the electrical stimulus generated in a neuromodulation system triggers a neural action potential which then has either an inhibitory or excitatory effect. Inhibitory effects can be used to modulate an undesired process such as the transmission of pain, or to cause a desired effect such as the contraction of a muscle.
[0006] The action potentials generated among a large number of fibres sum to form a compound action potential (CAP). The CAP is the sum of responses from a large number of single fibre action potentials. The CAP recorded is the result of a large number of different fibres depolarising. The propagation velocity is determined largely by the fibre diameter and for large myelinated fibres as found in the dorsal root entry zone (DREZ) and nearby dorsal column the velocity can be over 60 ms −1 . The CAP generated from the firing of a group of similar fibres is measured as a positive peak potential P 1 , then a negative peak N 1 , followed by a second positive peak P 2 . This is caused by the region of activation passing the recording electrode as the action potentials propagate along the individual fibres. An observed CAP signal will typically have a maximum amplitude in the range of microvolts, whereas a stimulus applied to evoke the CAP is typically several volts.
[0007] For effective and comfortable operation, it is necessary to maintain stimuli amplitude or delivered charge above a recruitment threshold, below which a stimulus will fail to recruit any neural response. It is also necessary to apply stimuli which are below a comfort threshold, above which uncomfortable or painful percepts arise due to increasing recruitment of Ai fibres which are thinly myelinated sensory nerve fibres associated with acute pain, cold and pressure sensation. In almost all neuromodulation applications, a single class of fibre response is desired, but the stimulus waveforms employed can recruit other classes of fibres which cause unwanted side effects, such as muscle contraction if motor fibres are recruited. The task of maintaining appropriate neural recruitment is made more difficult by electrode migration and/or postural changes of the implant recipient, either of which can significantly alter the neural recruitment arising from a given stimulus, depending on whether the stimulus is applied before or after the change in electrode position or user posture. Postural changes alone can cause a comfortable and effective stimulus regime to become either ineffectual or painful.
[0008] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.
[0009] Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
SUMMARY OF THE INVENTION
[0010] According to a first aspect the present invention provides a method of applying a neural stimulus with an implanted electrode array, the method comprising:
using the electrode array to applying a sequence of stimuli configured to yield a therapeutic effect while suppressing psychophysical side effects, the stimuli sequence configured such that a first stimulus recruits a portion of the fibre population, and a second stimulus is delivered within the refractory period following the first stimulus and the second stimulus being configured to recruit a further portion of the fibre population.
[0012] According to a second aspect the present invention provides a device for applying a neural stimulus, the device comprising:
at least one electrode configured to be positioned alongside a neural pathway; and a control unit configured to apply a sequence of neural stimuli which are configured to yield a therapeutic effect while suppressing psychophysical side effects, the stimuli sequence configured such that a first stimulus recruits a portion of the fibre population, and a second stimulus is delivered within the refractory period following the first stimulus and the second stimulus being configured to recruit a further portion of the fibre population.
[0015] By providing for a second stimulus to be delivered in the neural refractory period following the first stimulus, the present invention provides for de-correlated, or less correlated, fibre responses to be evoked by such stimuli.
[0016] The sequence of neural stimuli may comprise more than two stimuli, each being delivered in the refractory period following a previous stimulus in the sequence.
[0017] The sequence of neural stimuli may comprise stimuli of ascending amplitude.
[0018] The sequence of neural stimuli may be applied sequentially by a single electrode.
[0019] Alternatively, the sequence of neural stimuli may be applied sequentially by more than one electrode. In such embodiments, the second stimulus is preferably delivered at a time after the first stimulus which allows for cessation of the first stimulus and allows for propagation of a first neural response evoked by the first stimulus from the first electrode to the second electrode, so that the second stimulus is delivered during a refractory period of neurons proximal to the second electrode after activation of those neurons by the evoked neural response from the first stimulus.
[0020] Additionally or alternatively, in some embodiments the sequence of neural stimuli may be applied by consecutive electrodes positioned along an electrode array.
[0021] In embodiments where the sequence of neural stimuli is applied sequentially by more than one electrode, the timing of the respective stimuli in the sequence may be controlled in order to cause spatiotemporal alignment of the respective evoked responses propagating in a first direction along the nerve fibre to thereby cause correlation and summation of evoked responses in the first direction, while causing spatiotemporal misalignment of the respective evoked responses propagating in a second direction opposite the first direction along the nerve fibre, to thereby decorrelate evoked responses propagating in the second direction. Such embodiments may be advantageous in decorrelating evoked potentials propagating toward the brain, where it is desired to avoid or minimise any percept from the stimuli.
[0022] In some embodiments of the invention, the sequence of neural stimuli may be followed by a single stimulus which is not applied during the refractory period of any preceding stimulus, and which is not closely followed by any subsequent stimulus in the refractory period of the single stimulus. Such embodiments may be applied in order to enable an evoked response measurement to be made following the single stimulus, to enable ongoing refinement of stimulus parameters of the sequence of neural stimuli.
[0023] According to another aspect the present invention provides a computer program product comprising computer program code means to make a computer execute a procedure for applying a neural stimulus with an implanted electrode array, the computer program product comprising computer program code means for carrying out the method of the first aspect.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] An example of the invention will now be described with reference to the accompanying drawings, in which:
[0025] FIG. 1 illustrates an implantable device suitable for implementing the present invention;
[0026] FIG. 2 a shows the Aβ response amplitude growth functions for stimulation of the sheep spinal cord at 40, 80 and 120 μs, while FIG. 2 b shows the compound action potential recorded at equivalent charges for the three different pulse widths;
[0027] FIG. 3 illustrates summation of a sequence of overlapped neural responses;
[0028] FIG. 4 is a schematic illustration of a potential pulse sequence and the amplitude growth curve associated with the sequence;
[0029] FIG. 5 illustrates ERT responses to bursts of stimulation with differing frequencies;
[0030] FIG. 6 illustrates a stimuli scheme to generate stimuli which result in synchronising Aβ activation in the antidromic direction and a desynchronising activity in the orthodromic direction:
[0031] FIG. 7 illustrates experimental results obtained by applying a series of four stimuli of ascending amplitude on four adjacent electrodes to a sheep spinal cord;
[0032] FIG. 8 illustrates experimental results obtained in response to stimuli bursts of different inter-stimulus intervals; and
[0033] FIG. 9 illustrates a suitable feedback controller for controlling the parameters of the stimuli burst in an automated manner.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] FIG. 1 illustrates an implantable device 100 suitable for implementing the present invention. Device 100 comprises an implanted control unit 110 , which controls application of a sequence of neural stimuli in accordance with the present invention. In this embodiment the unit 110 is also configured to control a measurement process for obtaining a measurement of a neural response evoked by a single stimulus delivered by one or more of the electrodes 122 . Device 100 further comprises an electrode array 120 consisting of a three by eight array of electrodes 122 , each of which may be selectively used as either the stimulus electrode or sense electrode, or both.
[0035] The activation and simultaneous suppression of different areas of tissue is highly desired for treatment of a number of neurological disorders. The activation of micturition or defection without contraction of the sphincter is highly desirable for treatment of incontinence. The goal of stimulation of the spinal cord is to block transmission of pain signals from Aδ and C fibres, via the inhibitory effect of the activation of Aβ fibres. The ascending Aβ fibres produce a psycho-physiological response which results in the paraesthesia (described as tingling by recipients). A number of ways to reduce or eliminate this effect have been suggested. It has been reported that burst mode stimulation or continuous stimulation at high frequencies can produce pain relief without accompanying paraesthesia, however the mechanisms are not clear.
[0036] One possible explanation is that the high frequency stimulation results in a highly uncorrelated neural firing pattern in the ascending Aβ tracts. High frequency stimulation results in the continuous activation of the fibres and produces a randomised firing pattern. The recovery time (refractory period) between each fibre is slightly different and if a depolarisation potential is present as the fibre comes out of refractory period, it will depolarise again, but not synchronised with other fibres which may still be in their refractory periods. The net result is a randomisation of the firing pattern and a return of the stochastic response in the fibre.
[0037] Measurements of the evoked neural response provide a direct measure of the degree of correlation of the firing pattern. FIG. 2 a shows the Aβ response amplitude growth functions with respect to stimulus amplitude, for stimulation of the sheep spinal cord at 40, 80 and 120 μs. The recruitment is related to charge and so stimulation at 1 mA for 120 μs produces an equivalent charge for stimulation at 3 mA for 40 μs, with vertical lines highlighting two respective points of equal charge delivery for each trace. FIG. 2 b shows the compound action potential recorded at equivalent charges for the three different pulse widths. The peak height is smaller and the evoked response peak is wider at the equivalent charge for the longer pulse width than for the shorter pulse width, and this is indicative of a less correlated evoked response.
[0038] The probability of any single fibre responding is a function of the properties and history of the fibre and the amplitude of the current pulse. Although short and long pulses for an equivalent charge may recruit the same number of fibres the longer lower current amplitude pulse will recruit the fibres over a longer time scale than the higher current shorter pulse width.
[0039] Patients report a preference for stimulation with longer pulse widths and the reason for this preference may be because the perceptual side effect is lower, because there is a lower correlation between the fibres firing. Given this observation, highly uncorrelated responses may give rise to much lower psycho-physical side effects such as tingling sensations and paraesthesia. The evoked responses measured for the longer pulse widths are broader in FIG. 2 b , indicating less correlation in the firing pattern.
[0040] Measurement of the evoked response provides a unique way to assess the degree of correlation amongst fibres in a group, as the peak width and amplitude of the measured response directly relates to the degree of timing synchronisation of the single fibre action potentials which sum to form the compound action potential. The goal of stimulus design is to achieve a high level of recruitment at the segmental level and a low level of correlation for the ascending segments. The neural response measurement obtained at each sense electrode may be conducted in accordance with the techniques set out in Daly (2007/0225767), the content of which is incorporated herein by reference. Additionally or alternatively, the neural response measurement may be conducted in accordance with the techniques set out in Nygard (U.S. Pat. No. 5,785,651), the content of which is incorporated herein by reference. Additionally or alliteratively, the neural response measurement may be conducted in accordance with the techniques set out in the Australian provisional patent application filed simultaneously herewith in the name of National ICT Australia Ltd entitled “Method and apparatus for measurement of neural response”.
[0041] The degree of correlation within an evoked response can be measured with such techniques, and pulse sequences can be designed to produce evoked responses of a desired character. A typical recruitment curve is shown in FIG. 2 a . The strength of the Aβ potentials directly relates to the number of fibres recruited, and therefore stimulation at successive larger and larger pulse amplitudes will recruit successively more fibres. If the pulses are timed so that they occur within the refractory period of the excited neurons from the previous pulse then different sub populations of neurons can be selected with each pulse.
[0042] The timing of each pulse can be so arranged so that the travelling CAPs from each individual pulse cancel each other as they sum at some distance from the stimulation site. This indicates the degree of desynchronisation between the fibres, and as the sensory input is based on correlation of firing patterns the sensation (paraesthesia) is reduced. However, the activation of the inhibitory effect of the Aβ fibres at the segmental level is not reduced, permitting Aβ inhibition of Ai and C propagation to occur, as desired.
[0043] FIG. 3 illustrates the principle of applying a sequence of neural stimuli and allowing the respective evoked responses 302 , 304 , 306 to propagate along the fibre. The numerical summation of five such partially overlapping compound action potentials, of which only three appear in FIG. 3 , is shown at 308 . FIG. 3 shows the effect of the summation of the evoked response from five pulses with the timing intervals between the pulses so arranged as result in the arrival of the evoked response waveform at a designated point along the electrode array such that the averaged signal recorded at that point is minimised. For the data shown in FIG. 3 the timing difference between each cathodic pulse is 0.3 ms.
[0044] FIG. 4 is a schematic illustration of a potential pulse sequence (lower) and the amplitude growth curve associated with the sequence (upper). Current levels A-C are represented on both portions of FIG. 4 . The initial pulse of amplitude A can be expected to recruit only a portion of the available population. Application of the subsequent stimulus of greater amplitude can then be expected to recruit a further portion, but not all, of the available neural population, even though stimulus B is applied during the refractory period after stimulus A. Similarly, stimulus C can be expected to recruit a further portion of the available neural population. C may be applied during the refractory period of stimulus B only, or possibly within the refractory period of both stimuli A and B. The sequence of neural stimuli A-B-C can thus be expected to recruit perhaps a similar amount of the available neural population as would stimulus C if applied alone, however the progressive recruitment of portions of the neural population at progressive times provides for a significantly decorrelated evoked response as compared to the response resulting from a single stimulus of amplitude C.
[0045] The concept of a selection of stimulus sequences based on the ERT recorded parameters can be greatly extended. For instance the example of FIG. 4 demonstrates achieving an uncorrelated ensemble response in the fibre population being stimulated.
[0046] FIG. 5 illustrates ERT responses to bursts of stimulation with differing frequencies. The degree of correlation can be inferred from the ERT signal. A normal stimulus can be used to assess the stimulation response amplitude in the absence of any further desynchronising pulses. The amplitude of the single probe pulse is adjusted to represent the total charge delivered over time for the corresponding desynchronising pulse train. The amplitude of the response measured from the single probe pulse represents a fully synchronised response. The desynchronising pulse train is then output and the response measured. The ratio of the two responses is proportional to the level of synchronisation and so can be used as a control parameter for adjusting the characteristics of the device. For instance the control parameter may be adjustable by the patient to allow the patient to adjust the level of perceived paraesthesia. The control variable may also be used by the system for detection of a change of state in the neural tissue for a diagnostic purpose.
[0047] A single non-decorrelating stimulus can be applied to the nerve by the device periodically or occasionally in order to elicit an evoked response which is then used as the input to the control loop. This probe stimulus can be adjusted so that its charge is equivalent to the charge presented by the desynchronising stimuli. The frequency of the probe pulse to desynchronising pulses can then be adjusted to minimise the perceptual side effects. The probe frequency can also be adjusted on demand, responding more rapidly to changes in movement, for example.
[0048] Conduction of the compound action potentials occurs both orthodromically (up the spine) and antidromically (down the spine). Careful choice of stimulus design can be used to create a situation where the degree of synchronisation can be different in both directions, and controllably so. For example it may be desirable to generate stimuli which result in synchronising Aβ activation in the antidromic direction and a desynchronising activity in the orthodromic direction. One possible scheme for doing this is illustrated in FIG. 6 . A stimulus pulse, preferably biphasic, is discharged at an electrode (electrode ‘0’ indicated on the left side of FIG. 6 ). At some time interval later a 2 nd stimulus pulse is discharged between another two electrodes. For convenience this is illustrated in FIG. 6 as the electrode (number “1”) adjacent to the first electrode. The 2 nd discharge is arranged so that it occurs in time and place such that its resultant CAP propagation to an electrode (e.g. ‘+6’) in one direction (the upward direction in FIG. 6 ) sums with each other evoked CAP. In contrast, in the other direction (the downward direction in FIG. 6 ), the respective CAPs are misaligned and decorrelated for example when observed at electrode ‘−3’.
[0049] A possible means but not the only means to achieve such directional selectivity of CAP correlation is to arrange a series of stimulus pulses with an interpulse interval equal to the difference in propagation time required for desynchronisation of the CAP in the ascending direction.
[0050] Note that the order in which the stimuli are presented does not need to be sequential. The amplitudes of the individual stimuli can also be varied according to the scheme of FIG. 4 . The timing of presentation can also be dithered to adjust the timing.
[0051] FIG. 7 illustrates experimental results obtained by applying a series of four stimuli of ascending amplitude on four adjacent electrodes to a sheep spinal cord. Each stimulus was a tripolar stimulus for which the respective centre electrode was, in order, electrode E 7 , E 8 , E 9 and E 10 , being the four centrally positioned electrodes of a 16 electrode linear electrode array. Each stimulus was biphasic with each phase having a pulse width of 20 μs, and the interphase gap being 10 μs. The stimuli were of ascending amplitude, being 2 mA, 2.5 mA, 3 mA and 3.5 mA respectively. The inter-stimulus interval between each successive pair of stimuli on the respective electrodes was 33 μs, so that the pulse-to-pulse time was 83 μs, to optimally correlate the net evoked response in the antidromic (ie caudal) direction. As can be seen in FIG. 7 the antidromic response 704 measured on electrode E 16 was well correlated from the four constituent parts, and is of large amplitude. In contrast, the four orthodromic responses were effectively decorrelated and produced a net response 702 measured at electrode E 3 which was of much reduced amplitude compared to response 704 travelling in the opposite direction, even though both were produced by the same burst of four stimuli.
[0052] FIG. 8 shows the responses measured at different inter-stimulus intervals. As can be seen the inter-stimulus interval strongly affects efficacy of this technique, and so preferred embodiments provide a feedback loop in order to optimize this parameter, and all other stimulus parameters, in setting up the stimuli burst. FIG. 9 illustrates a suitable feedback controller for controlling the parameters of the stimuli burst in an automated manner, so as to use the measured evoked responses in each direction to determine the stimulus parameters required to achieve a desired directional effect. Such automated feedback permits the relatively large parameter space to be efficiently explored to identify optimal stimuli burst parameters.
[0053] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.
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A method of applying a neural stimulus with an implanted electrode array involves applying a sequence of stimuli configured to yield a therapeutic effect while suppressing psychophysical side effects. The stimuli sequence is configured such that a first stimulus recruits a portion of the fibre population, and a second stimulus is delivered within the refractory period following the first stimulus and the second stimulus being configured to recruit a further portion of the fibre population. Using an electrode array and suitable relative timing of the stimuli, ascending or descending volleys of evoked responses can be selectively synchronised or desynchronised to give directional control over responses evoked.
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FIELD OF THE INVENTION
This invention relates to multi-closure assemblies and particularly to those which may be used for windows, doors, patio doors, French doors, and entry doors or the like and finds particular application in patio doors, casement windows and specifically in a frame including multi-closure members such as individually pivoting casement style members which engage when fully closed, namely all closure members are closed, and provide a continuous shared plane, and when in the fully pivoted open position provide maximum opening from jamb to jamb for entry and exit from the dwelling.
BACKGROUND OF THE INVENTION
Generally in the window and door industry windows are considered to provide the main function of letting in light to a building. Of late it is desirable to have large windows within the building which improve the room lighting but which do not support structural loads. It is therefore a primary object of the invention to provide a preferably load bearing structural closure for installation within a building which includes a multiplicity of closures (and preferably casement style) to provide an enhanced shared plane assembly. Further and other objects of the invention will become apparent to one skilled in the art by considering the following summary of the invention and the more detailed description of the preferred embodiments illustrated herein.
SUMMARY OF THE INVENTION
According to one aspect of the invention there is provided a closure assembly comprising at least two closures moveable in a closure frame, said closure frame including a header, sill and including a track sized to extend the full-length of the header and sill from jamb to jamb thereby providing for guided movement of each individual closure to the maximum extent to and from a fully closed position, the at least two closures presenting a straight line or shared plane, in-line, closure, such as a window, entry door, French door, or patio door assembly and when the closures are pivoted from a closed position whereat said closures are parallel to the extension of said closure frame to a second position wherein the free end of the closure is pivoted away from the closure frame, the free end of said closures have an inter-engaging member which inter-engages with adjacent members to brace together said closures thereby against any loading such as wind loads or the like.
This invention takes advantage of prior known inventions also invented by the present inventor including the teachings of U.S. Pat. No. 5,687,506 and specifically FIGS. 1B, 2, and 3 there in. The teachings in relation to the construction of the pivoting shaft, pivot shoes, the rack, pinion and pivot shoe and the inter-engagement thereof are hereby incorporated by reference in their entirety as if they were written into this application. Further the teachings of U.S. Pat. No. 6,405,781 are also hereby incorporated by reference with respect to the teachings of screens contained within a pocket in the jamb of a closure assembly and the pocket being disposed in a jamb section and of a particular shape compatible with the shape of the pivot bracket as best seen in FIG. 48 of that patent.
Specifically referring to the closure assembly construction in the preferred embodiments, each consists of a frame including a header, sill, and two jambs, each header and sill including racks within each track and sized to fit the full-length of the header and sill in parallel fashion as per the teachings of the herein mentioned patents. The sashes in these frames are built on the same concept. Each casement as illustrated in the figures can include a bubble seal all around for exceptional waterproofing and weatherproofing. The shaft is provided on one side at the pivoting end of the closure and includes an engaging pivot shoe that rides in the track which includes a pinion gear that engages the rack in each track of the header and sill. The opposite side of the closure, namely the free end, is designed with an inter-engaging extrusion that works as an interlocking portion to secure each closure to one another whether in the closed position or the fully pivoted position. As a result no visible hardware is seen on the outside except for a casement handle on the first sash on the inside. The multiple shafts at the pivoting ends of the closures also serve to reinforce and strengthen the entire window by co-operating in an interlocking manner with the inter-engaging members at the free ends of the closures.
According to yet another aspect of the invention there is provided a closure assembly including multiple closures for example casement French doors, patio doors or the like which provide an improved appearance and clean straight line or in line appearance in a parallel closure assembly because of the unique pivoting and interlocking edge.
According to yet another aspect of the invention there is provided a closure assembly having two ends comprising first and second tracks disposed within the full length of a header and sill portion of said closure assembly proximate the top and bottom of the assembly respectively and extending from jamb to jamb of said assembly, at least three slidable and pivotable closure members for movement in relation to said tracks, the closure members including framing sections therefor and being engaged with the tracks proximate first and second pivots adjacent the pivoting end of each closure member, the first and second pivots being interconnected by a multiple segment shaft disposed within framing sections of said closure members, the shaft including at least two portions, the shaft providing for accurate installation, retention, removal, adjustment and alignment of the first and second pivots within the tracks in a substantially parallel line with respect to one another and for pivotally supporting the closure members which may be safely and securely pivoted away from the closure assembly, whereby the first and second interconnected pivots are adapted to remain engaged with the tracks while supporting the closure member both when it is pivoted away from the closure assembly and when it is slidable relative to the tracks, the closure members having a free end and a pivoting end with inter-engaging members proximate the free end of each closure member, which engage the adjacent closure member proximate the free end thereof when said closure members are pivoted to a fully open position and further positioned whereat the pivoting ends of said closure members are also located adjacent one another to provide a maximum opening to exit or enter a building at this position for example when said closure assembly is for a patio door, and wherein when said closures are at a fully closed position when adjacent pivot ends and free ends inter-engage and seal with respect to one another to present a shared plane, straight line in line flush appearance for all closures in relation to said closure assembly.
According to another aspect of the invention there is provided a closure assembly comprising:
1) an opening extending within a closure frame
ii) the frame having two ends and having disposed therein or attached thereto track portions extending substantially parallel to said frame; iii) at least three closure members having framing portions and two ends and being slidable within said track portions and pivotable proximate at least one end thereof and latchable in the track portions proximate the free end thereof; iv) each of said track portions having disposed therein at least one pivot shoe adjacent the pivoting end of each closure member, each shoe being substantially compatibly shaped with the track portions and having a top and bottom, each shoe having disposed therein adjacent the pivoting end of the at least three closure members an opening extending from the top toward the bottom of the shoe wherein pivot means are disposed, said pivot means provided with said pivot shoe being interconnected by a multiple segment shaft disposed within said framing portions of said at least three closure members, the shaft including at least two portions, the shaft providing for accurate installation, retention, removal, adjustment and alignment of the first and second pivots within the track portions in a substantially parallel line for pivotally supporting the at least three closure members for safe and secure pivoting away from the closure assembly; v) two closure members having latching means provided therewith for latching the two closure members in relation to the track portions to prevent the two closure members from pivoting upon the pivot means when each closure member remains slidable with said track portions; vi) the at least three closure members being braced by the multiple segment shaft interconnecting the pivot means disposed with each of the track portions, the substantially parallel alignment of the pivot means provided by the multiple segment shaft preventing the pivot means from misaligning or disengaging from the relevant track portions when each closure member is rotated to an open position or when it remains slidable within said track, (vii) the closure members having a free end and a pivoting end with inter-engaging members proximate the free end of each closure member, which engage the adjacent closure member proximate the free end thereof when said closure members are pivoted to a fully open position and further positioned whereat the pivoting ends of said closure members are also located adjacent one another to provide a maximum opening to exit or enter a building at this position for example when said closure assembly is for a patio door, and wherein when said closures are at a fully closed position when adjacent pivot ends and free ends inter-engage and seal with respect to one another to present a shared plane, straight line in line flush appearance for all closures in relation to said closure assembly.
Preferably the first and second pivot portions further comprise a rotatable pinion disposed therewith for facilitating the movement of the carrier relative to the track.
Preferably the rotatable pinion moves in cooperation with a rack disposed with said track.
More preferably retractable screens are provided disposed within each jamb of the assembly which accumulates on and pays out (feeds out or rolls out) from a spring biased roll disposed within each jamb, the screen being retractable for egress or cleaning purposes, and available as desired by providing a detent on the opposite screen handle or closure frame engageable with the screen when in its operable position.
In a preferred embodiment a pivot shoe is provided for engagement with said rack and track further comprising a carrier having a top and a bottom, the carrier having disposed proximate the bottom thereof means, and preferably slots, for retaining rollers, and the rollers in use thereof for providing the smooth movement of the carrier within the track, preferably the rollers being engaged with a predetermined channel formed in said track, said carrier also having an opening disposed proximate the top thereof wherein a pivot gear is disposed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front interior view of a frame assembly wherein multiple closures move in a horizontal direction, and pivot outwardly from said frame illustrated in a preferred embodiment of the invention.
FIG. 2 is a front view of the frame assembly of FIG. 1 embodying the invention and depicting the use of rollout screens and illustrated in a preferred embodiment of the invention.
FIG. 3 is a perspective view of the frame assembly of FIG. 1 depicting the inter-engagement members in a preferred embodiment of the invention.
FIG. 4 is a similar view of the frame assembly of FIG. 3 depicting closure 35 thereof in an open position and illustrated in a preferred embodiment of the invention.
FIG. 5 is a perspective view of the components of the hardware of FIG. 3 to be installed in a multi closure member assembly.
FIG. 6 is a further perspective view of FIG. 1 with all closures at the pivoted position illustrated in a preferred embodiment of the invention.
FIG. 7 is a further view of the closures of FIG. 6 with the members 34 and 35 both pivoted and moved laterally to a position whereat the free ends of said members inter-engage by inter-engaging members 34 m and 35 m.
FIGS. 8A and 8B are yet further schematics and front views of the assembly of FIG. 7 illustrating the closure members at a position allowing for the maximum opening available for exiting the building and illustrated in a preferred embodiment of the invention.
FIG. 8C is a top view of FIG. 8A .
FIG. 9A is a close-up view of the assembly adjacent the top of closure 31 showing the preferred rollout screen assembly.
FIG. 9B is an exploded view illustrating a screen cassette of prior art.
FIG. 10 is a close-up perspective illustration of the free end of closure member 32 with the inter-engaging member 32 m installed at the free end of the closure member and illustrated in one embodiment of the invention.
FIG. 11 is a close-up top view of the inter-engagement members shown in FIGS. 8A and 8C and illustrated in a preferred embodiment of the invention.
FIG. 12 is a similar view to FIG. 11 illustrated in a preferred embodiment of the invention.
FIG. 13 is a perspective view of the closure assembly of FIG. 1 illustrating the operation of latching pin P and the engagement of a pivoting end with a free end of adjacent closures.
FIGS. 14, 15 and 16 are prior art.
FIGS. 17A-C and 18 A-C Illustrate one of the embodiments of the current invention in different operational states.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a front schematic view of the present invention illustrating five adjacent casement style closure members such as doors or window sashes 31 - 35 which are interconnected when at the closed position as shown. A special inter-engagement member ( 32 m - 35 m ) is disposed adjacent the free end ( 32 d - 35 d ) of each closure as best seen in FIG. 6 and provided for each closure with the exception of the closure member 31 at 31 d.
A closure framing section 11 ( FIG. 1 ) therefore is provided including a header 10 and a sill 20 with opposite jambs sections J 1 and J 2 . The header section 10 may be reinforced or alternatively there may be contained within said frame above said header as necessary a lintel or the like to increase the load carrying ability of this assembly 11 . A pivot shaft (T) ( FIG. 13 ) is disposed at the pivoting end ( 31 b - 35 b ) of each closure member 31 through 35 . Each closure member includes framing sections ( 31 a - 35 a and 31 c - 35 c ) as well. A handle h is disposed on the left side of the closure member 31 .
Referring now to FIG. 2 there is shown the invention of FIG. 1 further enhanced by a roll screen system S 1 , S 2 which will be described hereinafter and is best seen in detail in a FIG. 9A . U.S. Pat. No. 6,405,781 also assigned to the present assignee provides the essential teachings of such a roll screen assembly which is incorporated by reference in relation the provision of a pocket in a jamb section of the closure frame and the compatible shape of a pivot bracket with said pocket.
Referring to FIG. 3 the closure assembly is illustrated showing the inter-engaging members 32 m - 35 m when in the closed position. These members also inter-engage at the fully open pivoted position to brace the assembly against any loading including wind loads. Please refer to FIGS. 8A and 8C in this regard.
Referring to FIG. 4 and FIG. 12 the closure assembly is shown with the closure member 35 m at an open position as seen from the interior of the building. The pivot assembly having a multiple segment shaft, first and second pivots, racks and pinions, is constructed according to the teachings of U.S. Pat. No. 5,687,506 as seen in FIGS. 14 through 16 the details of which are incorporated by reference in their entirety in relation to the teachings of the construction of the shaft ( 30 ), the pivot shoe ( 39 ), the rack 18 and cooperating pinion 35 .
Referring to FIG. 5 there is illustrated the closure assembly 11 from FIG. 1 with the framing members 10 and 20 removed, showing inter-engaging members 32 m - 35 m , a track 17 in the header and a track 16 in the sill.
Referring to FIG. 6 there is illustrated the closure assembly with all closures 31 - 35 shown in perspective pivoted away from said closure frame on their respective pivots. However each closure has yet to be moved in the track on its pivot shoe. In FIG. 7 closures 34 and 35 are shown with the pivot ends adjacent one another and the free ends thereof braced together by the inter-engagement of members 34 m and 35 m in FIG. 7 , and as best seen and described in relation to FIG. 11 .
FIGS. 8A and 8B illustrate all closures 31 through 35 at the pivoted position providing the largest opening possible for entry or exit from the interior of the building. The screen assembly S 1 may be used to cover that opening when not used to prevent insects from entering. Alternatively sunscreens or shades can be used which can be secured at the various positions shown herein, such as FIG. 5 . The free ends of the closures (d) are braced to one another by bracing elements also referred to as inter-engaging members 32 m through 35 m , the details of which will be described hereinafter. In alternative embodiments other assemblies may include entry doors, French doors, patio doors, casement windows or the like as illustrated in FIG. 1 . Very large “Window Walls” can be provided which in the example illustrated in FIG. 1 cover 15 foot openings which is heretofore unknown, and therefore open up many possibilities to interior design.
As best seen in FIG. 8C and FIG. 5 a multiplicity of openings (o) are in track 17 and track 16 for drainage purposes. Further rollout screen assemblies S 1 and S 2 are shown hidden in the jamb pockets when not used but having handle assemblies butted together and secured as shown. FIG. 9A illustrates the pocket Pk from which the screen assembly pays/rolls/feeds out as taught in the aforementioned patent U.S. Pat. No. 6,405,781 the details of which are illustrated in FIG. 9B . The reader is referred to the description of FIG. 48 in that document the teachings of which are incorporated by reference herein in full.
Referring to FIGS. 10, 11 and 12 , the pin assembly P is spring biased to a channel in the frame and includes a shoulder P 2 which releases from the channel when an opening motion of said closure is applied sufficient to overcome the force of the spring. This action permits the closure to move away from the closure frame in the opening direction at any position on the tracks.
When the closure is moved to the closed position the pin P engages the interior of the closure frame via blunt face P 1 and is returned to its position in the channel.
In FIG. 10 , the inter-engaging member 32 m has two fingers 32 x and 32 y , and a foot 32 z . In FIG. 11 , the foot 32 z is inter-engaged between fingers 33 x and 33 y of the inter-engaging member 33 m . In FIG. 12 , the inter-engaging members 32 m - 35 m are interlocked in a similar manner.
Referring to FIG. 13 there is illustrated the engagement of adjacent closure members at the free end ( 33 d ) and the pivoting end ( 32 b ) when at the closed position. The closure 33 on the right is free to pivot in an opening direction when sufficient force is applied by pushing on the closure in an opening direction to overcome the spring provided with the pin P. No handle is therefore necessary to do so. This is true for all closures 32 through 35 previously illustrated.
FIGS. 14 to 16 illustrate the pivot assembly of U.S. Pat. No. 5,687,506 used in the present closure assembly the teachings of which are incorporated by reference in their entirety herein. FIG. 14 illustrates a casement style window wherein only one sash is provided which is fastened on shaft assembly 30 including portions 31 and 32 . A link L is provided secured proximate ends L 1 adjacent the center of the sash 21 proximate the bottom thereof and adjacent the rack 18 adjacent the opening end of the window sash 21 . By positioning the sash in this manner a full range of pivoting motion is available. If the link end L 1 is removable from the sash, then the window sash may be moved totally to the opposite end remote the pivoting end 21 b on shoe 39 . Shoe 39 contains a pinion 39 a which is connected to the shaft 30 and engages the rack 18 as it moves along the window sill and header in parallel arrangement between the upper and lower pivots maintained in parallel by the shaft 30 . In this manner the casement style window may be pivoted as normal to an open position, and the pivoting end may be moved to the other end of the window frame away from side 21 b to allow ease of cleaning. By supplying the hardware described herein, a casement window may be assembled without the need for expensive pivots and linkages and without a great deal of assembly labour. As seen in FIGS. 9A and 9B , a rollaway screen S 1 may be provided which is housed in the jamb channel as illustrated. The screen S 1 pulls across to engage detent D 1 with detent D 2 in the opposite channel jamb, whereat it may be locked. This allows a user to clean the glass on the inside without the need to remove the screen as in prior art casement structures.
FIG. 15 illustrates a two sash window in which sashes 20 and 40 are slidable within lower track 16 and upper track 17 upon upper and lower shoes 39 . The lower shoe 39 may also be connected to a secondary shoe 39 a as desired for carrying the window which includes rollers 39 b on the bottoms thereof respectively for ease of movement within track 16 . The pinions 35 rest within each shoe 39 which engage with the lower rack 18 and upper rack 15 . Sash 40 has its own interconnected system which is not illustrated here.
FIG. 17A illustrates a two pane closure 111 with the left closure 131 open and right closure 132 shut as best seen in FIGS. 17B and 17C . In this illustration the two bug screens S 1 and S 2 are in a closed position abutting proximate the center of the opening. FIGS. 18A-C illustrates the same embodiment of the closure with two panes 131 and 132 while the right pane 132 is moved to the left of the closure as best illustrated in FIGS. 18B and 18C . In this position the pivoting ends 131 b and 132 b are close together and free ends 131 d and 132 d are inter-engaged by the inter-engaging member 132 m . The bug screens S 1 and S 2 in this embodiment are also closed.
As many changes can be made to the preferred embodiments of the invention without departing from the scope thereof. It is intended that all matter contained herein be considered illustrative of the invention and not it a limiting sense.
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A closure assembly comprising at least two closures moveable in a closure frame, said closure frame including a header, sill and including a track sized to extend the full-length the header and sill thereby providing for guided movement of each individual closure to the maximum extent to and from a fully closed position, the at least two closures presenting a straight line, in-line, closure, such as a window, entry door, French door, patio door assembly and when the closures are pivoted from a closed position whereat said closures are parallel to the extension of said closure frame to a second position wherein free end of the closer is pivoted away from the closure frame, the free end of said closure including an inter-engaging member which inter-engage with adjacent members to brace together said closures thereby against any loading such as wind loads or the like.
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The United States Government has rights in this invention pursuant to Contract No. DE-AC04-76DP00789 between the United States Department of Energy and American Telephone and Telegraph Company.
BACKGROUND OF THE INVENTION
The present invention relates generally to a device and method for injecting bridging materials and cementitious mud downhole for the purpose of controlling severe lost circulation and, more particularly, to a device and method for emplacing a quick-setting cement downhole while ensuring that premature setting does not occur inside the drill pipe. This invention is useful for any downhole or drilling operation where the problem of lost circulation is likely is occur, e.g. oil and gas drilling, geothermal drilling, coring operations, and mineral exploration.
Lost circulation is the phenomenon where circulating drilling fluid is lost to fractures or pores in the rock formation rather than returning to the surface through the wellbore annulus, as it does during normal drilling. In a wellbore, drilling fluid, such as cementitious mud, is pumped downhole and circulates to the surface to cool the bit, to carry rock chips out of the borehole, and in some cases to control the well; when lost circulation occurs, this fluid is lost to the rock formation due to an incompetent or permeable rock formation (characterized by a porous matrix, fractures, vugs, or caverns) which does not have adequate physical integrity or pore-fluid to support the hydrostatic pressure inside the wellbore.
Although drilling can continue under lost circulation conditions, it is generally imperative that the fluid loss be stopped as soon as possible after it is discovered for various reasons: the loss of the drilling fluid itself to the formation is expensive; changes in the rock formation being drilled cannot be easily detected if rock chips are not circulated out of the wellbore; rock chips lost to the formation can flow back into the wellbore when drilling stops, thus sticking to the drillstring in the hole; control of the well may be difficult or impossible if a high-pressure zone is encountered with the wellbore only partially filled with drilling fluid; drilling fluid invasion of the surrounding rock formation alters in-situ conditions and therefore affects the logging response of the formation; freshwater aquifers associated with loss zones can be contaminated by drilling mud and connate fluids (fluids trapped in the sediment and/or rock) produced at different wellbore intervals; and loss zones not treated during the drilling phase can cause casing cement to be lost to the open formation during completion operations, resulting in a poor or incomplete bond between the casing and the rock formation and requiring expensive remedial action to prevent inter-interval flow and (in geothermal wells) possible casing collapse when the well is put on production.
Lost circulation is a major problem in oil and gas well drilling and other types of exploration with the advent of exploration in deeper, more highly fractured producing formations; however, lost circulation problems tend to be more severe in geothermal drilling than in other types of drilling because of the highly fractured and underpressured nature of many geothermal formations. Bridging materials (i.e. the particles added to drilling mud to form a bridge or a plug across a fracture) used as drilling mud additives for lost circulation control in oil and gas drilling are ineffective in plugging large fracture apertures, particularly under high-temperature conditions. Therefore, the standard lost circulation treatment in geothermal drilling is to fill the loss zone surrounding the wellbore with cement, which is both expensive and time-consuming due to the necessity of waiting for the cement to harden and then drilling through the cemented zone to reach new rock formation.
In geothermal drilling, lost circulation is typically the most costly problem routinely encountered. In mature geothermal areas, lost circulation costs represent an average of 10% of the total well costs, and in exploratory wells and developing fields, lost circulation costs often account for over 20% of total well costs.
Various methods and apparatus are known for delivering materials into the wellbore and/or for providing fluid access to the wellbore annulus, but most do not address the problem of lost circulation control.
U.S. Pat. No. 3,799,278 to D. L. Oliver described a downhole tool for providing fluid access to the wellbore annulus through the side of the drill pipe using a dropped dart or wireline in order to restore drilling mud circulation if the drill bit nozzle becomes clogged during operation. U.S. Pat. No. 4,072,166 to Tiraspolsky et al. describes a downhole tool for providing fluid access from the wellbore annulus to the drill pipe interior through the side of the pipe using the pressure drop of the flowing fluid to operate a valve, the purpose of the invention being to ensure the axial flow of fluid injected into the drill pipe during drilling while allowing interruption of the axial continuity and connecting the interior of the pipe directly with the exterior annulus space when the injection is broken off or when the flow descends below a minimum value.
U.S. Pat. No. 4,645,006 to Tinsley describes a downhole device for providing access to the wellbore annulus through the side of the drill pipe using the drill pipe internal pressure acting on a dropped actuator to open a sliding access valve, in order to restore the circulation of drilling mud if the drill bit nozzle becomes clogged during operation. U.S. Pat. No. 4,823,890 to Lang describes a reverse circulation drill bit and associated apparatus in a permanent concentric tubing arrangement for directing the flow of drilling fluids through the bit in a reverse circulation mode.
Thus, both the direct costs, and the unknown costs associated with possible contamination of freshwater aquifers, as well as other problems related to lost circulation control indicate an existing need for a system providing major-fracture fluid loss control. More particularly, there is an existing need for technology to plug major-fracture loss zones.
In addition to cost considerations, when the maximum thickness of the loss-zone fractures is greater than the diameter of the drill bit nozzles, it is not possible to plug the loss-zone with drilling mud additives without also plugging the bit nozzles. In such cases, it is necessary to use a material that either solidifies after it flows through the bit or is emplaced downhole after first removing the bit. In geothermal drilling, various cement formulations are pumped downhole for plugging major-fracture loss zones. While these cement treatments are generally effective in stopping fluid loss, they are expensive in both the quantity (hundreds of cubic feet) of cement required and the long waiting time (8-12 hours) for the cement to set before drilling can resume.
A new class of cementitious material is known as cementitious mud, which consists of bentonite drilling mud with added constituents for turning it into solid form, usually including an accelerator material for controlling the setting time. The formulations are developed to provide rapid-setting, temperature-driven, cements in which significant compressive strengths may be developed within short times. As an example, a cement formulated by mixing conventional bentonite mud with ammonium polyphosphate, borax, and magnesium oxide has been developed which attains significant compressive strength in less than two hours when sufficient concentrations of the magnesium oxide accelerator are used; the setting time decreases with temperature, and the material expands approximately 15% upon setting.
Even with the potential benefits derived from the use of these muds for plugging purposes, there is a problem with lack of control over the setting process to ensure that the fluid will not set up inside the drill pipe during field application. Thus, there is an existing need for an alternative emplacement technique for more effectively and economically plugging loss zones dominated by large fractures, vugs, and caverns. There is also an existing need for an alternative emplacement system that provides more control over the setting process in the hole so that the cementitious mud will not set up inside the drill pipe during field operation.
In an effort to find alternative materials for more effectively plugging major-fracture loss zones, cementitious muds with an encapsulated accelerator have been developed. Specifically, the accelerator, typically the magnesium oxide additive, is encapsulated with an inert material that is sheared off by fluid action at the bit nozzles. The inert material used for the encapsulant for the accelerator may be one of many materials. In this technique, the cementitious mud is mixed at the surface and pumped downhole, but since the accelerator is shielded from the other cement constituents by the inert encapsulant, the cement does not harden in the drill pipe regardless of the time required for pumping. As the cement flows through the nozzles, the encapsulant is sheared off, exposing the accelerator and initiating the cement setting process. The chemical setting reaction is then further accelerated as the cementitious mud flows into the high temperature formation. However, questions exist as to the timing and reliability of the encapsulation technique.
There is an existing need for an alternative system for emplacing cementitious mud downhole in case the encapsulation technique is unworkable, either consistently or at some proven parameters.
Known apparatus and methods for delivering plugging materials to the wellbore that do address the problem of lost circulation are subject to the necessity of avoiding premature set-up of the plugging material and the problems associated therewith. U.S. Pat. No. 4,378,050 to Tatevosian et al. describes a downhole tool for delivering a pre-mixed plugging material in a container to the bottom of a drill pipe and injecting it into the wellbore through the bit using a displacing agent (mechanical, fluid, or gas) to force the plugging material into the bit, with the goal of plugging a lost circulation zone. U.S. Pat. No. 4,842,066 to Galiakbarov et al. describes a downhole device for injecting a single stream of pre-mixed cement slurry downhole through the drill pipe to the location of a lost circulation zone in order to accomplish downhole separation of the components of a single fluid stream of cement slurry into a solid and liquid phase, with the purpose of plugging the lost circulation zone.
There is an existing need for a method and corresponding system for quickly and economically plugging lost circulation zones without requiring pulling or tripping the bit.
There is also an existing need for a method and corresponding system to allow the components of a two-component plugging material, such as cementitious mud, to be placed downhole simultaneously but separately, without mixing the components prior to emplacement in the wellbore, for lost circulation control.
SUMMARY OF THE INVENTION
In view of the above-described needs, it is an object of this invention to provide an alternative emplacement device and method for more effectively and economically plugging loss zones dominated by large fractures, vugs, and caverns.
It is another object of this invention to provide an alternative emplacement device and method for providing more control over the setting process in the hole so that the cement will not set up inside the drill pipe during field operation.
It is a further object of this invention to provide an alternative emplacement device and method for emplacing cementitious and downhole in case the encapsulation technique is unworkable, either consistently or at some proven parameters.
It is still another object of this invention to provide a method and corresponding system for quickly and economically plugging lost circulation zones without requiring pulling or tripping the bit.
It is an additional object of this invention to provide a method and corresponding system to allow the components of a two-component plugging material, such as cementitious mud, to be placed downhole simultaneously but separately, without mixing the components prior to emplacement in the wellbore, for lost circulation control.
Additional objects, advantages, and novel features of the invention will become apparent to those skilled in the art upon examination of the following description or may be learned by the practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the foregoing and other objects and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a downhole injector system for providing the components of a two-component plugging material, such as cementitious mud, to be placed downhole simultaneously but separately, without mixing the components prior to emplacement in the wellbore, for lost circulation control. More specifically, in a first embodiment according to the invention, the downhole injector system includes a separate tubing assembly which acts in conjunction with the drill pipe to deliver an accelerator slurry, or more specifically a magnesium oxide slurry, and a cementitious mud slurry downhole into the wellbore. In a second embodiment, the downhole injector system also includes an insert injector assembly installed in the drill pipe with which a portion of the tubing assembly mates to deliver the separate components of the slurry to different locations downhole prior to their mixing. The insert injector assembly includes a valve that opens to direct the accelerator slurry out of the side of the drill pipe and into the wellbore annulus above the bit. At the same time, a slurry of cementitious mud, or more specifically a slurry of bentonite mud, ammonium polyphosphate, and borax is pumped through the drill string and bit nozzles in the normal manner. The bit is situated above the loss zone, so that the two slurry streams exit the injector in separate locations, then enter the loss zone and mix, thereby initiating the chemical reaction that hardens the mud into cement.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and form part of the specification, illustrate an embodiment to the present invention and, together with the description, serve to explain the principles of the invention.
FIG. 1 is a plan view in cross-section of the downhole material injector with the tubing assembly extended through the drill pipe to a location near the drill bit.
FIG. 2 is a plan view in cross-section of the downhole material injector showing the tubing assembly extended in the drill pipe with the mating section or sealing head approaching the insert or injector assembly.
FIG. 2a is a cross-sectional view of the injector assembly sectioned at the sliding valve, shown as A--A on FIG. 2.
FIG. 3 is a detail view in cross-section of the downhole material injector showing the tubing assembly extended in the drill pipe with the sealing head approaching the injector assembly, which has its valve in closed position.
FIG. 4 is a plan view in cross-section of the downhole material injector showing the tubing assembly extended in the drill pipe with the sealing head engaged in the injector assembly.
FIG. 5 is a detail view in cross-section of the downhole material injector showing the tubing assembly extended in the drill pipe with the sealing head engaged in the injector assembly, which has its sliding valve in its open position.
DETAILED DESCRIPTION OF THE INVENTION
As shown in the FIGS. 1, 2, and 4, drilling assembly 1 includes drill string 10. Drill string 10 is typical of common drill strings and may be defined here as all the subsurface parts of drilling assembly 1, or all the downhole structural parts that hang into the wellbore from the drill rig (not shown). FIGS. 1, 2 and 4 also show the surface below which the drill string 10 extends and the loss zone of the formation. Drill string 10 includes drill pipe 11 having a hollow center, drill collars 12, crossover sub 13, and drill bit 14 having nozzles 15.
Drill collars are known in the art as the thick-walled central section of the drill pipe, which provide weight to the drill string to push the drill bit into the subsurface formation. The drill collar section of the pipe typically has the same inner diameter as the top portion of the drill pipe, but an increased outer diameter.
Crossover subs are also generally known in the art as the section of the threaded connector that attaches the drill bit to the drill collar section of the drill pipe. The drill bit is the attached tool for cutting into or crushing the rock formation for the purpose of advancing the wellbore. The nozzles are the openings in the bit to the wellbore from which drilling fluid exits the drill string. FIG. 1 is sectioned on the nozzle end of the drill string to show no actual nozzle(s) but rather an open area 15, representing the available fluid exit from the drill string.
There are many known structural configurations of drill bits, which, depending on the type of exploration activity being pursued, may have from one to multiple nozzles. In oil and gas and geothermal drilling, two types of drill bits are widely used, one having cutters and multiple nozzles, the other having rotating cones and three nozzles. At least three nozzles are typical, but for the purposes of this description, FIG. 2 shows only two nozzles 15.
A first embodiment of the invention is shown in FIG. 1 and includes tubing assembly 20, having a hollow center throughout and a surface portion 21 including a coiled upper end 22 with an entrance port 23 for the injection of the accelerator material, typically bridging material, MgO and water, into the drill pipe. Surface portion 21 also includes a head 24 which is threaded at its lower end 25 for connection of the entire tubing assembly 20 to drill string 10, and contains a second entrance port 26 for the provision of the cementitious mud slurry to the drill pipe 11. The entire lower portion of tubing assembly 20, at the opposite end of assembly 20 from the coiled surface portion 21, comprises a stinger tube 30 which is lowered into drill pipe 11 by winding and unwinding of coiled end 22.
Stinger tube 30 is the section of tubing assembly 20 that has a weighted wall to facilitate its travel down the hollow center of drill pipe 11. Stinger tube 30 includes upper centralizing fins 31, sealing head 32 located considerably beneath upper centralizing fins 31 on tubing assembly 20 and having angled upper and lower surfaces 33aand 33b, respectively, and small centralizing fins 34 attached to its outer circumference. Upper centralizing fins 31 act to space tubing assembly 20 inside drill pipe 11. The sealing head 32 is a short, thicker walled section of tubing assembly 20; its small centralizing fins 34 also act to center and stabilize sealing head 32 inside drill pipe 11.
The basic operation of this first embodiment of the invention is apparent. During normal drilling, fluid and/or drilling mud is pumped down through the drill pipe 11 and out the drill bit nozzle(s) 15 to circulate through the wellbore annulus (the area of the wellbore or hole surrounding the drill string) and back to the surface. When a lost circulation zone is encountered, drill string 10 is pulled up such that bit 14 hangs just above the loss zone. Drill string 10 is disconnected from the draw works (not shown) at the rig floor, and head 24 is moved into connection with, and attached to, the top of drill string 10, as depicted in FIG. 1. Tubing assembly 20 with stinger tube 30 is passed through head 24 and coiled end 22 is advanced to control the lowering of stinger tube 30 into and through drill string 10 to the drill bit 14. Cementitious mud slurry is pumped into port 26 to flow through the hollow center of drill pipe 11, while a slurry of accelerator (and bridging material, if desired) is simultaneously pumped into port 23 to flow through the hollow center of tubing assembly 20. The flows of both materials exit drill pipe 11 and tubing assembly 20, respectively, at nozzle(s) 15 of drill bit 14 to mix together below bit 14 as they flow into the loss zone in the formation below drill string 10, thereby starting the chemical reaction that hardens the cement.
A second and preferred embodiment of the invention is shown in FIGS. 2, 3, 4, and 5. In this second embodiment, injector assembly 40 is inserted into drill pipe 11 above crossover sub 13. Unlike tubing assembly 20 which is separate and not a permanent part of drill string 10, injector assembly 40 may be formed as a permanent part of drill pipe 11. Referring to FIG. 3, injector assembly 40 generally comprises a short tubular section 41 of drill collar, fastened into drill pipe 11, and fitted with sliding valve 42 and side ejection port 43.
As seen in more detail in FIGS. 3 and 5, valve 42 also includes at its lower end spring 44 and piston 45 immediately above spring 44. Spring 44 acts in conjunction with stinger tube 30 to open and close valve 42, as set out in more detail below. Sliding valve 42 also includes beveled lip 46 at the uppermost end, as well as three O-rings 47, 48, 49, spaced along the outer diameter of the piston 45. Piston 45 moves axially inside cylinder 50, which is attached to section 41 with fins 51, or equivalent structure, at two or more locations around cylinder 50. Side ejection port 43 consists of the open passage through a tube 52 that extends radially from a hole in the side of cylinder 50 through a hole in the wall of drill collar 41.
The operation of the second embodiment of the invention is essentially the same as that of the first embodiment, except that stinger tube 30 acts as a mating part. During normal drilling, injector assembly 40 is passive, allowing drilling fluid to pass through passages 60 (shown in FIG. 2A) between cylinder 50 and section 41, with no significant restrictions and little pressure drop. Spring 44 keeps valve 42 in its raised, closed position, thereby preventing drilling fluid from flowing out side ejection port 43. As with the first embodiment, when a lost circulation zone is encountered, drill string 10 is pulled up to bring bit 14 just above the loss zone. Drill string 10 is disconnected from the draw works, and head 24 is moved into connection with, and attached to, the top of drill string 10, as shown in FIGS. 2 and 4. Tubing assembly 20 with stringer tube 30 is passed through head 24 and lowered toward injector assembly 40 through drill string 10. FIGS. 2 and 3 are schematics showing stinger tube 30 just prior to reaching injector sub 21, and sliding valve 42 in its closed position.
Centralizing fins 34 on sealing head 32 of stringer tube 30 and beveled lip 46 of injector assembly 40 act to ensure that the end of stinger tube 30 passes into sliding valve 42 and contacts the top of piston 45. The weight of stinger tube 30 overcomes sliding valve spring 44, thereby forcing piston 45 down to its open position. The weight of stinger tube 30 also forces angled surfaces 33b on sealing head 32 to contact the matching surfaces of beveled lip 46 of sliding valve 42. An O-ring 36 carried in sealing head 32 provides a fluid seal necessary to segregate fluid inside stinger tube 30 from fluid inside drill string 10. An additional O-ring 37 in the terminal end 35 of the stinger tube 30 provides secondary sealing in case O-ring in sealing head 32 fails. FIGS. 4 and 5 are schematics showing stinger tube 30 engaged in injector assembly 40 and sliding valve 42 in its open position. Injector assembly 40 may also include, active clamping devices (not shown) to connect stinger tube 30 to sliding valve 42, but the weight of stinger tube 30 alone should be sufficient to open valve 42 and provide the necessary sealing.
After stinger tube 30 is in place with sliding valve 42 open, a mixture of cementitious mud, typically bentonite, ammonium phosphate (AmPP), borax, and water is pumped downhole through drill string 10 including assembly 40, out bit nozzles 15, and into the wellbore and loss zone. At the same time, a mixture of accelerator materials, typically MgO, bridging materials, and water, is pumped down the tubing assembly 20, through stinger tube 30 and sliding valve 42, out side ejection port 43, and into the wellbore annulus and the loss zone. Again, the two fluid streams mix together below bit 14 as they flow into the loss zone, thereby starting the chemical reaction that hardness the cement.
The outside diameter of injector assembly 40 is typically in the area of 6-9 inches. The inside diameter of drill string 10, including drill pipe 11, is in the area of 3-5 inches. Stinger tube 30 consists of approximately 30 feet in length of small-diameter, heavy-wall pipe, weighing approximately 200-500 pounds. Tubing assembly 20 and stinger tube 30 each have inside diameters of approximately 1 inch, thereby allowing ample flow area for the accelerator fluid as well as relatively large bridging material particles, such as up to 1/3 inch in diameter. The ability to pass such large particles is extremely desirable in providing temporary plugging of fractures, with the hardened cement acting to make the plugs permanent. The structure of side ejection port 43 is also useful in this regard because particles too large to pass through bit nozzles 15 may be emplaced downhole through port 43. It is considered desirable to space injector assembly 40 as close as possible to drill bit 14, typically within 5 feet, for purposes of enhanced mixing.
The relative sizes of the tubing assembly 20 and the entire drill string 10 are also well matched to the concentrations of MgO accelerator required to provide rapid setting of the cement. Typical flow rates down the drill string range from 100-150 gpm, while those down the coiled tubing range from 5-20 gpm.
To prevent sticking drill bit 14 with bridging materials, the entire drill string 10 may be reciprocated in a vertical plane using the drill rig draw works (not shown).
Although simple, the downhole material injector should provide significant reliability. Other advantages of both the structure and the method of all embodiments of the invention include the ability to operate without tripping drill string 10 out in order to emplace the cement. Tripping and removal of the bit 14 is done with conventional cements because of the fear of pumping such cements through the bit nozzles 15. If premature thickening of the cement occurs, the small restrictions provided by the nozzles 15 could cause the cement to set up in the drill pipe before it can be tripped out. Cementitious muds do not readily set up without the addition of the accelerator; thus the pumping operation according to the invention can be safely done without pulling bit 14. Also, tubing assembly 20 can be run downhole in a relatively short time, thus saving considerable time over that required for conventional cement treatments.
In wireline coring or other exploration applications of the invention, the embodiment of FIG. 1 with injector assembly 40 deleted is most appropriate. As previously explained, FIG. 1 is sectioned on the nozzle end of the drill string to show no actual nozzle(s) but rather an open area 15, representing the available fluid exit from the drill string. In this application, the core barrel used for wireline coring systems (i.e. the barrel for holding the rock core) is temporarily removed, and tubing assembly 20 is run down to the bit 14. Accelerator fluid and bridging material are discharged through the coiled tubing and out bit 14 directly into the fluid stream flowing down drill pipe 11.
The particular sizes and equipment disclosed above are cited merely to illustrate particular embodiments of the invention. It is contemplated that use of this invention may involve components having different sizes and other parameters as long as the principle described herein is followed. A downhole material injector assembly, constructed in accordance with the present invention, will provide the capability of pumping two fluid streams separately, but simultaneously, downhole in order to emplace a two-component plugging material, such as cementitious mud, downhole for lost circulation control without mixing the components prior to their emplacement in the wellbore. It is intended that the scope of the invention be defined by the claims appended hereto.
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Apparatus and method for simultaneously and separately emplacing two streams of different materials through a drillstring in a borehole to a downhole location for lost circulation control. The two streams are mixed outside the drillstring at the desired downhole location and harden only after mixing for control of a lost circulation zone.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of International Application No. PCT/DE02/03759 filed Oct. 7, 2002, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE DISCLOSURE
[0002] 1. Field of the Disclosure
[0003] The disclosure generally relates to a method and device for dispatching postal parcels.
[0004] 2. Brief Description of Related Technology
[0005] EP 1 053 798 A2 discloses a virtual post office box. The physically non-existent post office box can be rented by persons and is linked to the address of these persons. Postal parcels that are addressed to the virtual post office box are segregated from the sorting process and forwarded to the address of the renter. The renter can indicate the period of time during which the postal parcels are to be forwarded to a given address. By the same token, he can change this address by sending a notification to this effect to the postal service company.
[0006] U.S. Pat. No. 6,269,369 B1 describes a network-based contact manager with which selected address information of a first user can be made accessible to a second user. Changes in the address data of the first user are sent to the second user, and the address data are then updated in the address book of the second user.
[0007] With the known dispatching methods, the problem exists that the recipient of the shipment often cannot be reached at the time of the delivery. This is especially a drawback in delivering postal parcels that cannot be placed into conventional mailboxes.
SUMMARY OF THE DISCLOSURE
[0008] Disclosed herein is a postal parcels delivery method that is fast, reliable, and involves as little dispatching effort as possible. Accordingly, the method includes inputting a delivery address for the delivery of the postal parcels, and changing the delivery address according to one or more of a routine predefined by the recipient and a function of free compartments of at least one parcel compartment system. The method also includes delivering the postal parcels to the changed delivery address. The disclosed method allows a flexible delivery of postal parcels, and provides a flexible control of the dispatching process. Preferably, the desired delivery address here is treated like a virtual delivery address that can be changed as a function of the requirements of the customer or of the postal service company.
[0009] Additional features of the disclosed method may become apparent to those skilled in the art from a review of the following detailed description, taken in conjunction with the appended claims.
DETAILED DESCRIPTION
[0010] In order to combine great flexibility of the dispatching of the postal parcels with high reliability of the delivery, the delivery address and the time of the delivery are advantageously selected in such a way that the postal parcels reach the desired delivery location within a predefined delivery period and in that, within this prescribed delivery period, the delivery to the desired delivery address takes place under the anticipated dispatching sequence of the postal parcel.
[0011] The link between the recipient identification code and the delivery address can be freely changed and this can also be done according to a predefined procedure. A variable link between the recipient identification code and the delivery address translates into maximum flexibility for the postal service company as well as for the sender and for the recipient of the postal parcel. For example, in this manner, negotiation documents can be sent to a business person at the location where the negotiations are being held, or spare materials or special tools can be sent to a service technician at the place of use or to a delivery point located close to the place of use.
[0012] A change in accordance with a predefined routine is likewise advantageous. For example, a recipient might prefer to receive a delivery at his workplace during regular business hours, but might prefer the delivery to an electronic parcel compartment system while he is on his way home or else he might prefer the delivery to his home address after returning from work. A stored table containing the allocation of delivery times and delivery places allows the postal service company to make the delivery to the place desired by the recipient in each case.
[0013] The above-mentioned example of the delivery to an electronic parcel compartment system is another preferred example showing the execution of the method. Such a delivery to the electronic parcel compartment system is especially advantageous if it is to be expected that the recipient of the postal parcel does not want the postal parcel to be delivered to his home or workplace at the anticipated delivery time or else if he does not want such a delivery modality as a general rule. For example, all postal parcels or all postal parcels with a definable and changeable delivery interval can be delivered to the electronic parcel compartment system. For the postal service company, this eliminates the effort involved in a failed delivery attempt to an unwanted delivery address, including the logistic effort associated with this for storing or holding the postal parcel or else for attempting delivery again.
[0014] The use of the method entailing delivery to an electronic parcel compartment system is likewise advantageous for the customer of the postal service company since this saves him unnecessary trips to pick up postal parcels and he receives the postal parcel at the earliest possible point in time.
[0015] In the case of delivery to an electronic parcel compartment system, the flexibility of selecting the delivery location is especially advantageous. In this manner, especially a flexible allocation of individual electronic parcel compartment systems, or individual postal boxes, is possible.
[0016] In particular, the disclosed method can be used to flexibly deploy the electronic parcel compartment systems, or the parcel compartments contained therein. This makes it possible to provide especially recipient-friendly, pick-up periods that optionally cover a longer period of time and, if a postal parcel is picked up from the parcel compartment assigned to it, then—immediately after this postal parcel has been picked up—another postal parcel can be placed into the parcel compartment that has just become free.
[0017] The flexible selection of several potentially deployable electronic parcel compartment systems is another advantage for the customer. Thanks to the flexibility of the method used, this advantage for the customer can be utilized with relatively little effort by a logistic company executing the method.
[0018] The method allows the use of various modalities of delivery and forwarding. For example, when the customer of a merchant places an order, he indicates his postal number (customer number for this service) as well as a delivery location (parcel compartment system) for the delivery of the ordered products.
[0019] The post number contains a check digit so that the correctness can be checked.
[0020] The recipient identification code can be issued individually for each order and it can also be used for multiple orders. In the first step, the system tracks the issuing of a post number for each customer. However, it is also conceivable that, for each transaction, a number is issued that provides authorization to use the system. It is especially advantageous for the postal service company to assign a fixed recipient identification code to a customer of the postal service company.
[0021] The delivery address can refer to the entire parcel compartment system (as well as to the individual parcel compartment). Both definitions of the delivery address are included. The disclosed method can be adapted to the delivery address that is used in each case.
[0022] Addressing
[0023] When the recipient places his order with the merchant, he provides his billing address as well as an alternative delivery address. The address of the desired PACKSTATION (PACKSTATION address) is indicated in the delivery address. For purposes of unambiguously identifying the shipment as a PACKSTATION delivery and for identifying the customer, the post number has to be indicated, also in the delivery address. The PACKSTATION address is a customer-individual automat address or branch office address to which deliveries can be made. Preferably, the address consists of the following: post number, PACKSTATION and number, actual postal code, and city.
[0024] The addressing of the alternative delivery possibility is shown below by way of an example:
First name, last name John Doe or Doe 123456789 Second name field 123456789 Street, house number PACKSTATION 102PACKSTATION 102 Postal code, city 53113 Bonn 53113 Bonn
[0025] If possible, the house number is selected in such a way that no same house numbers/automat numbers are issued to adjacent postal code regions. Furthermore, the house numbers are three-digit numbers, and are divided into two fields, so that an unambiguous allocation of the automat and the branch office is ensured. The house number range is defined as 001-499 for automats and as 500-999 for branch offices. An automat in a branch office is designated and addressed as an automat. The numbering of the automats/branch offices is not done separately for each postal code, but rather according to defined postal code regions, for example, 53 or the city area of Bonn, that is to say, in a postal code district, here in the 53 district, the house numbers are issued consecutively on an overarching basis. Adjacent postal codes start with a different numbering.
[0026] The numbering is done according to PACKSTATIONS, as shown below, for examle. These are especially parcel compartment systems or branch offices that are integrated into the logistic system and that serve for picking up the parcels.
53113 53152 53114 53110 PACK- PACK- PACK- PACK- STATION 1 STATION 2 STATION 3 STATION 4 . . . 54025 54320 . . . . . . PACKSTATION 101 PACKSTATION 102 . . .
[0027] Advantages of this form of addressing include, but are not limited to, expressive street names, better marketing possibilities, higher customer acceptance, the customer does not have to register separately for each automat, the geographic “postal code system” is retained, and no problems due to distortion of competition. Furthermore, the customer preferably has only one post number for all alternative delivery options. The post number is preferably, for instance, a 10 digit number that is assigned to a customer and that identifies him. Preferably, it is part of the delivery address as a suffix to the name. Disadvantages of this form of addressing include, more manual work for the in-house personnel, senders have to be thoroughly informed, and the transmission of the post number is secured.
[0028] The following table contains a presentation of preferred process steps.
[0029] Process
No. Process step Prerequisites Benefit Remarks 1. Address entry Entering the post According to the postal during the order number in the address standard, a second placement ordering process name field must be present. Provision of the check algorithm for the post number. 2. Gluing on the Printing option for Senders without By updating the LOS file, this parcel label by the the label with the master coding do point can be improved in the sender post number in the not have to handle future. Due to the product address field, PACKSTATION status as a PACKSTATION sender cannot print parcels separately. product, this can/will also be a master code covered by the SW shipment. 3. Transfer of the Standard process shipments to DPAG 4. Master coding in Update of the LOS The update of the LOS file for the sender's PZ file (post-internal) internal processing (PZ) can be realized up until the test phase. 5. Sorting in the Separate chute Negative freight center (B-final places) elimination of the PACKSTATION shipments, easier escalation possibilities 6. Reworking in Training the in- Entering the post The post number should be delivery basis house personnel, number can be applied onto the parcel by the (coding of the providing the dispensed with for in-house personnel as a customer number) SW/HW the delivery; reduction barcode sticker; by means of prerequisites of the potential a product identification for errors; simpler (product code), this can be loading of the done by the shipment SW; all automat on site information can also be integrated into the NC2001 (going-live not confirmed yet)?? 7. Delivery Scanning the post number; shorter loading times; correct time measurement 8. Return shipments Correct time measurement (retention time) 9. Standard process; Standard return shipment
[0030] Sequence Prerequisites
[0031] The sender has the possibility to accept and to activate an alternative delivery address and optimally an additional address line in his systems on the order form.
[0032] An automatic check of the delivery address, for example, in the on-line shop, in the goods management system or in the shipping logistic system, would have to be switched off, or would have to accept PACKSTATION addresses. The recipient has to know the PACKSTATION address and enter it himself. The post number should be indicated in the delivery address (=addressing of the parcel).
[0033] The prerequisites for the integration of an especially preferred embodiment are: defining the street designation; updating the LOS file; informing the central group BDV/LOS about the locations of the alternative delivery options; and, transmitting the post number from the ordering party via the sender to the local postal service provider (e.g., Deutsche Post AG).
[0034] In order to be able to realize a correct addressing of a print order (fax, letter) at post points, it is often necessary to implement a field for an alternative delivery address.
[0035] Data to be acquired/transferred
[0036] The most important information is the correct delivery address with: the post number; last name, optionally first name (if sufficient space available); street and number of the desired PACKSTATION; postal code and city of the desired PACKSTATION; and, the post number entered into the delivery basis by the in-house personnel.
[0037] The examples presented show preferred embodiments of the method for sending postal parcels.
[0038] Thanks to the transition from the first-selected provisional delivery address to the final delivery address, a flexible sending of the postal parcels to the recipient in question can be realized. This also makes it possible for the recipient to designate other persons as the recipient. For example, a customer who is unable to receive a parcel or to pick it up from an electronic parcel compartment system can inform a server that is centrally integrated into the process—preferably a web server—about another person as the recipient by entering identifying information about said person, if possible, in encrypted form. In this manner, another person rather than the originally designated recipient can retrieve a parcel from an electronic parcel compartment system during a prescribed time period without there being a need for the other recipient to know the customer identification information of the first recipient, which is supposed to be kept secret.
[0039] The foregoing description is given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications within the scope of the disclosure may be apparent to those having ordinary skill in the art.
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Disclosed herein is a method for sending postal packets. A provisional destination address is input for distribution of a postal packet, the address capable of being modified after it has been input. An addressee identification code can be allocated to the addressee. The code is capable of being combined with the desired modifiable destination address.
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BACKGROUND OF THE DISCLOSURE
The present invention relates to an apparatus and method of measuring one or more downhole conditions in a well bore, particularly, a battery-powered, positive-pulse-telemetry system for directional survey and steering applications.
In rotary drilling operations, it is very common to measure one or more downhole conditions as drilling progresses. Consequently, various types of directional drilling systems have been developed. Typically, these systems are of the mud-pulse telemetry type for transmitting measurement data to receiving equipment located on the surface. For example, it is quite common to check the inclination and orientation of a well bore. Inclination is the deviation of the well bore from a vertical direction. Orientation refers to the relative rotation of the tool with respect to a selected side of the tool. In addition, it is very common to check the azimuthal direction of the well bore as drilling progresses. Inclination or drift typically has a range of 0 to 90.0 degrees maximum, while tool face orientation and azimuth both have a maximum range of 360.0 degrees.
These variables are measured, encoded and transmitted to the surface via the mud stream. This is accomplished by modulating the mud pressure and sensing the resultant mud pulses at the surface. Various pressure transducers are available for detecting pressure variations in the mud flow at the surface.
It is, therefore, an object of the present invention to provide an improved measuring while drilling system incorporating a battery-powered, positive-pulse-telemetry system.
SUMMARY OF THE INVENTION
The present invention is a measuring while drilling tool which is installed in the drill string. It is located in the drill string near the drill bit and includes conventional pin and box connections. The tool consists of three modules; a mud pulser sub, the electronics module, and the battery module. The assembled tool is located inside a standard non-magnetic collar. The tool includes an axial passage extending therethrough for delivery of drilling mud to the drill bit. The apparatus of the invention includes an elongate plunger located in the mud flow path which is responsive to pressure of the drilling mud. The plunger is forced downwardly in response to pump pressure on the mud, and its downward movement actuates a pair of switches to engage the system for measuring the variables of interest. The plunger passes through a series of constriction rings to form the pressure pulses. Downward movement of the plunger charges a hydraulic system which is solenoid operated to control the duration of the pressure pulses for the encoded signal of interest. The duration of the pressure pulses are displayed at the surface equipment enabling a direct reading of the variable of interest.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are, therefore, not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIGS. 1A-1I, are a detailed, length-wise, sectional view showing the components of the present invention;
FIG. 2 is a sectional view taken along line 2--2 of FIG. 1A showing the mud flow path through the tool of the present invention;
FIG. 3 is a sectional view taken along line 3--3 of FIG. 1B showing a means for aligning the components of the tool;
FIG. 4 is a partial sectional view of the switch housing of the present invention;
FIG. 5 is a sectional view taken along 5--5 of FIG. 4 showing the electrical connectors of the switch housing;
FIG. 6 is a sectional view taken along 6--6 of FIG. 5; and
FIG. 7 is a partial, exploded view showing alignment of the components of the tool of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Attention is first directed to FIG. 1A and FIG. 1B which depict the top part of the preferred embodiment of the measuring while drilling tool. The top part of the tool includes the hollow tubular sub 10. The sub 10 is provided with a box connection 12 at its upper end and a pin connection 14 at its lower end for connection to a standard drill joint 16 shown in dotted lines in the drawings extending downward from the pin connection 14. The tool of the present invention is installed in a drill string which may include thousands of feet of drill pipe. The drill string is suspended from the surface in the well bore and connected to a mud flow line which delivers drilling fluid or mud through the drill string to the drill bit connected to the drill string at the lower end thereof. The measuring while drilling tool is typically located just above the drill bit for measuring the variables of interest, for example, borehole drift.
The sub 10 includes substantial wall thickness to provide adequate strength and an outer diameter which is substantially equal to the outer diameter of the drill string 16. A sleeve 18 is located within the upper portion of the sub 10. The sleeve 18 is axially hollow between a lower threaded end 20 and an upper end defined by an inwardly extending internal shoulder 22. Threadably connected to the lower end of sleeve 18 is a connector assembly including an axially hollow tubular member 24. The member 24 is externally threaded at its upper end for connection to the sleeve 18 at 20. The member 24 further includes an enlarged portion 26 immediately below it threaded end. The enlarged portion 26 provides a circumferential shoulder for engagement with an upwardly facing internal shoulder 28 formed in the sub 10.
The connector assembly includes a collar 32 connected to an axially hollow member 34. The collar 32 is connected to the member 34 by a plurality of radially extending ribs 36 as best shown in FIG. 2. The ribs 36 define fluid passages through the collar 32 permitting drilling fluid to pass through the measuring while drilling tool via an annular passage 37. The lower edge of the collar 32 is formed with a plurality of teeth 38 for cooperative engagement with an adjustment ring 40 which is provided with a plurality of teeth about both ends. The adjustment ring 40 permits slight angular adjustment of the tool so that it may be properly aligned with a sensor package mounted at the lower end of the upper component or module. The adjustment ring 40 includes 36 teeth at its upper end and 37 teeth at its lower end permitting adjustment of approximately 0.25 degrees per tooth.
Pressure surges in the mud flow are formed by a plurality of constriction rings 42 which are securely mounted within the sleeve 18 between the collar 32 and shoulder 22. The constriction rings 42 are streamlined for maximum erosion resistance. Spacer rings 44 and 45 are located above and below the stack of constriction rings 42 insuring that the constriction rings 42 are tightly housed within the sleeve 18. The spacers 44 and 45 are profiled to provide a relatively smooth mud flow transition zone entering and exiting the constriction rings 42. The constriction rings 42 and spacers 44, 45 may be fabricated of any suitable erosion-resistant material; however, in the preferred embodiment, a special grade of tungsten carbide is utilized to form the constriction rings and spacers of the invention.
The sub 10 includes a short slot 30 formed in the interior wall thereof and an oppositely located axial slot 31 formed in the wall thereof. The slot 31 is sized to receive a key 33 integrally formed on the sleeve 24. The key 33 is utilized to align the measuring while drilling tool in a manner to be described in greater detail later herein.
In the drawings, FIG. 1A and FIG. 1B disclose the tubular sub 10 of the apparatus. It will be observed that the various components comprising the tubular sub 10 are very tightly housed therein and O-rings 46 and 48 are provided to form a fluid tight seal with the body of the sub 10. The constriction rings 42 are stacked tightly against each other so that fluid leakage is prevented even under high pressures which may be encountered in the well bore.
Referring now to FIGS. 1A-1C, the mud pulser sub is generally identified by the reference numeral 50. The pulser sub includes a streamlined plug 52 threadably joined to the upper end of a hollow, upstanding tubular member 54. The lower end of the tubular member 54 is externally threaded to receive an internal tubular sleeve 56. The lower end of the tubular member 54 includes an enlarged portion 58 in sealing contact with an outer elongate, axially hollow sleeve 60. The outer sleeve 60 is threadably connected at its upper end to the tubular member 34 and at its lower end to the valve manifold 62. The lower end of the internal tubular member 56 is closed by a plug member 64 which is threadably joined thereto. The plug member 64 includes an axially hollow rod portion 66 depending therefrom. The rod 66 terminates in a head 68 which is reciprocally received within the valve manifold 62. The lower portion of the rod 66 is formed with a plurality of ridges separated by valleys for sequentially contacting the switch mechanism to be described in greater detail later. The ridged portion of the rod 66 is formed by distinct peaks separated by valleys. It is not a threaded portion of the rod 66.
The internal sleeve 56 is concentrically mounted within the external sleeve 60 defining an annular cavity 70 therebetween. The annular cavity 70 is sealed at the upper end by several seals 72 about the enlarged portion 58 of the tubular member 54. The lower end of the annular cavity 72 is closed by the switch housing.
Positioned within the annular cavity 70 is a spring 74 which is compressed between the downwardly facing shoulder 76 of the enlarged portion 58 on the tubular member 54 and the upwardly facing shoulder 78 formed on the switch housing at the lower end of the annular cavity 70.
Referring again to FIG. 1B, it will be observed that a shuttle valve 80 is housed within the internal sleeve 56. The shuttle valve 80 is held in its upper-most position by a spring 82 positioned between the shuttle valve 80 and the plug 64. In its initial position, the shuttle valve 80 engages the downwardly facing edge 84 of the lower end of the tubular member 54, thereby closing the port 86 extending through the internal sleeve 56 and opening to the annular cavity 70. The annular cavity 70 is adapted to receive oil in it at increased pressure. The hollow mud pulser sub 50 defines a central cavity 88 which is in fluid communication with the low pressure cavity 90 in the valve manifold 62.
Referring now to FIGS. 1C and 1D, the valve manifold 62 is shown in greater detail. The valve manifold comprises a tubular body 62 threadably connected at its upper end to the external sleeve 60 and threadably connected at its lower end to the oil reservoir housing 92. The microswitch housing, generally identified by the reference numeral 94, is mounted to the upper end of the valve manifold body 62 as best shown in FIG. 4. The switch housing 94 compreses a substantially cylindrical member including an axial passage 96 extending therethrough. The axial passage 96 is defined by a slotted cylindrical wall 98 terminating at its lower end in a circumferential flange 100. A pair of bolts 102 extend through the flange 100 for threadably securing the switch housing 94 to the upper end of the valve manifold body 62.
Referring again to FIG. 1C, it will be observed that the switch housing 94 houses two oppositely facing switches which engage the ridged portion of the rod 66 as it advances downwardly through the switch housing. The switch 104 is contacted first as the rod 66 moves downward. The switch 104 is the on/off switch which turns on the electrical system and initializes the tool for operation. The switch 104 is provided with a wide contact area so that it bridges the ridges of the rod 66 and remains on during the operation of the tool. The switch 106 switches on/off as the rod 66 advances downward. As the pulsar component 50 moves downward, oil in the annular cavity 70 is pressurized and forced through the switch housing 94. High pressure oil passes through the axial passage 96 and out the crescent opening 97 and is directed through a restrictor valve 108. The restrictor valve 108 permits the high pressure oil to flow smoothly out of the annular cavity 70. A high pressure passage 110 extends from the restrictor 108 to the solenoid 112. A one-way check valve 114 incorporated in the low pressure fluid path prevents high pressure fluid from exiting the switch housing to the low pressure passage 116. The solenoid valve 112 is electrically connected to the switch housing 94 and to the sensor module. For the sake of clarity in the drawings, the electrical wires are not shown. However, referring now to FIG. 6, electrical connectors 118 are shown threadably mounted to the valve manifold housing 62. The connectors may be of any suitable type, as for example, KEMLON connectors.
Attention is now directed to FIG. 1D and FIG. 1E, wherein the oil reservoir housing 92 is shown in greater detail. The housing 92 includes a central oil cavity 120 defined by a cylindrical tube 122. The cylindrical tube 122 is externally threaded at its upper end to be received by a mounting ring 124 and is externally threaded at its lower end to be received by a mounting ring 126. The tube 122 is completely enclosed by a flexible bladder 128 which is securely mounted at each end to the rings 124 and 126. The tube 122 and bladder 128 define an annular cavity 130 therebetween. Fluid communication is established between the interior of the tube 122 and the cavity 130 via a port 132 extending through the tube 122.
The tube 122 and bladder 128 are held in a fixed relationship within the reservoir housing 92. The tube 122 and bladder 128 are concentrically positioned within the housing 92 so that an annular space 134 is also defined between the bladder 128 and the surrounding housing 92. The annular cavity 134 is open to drilling fluid pressure via the ports 136 and 138 located at the upper and lower ends of the housing 92. Drilling fluid enters the upper end of the annular cavity 134 via the ports 136 and exits at the lower end thereof via the ports 138. Thus, the internal pressure of the tool is maintained at the mud flow pressure in the borehole.
The lower end of the housing 92 is closed by a connector 140. The connector 140 houses the electrical connectors 142 and wires extending from the switch housing 94 for connection to the sensor module. The electrical connectors 142 are insulated so that they will not be contaminated by the oil in the internal cavity 120. The lower end of the connector 140 is defined by a socket-type recess for receiving a prong-type band connector (shown in dotted line in FIG. 1E).
To this point, the upper portion of the measuring while drilling tool of the present invention has been described. It is understood that all connectors have been made up tight and all fluid cavities have been sealed by seals to prevent leakage. To enable proper alignment of the three modules making up the tool of the invention, the lower end of the connector 140 incorporates a downwardly extending semicircular neck 144. The neck 144 includes a flat surface 146. The stabilizer component 148 is provided with a matching neck 150 and flat cooperating surface 152 thereon, as best shown in FIG. 7. The two components are joined together by a tubular connector 154 which is provided with left hand threads at one end and right hand threads at the other so that both components are drawn towards each other until they are completely made up as shown in FIG. 1E.
Referring again to FIG. 7, it will be observed that the stabilizer component 148 is a machined one piece component which is provided with a second semicircular neck 156 extending from the lower end thereof. The neck 156 is provided with a flat surface 158 which lies in a plane parallel to the flat surfaces 146 and 152. Once all connections in the upper portion of the tool are tightly made, the flat surface 158 may be aligned to lie in a plane parallel to the plane of the key 33. This is accomplished by rotating the collar 32 and thereby the stabilizer 148 to visually align the surface 158 with the key 33. Fine adjustment is then made by rotating the adjustment ring 40 so that the key 33 and the flat surface 58 are in substantial alignment. Once aligned in this manner, the sensor package housing 160 is bolted to the neck 156 of the stabilizer 148. The sensor package housing is provided with a mating neck 162 insuring that the sensor package will be properly aligned with the upper portion of the tool. An external V-grooved slot 163 on the tubular member 10 in substantial alignment with the key 33 provides a visual indication of the orientation of the sensor module insuring that it is properly oriented.
Referring now to FIG. 1F, the stabilizer 148 is shown. The stabilizer 148 includes an axial passage 164 permitting the electrical connectors to be extended to the sensor module housing 160. The stabilizer 148 includes a shoe 166 which is securely fixed thereon by bolts 168. Opposite the shoe 166, the stabilizer 148 incorporates a hydrostatic lock including a piston exposed to borehole pressure at the piston surface 170. The other end of the piston rod 172 is connected to a wedge member 174 which is forced outwardly upon an increase in pressure, thereby tightly securing the measuring while drilling tool to the surrounding drill pipe 16.
The sensor package of the tool of the invention is housed within the sensor housing 160. The sensor housing 160 is internally threaded at the upper end to receive the externally threaded end of the stabilizer body 148 and is internally threaded at its lower end to receive the externally threaded end of the operating mode module generally indentified by the reference numeral 180. The sensor package of the tool of the present invention is of a type commercially available which may be encoded to transmit the value of the downhole variables of interest.
The operating mode module 180 is threaded to the lower end of the sensor package housing at 182, as best shown in FIG. 1G. The module 180 is provided with a plug-type connector received in a socket receptacle in the lower end of the sensor package housing 160. A spring 184 aids in maintaining the connection, even under extreme loads. KEMLON connectors 186 are incorporated in the module 180, the electrical wires extending therethrough to the selectable switches 188 and 190. The switches 188 and 190 are protected from the drilling fluid by externally threaded plugs which are received in the internally threaded ports 192 and 194. The switches 188 and 190 are selectively set prior to placing the tool in the borehole. The switches 188 and 190 are four position switches and may be set for a selected mode or time interval, as for example, the survey mode or steering mode. The switch 190 may be set for a specific data rate to minimize the effects of pulse attenuation as depth increases. The switch 196 permits the tool to be connected to a test unit for a quick operations check before running the tool in the borehole. The check verifies that the system is at full operating capability. This middle portion of the tool is firmly fixed in the drill pipe 16 by incorporating a second shoe 198 and hydrostatic lock 200 to lock the tool to the drill pipe.
The lower third of the tool comprises a battery package housed within a tubular housing 202. The tubular housing 202 is threadable secured at its upper end to the lower end of the operating mode module 180 and at its lower end to a bottom located stabilizer 204. The battery package of the tool is electrically connected to the sensor package via a prong and socket connection shown at 206. A spring 208 insures that the electrical connection is maintained in the violent environment near the drill bit. An elastomeric pad 210 located at the lower end of the battery package functions as a shock absorber to reduce the risk of damage to the battery package.
In operation, the measuring while drilling tool of the present invention is incorporated in a drill string near the drill bit. The tool is equipped with a sensor package which forms electrical output signals to operate a solenoid valve and thereby cause pressure fluctuations in the mud stream which may be measured by surface equipment. The solenoid valve is operated for a sufficient time to give the proper value of the variable of interest. In the present disclosure, this is accomplished by forcing the mud pulser sub 50 through a series of constriction rings 42 to create the mud flow pressure pulses.
Initially, the tool is initialized by shutting down the mud pumps for a short period of time, perhaps 20 seconds. The mud pumps are then actuated to overcome the upward force of the spring 74 and the resistance of the oil in the annular cavity 70. A quick jolt enables the pulser sub 50 to drop slightly by forcing the shuttle valve 80 downward to open the port 86 and thereby permit high pressure oil to enter the small cavity 212 shown in FIG. 1B. Upon downward movement of the pulser sub 50, the switch 104 is engaged and the electronic system of the tool is turned on an initialized. The mode of operation of the tool has been preselected so that once the tool is turned on, the sensor package operates the solenoid valve in the operational sequence to display the value of the variable of interest at the surface.
The surface equipment measures the time duration of the pressure pulses in the mud. The pulser sub 50 advances downward through a complete sequence so that the plug 52 passes through all of the constriction rings 42. All data is transmitted to the surface equipment twice for verification purposes. Initially, a calibration time is transmitted. Thereafter, the value of the desired variable is transmitted as series of integers. For example, in the survey mode, the tool will transmit three integers for drift and three integers for azimuth. The drift will be transmitted in tens, units, and tenths. For example, if the drift is 32.4 degrees, the first integer to appear is a "3", the second is a "2" and the third is a "4". Azimuth will appear as hundreds, tens and units. For example, 125 degrees would appear first as "1", second as "2", and third as "5". The measurement parameters of the system for drift is 0 to 90 degrees and for azimuth is 0 to 360 degrees. The data is transmitted twice for verification and to insure the highest degree of accuracy. The last signal that may be transmitted is any other variable of interest as, for example, battery status, temperature or other measurable downhole variable.
In the operational sequence, as the pulser sub 50 is forced downward, the spring 74 is compressed and fluid in the annular cavity 74 is compressed and forced through the restrictor 108 as the enlarged portion 58 of the tubular member 54 is forced downward. The solenoid 112 operated by the sensor module permits the pulser sub 50 to descend at an appropriate rate to create the pressure pulse duration required for encoding the value of the measured variable. The switch 104 is on during the entire sequence, whereas the switch 106 traces the peaks and valleys of the rod 66. The peaks and valleys on the rod 66 correspond to the peaks and valleys of the constriction rings 42 enabling the sensor package to transmit the correct integer in the three digit transmission which makes up the variable of interest. At the end of the transmission sequence, the mud pumps are turned off permitting the pulser sub 50 to rise upon return of the spring 74 to its original position. As the sub 50 rises, oil is permitted into the annular cavity 70 via the check valve 114. The upward travel of the sub 50 is limited upon engagement of the shoulder 55, which is integrally formed on the tubular member 54 with the downwardly facing shoulder 35 on the tubular member 34. The transmission time is calculate as a function of T=T 1 +NT 2 , wherein T 1 equals calibration time (seconds), T 2 equals seconds (integer), and N equals an integer. T 1 is calibrated at the beginning of a sequence and T 2 is selected by setting the switch 190 prior to lowering the tool into the borehole. Therefore, the apparatus of the invention provides a direct reading of N so that a direct number transfer of the value of the sought variable is transmitted to the surface equipment.
While the foregoing is directed to the preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims which follow.
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A measuring while drilling tool is disclosed. The preferred embodiment incorporates an outer tubular member adapted to be connected in a drill string above the drill bit. The apparatus utilizes a mud pulser sub extending through the hollow tubular member and anchored in the drill string. The apparatus includes a sensor module and a battery module operatively connected to form a single tool. The apparatus utilizes mud flow pressure in the drill string to move a mud pulser sub through constriction rings for creating a sequence of mud pulses detectable by surface located receiving means.
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FIELD OF THE INVENTION
The present invention relates to a device for balancing a rotating body during rotation.
BACKGROUND
As an example of such a body there may be mentioned, above all, the rotors of large machines, for example turbo-machines or electric machines. Such rotors are usually balanced first of all in the manufacture and thereafter in connection with the erection at the place where the machine is to be used, and then in both cases normally by means of weight balancing, correction balances being placed at appropriate places. This procedure is time-consuming and expensive and does not always lead to a satisfactory result in the case of machines with great susceptibility to unbalance. This is true in particular if the unbalance is due in a minor degree on a real mass unbalance, but more to a deformation of the rotor, in which case weight balancing often does not give good results. In addition, the rotor may change with time, and also the pressure on the rotor may cause a change in balance.
The art also evidences devices to selectively cut away small portions of the rotating body so as to counteract unbalance. See U.S. Pat. No. 3,499,136 and corresponding thereto U.K. Pat. No. 1,178,337.
To be able to satisfy high demands on the balance of a rotary machine it would therefore be desirable to be able to perform an after-balancing of the rotor during operation, and according to the invention a device for this purpose is proposed according to the appending claims.
SUMMARY OF THE INVENTION
The invention is based on an unsymmetrical, local heating of the rotor, which is to be bent as a result of the heating so that the unbalance is counteracted. More particularly, the phase and magnitude of any unbalance is detected and an energy source supplies energy pulses to the rotating body for local asymmetric heating to cause thermal deformation of the axis of the body without removing or adding material from or to the body.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in more detail with reference to the accompanying drawings, in which FIG. 1 shows a machine with a device according to the invention,
FIG. 2 showing a detail of FIG. 1,
FIG. 3 shows a diagram of the vibration of the rotor and the energy pulses fed to the rotor, and
FIG. 4 shows the device according to the invention applied to a more complicated machine plant.
DETAILED DESCRIPTION
FIG. 1 shows a rotary machine with rotor 1, a shaft 2 and bearings 3, the stator of the machine being omitted for the sake of simplicity. For indication of a possible unbalance in the rotor in operation there are arranged sensing members 4 which, as shown, may be inductive or electro-magnetic transducers sensing the variation in the distance between the shaft 2 and the members 4, as indicated in FIG. 3.
Instead of electro-magnetic transducers it is possible to use capacitive transducers or optical transducers which may operate, for example, according to the echo method by means of light pulses reflected from the surface of the shaft. Instead of sensing the deflection of the shaft it would be possible to build in pressure-sensitive transducers in the bearings 3 or in connection with the oil film of the bearings. There are different types of such transducers to choose from depending on what signal processing is preferred. The essential point is that transducers are used which are able to emit distinct signals in clear synchronism with the rotor and with a magnitude which reflects the degree of the unbalance.
In order to compensate for the unbalance, according to the invention, the rotor is asymmetrically heated at appropriate places while in operation, which thus means that the rotor is to be supplied with energy pulses synchronously with the rotation so that the asymmetric heating causes a deformation which counteracts the unbalance. To achieve such an asymmetric heating it is necessary to have an energy source capable of conveying distinct pulses with a sufficiently high energy and with a short duration synchronously with the rotation of the rotor.
As such an energy source there may be used a high-frequency generator 5 which is controlled by a control device 7 and feeds energy pulses through a coil 6 to pre-selected places on the shaft 2. The location and construction of the high-frequency coils 6 depend partly on how the shaft and the rotor may be expected to become deformed at the operating speed, partly on where it will be possible to place the coils, and also on how the rotor or the shaft can be affected by the heat influence. This, in turn, may depend on whether the rotor or the shaft is ferromagnetic, electrically conducting or electrically insulating. The drawings, which show the coils 6 adjacent shaft 2 are intended to generally depict heating of the rotating body. Thus the invention contemplates heating either the rotor 1, shaft 2, or both.
FIG. 2 shows in axial section how the member 4 and the coil 6 can be located in relation to the shaft 2. FIGS. 1 and 2 further indicate an angle reference system 9, 10, comprising a marking point 9, for example a boss on, or a hole in, the shaft 2 and a sensing member 10 which may be of the same type as the member 4. The signals from the members 4 and 10 are supplied to a signal transducer 8 for the control device 7, the energy pulses thus being supplied to the coil 6 with a correct phase position in relation to rotation of the rotor.
Thus the transducer 8 may well include a transducer per se to convert the output of members 4 and 10 to suitable electrical signals, a pulse shaper and a delay circuit as shown, for example in U.K. Pat. No. 1,178,337. The delay may be manually adjustable, as shown in the referenced patent. In addition, a divider may optionally be included, as mentioned below. The control device 7 can be implemented in the form of a switch to start or stop the generator 5 at appropriate times, or to control the phase and amplitude of the output of generator 5 both as shown in FIG. 3.
To attain the asymmetric heating, the energy pulses are controlled in time with the rotation of the rotor. This can be done either by amplitude modulation or by pulse modulation, which are both shown in FIG. 3. The first line in FIG. 3 indicates the signal p4 from the member 4, i.e., the variation of the unbalance. The second line indicates the pulses p10 from the member 10, the phase position θ of the amplitude of the unbalance thus being defined. Through the angle θ and the angle between the member 4 and the coil 6, the desired phase position φ of the energy pulses can be determined. Often it may be desirable to make a manual adjustment of φ within a precalculated range in order to achieve an exact balance. The degree of asymmetrical supply of heat is then determined by the amplitude A of the modulation or the duration α of the pulse, respectively, as indicated in lines 3 and 4 of FIG. 3. The values of A and α as well as φ are controlled by means of the control device 7. A, α, and φ are selected based on the amplitude δ and phase angle θ of the vibrations. How the relations between A, α and δ and φ and θ are to be chosen may in exceptional cases be determined by a theoretical analysis, but must in general be determined by tests.
Generally the heating should be applied to an area centered 180° out of phase with the unbalance. However, to determine φ it is also necessary to take into account the time constants of the circuits and the thermal transmission characteristics of the heating system.
If, during heating, θ changes, the phase angle φ should be altered in the opposite sense, by an equal amount. If, on the other hand, θ does not change, then φ should also remain constant, if δ is reduced by the application of heat. If δ grows then φ must be changed 180°. In either event α or A should be maintained or increased until δ is reduced to zero.
Where the control pulses take the form shown in the fourth line of FIG. 3, the frequency of the pulses may be the same as that of the signal pulses, i.e., p4 or a sub-multiple thereof. In the latter instance, heat would only be applied 1 out of n revolutions where the frequency of the control pulses was 1/n the frequency of the signal pulses. This can be implemented by using a 1/n divider in the control device 7.
Instead of a high-frequency generator as the energy source, it would be possible to have any energy source which is able to supply controlled, energy-rich pulses with the desired frequency and phase position. As a very simple energy source, particularly at lower speeds of rotation, it would be possible to use a welding torch controlled by a rotating or oscillating diaphragm. As one further extremity a laser beam might be used, which is able to fulfill the highest demands both with regard to energy and controllability.
In principle, the phase position of the energy pulses over the coils 6 could be determined directly in relation to the signals from the members 4, in which case the reference system 9, 10 could be omitted. However, the purpose of the arrangement according to the invention is to balance out the vibrations completely so that the signals from members 4 fall away. Then in order to maintain the balance, the phase position and magnitude of the energy pulses must be secured by providing the transducer 8 with some kind of memory device which records the original phase position θ of the signals from member 4 in relation to the reference system 9, 10. For this reason, and possibly also to be able to point out the phase position of the unbalance after stopping, the reference system 9, 10 is desirable. In FIGS. 1 and 2 there are indicated connections for transmitting signals from transducer 8 to control device 7. It is within the scope of the invention to employ manually made connections between transducer 8 and control device 7 so that, for example, balancing in the proper sense is assured when a newly installed plant is started up for the first time.
FIG. 4 shows as an example a more complicated machine plant comprising the connected rotors for a high-pressure turbine HT, a number of low-pressure turbines LT and a generator G. In such a case there are a great number of bearings 3, and therefore the unbalance must be measured by members 4 in so many places as are required to have a desirable survey of any unbalance. Furthermore, heating coils 6 or similar energy pulse devices must be located at such places where a local heating may provide a desired compensation for the unbalance. To achieve a correct signal processing, the signal transducer 8' in such a case should be constructed as a programmed arithmetic unit of a minicomputer type or the like, so that the control device 7' is able to achieve proper distribution of the energy pulses from the high-frequency generator 5'.
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A balancing device and method for balancing a rotating body during operation. The device and method detects the phase and amount of unbalance and provides signals in synchronism with the unbalance. Local heating of the rotating body is provided to counteract the unbalance by thermal deformation of the axis of the body without removing material. The phase and amount of the local heating are controlled in relation to unbalance detected.
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This application is a 371 of PCT/ES95/00001 filed Jan. 4, 1995.
The present invention relates to novel Polymorphs B and C of 1- 2,4-dichloro-β- (7-chlorobenzo b!thien-3-yl)methoxy!phenethyl!imidazole mononitrate-compound known as sertaconazole mononitrate (WHO).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an infrared (IR) spectrum of sertaconazole mononitrate Polymorph B.
FIG. 2 is a differential scanning calorimetry (DSC) thermogram of sertaconazole mononitrate Polymorph B.
FIG. 3 is an X-ray powder diffractogram of sertaconazole mononitrate Polymorph B.
FIG. 4 is an infrared (IR) spectrum of sertaconazole mononitrate Polymorph C.
FIG. 5 is a differential scanning calorimetry (DSC) thermogram of sertaconazole mononitrate of Polymorph C.
FIG. 6 is an X-ray powder diffractogram of sertaconazole mononitrate Polymorph C.
FIG. 7 is an infrared (IR) spectrum of sertaconazole mononitrate Polymorph A.
FIG. 8 is a differential scanning calorimetry (DSC) of sertaconazole mononitrate Polymorph A.
FIG. 9 is an X-ray diffractogram of sertaconazole mononitrate Polymorph A.
DETAILED DESCRIPTION OF THE INVENTION
1- 2,4-Dichloro-β- (7-chlorobenzo b!thien-3-yl)methoxy!phenethyl!imidazole mononitrate is used in therapeutics as an antifungal agent. The preparation of this compound was disclosed in European Patent No. 0151477. The applicants have found out that sertaconazole mononitrate exhibits two novel polymorphs, B and C, which have a melting point in the range of 163-164° C. and 164.5-165.5° C. respectively. The present invention provides a process for obtaining selectively each polymorph B and C of sertaconazole mononitrate. In the aforesaid patent, sertaconazole mononitrate, which will be hereinafter referred as Polymorph A, was obtained with a melting point of 156-157° C. The applicants have found out in the course of different crystallization assays that when polymorph A is recrystallized from absolute ethanol, it yields the new polymorph B, and when polymorph A is recrystallized from chloroform, it yields the new polymorph C. The melting points of the three polymorphs are within a close range, but they are well differentiated by means of the enclosed IR spectra, DSC thermograms and X-ray powder diffractograms. FIGS. 7, 8 and 9 concerning Polymorph A are enclosed in order to support the differences between the new polymorphs B or C and primary polymorph A.
The physical properties of polymorphs B and C of sertaconazole mononitrate are different from those of primary polymorph A. In effect, polymorph B shows higher stability than that of polymorph A versus a moderate supply of external energy (such as sifting and homogenizing processes) and is, therefore, suitable for the preparation of topical dosage solid forms, such as a powder. Polymorph C is assumed to be even more stable than polymorph B versus an external energetic supply and can, therefore, be conveniently used in processes requiring a higher energetic supply, such as compression processes, thus being suitable for the preparation of tablets. In case of liquid formulations, either polymolph, B or C, can be used since the proper characteristics of a solid disappear in a solution.
In addition to the aforesaid pharmaceutical forms, polymorphs B and C of sertaconazole mononitrate mixed with pharmaceutically acceptable carriers can be administered by the oral route to humans and animals in the form of capsules, syrups, solutions, powder, etc., by an injectable route, by a rectal route, and by a vaginal-intrauterine route in the form of ovulum, ointment, cream, pessary, lotion, etc., at daily doses ranging from 100 to 800 mg; and by a topical route in the form of a cream, lotion, ointment, emulsion, solution, shampoo, gel, etc., at concentrations ranging from 0.1 to 5%.
Also polymorphs B and C of sertaconazole mononitrate in admixture with a diluent or carrier and in suspension with irrigation water can be used against crop diseases; they can also be applied by atomizing, spraying, dusting, or in the form of cream, paste, etc., at the rate of 0.1-15 kg per hectare of soil.
The following examples will illustrate the preparation of polymorphs B and C of sertaconazole mononitrate, and pharmaceutical formulations containing them. The examples are not intended to limit the scope of the invention as defined hereinabove or as claimed below.
EXAMPLE 1
Polymorph B of 1- 2,4-dichloro-β- (7-chlorobenzo b!thien-3yl)methoxy!phenethyl!imidazole mononitrate (Sertaconazole mononitrate polymorph B)
10 g of sertaconazole mononitrate (polymorph A) are dissolved in 100 ml of absolute ethanol at reflux. The hot solution is filtered and allowed to crystallize at room temperature without stirring. The crystalline solid formed is filtered and dried to give 8.78 g of Polymorph B of 1- 2,4-dichloro-β- (7-chlorobenzo b!thien-3-yl), methoxy!phenethyl!imidazole mononitrate (Sertaconazol mononitrate polymorph B).
Melting point: 163-164° C.
IR spectrum (KBr): FIG. 1
DSC thermogram: FIG. 2
X-ray diffractogram: FIG. 3
EXAMPLE 2
Polymorph C of 1- 2,4-dichloro-β- (7-chlorobenzo b!thien-3-yl)methoxy!phenethyl!imidazole mononitrate (Sertaconazol mononitrate polymorph C)
5 g of sertaconazole mononitrate (polymorph A) are dissolved in 150 ml of chloroform at reflux. The hot solution is filtered and allowed to crystallize at room temperature without stirring. The crystalline solid formed is filtered and dried to give 4.2 g of Polymorph C of 1- 2,4-dichloro-β- (7-chlorobenzo b!thien-3-yl), methoxy!phenethyl!imidazole mononitrate (Sertaconazol mononitrate polymorph C).
Melting point: 164.5-165.5° C.
IR spectrum (KBr): FIG. 4
DSC thermogram: FIG. 5
X-ray diffractogram: FIG. 6
EXAMPLE 3
______________________________________2% powder for topical applicationComposition for 100 g:______________________________________Sertaconazole mononitrate polymorph B 2 gTitanium dioxide 10 gKaolin 10 gTalc 78 g______________________________________
EXAMPLE 4
______________________________________Vaginal tabletsComposition for 1 vaginal tablet:______________________________________Sertaconazole mononitrate polymorph C 500 mgCorn starch 90 mgAerosil 200 1 mgPrimogel 45 mgCompritol 150 mgMagnesium stearate 7.5 mgAvicel PH-101 to volume 1100 mg______________________________________
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Two polymorphs of 1- 2,4-dichloro-β- (7-chloro-benzo b!thien-3-yl)methoxy!phenetyl!imidazole mononitrate have been identified. A process for the preparation thereof and composition are described.
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BACKGROUND
1. Description of the Related Art
The present invention relates generally to circuitry. More particularly, it relates to an input buffer circuit capable of buffering signals that comply with any one of multiple I/O standards (e.g. LVDS, SSTL and HSTL).
Many integrated circuits support a variety of differential and single-ended I/O standards and interface with backplane, processors, busses, and memory devices, among other things. Some of these standards include LVDS, SSTL and HSTL. LVDS (Low Voltage Differential Signaling), LVPECL (low-voltage positive emitter-coupled logic), and CML (current-mode logic) are commonly used differential I/O standards in high-speed systems. These differential I/O standards are commonly used because they have higher performance, better noise margins, lower electromagnetic interference (EMI), and lower power consumption. LVDS for example, is a low noise, low power and high speed I/O interface. LVDS uses differential signals without a reference voltage. An LVDS buffer has two input signals and the voltage difference between the two signals defines the logic state of the LVDS signal at any one time.
Differential SSTL (Stub Series Terminated Logic) is a memory bus standard used for applications such as high-speed double data rate (DDR) SDRAM interfaces. The differential SSTL I/O standard is similar to voltage referenced SSTL and requires two differential inputs with an external termination voltage. In other words, unlike the LVDS, the SSTL input threshold is defined by an external reference voltage.
Known integrated circuits that support various differential I/O standards have a different I/O buffer for each of these standards. For example, two dedicated input buffers are used to accommodate LVDS and SSTL signals in a device. However, having a dedicated buffer for each I/O standard takes up space and this has increasingly become a dominant factor in digital designs as ICs become smaller and smaller.
Using one buffer for multiple I/O standards instead of using a dedicated buffer for each I/O standard saves space on the device. Using one buffer for multiple I/O standards can also potentially increase the overall efficiency of ICs. For example, the resulting netlist of a PLD, with fewer buffers, will be less complex compared to a netlist with more buffers.
Therefore, it is desirable to use a single buffer for multiple differential I/O standards instead of a dedicated buffer for each of these standards. It is also desirable to have a simpler input buffer circuit to save die space.
SUMMARY
Embodiments of the present invention include circuits and techniques for using an input buffer for multiple differential I/O standards.
It should be appreciated that the present invention can be implemented in numerous ways, such as an apparatus, a method or a circuit. Several inventive embodiments of the present invention are described below.
In one embodiment, an input buffer circuit is disclosed. This input buffer circuit has an input buffer with two input terminals. The first input terminal receives a first signal and the second input terminal receives a second signal from a switch. The switch in this buffer circuit is used to select between two different signals. In some embodiments, the switch selects between an inverted version of the first signal and a third signal and transmits the selected signal to the second input terminal of the input buffer.
In another embodiment of the present invention, a method of buffering two types of differential signals with one input buffer is disclosed. The method includes using a first signal as a first input to the one input buffer. The method further includes using a second signal as a second input to the one input buffer when buffering a first type of differential signal. A third signal is used as the second input to the one input buffer when buffering a second type of differential signal. In some embodiments, the first type of differential signal is consistent with the LVDS I/O standard. In other embodiments, the second type of differential signal is consistent with the SSTL or HSTL I/O standard.
In yet another embodiment in accordance with the present invention, a buffer circuit is disclosed. The buffer circuit has a differential amplifier with two input terminals. The first input terminal of the differential amplifier receives a first signal. A switch with a plurality of input terminals is coupled to the second input terminal of the differential amplifier. The switch selects and transmits one of the signals to the second input terminal of the differential amplifier. A logic gate is coupled to the enable terminal of the differential amplifier and the enable terminal of an input buffer. The output of the logic gate selectively enables and disables the differential amplifier and the input buffer. When the differential amplifier is disabled, the input buffer transmits the first signal as an output of the buffer circuit. When the input buffer is disabled, the differential amplifier transmits and outputs a differential signal as the output of the buffer circuit.
Other aspects of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 , as an illustrative example, shows a simplified circuit with three dedicated buffers—SSTL/HSTL, LVDS, and TTL.
FIG. 2 shows a simplified circuit block diagram of a switch coupled to an input buffer in accordance with an embodiment of the present invention.
FIG. 3 , meant to be illustrative and not limiting, shows a switch and a logic gate coupled to a differential amplifier and a buffer in accordance with another embodiment of the present invention.
FIG. 4 , meant to be illustrative and not limiting, shows a differential buffer coupled to two switches in accordance with an embodiment of the present invention.
FIG. 5 , meant to be illustrative and not limiting, shows a process flow to buffer two types of differential signals using a single input buffer in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
The following embodiments describe circuits and techniques for utilizing one input buffer for multiple I/O standards.
It will be obvious, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well-known operations have not been described in detail in order not to unnecessarily obscure the present invention. Embodiments described herein provide techniques for using one single buffer for multiple differential I/O standards.
FIG. 1 , as an illustrative example, shows a simplified circuit with three dedicated buffers—SSTL/HSTL, LVDS and TTL. Any number of buffers can be used even though only a few are shown in FIG. 1 . As shown in FIG. 1 , the SSTL/HSTL buffer 100 has three input terminals. An enable signal is fed into the enable input terminal 102 of the SSTL/HSTL buffer 100 . The SSTL/HSTL buffer 100 also has two other input terminals. The first input terminal 110 receives a reference voltage, VREF. The reference voltage used is generally between 1.0V to 3.0V. A second input terminal 120 receives a user input signal. The voltage difference between the first and second input terminals 110 and 120 defines the logic state of the SSTL/HSTL signal.
A dedicated LVDS input buffer 150 is also shown in FIG. 1 . This buffer also has three input terminals. The LVDS buffer 150 receives an enable signal with the enable input terminal 152 . The first input terminal 154 , receives a user input signal, just like the SSTL input terminal 120 . However, instead of a reference voltage, the second LVDS input terminal 156 receives a second signal which is an inverted version of the first signal 154 . The LVDS buffer 150 outputs a differential signal when enabled.
When both the SSTL/HSTL 100 and LVDS 150 buffers are not enabled, a third buffer, the TTL (Transistor-Transistor Logic) buffer 170 is enabled. The TTL buffer 170 has an enable terminal 172 and an input terminal 174 . The AND gate 160 selectively enables the TTL buffer 170 when both the SSTL/HSTL buffer 100 and the LVDS buffer 150 are disabled. Inverters 115 are used to invert the enable signals for buffers 100 and 150 going into the AND gate 160 . The input terminal 174 of the input buffer 170 receives the same input as the input terminals 110 and 154 of the SSTL/HSTL buffer and the LVDS buffer respectively. The output of the buffers 100 , 150 and 170 are coupled together as a single output 199 . At any one time, one of the buffers 100 , 150 or 170 will be enabled and the output 199 will carry the output of that buffer.
FIG. 2 shows a simplified circuit block diagram of a switch coupled to an input buffer in accordance with an embodiment of the present invention. A buffer 220 is used to support different types of differential I/O standards. In some embodiments, the buffer 220 acts as an LVDS input buffer. In other embodiments, the buffer 220 is a differential HSTL or differential SSTL input buffer. A first input terminal 212 of the buffer 220 receives an input signal. The input signal received by the input terminal 212 may be a user input signal. A logic gate 230 with two input terminals is coupled to the enable terminal of the buffer 220 . The logic gate 230 enables and disables the buffer 220 based on the inputs received by input terminal 232 and input terminal 234 of the logic gate 230 . In some embodiments, if one of the input terminals 232 or 234 receives a high signal, the buffer 220 will be enabled, and if both terminals 232 and 234 receive a low signal, the buffer 220 will be disabled. Therefore, even though an OR gate 230 is shown in FIG. 2 , one skilled in the art should appreciate that an XOR gate could also be used.
A switch 200 is coupled to a second input terminal 214 of the buffer 220 . In certain embodiments, the input terminal 202 of the switch receives the inverted version of the signal received by the input terminal 212 , and the input terminal 204 receives a reference voltage in the range of 1.0V-2.5V. The switch 200 can be programmed to transmit the first signal received by the first input terminal 202 or the second signal received by the second input terminal 204 . The switch selects the first signal as the second input 214 to the buffer 220 when buffering an LVDS signal and selects the second signal as the second input 214 to the buffer 220 when buffering a differential SSTL or HSTL signal. In some embodiments, the switch 200 is a one-time-programmable switch. In other embodiments, the switch 200 is a reprogrammable switch.
The switch 200 selects between two inputs. In some embodiments, the switch makes a selection based on the inputs of the logic gate 230 . As an example embodiment, the input terminal 232 of the logic gate 230 may receive an LVDS enable signal and the input terminal 234 of the logic gate 230 may receive an SSTL or HSTL enable signal. Based on this example, the switch will select the first signal received by the input terminal 202 when the LVDS enable signal at the input terminal 232 is a logic ‘1’. Similarly, the switch will select the second signal received by the input terminal 204 when the SSTL or HSTL enable signal at the input terminal 234 is a logic ‘1’. Thus, in some embodiments, the selection of the switch 200 is based on the inputs 232 and 234 of the logic gate 230 and is consistent with the selected type of differential signal. The output 222 of the buffer 220 will carry the appropriate output signal based on the selected type of differential signal. The circuit as shown in FIG. 2 can also be integrated into an IC and the first signal received by the first input terminal 212 of the buffer 220 may come from a pin on the IC.
FIG. 3 , meant to be illustrative and not limiting, shows a switch 320 and a logic gate 340 coupled to a differential amplifier 300 and a buffer 360 in accordance with another embodiment of the present invention. The first input terminal 302 receives an input signal IN. The IN signal may originate from a source external to the circuit. The second input terminal 304 of the differential amplifier 300 is coupled to a switch 320 . The switch 320 receives a plurality of signals and selectively transmits one of the signals to the second input terminal 304 . In certain embodiments, the switch 320 has two input terminals and selects between two different signals as shown in FIG. 3 . The first input terminal 322 of the switch 320 receives an inverted version INA of the input signal IN. The second input terminal 324 of the switch 320 receives a reference voltage VREF. In some embodiments, the reference voltage is between 1.2 Vccn to 2.5 Vccn. When the differential amplifier 300 is transmitting an LVDS differential signal, the switch will select and transmit the INA signal from the first input terminal 322 of the switch 320 to the second input terminal 304 of the differential amplifier 300 . Accordingly, when the differential amplifier 300 is transmitting an SSTL or HSTL differential signal, the switch will select and transmit the reference voltage from the second input terminal 324 of the switch 320 to the second input terminal 304 of the differential amplifier 300 .
A logic gate 340 is also coupled to an enable terminal 308 of the differential amplifier 300 . As shown in FIG. 3 , a two-input OR gate 340 receives two enable signals (e.g., LVDSIE and SSTLIE) with two input terminals 342 and 344 to selectively enable the differential amplifier 300 . Table 1 below shows the output of the OR gate 340 based on the inputs to input terminals 342 and 344 . When both the inputs to input terminals 342 and 344 are disabled, the differential amplifier 300 is disabled. In some embodiments, both the inputs to input terminals 342 and 344 are disabled when they receive a ‘0’ as an input, as shown in Table 1. When, in the embodiment illustrated in Table 1, the LVDSIE signal is set to high (i.e. when LVDSIE is a ‘1’), then the differential amplifier 300 is enabled and the switch 320 selects the inverted version INA 322 as the second input 304 to the differential amplifier 300 . When, in the embodiment illustrated in Table 1, the SSTLIE signal is set to high (i.e. when SSTLIE is a ‘1’), then the differential amplifier 300 is enabled and the switch 320 selects the reference voltage VREF 324 as the second input 304 to the differential amplifier 300 .
Even though an OR gate would generally output a ‘1’ when at least one of its inputs is high, this does not happen because an I/O pin cannot simultaneously support conflicting I/O standards. Therefore, even though an OR gate 340 is shown in FIG. 3 , one skilled in the art should appreciate that an XOR gate or any similar logic component that produces a high output whenever at least one or exactly one of the inputs is high can be used to control the enable signal to the differential amplifier 304 . Additional circuitries that govern this behavior are not shown in order to not obscure the present invention.
TABLE 1
TABLE 1
Differential
SSTLIE
LVDSIE
Amplifier
Switch
0
0
Disabled
N/A
0
1
Enabled
INA
1
0
Enabled
VREF
1
1
N/A
N/A
As shown in FIG. 3 and Table 1, the OR gate 340 selectively enables and disables the differential amplifier 300 and the buffer 360 based on the input signals received by input terminals 342 and 344 respectively. When the differential amplifier 300 is disabled, the buffer 360 is enabled. In some embodiments, the buffer 360 is a TTL buffer. The output of the OR gate 340 is inverted with an inverter 352 and coupled to the enable terminal 362 of the buffer 360 . Therefore, when both the inputs to input terminals 342 and 344 are low, the differential amplifier 300 will be disabled and the buffer 360 will be enabled. When either one of the inputs to input terminals 342 and 344 is high, the differential amplifier 300 will be enabled and the buffer 360 will be disabled. The input terminal 364 of the buffer 360 receives an input signal IN. In some embodiments, this input signal is the same input as the one received by the input terminal 302 of the differential amplifier 300 . The output of the buffer 360 and the output of the differential amplifier 300 are coupled as a single output 370 of the circuit.
FIG. 4 , meant to be illustrative and not limiting, shows a differential buffer coupled to two switches 400 , 440 as an embodiment in accordance with the present invention. The switch 400 with two input terminals 402 , 404 is coupled to the second input terminal 414 of a differential buffer 420 . The first input terminal 402 of the switch receives a first input signal and the second input terminal 404 of the switch receives a second input signal. In some embodiments, the first input signal is an inverted version of the signal received at the first input terminal 412 of the differential buffer 420 and the second signal is a pre-specified reference voltage. The switch 400 can be programmed to selectively output either the signal received by the first input terminal 402 or the signal received by the second input terminal 404 . One skilled in the art should also appreciate that even though a switch 400 is shown in FIG. 4 , a similar logic element can be used to replace the switch 400 . For example, a 2-to-1 multiplexer can be used in place of the switch 400 to selectively transmit one of the two inputs as an input to the differential buffer 420 .
As shown in FIG. 4 , the differential buffer 420 has two input terminals. The first input terminal 412 receives a first signal and the second input terminal 414 receives a second signal—either an inverted version of the first signal 402 or a reference voltage 404 as output from the switch 400 . In some embodiments, the differential buffer 420 is always enabled and the enable terminal 422 is tied to a ‘1’. In other embodiments, the differential buffer 420 is controlled by other logic elements and is selectively enabled. The output of the differential buffer 420 is coupled to an input terminal 444 of a second switch 440 . The second switch 440 has two input terminals 442 , 444 . The first input terminal 442 receives a first input signal. In some embodiments, the first input signal is the same signal received by the first input terminal 412 of the differential buffer 420 . The second input terminal 444 of the second switch 440 receives the output of the differential buffer 420 . The switch 440 can be programmed to select between the two inputs. Even though a switch 440 is shown, one skilled in the art should appreciate that a similar logic element like a multiplexer can be used to select between the two signals. The switch 440 will output either the differential signal from the differential buffer 420 or the input signal received by the first input terminal 442 of the switch 440 . In some embodiments, the switch 440 is programmed to transmit a differential signal when the switch 440 selects and transmits the output from the differential buffer 420 . The output 448 transmits the appropriate output based on the selection of the switch 440 .
FIG. 5 , meant to be illustrative and not limiting, shows a process flow 500 to buffer two types of differential signals using a single input buffer in accordance with an embodiment of the present invention. The process starts with an input buffer receiving a first signal as a first input in operation 510 . In some embodiments, the first signal is a user input signal. The type of signal that the input buffer is buffering is checked in operation 520 . In one embodiment, software can be programmed to check the type of signal that the input buffer is buffering in a user design. In another embodiment, external circuitries that are not shown in order to not obscure the present invention are used to determine the type of signal that the input buffer is buffering. A second signal is received at the input buffer as a second input in operation 530 when the input buffer is buffering an LVDS signal. In some embodiments, the second signal is an inverted version of the first signal. A third signal is received at the input buffer as a second input in operation 540 when the input buffer is buffering an SSTL or an HSTL signal, as illustrated in FIG. 3 . In certain embodiments, the third signal is a reference voltage within the range of 1.2VCCN to 2.5VCCN. However, this is meant to be exemplary and not limiting. The buffer can also receive a fourth signal as an enable input to the buffer, as illustrated in FIG. 3 . The enable signal will enable or disable the buffer based on the value of the fourth signal. In a preferred embodiment, the enable signal corresponds to the type of signal that the input buffer is buffering at any one time.
Although the method operations were described in a specific order, it should be understood that other operations may be performed in between described operations, or described operations may be adjusted so that they occur at slightly different times, or described operations may be distributed in a system which allows the occurrence of the processing operations at various intervals associated with the processing, as long as the processing of the overlay operations are performed in a desired way.
Although the foregoing invention has been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications can be practiced within the scope of the appended claims. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.
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A buffer circuit for using one buffer for multiple differential I/O standards is disclosed. The buffer circuit includes a differential input buffer. The first input of the differential input buffer may receive an input and the second input is coupled to a switch. The switch may be a one-time-programmable switch. The switch has a coupling to transmit a signal to the second input of the differential input buffer. The switch may be programmed to selectively transmit different signals to the differential input buffer. The first input terminal of the switch may receive an inverted version of the input signal and the second input terminal of the switch may receive a reference voltage. The buffer may transmit an LVDS signal or an SSTL signal or an HSTL signal. Using one differential buffer for multiple I/O standards may reduce the overall die size and may save space on the die.
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FIELD OF THE INVENTION
This invention relates to systems having peripheral devices coupled to host devices through an interface. In particular, the invention relates to providing variable latency (or flow) control and reporting errors for read data from a peripheral device, using a read data strobe signal received at a host device.
BACKGROUND
Modern electronic systems include volatile or non-volatile memory that is used to store code or application data processed by application software. Recent developments of flash non-volatile memory (Flash) and dynamic random access memory (DRAM) have reduced data corruption, such that data reliability is very high and in most cases data is read out of these devices assuming no corruption. Even with these memory types, a status register in the memory may carry information about any data read failures that do occur. However, a host usually does not read the status after every data access due to additional communication time overhead in the system that would reduce system performance.
Corruption in the data read at the peripheral may result in erroneous code or data transmission to a processing device, e.g., a central processing unit (CPU) or the like. Processing erroneous code or data in turn can lead to system failures, which are hard to detect. And, recovery from system failure is very time consuming. For example, if a memory is used in a network, this system failure could cause significant down time, which is not acceptable in many systems. Such systems need immediate notification of any detected read error and provide a signal separate from the memory read data to indicate to the host that a read error has occurred.
Many systems also transfer data at high speeds, such that the period of time during which each bit of data is valid is very short, making it difficult for the host to know the optimal point in time to capture valid data. These systems often include a signal separate from the data to indicate the optimal point in time to capture valid data. This signal is often referred to as a receive data clock (RDC), a data-in-out strobe (DQS), or read data strobe (RDS). While the RDS provides an indication of the best point within a clock cycle to capture data, the RDS is expected to transition between signal levels within a fixed number of clocks following the beginning of a read access and to continue regular transitions during any set of sequential read accesses.
SUMMARY
Provided herein are system, apparatus, methods and/or combinations and sub-combinations thereof, for using a single read data strobe (RDS) signal received at a host device from a peripheral device to perform multiple functions that indicate a variable latency from the start of a read access to when data is first valid, to provide a timing reference relative to the read data for the optimal point in time to capture the data, to control the flow of transfers in a series of read accesses by indicating when subsequent data is again valid, and to report any error in the read access of the peripheral device.
An embodiment includes a method for interpreting information from the RDS signal at the host interface. The method is based on counting clock pulses until a RDS signal transition between voltage levels is received at the peripheral controller of the host interface. According to one operative mode, data is transmitted without error when the RDS signal transitions are received at expected time intervals. According to a second operative mode of this embodiment, an error is communicated to the host and data is not transmitted from the peripheral, when the RDS signal is not received before expiration of a maximum waiting time at the peripheral controller. According to a third operative mode of this embodiment, the data is sent only when the RDS signal transitions, and these transitions may vary in the time interval between the beginning of a read access and first transfer of data or between subsequent data transfers in a series of transfers, to control the flow (rate) of transfers.
A further embodiment includes a method for detecting the read data error using a peripheral device and a received RDS signal. The operation includes loading a counter with a predetermined maximum waiting time and counting down until the RDS signal transition is received from the peripheral device. If the counter has counted down to zero before reception of the RDS signal transition at the peripheral controller, an error response is sent to the processing unit of the host device with no data transmission. Otherwise, valid data is captured and transmitted to the host.
Further features and advantages of the invention, as well as the structure and operation of various embodiments of the invention, are described in detail below with reference to the accompanying drawings. It is noted that the invention is not limited to the specific embodiments described herein. Such embodiments are presented herein for illustrative purposes only. Additional embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein.
BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES
The accompanying drawings, which are incorporated herein and form part of the invention description, illustrate the present invention and, together with the detailed description, further serve to explain the principles of the invention and to enable a person skilled in the relevant art(s) to make and use the invention.
FIG. 1 illustrates an electronic device subsystem including a host coupled to a peripheral device.
FIG. 2 illustrates interface connections between a host interface and a peripheral interface.
FIG. 3 illustrates a peripheral interface, according to an embodiment of the disclosure.
FIG. 4 illustrates a host interface, according to an embodiment of the disclosure.
FIG. 5 is a flow diagram depicting a method, according to an embodiment of the disclosure.
FIGS. 6, 7, and 8 are timing diagrams, according to an embodiment of the disclosure.
The features and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. The drawing in which an element first appears is indicated by the leftmost digit(s) in the corresponding reference number.
DETAILED DESCRIPTION
This description discloses one or more embodiments that incorporate the featires of this invention. The disclosed embodiment(s) merely exemplify the invention. The scope of the invention is not limited to the disclosed embodiment(s). The invention is defined by the claims appended hereto.
The embodiment(s) described, and references in the description to “one embodiment”, “an embodiment”, “an example embodiment”, etc., indicate that the embodiment(s) described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is understood that it is within the knowledge of one skilled in the art to use such a feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
Embodiments of the invention may be implemented in hardware, firmware, software, or any combination thereof. Embodiments of the invention may also be implemented as instructions stored on a machine-readable medium, which may be read and executed by one or more processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing device). For example, a machine-readable medium may include read only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; flash memory devices; electrical, optical, acoustical or other forms of propagated signals, and others. Further, firmware, software, routines, instructions may be described herein as performing certain actions. However, it should be appreciated that such descriptions are merely for convenience and that such actions in fact result from computing devices, processors, controllers, or other devices executing the firmware, software, routines, instructions, etc.
Before describing such embodiments in more detail, however, it is instructive to present an example environment in which embodiments of the present invention may be implemented.
FIG. 1 illustrates a system 100 , according to an embodiment. In one example, system 100 is an electronic device subsystem including a host device 102 coupled to a peripheral device 104 .
Host device 102 may be a host system-on-a-chip (SoC). Host device 102 may include a host interface 106 coupled to a central processing unit (CPU) 108 through an internal system bus 112 . CPU 108 can be part of, but not limited to, a personal laptop or desktop computer or a mobile device (not shown).
Peripheral device 104 may include a peripheral device interface 110 .
In one example, host device 102 may communicate with peripheral device 104 through an interface bus 114 , which connects host interface 106 to peripheral interface 110 .
In one example, peripheral device 104 can be, but is not limited to, a NAND Flash memory, a NOR Flash memory, or a DRAM memory.
It is to be appreciated that, while FIG. 1 shows only one host interface 106 , host device 102 may include additional host interfaces.
FIG. 2 illustrates detailed interface connections between host interface 106 and peripheral interface 110 , according to an embodiment.
In this example, interface bus 114 connects host interface 106 to peripheral interface 110 through one or more channels or signal paths between peripheral device 104 and host device 102 . It should be noted that the term “signal” may be used interchangeably herein to refer to the actual information or the channel connection itself that is used to transmit the signal information, as it may be apparent to one skilled in the relevant art.
In the example shown, there may be four uni-directional channels ( 220 - 226 ) from host interface 106 to peripheral interface 110 and one uni-directional channel 230 from peripheral interface 110 to host interface 106 . A chip select channel 220 may be used to select one of many chips in peripheral device 104 during an operation. A clock signal channel 222 may be used as a reference clock from host device 102 to peripheral device 104 . A control channel 224 transmits control information. An address channel 226 may be used to transmit the address location to peripheral interface 110 . A read data strobe (RDS) signal may be transmitted through channel 230 from peripheral interface 110 to host interface 106 . In one example, the RDS signal is used to validate data transmission and indicate read error or variable timing information to host device 102 .
In one example, there may be a bi-directional channel ( 228 ) from peripheral interface 110 to host interface 106 . Data in/out signals may be transmitted through bi-directional channel 228 to send data from peripheral interface 110 to host interface 106 . While in this example the data in/out signal is transmitted through bi-directional channel 228 , it is to be appreciated that two different uni-directional channels may also be used in place of the bi-directional channel. The control, address, data in/out channels may also share a common set of signals via time division multiplexing.
FIG. 3 is a more detailed internal block diagram of peripheral interface 110 , according to an embodiment. In this example, peripheral interface 110 may include several logic blocks coupled to one another through interface connections 340 . For example, input logic 342 , control logic 344 , function block 346 , and output logic 348 .
In one example, input logic block 342 receives chip select signal from channel 220 , the reference clock signal from channel 222 , control information from channel 224 , address information from channel 226 , and have data input or output signals connect through channel 228 .
In one example, function block 346 determines a function performed by peripheral device 104 .
In one example, output logic 348 is responsible for communicating data in channel 228 and RDS signal in channel 230 back to host device 102 .
In one example, control logic block 344 communicates with input logic 342 , that may determine the time and order of different function execution at peripheral interface 110 .
Output logic block 348 may include a data output buffer 350 , latency control mechanism 352 , and error detection block 354 . Data output buffer may store data for transmission to host device 102 ( FIG. 1 ) through data in/out channel 228 . Latency control mechanism 352 may manage the RDS output so that it matches the time when data is ready for transmission, and communicates the RDS signal back to host device 102 . Error detection block 354 may be used to identify when there is an error in the data and communicates with latency control mechanism 352 through channel 356 to prevent transmission of the RDS signal.
FIG. 4 is a more detail internal block diagram of host interface 106 , according to an embodiment. In this example, host interface 106 may include several logic blocks coupled to one another through interface connections 460 . The logic blocks may include input logic 462 , control logic 464 , and output logic 466 .
In one example, output logic 466 can be used to transmit one or more signals, e.g., chip select, reference clock, control, address, and data out, from host interface 106 to peripheral interface 110 ( FIG. 1 ), through channels 220 to 228 .
In one example, input logic 462 receives and processes data through channel 228 and the RDS signal through channel 230 from the peripheral 104 , a host internal bus interface 468 configured to communicate with the central processing unit 108 through internal system bus 112 by receiving the internal system clock through channel 470 , address data through channel 472 , and transmitting read data through channel 474 and a response signal through channel 476 to indicate valid or erroneous transmission. In one example, a control logic 464 may determine the time and order of different function execution at host interface 106 .
Input logic 468 may further comprise a data input buffer 480 responsible for receiving the read data through channel 228 from peripheral device 104 , an RDS detect and clock generation circuit 482 , which, in one example, may receive the RDS signal through channel 230 and delay it so that its rising edge is shifted to occur in the middle of the valid data packet; and a latency error detection circuit 484 , which can detect whether an error has occurred. The delayed RDS signal through channel 230 may act as a receive-clock and may be used for data capturing.
In one example, the delayed RDS signal may be communicated to data input buffer 480 through channel 486 . The RDS may be communicated to the latency error detection circuit 484 through channel 488 . An error response from circuit 484 may then be transmitted back to host CPU 108 through interface connections 460 , host internal bus interface 462 , and response channel 476 .
FIG. 5 shows a flow diagram outlining a method 500 , according to an embodiment. For example, method 500 can detect an RDS signal and identify valid, or delayed data read and transmission between peripheral device 104 and host device 102 . It is to be appreciated that method 500 may not occur in the order shown, nor include all operations shown. Merely for convenience, elements in FIGS. 1-4 will be used to perform operations shown in method 500 .
In step 502 , a read command and address is transmitted from a host device interface to a peripheral device interface.
In step 504 , once the peripheral device has obtained enough information to identify the read command and begin access of the location, a counter in the host interface begins counting clock pulses generated from a reference clock. In one example, a counter counts up from a zero value. It is to be appreciated by one skilled in the relevant art that other counting schemes may be employed, such that the counter may be able to track the latency values.
In step 506 , a determination is made whether the RDS signal has been received. Receiving the RDS signal refers to toggling of the signal from one logic state to another. This may be from a high logic state to a low logic state, or vice-versa. The terms “arrival” and “reception” of the RDS signal may be interchangeably used herein to refer to toggling of the RDS signal from one logic state to another. If the RDS signal has been received, data is reported from peripheral device 104 to host device 102 (step 512 ). As such, the RDS signal may be used as a time reference to capture a read data at the host device interface 106 . Once a read data is reported to host device 102 (step 512 ), a determination is made whether more data is expected (step 514 ). If more data is expected, method 500 resets the count to zero and restarts at step 503 , and if not, method 500 ends.
Returning to step 506 , if the RDS signal is not received, method 500 branches out to step 520 , where the counter value is compared to a predetermined maximum latency. The predetermined maximum latency may be programmable and may be set by the software during an idle state of the system. There may be a plurality of predetermined latencies, for example one for the initial access time until the first set of data is sent back to host device 102 from the peripheral device 104 , and a second latency related to the delay in reading data at a boundary crossing between data pages in peripheral device 104 .
If in step 522 the counter value is below the maximum predetermined latency, the method returns to step 504 , i.e. the counter continues to count until the RDS signal arrives. If the counter value is above the maximum predetermined latency before the RDS signal has been received, in step 524 the data is not sent to host device 102 , and an error is reported in step 526 , as the maximum waiting time for RDS signal reception has been exceeded. After one cycle has been completed according to method 500 , the system may proceed to an idle state or a subsequent read operation (not shown in FIG. 5 ).
Method 500 may be used with a first predetermined maximum time of receipt and a second predetermined maximum time of receipt (not shown in FIG. 5 ). For example, method 500 may be used for receiving the RDS signal before a first predetermined maximum time of receipt, thereby controlling the latency from a read request to return of data for a first data returned. Further, the RDS signal may be received at any time before a second predetermined maximum time of receipt. As such, method 500 allow the controlling of the latency between data transfers to provide flow control of a rate of transfers in a series of data transfers. Further, method 500 allows receiving the RDS signal for each data element transfer of a plurality of data element transfers, when the read request is for the return of multiple read data elements.
The method of operation according to the embodiment described in FIG. 5 indicates that the RDS signal 230 may serve an at least threefold functionality. First, it may be used as a receive-data clock relaying timing information and indicating when the data is valid on interface bus 114 , when the RDS signal in channel 230 is received. Second, it may provide variable latency information by delaying the first or subsequent data transfers in a series of transfers. Third, it may indicate a read data error and send an error response without data transmission from peripheral device 104 to host device 102 , when it is not received before expiration of a time period corresponding to a predetermined maximum latency time. It is to be appreciated by one skilled in the art that additional functionalities may be imparted to the RDS signal according to the various embodiments described herein.
According to one aspect of this disclosure, the read data error may refer to the initial access of a data page, or a page boundary crossing at a peripheral device, or any other operation that may require some timing delay. The read operation may be any of single word read, burst read, where at least two words are read in sequence, or wrapped read where data read may begin for example in the middle of a page, continue until the end of an aligned block of the same word size, then return to the beginning of the same word size block and continue to the point where the data reading begun.
FIG. 6 shows a timing diagram 600 at an interface bus when there are no errors in the data transmission, according to embodiments of the disclosure. For example, data packets associated with a peripheral device that is a memory device are used. In this example there is a predetermined latency of five clock pulses. However, one skilled in the pertinent art may appreciate that it is not limited to this particular device or latency time and that similar timing diagrams may be produced for other types of peripherals and plurality of first predetermined latency times, according to the example embodiment of this disclosure.
At time 602 , a signal in chip select channel 220 and a RDS signal in channel 230 toggle from a high logic state (“high”) to a low logic state (“low”) to indicate the onset of a read operation. At the same time 602 , the read command and data address are sent from CPU 108 , to peripheral device 104 , through host interface 106 and interface bus 114 . The data packets transmitted from CPU 108 of host device 102 to peripheral device 104 appear in data in/out channel 228 of the interface bus 114 during time period 604 . For example, data packets “ 90 ”, “ 01 ”, “ 25 ”, “ 45 ”, “ 00 ”, “ 0 E”, which are coded to indicate a read command and the address location to peripheral device 104 .
After time period 606 , peripheral interface 110 has received adequate information to begin access of the memory. At this time, a counter (not shown) begins to count clock pulses as generated by the clock signal in channel 222 and host interface 106 waits for the RDS signal in channel 230 . In this example, it is assumed that the initial value of the counter has been set to zero, however, the implementation is not limited to this counting scheme.
During time period 608 , a five clock pulse latency occurs. RDS signal in channel 230 toggles from low to high, indicating that it has been received at host interface 106 . At the same time, data in/out channel 228 transmits data from peripheral device 104 back to host device 102 , as indicated by the data packets “AB”, “CD”, “ 98 ”, “ 76 ”, which are validated by the rising and falling edges of the RDS signal in channel 230 .
In one implementation of this embodiment, the host interface 106 issues a response through internal system bus 112 to CPU 108 , corresponding to valid transmission without error. This may be an “OKAY” response when the internal system bus is an AHB or AXI bus, but it is not limited to this implementation.
FIG. 7 shows a timing diagram 700 at an interface bus when there is an error after the initial access of a data page, according to embodiments of the disclosure. In this example, there is a first predetermined latency of five clock pulses and the second predetermined latency is equal to the first predetermined latency. However, similar timing diagrams can be produced for other predetermined latencies or for a second predetermined latency greater than the first predetermined latency.
At time 702 , a chip select signal in channel 220 and a RDS signal in channel 230 toggle from high to low to indicate the onset of a read operation. At the same time 702 , the read command and data address are sent from CPU 108 , to peripheral device 104 , through host interface 106 and interface bus 114 . The data packets transmitted from CPU 108 of host device 102 to peripheral device 104 appear in data in/out channel 228 of interface bus 114 during time period 704 . For example, data packets “ 90 ”, “ 01 ”, “ 25 ”, “ 45 ”, “ 00 ”, “ 0 E”, which are coded to indicate a read command and the address location to peripheral device 106 .
After time period 706 , peripheral interface 110 has received adequate information to begin access of the memory. At this time, a counter begins to count clock pulses as generated by the clock 222 and host interface 106 waits for the RDS signal in channel 230 . In this example, it is assumed that the initial value of the counter has been set to zero, however, the implementation is not limited to this counting scheme.
After time period 708 and five clock pulses, the RDS signal has not toggled back to high, indicating an error in the data. The data is not transmitted through the data in/out channel 228 . In one implementation of this embodiment, host interface 106 issues an error response through internal system bus 112 to CPU 108 , corresponding to error in the read data. For example, the error message can be a “SLVERR” for an AXI or AHB internal system bus, but it is not limited to this implementation.
FIG. 8 shows a timing diagram 800 at an interface bus when there is an error at a page boundary crossing, according to embodiments of the disclosure. In this example, there is a plurality of first predetermined latencies: one comprising five clock pulses and referring to the initial access latency, and one comprising three dock pukes and referring to a latency across a boundary crossing.
At time 802 , the chip select signal in channel 220 and a RDS signal in channel 230 toggle from high to low to indicate the onset of a read operation. At the same time 802 , the read command and data address are sent from CPU 108 , to peripheral device 104 , through host interface 106 and interface bus 114 . The data packets transmitted from CPU 108 of host device 102 to peripheral device 104 appear in the data in/out channel 228 of interface bus 114 during the time period 804 . For example, data packets “ 90 ”, “ 01 ”, “ 25 ”, “ 45 ”, “ 00 ”, “ 0 E”, which are coded to indicate a read command and the address location to peripheral device 106 .
After time period 806 , the peripheral interface 110 has received adequate information to begin access of the memory. At this time, a counter begins to count clock pulses as generated by the clock in channel 222 and host interface 106 waits for the RDS signal in channel 230 . In this example, it is assumed that the initial value of the counter has been set to zero, however, the implementation is not limited to this counting scheme.
During time period 808 , a five clock pulse latency occurs. RDS signal in channel 230 toggles from low to high, indicating that it has been received at host interface 106 . At the same time, data in/out channel 228 transmits data from peripheral device 104 back to host device 102 , as indicated by the data packets “AB”, “CD”, “ 98 ”, “ 76 ”, which are validated by the rising and falling edges of the RDS signal 230 .
After the last data packet “ 76 ” has been transmitted across data in/out channel 228 , the RIDS signal in channel 230 has not toggled back to high before expiration of time period 810 . Since the page boundary crossing latency has been set to three clock pulses, this indicates a read data error across a page boundary. The data is not transmitted through data in/out channel 228 , and an error response is sent to CPU 108 .
It is to be appreciated that the Detailed Description section, and not the Summary and Abstract sections (if any), is intended to be used to interpret the claims. The Summary and Abstract sections (if any) may set forth one or more but not all exemplary embodiments of the invention as contemplated by the inventor(s), and thus, are not intended to limit the invention or the appended claims in any way.
While the invention has been described herein with reference to exemplary embodiments for exemplary fields and applications, it should be understood that the invention is not limited thereto. Other embodiments and modifications thereto are possible, and are within the scope and spirit of the invention. For example, and without limiting the generality of this paragraph, embodiments are not limited to the, hardware, methods and/or entities illustrated in the figures and/or described herein. Further, embodiments (whether or not explicitly′ described herein) have significant utility to fields and applications beyond the examples described herein.
Embodiments have been described herein with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined as long as the specified functions and relationships (or equivalents thereof) are appropriately performed. Also, alternative embodiments may perform functional blocks, steps, operations, methods, etc. using orderings different than those described herein.
References herein to “one embodiment,” “an embodiment,” “an example embodiment,” or similar phrases, indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it would be within the knowledge of persons skilled in the relevant art(s) to incorporate such feature, structure, or characteristic into other embodiments whether or not explicitly mentioned or described herein.
The breadth and scope of the invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
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Disclosed herein are system, apparatus, methods and/or combinations and sub-combinations thereof, for using a read data strobe signal received at a host device from a peripheral device to convey variable latency (flow) control or report an error in the data content read from the peripheral device. Reception of the read data strobe signal before a predetermined maximum latency time, provides variable latency control back to the host by indicating when valid data is available for capture. If the read data strobe signal is not received before expiration of a predetermined maximum latency time, the peripheral controller is indicating a read data error back to the host.
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BACKGROUND OF THE INVENTION
[0001] Prefabricated homes and commercial structures employ roofing units comprising asphaltic courses or shingles securely sealed on a roof deck for subsequent assembly and installation. Many of the processes heretofore employed for affixing asphaltic materials to a roof deck pose several problems involving cost and/or time consuming adherence. For example, certain processes require several days to cure and seal the asphaltic overlay to the deck structure. To overcome this drawback, costly radiant heating has been used to shorten the cure time; however, this solution, because of indirect heating sites, fails to provide uniform sealing results. As a consequence, a roof unit so treated is subject to sections of shingle or strip “blow off”. Accordingly, it is an object of this invention to provide a process to overcome the above problems in an economical and commercially feasible manner. More specifically, it is an object of this invention to provide a process which reduces the asphalt adhesion time to not more than a few hours while simultaneously providing a seal which is uniformly secure over the entire deck surface of a prefabricated roof unit.
SUMMARY OF THE INVENTION
[0002] In accordance with this invention, an unattached asphaltic surface covering on a roof deck is contacted with a covering matrix containing a heating element at a temperature sufficient to cure the asphaltic material and seal it to the deck. The present roofing assembly comprises a wood, metal or concrete roof deck overlaid with asphaltic shingles or courses of asphaltic roofing material and a heatable matrix covering the asphaltic material and having a size and shape adapted to blanket at least a portion thereof; said matrix containing a heating element capable of distributing heat at a temperature sufficient to seal the asphaltic material to the deck.
DETAILED DESCRIPTION OF THE INVENTION
[0003] The heat generating matrix can be a single blanket covering the entire surface of the asphaltic covered roof or it can comprise several individual coverings adapted to cover sections thereof. Depending upon the pliability of the matrix, a single heating blanket, consistent with the roof dimensions, including valleys and ridges, is most preferred. However, in certain cases where the roof includes dormers or many uneven sections, it may be desirable to employ separate heating blankets over individual sections. The heating element embedded in the matrix is capable of generating a temperature of up to about 200° F., preferably between about 115° and about 185° F.
[0004] The blanket, comprising the matrix and the heating element, can be of a thickness of between about ⅛ th and about 2.5 inches, having a weight sufficient to provide intimate contact between the blanket and the asphaltic roofing material; broadly a weight of from about 0.1 to about 2 psi may be employed. However, a thickness of between about ⅕ th to about 1.5 inches is generally preferred. It is found that the weight of the blanket over the asphaltic material also assists in sealing it to the deck and the direct application of confined heat provides uniform attachment of the asphalt to the deck in the area of intended treatment.
[0005] The matrix of the invention is composed of natural or synthetic rubber or other inert material, modified when needed for flexibility, so as to conform with the roof surface. More specifically, the matrix can be composed of woven or non-woven material which can withstand the temperature of asphalt sealing without loss of size or shape integrity. Such matrices include a ceramic wool mat, a glass mat, a mat of silicon rubber and other similar products.
[0006] Although the preferred heating element in the matrix is an electrical metal coil or wire, other heat transmitting means are contemplated within the scope of this invention. For example, a hollow tube or plurality of tubes transporting air, water or oil can be incorporated in the matrix. Solar power can also supply the heat needed in a matrix having one or more reflective surfaces. The heating element can be localized over the area where sealing is needed or it can be distributed throughout or in larger portions of the matrix to heat and seal larger areas of the asphaltic material. Exceptionally good heat distribution is achieved when larger sections of the asphalt is covered with the heat blanket containing spaced heating elements since a uniform heat by convection is achieved in the pockets between the spaces.
[0007] The asphalt roof covering is any of the conventional types which have a curing temperature of between about 100° and about 185° F. The sealing process is cost effective and simply involves placing the above described heating blanket in contact with the asphaltic covered roof deck and heating the blanket to at least the curing temperature of the asphalt for a period sufficient to achieve strong and uniform bonding between the deck and asphalt material which is usually a period of from about 0.25 to about 3 hours; although generally a heating time of not more than 1.5 hours is sufficient. After attachment is complete, the blanket is removed and a wind lift resistant product is obtained. This process is particularly useful for prefabricated roofing where subsequent building assembly is required.
[0008] Reference is now had to FIG. 1 of the drawings which illustrates flexible matrix 2 containing a preferred embodiment of heating element, i.e. serpentine copper alloy wire 4 having connection plug 5 . FIG. 2 is a front view illustrating roofing assembly 6 comprising deck 8 and courses of asphalt covering 10 in contact with heating blanket 12 .
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The process of adhering asphaltic roofing tiles to a roof deck by covering the tiles on the deck with a heat blanket capable of generating a temperature of at least the cure temperature of the tiles thereby sealing the tiles to the deck.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 09/074,851, now U.S. Pat. No. 6,321,384, having a filing date of May 8, 1998, entitled “Noise reduction in cable return paths”, which is a continuation of U.S. patent application Ser. No. 08/347,573, filed on Nov. 30, 1994, now abandoned.
This application also claims the benefit of U.S. Patent Application Ser. No. 60/138,933, entitled “Two-way cable system home ingress monitoring,” filed on Jun. 11, 1999.
BACKGROUND OF THE INVENTION
Cable TV systems, also known as Community Access Television (CATV) Systems, have evolved from simple broadcast systems for television services to bi-directional broadband networks which can carry voice, video and data traffic. This evolution has been accomplished in part by upgrading traditional cable networks to Hybrid Fiber Coaxial (HFC) networks which utilize fiber optic systems in conjunction with active electronics and coaxial cables to deliver broadband signals to the home. These networks also support the reception of return path signals, which are signals generated by units in or near the subscriber and which send data or voice signals from the subscriber or business location to the network through the cable system.
By providing advanced telecommunications services over HFC networks, network operators can enhance their service offerings to include voice, Internet access, and other new and unique multimedia services. Although some of these services may have minimal requirements for the transmission of data from the residence to the head-end and the network, many applications require the reliable transport of data and, in fact, need to have guaranteed and reliable bandwidth.
For example, voice communications can be carried over an HFC network based either on traditional circuit switched technology or emerging Internet Protocol (IP) standards. In either of these transport modes, an unreliable and noisy return path can cause degradation in service and even loss of an active call.
Because the configuration of the cable system is multipoint-to-point from the subscribers to the head-end, the return path has the undesirable characteristic of accumulating or “funneling” noise towards the head-end. The number of subscribers connected to the network is typically greater than 500, and many subscribers can have power dividers (splitters) installed in their homes to allow connection of multiple settops to the cable network. The result of the large number of subscribers and the multiple connections in the home is that there are a large number of points on the cable network where undesirable signals can enter the return path. The commonly used term for undesirable signals on the cable return path is ingress. Ingress is typically, but not limited to, AM short-wave broadcast signals and industrial and atmospheric noise, which can enter on the drop cable connecting the subscriber to the cable plant connection termed the tap, and via the coaxial wiring in the subscriber residence or business location. The coaxial wiring used in the home may be of low quality, and will allow ingress because of the low amount of shielding provided with respect to high quality coaxial cable which has a dense braided wire shield which provides high isolation of the center conductor from external electromagnetic fields. The coaxial wiring in the home is also typically unterminated, and can act as an antenna since currents generated on the outside of the shield can to some extent couple to the inside of the shield at the unterminated end and subsequently excite the center conductor. The accumulation of noise on the return path has adversely limited the use of the return path for many purposes.
For the foregoing reasons, there is a need for a method to detect and characterize ingress on the return path and take appropriate action based on this characterization.
SUMMARY OF THE INVENTION
The present invention encompasses a method for detecting the presence of return path ingress, and characterizing the detected ingress, and then mitigating the return path based on the characterization. This characterization may occur at a location inside or near the subscriber residence or business, or at a test point in the network, or at a head-end. For example, this location may be a communications gateway near or at the subscriber location. Alternatively, this location may be a telephone test point (TTP) in the network, or a Cable Modem Termination System (CMTS) at the head-end.
In one embodiment, each ingress event may be monitored over a pre-determined time interval, a corresponding frequency band may be measured, and a time/frequency map may be created indicating the time and frequency band of each ingress event. Then, the time and frequency map may be analyzed to determine when the events occurred and the frequency band where ingress events have been received. Furthermore, the time/frequency map may be used to determine the characteristics of each ingress event, e.g., whether it was a wide-band ingress event or a narrow-band ingress event. The ingress characteristics assist in determining if signals from a residence should be attenuated, or if the home should be disconnected from the return path.
The information from the time and frequency may be used alone or in conjunction with other network management information to determine offending residences, and determine the appropriate action which should take place, including dispatching of a craftsperson to look for broken cable shielding or to determine if there are radio frequency transmitters such as amateur radio systems which are the source of the ingress.
There are a plurality of ways to collect this time/frequency map information in accordance with the present invention. In one embodiment, the entire return band may be monitored to measure individual sub-bands within the return path spectrum, and to create a map representing the time and frequency dependence of the ingress events. Then, the time/frequency map may be used to distinguish narrowband ingress events from wideband ingress events. With the help of time/frequency map, harmful ingress events may be more readily detected, and mitigating actions may be taken more readily. The mitigation may be accomplished by either disconnecting the return path at the communications gateway or attenuating the return path signal.
In another embodiment, the information on channel usage may be obtained and used to distinguish active sub-bands from inactive sub-bands. The presence of ingress events may be detected in either the active or inactive sub-bands, and a time/frequency map may be created based on the detected ingress events. The channel usage information may be retrieved from the head-end that can include network management equipment and databases that have channel information available. Alternatively, the channel usage may be detected automatically at the communications gateway. Automatic detection can be accomplished by estimating the Power Spectrum Density (PSD) of a return path signal, correlating the PSD with a set of stored PSDs and determining the peak correlation frequency and frequency band in use.
The principles of the present invention are flexible and the detection of the ingress can occur at the head-end or may occur within the communications gateway. The detection of ingress may be accomplished by measuring an average return path signal power in the return frequency band and comparing the average return path signal power to a detection threshold. Based on the comparison, a determination that an ingress event is present is declared when the average power exceeds the detection threshold.
These and other features and objects of the invention will be more fully understood from the following detailed description of the preferred embodiments which should be read in light of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and form a part of the specification, illustrate the embodiments of the present invention and, together with the description serve to explain the principles of the invention.
In the drawings:
FIG. 1 illustrates a two-way cable architecture for providing telecommunications services;
FIG. 2A illustrates a communications gateway architecture;
FIG. 2B illustrates a communications gateway architecture with external RF module;
FIG. 3A illustrates a system for acquisition and processing of return path monitoring signals;
FIGS. 3B , 3 C, and 3 D illustrate acquisition stages;
FIG. 4 illustrates full-band ingress monitoring;
FIG. 5 illustrates sub-band ingress monitoring;
FIG. 6 illustrates sub-band ingress monitoring with channel use information;
FIGS. 7A and 7B illustrate active band monitoring;
FIG. 8 illustrates a flow chart for channel usage detection;
FIG. 9 illustrates an exemplary time/frequency map.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In describing a preferred embodiment of the invention illustrated in the drawings, specific terminology will be used for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
With reference to the drawings, in general, and FIGS. 1 through 9 in particular, the method of the present invention is disclosed.
FIG. 1 illustrates a bi-directional cable system comprising a head-end 100 , a network interface which is represented herein by a Cable Modem Termination System (CMTS) 105 and which may be connected to a channel usage information database 115 . Use of the CMTS 105 to represent the network interface is not a limitation to the present system. The present system can use any network interface for receiving upstream signals sent by a modem over the HFC network. The head-end 100 contains return path receiving equipment which can receive signals from fiber optic cables 108 . In a preferred embodiment, separate cables are used for the transmission of fiber optic signals to a node 120 and for the reception of fiber optic signals transmitted from node 120 to head-end 100 . Return path receiving equipment and methods of detecting return path signals at cable head-ends are well known to those skilled in the art.
From node 120 signals are transmitted over coaxial cable 109 through active amplifiers 125 . Signals propagating down a coaxial cable 109 are intercepted by tap 127 which routes a portion of the signal to a Communications Gateway (CG) 140 located at or near a residence 152 . A drop cable 221 is used to connect tap 127 to CG 140 . In a preferred embodiment, drop cable 221 is a coaxial cable. When used herein, the term “communications gateway” (CG) refers to a device for transmitting and receiving data, voice or video signals over an HFC network. Alternative terminology for a communications gateway includes a Broadband Terminal Interface (BTI) or Coaxial Termination Unit (CTU). The term “communications gateway” is not intended to be limiting and encompasses equipment which is located on the outside of the home, in the home in a centralized location such as attic, basement or equipment closet, or in another location in the home. Businesses can also use communications gateway type devices for the transmission and reception of data, voice or video signals.
As illustrated in FIG. 1 , the residence 152 can also contain a set-top box (STB) 155 which is typically connected to a television 150 and a PC 135 which can contain a cable modem. These units are typically connected through a splitter 145 to the communications gateway 140 which is coupled to the HFC network.
A telephone 147 can be supported by communications gateway 140 which provides traditional voice services by transmitting and receiving telephone signals and converting them to cable compatible signals. Telephone service supported by the CG 140 may be circuit switched or Internet Protocol (IP) based telephone service.
As shown in FIG. 1 , signals from the CMTS can be routed to the Internet/private network 110 . These signals can be in IP format but may also be carried as circuit switched signals. When carried as circuit switched signals, the network used is the traditional Public Switch Telecommunications Network (PSTN).
A network management system 160 may also be connected to the Internet/private network 110 and may also be able to access an ingress database 165 . Ingress database 165 is used to record ingress events and can be used in conjunction with network management system 160 to establish the thresholds that indicate the presence of unacceptable levels of ingress in residence 152 . The network management system 160 can also provide alarm readouts, trends or performance reports to a network operator. In one embodiment, the network management system 160 retrieves spectrum data from CG 140 and performs fault detection analysis on the retrieved spectrum data. The network management system can also store the spectrum data in a database for historical trending or other temporal analysis.
FIG. 2A illustrates an architecture for CG 140 . In one embodiment, CG 140 contains an RF module 200 which is capable of receiving signals from the drop cable 221 connected to tap 127 and transmitting those signals to an in-home cable 223 which is typically connected to the splitter 145 . A bidirectional coupler 210 is used to couple signals from drop cable 221 to a cable modem (CM) port on CG board 220 . The RF module permits the transmission of downstream signals to devices in the home and at the same time allows return path signals to be transmitted from STB 155 , PC 135 , or other devices in the home which support bi-directional communications over the HFC network. Simultaneously, the CG 140 contains a communications gateway board (CGB) 220 which can support additional voice services and receive signals from the drop cable 221 through use of coupler 210 .
The CG 140 can support telephone services through use of a Network Interface Module (NIM) 230 which supports phone services through a series of RJ11 jacks 231 . In a preferred embodiment, the communications gateway 140 also has a data interface which provides data services through RJ45 jack 232 .
Referring to RF module 200 illustrated in FIG. 2A , the module contains a diplexer 205 which is used to separate out forward pass signals which are typically in the 50 to 750 MHz range of the spectrum from return path signals, which are typically in the 5 to 42 MHz portion of the spectrum. Diplexing of signals on bidirectional HFC plants is well known to those skilled in the art.
In a preferred embodiment, the RF module 200 contains a forward path attenuator 209 which is used in conjunction with an amplifier 207 to provide the appropriate levels in the forward path.
In the return path, a passive monitoring tap 202 is used to extract a portion of the return path signal arriving on in-home cable 223 . The extracted portion is then directed towards the CGB 220 where a monitoring function is performed. An attenuator/switch 203 is used in the RF module 200 to attenuate or remove return path signals when ingress from that location is determined to be unacceptable. In a preferred embodiment, an amplifier is also present in the return path allowing control of signal levels subsequent to the attenuator/switch 203 . An output of a downstream DC 204 can be used to capture ingress that has entered the cable drop within the frequency range 5-42 MHz as shown in FIG. 2 A. Ingress detected from this output can be reported to the network management system 160 or to Communication gateway element management. DC 204 is located on the line between DC 210 and CGB 220 , rather than between amplifier 207 and diplexer 205 to isolate drop-ingress from home ingress amplified by amplifier 207 . A switch 206 is placed at the ingress monitoring input of CGB 220 to time-sequence the outputs of DC 204 and 202 . The downstream DC 204 allows detecting of wideband ingress, which typically enters the plant after the CG 140 .
In one embodiment, the attenuator is realized through the use of an electrically controlled variable resistor. In an alternate embodiment, active electronics configured for attenuation, such as an operational amplifier configured for less than unity gain and programmable by an external control signal, can be utilized. Electrically controlled attenuating elements are well known to those skilled in the art. Alternatively, a switch can be utilized, in which case the control signal forces open the return path and eliminates all signals in the return band that have been generated from devices in the home and have been passed up in-home cable 223 and through diplexer 205 . In one embodiment, a notch filter can be used in place of the switch to eliminate the frequencies that have a signal level above the threshold.
In one embodiment, adjusting the upstream attenuator/switch 203 performs upstream power-level equalization. For example, the attenuator/switch 203 may be initially set to a value that allows signals transmitted from devices in the residence to be received at the head-end. The following algorithm is periodically used to adjust the attenuator/switch 203 . This procedure can be used both when ingress control is being performed as well as when no ingress control processes are active.
The algorithm can be simply expressed as:
Tx_Difference = (Max_Home_Tx_Level − Upstream_CG_Path_Loss − Home_Path_Loss − CM_Tx_Level + CM_Path_Loss + Max_Channel_Band_Delta − Bypass_Calc_Error_Margin);
where (Max_Home_Tx_Level−Upstream_CG_Path_Loss-Home_Path_Loss) is the maximum home device signal level received at the drop interface,(CM_Tx_Level−CM_Path_Loss) is the CG Cable Modem (CM) transmit level at the drop interface, Max_Channel_Band_Delta is the difference in CG CM channel bandwidth and the maximum CM channel bandwidth of 3.2 MHz and Bypass_Calc_Error_Margin is an offset value. Tx_Difference is the upstream attenuation value and is such that the in-home device transmitted signal power density, after losses in the home and the communication gateway 140 , is received at the drop interface at a level relatively equivalent to the CG 140 CM transmit level at the drop interface. Such power level equalization limits ingress coming from the home and entering the cable plant, thus reducing any high ingress levels.
FIG. 2B illustrates an embodiment in which the RF module 200 is implemented without amplifiers. In this embodiment, a bi-directional coupler 210 is present for coupling CM signals to and from drop cable 221 . A high pass filter 240 is used to bypass downstream signals from attenuator switch 203 which is also present in RF module 200 .
In one embodiment, an upstream directional coupler (DC) represented herein as passive tap 202 and a downstream directional coupler 204 are present in the RF module 200 of CG 140 to direct the ingress to CG board 220 for ingress monitoring purposes. In this embodiment, the passive tap 202 is used to capture ingress from the home contained in the 5-42 MHz band while the downstream DC 204 captures ingress coming through the bi-directional coupler 210 within the same frequency range. In this embodiment, as in FIG. 1A , a switch 206 is placed at the ingress monitoring input of CG board 220 to time-sequence the outputs of DC 204 and passive tap 202 . The downstream DC 204 allows detecting wideband ingress which typically enters the plant after the communication gateway 140 .
FIG. 3A illustrates one embodiment of CG board 220 . In the embodiment illustrated in FIG. 3A , an acquisition stage 310 receives signals from an RF module/tap which, referring to FIGS. 2A and 2B , is generated by passive tap 202 . The acquisition stage 310 is connected to a Digital Signal Processing (DSP) unit 320 which in addition to providing voice and data services can be used to process return path information to determine if ingress is present and at an unacceptable level. DSP 320 is coupled to a Random Access Memory (RAM) 340 which is further coupled to a microprocessor 330 . In one embodiment, a power estimator 300 is utilized in conjunction with acquisition stage 310 to determine the presence of ingress. Microprocessor 330 utilizes information from either power estimator 300 or DSP 320 to determine that ingress is unacceptable and to generate an ingress control signal which is used to attenuate the return path signals or open the switch.
In yet another embodiment, the return path signals are monitored at head-end 100 to determine if the ingress levels are unacceptable. If so, the CMTS 105 or other head-end equipment can issue a control signal to CG 140 for disconnection or attenuation of the return path. The head-end 100 may selectively disconnect residences in an effort to determine which home is the source of ingress, or may work in conjunction with CG 140 to determine if the return path signal from that particular residence should be disconnected or attenuated.
Referring to FIG. 3A , a transceiver 350 is utilized for communications over the HFC network. In a preferred embodiment, transceiver 350 is based on the Data Over Cable System Interface Specification DOCSIS specification and can be realized using a number of commercially available chips including those produced by the Broadcom Corporation. Transceivers for communications over bi-directional HFC networks are well known to those skilled in the art.
The DSP 320 , in addition to performing voice processing for telephony services and other related tasks, can also host a digital implementation of the power estimator module. The DSP 320 can run various algorithms using assembly language, C code or other programming languages supported by the DSP.
The microprocessor 330 can direct the switch to isolate the line when the power exceeds the detection threshold either for a single event or for a predetermined number of ingress events. The microprocessor is connected to Random Access Memory (RAM) 340 which may contain data relative to the operation of the CG 140 and the in-home devices. The data may include information regarding the number of STB 155 and PCs 135 with cable modems in the home, the channels which these devices use, and the expected power levels. This information can be obtained from a network management system 160 and can be downloaded to the communications gateway via downstream channels in the cable system. When this information is present, the threshold can be calculated based on the expected transmissions from the in-home devices, rather than the worse case values discussed above. This allows a lower threshold to be established which still permits transmissions from the in-home devices to pass through the CG 140 , but attenuates or disconnects the return path when ingress, as determined by the threshold set in conjunction with information from the network management system 160 and ingress database 165 , is present.
FIG. 3B illustrates one embodiment of acquisition stage 310 . In the embodiment shown, the return path signal from passive tap 202 is processed by a band-pass input filter 360 and subsequently by an analog to digital conversion stage (A/D) 370 which digitizes the signal for subsequent processing by DSP 320 . In this embodiment, it is necessary to sample the return path signal at a rate sufficient to prevent undersampling. In the instance of a 5 to 42 MHz return band spectrum, sampling at 84 MHz in conjunction with band path limiting of the input signal is sufficient.
Referring to FIG. 3C , a down conversion technique is illustrated in which signals from passive tap 202 are received by a band-pass input filter 360 and subsequently down converted using a mixer 380 in conjunction with a local oscillator 385 . The down converted signal is passed through an intermediate frequency filter 375 and to an analog to digital (A/D) converter 370 . An advantage of this embodiment is that different sections of the return path spectrum can be digitized. For example, if IF filter 375 corresponds to a particular sub-band, that sub-band can be digitized and processed for subsequent determination of ingress. By varying the frequency of local oscillator 385 it is possible to select which sub-band will be examined. The advantage of this heterodyning technique is that different sub-bands can be selected for a return path monitoring based on local oscillator 385 , and with the width of those sub-bands being determined by IF filter 375 . In one embodiment, IF filter 375 is programmable such that the sub-bands can be varied in width. This can be useful when sub-bands vary in width from narrow bands on the order of kilohertz wide to wide return bands which may be 2 MHz or more wide.
FIG. 3D illustrates the use of a variable band-pass filter 390 in conjunction with A/D converter 370 . In this embodiment, the variable band-pass filter is controlled both in frequency and width to allow direct digitization of the band of interest.
FIG. 4A illustrates the monitoring of power over a contiguous section of the return band which contains several active channels. In one embodiment power estimator 300 estimates the power over a certain bandwidth Δf, determined by microprocessor 330 . In one embodiment, the power is measured over the 37 MHz band. Power estimator 300 can be implemented using a nonlinear (e.g. squaring) function and a low-pass filter to average the power over a period of time T. In an analog embodiment, a diode can be used for the nonlinear function and an RC circuit can serve as an integrator. Digital implementations are also possible and are based on using an FFT to obtain the PSD of the in-home signal.
In one embodiment, the averaging time is set to a value such that T·Δf>>1. The type of ingress to be detected depends on the choice of T, which cannot be longer than the duration of the signal to be monitored. For impulsive noise, the pulse duration is between 0.1 to 1 μsec for approximately 95% of impulse events, and between 1 to 10 μsec for the remaining impulse events. Narrowband ingress typically extends to several milliseconds and occupies a bandwidth on the order of kHz.
FIG. 4A illustrates monitoring of the return path over a monitoring band 404 . In many cable systems monitoring band 404 will be 5 to 42 MHz. As shown in FIG. 3A an ingress signal 400 is present, along with a STB signal 410 , and a CM signal 420 . An ingress detection threshold 402 is established, based on the well known general characteristics of ingress, the specific characteristics of ingress for that plant, or a combination of the two. The ingress detection threshold 402 may change over time depending on the characteristics of the plant and the services in place. As an example, if more services are utilized the ingress detection threshold 402 may be lowered as compared to an initial value, since ingress may be more critical with additional services than when the services provided were minimal or at a low penetration rate.
In one embodiment, ingress detection threshold 402 is established in head-end 100 and transmitted to communication gateway 140 . In an alternative embodiment, communication gateway 140 establishes ingress detection threshold 402 locally. As previously discussed, ingress detection threshold 402 can vary over time. Ingress database 165 can be utilized to determine an appropriate ingress detection threshold based on historical ingress data. In addition, historical ingress data can be combined with information regarding channel usage, which is available in channel usage information database 115 , to determine the appropriate ingress detection threshold.
As shown in FIG. 4B , the ingress power density over the monitored band 440 can be calculated. When the ingress power density over the monitored band 440 does not exceed ingress detection threshold 402 , no action is necessary. When the ingress power density over the monitored band 440 exceeds the ingress detection threshold 402 , the return path signal can be attenuated, or the return path can be opened through use of a switch to eliminate the ingress.
As an example of full band monitoring, a CM can transmit up to 58 dBmV within a bandwidth of 3 MHz and an STB can transmit up to 60 dBmV within 150 kHz. If the transmit power for these devices is lowered from the maximum transmit power by 10 dB, the worst case threshold can be calculated as the estimated PSD from these data sources over the entire return path.
FIGS. 5A and 5B illustrate sub-band monitoring, in which ingress is monitored within monitoring bands 424 . These monitoring bands can correspond to DOCSIS channels, ranging from 200 kHz to 3.2 MHz, or can be set to a bandwidth which is sufficiently wide to permit rapid acquisition of the power spectral density but narrow enough to resolve a portion of the return band.
As illustrated in FIG. 5B , the ingress power within monitoring bands 500 is measured, and when the ingress power density is greater than the ingress detection threshold, an unacceptable ingress event 510 is declared. Unacceptable ingress event 510 indicates that an unacceptable level of ingress is present in the monitoring bands 500 .
FIGS. 6A and 6B illustrate the detection of ingress with further discrimination between used and unused bands. In this embodiment used bands 610 are distinguished from unused bands 600 , with unused bands 600 not containing any return path signals. The advantage of this embodiment is that an ingress detection threshold within used bands 610 can be established which is different than the ingress detection threshold within unused bands 600 . As illustrated in FIG. 6B , unacceptable ingress events in used bands 620 are distinguished from unacceptable ingress events in unused bands 630 . The different ingress detection thresholds are established based on the expected power levels in the used bands and the allowable ingress levels as determined with respect to the return path signal levels.
FIG. 7A illustrates the monitoring of active channels 710 in a return frequency band 700 . In this embodiment, the communications gateway only monitors channels which have been identified as having return path traffic. As shown in FIG. 7A , channels may be identified as active, and the ingress monitoring techniques previously discussed used to determine if there are unacceptable levels of ingress on these channels.
Information regarding which channels are in use may be obtained from a number of sources, including the CMTS 105 at head-end 100 , or by the CMTS 105 in conjunction with the channel usage information database 115 . The CMTS 105 incorporates channel usage information as part of its operation in allocation of return path bandwidth using the DOCSIS protocol. Since CMTS 105 transmits downstream channel usage information to the CG 140 as part of the DOCSIS protocol, the CG can determine which return path channels are in use and monitor those channels correspondingly. Information regarding the use of return path channels by other in-home devices including STB 155 can also be transmitted to CG 140 , either through DOCSIS or as part of another communication protocol.
FIG. 7B illustrates the monitoring of an active CG channel 720 in the return frequency band 700 . In this embodiment only the return channel being actively used by the CG 140 is monitored. Because this channel is likely to contain critical return path payloads carrying voice and data, it is important to maintain the integrity of the active CG channel 720 . Information from STB 155 which is being carried on another return channel may not be as critical as the information being carried in the active CG channel 720 , and by monitoring the active CG channel 720 only ingress which is present in the active CG channel 720 will result in disconnection or attenuation of the return path. This embodiment offers the advantage that ingress signals at frequencies outside of the active CG channel 720 will not result in disruption of communications in the active CG channel 720 .
FIG. 8 represents a flowchart for a channel recognition method which can be used to identify active channels in the return frequency band 700 . The advantage of this technique is that the CG 140 can automatically identify which channels are in use in the return frequency band 700 and mark them as active channels 710 .
Referring to FIG. 8 the method is performed by receiving an in-house signal 800 . This can be accomplished through use of the CG 140 with return path monitoring capability as illustrated in FIG. 2 A. Once the in-home signal has been received, the power spectral density (PSD) can be determined in an estimate PSD 810 step. Determination of the PSD can be accomplished through use of DSP 320 as illustrated in FIG. 3 A. Upon obtaining the PSD of the received return path signal, a correlation calculation step 820 is performed using the PSD determined in step 810 and a stored PSD 825 . The stored PSD 825 contains a representation of an expected return path PSD. As an example, DOCSIS based devices can utilize Quadrature Phase Shift Keying (QPSK) transmission or Quadrature Amplitude Modulation (QAM). The spectra for these transmissions, including channel width, can be known a priori and stored as part of stored PSD 825 .
Once the correlation calculation step 820 is complete, a “determine frequency at peak correlation” step 830 is performed, followed by a “determine minimum frequency band in use” step 840 . In the “determine minimum frequency band in use” step 840 , the limits of the active channel 710 are determined. These limits are used in conjunction with a stored or calculated PSD mask to determine the parameters for monitoring of the return path frequency band 700 .
FIG. 9 illustrates an exemplary time/frequency map 900 . In the exemplary case of FIG. 9 , the ingress events are monitored over a pre-determined period of time and the results of the monitoring are represented in a matrix format on the map 900 . As shown in FIG. 9 , the time frames (N time frames) are tracked on the horizontal axis and the various frequency bands (K frequency bands) are tracked on the vertical axis. In this exemplary case each of the frequency bands and each of the time frames has a predetermined width.
For each time frame, the PSD of the signal is obtained and the frequency bands having a signal power above the detection threshold are given an integer value 1 . The presence of a “1” indicates the detection of a signal above the detection threshold. Over a window of M time frames a map as shown in FIG. 9 can be obtained. Furthermore, a cumulative sum 920 over the K frequency bands at time frame n (CSF n ) may be computed. Additionally, a cumulative sum 910 over the N time frames at frequency band k(CST k ) may also be computed. The CSF n and CST k may then be used to distinguish a narrowband ingress event from a wideband ingress event. In particular, a narrowband ingress event is declared when the CST k exceeds a threshold, for example, S nb and, a wideband ingress event is declared when CSF n exceeds a threshold, for example, S wb . The principles of the present invention are flexible and different values of threshold may be used. A user may select suitable threshold values based on the application/system in use.
In one embodiment, the width of the frequency band is set equal to 200 kHz. In this embodiment, the threshold S wb is equal to 5, which corresponds to an ingress signal with a bandwidth of 1 MHz. More generally, the threshold S wb can be determined from this equation:
S wb = W Δ f
where W is the minimum bandwidth of a wideband signal and Δf is the width of the frequency band used.
In this embodiment, a narrowband ingress event declaration may be based on a threshold S nb corresponding to an ingress duration of several milliseconds. For example, by considering a narrowband ingress event of duration 100 ms and a 10 ms time between received detection measurements, the threshold S nb can be set to 10.
The time/frequency map results may be stored and time averaged at the subscriber location or near the subscriber location with the information being used to set thresholds for entire return band monitoring or sub-band monitoring, or to adjust the time or frequency windows for ingress monitoring and for the declaration of ingress events. For example, this location may be a communications gateway near or at the subscriber location. The map can also be transmitted to the head-end or other location in the network where it can be used by a network management system to determine the status of the return path network, isolate faults, and generate work orders to send craft to a residence.
Furthermore, this characterization may only occur at a test point in the network, or at a head-end in the network. For example, the characterization may occur at a telephone test point (TTP) in the network, or a Cable Modem Termination System (CMTS) at the head-end.
Although this invention has been illustrated by reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made that clearly fall within the scope of the invention. The invention is intended to be protected broadly within the spirit and scope of the appended claims.
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The present invention encompasses a method and apparatus for detecting and characterizing one or more ingress events in the return band and creating a time/frequency map based on the detection of the ingress events. The time/frequency map is further characterized by marking frequency bands with ingress level above a predetermined threshold with a “1”. The time/frequency time map may be used to determine when and which return frequency band has exceeded a predetermined threshold, and to distinguish between a narrowband ingress event and a wideband ingress event. When such characterization has been made, the return path may be attenuated or disconnected at a communications gateway device located at or substantially near the subscriber location. By disconnecting the return path or attenuating the return path signal at or near the subscriber location, the ingress may be reduced and locations which are the cause of severe ingress may be effectively isolated. This allows for a high degree of reliability to be maintained on the return path, and ensures that the critical services such cable telephony may be provided with increased customer satisfaction.
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CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of our co-pending application Ser. No. 694,903, filed June 10, 1976.
BACKGROUND OF THE DISCLOSURE
Our invention relates to cells consisting of hemoglobin encapsulated in lipids and more especially phospholipids and to the method of making such synthetic cells. These cells are characterized by comparable O 2 --CO 2 conjugation and transference to that of naturally occurring red blood cells. Furthermore, our synthetic cells are of such small size and flexibility to readily pass through mammalian capillary systems where such O 2 --CO 2 transfer takes place. Another, most desirable feature of our cells is that their use introduces no foreign matter to the recipient.
Our synthetic cells, in terms of oxygen carrying capability, function very similarly to normal mammalian red blood cells and accordingly in suspension offer substantial utility as a transfusion liquid. Such cells appear as acceptable to the mammalian host as are natural such cells, function in substantially the same manner and should be metabolized and excreted as are naturally occurring cells.
As is known to those skilled in this art, hemoglobin is a conjugated protein having a prosthetic group -- heme -- affixed to the protein, globin. It is the red coloring matter of blood and is found, contained, in the red blood cells. Its essential utility stems from its ability to unite in loose combination with atmospheric oxygen to form oxyhemoglobin. In mammals this occurs in the capillaries adjacent the lung alveoli to produce so-called oxygenated blood. This is carried in the arterial system to the tissues where a portion of the oxygen is released and then the venous blood, partially depleted in oxygen, is returned to the lungs for further oxygenation.
As further background we note that heme is an iron porphyrin, i.e., the union of iron with four pyrrole groups. The iron is basically in the ferrous state. Hemoglobin is usually designated as ##STR1##
Thus hemoglobin is a tetramer consisting of four sub-units; each sub-unit is a combination of a polypeptide chain, which is the protein or globin part of hemoglobin, and a heme. The latter is the functional unit or active site to which oxygen may be bound.
Whole blood, especially human, when drawn for transfusion purposes, is considered to have a storage life of 21 days. By present regulation, such blood 21 days old must be discarded and no longer used for blood transfusion. As a practical matter upon the passage of such time, the red cells break down thus making the old blood substantially useless for its intended purpose. However, such "old blood" still contains useful, functional hemoglobin and can be used as the starting material in the preparation of the present cells.
In distinction to the aging problem -- 21 days -- encountered with whole, natural blood, we find that the present cells when appropriately buffered, have quite an extended, useful, shelf life, as is noted below.
Our synthetic hemoglobin cells offer another advantage -- because of how they are made they can be considered to be in the class of universal donor. Whole blood for transfusion purposes must be typed and extreme care taken to assure compatability with the blood type of the recipient. This is not the case with the present cells. Our starting material for encapsulation is what is commonly referred to as "stroma-free" hemoglobin. This is hemoglobin free of the cell membranes or membrane fragments of the red blood cells but having associated therewith the normal cell components, such as diphosphoglycerate and carbonic anhydrase, required for O 2 --CO 2 exchange. The membranes of natural erythrocytes contain many different proteins and it is such protein which necessitates blood-typing. The membranes of our synthetic cells are essentially formed of universally present (i.e., in the mammal) lipids and the like which are not subject to antigenic reactions of proteins.
As further background to our invention, we note that the separation of red blood cells from whole blood is an old, established common practice. And the separation of hemoglobin from its associated red cells by a multitude of techniques is similarly well-known. Such two known categories of techniques represent the starting points in forming the hemoglobin cells of this invention.
As further background we also note that some workers have been investigating the use of cell-free hemoglobin solutions as natural blood substitutes. These solutions suffer the disadvantage of being rapidly excreted by the body and thus really do not accomplish their intended purpose for anything but the shortest of times. In distinction to this the present lipid encapsulated hemoglobin cells will be retained by the body for extended and more useful periods.
We also note that prior workers have formed what are generically referred to as liposomes.
Among the prior patents we note the following:
Bower, U.S. Pat. No. 2,527,210 is directed to a hemoglobin solution wherein a freezing-thawing technique is used to destroy the red cell membranes.
Childs, U.S. Pat. No. 3,133,881 discloses a centrifugation method which may be employed to separate red cells from the other constituents of whole blood.
Van Dyck et al., U.S. Pat. No. 3,351,432 is directed to the washing and reconstituting of red blood cells and Ushakoff, U.S. Pat. No. 3,418,209 to making red cells storable by a combination with a glycerin solution. Similarly, Ilg, U.S. Pat. No. Re. 27,359 is directed to the washing of red cells.
Bonhard, U.S. Pat. No. 3,864,478 discloses another method of making a hemoglobin solution.
The prior art teachings in no way suggest or hint at the lipid encapsulation of hemoglobin to form the present synthetic cells nor the benefit or utility of such cells. The similarity of the present synthetic cells to normal red blood cells in terms of oxygen carrying capability is unexpected.
Accordingly, a principal object of our invention is to provide lipid encapsulated hemoglobin -- synthetic erythrocytes -- and a method for their manufacture. How this is accomplished is set out as this description proceeds.
DETAILED DESCRIPTION
In practicing our invention, hemoglobin is first separated from its associated red blood cell membranes. The basis starting material herein as noted above, is stroma-free hemoglobin; this is the material which we subsequently encapsulate in lipid. We can start with relatively freshly drawn blood which contains a vast majority of viable red blood cells through blood drawn, e.g., 21 days previously or more, wherein a substantial proportion of the red cells no longer are viable. It is important to thoroughly separate the hemoglobin from its natural cell membranes to eliminate the above-noted protein reactions and other adverse reactions in the recipient.
There are numerous known procedures for separating hemoglobin from blood. First the red cells are separated from the plasma constituent by centrifugation or the like. The residue consists of both broken and unbroken red blood cells. By freeze-thawing or controlled osmotic lysis we rupture the remaining cell membranes, although other techniques may be employed, and then by filtration or the like we produce stroma-free hemoglobin solution. Care should be taken to avoid bacterial contamination and small quantities of suitable antibiotic or bacteriostatic agents such as gentamycin and tetracycline or the like may be added to the stroma-free hemoglobin. The concentration of hemoglobin and other constituents may be adjusted as desired.
The resulting hemoglobin solution is then encapsulated in naturally occurring lipids to form synthetic liposome cells. Such cells are typically 0.1 to 10 microns in their largest dimension. We believe that the lipid membrane is approximately two molecules thick.
In the present specification and claims the term "liposome" is used. By this is meant a capsule wherein the wall or membrane thereof is formed of lipids, especially phospholipid, with the optional addition therewith of a sterol, especially cholesterol.
In the preferred method hereof a thin lipid film is first formed on the interior surface of a container. In the laboratory such container is usually a flask of the round bottom type. A small amount of lipid in an organic solvent is placed in the flask and it is both shaken and spun to deposit a thin lipid film on the interior surface. Such film is permitted to dry. Then a small amount of the stroma-free hemoglobin solution is deposited in the flask. While other encapsulation techniques may be employed we prefer the following:
The flask is placed in a water bath maintained at 37° C. and the bath subjected to ultrasound at a frequency of 50,000 Hertz. In the presence of the hemoglobin solution and as a result of such mixing, the lipid material forms a continuous membrane about the hemoglobin solution and forms the cells of the present invention. The cells are then separated from the extracellular hemoglobin solution and suspended in an appropriate carrier liquid.
The film forming materials useful herein are selected from the group phospholipid generically. Representative of the useful phospholipids are synthetic and naturally-occurring lecithins, cephalins and sphingomyelins. Among such phospholipids the following materials exemplify, but are not exhaustive of the herein useful materials: phosphatidic acid, phosphatidyl serine, phosphatidyl inositol, phosphatidyl choline and phosphatidyl ethanolamine.
In addition to the use of phospholipid alone, we find that the use therewith of a sterol compound such as cholesterol greatly enhances those properties of the cell membrane that are desirable for the present application.
We prefer to use both cholesterol and one or more phospholipids together as the encapsulating material. We have found that a suitable encapsulant is 3 parts (by weight) lecithin to 1 part cholesterol. In the examples presented below this is referred to as the "3:1 material," although a "2:1" mixture of lipids would be expected to be equally suitable.
As to the hemoglobin solution as used herein, we prefer a solution containing ions normally present in plasma. However, other ions may be present. The pH is preferably 7.4 and the solution is preferably isoosmotic with normal plasma.
In order to prepare the encapsulating film, the cholesterol/phospholipid is first dissolved in an inert, highly volatile organic liquid such as chloroform. This is evaporated to leave the film on the flask wall.
Examples of how the present cells are produced are as follows:
EXAMPLE 1
60 mg of the 3:1 material was dissolved in 30 ml of reagent grade chloroform in a 1-liter round bottom flask under sterile conditions. Temperature was 25° C. The material was swirled around the flask walls under vacuum for approximately 15 minutes and a thin, transparent film was formed, coating the bottom two-thirds of the flask. Into such coated flask was then deposited 10 ml of hemoglobin solution containing 16 gram percent of hemoglobin as well as other normal soluble intracellular components of red blood cells. Such solution had a pH of 7.4 and was isoosmotic with normal plasma. The flask was then immersed up to its neck in a water bath maintained at 37° C. and ultrasound at a frequency of 50 KHz was applied through the bath for 15 minutes. There resulted 10 ml of encapsulated hemoglobin dispersion having a particle size spectrum ranging between 0.1 and 10 microns. This dispersion was washed three times with normal saline by centrifugation and decantation to produce the final product.
Any unencapsulated hemoglobin may be utilized in a subsequent encapsulation.
EXAMPLE 2
14.4 mg of cholesterol, 43.2 mg of lecithin ex ovo, and 2.4 mg of phosphatidic acid were dissolved in 25 ml of reagent grade chloroform in a 1-liter round bottom flask under sterile conditions. Temperature was 25° C. The material was swirled around the walls, under vacuum, for approximately 15 minutes and a thin, transparent film was formed, coating the bottom two-thirds of the flask. Into such coated flask was then deposited 10 ml of hemoglobin solution containing 15.7 gm percent hemoglobin (plus other normal soluble intracellular components) in isotonic saline. The rest of the procedure follows Example 1.
EXAMPLE 3
20 mg of cholesterol and 100 mg of lecithin ex ovo were dissolved in 25 ml of reagent grade chloroform in a 1-liter round bottom flask under sterile conditions. The rest of the procedure follows Example 1, with the exception that the hemoglobin solution contained 14.71 gm percent hemoglobin (plus other normal soluble intracellular components) in isotonic saline.
EXAMPLE 4
30 mg of cholesterol, 80 mg of lecithin ex ovo, and 10 mg of phosphatidyl serine were dissolved in 25 ml of reagent grade chloroform in a 1-liter round bottom flask under sterile conditions. The rest of the procedure follows Example 3.
EXAMPLE 5
The procedure follows Example 1, with the exception that the hemoglobin solution contained 22 gm percent hemoglobin (plus other normal soluble intracellular components) in isotonic saline.
The encapsulated hemoglobin cells resulting from Example 1 were tested as follows:
Gas mixtures consisting of varying proportions of oxygen, nitrogen, and carbon dioxide, at one atmosphere total pressure, were equilibrated with samples of the present encapsulated hemoglobin, and the relative oxygen saturation of the hemoglobin was determined by spectrophotometry. The results were as follows:
______________________________________pO.sub.2 (mm Hg) pCO.sub.2 (mm Hg) % O.sub.2 saturation______________________________________10 44 14.920 45 28.730 42 46.340 42 62.350 41 72.060 41 85.770 40 89.590 40 90.7______________________________________
These results, obtained at 22° C. and a pH of 6.35, closely follow what would be obtained for normal whole blood under the same conditions.
In the practice of the present invention we prefer to use ultrasonic energy as the means for encapsulation. However, other means of providing vigorous stirring of the hemoglobin-lipid-cholesterol may be employed. Intimate mixing of the hemoglobin and cell membrane material is required.
The resulting cell size can be fairly closely controlled, the aim of course being to have cells capable of unhindered capillary passage. Cell size is dependent upon factors such as: temperature, viscosity, stirring frequency, interfacial tension as between membrane material and the aqueous phase hemoglobin being encapsulated, and other physical properties. Lower stirring energy levels than we have used would likely result in reduced cell forming efficiency.
It is interesting to note that cell size in the present invention is substantially self-governing. Cells larger than 10 microns appear somewhat unstable and break down into smaller units. And, of course, liposomes too big for intended use may readily be filtered out.
There is another aspect of the present hemoglobin liposomes that should be noted. Normally occurring red blood cells are characterized by slight surface electronegativity commonly measured in terms of "zeta potential." Under conditions comparable to those used in the oxygenation study described above, red blood cells are characterized by zeta potentials in the range of -8 to -17 millivolts. By controlling the relative proportions of certain cell membrane forming materials hereof (e.g., the electronegative phospholipids such as phosphatidic acid or its functional equivalent, dicetyl phosphate) we can vary the zeta potential measurements of our synthetic cells across this range and in fact have found that cells formed from Example 3 have a zeta potential of -22 millivolts. The various phospholipids used herein are characterized by varying electronegativities. Such electronegativity in both natural and our synthetic erythrocytes is believed to be physiologically significant inter alia to both keep the cells separated from each other in the blood stream and from the blood vessel walls. Further, the tendency toward agglutination of synthetic erythrocytes may be reduced by the addition of small amounts of albumin to the stroma-free hemoglobin prior to encapsulation.
In the present hemoglobin liposomes the cell membrane is preferably a bilayer although multilayers may be used. Within the limit of providing adequate hemoglobin encapsulation, it is preferred that the cell wall be as thin as possible to enhance O 2 --CO 2 exchange.
It will be evident to those skilled in the art associated with the present invention that the present hemoglobin liposomes essentially contain materials naturally occurring in the mammalian host. Such cells may be used for blood transfusion purposes (e.g., in isotonic saline or Krebs-Ringers solutions or in synthetic plasma materials such as dextran or hydroxyethyl starch solutions and the like) with a comparative long life in the body of the host, as compared with free hemoglobin, and also will be naturally metabolized for subsequent excretion. Even more specifically, synthetic erythrocytes of the invention may be stored, "packed," re-constituted and administered according to standardized techniques well known in the art of "banking" and transfusing natural erythrocytes. In this respect, see, e.g., "Blood Banking and the Use of Frozen Blood Products" (CRC Press, Cleveland, Ohio, 1976) pp. 38-39, 107-110, 360-361; "Transfusion of Blood Preserved by Freezing" (Igaku Shoin, Tokyo, 1973) pp. 28-44; and "Quality Control in Blood Banking" (John Wiley & Sons, New York, New York, 1974) pp. 137-144; 197-198.
Furthermore, our cells appear sturdier than normal red blood cells which should prove useful in extracorporeal functions such as in conjunction with heart-lung machines or artificial kidney machines. In addition to this, such synthetic cells are expected to have a reasonably good shelf life beyond the 21 days of whole blood. At a pH of 6.5 we found that after two and six weeks respectively of storage there still remained 50% and 25% of active hemoglobin in our liposomes. At a pH of 7.4 the results would be expected to be better.
The following are examples of in vivo administration of synthetic erythrocytes of the invention which were prepared using a synthetic lecithin (about 13 parts by weight), cholesterol (about 5 parts) and phosphatidic acid (about 2 parts) as the encapsulating material.
EXAMPLE 6
The material administered contained 25% cells by volume (Hct) suspended in 1 liter of Krebs-Ringers solution (pH 7.4). The cells suspended contained 10 gm hemoglobin/100 cc (i.e., 10 gm percent). A total of 8 to 10 cc of solution was administered to a rat in two batches -- 4 cc of blood was removed and 4 cc of solution was infused and this process was repeated -- effectively replacing about 40% of the animal's blood volume. The animal survived for about 30 minutes and upon attempting to remove an additional 10 cc of blood, the rat was inadvertently killed. Close inspection of tissue evidenced no adverse immunological effects.
EXAMPLE 7
The material administered contained 30-40% by volume of cells, containing 12 gm percent hemoglobin, in Krebs-Ringers solution (pH 7.4) including an antibiotic. The material was administered to 4 rats with the following results.
(a) Poor technique was employed in administering the material to the first rat, and resulted in the animal's death.
(b) The cannula employed to administer the material to a second rat pulled out inadequately and the animal bled to death.
(c) In the third rat, approximately 16 cc of the material -- about 100% of the entire blood volume -- was exchanged. The animal died of pulmonary edema about 30 minutes after the start of the transfusion. It is believed that the transfusion process was probably at fault. The blood was withdrawn about 4 cc at a time and the material was infused directly into the right heart through the jugular vein. The probable cause of death was a weakening of the heart as a result of the administration technique employed.
(d) A total of 6 cc of material (equivalent to about 4 units of blood in a human patient) was administered intravenously without withdrawal of blood. The animal was a long-term survivor.
EXAMPLE 8
The material employed was a 45% by volume suspension of cells (11.45 gm percent hemoglobin) in Krebs-Ringers solution (pH 7.4) with an antibiotic. The material was administered by a technique wherein an infusion pump was employed to effect simultaneous withdrawal of blood from the femoral artery and infusion of the material into the femoral vein. A total of 22 cc (approximately 150% of blood volume) was administered over a period of 55 minutes at which time the animal died, apparently of disseminated intravascular coagulation -- probably the result of stromal lipid contamination of the hemoglobin.
EXAMPLE 9
The material administered consisted of a 7.5 gm percent hemoglobin in Krebs-Ringers solution to which 5% by weight albumin was added. Synthetic erythrocytes were prepared by the film method above described, using one part cholesterol, one part synthetic lecithin, and one part dicetyl phosphate as a substitute for phosphatidic acid. After sonication, the particles were filtered and those having a diameter in excess of about 0.8 microns were discarded. The hematocrit of the final solution was roughly 20. About 5 cc of the material (equivalent to 21/2 units of blood in a human patient) was intravenously administered to a rat and the animal was a long-term survivor.
It will be understood that various modifications and variations may be expected without departing from the spirit or scope of the novel concepts of our invention.
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Synthetic erythrocytes. Hemoglobin is encapsulated in lipid materials to form cells which are typically 0.1 to 10 microns in their greatest dimension. Preferably cholesterol and one or more phospholipids are included in the cell membrane. The lipid membrane is of such character and thinness that O 2 --CO 2 transfer thereacross is readily accomplished. The preferred encapsulation process utilizes ultrasonic energy.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 12/676,594, now U.S. Pat. No. 8,193,573 which is a United States National Stage Application filed under 35 U.S.C. §371 of PCT Patent Application No. PCT/US2008/075261 filed on Sep. 4, 2008, which claims the benefit of and priority to U.S. Provisional Patent Application No. 60/970,223 filed on Sep. 5, 2007, the disclosures of all of which are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
The disclosed embodiments relate generally to repairing semiconductor devices, and more particularly, to annealing packaged nonvolatile semiconductor memory devices to improve memory endurance or other characteristics that change with usage.
BACKGROUND
Nonvolatile semiconductor memory devices such as flash memory can only perform a limited number of write and erase cycles before memory cells lose the ability to store data properly. Specifically, device operation generates defects, such as defects in the tunneling insulator, that trap charge, thereby degrading the ability of memory cells to store data. For example, a flash memory device may be limited to 10,000 write cycles or fewer. The time needed to program or erase a memory cell may also degrade with usage and the device is specified for the worst case characteristics.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are cross-sectional views of a semiconductor package in accordance with some embodiments.
FIG. 1C is a cross-sectional view of a semiconductor package containing multiple semiconductor devices and a heating element in accordance with some embodiments.
FIG. 1D is a cross-sectional view of a semiconductor package containing multiple semiconductor devices and multiple heating elements in accordance with some embodiments.
FIG. 2 is a block diagram of an electronic system that includes a semiconductor package in accordance with some embodiments.
FIGS. 3A and 3B are cross-sectional views of a module in accordance with some embodiments.
FIG. 3C is a plan view of a module in accordance with some embodiments.
FIG. 4 is a block diagram of an electronic system that includes a module in accordance with some embodiments.
FIG. 5 is a flow diagram illustrating a method of repairing a nonvolatile semiconductor memory device in accordance with some embodiments.
Like reference numerals refer to corresponding parts throughout the drawings. For visual clarity and ease of description, cross-hatching has been omitted for various elements in the cross-sectional views.
DESCRIPTION OF EMBODIMENTS
In some embodiments, a method of repairing a nonvolatile semiconductor memory device includes monitoring an event indicator associated with the nonvolatile semiconductor memory device. An event is then detected with the event indicator. Finally, in response to detecting the event, the nonvolatile semiconductor memory device is annealed.
In some embodiments, a semiconductor apparatus is self-annealing, wherein annealing is performed in a normal operating environment of the apparatus. The apparatus includes a nonvolatile semiconductor memory device; a heating element thermally coupled to the memory device, to anneal the device; a first set of electrical contacts electrically coupled to the memory device, to provide signals to the memory device; and a second set of electrical contacts electrically coupled to the heating element, to provide power to the heating element.
Reference will now be made in detail to various embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the disclosure herein. However, it will be apparent to one of ordinary skill in the art that the described embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the embodiments.
The term semiconductor package, or simply package, as used herein, refers to a component, to be mounted on a substrate (such as a printed circuit board), containing one or more semiconductor die and providing electrical connections between the die and the substrate. The term memory module, or simply module, as used herein, refers to a substrate (i.e. printed circuit board), on which are mounted packages containing semiconductor memory devices (i.e., semiconductor memory die), configured to be electrically coupled to (e.g., plugged into) another substrate such as a motherboard.
Operation of nonvolatile semiconductor memory devices, such as flash memory, induces defects that trap charge or provide leakage paths for stored charge and thereby shift the threshold voltages of transistors in corresponding memory cells. This degrades the ability of the memory cells to receive and store data written to the cells. Over time, the voltage margin in the cells degrades to the point where ones written to the cells cannot be distinguished from zeros written to the cells, thereby resulting in memory errors when cells are read, i.e., their stored values do not match the values previously written to the cells.
The term flash memory as used herein includes flash memory semiconductor devices with floating gates and/or charge-trapping memory semiconductor devices such as SONOS (semiconductor-oxide-nitride-oxide semiconductor), TANOS (Ta/Al2O3/SiN/SiO2/Si), nanocrystal memory device, and related technologies such as NAND, NOR, synchronous versions of both, EEPROMS, etc.
To improve the endurance and lifetime of flash memory semiconductor devices, the devices may be repaired through an annealing process to passivate and/or eliminate defects induced by device operation. The term annealing as used herein refers to heating a device to a sufficient junction temperature for a sufficient period of time to reduce or eliminate defects. For example, this period of time may be from seconds up to minutes, but in less than an hour. The term junction temperature as used herein refers to the temperature of the device at the active layers of the device, such as in the memory cells of a flash memory semiconductor device. The term self-annealing, as used herein, refers to an apparatus configured to be annealed in situ in its normal operating environment between periods of operation.
In some embodiments, a flash memory semiconductor device that has been packaged, assembled in a system, and used in operation, may be annealed using a heating element that is thermally coupled to the device. For example, the heating element may be a component within the semiconductor package containing the device or may be externally mounted to the package such that heat conducts from the heating element to the package, and thereby to the device, when power is supplied to the heating element.
In some embodiments, to anneal a device, the heating element is heated to an annealing temperature corresponding to a junction temperature of between 200° C.-300° C. In other embodiments, the heating element is heated to an annealing temperature corresponding to a junction temperature of between 200° C.-250° C. In still further embodiments, the heating element is heated to an annealing temperature corresponding to a junction temperature of between 250° C.-300° C. Finally, even lower temperatures, such as 150° C.-200° C., have been shown to be useful for in-situ annealing.
In some embodiments, the maximum annealing temperature of the heating element is limited by characteristics of the semiconductor package containing the device or of the printed circuit board to which the package is coupled. For example, the temperature is limited by the reflow temperature of solder used as a packaging material or by substrate glass transition temperatures.
FIG. 1A is a cross-sectional view of a semiconductor package 100 in accordance with some embodiments. The package 100 contains a nonvolatile semiconductor memory device 102 , such as a flash memory die. In some embodiments, the device 102 is a die containing SONOS memory. The device 102 is electrically coupled to a substrate 110 through wirebonds 112 . Vias 116 and electrical traces 118 in the substrate 110 provide electrical pathways between wirebonds 112 and respective solder balls 120 - 1 . The solder balls 120 - 1 serve as electrical contacts to provide power and ground connections, as well as signals to the device 102 .
The device 102 is mounted on a heating element 106 with a thermally conductive adhesive layer 104 . For example, the adhesive layer 104 may be thermally conductive tape or film, such as tape or film with a thermal conductivity at a minimum of about 1 W/mK. Alternatively, the adhesive layer 104 is a thermal paste or adhesive. In some embodiments, a spacer (e.g., a silicon spacer with a thickness of approximately 25 to 50 um) is included between the device 102 and the heating element 106 .
In some embodiments, the heating element 106 is a thin-film heater. Exemplary materials from which the thin-film heater is manufactured include polyimide, silicone rubber, or a ceramic material such as mica. Examples of suitable thin-film heaters include a number of heaters manufactured by MINCO (www.minco.com), like its HTK04 All-Polyimide (AP) Heaters, or its HTK05 Polyimide Thermofoil Heaters (where these heaters have to be customer designed to fit the package profile). An alternative heating element is a thick-film heater like that manufactured by CHROMALOX and WATLOW.
The heating element 106 is mounted on the laminate substrate 110 with an adhesive layer (e.g., tape or film) 108 , which in some embodiments is not thermally conductive. For example, non-conductive tape or film 108 may have a thermal conductivity of approximately 0.2 W/mK. The heating element is electrically coupled to solder balls 120 - 2 through electrical connections (e.g., wires with wire bonding on slightly larger heating element 106 ) 114 and through vias 117 and/or traces 119 in the substrate 110 . The solder balls 120 - 2 serve as electrical contacts to provide power to the heating element. In some embodiments, the electrical connections 114 include a power connection and a ground connection.
The solder balls 120 thus include two sets of contacts: a first set of contacts (i.e., solder balls 120 - 1 ) to provide signals to the device 102 and a second set of contacts (i.e., solder balls 120 - 2 ) to provide power to the heating element 106 . It should be noted that the contacts may be electrical connections other than solder balls.
In some embodiments, the package 100 includes a temperature sensor to monitor the annealing temperature. In some embodiments, the temperature sensor is electrically accessible from outside of the package. For example, the temperature sensor provides feedback to a controller that regulates power provided to the heating element 106 , to maintain the annealing temperature at a predefined temperature or within a predefined range. Alternatively, the temperature sensor writes temperature readings to a memory accessible by a controller. In some embodiments, the temperature sensor is integrated into the device 102 and is electrically coupled to the controller or memory through one or more wirebonds 112 (or metal balls or bumps 132 , as shown in FIG. 1B ), vias 116 , traces 118 , and solder balls 120 - 1 . In some embodiments, the temperature sensor is integrated into the heating element 106 and is electrically coupled to the controller or memory through one or more electrical connections 114 , vias 117 , traces 119 , and solder balls 120 - 2 . In some embodiments, the temperature sensor is a discrete component of the package 100 .
The device 102 , heating element 106 , and wirebonds 112 are encased in molding compound 122 . In some embodiments, the molding compound 122 has a sufficiently high glass transition temperature to ensure that annealing does not compromise the integrity of the casing formed by the molding compound 122 .
Having the heating element 106 in the package 100 allows the package to be self-annealing: the device 102 may be annealed in situ in the package 106 in its normal operating environment, after a period of operation, to reduce or eliminate defects. For example, the device 102 may be annealed after the package 100 has been mounted on a printed circuit board and operated for a period of time in an electronic system.
FIG. 1B is a cross-sectional view of a semiconductor package 130 in accordance with some embodiments. In the package 130 , the device 102 is coupled to the substrate 110 using flip-chip bonding: metal balls or bumps 132 provide electrical connections between the device 102 and the substrate 110 . Vias 116 and traces 118 in the substrate 110 provide electrical pathways between the metal balls or bumps 132 and respective solder balls 120 - 1 . The heating element 106 is mounted on the device 102 with a thermally conductive adhesive layer 104 and is electrically coupled to solder balls 120 - 2 through electrical connections 114 and through vias 117 and traces 119 in the substrate 110 . The device 102 , heating element 106 , and electrical connections 114 are encased in molding compound 122 . In some embodiments, underfill material fills the space surrounding the metal balls or bumps 132 between the device 102 and the substrate 110 .
Packages 100 and 130 , which are shown as ball-grid array (BGA) packages with solder balls 120 , are merely exemplary packages in which a heating element is thermally coupled to a nonvolatile semiconductor memory device. In some embodiments, instead of a BGA, the package may include a pin-grid array (PGA), a land-grid array (LGA), or metal leads. In some embodiments, instead of a laminate substrate, the device and/or heating element may be mounted on some other suitable substrate or on the paddle of a leadframe. In some embodiments, instead of being encased in molding compound, the device and heating element may be contained in some other suitable housing, such as a ceramic casing or a metal cover attached to the heating element 106 with thermally insulating film or tape.
In some embodiments, in addition to a nonvolatile semiconductor memory device and a heating element, a package may contain one or more additional semiconductor devices. The additional semiconductor devices may include additional nonvolatile semiconductor memory devices (e.g., additional flash memory devices) and may include other types of semiconductor devices, such as volatile memory devices (e.g., DRAM or SRAM). In some embodiments, the semiconductor devices are stacked in the package. For example, a heating element may be stacked between a nonvolatile semiconductor memory device and an additional device. The package also may contain additional heating elements to anneal the additional devices. In some embodiments, the additional heating elements are interleaved with the semiconductor devices in a stack.
FIG. 1C is a cross-sectional view of a semiconductor package 140 containing two semiconductor devices 102 and a heating element 106 in accordance with some embodiments. The devices 102 are configured in a stack, with the heating element 106 interleaved between the devices. Thermally conductive adhesive layers 104 conduct heat from the heating element 106 to the devices 102 .
The devices 102 are electrically coupled to solder balls 120 - 1 through wirebonds 112 or metal balls or bumps 132 , and through vias 116 and traces 118 . While FIG. 1C shows a flip-chip device 102 - 1 and a wirebonded device 102 - 2 , in some embodiments both devices 102 - 1 and 102 - 2 are wirebonded. The heating element 106 is electrically coupled to solder balls 120 - 2 through electrical connections 114 and through vias 117 and/or traces.
FIG. 1D is a cross-sectional view of a semiconductor package 150 containing multiple semiconductor devices 102 and multiple heating elements 106 in accordance with some embodiments. The devices 102 and heating elements 106 are interleaved in a stack. A respective device 102 is mounted on a heating element 106 below the respective device 102 with a thermally conductive adhesive layer 104 . A respective heating element 106 is mounted on a device 102 below the respective heating element 106 , or on the substrate 110 , with die attach tape or film 108 .
The devices 102 are electrically coupled to solder balls 120 through wirebonds 112 and through vias 116 and traces 118 , as shown in FIGS. 1A-1C . Furthermore, in some embodiments wirebonds 124 electrically couple two devices 102 . For example, wirebonds 124 may serially connect successive devices 102 . The heating elements 106 are electrically coupled to solder balls 120 - 2 through electrical connections 114 and through vias 117 and traces 119 , as shown in FIGS. 1A-1C .
FIG. 2 is a block diagram of an electronic system 200 that includes a self-annealing semiconductor package 202 in accordance with some embodiments. Examples of self-annealing semiconductor packages 202 include packages 100 , 130 , 140 , and 150 ( FIGS. 1A-1D ). The system 200 may be any system that uses nonvolatile semiconductor memory such as flash memory. In some embodiments, the system 200 is a mobile application, such as a cell phone, personal digital assistant (PDA), or music player.
The package 202 includes a nonvolatile semiconductor memory device 102 and a heating element 106 . In some embodiments, the package 202 includes a temperature sensor 204 . The temperature sensor 204 may be integrated into the device 102 . Alternatively, the temperature sensor may be integrated into the heating element 106 . The device 102 also may include error correction coding (ECC) circuitry to detect memory errors.
The package 202 is coupled to a controller 208 (e.g., a microprocessor or microcontroller) via signal lines 224 . The controller 208 is configured to determine when to anneal the device 102 and to initiate the annealing process. For example, the controller 208 instructs a power supply 222 to provide power to the heating element 106 via electrical connections 226 , thereby heating the heating element.
In some embodiments, the controller 208 includes a memory endurance monitor 210 that monitors a memory endurance indicator for the device 102 to determine when to anneal the device. The monitor 210 determines whether the indicator exceeds a predefined limit and, in response to determining that the indicator exceeds the limit, initiates the annealing process.
In some embodiments, the memory endurance monitor 210 includes an erase cycle counter 212 to record a count of erase cycles performed by the device 102 . The monitor 210 compares the recorded count against a predefined count to determine whether to anneal the device 102 . The predefined count is determined, for example, by characterizing the nonvolatile memory cells of the type (i.e., of the cell design and process technology) used in the device 102 to determine a maximum number of erase cycles that the device 102 reliably can perform. In some embodiments, after the device 102 has been annealed, the recorded count is reset to zero. The erase cycle counter 212 then records a count of subsequent erase cycles performed by the device 102 . The monitor 210 compares the count of subsequent erase cycles against the predefined count, to determine whether to anneal the device 102 again. Alternately, instead of resetting the recorded count to zero, the erase cycle counter 212 continues to increment the recorded count, and the monitor 210 determines that the device is to be annealed again when the recorded count reaches an integer multiple of the predefined count.
In some embodiments, the memory endurance monitor 210 includes a programming step counter 214 to record a number of programming steps performed to program the device 102 . The monitor 210 compares the recorded number of programming steps against a predefined number to determine whether to anneal the device 102 . The predefined number may be defined as a predetermined percentage or number of steps above a baseline number of steps.
In some embodiments, the memory endurance monitor 210 includes error detection circuitry 216 to record a count of errors detected for the device 102 . The monitor 210 compares the recorded count of errors against a predefined number to determine whether to anneal the device 102 . Alternatively, ECC circuitry 206 in the device 102 records a count of errors and reports the recorded count to the controller 208 or signals the controller 208 when the count exceeds a predefined number. In some embodiments, after the device 102 has been annealed, the recorded count of errors is reset to zero. The error detection circuitry 216 then records a subsequent count of errors and the monitor 210 compares the subsequent count of errors against the predefined number, to determine whether to anneal the device 102 again.
In some embodiments, the memory endurance monitor 210 includes a use monitor 218 to record a period of use for the device 102 . The use monitor 218 may include a clock 219 , or may be coupled to a clock external to the use monitor 218 . The monitor 210 compares the recorded period of use against a predefined length of time to determine whether to anneal the device 102 . In some embodiments, after the device 102 has been annealed, the recorded period of use is reset to zero. The use monitor 218 then records a subsequent period of use and the monitor 210 compares the subsequent period of use against the predefined length of time, to determine whether to anneal the device 102 again. Alternately, instead of resetting the period of use to zero, the user monitor 218 continues to record the period of use and the monitor 210 determines that the device is to be annealed again when the recorded period of use reaches an integer multiple of the predefined length of time.
In some embodiments, the device 102 can only be annealed a specified number of times. The controller 208 records the number of times that the device has been annealed and will not initiate the annealing process if the recorded number of times equals or exceeds the specified number of times.
In some embodiments in which the system 200 is a mobile application or other type of battery-powered application, the controller 208 will delay annealing until the system 200 is plugged into a power supply to charge the battery. The controller 208 thus assures that sufficient power is available for annealing.
In some embodiments in which the system 200 is a mobile application or other type of battery-powered application, the controller 208 will anneal the system whenever 200 is plugged into a power supply to charge the battery. This opportunistic annealing does not rely upon memory endurance monitors. Rather it only senses when power is available for annealing.
In some embodiments, during annealing, the controller 208 monitors an annealing temperature as reported by the temperature sensor 204 . The controller adjusts the power supplied to the heating element 106 to maintain the annealing temperature within a predetermined temperature range corresponding to a predetermined range of junction temperatures for the device 102 . For example, based on feedback from the temperature sensor 204 , the controller 208 instructs the power supply 222 to adjust the level of power supplied to the heating element 106 , to maintain the annealing temperature within the predetermined range. In other embodiments, instead of adjusting the level of power based on feedback, a predefined level of power is supplied to the heating element 106 .
The annealing process may corrupt data stored in the device 102 . Therefore, in some embodiments, the controller 208 copies the data stored in the device 102 into another memory 220 prior to annealing, and copies the data back into the device 102 upon completion of the annealing. The memory 220 may be any suitable memory device within or coupled to the system 200 . For example, the memory 220 may include one or more semiconductor memory devices or magnetic or optical disk storage devices within the system 200 . The memory 220 may include a memory stick or memory card inserted into the system 200 . The memory 220 may include memory in another system to which the system 200 is coupled, either directly or through a network (e.g., through the internet). For example, the data may be transferred to a computer to which the system 200 is coupled to charge or synchronize the system 200 . In another example, the data may be uploaded to a server and then downloaded to the device 102 upon completion of annealing.
In some embodiments, one or more of the above-identified functions performed by the controller 208 are implemented in software, and thus may correspond to sets of instructions for performing these functions. These sets of instructions, which may be stored in the device 102 or other memory 220 , need not be implemented as separate software programs, procedures or modules, and thus subsets of these sets of instructions may be combined or otherwise re-arranged in various embodiments.
FIGS. 1A-1D and FIG. 2 describe embodiments in which a heating element is housed within a package containing a nonvolatile semiconductor memory device to be annealed. However, in some embodiments, the heating element is external to the package. For example, an external heating element is thermally coupled to the exterior of a package (or several packages) mounted on a printed circuit board. In some embodiments, the printed circuit board is a motherboard or a circuit board coupled to a motherboard, such as a module (e.g., a single- or dual-inline memory module (SIMM or DIMM)) or daughtercard. In some embodiments, the printed circuit board includes a rigid substrate; in other embodiments, the substrate is flexible. In some embodiments, the heating element is a thin-film heater, as described with respect to heating element 106 .
FIG. 3A is a cross-sectional view of a module 300 in accordance with some embodiments. The module 300 is shown as a module (e.g., a DIMM) that includes packaged nonvolatile semiconductor memory devices 306 mounted on a laminate substrate 302 . A respective packaged device 306 includes a die containing nonvolatile semiconductor memory such as flash memory. In some embodiments, the respective device 306 includes a die containing SONOS memory. In some embodiments, the respective device 306 includes multiple die. The multiple die may include multiple die of nonvolatile semiconductor memory and may include other types of semiconductor devices, such as volatile semiconductor memory.
In the example of FIG. 3A , the packaged devices 306 are BGA-type packages, with solder balls 304 providing electrical and mechanical connections between the devices 306 and the substrate 302 . In some other embodiments, a packaged device may be a PGA- or LGA-type device or may include metal leads to provide electrical and mechanical connections between the device and the substrate.
Heating elements 310 are mounted on respective devices 306 . Thermal interface material 308 , such as thermally conductive tape, film, paste, or adhesive, conducts heat from a heating element 310 to a respective device 306 . Electrical connections (e.g., wires) 316 couple the heating elements 310 to the substrate 302 , thus providing power and ground connections to the heating elements 310 . (For clarity, FIG. 3A shows only a single electrical connection 316 for a corresponding heating element 310 .) The heating elements 310 allow the module 300 to be self-annealing: the devices 306 may be annealed on the module 300 after a period of operation, to reduce or eliminate defects.
Optional cover 314 is attached to the heating elements 310 through thermally insulating layers 312 . The layers 312 may include tape, film, paste, or adhesive. In some embodiments, the cover 314 is thermally insulating (e.g., plastic). Use of a thermally insulating cover helps to retain heat generated by the heating elements 310 , thereby reducing the power needed to reach the annealing temperature range and thus improving the efficiency of the heating elements 310 .
In the example of FIG. 3A , separate heating elements 310 are mounted on and, thereby, thermally coupled to respective packaged devices 306 . In some embodiments, however, a single heating element is thermally coupled to multiple packaged devices. Using a single heating element for multiple packaged devices reduces the number of components and simplifies assembly of the module.
For example, FIG. 3B shows a module 330 in which a single heating element 334 covers multiple packaged devices 306 on a respective side of the substrate 302 , in accordance with some embodiments. Thermal interface material 332 conducts heat from the heating element 334 to the devices 306 . Electrical connections 338 couple the heating element 334 to the substrate 302 . In some embodiments, the electrical connections 338 couple the heating element 334 to the external system, like a motherboard in PC system. The cover 314 is attached to the heating element 334 with a thermally insulating adhesive layer 336 .
FIG. 3C is a plan view of the module 330 in accordance with some embodiments. The heating element 334 and packaged devices 306 are shown with dashed outlines to indicate that they are beneath the cover 314 . The module 330 includes electrical contacts (i.e., edge fingers) 340 . In some embodiments, the electrical contacts 340 are compatible with a female socket on a motherboard, such that the module 330 can be plugged into the socket. The contacts 340 include a first set of contacts to provide signals to the packaged devices 306 and a second set of contacts to provide power to the heating element 334 . Traces and vias (not shown) in the substrate 302 route signals from the first set of contacts 340 to the solder balls 304 of respective packaged devices 306 and route power from the second set of contacts 340 to the electrical connections 338 of the heating element 334 .
For the modules 300 and 330 described above, the devices 306 to be annealed are mounted on both sides of the substrate. In some other embodiments, the devices to be annealed are mounted on a single side of a substrate. The heating element(s) may be mounted on either the same side or the opposite side of the substrate as the devices. In embodiments in which a heating element is mounted on the opposite side of the substrate as the device, the heating element is thermally coupled to the device through the substrate.
FIG. 4 is a block diagram of an electronic system 400 that includes a self-annealing module 402 in accordance with some embodiments. The module 402 includes a heating element 404 thermally coupled to a package 406 . The package 406 includes a nonvolatile semiconductor memory device 102 . In some embodiments, the module 402 corresponds to the module 300 or 330 of FIGS. 3A-3C and the heating element 404 corresponds to heating element 310 or 334 . The system 400 may be any system that uses nonvolatile semiconductor memory such as flash memory. In some embodiments, the system 400 is a mobile application, such as a cell phone, PDA, or music player. In some embodiments, the system 400 is a computer system, such as a notebook or desktop PC or a server.
The system 400 includes a controller 208 , memory 220 , and power supply 222 , which function as described for the system 200 ( FIG. 2 ). In some embodiments, the controller 208 , memory 220 , and/or power supply 222 are located on the module 402 along with the package 406 and heating element 404 .
FIG. 5 is a flow diagram illustrating a method 500 of annealing a nonvolatile semiconductor memory device in accordance with some embodiments.
An event (such as a memory endurance threshold) indicator is monitored ( 502 ) for a nonvolatile semiconductor memory device contained in a semiconductor package. In some embodiments the device corresponds to device 102 contained in package 202 ( FIG. 2 ) or in package 406 ( FIG. 4 ). In some embodiments, the event indicator is monitored by a controller (e.g., controller 208 ).
In some embodiments, monitoring the event indicator includes recording ( 504 ) a count of erase cycles performed by the device. For example, the erase cycle counter 212 in the controller 208 records a count of erase cycles performed by the device 102 .
In some embodiments, monitoring the event indicator includes recording ( 506 ) a count of errors detected for the device. For example, error detection circuitry 216 in the controller 208 records an error count for the device 102 .
In some embodiments, monitoring the event indicator includes recording ( 508 ) a number of programming steps performed to program the device. For example, the programming step counter 214 in the controller 208 records the number of programming steps performed to program the device 102 .
In some embodiments, monitoring the event indicator includes recording ( 510 ) a period of use of the device. For example, the use monitor 218 in the controller 208 records a period of use of the device 102 . Different definitions of the period of use are possible. For example, the period of use may be defined as a period of time for which the device has performed read and write operations, a period of time in which a system (e.g., 200 or 400 ) containing the device has been active, or a period of time since the system containing the device left the factory or was first activated.
In some embodiments, monitoring the event indicator includes determining whether the semiconductor device is receiving sufficient power for annealing to occur. For example, in mobile consumer electronics, such as MP3 players or cellular-telephones, the controller 208 or power supply 222 determines whether power is being received from an external charger plugged into a wall-outlet.
An event is then detected ( 512 ) (e.g., by the controller 208 ). For example, it is determined that the event indicator (e.g., memory endurance indicator) exceeds ( 512 ) a predefined limit or threshold. In some embodiments, it is ascertained that the recorded count of erase cycles exceeds ( 514 ) a predefined count. In some embodiments, it is ascertained that the recorded count of errors detected for the device exceeds ( 518 ) a predefined number. In some embodiments, it is ascertained that the recorded number of programming steps exceeds ( 518 ) a predefined number. In some embodiments, it is ascertained that the recorded period of use exceeds ( 520 ) a predefined length of time.
In response to detecting the event, the device is annealed ( 522 ). For example, it is determining that the memory endurance indicator exceeds the predefined limit. Annealing occurs, for example, by the controller 208 instructing the power supply 222 to supply power to the heating element 106 ( FIG. 2 ) or 404 ( FIG. 4 ), which is thermally coupled to the device.
In some embodiments, the annealing only occurs when an appropriate external physical event occurs. For example, if the nonvolatile semiconductor memory device is contained in a mobile consumer device, such as a MP3 player or cellular-telephone, and it is determined that annealing should occur, then annealing only occurs the next time that the device is coupled to an external power source, such as a charger plugged into a wall-outlet. This opportunistic annealing is useful given the limited power capability of some mobile consumer devices. Alternatively, annealing occurs even when the memory endurance monitor would not normally require annealing to occur, e.g., at predetermined intervals.
In some embodiments, an annealing temperature corresponding to a junction temperature of the device is monitored ( 524 ) (e.g., by a temperature sensor 204 ). In some embodiments, power provided to a heating element (e.g., 106 or 404 ) that is thermally coupled to the device is regulated ( 526 ) to maintain the annealing temperature within a predetermined range. For example, the controller 208 provides instructions to the power supply 222 to regulate power supplied to the heating element, based on feedback from the temperature sensor 204 . In some embodiments, the predefined range of annealing temperatures corresponds to a range of junction temperatures of 200° C. to 300° C., or 200° C. to 250° C., 250° C. to 300° C., or even in some instances as low as 150° C.-200° C.
In some embodiments, the device is annealed for a predetermined period of time. For example, the nonvolatile memory cells of the type (i.e., of the cell design and process technology) used in the device 102 are characterized to determine a period of time sufficient to anneal out defects at a given junction temperature or range of junction temperatures. The controller 208 is programmed to anneal the device for the determined period of time at the corresponding annealing temperature or range of temperatures. In some embodiments, the period of time is 60-70 seconds. In some embodiments, the period of time is as short as 5-10 seconds, while in other embodiments the period of time is as long as tens of minutes. The period of time may be based on empirical data for the particular device(s), package, etc.
It should be appreciated that in some embodiments, the annealing temperature and duration of the annealing process is determined empirically for each new semiconductor device, package, or system design. For example, a prototype semiconductor device is first benchmarked by measuring operational characteristics such as the number of program/erase operations that can be performed within a certain time period, or how long it takes to program/erase a memory cell. Then the device is operated for an extended period of time until defects occur. Again, defects are measured against the benchmarked operational characteristics. The device is then annealed at a particular temperature and for a particular duration. The operational characteristics are again measured for improvement. The process may then be repeated for different annealing temperatures and/or durations using the same or similar devices to determine the optimum annealing temperature and duration for that particular device design. The same process may be used to determine the optimum annealing temperature and duration for semiconductor packages or systems.
The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.
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A memory module includes multiple memory devices mounted to a substrate and one or more discrete heating elements disposed in thermal contact with the memory devices. Each of the memory devices includes charge-storing memory cells subject to operation-induced defects that degrade ability of the memory cells to store data. The discrete heating elements, or single discrete heating element, heats the memory devices to a temperature that anneals the defects.
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BACKGROUND OF THE ART
[0001] 1. Filed of the Invention
[0002] This invention relates to an apparatus for determining the dryness of inked paper using laser light absorption technique for application in inkjet printers. The invention provides direct in-line feedback as to the effectiveness of the drying of the ink placed deposited upon paper or other media. This disclosure describes the associated laser system designs and the technologies employed in the determination of drying efficiency of inks and other liquids placed upon a media.
[0003] 2. Background of the Art
[0004] High speed production inkjet printers print at speeds exceeding 300 pages per minute are cost efficient color printers for many high volume printing applications. Water based inks employed provide lower cost and are more environmentally friendly than other inks. However, the water-based ink may not dry fast enough before the paper is folded or printed on the reverse side, causing print or image quality. The drying of water based inks currently use near infrared (NIR) heating elements, comprised of heating lamps, which can dry water/glycol based inks by heating to vaporize the water and glycol components of the ink formulation. The drying of water-based inkjet ink applied to media by high speed continuous forms inkjet printers is an evolving post-processing product for the printing market. Currently no known method is employed to determine the efficiency of the drying system in real time within the inkjet printer. A method by which real time feedback of the performance of the printer drying system to the controller would be beneficial to the desired dryness of the inked media.
[0005] High speed production inkjet printers manufactured by Ricoh, Canon, Kodak, Xerox and others, use aqueous based inks in many of their products. Water is the largest component, by weight comprising as much as 60%. Other liquid components include glycol and other semi-volatiles. These liquid components spread out onto, and are absorbed into, the print media. The spreading function and absorption into the media is dependent upon the media composition. For example, plain uncoated paper, is absorbs the liquid more readily than a coated paper. Oko, Asaf, et.al (2010) “Imbibition of picoliter water droplets on coated inkjet papers”, NIP26 and Digital Fabrication 2010 Technical Proceedings, pp 475-478. describe the wetting of ink on plain and coated papers with spreading observed over 1 ms of time. K. Vikman, et.al. (2005) “Water Fastness of Ink Jet Prints on Modified Conventional Coatings, IS&T Volume 20, NO.2, April 2005, describe the analysis of various coated papers absorption of ink utilizing FTIR and Raman Spectrometry methods. T. Hartus, (1999), “Thermal Analysis of Ink-Substrate Interactions and Drying in Ink Jet Printing” Graphic Arts in Finland, 28 (1999)1, 3-10 describes TGA and DSC methods to evaluate papers with differing pulp content and the resultant absorption of inks into the papers and the evaporation energies of various inks. Eichhorn et.al, (2013), “Determination of Dryness of Water-based Inket Ink”, NIP29 Digital Printing Conference, September 2013, (proceedings yet to be published at time of patent application), describe FTIR and TGA analysis of wet and dried inked paper as a function of dryness determination after the inked paper had been exposed to a drying system.
[0006] Evaporation of the water and glycol at room temperature is too slow for high speed print applications, where the paper is either stacked or rolled up immediately after printing. Therefore drying of the paper within seconds of depositing the ink to the printed page is advantageous. For water based inks, current drying methods use Near Infrared (NIR) lamps that are positioned along the direction of movement of the printable substrate after the inkjet printing heads, to rapidly heat up the ink and media substrate to vaporize the water and glycol. The NIR lamps have light emission spectra at wavelengths from about 800 to 1100 nm (by way of non-limiting examples). One NIR system is manufactured by Adphos USA (Brookfield, Wis.) that employs multiple NIR heating units consisting of NIR lamps with “focusing” shields above and below the paper in the printer. While massive heat can be generated by NIR lamps, the absorption efficiency into water is very low in the NIR region and much heat is needed to effectively dry the ink sufficiently to avoid smearing or blocking (adherence between sheets caused by binding through the inks). The determination of the dryness of the heated surface is important to the efficiency of the drying system and assurance that smearing and blocking do not occur. An in-line immediate feedback system determining the moisture content within the inked media would be a beneficial component of the printer drying system, which this invention addresses.
[0007] High speed production inkjet printing is an expanding market technology. The drying of water-based inkjet ink applied to media by high speed continuous forms inkjet printers, is an evolving post-processing product for the printing market. The efficiency of the dryers to remove the water and glycols, and other semi-volatile components of the ink can be determined by laboratory analytical techniques. Analytical methods employed to determine the level of dryness of inkjet printed paper utilizing Thermal Gravimetric Analysis (TGA), Fourier Transform Infrared Spectrometry (FTIR) may yield baseline characterizations by which the invention described within is characterized against. Experimental testing FTIR and TGA methods are described here within, showing the ability to discern the level of dryness of a water-based inkjet printed paper sample. The methods provide effective tools for analysis of drying, and point to methods by which real time in-line printer feedback may be developed and characterized as those employed in the invention.
SUMMARY OF THE INVENTION
[0008] The efficiency and positional degree of performance of the dryers to remove water and glycols, and other semi-volatile components of the ink can be determined by optical analytical techniques. Spectral analysis using UV-VIS-NIR and FTIR are well understood analytic tools for chemical identification and material characterization. These techniques have been determined in the present invention to be applicable to the determination of dryness of inked paper by observing the optical absorption level of water within the paper. Light transmitted through paper or reflected from the surface of paper, provides information on the amount of moisture within by the amount of absorption of the light. Water absorbs light efficiently in the UV and the IR spectral regions and can be determined by optical means. FIG. 1 is an absorption spectrum of water showing those peak regions of absorption. The region at about 2900 nm wavelength, the absorption peak is of interest because that is the spectral region where a laser diode optical system may be applied for real time, in-line, analysis of water content, providing immediate feedback to the drying system controller.
[0009] The invention includes a system for determining dryness of an inked absorbent substrate, the system comprising: a laser diode emitting at a predetermined wavelength, an electromagnetic sensor responsive to the predetermined wavelength, the electromagnetic sensor being in information communication with a processor, the processor configured to receive data originated in the sensor to identify moisture content in ink applied to the absorbent substrate.
[0010] An example of a method for practicing technology within the generic scope of the present technology includes a method of sensing dryness of a printed absorbent surface comprising printing the absorbent surface with an ink comprising water or a semivolatile ink, drying the ink, after drying the ink, exposing inked and dried surface of the absorbent substrate to electromagnetic radiation having a wavelength between 1000 nm and 4000 nm, a sensor capturing electromagnetic radiation transmitted through or reflected from the inked and dried absorbent surface, the sensor transmitting data responsive to captured electromagnetic radiation to a processor, the processor receiving the transmitted data and executing code to determine remaining water or semivolatile content in ink at inked, dried and exposed areas.
BRIEF DESCRIPTION OF THE FIGURES
[0011] FIG. 1 is a Water Absorption Spectrum
[0012] FIG. 2 is an Absorption Spectrum, 900-2000 nm, of black and magenta water based ink
[0013] FIG. 3 is an FTIR spectral analysis of water placed on paper and paper dried
[0014] FIG. 4 is an FTIR spectral analysis of ink placed on paper and paper dried
[0015] FIG. 5 is a TGA of dried paper sample
[0016] FIG. 6 is a TGA of Magenta ink
[0017] FIG. 7 is a Table of ink water and glycol percentage contents
[0018] FIG. 8 a is a Laser optical system of invention
[0019] FIG. 8 b is a Laser optical system of invention utilizing multiple wavelengths of light
DETAILED DESCRIPTION OF THE INVENTION
[0020] The efficiency of dryers to remove water and glycols, and any semi-volatile components of the ink can be determined by optical analytical techniques. Spectral analysis using UV-VIS-NIR and FTIR are well understood analytic tools for chemical identification and material characterization. These techniques can be applied to the determination of dryness of inked paper by observing the optical absorption level of water within the paper. Light transmitted through paper or reflected from the surface of paper, provides information on the amount of moisture within by the amount of absorption of the light. Water absorbs light efficiently in the UV and the IR spectral regions and can be determined by optical means. FIG. 1 is an absorption spectrum of water showing those peak regions of absorption. At 2900 nm wavelength, the absorption peak is interest because that is the spectral region where a laser diode optical system may be applied for real time, in-line, analysis of water content, providing immediate feedback to the drying system controller.
[0021] The invention includes a system for determining dryness of an inked absorbent substrate, the system comprising: a laser diode emitting at a predetermined wavelength, an electromagnetic sensor responsive to the predetermined wavelength, the electromagnetic sensor being in information communication with a processor, the processor configured to receive data originated in the sensor to identify moisture content in ink applied to the absorbent substrate.
[0022] The system may have the laser diode emit at a wavelength between 1000 and 3000 nm, such as at a wavelength within ±20 nm of 1450 nm, 1550 nm, and 1950 nm along with 2900 nm. The processor may have a stored lookup table that is used by execution of code by the processor to compare the data received with the lookup table to determine dryness of ink with respect to water and/or semivolatile liquid within the previously applied to the absorbent surface.
[0023] The sensors may receive reflected electromagnetic radiation or transmitted electromagnetic radiation to originate the data from the sensor.
[0024] The processor may have a stored lookup table that is used by execution of code by the processor to compare the data received with the lookup table to determine dryness with respect to organic semivolatile carrier content of ink previously applied to the absorbent surface. The organic semivolatile may contain a glycol.
[0025] A method for practicing the present technology may include a method of sensing dryness of a printed absorbent surface comprising printing the absorbent surface with an ink comprising water or a semivolatile ink, drying the ink, after drying the ink, exposing inked and dried surface of the absorbent substrate to electromagnetic radiation having a wavelength between 1000 nm and 4000 nm, a sensor capturing electromagnetic radiation transmitted through or reflected from the inked and dried absorbent surface, the sensor transmitting data responsive to captured electromagnetic radiation to a processor, the processor receiving the transmitted data and executing code to determine remaining water or semivolatile content in ink at inked, dried and exposed areas.
[0026] The method may use electromagnetic radiation having a wavelength between 1000 nm and 4000 nm is emitted from a laser diode, such as wherein the laser diode emits at a wavelength within ±20 nm of 1450 nm, 1550 nm, and 1950 nm along with 2900 nm. The method may have the processor execute code to compare received data to a lookup table stored in memory of the processor to determine remaining water or semivolatile content in ink at inked, dried and exposed areas. The method may have the processor execute code to compare received data to a lookup table stored in memory of the processor to determine remaining water content in ink at inked, dried and exposed areas.
Experimental Background
[0027] FTIR, TGA and GCMS analytical techniques here have been applied to the determination of dryness of water-based inkjet ink on paper. Samples of paper with water-based ink were tested after printing and after drying. Paper without print was tested as a control for each test. Water and glycol are the major semi-volitile components within ink formulations and are foremost in the consideration of dryness of inked paper after drying. Water has strong spectral absorption peaks in the UV and in the IR wavelengths. FTIR Spectrometry shows clearly the water absorption peak in the IR at about 2900 nm wavelength and therefore is one of the methods herein chosen in the determination of dryness according to the present invention. TGA records the weight loss as the material is heated. TGA can determine the percent of water and other ink components that are driven off the material under test as heat is applied. GC-MS used with micro-extraction head space testing can determine the amount of volitiles evolved as the inked paper is heated. Each of these analytical methods are applied to paper, paper with water-based ink applied, and to inked paper that has been dried.
[0028] First order analysis of dryness can simply be seen by comparison of before and after drying of the paper with FTIR and TGA. Since water is the major component to be dried from the paper, an initial analysis was conducted by spreading 10 micro liters of water onto a 9 mm wide by 70 mm long (16 nano liters/mm 2 H 2 O) piece of commercial inkjet paper that has a surface coating suitable for inkjet printing. FIGS. 3 and 4 are data showing blank paper, water on paper, and dried paper. The paper was placed into the FTIR ATR fixturing. The FTIR spectra, FIG. 3 shows water's absorption peak is at 2900 nm, or 3500 wave numbers and indicates that the blank paper contained some moisture as seen with a slight dip in the percent transmission. The water content after applying 10 micro liters of water, is clearly seen by the dip of percent transmission to 97.5%. The removal of the water after drying at 100° C. for 20 minutes, is seen by the “convex” percent transmison at 2900 nm. The TGA data, FIG. 4 , of the same blank paper and watered paper, shows the percentage weight (% wt) loss of the water component as the paper is heated through 250° C.
[0029] Micro-extraction head space analysis using GC-MS is applied to the determination of dryness to determine the amount of volatiles that are vaporized from the heating of an inked piece of paper. In this technique, a small piece of measured dimensions and weight are placed into a small head space chamber (glass vile) and heated to 200° C. The vapors that are driven from the paper are absorbed on a micro fiber over a period of time. The micro fiber absorbs the semi-volitiles such as glycols. The fiber is then desorbed into the GC-MS. Analysis of the resultant specta identifies the chemicals which have been collected and the amount of the material. This technique, though not applicable to water vapor, will enable the qualitative and quantificative analysis of the volotile chemical emitted, and is relateable back to the TGA and FTIR data.
[0030] Ink testing was first analyzed by the present technology using TGA to determine the temperatures at which the comprising components are evaporated. Each color of ink has different volume, by percent mass, of water and glycol components and can be determined by TGA. Each of the inks were heated through 800° C. to determine the evaporation temperatures and percentage by weight of all the ink components, including pigments. In addition, mixtures of known ink components were mixed in different ratios and TGA performed on those mixtures to help further characterize the data on each ink. These two TGA tests were conducted to provide baseline information on the inks to be studied. In addition, Infrared spectrometry, FTIR, was performed on each of the inks to help further identify components of the inks. Furthermore, UV-VIS spectral analysis and Differential Scanning Calorimetry (DSC) were used to further identify optical and thermal properties, including heat flow, of the inks. This is not relevent to the drying analysis of the ink, but provides additional information to better understand the inks to be used in optimizing the practices of the present invention.
[0031] Commercially available ink used in a very high speed production inkjet printer was analyzed by TGA, FTIR and GC-MS. As described in the proceeding section, each of the color inks were analyzed for the percent of water and glycol components. Each ink was then applied to a coated inkjet paper, 9 mm×70 mm dimensions, in the amount of 10 microliters across the surface. The inked papers were analyzed before and after drying for the change in moisture content of a known amount of ink deposited upon a measured area.
[0032] FIG. 6 is a TGA analysis of the magenta ink, showing the relative percent by weight of the water and glycol components. FIG. 7 (Table 1) is a summary of the primary color inks and the weight ratios of water and glycol obtained by TGA. Knowing the starting ratio, will help determine the relationship to dryness to be determined in this study.
[0033] The first ink analyzed was the black ink. As given in FIG. 7 (Table 1), the water content was found to be 74% and the glycol 8% by wt. After applying 10 microliters of the ink to the 630 mm 2 strip of paper (16 nl/mm 2 ), the strip was then placed into the FTIR-ATR fixturing and tested. A 25 mm 2 piece of the paper was then tested with the TGA to a temperature of 250° C. The inked paper was then dried at 100° C. for 20 minutes and re-tested in the FTIR and TGA. FIG. 5 is the resultant FTIR spectraa and FIG. 6 is the TGA plot. Each clearly show the significant reduction in water after drying of the inked paper.
[0034] The labatory techniques described serve as a basis by which to characterize and quantify the efficiency of laser optical systems according to various embodiments of the invention. The choice of specific lasers that emit light at the absorption peaks of water, provide a simplified, concentrated system as compared to that of an FTIR optical arrangement. The invention employs laser diodes specific to the spectral absorption peaks of water, in an optical system that interrogates transmitted and/or reflected light from an inked media for the percentage of light absorption at the spectral absorption peaks of water. As with the examples of FTIR analysis described in this section, the laser optical system of the invention provide a method by which the level of dryness can be determined. The invention will provide immediate feedback to the dryer controller through micro processor control of the intensity readings of the laser optical system.
[0035] FIG. 1 the Absorption Spectrum for water. Water has major absorption peaks in the ultravilot region of the spectrum and then again in the infrared region with largest absorption after or about 2900 nm or 3500 wave number. The region from 400 to 1000 nm electromagnetic radiation is transmitted through water and not until 1100 nm does it begin to be absorbed more effeciently. Peaks in the 1450, 1550 and 1950 nm regions provide sufficient absorption energy to be considered for laser drying determination. The 2900 nm peak is of special interest because of the maximum absorption efficiency available and diode lasers of sufficient power are available that emit at that wavelength to be applied to determination of dryness.
[0036] FIG. 2 is the Absorption Spectrum, at 900-2000 nm, of black and magenta water based ink. The two absorption peaks observed for these two inks at 1450 and 1950 are of interest to apply laser diodes with light emission at those wavelength for drying analysis.
[0037] FIG. 3 is an FTIR spectral analysis of water placed on paper and the paper dried. Ten micro liters of water was applied to a 9×70 mm piece of coated inkjet paper. The paper spectra were determined by FTIR with the reflective ATR attachment. The resultant reflective spectra clearly show the water absorption peak at 3500 wave numbers, 2900 nm. The paper was then dried at 100° C. This figure clearly shows the ability to discern the dryness of the paper by observing the absorption spectra of water at 2900 nm.
[0038] FIG. 4 is an FTIR spectral analysis of ink placed on paper and paper dried. The same experiment was applied as described for FIG. 3 . Again, the resultant spectrum of the dried paper compared to the inked paper shows that observing the absorption spectra of water at 2900 nm is an effective step in a method to determine dryness.
[0039] FIG. 5 is a TGA plot of the paper sample described in FIG. 3 . A small piece of the sample, 5 mm diameter, of the same watered paper of FIG. 3 , was analyzed before and after drying. The TGA further verifies the efficiency of drying and is an analytical method to help quantify the percentage of moisture content and resultant drying as seen with the FTIR analysis.
[0040] FIG. 6 is a TGA plot of Magenta ink, as an example, determining the ratio of water and glycol components of the ink.
[0041] FIG. 7 is a Table of ink water and glycol percentage contents and is of reference in determining the amount of water and glycol contained within an inked sample being dried.
[0042] FIG. 8 a depicts a sample laser diode optical system of invention. The diode laser is chosen from IR lasers whose center wavelengths are in the peak regions of water absorption, for example 2900 nm. The laser light is used to sample a region of the inked paper by either transmission or reflection or transmission and reflected light and record the absorption percentage of the light. The optical system may utilize lenses and or fiber optics to shape and focus the beam as well as collect the light and guide it to a photo detection system to analyze the absorption efficiency.
[0043] FIG. 8 b is a Laser optical system of the invention depicting multiple wavelengths of light with emissions at 1450, 1950 and 2900 nm within the optical system that is depicted in FIG. 8 a.
[0044] FTIR spectral analysis is an effective tool to determine the presence of water on a surface, within a surface or within a substance. FTIR-Transmission and FTIR-ATR reflectance studies have shown that water absorption at 2900 nm wavelength can be interpeted as to the amount of water that is contained within the material tested. Correlation studies using TGA can confirm and correlate the percentage of water content within the media. thus showing that optical analysis is a viable method of water content determination. Laser diode optical systems are used in LIDAR systems which detect moisture in the field of view in the atmosphere. A similar arrangement may be applied to determination of moisture content within a printed media such as paper that has had ink deposited on it. A transmission or a reflectance laser optical system can be designed to observe the water content within an ink printed media, such as paper, by measuring the level of absorption of incedent laser light. Choosing the wavelength of light to have maximum intensity at one or more major absorption peaks of water allows the absorption ratio to be easily observed. Laser diodes emitting in the IR spectrum, specifically in the 1450, 1550, 1950 and 2900 nm regions, are where the greatest absorption of light by water occurs. A laser diode optical system emitting one or more of those wavelengths would provide the ability to rapidly determine the water content of the inked paper and therefore the amount of dryness of the inked paper. The transmissive and/or the reflective laser light is collected with optics that deliver the analytical photons to a photodetection system. The photodection system consists of photodiodes whose resultant output waveforms show the variations in light intensities due to the amount of light absorption of moisture, water & glycols, contained withing the sample region being observed by the optical system. A photodetection system may utilize a single laser diode emitting in the 2900 nm region, the largest absorption peak of water. The photodetection system may also utilize multiple wavelengths emissions at additonal water absorption peak regions of 1450 nm, 1550 nm, and 1950 nm along with 2900 nm, and the comparison of the absorption percentage of each. The analysis of the intensity of the collected photons by the photodiodes can be quickly determined by a microprocessing system (by configuration of the processing system to execute software) designed to interpert the resultant intensities as to the amount of moisture content contained within the sampling area. By use of look up tables and other software incorporated within the processing component of the invention, instructions are relayed back to the processor control unit of the drying system of the inkjet printer.
[0045] The optical system and method described within this disclosure may use one or more of the laser diodes emitting in the water absorption peak regions of 1450, 1950 and 2900 nano meters wavelengths. The laser diode system embodied in the invention is composed of laser diodes, optical system delivering laser light to the region to be interigated, optical system delivering transmitted or reflected light from the interigated region to a photodiode system and a micro controller system to record and interpert the light intensities of the interigated region as to the percentage of moisture contained within the interigated region. The resultant determination is feed back to the microprocessor controller of the drying system of the printer for adjustments of heating to achieve the desired level of dryness of the inked media. For example, where the drying of the ink was performed with laser radiation and after determining a level of remaining water or semivolatile content in ink at inked, dried and exposed areas, the processor or an operator may alter characteristics of the laser radiation used to dry the ink by at least one parameter selected from the group consisting of laser intensity, laser duration, laser spot size and laser spot overlap. The duration can be enabled by adjusting the speed of the substrate pass-through, but this is less preferred as the efficiency of the process may be altered adversely.
[0046] Although specific components, wavelengths, times and temperatures are reported, these are specific examples within the generic scope of the present technology and are not to be read as limiting the generic scope of the invention. The present technology may also be used in the coating of adhesives to surfaces (especially water-based adhesives), decorative coatings to surfaces, and the application of active ingredients to surfaces in high speed printing processes.
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An apparatus determines the dryness of inked paper using laser light absorption technique for application in inkjet printers. Direct in-line feedback is provided as to the effectiveness of the drying of the ink placed deposited upon paper or other media. Associated laser system designs and the technologies employed in the determination of drying efficiency of inks and other liquids placed upon a media are enabled.
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RELATED APPLICATION
This application is a continuation-in-part of my co-pending application, Ser. No. 069,895, filed July 6, 1987 and now U.S. Pat. No. 4,779,902.
BACKGROUND OF THE INVENTION
With the advent of plastic pipe such as polyolefin and other plastic materials, there has existed a need for connecting lengths of pipe together to form a string of pipes. The use of such plastic pipe has ranged from an inch or so in diameter to as much as five feet.
The connecting together of such pipes has presented a problem which is of particular significance in the field where access to equipment and labor may be difficult. While fusion of the pipe ends has been done for some time, this has generally been somewhat laborious and expensive.
Various types of end connections have been devised requiring clamps and auxiliary paraphernalia. One such device using clamping is shown in the exterior pipe connector sleeve of U.S. Pat. No. 4,310,184 in which the pipe ends are butted together and clamped by the sleeve. This device and other end clamps require extraneous parts with the danger of the protruding clamp being accidentally struck and damaged by external forces. For example, when joined strings of pipe are pulled in a slip-lining construction job, it is particularly desirable that the exterior of the pipe be completely flush to enhance the pulling or pushing of the pipe along the ground or through a large pipe to be repaired.
Further problems have been a tendency for connected ends to pull apart while in service with consequent damage to the pipe line and environment and difficulty in location of the break and repair.
SUMMARY OF THE INVENTION
By means of the instant invention there has been provided a plastic pipe having an integral end connection which may be joined with a like plastic pipe or a semi-rigid pipe having a mating integral end connection. The adjacent pipes may be pushed together to mate the end connectors in a locking engagement to resist any tendency to separate the joined pipe ends.
The plastic pipe employed is desirably of a polyolefin nature such as polyethylene, polypropylene or polybutylene having semi-rigid characteristics but also having the ability to flex or bend and expand and compress to a slight degree to accommodate the interfit of the male and female end connections of the pipe when press-fitted together. It will be understood that other plastic pipes having similar characteristics may also be used. The integral end connections may be formed in the pipe when fabricated in the molding process or later such as by machining or the like.
The structure of the end connection is in the nature of one or more axially extending wedge shaped internal ribs and grooves formed on the interior of the female member which interfit in locking relation with one or more wedge shaped exterior ribs and grooves formed on the exterior of the male member. When the male member is forceably pushed into the female member the latter is slightly expanded or distended while the male end may be slightly compressed until the two members are mated together at which time the female member contracts to its normal state and the male member expands to its normal state to lock the two members together and, through a wedge shaped interfit of the ribs and grooves, resist separation forces.
The wedge shaped ribs and grooves may be in the form of slanted or indented sides of the ribs and grooves which underlie one another in an axially extending direction and resist any tendency to pull apart when the ends are connected together. The wedge shaped configuration may be on the sides of the ribs and grooves which are engaged in the press-fit operation as well as the opposite sides to provide the locking engagement. The wedge shaped configuration may be conveniently provided by a dove-tailed trapezoidal shape or in the form of a mating bead and groove interfit for the ribs and the grooves.
When a dove-tailed trapezoidal shape or the like is employed where a pointed edge of a rib engages a groove corner in the pressfitting engagement, or where substantial forces of compression or tension are otherwise encountered, the corners of the ribs and grooves may be substantially rounded. This provides for stress distribution and spreading of the force and pressure to minimize any tendency to break or tear a rib in the pressfitting operation or forces encountered in service which might tend to separate the pipe.
The end ribs of both male and female members are slightly bevelled or chamfered to facilitate the sliding of the male member. To further ease this movement where a series of ribs are employed, the end or outer ribs of both the male and female members are wider than the corresponding end or outer grooves to prevent premature locking of the ribs and grooves before the members are fully engaged. This relationship enables the end of the male member to ride past the end of the female member until it approaches a shoulder stop of the female member to provide proper registration of the ribs and grooves for the final locking engagement.
The above features are objects of this invention. Further objects will appear in the detailed description which follows and will be otherwise apparent to those skilled in the art.
For purpose of illustration of this invention a preferred embodiment and modifications thereof are shown and described hereinbelow in the accompanying drawing. It is to be understood that this is for the purpose of example only and that the invention is not limited thereto.
IN THE DRAWINGS
FIG. 1 is a view in axial section of the pipe having the integral end lock connections before being joined;
FIG. 2 is an enlarged view in axial section showing the joined ends of the pipe;
FIG. 3 is a further enlarged fragmentary view in axial section similar to FIG. 2 showing the interlocking connection and having an additional rib and groove series;
FIG. 4 is an enlarged view in axial section showing the rib engagement with a rounded groove corner;
FIG. 5 is a view similar to FIG. 4 showing a modified rib and groove corner construction;
FIG. 6 is an enlarged exploded view in axial section showing a superimposed connection with a further modified rib and groove construction; and
FIG. 7 is a schematic view on a reduced scale showing a clamp and ram for forcing ends of the pipe together.
DESCRIPTION OF THE INVENTION
The plastic pipe having the integral end connections is generally illustrated by the reference numeral 10 in FIGS. 1-3 and 7. Each length of pipe is provided with a female connection 12 and a male connection 14, although it will be understood that where desired alternate pipes may have both ends with male and female connections and that the pipes may be fitted together in this fashion.
The plastic pipe is preferably polyethylene but other polyolefin pipes, such as polypropylene and polybutylene, having similar characteristics of being semi-rigid, the ability to bend slightly along substantial lengths and having the capacity to distend or contract slightly may be employed. The pipes may range in diameter from about three inches to over five feet and have a substantial wall thickness to withstand internal and external pressures and resistance to abrasion when the pipes are moved along the ground in various types of construction.
The integral female and male end connectors are formed on the interior and exterior surface in the fabrication of the pipe itself as in the molding process or by machining. Each of the end connections has one or more ribs and grooves which interfit with one another when the female and male end connections are press-fitted together as will be more fully described hereinbelow. When fitted and locked together the joined pipes present a flush continuous internal and external surface which reduces internal friction or resistance to fluid flow on the interior and provides a smooth external surface presenting no impediment or drag when moved along the ground or through a pipe as in a slip-lining operation.
The female end connector 12 is comprised of an end or outer dove-tailed axially extending wedge shaped rib 16 and an inner similar wedge shaped rib 18. A first or outer wedge shaped groove 20 separates the two ribs while a second or interior wedge shaped groove 22 separates the inner rib 18 from a stop shoulder 24 as best shown in FIG. 2. The sides of the wedge shaped grooves slant from the perpendicular with the angle of the slant being, for example, 8° but it will be understood that the degree of the slant may be varied as desired. FIG. 3 shows a groove 25 separating a second inner rib 27 from the stop shoulder 24. In order to facilitate the joining or riding together of the female and male end connections, the end rib 16 has a bevelled or chamfered surface 26 formed at the outer corner of the rib.
The male end connection 14 has ribs and grooves formed in a similar fashion to that of the female end connection 12 but on the exterior of the pipe. Thus, the male end has an end or outer wedge shaped rib 28 formed on the pipe along with a second or inner wedge shaped rib 30. A first or outer wedge shaped groove 32 separates the two ribs while a second or inner wedge shaped groove 33 separates the inner rib 30 from a stop shoulder 34. FIG. 3 shows a groove 35 separating a second inner rib 37 from the stop shoulder 34. A bevelled or chamfered surface 36 is formed at the outer corner of the male end connection which facilitates the joining together of the end connections and distends or expands the female end connection and compresses the male connection by the wedging or camming action when the bevelled surfaces 26 and 36 of the female and male end connections are pressed together.
In order to ensure that the ribs and grooves of the female and male end connections do not prematurely engage until the full joined connection is made, as shown in FIG. 2, the end or outer ribs 16 and 28 of the female and male end connections, respectively, are constructed to be wider than the end grooves 20 and 32 of the female and male end connections, respectively. This prevents engagement of the ribs in these grooves. Proper engagement of the aforementioned end ribs 16 and 28 occurs when the female and male end connections are completely pushed together at which time engagement of the aforementioned ribs 16 and 28 occurs in the grooves 33 and 22, respectively, as will be seen in FIG. 2. FIG. 3 shows the engagement of ribs 16 and 28 with grooves 35 and 25, respectively. Similar engagement of the inner ribs 18 and 30 of the female and male end connections, of somewhat lesser width than the end ribs, will take place in the outer grooves 32 and 20 of the male and female end connections, respectively. It will be understood that a slight tolerance is provided for the interfit of the ribs in the mated relation in the grooves as will be well understood in the art.
Where desired the tolerance may be eliminated and the ribs may be made slightly wider at the outside or end than the mouth of the grooves with the registering exterior corners of the ribs or grooves, or both, being chamfered, bevelled or rounded. By this relationship a camming action may be effected to force the slightly wider ribs into the grooves by taking advantage of the slight resiliency of the polyolefin pipe. This relationship also augments the wedging interlock of the ribs in the grooves.
A locking relationship for the ribs and grooves when the male and female end connections are joined is provided for the ribs and the mating grooves through the wedge shaped configuration and the opposed slanting sides of the ribs. As best shown in FIGS. 2 and 3 the wedge shape is in the form of a trapezoid but it will be understood that outer wedge shaped forms may be utilized in order to provide a locking engagement. In the trapezoidal form the slanting sides of the ribs and grooves which bear and mate against one another, as shown in FIGS. 2 and 3, provide resistance to forces such as by compression or tension tending to separate the rib and groove engagement.
In order to reinforce the joined end connections when coupled together, a reinforcing sleeve 38 as shown in FIGS. 1, 2 and 6 may be employed. The sleeve may for great strength be of steel but it will be understood that other materials such as polyethylene or the like may be employed. The sleeve may be employed to improve the strength of the coupled end connections to withstand internal pressures up to the design rating of the remainder of the pipe. As shown in FIGS. 1 and 6, the sleeve may be fitted snugly by a slidable friction fit on the female end of the pipe 12, or on the male end 14 as desired, slightly away from the end connection structure and, after coupling, moved axially to cover the coupled end connections.
A modified axially extending wedge shaped rib and groove construction is shown in FIG. 6 in which the wedge shape portion has a greater width than the remainder of the respective rib and groove to provide what may be termed a modified dove-tail wedge. In this form the wedge shaped ribs are formed by a bead 40 at an exterior corner of the ribs which is adapted to engage a slot or groove 42 at an interior corner of a mating groove within the rib. This relationship when the male and female ends are connected provides a wedging and locking engagement. An additional feature of the bead and groove engagement is provided by the rounded interfit which effectively distributes stress at the interfitting corners to distribute or diffuse force concentration in the region due to press-fitting which might tend to break or tear the ribs. While the bead 40 is shown at a leading exterior corner of a rib of the male member 14 and a trailing interior corner of a groove of the female member where the stress occurs, it will be understood that this relationship may be reversed and that the bead may be on a leading exterior corner of a rib of the female member and that the groove may be at a trailing interior corner of a groove of the male member. Both types of relationships may also be utilized.
The trapezoidal dove-tail shaped ribs and grooves may also be provided with a feature to distribute stress or the interfitting corners of the ribs and grooves when press-fitted together or to withstand compression or tension forces encountered during service. It should be understood that when pressure or tension is placed on the joined male and female end connections the exterior corners of the trapezoidal wedge shaped ribs may exert great force on the interfitting interior corners of the mating grooves. In order to diffuse or distribute the force and prevent a point-like concentration the interior corners of the grooves are provided with a rounded shape 44 as shown in FIGS. 3 and 4. In order to maximize the force distribution the exterior corners of the ribs may likewise be rounded at 46 as shown in FIG. 5.
Where the forces encountered are compression forces such as from the press-fitting of the male and female end connections the rounded interior corners at the trailing interior corners of the grooves and the leading exterior corners of the ribs need only be rounded. Where opposite or separation forces may be encountered, such as by tension in pulling a string of connected pipe lengths along the ground, the trailing exterior corners of the ribs and the leading interior corners of the grooves may be rounded, and it will be understood that one or both the force conditions may be accommodated as desired by rounding all the exterior corners of the ribs and all the interior corners of the grooves.
As an actual example, the female and male end connections may be formed in length of 20 to 40 feet of polyethylene pipe having an outside diameter of 6.63 inches and an internal diameter of 6.19 inches and a modules of elasticity of 100,000 psi to 140,000 psi at room temperature. In the press-fitting together of the female and male end connections an axial force or 900 pounds to 1,100 pounds may be applied. Deformation or distending of the female end connector and compression of the male end to accommodate the interfit of the male member as the respective ribs slide over one another until registering engagement is effected is about 2%, well under an upper limit of about 5%, which can be safely encountered before a permanent distortion.
When the pipe is to be joined together, a gasket compound or sealant such as that shown at 48 and 50 in FIG. 3 may be employed. This may be in the form of any conventional sealant such as a flexible butyl rubber sealant or the like. The sealant may also be used between the ribs and grooves to fill the spaces therein to enhance the wedging and locking action.
USE
The pipe of this invention with the integral end connections is simply and easily connected together to provide a stable and reliable locking engagement. This is of particular advantage in the field where labor and equipment may be difficultly accessible.
One method of joining the separate lengths together comprises a clamp and press device, generally indicated by the reference numeral 52 in FIG. 7 may be employed. One pipe length 54 having a female end connection 12 integrated therein may be clamped by the clamp 56 while another pipe length 58 having a male end connection 14 is clamped in a moveable press clamp 56 powered by a hydraulic piston 62 or the like moveable in the direction of the arrow. The pipe length 58 is moved toward the pipe length 54 to insert the male end connection into the female end connection until the complete locking interfit shown in FIGS. 2 and 3 is obtained. A reverse arrangement of the pipe lengths in the clamped press device may be employed as will be readily understood.
Other means for joining may be employed which, per se, form no part of this invention. In the field, hand winches or come-a-longs, heavy construction equipment such as bulldozers, back hoes and the like may be used to push one length of pipe into another pipe which may be anchored or fixed against movement in one fashion or another.
The pipe lengths may be joined in a string of pipe lengths and pulled or pushed to any desired final location. The locked joint when sealed with the flexible butyl rubber sealant assures a water tight joint preventing both infiltration and exfiltration. This is particularly beneficial where the corrosion, abrasion resistance and the flexibility of polyolefin pipe is needed.
The outside and inside surfaces are flush and of constant diameter which enhances fluid flow and obviates external fittings and protruberances which would cause problems in pulling the pipe along the ground or in the interior of a larger pipe to be repaired as in the case of slip-lining. Further, no reduction in pipe size is required as where external clamps are employed.
When joined, the locking interfit provided by the wedge shaped ribs and interfitting grooves resist any tendency for separation between the joined connections. The rounded corners of the grooves and ribs further provide the effective stress distribution to avoid rib damage or breakage in the press-fitting joining operation or forces encountered in service after the pipe ends have been connected. Where greater strength is required to withstand high internal pressures, the reinforcing sleeve 38 may be simply employed by sliding it axially over the coupling.
While the end connections have been disclosed for both the female and male end connections as being formed integrally in plastic pipe for use with each other, it will be understood that in some cases there may be a connection to a rigid steel pipe or the like, equipped with mating ribs and grooves, as at the terminal or start of a line or the like.
Various changes and modifications may be made within this invention as will be apparent to those skilled in the art. Such changes and modifications are within the scope and teaching of this invention as defined in the claims appended hereto.
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Plastic, such as polyolefin, pipe having a locking integral end connection. The pipe is fabricated with male and female end connections in order that the pipe may be press-fitted together with the interior and exterior forming a flush uninterrupted surface. One or more radial ribs and grooves are formed on the interior of the female connection while a registering series of ribs and grooves are formed on the exterior of the male connection. The ribs and grooves are of an interfitting axially extending wedge shaped configuration to provide a locking engagement to resist any tendency for separation. Interfitting corners of the ribs and grooves may be rounded to distribute stress and minimize damage when the pipe ends are fitted together. The ends of the pipe are bevelled in order that the ends pressed together engage and by the slight resiliency of the polyolefin pipe construction permit the slight expansion and contraction of the ends to provide a locking interfit of the respective ribs and grooves in the two ends. A reinforcing sleeve may be used over the coupling for additional strength. The wall thicknesses of the end connection and width of the ribs and grooves are particularly dimensioned in order that the male end may be inserted to a complete lock position without premature engagement.
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CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation of application Ser. No. 09/986,203 filed Nov. 7, 2001.
This application claims the priority of German Application No. 100 55 026.6 filed Nov. 7, 2000, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
This invention relates to a system and a method for controlling a group of fiber processing machines, such as carding machines and/or draw frames. The system has at least one superordinated control console, and each machine has a machine-specific control console. All control consoles are connected with one another by control and regulating devices (computers) via a network.
In practice, up-to-date textile machines have high- performance controls, by means of which a plurality of functions may be performed and controlled. This applies particularly to the machine control by operating personnel. Such a control has become increasingly more complex and more difficult to overview and to manipulate because of the increasing number of choices as concerns input and setting. Also, more and more information, data and details are available which have to be prepared and made visible for the operating or maintenance personnel. To meet these requirements, complex and expensive control consoles or visual indicating devices are being used. Such devices are computers with monitor screens, keyboards and/or touch screens. It is a significant disadvantage of such an arrangement that the equipment is, as a rule, very expensive. The expenses are often several times the cost of conventional equipment and such a cost applies to each and every machine. Particularly high costs are encountered in case a large number of machines are used which may be desirable from a technological or manufacturing point of view. In addition, the numerous functions of these devices are, as a rule, utilized only relatively rarely, that is, only in certain situations.
International patent document WO 92/13121, to which corresponds U.S. Pat. No. 5,517,404, describes a process control system which has a master computer and a network having a computer of a machine control arrangement of, for example, a pre-yarn transport system. Each computer has a dedicated memory and drive. The drivers determine the necessary interfaces for the communication of the computers with their user interfaces, designated as display devices, controls and printers. The system is programmed and configured in such a manner that the master computer may perform machine control support via the user interface of the respective machine; that is, the master computer may send control commands over the network and the machine controls may receive and obey such control commands so that the condition of the user interface is determined by the master computer via the respective control. Such a system is very complex and expensive. It is a particular drawback that the operation of the machines is controlled from the master computer. The disadvantage resides in the manipulation of complex control consoles for merely a few desired inputs for the manufacturing operation of the respective individual machines, such as on and off switching, coiler can replacement, and indicator displays.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved system and method of the above-outlined type, from which the discussed disadvantages are eliminated and which is structurally significantly simpler and further ensures a simplified machine control and display for the personnel.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the control system for a group of fiber processing machines includes a superordinated control console; and separate machine-specific control consoles connected to each respective fiber processing machine. The superordinated control console and the machine-specific control consoles are connected to one another by control and regulating devices via a network. The superordinated control console includes a stationary unit having arrangements for supplying current, for communicating with said network, for storing and administering data, and a computer. The superordinated control console further includes a mobile unit having an operating and displaying unit.
The measures according to the invention provide for a significant system-wise simplification as well as a simplified machine control and display. Particularly from the technological point of view it is feasible to perform certain setting and parametering steps directly at the machine, combined with complex numeric or graphical indications which go beyond the purely production-specific machine handling. For an effective and economical realization the central control console is a two-part construction. The first part is stationary and essentially contains a current supply, a system for communicating with the network, a data storage and administrating system as well as a computer. On the other hand, the control and indicating part is constructed such that it is separate from the stationary part and may be used as a mobile terminal. Thus, all the machines are adapted, on the one hand, to mechanically receive the mobile control and indicating part of the central control console at a suitable location and, on the other hand, to couple the mobile part electrically with the machine computer which is also connected to the stationary part of the central control console via the available network. No significant handling difficulties appear by virtue of the possibility of performing, when needed, all machine settings, parameter settings and inquiries with corresponding graphical support which are directly required at the machine. This is particularly so, because, as a rule, these tasks are performed as deliberate steps, and occur relatively seldom in normal operation. Also, it is almost impossible that they are performed simultaneously at several machines. It is a further advantage that because of the reduced number of more complex structural groups, the risk of outage as well as the required spare part acquisition are significantly diminished. Overall, the system according to the invention makes possible a practical and cost-effective solution without the need of taking into account substantial technical or technological limitations. Also, it is almost impossible that they are performed simultaneously at several machines. It is a further advantage that because of the reduced number of more complex structural groups, the risk of outage as well as the required spare part acquisition are significantly diminished. Overall, the system according to the invention makes possible a practical and cost-effective solution without the need of taking into account substantial technical or technological limitations.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective view of a system composed of eight carding machines and three draw frames which are connected by a data network with a central handling and displaying apparatus (central control console).
FIG. 2 is a schematic view of a system formed of four carding machines each having a machine-specific control console which are connected with the central control console by a data network.
FIG. 3 is a diagram showing the several control and display functions assigned to the control consoles.
FIG. 4 is a diagram showing the central control console, having a stationary and a mobile part.
FIG. 5 a is a diagram illustrating the several control and display functions assigned to the control consoles, and a mobile terminal coupled to the stationary part of the superordinated control console.
FIG. 5 b is a diagram illustrating the several control and display functions assigned to the control consoles, and a mobile terminal coupled to a machine control apparatus.
FIG. 6 is a diagram illustrating the connection of a modem to the central control console and the connection with a mobile telephone equipment via a wireless station.
FIG. 7 is a schematic side elevational view of a carding machine with a block diagram for controlling and regulating the carding machine.
FIG. 8 is a schematic side elevational view of a draw frame with block diagram for controlling and regulating the draw frame.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a spinning preparation system composed of eight carding machines 1 a - 1 h and three draw frames 2 a , 2 b and 2 c . The carding machines 1 a - 1 h are connected by a data network 3 to a superordinated control console 4 which comprises, among others, a monitor screen 5 and a keyboard 6 and may further include a printer 7 . The carding machines may be high-production DK 903 models, the draw frames may be high-production HSR 1000 models and the data network may be a TEXNET model, all manufactured by Trutzschler GmbH & Co. KG, Monchengladbach, Germany.
As shown in FIG. 2, four carding machines 1 a - 1 d are each connected with a respective, machine-specific control console 8 a - 8 d , each having a respective keyboard 9 a - 9 d and a monitor screen 10 a - 10 d . Each control console 8 a - 8 d is connected with a respective electronic machine control and regulating device 11 a - 11 d , for example, a microcomputer.
As illustrated in FIGS. 1 and 2, all the carding machines and draw frames of the system are connected with a communication network 3 and can exchange data with one another or with other devices. The central control console 4 has a monitor screen 5 , a touch screen, a keyboard 6 as well as capabilities to store data in large quantities over a long period of time. Based on this arrangement, it is feasible to centrally perform all complex machine-setting, parameter-setting and inputting steps. In addition, numerous data of the individual machines may be displayed, visualized, stored, exchanged and monitored.
Each machine (such as the cards 1 a - 1 d according to FIG. 2) has a relatively simple and inexpensive respective terminal 9 a - 9 d , by means of which only those inputting steps are performed which are necessary for the normal manufacturing operation. Likewise, the displays 10 a - 10 d belonging to the respective terminals 9 a - 9 d cover only such a working field. According to FIG. 3, a clear division is effected between a first group composed of control and display pertaining to the normal manufacturing operation and a second group required for the machine-setting, parameter-setting, and visualizing steps as well as error detection. The first group is exclusively feasible via the respective, machine-specific control consoles 8 a - 8 d (simple machine terminals 9 a - 9 d ), while the second group is possible only by means of the elements of the central control console 4 which is shown as a one-part, stationary apparatus.
Thus, for example, as concerns the three draw frames 2 a , 2 b and 2 c , the following division of control and display functions between the superordinated control console 4 and the machine-specific control consoles 31 (only one shown in FIG. 8) may be effected:
Only the following data are indicated at the display apparatus 5 of the central control console 4 : as operating data: the initial tensions, the useful effect and the standstill periods; in connection with the quality of the drafting limits: the sliver fineness limits, the thickened portions in the sliver, spectrograms, coiler can-related quality data; in connection with monitoring: regulating parameters, drafting limits, sliver fineness limits, thickened locations in the sliver, CV values and electronic functions.
Only at the display devices 33 of the machine-specific control consoles 31 the following are shown: start/stop, error acknowledgement, coiler can replacement.
At the display device 5 of the central control console 4 and at the display devices 33 of the machine-specific control consoles 31 the following are shown: in connection with the operational data: delivery speed, production, drafts, rpm's, reasons for standstill; in connection with quality: CV values; and in connection with monitoring: safety devices.
The following are inputted only at the inputting device 6 of the central control console 4 : draft, delivery speed, sliver fineness and quality limit values.
The following are inputted only at the inputting devices 32 (only one shown in FIG. 8) of the machine-specific control consoles 31 : start/stop, coiler can replacement.
Because of technological reasons, certain machine-setting and parameter-setting steps must be combined with complex numeric or graphic indications which stem from the purely production-specific control and must be performed directly at the machine. For an effective and economical solution of this task, the central control console 4 is constructed in two parts as shown in FIG. 4 . The first part 4 a is stationary and contains mainly a current supply 12 , the device 13 maintaining communication with the network 3 , the memory 14 , data administration as well as a computer 15 . The control and display portion 4 b is a mobile terminal separated from the stationary part 4 a . Thus, all the machines have the possibility, on the one hand, to receive mechanically at a suitable location the mobile control and display part 4 b of the central control console 4 and, on the other hand, to couple the mobile part 4 b electrically with the machine computers 11 a - 11 d (FIG. 2 ), 11 (FIG. 7 ), 30 (FIG. 8) which are also connected with the stationary part 4 a of the central control console 4 via the network 3 .
As shown in FIG. 5 a , the “not production-specific control” is performed by the superordinated control console 4 , but, in contrast to FIG. 4, in such a manner that the mobile terminal 4 b , disconnected from the stationary part 4 a , is associated with one of the machines.
FIG. 5 b shows an embodiment in which a mobile terminal 4 b is associated with a machine and takes care of the “not production-specific control” via a high performance machine computer 11 .
The above-outlined arrangements result in the following advantages:
a. Each machine disposes of all devices, but only of such devices, which are necessary for a “normal” production-specific machine control. The control console 8 required for this purpose may be relatively simple and economical.
b. The machine control is optimally coordinated with the machine operator and his/her tasks based on the display 10 and the overall control. In particular, the displays and information should be available independently from language, if possible, and only those keys should be available which are required for the respective control step.
c. At the superordinated control console 4 (central station) predetermined settings may be done effectively and in a simple manner. This applies, for example, to the inputting of the same preliminary data for several machines (machine group), to a take-over of parameters and settings from the machines, to a comparison of data and results, etc. By virtue of the fact that the control console 4 , as a rule, may be used for a large number of machines, the technical outlay may be overall somewhat higher and may be optimally adapted to requirements.
d. By virtue of the possibility to nevertheless perform, if necessary, all machine-settings, parameter-settings and data recall required directly at the machine, with the aid of the mobile terminal 4 b together with a corresponding graphic support, no appreciable disadvantages in the control are experienced. This is particularly so, because, as a rule, these tasks are performed deliberately and occur relatively seldom as related to the “normal operation”. Further, it is almost impossible that these tasks are performed simultaneously at several machines.
e. By virtue of the small number of utilized complex structural groups, the risk of outage as well as the required spare part acquisition are significantly reduced.
f. Overall, by virtue of the system according to the invention, a practical and substantially cost-optimal solution is found without significant technical or technological limitations.
g. If very large manufacturing systems are required or are present, more than one mobile control console 4 a may be used; in an extreme situation a separate one may be used for every machine.
h. The central control console 4 is a personal computer for industrial use, having a mobile control component. In this manner it is possible to perform all tasks for which corresponding devices and special instruments are required, such as, for example, the parameter-setting of digital driving components.
i. The control console 4 is further connected via a suitable device, such as a modem 16 (FIG. 6) with a telephone or other communication network 17 to make it possible to call for external information concerning the machines or to transfer data thereto (telephone service for problem searching, technical support, updates, and the like).
j. With an appropriately equipped central station 4 and/or the computers 11 , 11 a - 11 d and 30 it is possible, for example, to effect via the Internet a direct access to the machine control or assistance, or to gain access to externally stored drawings, graphs, and the like. It is advantageous to make available, maintain and store such information centrally, and then make them available for worldwide locations.
k. The central control console 4 is constructed such that it is capable of transmitting reports via the ordinary telephone network 17 or other communication networks to one or several arbitrarily designated communication devices in case of errors or other problems. As shown in FIG. 6, this applies particularly in case of handheld remote controls 18 (for example, by means of SMS), with which the maintenance personnel may be equipped for being contacted under predefined conditions via a transmitter 19 . Thus, such an arrangement may also assume the function of an automatic personal paging system. A transmitter station is designated at 19 .
l. In addition, the central control console 4 may control one or more signaling lamps or acoustic signaling devices. In case of a malfunction, the signal transmitters acoustically or visibly may indicate the existence of a problem and alert the maintenance personnel. A plant plan on the monitor of the central control console 4 or its mobile terminal 4 b may point to the particular machine which experiences difficulties.
m. The central control console 4 may also be coupled to further networks to thus provide the possibility to establish communication with additional desired machines and devices.
n. To avoid an unnecessary burdening of the machine computer, the machine controls 11 , 11 a - 11 d and 30 may be designed such that the mobile terminal 4 b has, when in use at the machine, a direct connection with the network which interconnects the machines.
o. The mobile part 4 b of the central handling and indicating station 4 is coupled with the stationary part 4 a by means of a serial communication (for example, CANopen, Ethernet, and the like). In this manner, it may also be coupled to the individual machine controls 11 , 11 a - 11 d and 30 .
p. The mobile terminal 4 b as well as the input at the machines are designed such that upon coupling the mobile terminal to the machine, the required electric connections are automatically established (for example, by means of a special, integrated plug-in unit).
q. The mobile terminal 4 b is designed such that it has all the usual attributes of a personal computer for industrial use.
r. The control console 4 and the mobile terminals 4 b communicate with one another by wireless or by infrared transmission. As a result, the terminal may be used even without a direct electrical connection practically at any desired location of the plant.
s. The standard machine terminal 8 (which is stationary at each machine) provides for the possibility for an operator to summon maintenance personnel (for example, by the handheld control unit 18 ) from this position, via the central control console 4 and its connection to the telephone network 17 .
t. It is of particular advantage to provide that the central control console 4 and the machines connected via the network 3 have approximately the same hardware conditions and the used operating system is the same. In this manner a very simple and problem-free data exchange may be ensured.
FIG. 7 illustrates a carding machine 1 having a feed roller 20 connected to an electronic tachogenerator 21 as measured value receiver. The tachogenerator 21 is connected to an analog-digital converter 22 which, in turn, is coupled with an electronic control device 11 (microcomputer) including a microprocessor with memory. The analog/digital converter 22 is controlled by the microcomputer 11 coupled to a nominal value inputter 23 . The microcomputer 11 is further connected to a first digital/analog power converter 24 connected with a regulating motor 25 which drives the feed roller 20 . The carding machine 1 further has a doffer 29 coupled to an electric tachogenerator 26 which functions as a measured value receiver and which is connected with the analog/digital converter 22 coupled to the microcomputer 11 . The latter is also connected to a second digital/analog power converter 27 coupled to a regulating motor 28 driving the doffer 29 . In operation the rpm signals of the feed roller 20 and the doffer 29 are converted into analog electric signals by the tachogenerators 21 and 26 , respectively. These analog signals are converted into digital electric signals by the analog/digital converter 22 and constitute the input signals in the microcomputer 11 . The microprocessor of the microcomputer 11 forms digital electric output signals from the input signals and the stored program data. These digital signals are reconverted into analog electric signals by the successive digital/analog power converters 24 and 27 , respectively, and are applied thereafter to the regulating motors 25 and 28 . The inputting device 9 and the monitor 10 , comprised in the machine-specific control console 8 (FIG. 2 ), are connected to the electronic machine control and regulating device 11 . One of the functions of the inputting device 9 is to switch the carding machine 1 on and off. The control console 8 of the carding machine 1 is connected by the data cable 3 to the central control console 4 .
FIG. 8 schematically shows a draw frame 2 in which the slivers 35 are withdrawn from non-illustrated coiler cans and enter a sliver guide 36 and pass by a measuring member 39 as they are pulled by calender rolls 37 , 38 in the working direction A. The draw unit of the draw frame 2 is a 4-over-3 construction, that is, it has a lower output roll I, a lower mid roll II and a lower input roll III as well as four upper rolls 40 , 41 , 42 and 43 . In the draw unit a drafting of the slivers is taking place, and the drafted slivers are introduced at the outlet of the draw unit into a sliver guide 44 and are, by means of calender rolls 45 and 46 , pulled through a sliver trumpet 47 in which the slivers are combined into a single sliver 48 which is subsequently deposited into a non-illustrated coiler can.
The calender rolls 37 , 38 , the lower input roll III and the lower mid roll II which are mechanically coupled to one another, for example, by means of a tooth belt, are driven by a regulating motor 49 as a function of an inputted nominal (desired) value. The upper rolls 40 and 41 are driven by friction from the respective lower rolls. The lower output roll I and the calender rolls 45 , 46 are driven by a principal motor SO. The regulating motor 49 and the principal motor 50 have a respective regulator 51 and 52 . The rpm regulation is effected by a closed regulating circuit in which the regulator 51 is connected with a tachogenerator 53 and the principal motor 50 is connected with a tachogenerator 54 . At the inlet of the draw unit a mass-proportionate magnitude, for example, the cross section of the slivers 35 is sensed by the measuring organ 39 . At the outlet of the draw unit the cross section of the exiting sliver is obtained by a measuring organ 55 integrated in the sliver trumpet 47 . A central control and regulating device 30 such as a microcomputer with a microprocessor transmits to the regulator 51 a setting of the desired magnitude for the regulating motor 49 . The measured magnitudes of the two measuring organs 39 and 55 are, during the sliver drafting step, applied to the central computer unit 30 . From the measured magnitude of the inlet measuring organ 39 and from the desired value for the cross section of the discharged sliver, the desired value for the regulating motor 49 is determined in the central computer 30 . The measured magnitudes sensed by the outlet measuring organ 55 serve for monitoring the outputted sliver. By means of this regulating system fluctuations in the cross section of the slivers 35 may be compensated for by a suitable regulation of the drafting process, that is, an evening of the sliver may be achieved. A machine-specific control console 31 which encompasses an inputting device 32 and a monitor screen 33 is connected to the electronic machine control and regulating device 30 . One of the functions of the inputting device 32 is to switch the draw frame 2 on and off. The machine-specific control console 31 of the draw frame 2 is connected to the central control console 4 by means of the data cable 3 .
The invention was described in an exemplary manner in connection with a system formed of carding machines 1 and/or draw frames 2 . It is to be understood that the invention may be utilized in a system formed of other spinning room machines, for example, flyers, spinning machines, spooling frames and the like.
The term “superordinated” characterizing the central control console 4 encompasses a functional super-ordination such that the central functions (FIGS. 3, 5 a , 5 b ) of the superordinated (central) control console 4 for the plurality of associated machines 1 , 2 , 1 a - 1 h and 2 a - 2 c are the same. The term “superordinated” for central control console 4 further encompasses a structural super-ordination such that only one control console 4 or only one mobile control console 4 b is present for the plurality of associated machines 1 , 2 , 1 a - 1 h and 2 a - 2 c . In this arrangement, the mobile control console 4 b cooperates either with the stationary control console 4 a (and its computer unit 15 ) or with the electronic machine control and regulating apparatus 11 , 11 a - 11 d and 30 of a machine 1 , 2 , 1 a - 1 h and 2 a - 2 c.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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A control system for a group of fiber processing machines includes a superordinated control console; and separate machine-specific control consoles connected to each respective fiber processing machine. The superordinated control console and the machine-specific control consoles are connected to one another by control and regulating devices via a network. The superordinated control console includes a stationary unit having arrangements for supplying current, for communicating with said network, for storing and administering data, and a computer. The superordinated control console further includes a mobile unit having an operating and displaying unit.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method and circuitry for developing a magnitude signal which represents the approximate magnitude of a control parameter vector for the control of a multi-phase electrical apparatus, such as a rotary field machine or a three-phase system.
2. Description of the Prior Art
In the control of rotary field machines and of threephase power supplies, the problem often arises of determining the magnitude of a vector (e.g. a voltage or current vector) which is defined by its coordinates. In the control of a rotary field machine, for example, a magnetizing current control produces the desired value for the magnetizing current, and an active current control the desired value for the active current, the two currents being phase-shifted by 90°, i.e., the respective vectors are perpendicular to one another. The rotary current machine is controlled with a current composed of the magnetizing current thus determined and of the active current, it being necessary to determine the magnitude of the current.
The seemingly most obvious method to use to determine the magnitude of a vector is the Pythagorean theorem. This method is, however, relatively complicated to implement with circuitry since it requires the use of two squaring components and a root evolving component. Moreover, analog squarers and root evolvers cause very high errors at small values.
Existing literature describes a circuit referred to as a "vector meter" for the formation of the magnitude of a vector. This circuit operates with a control loop which proceeds from a transformed formulation of the Pythagorean theorem. It requires two adders and a multiplier with division input. Analog dividers, however, are relatively complicated, and have limited accuracy at small values.
Another known possibility is the formation of the magnitude of a vector by approximation using the so-called "characteristic curve" method, which is employed in commercially available equipment. The characteristic used for this method is shown in FIG. 1. The x-coordinate V X of a vector V is plotted on the abscissa, and its magnitude | is plotted on the ordinate. The characteristic consists of a group of lines parallel to the ordinate with the y-coordinate of the vector V as parameter, and of the bisectors of the coordinate system. As long as the coordinates of the vector V lie in the zone of the group of straight lines, the y-component of the vector V is used in accordance with these lines as the magnitude | of the vector. For vector coordinates outside the group of lines, the magnitude | of the vector is determined from the x-coordinate by way of the respective bisector, that is, the x-coordinate is used as the magnitude. Since the group of lines of the characteristic comes into play when the y-coordinate of the vector V is greater than its x-coordinate, what the characteristic curve method amounts to in the last analysis is that the greater of the two coordinates of the vector V is chosen as the magnitude of the vector. The accuracy of this method, however, is very low. The maximum occurring error is about 30% and occurs when the two coordinates of the vector V are identical.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved method for determining the magnitude of a vector for the control of multi-phase electrical apparatus, whose accuracy can be selected and which can be implemented without the need for divider elements.
It is a further object of the invention to provide circuitry for implementing the method of the invention.
According to one aspect of the invention, an approximate value for the magnitude of a vector V is achieved by forming at least one auxiliary vector V i which has the same length as the vector V but which is rotated by an angle α i relative thereto; and selecting as the value for the magnitude of the vector V the maximum value of the coordinates of the vector V and the auxiliary vector or vectors V i . In this method of magnitude determination, the absolute value formation is effected by a vector rotation which is easily realizable and by a maximum value selection. The method becomes more accurate, the more auxiliary vectors that are formed. The accuracy is thus controllable at will be selecting the appropriate number of auxiliary vectors.
Advantageously, the approximate value for the magnitude of the vector V is taken as the maximum value of corresponding ones of the coordinates of the vector V and the auxiliary vectors V i . In this case, it suffices to evaluate only one coordinate. Any reduction of accuracy due to ignoring the other coordinate can be compensated for by increasing the number of auxiliary vectors formed.
For n auxiliary vectors V i formed for a vector V which is given in a Cartesian coordinate system, they are appropriately rotated relative to the vector by the angle α i =90°/(2n+1)·2i. For an established number of auxiliary vectors, rotation by this angle results in the optimum accuracy.
If for a vector V given in a Cartesian coordinate system n auxiliary vectors V i are formed, these may be rotated relative to the vector also by the angle ##EQU1## and the approximate value for the magnitude of the vector V may be taken as the maximum value of corresponding ones of the coordinates of the auxiliary vectors V i . In this case, the optimum angle of rotation is different, since the coordinates of the vector itself are not included in the maximum value selection.
Vectors lying in any quadrant of the coordinate system can be readily transformed into the first quadrant by absolute value formation of the two coordinates.
Coordinates of vectors not present in the Cartesian coordinate system are expediently transformed before the absolute value formation into Cartesian coordinates by coordinate transformation. This is because the operations required for the method of the invention can best be carried out in the Cartesian coordinate system.
In another aspect of the invention, a circuit arrangement for the practice of the method is provided wherein a magnitude signal representing the approximate magnitude of a vector V is developed from coordinate signals that represent the Cartesian coordinates of the vector V. A coordinate signal is formed for each of a plurality of auxiliary vectors V i , by applying proportionate parts of each of the vector V coordinate signals by means of a proportional stage as inputs to an adder stage. The outputs of the adder stages, and optionally also one or both vector V coordinate signals, are then applied to a maximum value selection circuit which selects the largest of the auxiliary vector V i coordinate signals (and one or both of the vector V coordinate signals if desired) as the usable vector V magnitude signal. The method of the invention is thus readily implemented by circuitry comprising simple proportional stages, adder stages and a maximum value selection circuit.
An especially simple maximum value selection circuit comprises a plurality of diodes, respectively connected at their one terminals to receive the auxiliary vector coordinate output signals from the adders (and, optionally, to receive one or both of the vector V coordinate signals) and connected at their other ends to a common maximum value selection circuit output terminal.
The accuracy of the maximum value selection circuit can be increased by providing as the proportional and adder stages for each auxiliary vector, an operational amplifier having a first input connected to receive the reference potential of the circuit arrangement and a second input connected to receive the x- and y-coordinates of the vector V through respective first and second resistors. A first diode is connected between the second amplifier input and the amplifier output, and a second diode is connected between the amplifier output and the maximum value selection circuit output terminal that is common for the separate circuits of each auxiliary vector and at which the desired approximate value is developed. This latter circuit provides maximum value selection without the diode thresholds found to be disturbing in single diode circuits.
There have thus been outlined rather broadly certain objects, features and advantages of the invention in order that the detailed description that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described more fully hereinafter. Those skilled in the art will appreciate that the conception on which this disclosure is based may readily be utilized as the basis for the designing of other arrangements for carrying out the purposes of this invention. It is important, therefore, that this disclosure be regarded as including all such equivalent arrangements that encompass the spirit and scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention have been chosen for purposes of illustration and description, and are shown in the accompanying drawings forming a part of the specification, wherein:
FIG. 1 (prior art) illustrates an example of the prior art characteristic curve method of vector magnitude approximation.
FIG. 2 illustrates an example of the auxiliary vector formation method of vector magnitude approximation in accordance with the invention.
FIG. 3 is a block diagram of circuitry used to implement the method of FIG. 2.
FIG. 4 is a schematic diagram of an embodiment of part of the circuitry of FIG. 3.
FIG. 5 is a schematic diagram of a modified form of the part of the circuitry of FIG. 3 shown in FIG. 4.
FIG. 6 is a schematic diagram of an embodiment of a different part of the circuitry of FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The principles of the method according to the invention are illustrated with respect to the example given in FIG. 2. In FIG. 2, a vector whose magnitude | is to be determined is shown represented in the first quadrant of a Cartesian coordinate system by x- and y-coordinates.
It is assumed that the vector V is already present in the first quadrant of the Cartesian coordinate system. Vectors which do not lie in the first quadrant can be projected into the first quadrant by absolute value transformation of their Cartesian coordinates. Vectors defined in oblique or other coordinate systems, e.g. in the 120° coordinates of a multi-phase current system, can be transformed into the Cartesian coordinate system by means of well-known coordinate transformation techniques.
In the example of FIG. 2, three auxiliary vectors V 1 , V 2 and V 3 are formed from the vector V. The auxiliary vectors V 1 -V 3 have lengths that coincide with the length of the vector V and are rotated relative to the vector V by the respective acute angles α 1 α 2 and α 3 .
An approximation of the value of the magnitude | of the vector V can then be obtained by forming either the maximum value of the x- and y-coordinates of the vector V and of the auxiliary vectors V 1 -V 3 , or the maximum value of only one coordinate of the vector V and of the auxiliary vectors V 1 -V 3 . Alternatively, a maximum value selection can be performed which entirely omits any consideration of the coordinates of the vector V.
In the example of FIG. 2, only the y-coordinates are made use of for the absolute value formation. Using only one coordinate has the advantage that the second coordinate of the auxiliary vectors V 1 -V 3 need not be determined. And using the y-coordinate has the advantage that, in contrast to the x-coordinate, the y-coordinate of the auxiliary vectors V i cannot be negative for any vector V lying in the first quadrant and angles α 1 -α 3 which are smaller than 90°. The desired approximate value for the magnitude of the vector thus equals the maximum of the y-coordinate of the auxiliary vectors V 1 -V 3 and, optionally, of the vector V. Hence in the example, the desired approximate value equals V 3y --the y coordinate of the auxiliary vector V 3 .
The accuracy of this method depends on the correct selection of the angles α 1 -α 3 and on the number n of auxiliary vectors V 1 -V 3 formed from the vector V. The following law of formation for the angles of rotation α i furnishes the best results when one does not include the y-coordinate of the vector V in the maximum value selection: ##EQU2##
For n=3, therefore, the angles of rotation of the auxiliary vectors V 1 -V 3 relative to the vector V are: α 1 =15°; α 2 =45°; and α 3 =75°. As is clear from the example shown in FIG. 2, these are the optimum angles of rotation. In fact, the greatest error occurs when the angle between the y-axis and the nearest auxiliary vector V i is greatest. As an analysis of FIG. 2 indicates, this angle cannot become greater than 15° at the stated selection of the angles α 1 -α 3 . The maximum error occurs when the vector V lies on the x-axis.
Following this reasoning, the maximum error F max occurring in the example can be calculated as follows:
F.sub.max =-(1-cos 15°)·100%=-3.4% (2)
For the general case of n auxillary vectors
F.sub.max =-[1-cos (45°/n)] (3)
From the above reasoning, it follows that the error is always negative, i.e. that the approximate value for the vector magnitude will never become greater than the actual vector magnitude. Therefore, by multiplying the obtained approximate value by a constant "a", so that the error is symmetrical around zero, one can reduce the maximum error to ±1.7%. This factor a is derived from the following reasoning:
The mean value of the approximate value | is: ##EQU3## where | is the actual magnitude of the vector V. Now if the approximate value |' obtained by the described method is multiplied by a factor a such that its mean value equals the actual magnitude of the vector V, (i.e., so that the approximate value coincides with the actual magnitude | not at its maxima as before but at its mean value), then the above-mentioned symmetrical error can be obtained with this factor a. The factor a is obtained, therefore, according to the following equation: ##EQU4## The above reasoning shows that even with the formation of as few as three auxiliary vectors V 1 -V 3 , an error as small as ±1.7% is obtainable. The method according to the invention offers the special advantage that this error does not increase at small magnitudes as is the case with methods using a dividing step.
Naturally, numerous variants of the described method are conceivable. For example, the x-coordinate of the vector V, the y-coordinate of the vector V, and also the x-coordinates of the auxiliary vectors V i can be included in the maximum value selection, whereby the law of formation for the optimum angles of rotation changes and the accuracy becomes greater.
If, for example, the magnitude of the vector V is formed from the y-coordinates of the auxiliary vectors V i and of the vector V, the optimum angles of rotation are defined by: ##EQU5## In this case, the greatest angle between the y-axis and the nearest auxiliary vector V i for three auxiliary vectors is 12.9°, as compared to an angle of 15° where the y-coordinate of the vector V is not considered. Hence, the accuracy of the method is increased.
Circuitry for the practice of the described method is shown in FIGS. 3-6. FIG. 3 is a block diagram of a usable circuit arrangement. The coordinate signals V u and V w represent the coordinates of vector V, present in any oblique coordinate system. These signals are transformed by means of a coordinate transformer KW (FIG. 3) into signals V x ', V y ', representing the equivalent coordinates of the vector in the Cartesian coordinate system. By means of the component G1, the vector V is then rotated into the first quadrant of the Cartesian coordinate system. This is done simply by taking the absolute value of the coordinate signals V x ' and V y ', such as by rectifying them. A vector V in the first quadrant of the Cartesian coordinate system is thus defined by the coordinate signals V x , V y . The approximate magnitude |' of the vector V is formed by the circuit B.
FIG. 4 shows the details of an embodiment of the circuit B used for developing a magnitude signal to represent the approximate magnitude of the vector V defined by the absolute value Cartesian coordinate signals V x , V y . In accordance with the described methods, auxiliary vector coordinate signals are formed which represent at least one of the coordinates of a plurality n of auxiliary vectors V i which have the same magnitude as the vector V but are rotated by different angles relative thereto.
The following vector equation for the rotation gives the y-coordinate of an auxiliary vector V i formed by rotating the vector V through an angle α i :
V.sub.iy =V.sub.x ·sin α.sub.i +V.sub.y ·cos α.sub.i (6)
As in the example of FIG. 2, the embodiment of FIG. 4 considers three auxiliary vectors V 1 , V 2 , and V 3 which correspond to rotation of the vector V through the angles α 1 , α 2 and α 3 respectively. The angles α 1- α 3 are advantageously defined, as described above, as α 1 =15°, α 2 =45°, α 3 =75°. Signals are formed corresponding to the y-coordinates only (V 1y , V 2y , and V 3y ) of the auxiliary vectors V 1-V 3 . These are determined applying rotational coordinate transformation equations to the coordinates V x , V y of the vector V, as follows:
V.sub.1y =C.sub.1 ·V.sub.y +C.sub.4 ·V.sub.x (6a)
V.sub.2y =C.sub.2 ·V.sub.y +C.sub.5 ·V.sub.x (6b)
V.sub.3y =C.sub.3 ·V.sub.y +C.sub.6 ·V.sub.x (6c)
where, the constants C 1 -C 3 which are multiplied by the y-coordinate signal of vector V are defined by:
C.sub.1 =cos α.sub.1 =cos 15°=0.966
C.sub.2 =cos α.sub.2 =cos 45°=0.704
C.sub.3 =cos α.sub.3 =cos 75°=0.258
and the constants C 4-C 6 which are multiplied by the x-coordinate signal of the vector V are defined by:
C.sub.4 =sin α.sub.1 =sin 15°=0.259
C.sub.5 =sin α.sub.2 =sin 45°=0.704
C.sub.6 =sin α.sub.3 =sin 75°=0.966
Since the y-coordinates of the vectors V 1-V 3 are obtained by simple multiplication and addition, the contributions of the y-coordinate signals (C 1 V y , C 2 V y and C 3 V y ) and x-coordinate signals (C 4 V x , C 5 V x and C 6 V x ) of the vector V to the y-coordinate signals of the vectors V 1-V 3 can be obtained respectively using simple proportional stages 1a, 1b, 1c and 2a, 2b, 2c, respectively (FIG. 4).
The V x and V y signal components of the auxiliary vector coordinate signals are then combined by adders 3a, 3b and 3c, connected as shown in FIG. 4, to provide the y-coordinate signals of the vectors V 1-V 3 . The proportional stages and their associate adder stages can be implemented by means of operational (summing) amplifiers.
In accordance with equations (6a)-(6c), the outputs of the proportional stages 1a and 2a are connected as inputs to the adder stage 3a; the outputs of the porportional stages 1b and 2b are connected as inputs to the adder stage 3b; and the outputs of the proportional stages 1c and 2c are connected as inputs to the adder stage 3c. According to the described method, the circuitry of FIG. 4, provides means for selecting the maximum of the auxiliary vector y-coordinate output signals of the adder stages 3a-3c and also (optionally) the y-coordinate signal V y of the vector V.
This is done in the simplest case (see FIG. 4) by connecting the mentioned signals via diodes 4a-4d with a common point which is connected via a resistor 11 to the reference potential of the circuit arrangement and is connected with the output terminal A of the circuit arrangement. The diodes 4a-4c operate so that only approximate value |' for the magnitude of the vector V is available at the output terminal A.
FIG. 5 shows the details of a modified form of the circuit of FIG. 4 which avoids the disadvantage of adverse effects caused by the thresholds of the diodes 4a-4d of FIG. 4 on the accuracy of the circuit arrangement.
In the embodiment of FIG. 5, the proportional stages 1a-1c and 2a-2c together with the adder stages 3a-3c and the maximum value selection circuit 4 are realized by means of operational amplifiers 5a-5c. Here the noninverting input of each operational amplifier 5a-5c is connected to the reference potential of the circuit arrangement. The inverting inputs of the operational amplifiers 5a-5c are respectively connected by means of the resistors 6a-6c to receive the negative x-cooridinate signal V x of the vector V and by means of other resistors 7a-7c to receive the negative y-coordinate signal V y of the vector V. Diodes 8a-8c are respectively connected between the inverting inputs and the outputs of the operational amplifiers 5a-5c with their cathodes facing the outputs. The outputs of the operational amplifiers 5a-5c are also respectively connected through diodes 9a-9c to a common connecting point P, which is in turn connected with the output A of the circuit arrangement. The diodes 9a-9c are connected with their cathodes toward the point P. In addition, resistors 10a-10c are respectively connected between the inverting inputs of the operational amplifiers 5a-5c and the common connecting point P.
In the embodiment according to FIG. 5, in contrast to the embodiment according to FIG. 4, the y-coordinate of the vector V is not evaluated, since here a separate operational amplifier would be necessary for the maximum value selection.
Without the connection with the common connecting point P, the output of each operational amplifier 5a-5c would adjust itself to a voltage proportional to the sum of the coordinates V x , V y as a function of the ratio of the resistances of the resistors 6a-6c, 7a-7c and 10a-10c. The values of the resistors 6a-6c, 7a-7c and 10a-10c must therefore be selected to give the proportionality factors C 1 -C 6 , defined above.
The diodes 9a-9c and 8a-8c have no influence on the magnitude of the output voltage, which depends only on the resistors. They merely provide that when the outputs of the operational amplifiers 5a-5c are connected with the common connecting point P, only the maximum of the output voltages, i.e. the greatest y-coordinate of the auxiliary vectors V 1 -V 3 , appears at the output A. Hence, there is present at the output A the desired approximate value for the magnitude of the vector V, which in this case is independent of the threshold voltages of the diodes.
Finally, FIG. 6 shows an embodiment of the coordinate transformer KW. If, for example, it is desired to transform the coordinates V u , V w given in a 120° coordinate system into rectangular Cartesian coordinates V x ', V y ', one can proceed according to the following equations: ##EQU6##
In the circuit according to FIG. 6, these equations are realized in that the coordinate V u is taken over unchanged as the x-coordinate V x '. Moreover, one supplies the coordinate V u via a proportional stage 12a with the proportionality factor b1 and the coordinate V w via a proportionality stage 12b with the proportionality factor b2 to an addition stage 13, at the output of which the y-coordinate V y ' is available. According to equation (7), the proportionality factor b1 is 1/√3 and the proportionality factor b2 is 2/√3 . Naturally, the coordinate transformer KW and also the circuit Gl for rotation of the vector V into the first quadrant of the Cartesian coordinate system may be omitted if the vector V is already present in suitable form.
Having thus described the invention with particular reference to the preferred forms thereof, it will be obvious to those skilled in the art to which the invention pertains, after understanding the invention, that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the claims appended hereto. It will be appreciated that the selection, connection and layout of the various components of the described configurations may be varied to suit individual tastes and requirements.
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A magnitude signal representing the approximate magnitude of a control parameter vector for the control of multi-phase electrical apparatus is developed from the Cartesian coordinate signals of the vector. Signals representing one or both coordinates of a plurality of auxiliary vectors are formed by vector rotation coordinate determination techniques. The signal from among the auxiliary vector coordinate signals (and, optionally the control parameter vector coordinate signals) having the greatest absolute value is selected as the magnitude signal. Auxiliary vector coordinate signals are formed by proportional stages coupled to adder stages which combine specified constant proportions of the control parameter vector coordinate signals. A diode network provides biasing so that only the signal with the greatest value will be passed. The auxiliary vector forming method for vector magnitude approximation provides accuracy and simplicity.
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RELATED APPLICATIONS
This application is a continuation in part of U.S. application Ser. No. 11/446,951, filed Jun. 5, 2006, which is a continuation of U.S. Pat. No. 7,076,941 the disclosures of which are hereby incorporated by reference herein.
TECHNICAL FIELD
The present invention relates to externally heated engines. More particularly, the present invention relates to improvements in the efficiencies of externally heated engines operating at relatively low temperatures and pressures.
BACKGROUND OF THE INVENTION
Externally heated engines and, in particular, Stirling cycle engines have always held great promise, because their theoretical thermal efficiency approaches that of the Carnot Cycle. This efficiency is established in turn by the difference between the hot and cold temperatures of the cycle. Recent designers of such engines have sought to maximize efficiency by increasing the temperature of the hot side of the engine. In addition, they have utilized fine molecule gasses, such as helium and hydrogen, at very high pressures, to further optimize the power output of the engine. Their combined efforts have resulted in commercial failure. The high temperatures have required the use of materials which can withstand these temperatures. The practical problems, and enormous expense, of using materials such as titanium and special alloys of stainless steels have combined to make the engines impractical to manufacture, and expensive to own and operate. High pressure gasses and extreme temperatures have made the engine so complex that it has been placed out of the reach of all but the most sophisticated users.
The present invention takes a completely opposite approach. Through the combined use of several innovations, the design of a high efficiency, low temperature, simple engine becomes possible.
To overcome the inefficiencies of engines of the past, the temperature differential between the air outside the cylinder, and the working fluid inside the cylinder must be very large to force the transfer of the necessary amount of heat in the very limited time available. This in turn forces the heat source itself to operate at an even higher temperature, and to be very tightly coupled to the heat exchanger. This tends to expose the external portions of the exchanger to even higher temperatures, which requires still more exotic materials.
An additional problem in the prior art engines concerns the temperature of the air sent to the regenerator. The extreme temperatures traditionally involved in the prior art make the use of common low temperature tubing, such as copper, impossible. This also applies to the materials used in the regenerator. Neither the outside of the regenerator or the material used in the regenerator matrix can be optimized for thermal performance, because the overriding concern is survivability at high temperature.
The problems of high temperatures completely dominate the design of a regenerator to be used in the prior art Stirling engines. This leads to significant thermodynamic losses, as well as greater expense, and reduced lifespan. The outside shell of the regenerator has to be made of high strength metals that will tolerate the high temperatures. This leads to high losses of heat to the environment, heat gained from the environment, and heat conducted from one end of the regenerator to the other. This heat conduction forces operation of the regenerator in a manner that is far from ideal.
The heat exchanger on the cold cylinder must efficiently remove heat from the working fluid, during the compression stroke. As with the hot side, prior art heat exchanger designs have used either the basic cylinder shape itself as the heat sink, or they have used simple finned surfaces or some variation of the shell and tube heat exchanger. In all such designs, the thermal resistance inherent in these approaches forces the heat sink to operate with a large difference in temperature (ΔT) between the interior and exterior of the cylinder.
In other words, the working fluid inside the cold cylinder is forced to be at a temperature considerably above the outside temperature at which the heat is finally dissipated. This greatly reduces the ΔT across the engine, which limits the maximum efficiency and power output of the engine.
Since the Stirling Cycle is a closed thermodynamic cycle, the working fluid must be sealed inside the engine. This leads to several major design problems.
First, the prior art engines are forced to operate at high temperatures and pressures. This places great demands on the seals. To survive the high temperatures and pressures, the only practical approach has been to use sealing rings on the piston, as in conventional internal combustion engines. The piston and ring assemblies suffer leakage, or blow-by. This fluid loss from the engine is a critical problem, as it must continually be replaced to avoid loss of power output, and it disturbs the cycle. This usually means that the crankcase itself must be sealed as well, leading to problems of lost work in the crankcase, as the pistons do unwanted work on the crankcase gas. It also means that the crankcase must be filled with the same working fluid as used in the engine itself.
The piston rings scraping up and down on the walls of the cylinder lead to further problems. The biggest of these is the friction created. In a typical engine this can consume some 20% of the engine's output, a very serious loss.
A further problem is that of lubrication. Liquid oils cannot be simply sprayed onto the cylinder walls, as this would leak into the working area of the engine and contaminate the working fluid. This would lead to problems involving unwanted contamination, corrosion, and loss of efficiency. But without adequate lubrication, the friction losses become even greater.
Another problem with engines of the past is that a large proportion of the working fluid does not move fully throughout the engine. An engine is needed which increases the amount of working fluid which participates in the process.
Additionally, an engine is needed which has a variable compression ratio to allow for maximizing the power output depending on the temperature of the heat source used to power the engine. An engine is also needed which has variable timing to optimize power output at various temperature, pressure and engine speed conditions.
The present invention solves all these problems found in the prior art designs.
SUMMARY OF THE INVENTION
Briefly described, the present invention includes an externally heated engine having a piston and a displacer. A piston reciprocates within a first cylinder. The piston has a first side (working side) and a second side opposite the first side. The first side of the piston and the first cylinder define a working chamber containing working fluid, which may consist of any usable gas. The second side of the piston and the first cylinder define an opposite chamber containing an opposing fluid.
A displacer reciprocates within a second cylinder. A heater heats the working fluid in the hot chamber of the cylinder of the displacer. Preferably, the chamber is heated by a heat source so that the working fluid has a temperature of no more than 500° Fahrenheit with a temperature difference between the heat source and the working fluid of less than 5° Fahrenheit. It is possible to generate useful energy with working fluid temperatures of less than 212° Fahrenheit. One source of heat is the cooling pools of spent nuclear fuel, which are below 212° Fahrenheit. Currently, this potential source of energy is released to the atmosphere and not used. The working fluid may be heated with a heat exchanger or heat injector. Heated fluid is delivered to the heat injector and flows through grooves around thermally conductive material, thus injecting heat directly into the engine. The heat is trapped inside the engine by the thermally insulating material. The working fluid flows in the longitudinal direction through the thermally conductive material. The thermally conductive material has passageways so that the working fluid may pass longitudinally through it. The longitudinal passages for the working fluid are narrow and run the entire-useable length of the heat injector.
Preferably, the heat injector has grooves for the heated fluid which include multiple, parallel grooves which form a spiral or helical pattern along the entire outside useable length of the heat injector. The spiral grooves could be in sets of 2, 3, 4 or more, running parallel to one another and into which the heated fluid is injected simultaneously. By keeping these grooves very narrow and deep, a very high value of length to depth and thus low temperature differential is achieved, while providing adequate useable cross-sectional area to permit a sufficient volume of heated fluid to flow and provide heat input. The temperature difference between the heating fluid and the metal of the heat exchanger will be only about 5 degrees Fahrenheit.
Preferably, the engine includes a diaphragm associated with the piston to separate the working chamber from the opposing chamber. The diaphragm provides many benefits as will be described in detail below. Because of the use of the diaphragm, it is beneficial to control the pressure of the opposing fluid. This prevents a large pressure differential across the diaphragm, which, if uncontrolled, could cause it to burst. A second reason is to vary the pressure on the opposing side in concert with the action of the engine's throttle control. That is, as working fluid pressure is raised and lowered, the same is done with the opposing fluid, to avoid doing unwanted work on the gas in the opposing chamber and to protect the diaphragm.
The working fluid pressure is controlled as a means of throttling the engine. As more working fluid is forced into the engine, by increasing its pressure with the control system, the engine will increase its power output, because the greater volume of working fluid will transfer more heat into and out of the engine cycle and thus do more work. Reducing the pressure will have the opposite effect. In this way, engine output can be continuously varied, to match the load conditions.
In displacer type engines, in order to force the greatest possible percentage of the working fluid in the engine to participate effectively in the thermodynamic process, as much fluid as possible must be swept alternatively all the way through the engine, from hot side to cold side and back again. This is obtained by making the volume of the displacer very large in comparison to the rest of the volume of the engine. This ensures that the vast majority of working fluid contributes effectively to the process.
The working fluid moves between the hot and cold chambers of the cylinders in a closed fluid path. A closed fluid path means that during normal operation, fluid reciprocates between the chambers, compared to a internal combustion engine, for example, which continually intakes combustion air and exhausts combustion byproducts to the atmosphere. The closed fluid path in the present invention does allow for the introduction of additional working fluid when necessary and for pressure.
A pressure differential is maintained between the working fluid and the opposing fluid in the first cylinder of between 5 to 35 psi. By maintaining pressurized opposing fluid, a higher working fluid pressure is possible while maintaining the integrity of the diaphragm. In addition, the opposing fluid aids in the compression stroke by reducing the work necessary to compress the working fluid. However, the pressure of the opposing fluid is not so high that it interferes with the power stroke. Preferably, the opposing fluid pressure is maintained between the minimum and maximum working fluid pressure. Ideally, the opposing fluid pressure is maintained at the mean of the minimum and maximum working fluid pressure. The externally heated engine may have the working fluid at a pressure of below 10 atmospheres. The externally heated engine may have the working fluid at a pressure of greater than 60 PSI.
A regenerator is provided within the closed fluid path. The regenerator is a temporary repository of heat during certain cycles of the engine. Because the temperatures are lower than in engines of the prior art, the present invention may employ a shell made out of polytetrafluoroethylene material. This material does not conduct heat. Thus there is no thermal short circuit around the mesh. In prior art regenerators operating at extremely high temperatures, only all-metallic internal components could be used. Since each layer of such metallic mesh touched both adjacent layers, a continuous, thermally conductive path was established from the hot side of the regenerator to the cold side. This resulted in a continuous loss of high temperature energy over to the cold side.
In the present invention, the regenerator operates at low enough temperatures to allow the introduction of non-metallic layers of mesh. Preferably, non-metallic mesh layers are used after every 10 or so metal layers. These non-conductive layers break up the conductive path, and thus prevent the unwanted loss of energy from the hot side to the cold side of the regenerator. In addition, since the non-metallic mesh layers can be made, for example, of woven fiberglass, they have enough thermal capacity to add slightly to the heat retention capacity of the regenerator, further adding regenerating action without adding unwanted, unswept volume.
Preferably, in addition to the metallic mesh layers and insulating mesh layers in the regenerator, a third type of layer is used. Specifically, a thicker, copper layer, which is solid with a pattern of larger openings can be used. The openings are arranged to break up and redistribute the air flow within the regenerator to ensure that the entire mesh content is fully utilized efficiently. The thicker copper also retains some additional heat, which adds further to the regenerating capacity. The regenerator does not need stainless steel wire in the mesh as with prior art regenerators, but may include copper wire, which is far more thermally conductive than steel. Silver may be used as an alternative to copper, for even higher performance. The copper mesh may be coated with diamond and may include a high melting point thermal insulating polymer such as polytetrafluoroethylene in the form of an outer cylinder and a center core. The regenerator may include a perforated disk constructed from a diamond copper composite. These choices allow the use of less mesh, with a consequent reduction in pumping losses. Alternatively, a regenerator with a series of tube segments separated by insulating material, such as, for example, fiber glass can be used. The tubes could be, for example, copper, silver, diamond coated metal, or combinations thereof.
The engine operates in the following manner. The heat applied to the hot side causes the working fluid, such as air, methane or another gas, to rise in pressure, and to expand. This forces the piston to move, thus doing useful work. The working fluid is then passed through the regenerator, on its way to the cold side. In the process it leaves behind much of its heat, which is temporarily stored in the regenerator mesh matrix. The fluid thus arrives in the cold side much reduced in temperature.
Once in the cold side, the fluid is compressed back to its original, smaller volume. This requires the removal of some heat, which is preferably rejected to a recuperator. This heat is thus recovered and reused.
Finally, the fluid passes back through the regenerator to the hot side. On the way it picks up the heat left behind in the regenerator mesh matrix. The fluid thus arrives in the hot cylinder at a much increased temperature and pressure. As further heat is added through the hot heat injector or exchanger, the fluid again enters an expansion process, thus beginning a new cycle of the engine. The piston and the displacer are arranged to reciprocate such that the volume of the working fluid is compressed and expanded alternately.
The externally heated engine may include a diaphragm attached to the piston to create a seal between the piston and the cylinder. The diaphragm may be a two layers of thin rubber separated by a woven mesh layer to increase the strength of the diaphragm. This diaphragm has virtually zero friction and zero break-away force. The diaphragm has a low melting temperature. Leakage is so slow as to be negligible. The unit is low cost, and will give up to a billion cycles in service.
The reason such a diaphragm can be employed in an externally heated engine is because of low temperature and pressure in the present invention. Without this, the high temperatures and pressures make the use of a diaphragm impractical. In prior art designs, a diaphragm would have to be made partly of thin, high temperature metals, with heat shielding. This would greatly increase friction and reduce service life, negating advantages of the diaphragm.
However, with the present invention, the diaphragm makes it possible to eliminate the main source of friction in the engine. That is, the piston rings are eliminated. A prior art Stirling engine will lose at least 20% of its output power to friction. The great majority of this friction is eliminated with the present invention. The diaphragm also eliminates the problem of leakage which is present with traditional piston ring seals. Because there is no leakage, the working fluid and opposing fluid do not mix, so that the working fluid does not become contaminated by the opposing fluid if those two fluids are not the same. The working fluid and opposing fluid need not be the same because of the perfect seal provided by the diaphragm. An opposing fluid such as dry nitrogen could be used, for example, to avoid oxidation and contamination of the volume enclosed in the bonnet. In addition, a light gas, such as helium, may be used as the working fluid, to obtain thermodynamic benefits, while still using a heavy gas such as air or nitrogen as the opposing fluid, thus avoiding the expense and difficulty of sealing the lighter gas on the opposing side, or providing quantities of it to make up for leakage.
Additionally, with the diaphragm, there is no need for lubrication in the cylinders, because the diaphragm is essentially frictionless. By eliminating lubricating oil, the working fluid does not become contaminated with lubricant.
In one embodiment of the engine, a piston is adapted for movement within a first cylinder. The piston has a first side and a second side opposite the first side. The first side and the first cylinder define a working chamber and the second side and the first cylinder define an opposite chamber containing an opposing fluid. A displacer is adapted for movement within a second cylinder. The displacer has a first side and a second side opposite the first side. The first side of the displacer and the second cylinder define a cold chamber and the second side of the displacer and the second cylinder define a hot chamber. There is a closed fluid path between the first and second cylinders which includes a working fluid. The working fluid is capable of moving between the working chamber, the cold chamber and the hot chamber. A regenerator is located within the closed fluid path. A heat source is provided for heating the working fluid. A source of cold could also be provided to cool the working fluid. A link is provided to cause reciprocation of the piston.
In some embodiments, a first disk is connected to a first shaft section and a second disk is connected to a second shaft section. A yoke can be connected to the first disk and the second disk and could be adapted for positional adjustment in the radial direction with respect to the first disk and the second disk. Preferably, the link is connected to the yoke such that positional adjustment of the yoke causes the position of the piston to change within the cylinder.
Preferably, the first cylinder has a first cylinder section and a second cylinder section, the first cylinder further includes a piston disk and a spacer disk. The piston is connected to the piston disk and the spacer disk is adapted to be attached between one of the first cylinder section and the piston disk and the second cylinder section and the piston disk. Preferably, there is a gasket adjacent the spacer disk. Additional spacers and gaskets could be used as needed. By placing spacers on one side or the other of the piston disk, the position of the diaphragm changes inside the cylinder, and thus the distance the diaphragm can travel before it hits top dead center changes. By changing the stroke of the piston, the amount of swept volume changes. Because the remainder of the volume of the engine is fixed, changing the position of the diaphragm changes the compression ratio of the engine, which is useful to accommodate various temperatures of the heat source for the engine.
In some embodiments, a displacer link is adapted to cause reciprocation of the displacer. The displacer link is connected to a displacer link disk. The displacer link disk is connected to a first shaft section and the piston link disk is connected to a second shaft section. The first shaft section and the second shaft section operably connected to each other. One of the shaft sections is operatively connected to a first disk and a second disk. The angular position of the first disk with respect to the second disk is adjustable. By adjusting the angular position of the first disk with respect to the second disk, the relative position of the displacer with respect to the piston changes. Depending on the temperature, pressure, revolutions per minute and other engine conditions, adjustment of the angular position can be used to optimize engine performance. In one embodiment, the first disk and the second disk include a plurality of bores and further include pins adapted to be inserted in the bores to fix the position of the first disk with respect to the second disk. In addition, threaded bores could be used for accepting bolts inserted through bores in at least one of the first disk and second disk.
In some embodiments, the displacer link is moved by a displacer cam assembly. The displacer cam assembly includes a first cam and a second cam. The first cam and the second cam each have a groove therein with a groove path. The displacer link is adapted to follow the groove path of the first cam and the second cam. The grove path in each of the first cam and the second cam varies in distance from the center of each cam. The displacer link can be connected to a pin and the pin can be inserted into the groove of each of the first cam and the second cam. In engines of the past, rotating crank disks impart a sinusoidal motion to the displacer. The cam assembly of the present invention can be configured to cause the displacer to dwell at the two ends of the stroke and to move rapidly from one end to the other. Preferably, the groove path has a first section which is at constant distance from the center of the cam. The groove path has a second section which is also at a constant distance from the center of the cam. The groove path makes a rapid transition between these two sections. When the pin is in each section of constant diameter, the displacer dwells at the ends of the stroke. When the pin is in the transition between these two sections, the displacer moves rapidly from one end point to the other. When the displacer dwells at the ends of its stroke, the thermodynamic cycle is squared off. By dwelling with the gas trapped in the hot end of the engine, during most of the power stroke, the gas is held as closely as possible to the ideal of an isothermal expansion with heat addition. Similarly, by causing the gas to dwell in the cold end during substantially the entire compression stroke, this part of the cycle approaches the ideal of an isothermal compression, with the heat of compression being removed.
In some embodiments, the displacer cold chamber includes a cooling element attached to the external surface of the cold chamber, which helps extract the heat of compression. In some embodiments, the displacer hot chamber includes a heating element attached to the external surface of the hot chamber, which helps replace the heat of expansion. Both the surface heating and cooling elements do not add any dead volume to the engine.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a simplified conceptual view of an engine used in connection with the present invention;
FIG. 2 is a cross-sectional view of the stroke adjustment device of the present invention;
FIG. 3 is a front elevation view of a portion of the stroke adjustment device of the prevent invention;
FIG. 4 is an end view of the device of FIG. 3 ;
FIG. 5 is a front elevation view of a portion of the stroke adjustment device of FIG. 2 ;
FIG. 6 is a side elevation view of the device of FIG. 5 ;
FIG. 7 is an exploded cross-sectional view of the piston and cylinder of the present invention;
FIG. 8 is a cross-sectional view of a timing adjustment device of the present invention;
FIG. 9 is an exploded cross-sectional view of the timing adjustment device of FIG. 8 ;
FIG. 10 is a front elevation view of a portion of the timing adjustment device of FIG. 8 ;
FIG. 11 is a front elevation view of another portion of the timing adjustment device of FIG. 8 ;
FIG. 12 is a cross-sectional view of the stroke timing adjustment device of the present invention;
FIG. 13 a is a cross-sectional view of a portion of the stroke timing adjustment device of FIG. 12 shown in a first position;
FIG. 13 b is a cross-sectional view of a portion of the stroke timing adjustment device of FIG. 12 shown in a second position;
FIG. 13 c is a cross-sectional view of a portion of the stroke timing adjustment device of FIG. 12 shown in a third position;
FIG. 13 d is a cross-sectional view of a portion of the stroke timing adjustment device of FIG. 12 shown in a fourth position; and
FIG. 14 is a simplified conceptual view of the displacer assembly of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 through 14 show the present invention. More specifically, referring to FIG. 1 a conceptual overview of the present invention is shown. A piston and displacer assembly 100 is provided which generates power. The piston assembly 110 , which is shown in greater detail in FIG. 7 includes a piston 112 which is mounted for reciprocation in cylinder 114 . At the end of the piston 112 is a diaphragm 116 . Diaphragm 116 is held in place by diaphragm disk 118 . The diaphragm 116 defines the border between the working chamber 122 and the opposing chamber 124 . The piston rod 312 facilitates reciprocation of the piston 112 and is held in proper orientation by bearing 150 . As piston 112 reciprocates in cylinder 114 , the diaphragm 116 moves within the cylinder 114 . The diaphragm 116 is attached to the front surface 136 of a piston 112 by any suitable means, such as, for example, bolt 138 and washer (not shown). The diaphragm 116 forms a frictionless seal between the working chamber 122 and the opposing chamber 124 . The piston 112 is contained in a bonnet or cylinder housing 102 . FIG. 7 shows a cross-sectional view of the piston assembly 110 .
Pushrod 312 is attached one end 314 to piston 112 and at the other end 316 to slider assembly 320 . Slider assembly 320 is adapted for linear movement. Link 322 is pivotally connected to slider assembly 320 and allows for the conversion of linear motion to rotational motion. Bearings 326 guide the movement of pushrod 312 .
As shown in FIGS. 1 and 2 the link 322 is connected to a disk assembly 410 mounted to the crankshaft 422 . The crankshaft 422 is supported by bearings 424 . The crankshaft 422 is split into multiple sections, two of which, 422 a and 422 b , are shown in FIG. 2 . The disk assembly 410 includes a novel mounting arrangement for the link 322 to allow for adjustment of the position of the piston 112 , shown in FIGS. 2-6 . The link 322 is attached to attachment bar 454 by clamp 456 . The disk assembly 410 includes a first disk 430 and a second disk 432 . The crankshaft section 422 a is connected to the first disk 430 . The first disk 430 includes bolt holes 440 . The second disk 432 is connected to the crankshaft section 422 b and includes bolt holes 442 . A U-shaped adjustment yoke 450 is attached to the first disk 430 and the second disk 432 by bolts 444 and 446 . As shown in FIG. 6 the yoke 450 has slots 452 . The bolts 444 and 446 pass through the slots 452 so that the yoke 450 can be adjusted in the vertical direction as seen in FIG. 2 . Attachment bar 454 is provided between legs 460 and 462 of the yoke 450 . The attachment bar 454 can be slid up and down by loosening the bolts 444 and 446 . As the attachment bar 454 is located further away from the crankshaft 422 , the position of the link 322 with respect to the cylinder 114 is changed.
As the position of the link 322 is changed, the position of the piston 112 in the cylinder 114 must also be changed. The cylinder 114 is designed so that the location of the piston 112 can be changed with respect to the cylinder 114 . As shown in FIG. 7 , the cylinder 114 has a first end piece 114 a and a second end piece 114 b . Between the first end piece 114 a and the second end piece 114 b are a number of spacers 130 and gaskets 132 . The first end piece 114 a , the second end piece 114 b , the spacers 130 and the gaskets 132 all have bores 160 there through to accept bolts 162 . The pushrod 312 enters the first end piece 114 a through a bearing 150 . At the terminal end of the pushrod 312 , the disk 118 holds the diaphragm 116 in place within the cylinder 114 . By moving spacers 130 and gaskets 132 from one side of the disk 118 to the other, the position of the disk 118 , and thus the diaphragm 116 is changed with respect to the cylinder 114 , effectively changing the stroke length of the piston 112 . Changing the stroke of the piston 112 changes the compression ratio of the engine.
As seen in FIGS. 1 and 14 , the engine includes a displacer or shuttle 210 , which is moved alternatively back and forth in its cylinder 214 by pushrod 218 . The displacer 210 moves the working fluid alternatively from the hot end 230 to the cold end 232 . Conduits 240 and 242 connect the displacer cylinder hot end 230 and cold end 232 to the heat injector 250 and the heat extractor 252 . Working fluid represented by arrows 254 circulates through the heat injector 250 . Cooled fluid represented by arrows 256 circulates through the heat extractor 252 . FIG. 14 illustrates, in simplified schematic form, the flow of fluid through the displacer assembly 200 of the engine. Working fluid leaves the cold side 232 of the displacer assembly 200 through the nozzle 260 as represented by the arrow 262 and enters the heat exchanger 252 . Heated fluid circulates in the heat exchanger 252 by entering the nozzle 270 and exiting the nozzle 272 . As is known in the art, the heated fluid and the working fluid are isolated from one another and do not mix. The working fluid passes through the regenerator 280 and transfers heat to the regenerator 280 . The working fluid then passes to the cold heat exchanger 250 as illustrated by arrow 282 . Working fluid enters the cold heat exchanger at nozzle 284 and exits at nozzle 286 . Again, the cold fluid and the working fluid do not mix. The working fluid enters the displacer cylinder 214 at nozzle 288 as illustrated by arrow 290 . As the displacer 210 moves in the opposite direction, the working fluid flow reverses and the process repeats. Heating elements 276 are attached to the outer surface 234 of the hot end 230 . Cooling elements 278 are attached to the outer surface 236 of the cold end 232 .
FIGS. 8-11 show a timing adjustment assembly 510 . The crankshaft section 422 b and crankshaft section 422 c are part of the timing adjustment assembly 510 . The crankshaft section 422 b is connected to a first disk 512 in bore 560 . The crankshaft section 422 c is connected to a second disk 514 in bore 562 . Pins 520 and bores 522 are provided to rotationally fix the first disk 512 to the second disk 514 . Bolts 530 and 532 are inserted through bores 534 and 536 respectively to also fix the first disk 512 with respect to the second disk 514 . The bolts 530 and 532 are threaded into bores 538 and 540 respectively. When the pins 520 and bolts 530 and 532 are removed from disks 512 and 514 , the first disk 512 can be rotated with respect to the second disk 514 . The new position of the first disk 512 with respect to the second disk 514 is then fixed by pins 520 and bolts 530 and 532 . Because shaft section 422 b and the shaft section 422 c form a single shaft 422 , the lateral position of the displacer 210 will be changed with respect to the lateral position of the piston 112 when the rotational position of the first disk 512 is changed with respect to the rotational position of the second disk 514 .
FIGS. 12 and 13 a - 13 d illustrate the displacer 210 reciprocation cam assembly 610 . The crankshaft section 422 c has a cam 612 attached thereto. Similarly, the crankshaft section 422 d has a cam 614 attached thereto. Each cam 612 and 614 has a groove 616 as best seen in FIGS. 13 a - 13 d . A pin 620 is inserted into the groove of each disk 612 and 614 . As the disks 612 and 614 rotate the pin 620 is moved radially in the direction of arrow 630 in FIG. 13 a . The link 640 for the displacer 210 is connected to the pin 620 . As the radial position of the pin 620 changes, this determines the lateral position of the link 640 for the displacer 210 and, thus, the lateral location of the displacer 210 . When the pin 620 is located at a point closest to the crankshaft 422 , the displacer 210 is at one end of its reciprocating path. When the pin 620 is located at a point farthest from the crankshaft 422 , the displacer 210 is located at the other end of its reciprocating path. FIGS. 13 a - 13 d illustrate the radial position of the pin 620 for various positions of the cam. In FIG. 13 a , the pin 620 is located nearest to the crankshaft 422 . As the cam 612 rotates to the position shown in FIG. 13 b , the pin 620 is moved radially outward. As the cam 612 continues to rotate, the pin 620 is moved to the position in FIG. 13 c , which is farthest from the crankshaft 422 . Finally, as the cam 612 rotates to the position in FIG. 13 d , the pin 620 is moved closer to the crankshaft 422 . The shape of the slot 616 determines the amount of time that the displacer 210 dwells at its end points 296 and 298 ( FIG. 14 ), and the speed at which the displacer 210 moves from one end 296 of the cylinder 214 to the other 298 . By causing the displacer 210 to dwell at the ends of its reciprocating path, and to move rapidly from end to end, the heat transfer to and from the working fluid is enhanced.
One of ordinary skill in the art will appreciate that there are many equally feasible power transmission methods and physical arrangements of the various elements described. The foregoing description is meant to provide a conceptual overview and should not be viewed as limiting the invention. While the invention has been described by reference to various specific embodiments, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the described embodiments, but will have full scope defined by the language of the following claims.
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An externally heated engine is provided which has a piston and a displacer. The position of the piston can be adjusted by a yoke and disk assembly on one end of a link and spacers and gaskets in the cylinder. The relative position of the displacer with respect to the piston can be changed by changing the relative position of a pair of disks in the crankshaft assembly. The displacer is caused to reciprocate by a link which is moved by a displacer cam assembly. The displacer cam assembly includes a first cam and a second cam. The first cam and the second cam each have a groove path. The displacer link follows the groove path of the cams to cause the displacer to dwell at the two ends of its stroke and to move rapidly from one end to the other.
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BACKGROUND
[0001] High frequency cables are required to sample signals in the gigahertz range while testing equipment and devices. These high frequency cables are fragile and easily damaged, which results in the sampled signal being degraded or disrupted. Therefore, the cables are treated with the utmost care to ensure that the cable is not kinked or damaged. As the cost of these cables can be in the hundreds of dollars, it is not economically viable to be constantly replacing damaged cables.
[0002] The high frequency cables may be affixed to test probes and connected to test equipment, but the transmitted signal must also be routed through the device itself using the same kind of high frequency cable. There exists a delicate balance between protecting the internal cable(s) and packaging the test equipment within a housing. The cable(s) may snake between the various internal components to reach a termination point that may be located a circuitous path away from the probe connection. The cables are routed carefully through the housing to avoid kinking and damaging the cable on its path through the device.
[0003] Embodiments of the disclosed technology address these needs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is an exploded perspective view of an embodiment of the cable restraint device.
[0005] FIG. 2 is a perspective view of the base plate used in conjunction with the cable restraint device of FIG. 1 .
[0006] FIG. 3A is a top view of multiple cable restraint devices installed on a base plate.
[0007] FIG. 3B is a side view of the embodiment of FIG. 3A .
[0008] FIG. 4 is an enlarged perspective view of the base piece of the cable restraint device of FIG. 1 .
[0009] FIG. 5 is a perspective view of the flexible pad of the cable restraint device of FIG. 1 .
[0010] FIG. 6 is a perspective view of the top piece of the cable restraint device of FIG. 1 .
[0011] FIGS. 7A and 7B illustrate an example cable restraint device attached to a device base integrated into a substrate.
[0012] FIGS. 8A and 8B illustrate an example cable restraint device having a single top portion.
[0013] FIGS. 9A and 9B illustrate an example cable restraint device and device base mounted in a housing.
DETAILED DESCRIPTION
[0014] The high frequency cable restraint device 100 , shown in FIG. 1 , comprises a base portion 102 , a top portion 104 and a flexible insert 106 . The device 100 is mounted on a device base 200 shown in FIG. 2 . The device base 200 features one or more mounting posts 202 , to mount the device 100 to the device base 200 . The one or more mounting posts 202 are secured to the base plate 204 . The base portion 102 of the device 100 fits over the mounting post 202 and the top portion 104 mounts to the mounting post 202 , restraining the cable restraint device 100 to the device base 200 .
[0015] The mounting posts 202 may be a stud featuring a flared end 203 that engages with and retains the restraint device 100 . Disposed in a pattern, multiple mounting posts positioned along the base plate 204 lay out a trace for the cables to follow. The pre-laid trace pattern assists in ensuring that the curve radii are sufficient to prevent damage to the cable while routed it is over a substrate, such as being routed through the housing of test equipment.
[0016] In the embodiment of the device base 200 shown in FIG. 2 , the base plate 204 and the mounting posts 202 are preferably made of metal. The mounting posts 202 are individual components that are affixed to the base plate 204 to form the device base 200 . In the example shown, the mounting posts 202 are riveted to the base plate 204 . Alternatively, the mounting posts 202 can be affixed to the base plate 204 using other fasteners, such as nut and bolt, adhesive, welding or soldering. The device base 200 , including the mounting posts 202 and the base plate 204 , can be formed as a single unit by casting, machining or other methods.
[0017] Both the base plate 204 and mounting post 202 may be made of any other suitable materials. Such materials include plastics, composites or ceramics. The use of other materials can be considered when taking into consideration the environment in which the cables will be placed. Insulative materials, such as plastic, can be used to electrically isolate the cables. Additional considerations such as cost and manufacturability can also be considered when selecting the material.
[0018] Locating holes 206 are disposed near the mounting posts 202 positions on the base plate 204 . The locating holes 206 receive and engage the protrusions 308 on the base portions 102 , as seen in FIG. 4 and discussed in more detail below. The engagement of the protrusions 308 and locating holes 206 assist in maintaining the orientation of the restraint devices 100 along the length of the device base 200 .
[0019] The base plate 204 further features holes 208 disposed along its length through which the device base 200 may be mounted to supports or a substrate 210 , as shown in FIGS. 3A and 3B . Alternatively, the device base 200 may be affixed in place using an adhesive or any other suitable attachment means.
[0020] The base portion 102 of the device 100 , as shown in FIG. 4 , is preferably constructed of plastic using an injection moulding process. Alternatively, the base 102 can be made of other suitable materials, such as a ceramic, metallic, rubber or other plastic material.
[0021] A central mounting column 304 , having a central mounting hole 306 , is disposed approximately in the center of the base portion 102 . The mounting column 304 receives and slides over the mounting post 202 through the mounting hole 306 . The mounting column 304 is structured to engage with a flared portion 203 of the mounting post 202 . The flared portion lightly restrains the base 102 to the device base 200 . Alternatively, the mounting column 304 may have a friction fit with the mounting post 202 to restrain the base 102 . In another embodiment, the mounting column 304 may slide loosely over the mounting post 202 and not actively engage with the one or more mounting posts 202 . In a further embodiment, the mounting column 304 can feature internal fins that engage with the mounting post 202 . These fins can be deformed, elastically or plastically, such that they exert a pressure on the mounting post 202 , restraining the base 102 to the mounting post 202 .
[0022] In an alternative embodiment, the base 102 may be retained in a position by an adhesive. The adhesive, such as glue, can be placed in the location, with the base 102 then being affixed. Alternatively, the base 102 may have an adhesive layer disposed on the underside of the bottom portion 204 . A protective sheet covers the adhesive and when removed the adhesive is exposed and the base 102 can be pressed into the desired position.
[0023] In a further embodiment, the base 102 may be mounted using a screw or nail. The screw or nail may be driven through the mounting column 304 into a substrate, such as the device base 200 or directly into a housing. The screw or nail can affix the base 102 only or can be driven through the top portion 104 , as well, thus securing the entire restraint device 100 to the desired position.
[0024] The high frequency cables run through the base 102 in channels 310 and 312 . These channels provide guides for the cables as they are run through the base 102 . The channels 310 and 312 do not exert any force on the cables and do not engage the cables to restrain them. This prevents undue pressure being exerted on the cables, which can damage them.
[0025] The channels 310 and 312 may be lined with cushioning material, such as a rubber or foam, to further protect the cables. The addition of such protection can also help isolate the cables from vibrations which can wear the cables should they rub against the base 102 .
[0026] Alternatively, the base 102 can feature a flat base, lacking the mounting column 304 and the channels 310 and 312 , but featuring the mounting hole 306 . The base 102 slides over the mounting post 202 through the mounting hole 306 . An insert can then be slid over the mounting post 202 . The insert can feature a mounting column to space the base 102 and the top portion 104 and a central portion that creates channels by dividing the base 102 .
[0027] The base 102 features a protrusion 308 located on a bottom surface. The protrusion 308 engages with a hole 206 in the base plate 204 of the device base 200 , as mentioned above. The hole 206 locates and orients the base 102 on the device base 200 . With the protrusion 308 engaged with the hole 206 , the base 102 is prevented from rotating about the mounting post 202 .
[0028] In an embodiment, ridges or protrusions formed on the upper portion of the sidewalls of the base 102 engage with the top portion 104 . When the top portion 104 is pressed into the base 102 , the two pieces engage and lock together forming the restraint device 100 .
[0029] A flexible insert 106 , as shown in FIG. 5 , is disposed atop the cables running through the base 102 . The flexible insert 106 is sized to fit within the base 102 and features a slit 402 that allows the pad to slide over and around the mounting column 304 . The flexible insert 106 is space-filling between the cables, base 102 and top portion 104 . While the flexible insert 106 is compressed by the top portion 104 , the pressure exerted on the wires through the flexible insert 106 is minimal and below the damage threshold. The slight pressure exerted by the flexible insert 106 on the wires prevents them from slipping or sliding through the restraint device 100 . In preventing this, undue damage to the cable wrapping and/or the cable itself can be prevented. Additionally, the slight pressure assists in ensuring that a steady or constant tension can be maintained on the cables as desired or necessary to ensure proper cable performance.
[0030] The flexible insert 106 may be composed of a number of suitable materials, such as rubber, latex, high and low density foam, or any other polymer. The flexible insert 106 material is selected to evenly distribute and minimize the force exerted on the cables from the closure of the top portion 104 to the base 102 .
[0031] The flexible insert 106 may be sculpted to further contour to the cables. Contouring the flexible insert 106 lessens the amount of pressure exerted on the cables and further distribute the exerted force evenly.
[0032] FIG. 6 illustrates an embodiment of the top portion 104 of the device 100 . The top portion 104 covers the base 102 , the flexible insert 106 and features a central hole 502 . When locked to the base 102 , by the mounting column 202 engagement with the central hole 502 , the top portion 104 lightly compresses the flexible insert 106 , exerting a pressure on the cables. The pressure is low enough to not damage the cables but is sufficient to slightly restrain the cables from sliding through the restraint device 100 .
[0033] To retain the top portion 104 to the base 102 , the mounting column 202 of the device base 200 has a flared end 203 that engages the central hole 502 of the top portion 104 . The engagement between the central hole 502 and the mounting column 202 is a friction fit sufficient to lock the top portion 104 to the mounting column 202 . The friction fit can be overcome by a user so that access can be gained to the cables running internal through the restrain device 100 . Additionally, a “click” type friction fit allows the device 100 to be opened and closed repeatedly and reused if so desired.
[0034] In an alternate embodiment, as discussed above, a screw or other fastener can be used to affix the device 100 . The fastener is driven through the central hole 502 of the top portion 104 , through the central column 304 of the base 102 and into a substrate to affix the device in a desired location. Alternatively, the base 102 can be affixed in a position using an attachment means, with the top portion 104 attached to the base 102 by a fastener.
[0035] In another embodiment, the flexible insert 106 may be integrated with the top portion 104 . This eliminates placing the flexible insert 106 in the device 100 before placing the top portion 104 .
[0036] Further means of attaching the top portion 104 on the base 102 may include using an adhesive. The top portion 104 may be glued or sealed onto the base 102 to prevent access to the cables, which may be desirable in some situations. The top portion 104 may also be taped to the base 102 . Laying tape across the top portion 104 additionally provides a tamper indication whereby a person attempting to access the cables within the restraint device 100 would have to break the tape seal. The broken tape provides an indication to service technicians or users that a person may have interacted with the restrained cables, thereby potentially damaging them. In an alternative embodiment of the restraint device, the entire device may be integrated with the substrate, as shown in FIGS. 7A and 7B . A channel 600 through which the cables are routed is disposed on or within the substrate 610 . The channel features mounting posts 602 disposed along the length. Top pieces 606 engage with the mounting posts 602 , as in the previous embodiments, to restrain the cables within the channel 600 . A flexible insert 604 is disposed between the cables and each of the top pieces.
[0037] Alternatively, a single top piece may be disposed across the whole length of the channel. The full-length top piece also has a flexible insert disposed between it and the cables to restrain them. An entire cable restraint device 700 can also be disposed across the device base 702 , as shown in FIGS. 8A and 8B .
[0038] FIGS. 9A and 9B show the cable restraint device 100 and the device base 200 mounted within a housing 800 .
[0039] To use the cable restraint device 100 , the base 102 is first placed over the mounting post 202 disposed on a base plate 204 of the device base 200 . The protrusion 308 of the base 102 engages the locating hole 206 on the base plate 204 . The engagement of the locating hole 206 and protrusion 308 combined with the engagement between the mounting post 202 and mounting column 304 moderately restrain the base 102 to the device base 200 . The cables are placed in the channels, 310 and 312 , and then the flexible insert 106 is placed over them. With the flexible insert 106 in place, the top portion 104 is secured to the mounting post 202 thereby completing the restraint device 100 and locking the device 100 firmly to the device base 200 .
[0040] Having described and illustrated the principles of the disclosed technology in a preferred embodiment thereof, it should be apparent that the disclosed technology can be modified in arrangement and detail without departing from such principles. We claim all modifications and variations coming within the spirit and scope of the following claims.
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A cable restraint system including a device base. The device base includes a base plate, and at least one mounting post disposed thereon, and a cable restraint device. The cable restraint device includes a base portion having at least one mounting column structured to receive the at least one mounting post, a pair of opposed sidewalls defining a trough structured to receive at least one cable, a flexible insert received in the base portion and disposed between the sidewalls, and a top portion spanning the sidewalls to retain the flexible insert within the base portion and structured to engage the at least one mounting post.
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BACKGROUND OF THE INVENTION
The present invention relates to new compounds useful as amphoteric surface active agents, a process for producing same and the use of the compounds. More particularly, the present invention relates to new disubstituted aliphatic carboxylamidoamines of the general formula: ##STR2## wherein R stands for an aliphatic hydrocarbyl group with 7-7 carbon atoms and M for a hydrogen atom or an alkali metal atom, a process for the production of same and detergents and toiletry composition containing the compounds of the general formula (I) as active ingredients.
Hitherto, compounds of the general formula: ##STR3## wherein R' stands for a long chain aliphatic hydrocarbyl group and M' for a hydrogen atom or an alkali metal atom, which are obtained by reacting a straight chain aliphatic carboxylic acid ester with aminoethylethanolamine were known as amphoteric surface active agents of substituted amidoamine type (U.S. Pat. Nos. 3,262,951 and 3,941,817).
Such amphoteric surface active agents are employed as detergents, fiber-treating agents, anti-static agents, toiletry bases and the like. In the case of using surface active agents as bases for shampoo, rinse, liquid facial soap and the like toiletries, such surface active agents are required to have no or little irritating property to skin, eyes and mucous membranes. However, the amphoteric surface active agents of substituted amido-amine type represented by the general formula (II) are not satisfactory in this respect and are thus unsuited for the purpose of bases for toiletries.
As a result of extensive researches made for developing amphoteric surface active agents which are less irritative to skin, eyes and mucous memburanes and thus suitable as bases for toiletries, it has now been found that new compounds of the above general formula (I) are suitable for this purpose and that the new compounds of the general formula (I) can be prepared efficiently by saponifying a reaction product of a 1-hydroxyethyl-2-substituted imidazoline, an alkyl acrylate and water with an alkali hydroxide. The present invention has been accomplished on the basis of the above findings.
BRIEF SUMMARY OF THE INVENTION
In accordance with the present invention, therefore, there are provided new disubstituted aliphatic carboxylamidoamines of the general formula (I), a process for the production of the compounds of the general formula (I) characterized by reacting imidazoline derivatives of the general formula: ##STR4## wherein R has the same meaning as given above, with an alkyl acrylate and water and thereafter saponifying the reaction product with an alkali hydroxide, and detergents and toiletry compositions containing the compounds of the general formula (I) as active ingredients.
Accordingly, it is an object of the present invention to provide new surface active agents which are less irritative to skin, eyes and mucous membranes.
It is another object of the present invention to provide a process for the production of the new surface active agents.
It is still another object of the present invention to provide detergents which are less irritative to skin, eyes and mucous membranes.
It is further object of the present invention to provide toiletries which are less irritative to skin, eyes and mucous membranes.
Other objects, features and advantages of the present invention will be apparent from the following description taken in connection with the accompanying drawings wherein:
FIG. 1 is an NMR-absorption spectrograph of the compound of this invention.
FIGS. 2 and 3 are IR-absorption spectrographs of the compounds of this invention.
FIGS. 4 and 5 are graphs showing the relation between the molar ratio of the starting material and the quantity of impurities in the product in the process of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Illustrative of the compounds of the present invention represented by the general formula (I) are N-(2-hydroxyethyl)-N-[di-(2-carboxyethyl) aminoethyl] octanoylamide, N-(2-hydroxyethyl)-N-[di-(2-carboxyethyl) aminoethyl] decanoylamide, N-(2-hydroxyethyl)-N-[di-(2-carboxyethyl) aminoethyl] undecanoylamide, N-(2-hydroxyethyl)-N-[di-(2-carboxyethyl) aminoethyl] dodecanoylamide, N-(2-hydroxyethyl)-N-[di-(2-carboxyethyl) aminoethyl] stearoylamide, N-(2-hydroxyethyl)-N-[di-(2-carboxyethyl) aminoethyl] lauroylamide, N-(2-hydroxyethyl)-N-[di-(2-carboxyethyl) aminoethyl] coconut oil fatty acid amides and sodium and potassium salts thereof.
According to the present invention, the compounds of the above general formula (I) can be prepared by reacting an imidazoline derivative of the general formula: ##STR5## wherein R has the same meaning as given above, with an alkyl acrylate and water and thereafter saponifying the reaction product with an alkali hydroxide.
Examples of the imidazoline derivative of the above general formula (III) include 1-(2-hydroxyethyl)-imidazolines substituted in 2-position thereof by an alkyl group such as octyl, nonyl, decyl, undecyl, dodecyl, pentadecyl, hexadecyl or heptadecyl group or by an alkenyl group such as octenyl, decenyl or pentadecenyl group.
Preferable examples of the alkyl acrylate to be reacted with the imidazoline derivative include methyl acrylate, ethyl acrylate and the like lower alkyl acrylates. This alkyl acrylate is used in an amount of 1.3-2.0 mols per mole of the imidazoline derivative. If the amount of the alkyl acrylate exceeds 2.0 mols, a large amount of unreacted acrylic acid as alkali salt will be present in the product. On the other hand, if the amount is less than 1.3 mols, the amount of unreacted amine will become larger, thus resulting in reduction in the yield of the product.
The amount of water supplied together with the alkyl acrylate to the reaction system is at least 1 mol, preferably within the range of 2.0-3.0 per mole of the imidazoline derivative. If the amount of water is less than 1 mol, the amount of unreacted amine will be increased, thus resulting in reduction in the yield of the product.
The reaction of the imidazoline derivative with the alkyl acrylate and water is carried out at a temperature within the range from room temperature to 100° C., preferably within the range of 60°-80° C. The time required for the reaction is usually within the range from 30 minutes to 4 hours. In the majority of cases, a conversion rate as high as about 99% can be obtained by the reaction carried out for 60 minutes. The reaction may be conducted, if desired, in the presence of an alkaline catalyst but the use of such alkaline catalyst is not especially necessary.
The addition product thus obtained is subjected, without being isolated, to the subsequent saponification treatment with an alkali hydroxide. This saponification treatment is carried out by adding to the reaction product an alkali hydroxide in an almost equimolar amount to the alkyl acrylate and heating the mixture at 50°-100° C. The time required for such saponification is usually about 2 hours at 70° C.
The reaction product thus obtained is distilled under reduced pressure to remove low molecular components contained therein whereby the end product or a reaction product composed predominantly of the end product is retained as a white solid. The end product obtained in this manner as white solid is subjected to a thin layer chromatography whereby a spot is detected to confirm that the product is pure. Results of IR-absorption spectral analysis, NMR-absorption spectral analysis and elementary analysis show that the end product has the structure of the above general formula (1).
The compounds of the present invention are characterized by their extremely low irritating property to skin, eyes and mucous membranes, as compared with the prior art surface active agents of a similar structure.
The compounds of the present invention are useful as detergent, fiber-treating agent, antistatic agent and the like, especially as bases for toiletries, for example, shampoo, hair rinse and liquid facial soap. In the case of using the compounds of the present invention for manufacturing toiletries, the compounds are incorporated with various conventional additives and other optional surface active agents to a desired toiletry composition.
The proportion of the compound of the present invention in such compositions is determined according to the intended use of the composition. Usually, however, the compound of the present invention is added in amount of 0.1-30% by weight based on the composition. In particular, the compound is used preferably in an amount of 0.5-25% by weight in the case of manufacturing detergents and preferably in an amount of 1-20% by weight in the case of manufacturing toiletry compositions.
To further illustrate this invention and not by way of limitation, the following examples are given.
EXAMPLE 1
In a 2 liter 4-necked flask equipped with a stirrer, a condenser and a thermometer were placed 268 g (1.0 mol) of 1-hydroxyethyl-2-undecylimidazoline and 200 g (2.0 mols) of ethyl acrylate. The mixture was stirred for 30 minutes at 25°-35° C. and 36 g (2.0 mols) of water was added thereto whereby the temperature was elevated up to 70° C. The mixture was reacted at this temperature for 2 hours and, after addition of 400 ml of ethyl alcohol and 80 g (2.0 mols) of sodium hydroxide, the mixture was reacted continuously at 70° C. for 3 hours to effect saponification. After completion of the reaction, the reaction mixture was distilled under reduced pressure to remove the ethyl alcohol whereby 473 g of disodium salt of N-(2-hydroxyethyl)-N-[di-(2-carboxyethyl) aminoethyl] lauroylamide was obtained. As a result of a thin layer chromatography where the product showed one spot, it was confirmed that this product was a single substance. As a result of an analysis for determination of carbon and hydrogen, the contents of carbon and hydrogen in this product were 55.62% (55.67% in calc. value) and 8.39% (8.50% in calc. value), respectively. The nitrogen content of this compound was determined as 5.78% (5.90% in calc. value) in a nitrogen analysis according to Kjeldahl method.
An NMR-absorption spectrum (60 MHz, D 2 O) and an IR-absorption spectrum (Nujol method) of this compound are shown in FIGS. 1 and 2, respectively. An IR-absorption spectrum of a product obtained by neutralizing this compound with hydrochloric acid is also shown in FIG. 3.
EXAMPLE 2
In the same flask as described in Example 1 were placed 268 g (1.0 mol) of 1-hydroxyethyl-2-alkylimidazoline manufactured from coconut oil fatty acids (average molecular weight: 200; AV 280) and 200 g (2.0 mols) of ethyl acrylate. The mixture was stirred for 30 minutes at 25°-30° C. and 36 g (2.0 mols) of water was then added thereto whereby the temperature of the mixture was elevated up to 70° C. The mixture was reacted for 2 hours at this temperature and 539 g of water was then added thereto. Further, 160 g (2.0 mols) of a 50% aqueous solution of sodium hydroxide was added and the mixture was heated at 70° C. for 2 hours to effect saponification. The reaction mixture was then distilled under reduced pressure to obtain 39.4% of an evaporation residue. In this manner, disodium salt of N-(2-hydroxyethyl)-N-[di-(2-carboxyethyl) aminoethyl] coconut oil fatty acid amide was obtained, which showed a pH value of 12.6. This product contained 0.2% by weight of unreacted amine and 0.1% by weight of sodium acrylate.
EXAMPLE 3
Except that the amount of ethyl acrylate was 150 g (1.5 mols), the amount of water added during the saponification reaction was 494 g and the amount of a 50% aqueous solution of sodium hydroxide was 120 g (1.5 mols), the experiment of Example 2 was repeated under the same conditions whereby a reaction product showing a pH value of 12.9 was obtained as 40% by weight of an evaporation residue. This product was a mixture of 60% by weight of disodium salt of N-(2-hydroxyethyl)-N-[di-(2-carboxyethyl) aminoethyl] coconut oil fatty acid amide and 40% by weight of sodium salt of N-(2-hydroxyethyl)-N-(2-carboxyethylaminoethyl) coconut oil fatty acid amide and contained 0.3% by weight of each of unreacted amine and sodium acrylate.
EXAMPLE 4
Except that 352 g (1.0 mol) of 1-hydroxyethyl-2-heptadecylimidazoline was used as the starting imidazoline derivative, the treatments were carried out in the same manner as described in Example 2 whereby an aqueous solution of disodium salt of N-(2-hydroxyethyl)-N-[di-(2-carboxyethyl) aminoethyl] stearylamide was obtained. This solution showed a pH value of 12.5 and gave 43.3% by weight of an evaporation residue which contained as impurities 0.2% by weight of unreacted amine and 0.1% by weight of sodium acrylate.
EXAMPLE 5
Except that 268 g (1.0 mol) of 1-hydroxyethyl-2-undecylimidazoline and 172 g (2.0 mols) of methyl acrylate were used, the experiment of Example 2 was repeated under the same conditions whereby disodium salt of N-(2-hydroxyethyl)-N-[di-(2-carboxyethyl) aminoethyl] undecanecarboxylamide was obtained. This product showed a pH value of 12.5 and the evaporation residue was 40.3% by weight which contained 0.2% by weight of unreacted amine and 0.1% by weight of sodium acrylate.
REFERENTIAL EXAMPLE 1
In accordance with the procedure disclosed in U.S. Pat. No. 3,941,817, 214 g (1.0 mol) of coconut oil fatty acid methyl ester obtained from a coconut oil fatty acid having an average molecular weight of 200, 107 g (1.03 mols) of aminoethylethanolamine and a 25% sodium methoxide solution in methyl alcohol were placed in a 1 l 4-necked flask equipped with a stirrer, a thermometer, a nitrogen gas inlet and a condenser connected to a vacuum pump. The mixture was gradually heated under a reduced pressure of 150 mmHg while introducing nitrogen thereinto. At a temperature of 100°-150° C., 31 g of the methyl alcohol was recovered whereby 286 g of N-coconut oil acrylated-N-hydroxyethylethylenediamine as obtained as residue.
The nitrogen inlet was then replaced by a dropping funnel and 375 g of water and 94.5 g (1.0 mol) of monochloroacetic acid were successively added and the mixture was cooled to 45° C. To this mixture was added carefully over a period of 10 minutes 160 g (2.0 mols) of an aqueous solution of 50% by weight of sodium hydroxide lest the external temperature should exceed 55° C. After addition of the solution, the mixture was reacted for 3 hours at 50°-60° C. and then for 2 hours at 80°-90° C. Sodium salt of N-(2-hydroxyethyl)-N-(2-carboxymethyl) aminoethyl coconut oil fatty acid amide was thus obtained.
REFERENTIAL EXAMPLE 2
The compound (Sample A) obtained in Example 1, the compound (Sample B) obtained in Example 3 and the compound (Sample C) obtained in Referential Example 1 were respectively dissolved in water to prepare a 8 wt% aqueous solution of each sample. A group consisting of three white male rabbits was treated with 0.1 ml of the aqueous solution and an eye-irritation test was performed according to Draize method. A result of the test is shown in Table 1.
Table 1__________________________________________________________________________ Total Hyperaemia 24Observation Cornea of Iris Conjunctiva ∫time (hr) 24 48 72 168 24 48 72 168 24 48 72 168 24 48 72 168 168__________________________________________________________________________Sample A 0 0 0 0 0 0 0 0 5 3 2 1 5 3 2 1 11Sample B 2 2 0 0 0 0 0 0 8 4 1 0 10 6 1 0 17Sample C 13 15 18 13 3 3 5 2 11 9 7 3 27 29 30 18 92__________________________________________________________________________
In the case of Sample A, i.e. the compound of the present invention, no trouble occurred in cornea and hyperaemia of iris was not found. Only a slight edema of conjunctiva was observed but it was not so serious. Thus, the compound of the present invention was found to be extremely low in eye-irritation.
EXAMPLE 6
Except that the molar ratio of ethyl acrylate to 1-hydroxyethyl-2-undecylimidazoline was varied, the reaction was carried out under the same conditions as described in Example 1 to prepare disodium salt of N-(2-hydroxyethyl)-N-[di-(2-carboxyethyl) aminoethyl] lauroylamide. FIG. 4 is a graph showing the relation between the molar ratio and the amount of acrylic acid (sodium acrylate) formed by hydrolysis of unreacted ethyl acrylate in the above reaction. FIG. 5 is a graph showing the relation between the molar ratio and the amount of a secondary amine formed as by-product.
As is evident from these graphs, the molar ratio of an alkyl acrylate to the imidazoline derivative is preferably within the range from 1.3 to 2.0.
The following examples illustrate detergents and toiletry compositions in which the compounds of the present invention are used.
EXAMPLE 7
Using disodium salt of N-(2-hydroxyethyl)-N-[di-(2-carboxyethyl) aminoethyl] coconut oil fatty acid amide as a typical compound of the present invention, a low irritative shampoo was manufactured according to the following recipe:
______________________________________Ingredients % by weight______________________________________The compound of the present invention 15Coconut oil fatty acid diethanolamide 3Citric acid monohydrate 2Ethyl p-hydroxybenzoate 0,5Preservative, perfume and colorant Adequate amountDeionized water Balance______________________________________
EXAMPLE 8
Using the same compound as described in Example 7, a hair rinse of emulsion type was prepared according to the following recipe:
______________________________________Ingredients % by weight______________________________________The compound of the present invention 2Distearyldimethylammonium chloride 3Ethyleneglycol monostearate 1Polyoxyethyleneoleyl alcohol 1Glycerol 5Perfume and colorant Adequate amountDeionized water Balance______________________________________
This hair rinse was substantially less irritative to eyes and was effective for facilitating the use of a comb for rinsed hair.
EXAMPLE 9
Using the same compound as described in Example 7, a liquid facial soap was manufactured according to the following recipe:
______________________________________Ingredients % by weight______________________________________The compound of the present invention 18Lauroyldiethanolamide 5citric acid monohydrate 1Perfume and colorant Adequate amountDeionized water Balance______________________________________
This soap showed no irritation to eyes.
EXAMPLE 10
Using the same compound as described in Example 7, a liquid detergent for domestic use was manufactured according to the following recipe:
______________________________________Ingredients % by weight______________________________________The compound of the present invention 9Lauroyldiethanolamide 3Sodium lauryl ether sulfate 10Sodium chloride 1Citric acid monochloride 1Perfume and colorant Adequate amountDeionized water Balance______________________________________
This detergent was equivalent in detergency to the prior art one but was superior in low irritation to the prior art oen.
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Disubstituted aliphatic carboxylamidoamines of the general formula: ##STR1## wherein R stands for an aliphatic hydrocarbyl group with 7-17 carbon atoms and M for a hydrogen atom or an alkali metal atom. Detergents and toiletry compositions incorporated with the disubstituted aliphatic carboxylamidoamines are extremely low in irritating property to skin, eyes and mucous membranes.
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This application is a division, of application Ser. No. 050,402, filed 5/18/87 now abandoned.
This invention relates to the utilization of differential gearing for controlling power transmission in accordance with functions or conditions desired by the operator and, in particular, to a differential-gearing arrangement in which the pinion gears are controlled in a manner to achieve the desired transmission of rotating motion from input to output.
The construction and operation of differentials in vehicle drive trains are well known. In a simple differential two driven ground wheels or tracks are permitted to turn at different speeds in response to unequal loads such as would occur, for example, when the vehicle deviates from a straight course. Independent rotation of the two wheel axles is achieved by the utilization in the differential assembly of freely rotatable pinion gears in mesh with side gears on the wheel axles, the shafts of the pinion gears being mounted in a rotating differential case or carrier which is driven by the propeller shaft that extends, typically, from the transmission. When the output loads are matched, the differential pinion gears are stationary on their axes but rotate with the carrier to drive the two output axles at equal speeds. As the vehicle traverses a turn, the pinion gears spin on their shafts thereby transmitting more rotary motion to one axle than to the other.
In the foregoing example of a simple differential, the pinion gears permit a speed difference in response to the effect of an external load or condition on the traction wheels, such as when a vehicle turns or encounters an inconsistent road surface. In contrast to this conventional usage of the differential principle as a means of responding to load imbalances, in the present invention the pinion gears are advantageously controlled to induce a speed difference, lock the output axles to the input shaft as desired to force the output axles to turn at the same speed, control the coupling and uncoupling of input and output shafts, and provide a controllable speed difference between input and output shafts.
It is, therefore, the primary object of the present invention to provide a differential-gearing device in which the rotation of the differential pinion gears is controlled in order to effect a desired relationship between the rotatably driven input shaft and the output shaft or shafts of the device.
A specific object of the present invention is to provide a device as aforesaid in which the pinion gears are driven in either direction of rotation by motor means on the carrier or differential case, controlled by a power source which does not rotate with the carrier and which enables the operator to control the speed and direction of drive of the pinion gears to induce a corresponding speed difference in the output shafts of the device.
Another specific object of the invention is to provide, in a second embodiment of the aforesaid device, a locking and limited slip differential in which fluid pump units on the carrier have operating shafts to which the respective pinion gears are fixed, and wherein by control of a fluid source for the pump units the lock, limited slip and conventional differential operational modes are achieved.
Still another specific object of the present invention is to provide, in a third embodiment thereof, a clutch apparatus by which input and output shafts may be selectively intercoupled and uncoupled through the use of fluid pump units on the carrier driven by the pinion gears and externally controlled to either permit free rotation of the pinion gears or lock the same against rotation to respectively isolate the input from the output or cause rotating motion to be transmitted to the output shaft.
A further specific object of this invention is to provide, in a fourth embodiment thereof, a variable speed transmission in which the pinion gears of the differential apparatus are controlled by pump units on the carrier and variable displacement fluid motor means on the output shaft of the apparatus in order to impart a desired speed difference between the input and output shafts.
Other objects of this invention will become apparent as the detailed specification proceeds.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified, diagrammatic, cross-sectional view of a differential device of the present invention employing hydraulic motors on the carrier to control the speed and direction of drive of the pinion gears to, in turn, induce a corresponding speed difference in the output shafts.
FIG. 2 is a view similar to FIG. 1 but showing a second embodiment of the present invention in which the controlled pinions provide a locking and limited slip differential through the use of hydraulic pump units on the carrier connected with the pinion gears.
FIG. 3 is a view similar to FIG. 1 but showing a third embodiment of the present invention in which the aligned shafts coaxial with the carrier provide the input to and the output from the device, the arrangement in this embodiment providing a hydraulic clutch for controlling the transmission of rotating motion from the input shaft to the output shaft.
FIG. 4 is a view similar to FIG. 3 but showing a fourth embodiment of the present invention in which the differential device provides a variable speed transmission.
DETAILED DESCRIPTION
Referring to FIG. 1, a housing 10 contains a differential case or carrier 12 supported therein on bearings 14 and 16 carried by opposed, internally projecting, hollow boss portions 18 and 20 respectively of the housing 10. The carrier 12 is rotatable about an axis that is coaxial with respect to left and right output shafts or axles 22 and 24 which extend from housing 10 and are journaled in bearings 26 in the wall of the housing and bearings 28 in the carrier 12. The inner ends of the output shafts 22 and 24 are closely spaced from each other and terminate at a central chamber 30 within the carrier 12, and are provided with bevel side gears 32 and 34, respectively, in mesh with a pair of opposed, differential pinion gears 36 and 38.
An input shaft 40 forming, for example, part of the power train of a vehicle extends, typically, from the vehicle transmission and into the housing 10 through a bearing 42, the end of the input shaft 40 being provided with a drive pinion 44 in mesh with a ring gear 46 fixed to the carrier 12 and coaxial with the opposed output shafts 22 and 24. Accordingly, the components thus far described comprise a conventional bevel-gear differential for transmitting and distributing the rotating motion of the input shaft 40 to the two output shafts 22 and 24.
In the present invention, however, the pinion gear 36 is fixed to the end of the drive shaft 48 of a hydraulic motor 50 mounted in the wall of the carrier 12 and rotable therewith. As may be appreciated from viewing FIG. 1, the wall of the carrier 12 surrounding the chamber 30 is suitably bored or recessed to receive and retain the hydraulic motor 50. The fluid inlet and outlet 52, 54 of the hydraulic motor 50 are communicated by channels 56, 58 within the carrier body to corresponding ports 60, 62 on the circumferential periphery of a reduced, cylindrical end portion 64 of carrier 12 that is received within the boss 20 and supported by bearing 16. Three axially-spaced, annular seals 66 are sandwiched between the outer, circumferential surface of end portion 64 and the opposing inner surface of boss 20 and disposed, as seen in FIG. 1, between and on both sides of the ports 60 and 62. For example, O-rings seated in grooves (not shown) in the boss 20 may be employed as the seals 66. Accordingly, an annular space between adjacent seals 66 is formed at each port 60 and 62 to provide continuous fluid communication of these ports with an external fluid source during rotation of the carrier 12. Channels 68 and 70 in boss 20 extend from the annular spaces thus created to the outside of the housing 10 where hydraulic lines 72 and 74 communicate channels 68 and 70, respectively, with a hydraulic pump 76 and a reservoir 78 via a two-way valve 80. Although valve 80 is diagrammatically illustrated as a simple valve for reversing fluid flow in the lines 72 and 74, it should be understood that in practice the valve 80 would be provided with a variable orifice or other means of controlling fluid flow so that the volume of the fluid flow, as well as its direction, will be under the control of the operator.
Likewise, the pinion gear 38 is fixed to the shaft 82 of a hydraulic motor 84 having a fluid inlet and outlet 86, 88 communicated by respective channels 90, 92 in housing 12 with the corresponding annular spaces defined by the three seals 66. The pinion gears 36 and 38 can be driven in either direction, depending upon the direction of fluid flow as governed by the valve 80. In either operational condition, the opposing pinion gears 36 and 38 rotate in opposite directions. Accordingly, utilization of the differential of FIG. 1 in tracked vehicles provides direct control of the relative speeds of the two output axles for steering purposes without the need to employ a complex drive or to declutch and apply a brake to the track on the inside of a turn.
Referring to the embodiment of FIG. 2, the differential-gearing device there shown is structurally identical to the embodiment of FIG. 1 except for the substitution of hydraulic pump units 100 and 102 for the hydraulic motors 50 and 84 respectively, and a modification of the external hydraulic system. Accordingly, the same reference numerals are utilized in FIG. 2 to designate like parts and components, with the addition of the "a" notation. The embodiment of FIG. 2 provides a locking and limited slip differential for wheeled vehicles where, under adverse traction conditions, it is desired to have the capability of forcing the output shafts 22a and 24a to rotate at the same speed or limit the speed difference therebetween.
The hydraulic pump units 100 and 102 are positive displacement pumps in which control of fluid flow results in control of the pinion gear motion. Pump unit 100 has an oil inlet 104 and an outlet 106 communicating with external hydraulic lines 74a and 72a which extend to a reservoir 108 via a valve 110 under the control of the operator. The pinion gear 36a is fixed to the operating shaft 112 of pump unit 100; likewise, the pinion 38a is fixed to the operating shaft 114 of pump unit 102. The hydraulic lines 72a and 74a, via channels 68a, 70a and 90a, 92a, extend to the oil outlet 118 and inlet 116 of pump unit 102. When the valve 110 is in the open position illustrated, the pump shafts 112 and 114 (and hence the pinon gears 36a and 38a) are allowed to rotate freely as fluid flow to and from the reservoir 108 is unimpeded. In this mode, therefore, the speed of output shafts 22a and 24a is allowed to vary independently. However, upon closure of the valve 110, fluid flow in the hydraulic system is blocked and the hydraulic pumps 100 and 102 are locked to force the output shafts 22a and 24a to rotate at the same speed. It may be appreciated that partial opening of the valve 110 restricts the fluid flow from the pumps 100 and 102 and thus limits the speed variation between the two output shafts 22a and 24a.
It should be understood that any number of pinion gears may be employed in the differential assembly of FIG. 2 and in the other embodiments of FIGS. 1, 3 and 4. In light duty applications it may not be necessary to control all of the pinion gears, thus some may be left to rotate freely.
Referring to FIG. 3, this embodiment of the invention provides a hydraulic clutch for controlling the transmission of rotative motion from an input shaft 120 to an output shaft 122 coaxially aligned therewith. Other than right to left reversal and a modification in the interior configuration of the housing 10b, the differential-gearing arrangement and control of the pinion gears are identical to that shown in FIG. 2 except for the arrangement of the input and output shafts of the device. It may be seen that the drive pinion and ring gear are omitted and that the input is supplied by the shaft 120 which has its inner end fixed to the bevel side gear 32b. The opposing, inner end of the output shaft 122 carries the bevel side gear 34b. Other parts and components identical to that described or illustrated in FIG. 2 are identified by the same reference numerals with the addition of the "b" notation.
External hydraulic lines 124 and 126 communicate with a reservoir 128 via a valve 130, and extend to passages 132 and 134, respectively, in housing 10b that, in turn, communicate via the rotating fluid coupling with the oil inlets 104b, 116b and outlets 106b, 118b of the hydraulic pump units 100b and 102b. Each of the pump units 100b and 102b is a positive displacement piston pump driven by the corresponding pinion gear 36b or 38b. When the valve 130 is open as illustrated, fluid flows freely between the reservoir 128 and the pump units 100b and 102b; thus, the pinion gears 36b and 38b rotate in response to the input shaft 120 and rotation is not transmitted to the output shaft 122. Closure of the valve 130 blocks fluid flow and locks the pump units 100b and 102b to thereby prevent rotation of the pinion gears 36b and 38b and transmit rotating motion to the output shaft 122.
The embodiment of FIG. 4 employs the principles of the present invention to provide a variable speed transmission. The differential gearing arrangement is identical to that illustrated in FIG. 3, corresponding parts and components being identified by the same reference numerals with the addition of the "c" notation. The embodiment of FIG. 4 differs from FIG. 3 in that a variable displacement hydraulic motor 140 is mounted within the housing 10c but is separate from the rotatable carrier 12c. The output shaft of hydraulic motor 140 is connected by spur gears 142 to output shaft 122c, external hydraulic lines 144 and 146 being communicated with motor 140 via passageways 148 and 150 respectively in housing 10c. Hydraulic line 144 communicates with a reservoir 152, whereas line 146 communicates with passage 132c via a valve 154 and line 156. A hydraulic line 158 extends from passage 134c to the reservoir 152. The transmission is disengaged (drive removed from output shaft 122c) when the valve 154 is shifted to a position communicating line 156 with reservoir 152, thereby removing the hydraulic motor 140 from the hydraulic system and rendering the pinion gears 36c and 38c freely rotatable as in FIG. 3 (declutched condition).
OPERATION
The differential with axle speed control of FIG. 1 may be advantageously utilized to steer a tracked vehicle as previously discussed. When the input shaft 40 is in motion, the direction of fluid flow in the hydraulic lines 72 and 74, as governed by the position of the valve 80, determines which axle or output shaft 22 or 24 has the highest speed. The volume of fluid flow determines the speed difference between the two axles and, therefore, the rate at which the turn is executed.
When the input shaft 40 is stopped, as would occur with the drive disengaged, the output shafts 22 and 24 will turn in opposite directions as governed by the direction of fluid flow in the lines 72 and 74. Again, the volume of fluid flow will determine the speed difference between shafts 22 and 24. This enables a tracked vehicle to turn in place while stopped.
With respect to the locking and limited slip differential provided by the embodiment of FIG. 2, it may be seen that the substitution of hydraulic pumps 100 and 102 for the hydraulic motors 50 and 84 utilized in FIG. 1, and modification of the external hydraulic system, provide a means of locking the output shafts 22a and 24a under difficult traction conditions such as icy roadways. As the embodiment of FIG. 2 is primarily intended for wheeled vehicles, steering is accomplished in the conventional manner. It should be appreciated that in both the embodiments of FIGS. 1 and 2, as well as FIGS. 3 and 4, continuous hydraulic connections are effected to the rotating carrier through the utilization of the seals 66 that define annular spaces between the stationary and rotating parts of the device.
The hydraulic clutch of FIG. 3 is engaged by operating the valve 130 to block the fluid flow in the lines 124 and 126, thereby freezing the piston pumps 100b and 102b to prevent rotation of the pinions 36b and 38b. The output shaft 122 under such condition is forced to rotate with the input shaft 120 by virtue of the interengagement of the pinion gears and the side gears 32b and 34b. If valve 130 is partially closed rather than fully closed, restricted fluid flow to and from the reservoir 128 will permit a degree of rotation of the pinion gears 36b and 38b and thus drive the output shaft 122 but at a slower speed than the input shaft 120.
In the variable speed transmission of FIG. 4, both the valve 154 and the variable displacement hydraulic motor 140 are under the control of the operator. The hydraulic motor 140 may, for example, comprise a piston-type motor having a displacement that is varied by changing the length of the stroke of the pistons, and would typically be varied by a hand-control lever (not shown). The transmission of FIG. 4 operates much in the same manner as the clutch of FIG. 3 with the addition of the motor 140 which permits control of the speed of the output shaft 122c and increases efficiency when the output speed is less than the speed of the input shaft 120c.
The function of the variable displacement motor 140 is to control the volume of fluid flow in the hydraulic system that includes the two pump units 100c and 102c connected to the pinion gears 36c and 38c. At high displacement, which is high fluid flow, the output speed is lower than the input speed. When the displacement is reduced to zero, fluid flow stops, the pinion gears are locked and output speed equals input speed. Accordingly, by varying the displacement of the motor 140 between zero and maximum, the ratio of the speed of the output shaft 122c to the speed of the input shaft 120c is controlled and may be selected as operating conditions dictate.
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Differential-gearing devices are disclosed in which the differential pinion gears are controlled to induce a speed difference between output shafts, provide a locking and limited slip differential to equalize the speeds of the output shafts or limit their speed difference, provide a clutch for controlling the coupling and uncoupling of an input shaft to an output shaft, and provide a variable speed transmission. These operational modes are implemented by mounting hydraulic motor or pump units on the rotating carrier of the differential apparatus, the pinion gears being fixed to the shafts of the respective units. A controllable external fluid source independent of the carrier is in fluid communication with the units via conduits through the stationary housing of the differential device and the rotating carrier. Fluid flow may be either blocked, limited or unimpeded between the source and the units to effect the desired control of the pinion gears to, in turn, determine the operational mode of the apparatus.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a United States National Phase Application of International Application PCT/EP2014/068860 filed Sep. 4, 2014 and claims the benefit of priority under 35 U.S.C. §119 of German Patent Applications 10 2013 217 736.4 filed Sep. 5, 2013 and 10 2013 223 834.7 filed Nov. 21, 2013, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to a composite component for a vehicle seat, in particular for a motor vehicle seat, comprising a plurality of woven fabric layers consisting of a fibrous material, a matrix material securing the woven fabric layers, and an insert part, which is arranged between at least two of the woven fabric layers, for locally reinforcing the composite component. The invention also relates to a vehicle seat, in particular a motor vehicle seat.
BACKGROUND OF THE INVENTION
[0003] The prior art discloses components for vehicle seats made of fiber composite materials, said components being constructed from individual woven fabric layers, which consist of fibrous material, and from a matrix material surrounding the fibrous material, and therefore the woven fabric layers are embedded in the matrix material. These components are also referred to as composite components. The production can be carried out, for example, in the form of a manual laminate or by a non automated resin transfer molding process (RTM).
[0004] The connection of a composite component, which is highly loadable by external forces, to an adjacent structure, for example the connection of a carbon backrest of a vehicle seat to a backrest inclination adjustment fitting, necessitates the local reinforcement of the composite component with a high strength insert part which is arranged between individual woven fabric layers and is therefore fixedly integrated in the composite component. The insert parts used are in particular steel sheet metal parts. Under high loading of the composite component, an undesirable “knife effect” may occur, in which the insert part cuts up and therefore destroys the composite component internally. The knife effect occurs in particular in the plane of the insert part and in a region located outside the region reinforced by the insert part. This effect can be only slightly reduced by the edges of the insert part being machined, in particular rendered harmless, in a complicated manufacturing step.
SUMMARY OF THE INVENTION
[0005] The invention addresses the problem, in a composite component, which is reinforced with an insert part, for a vehicle seat, of avoiding, or at least significantly reducing, the previously described knife effect, which is caused by the insert part. The solution is also intended to make it possible for the composite component to be able to be produced by automated manufacturing, in particular in the RTM process. The composite component is intended to be suitable in particular for use in a vehicle seat and is intended to increase the strength and crash safety of a vehicle seat by the use of such a composite component.
[0006] This problem is solved according to the invention by a composite component for a vehicle seat, in particular for a motor vehicle seat, comprising a plurality of woven fabric layers consisting of a fibrous material, a matrix material securing the woven fabric layers, and an insert part, which is arranged between the woven fabric layers, for locally reinforcing the composite component, wherein an insert strand is arranged at least in sections along an edge or an edge surface of the insert part.
[0007] An insert part arranged between at least two of the woven fabric layers is preferably located between precisely two woven fabric layers, which are arranged next to each other, of a multiplicity of woven fabric layers. However, individual woven fabric layers may also overlap in the region of the insert part on one side of the insert part, and therefore the insert part can be arranged between a plurality of woven fabric layers. The number of woven fabric layers lying one above another on a side of the insert part in each case is not relevant to the invention and in this respect is not limited.
[0008] Owing to the fact that an insert strand is arranged at least in sections along an edge or an edge surface of the insert part, the edge or the edge surface is covered by the insert strand. As a result, direct contact between the sharp edge or edge surface and the adjacent woven fabric layers and the adjacent matrix material of the composite component can be avoided and therefore a knife effect within the composite component can also be avoided. Furthermore, a limited displacement of the insert part within the composite component can be compensated for without loading or destroying the bond of the composite component.
[0009] The insert part is advantageously formed flat, for example is cut out of a metal sheet. A flat insert part can easily be arranged between individual woven fabric layers of the composite component. In regions around the insert part, the woven fabric layers, between which the insert part is located, bear against one another and are secured with respect to one another by matrix material. A surface side of the insert part is preferably covered by a first layer of woven fabric layers and matrix material, and a further surface side of the insert part is covered by a second layer of woven fabric layers and matrix material.
[0010] The first layer and the second layer are connected to each other by means of matrix material in addition to the insert part.
[0011] The insert part can have an interface for the connection of the composite component to an adjacent component, for example a threaded bushing with an internal thread for the screwing on of an additional component. In order to ensure direct accessibility of the interface, it is of advantage if the insert part is not covered locally by woven fabric layers and matrix material, for example in the region of a thread.
[0012] The term insert strands should be understood as meaning elongate profiles, in particular with a constant cross section, as can be produced, for example, by extrusion. However, the invention can basically also be carried out with insert strands, the cross sections of which change along the strand profile.
[0013] The term edge surface should be understood as meaning in particular a surface defined in height by the sheet metal thickness of the insert part, while an edge is a line, in particular on an edge surface.
[0014] In a transition region between the insert part and a monolithic region consisting of woven fabric layers and matrix material, a cross sectionally triangular, in particular wedge shaped region without woven fabric layers is formed because of minimally permissible bending radii of the woven fabric layers. Said region is preferably substantially filled with the insert strand. However, the profile shape of the insert strand is not necessarily predetermined by the minimally permissible bending radii of the woven fabric layers, but rather can be selected freely and can be adapted to the load situations and the matrix and fibrous materials used.
[0015] The cross section of the insert strand is preferably approximately triangular or wedge shaped. The corners of the cross section of the insert strand are preferably rounded here. As a result, a continuous, gentle transition takes place between the monolithic composite component region and the sandwich construction (composite-insert-composite), said transition optimally controlling the force flux within the actual woven fabric layers.
[0016] The material of the insert strand preferably has a lower strength and/or a lower hardness in comparison to the woven fabric fibers. An insert strand consisting of glass fibers is advantageously inserted in a carbon component.
[0017] A particularly cost effective insert strand is designed as a rubber band or plastics band.
[0018] The insert part is preferably a punched part, in particular made of steel, which is produced cost effectively by means of a punching tool. A burr possibly arising during the punching does not have to be removed since said burr cannot damage the composite component internally because of the insert strand.
[0019] By the composite component being designed as a backrest structure for a vehicle seat or as a component of a backrest structure for a vehicle seat, and comprising an insert part for connecting the backrest structure to a fitting, it is possible to provide high strength backrest structures, via the connecting points of which to the fittings high forces and torques can be conducted. The fittings used are preferably latching fittings, as known, for example, from WO 2011/029522 A2, or geared fittings, as known, for example, from WO 2011/029520 A2.
[0020] The outer component contour of the composite component is formed at least in sections by a woven fabric strand embedded in the matrix material. A retrospective trimming of the component contour can thereby be dispensed with.
[0021] For the connection to the woven fabric layers, the woven fabric strand is embedded in the matrix material and is therefore at least partially surrounded by matrix material. The term embedded should be understood as meaning a complete or a partial encasing of the woven fabric strand woven fabric with matrix material or a complete penetration or partial penetration of the woven fabric with matrix material, and any combination thereof.
[0022] The woven fabric strand is preferably designed as a woven fabric tube or a braided tube. The braided tube differs from the woven fabric tube in that the fibers are not supplied at right angles during the braiding of the braided tube. Alternatively, the woven fabric strand is designed as a woven fabric band or a flexible cord, i.e. a substantially flat, in particular two dimensional braid. Woven fabric tubes and braided tubes or woven fabric bands and flexible cords which are known per se and are available cost effectively can be used as the woven fabric strand, which reduces the component costs. The term woven fabric strand should be understood as meaning a collective term for woven fabrics and braids which are formed in an elongate manner and are known per se, irrespective of angular positions of the fibers with respect to one another or absolutely.
[0023] The composite component comprises ready premanufactured woven fabric layers. During the production process, in particular the woven fabric layers and a braided tube are positioned in a mold, preferably by a robot. However, in the event of low piece numbers, the positioning may also take place manually.
[0024] The problem is also solved by a vehicle seat comprising a composite component according to the invention. A vehicle seat of this type provides high strength and high rigidity at a low weight.
[0025] The invention is explained in more detail below with reference to an advantageous exemplary embodiment which is illustrated in the figures. However, the invention is not restricted to this exemplary embodiment. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] In the drawings:
[0027] FIG. 1 is a perspective view of an un upholstered vehicle seat with a backrest according to the exemplary embodiment;
[0028] FIG. 2 is a side view of the un upholstered vehicle seat from FIG. 1 ;
[0029] FIG. 3 is a perspective view of the backrest from FIG. 1 ;
[0030] FIG. 4 is a side view of the backrest from FIG. 1 ;
[0031] FIG. 5 is a sectional view along the line V V in FIG. 3 ;
[0032] FIG. 6 is a perspective rear view of the backrest from FIG. 1 ;
[0033] FIG. 7 is a detailed view from FIG. 6 ; and
[0034] FIG. 8 is a sectional view along the line VIII VIII in FIG. 7 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] A vehicle seat 1 , designed in the present case as a sporty seat, for a motor vehicle has a backrest and a seat underframe. The backrest and the seat underframe are connected to each other by means of two fittings 10 which are known per se. For this purpose, each of the two fittings 10 has a fitting upper part 20 , which is connected to a backrest structure 110 , which is in the form of a composite component, of the backrest, and a fitting lower part 30 , which is connected to a seat underframe structure 210 of the seat underframe. The fitting upper part 20 and the fitting lower part 30 are adjustable relative to each other via a fitting mechanism which is known per se, for example a latching fitting or a geared fitting, and therefore the inclination of the backrest structure 110 about a backrest pivot axis A can be set.
[0036] The vehicle seat 1 , which is illustrated un upholstered in FIG. 1 , is described below using three spatial directions which are perpendicular to one another. With a vehicle seat 1 installed in the vehicle, a longitudinal direction x runs substantially horizontally and preferably parallel to a longitudinal direction of the vehicle, which corresponds to the customary direction of travel of the vehicle. A transverse direction y running perpendicularly to the longitudinal direction x is likewise oriented horizontally in the vehicle and runs parallel to a transverse direction of the vehicle. A vertical direction z runs perpendicularly to the longitudinal direction x and perpendicularly to the transverse direction y. With a vehicle seat 1 installed in the vehicle, the vertical direction z runs parallel to the vertical axis of the vehicle.
[0037] The position and direction details used, for example at the front, at the rear, at the top and at the bottom, relate to a viewing direction of an occupant sitting in the vehicle seat 1 in a normal seat position, wherein the vehicle seat 1 installed in the vehicle is oriented in a use position, which is suitable for conveying individuals, with an upright backrest and as customary in the direction of travel. However, the vehicle seat 1 according to the invention can also be installed in a differing orientation, for example transversally with respect to the direction of travel.
[0038] The backrest structure 110 is covered laterally and from the rear with a design shell 180 which is illustrated in half section in FIGS. 1 and 2 . In the case of an upholstered vehicle seat 1 , a foam part (not illustrated in the Figures) is arranged on the front side of the backrest structure 110 . The foam part is covered with a cover (likewise not illustrated in the Figures), the outer edge contours of which are fastened to the design shell 180 or alternatively to the backrest structure 110 such that the cover and the design shell 180 accommodate the backrest structure 110 and the foam part between each other. In a modification of the exemplary embodiment, the design shell 180 is omitted and the rear side of the backrest structure 110 forms the rearmost visible surface of the backrest.
[0039] The design shell 180 and the cover define the outer design of the backrest without substantially contributing to the strength of the backrest. In the present case, the design shell 180 is an injection molded part composed of a plastic which is known per se. The cover is preferably substantially composed of material and/or leather.
[0040] The backrest structure 110 is a load bearing structural part of the vehicle seat 1 . The forces, in particular crash forces, acting on the backrest are substantially absorbed by the backrest structure 110 and transmitted via the fittings 10 into the seat underframe structure 210 .
[0041] The backrest structure 110 is a composite component and has a shell construction composed of a composite material. In the present case, the backrest structure 110 comprises a bond composed of a resin, in particular an epoxy resin, as matrix material 118 and a multiplicity of carbon fibers reinforcing the matrix material 118 .
[0042] The carbon fibers are arranged in a plurality of woven fabric layers 116 , wherein each of the woven fabric layers 116 is a three dimensionally shaped fabric, in particular a multi axial fabric, in which the carbon fibers are arranged in different directions from one another and form a woven fabric. In a modification of the exemplary embodiment, the fibers are arranged unidirectionally or a laid scrim is used.
[0043] The woven fabric layers 116 are surrounded and penetrated by the matrix material 118 by the backrest structure 110 being produced, for example, by means of a resin transfer molding process (RTM) or another method known per se for producing carbon fiber reinforced plastic components.
[0044] Between individual woven fabric layers 116 , a core 130 or, alternatively, a plurality of cores 130 is or are arranged in sections over wide regions of the backrest structure 110 . FIG. 5 shows a section through the backrest structure 110 in a region having a core 130 . The core 130 is arranged between two approximately identically thick layers of in each case a plurality of woven fabric layers 116 surrounded by matrix material 118 . This results in a sandwich construction of the core 130 and the composite material composed of woven fabric layers 116 and matrix material 118 .
[0045] The core 130 consists of a rigid foam or, alternatively, of a soft foam, for example of PVC foam, and serves for energy absorption, for example in the event of an accident.
[0046] The outer encircling edge region of the backrest structure 110 is formed in sections by two flat, but three dimensionally shaped braided tubes 125 which are embedded in matrix material 118 and run along the outer contour of the backrest structure 110 . Flat in the present case means that each braided tube 125 has only a very small inner cavity, if any at all. Each of the two braided tubes 125 is pressed together from a tube having, for example, an originally round cross section such that—as can be seen in FIG. 5 —the cross section of each of the two braided tubes 125 has a tube section which, in the length thereof, corresponds approximately to half of the inner circumference of the cross section of the braided tube 125 and lies very closely opposite the remaining tube section or bears there against. The possibly present small cavity is filled in the present case and preferably with matrix material 118 .
[0047] Each of the two braided tubes 125 is composed of a carbon fiber woven fabric, in the present case with a +/−45° fiber orientation.
[0048] The cross section of the two flat braided tubes 125 is in each case approximately S shaped. The two braided tubes 125 are adjacent to each other and oriented in a substantially identical position to each other. In a first end region 125 . 1 of the cross section of the two braided tubes 125 , which end region is oriented in the direction of the center of the backrest structure 110 , the two braided tubes 125 accommodate the outer edges of the individual woven fabric layers 116 between each other. As a result, the tubes overlap the outer edges of the woven fabric layers 116 . The outer edges of the individual woven fabric layers 116 and the two braided tubes 125 are connected to each other in the first end region 125 . 1 by means of the matrix material 118 .
[0049] In a second end region 125 . 2 of the cross section of the two braided tubes 125 , which end region lies opposite the first end region 125 . 1 and defines the outer edge of the backrest structure 110 , the contours of the braided tubes 125 lie directly one inside the other and are surrounded and secured with respect to each other by matrix material 118 .
[0050] Tolerances in the trimming and in the orientation of the individual woven fabric layers 116 are compensated for by the described overlapping arrangement of the braided tubes 125 with respect to the outer edges of the individual woven fabric layers 116 such that the outer contour of the backrest structure 110 is untrimmed, but nevertheless has a smooth and continuous contour profile by means of the braided tubes 125 .
[0051] In a modification of the exemplary embodiment, just one braided tube 125 in sections forms the outer, encircling edge region of the backrest structure 110 . The woven fabric layers 116 overlap the tube in sections, but not as far as the outer contour of the backrest structure 110 .
[0052] In a further modification of the exemplary embodiment, a flat woven fabric band in sections forms the outer, encircling edge region of the backrest structure 110 . Two woven fabric bands which correspondingly accommodate the edges of the woven fabric layers 116 between each other are also conceivable.
[0053] The backrest structure 110 is substantially mirror symmetrical to a plane running parallel to the longitudinal direction x and parallel to the vertical direction z through the seat center.
[0054] The backrest structure 110 comprises, as seen in the transverse direction y, in the two outer regions a connecting surface 112 , which is of substantially flat design, for the connection in each case of one of the two fitting upper parts 20 . The two connecting surfaces 112 run perpendicularly to the backrest pivot axis A and therefore parallel to the longitudinal direction x and to the vertical direction z.
[0055] In the Figures, the two connecting surfaces 112 are illustrated in transparent form, and therefore an insert part 140 which is incorporated in the regions of the connecting surfaces 112 of the backrest structure 110 is visible in each case although said insert part, as is described in more detail below, is surrounded by woven fabric layers 116 and matrix material 118 . The fitting upper parts 20 which are partially concealed by the backrest structure 110 are also visible in the Figures because of the transparent manner of illustration.
[0056] The two insert parts 140 and the two connecting surfaces 112 are constructed symmetrically with respect to one another with respect to a mirror plane running in the longitudinal direction x and in the vertical direction z through the seat center, and therefore only one side of the backrest structure 110 is described below.
[0057] The insert part 140 is composed of steel sheet, in particular stainless steel sheet or a steel sheet with an anti-corrosion coating, and comprises a substantially flat plate 141 . Three threaded bushings 142 with an internal thread 143 are welded into the plate 141 . The center lines of the internal threads 143 are oriented in the transverse direction y. In the region of the internal threads 143 , the insert part 140 is not covered by woven fabric layers 116 or matrix material 118 .
[0058] A centering bore 146 serves for orienting the insert part 140 in a mold during the production of the backrest structure 110 , in particular also for orienting same with respect to the opposite insert part 140 , as seen in the transverse direction y. Alternatively to the centering bore 146 or additionally thereto, a threaded bushing for the screwing on of an additional component, for example an electric motor for driving the fittings 10 , can also be provided.
[0059] In addition, the plate 141 comprises a plurality of passages 148 , in the present case circular holes with a respective center axis parallel to the transverse direction y and with a diameter which is smaller than the diameter of the internal threads 143 . The passages 148 permit viscous matrix material 118 to pass therethrough during the production process of the backrest structure 110 .
[0060] FIG. 8 illustrates a section through the backrest structure 110 in the region of the insert part 140 . One of the two surface sides of the insert part 140 is covered by a first layer 116 . 1 of woven fabric layers 116 and matrix material 118 , the other surface side of the insert part 140 is covered by a second layer 116 . 2 of woven fabric layers 116 and matrix material 118 . At a small distance from an edge surface 141 . 1 of the plate 141 , the first layer 116 . 1 and the second layer 116 . 2 converge outside the region of the plate 141 and monolithically form there a uniform bond of woven fabric layers 116 and matrix material 118 .
[0061] In the transition region between the plate 141 and the monolithic region of woven fabric layers 116 and matrix material 118 , a cross sectionally triangular, in particular wedge shaped region which does not have woven fabric layers 116 and is filled with a triangular, in particular wedge shaped insert strand 150 , is formed because of minimally permissible bending radii of the woven fabric layers 116 . The insert strand 150 comprises a first side 150 . 1 , a second side 150 . 2 and a third side 150 . 3 . In the transition region between the plate 141 and the monolithic region, the first side 150 . 1 bears against the first layer 116 . 1 , and the second side 150 . 2 bears against the second layer 116 . 2 . A third side 150 . 3 of the insert strand 150 bears against the encircling edge surface 141 . 1 of the insert part 140 , which edge surface is defined by the sheet metal thickness of the plate 141 .
[0062] In the present case, the insert strand 150 is a glass fiber strand encircling the outer contour of the insert part 140 , and, by means of the wedge shape thereof, brings about a continuous, gentle transition between the monolithic component region and the sandwich construction consisting of the insert part 140 and the woven fabric layers 116 , which surround the insert part 140 , in particular on both sides, and the matrix material 118 .
[0063] In a modification of the exemplary embodiment, the insert strand 150 can also be configured as a rubber band.
[0064] In the present case, the second fitting upper part 20 is manufactured from steel sheet and has a flat basic body 22 which runs substantially parallel to the longitudinal direction x and to the vertical direction z and bears against the connecting surface 112 . Three through holes 23 are aligned with the three internal threads 143 of the insert part 140 , and therefore the fitting 10 can be screwed at these points to the backrest structure 110 . The three threaded bushings 142 end flush with the connecting surface 112 or project slightly over the latter, and therefore the basic body 22 of the fitting upper part 20 bears directly against the end surfaces of the threaded bushings 142 . This avoids damage to the matrix material 118 and/or to the woven fabric layers 116 .
[0065] In a modification of the exemplary embodiment, the connecting surface 112 is slightly inclined in relation to a plane running perpendicularly to the backrest pivot axis A, preferably by 1 to 5°. The basic body 22 of the fitting upper part 20 runs correspondingly obliquely.
[0066] In a further modification of the exemplary embodiment, instead of the three threaded bushings 142 , three bushings without an internal thread are provided as through bushings, and the three through holes 23 are replaced by three internal threads. The screw connection takes place in this case from the direction of the seat center.
[0067] Along the outer edge of the basic body 22 , the fitting upper part 20 has a flange 24 which runs perpendicularly to the basic body 22 and is oriented toward the outer side of the vehicle seat 1 .
[0068] The features disclosed in the above description, the claims and the drawings may be of significance both individually and in combination for realizing the invention in the various refinements thereof.
[0069] While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
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A composite component ( 110 ) for a vehicle seat ( 1 ), in particular for a motor vehicle seat, includes a plurality of fabric layers ( 116 ) of a fibrous material, a matrix material ( 118 ) securing the fabric layers ( 116 ), and an insert part ( 140 ), disposed between at least two of the fabric layers ( 116 ), for locally reinforcing the composite component. An insert strand ( 150 ) is disposed at least in sections along an edge or an edge surface ( 141.1 ) of the insert part ( 140 ). A vehicle seat ( 1 ) includes the composite component, in particular with a back structure ( 110 ) designed as a composite component.
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BACKGROUND OF THE INVENTION
This invention relates to offshore oil well operations and is specifically directed to a new and improved marine riser system for connecting marine risers extending from a well located on the ocean floor (subsea) to the platform of a vessel. Marine risers are sections of pipes sometimes called "conductors" or "casings" connected together as a "string" of "risers" and the vessels are suitably outfitted "ships" or "semi-submersibles", also referred to as "rigs".
In particular, the object of this invention is to provide a new and improved upper marine riser package which includes a self-tensioning riser slip joint and other equipment connectable, as a modular unit, to the upper end of the riser string and capable of being lowered through the rotary table on the vessel. Modularity of the package also facilitates retrieval for repair and maintenance.
This upper marine riser package may, in one application, eliminate all of the equipment of the conventional riser tensioning system, i.e., guide sheaves, wire ropes, and riser tensioners, as well as all of the necessary replacement equipment required to be stored on board the rig due to frequent breakage, such as extra reels of wire rope, extra sheaves, etc. In another application, this invention may be used where there are additional load requirements, such as in deeper water drilling, by providing additional load capabilities to the conventional riser tensioning systems. Thus, this invention can be used on newly constructed rigs either alone or as an addition to conventional tensioning systems or can be used as a retrofit for existing rigs to eliminate the conventional riser tensioning systems or as an addition to the conventional riser tensioning systems.
The need for slip joints and tensioning devices for marine risers supported from a platform of a vessel to a subsea well are amply described in any number of prior art patents such as in the U.S. Pat. No. 3,933,108 to Baugh directed to tanks to make the riser sections substantially bouyant, in the U.S. Pat. No. 4,367,981 to Shapiro directed to a slip joint form of a piston-cylinder configuration mounted at the upper portion of the riser, in the U.S. Pat. No. 3,353,851 to Vincent and in the U.S. Pat. No. 3,211,224 to Lacey, one of which shows a slip joint at the upper end of the riser string and the other at the lower end of the riser string.
However, none of the prior art patents cited above, as examples, suggest an upper marine riser package as an integral unit which could be made up and run, or retrieved for repair and maintenance, through the rig rotary table. Further, none of these patents suggest a package which, when used alone, would eliminate the aforementioned conventional riser tensioning systems or, alternatively, when used with such conventional systems, would provide additional load capabilities for longer and longer strings of risers for deeper and deeper subsea operations.
SUMMARY OF THE INVENTION
In the first embodiment of this invention, the upper marine riser package comprises four main components--a diverter, a flexible joint, a self-tensioning riser slip joint, and a riser rotation bearing joint, all of which may be lowered through the rotary table and supported on a diverter housing.
In use, the self-tensioning riser slip joint and the riser rotation bearing are connected as a modular unit to the upper end of a riser string, while the self-tensioning slip joint is being held in the marine riser handling spider on the drill floor of the rig. The flexible joint and diverter are then connected together and attached to the top of the self-tensioning riser slip joint. The entire package is then lowered through the diverter housing using a handling sub. The diverter lands in its housing and is locked down, thus supporting the entire upper marine riser package and all that it carries. Retrieval of the package for repair and maintenance is simply a reverse of the make-up procedure.
In the second embodiment of the invention, the upper marine riser package includes an upper ball joint and extension, in lieu of the flexible joint, which provides tilt action between the rig and the marine riser string, and is centrally apertured so that the self-tensioning riser slip joint and riser rotation bearing joint, as well as the risers, riser connection, etc., are lowered therethrough. The upper ball joint is installed in its housing which is attached to and supported by the drill floor substructure.
In use, the self-tensioning riser slip joint and the riser rotation bearing are connected as a modular unit to the upper end of a riser string and lowered through the rotary table and supported by the ball joint extension. Again, retrieval of the equipment for repair and maintenance is simply a reverse of the makeup procedure.
As will be understood by those skilled in the art from the Drawings and the Detailed Description hereinafter, both embodiments of the upper marine riser package of this invention has several unique features;
the diverter housing houses the diverter and supports the self-tensioning slip joint and riser rotation bearing as well as the risers, riser connectors, etc.,
the slip joint inner and outer barrels are keyed together to transmit initial vessel yaw or angular torque, thus relieving the cylinder rods of the slip joint from severe bending loads,
the riser rotation bearing joint at the lower end of the package handles large angular rotation of the vessel,
the self-tensioning joint is a compact module which with its multiple peripheral cylinders can be run through a rotary table and supported without complex handling procedures,
the multiple peripheral cylinders are designed for easy change out on the rig,
a hose/stab carrier, once installed, is a preassembly ready to interface with the upper riser,
the packer seal assemblies can be easily replaced through the diverter housing,
the locking mechanism which locks the slip joint in a lock-up position during the transporting stage is releasable by air/mechanical means, and
the upper stab subs and the lower extension subs of the cylinders engage the upper and lower support plates through their side slots and are finally secured by lock nuts in the same manner as a choke and kill line is secured.
Therefore, the principal advantages offered by the upper marine riser package are:
A. the unitization of upper riser components into a single package,
B. a more direct loading of supporting structure,
C. faster deployment of the slip joint,
D. less equipment and volume on the rig as compared to that of a conventional system,
E. the system is cost effective,
F. adaptable to deep water applications, and
G. is usable either alone, in place of the conventional riser tensioning system, or with conventional riser tensioning system to increase the load capabilities of the system.
In addition to the prior art patents mentioned above in the Background, there are also a number of patents which should be considered in connection with this invention.
Numerous attempts have been made to rid the vessel of the equipment in conventional riser tensioning systems. One such patent is the U.S. Pat. No. 4,215,950 to Stevens in which the elimination of the wire rope and sheaves was considered an important feature, but the tensioning cylinder and piston units, being coupled to and extending above the platform, interfere with other drilling operations and the handling of other equipment, such as the blow-out preventor stack, on the rig. Inasmuch as the peripheral cylinders of the present invention are completely free of the platform, there is no interference with other equipment being handled on the platform and/or being run through the risers during the operation. This feature is also important if the present invention is to be used with a conventional system to increase the load capabilities thereof, as mentioned above.
In the European patent application No. 0,088,608 of Elliston published Sept. 14, 1983 in bulletin 83/7, there is shown a motion compensating apparatus with a spherical or conical laminated body of superimposed layers of the elastomer material for a universal type joint. This joint is, first of all, above the floor and, secondly, does not permit the lowering of the flexible joint, the slip joint and other equipment through the diverter housing and rotary table or, in the case of the second embodiment, through the ball joint and rotary table. Swivel joints are shown in the U.S. Pat. No. 3,313,345 to Fischer. However, like the apparatus of the Elliston Application, the housing for such tilt joint and the tilt joint itself does not permit the lowering of the slip joint and other equipment through diverter housing and rotary table or, in the case of the second embodiment, through the ball joint and rotary table. Universal joints for riser strings are also shown in the U.S. Pat. No. 3,110,350 to Spieri, but again the concept of lowering the riser string, the slip joint, etc., through the diverter housing or rotary table or, in the case of the second embodiment, through the ball joint and rotary table, was not considered.
Reference should also be made to the U.S. Pat. No. 4,068,868 to Ohrt which shows a flexible joint used with conventional riser tensioning systems where the latter carry most of the load of the risers and other equipment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an overall elevational view of this invention in operating position,
FIG. 2 is an elevational view of the upper marine riser package of the first embodiment of this invention and of the area encircled by the arrow 2 and, enlarged over the view of FIG. 1, and shown with the self-tensioning slip joint in its lock-up position,
FIG. 3 is a schematic illustration of a conventional operator controlled pressure system,
FIG. 4 is a top plan view of the invention showing the bore of the diverter, taken along line 4--4 of FIG. 2,
FIG. 5 is a cross-sectional view showing the top of the flexible joint and taken along line 5--5 of FIG. 2,
FIG. 6 is a cross-sectional view of the hose/stab carrier, taken along line 6--6 of FIG. 2,
FIG. 7 is a cross-sectional view showing the connection of the stab subs to a retainer plate, taken along line 7--7 of FIG. 2,
FIG. 8 is a cross-sectional view showing the cylinder assemblies and connector assembly for the lower end of the cylinder assemblies, taken along line 8--8 of FIG. 2,
FIG. 9 is a cross-sectional view showing the top and bore of the rotation bearing joint, taken along line 9--9 of FIG. 2,
FIG. 10 is a cross-sectional view showing the gear system of the rotation bearing joint, taken along line 10--10 of FIG. 2,
FIG. 11 is an elevational cross-sectional view of part of the diverter, housing and flexible joint taken along line 11--11 of FIG. 4,
FIG. 12 is an elevational cross-sectional view of a diverter lock down dog, taken along line 12--12 of FIG. 4,
FIG. 13 is an elevational cross-sectional view of the lower flange of the flexible joint, carrier, packer seal assemblies, etc. taken along line 13--13 of FIG. 5,
FIG. 14 is an elevational cross-sectional view of the lock up dogs, the upper part of the cylinder assemblies and inner and outer barrels, taken along line 14--14 of FIG. 7,
FIG. 15 is a cross-sectional view of some of the lock-up dogs, taken along line 15--15 of FIG. 14,
FIG. 16 is an elevational cross-sectional view of one of the lock-up dogs, taken along line 16--16 of FIG. 15,
FIG. 17 is a view of the air manifold, taken along line 17--17 of FIG. 14,
FIG. 18 is a cross-sectional view of part of the reaction ring, taken along line 18--18 of FIG. 14,
FIG. 19 is an elevational cross-sectional view of the lower part of the cylinder assemblies attached to the outer barrel, taken along line 19--19 of FIG. 8,
FIG. 20 is a plan view of the snubber located at the lower end of the cylinder assemblies, taken along line 20--20 of FIG. 19,
FIG. 21 is an elevational cross-sectional view of the snubber, taken along line 21--21 of FIG. 20,
FIG. 22 is an elevational cross-sectional view of the rotation bearing joint, locking and unlocking devices, and gear system taken along line 22--22 of FIG. 9,
FIG. 23 is an elevational cross-sectional view of one locking/unlocking device shown in FIG. 22,
FIGS. 24-27 illustrate the steps in landing the upper marine riser package onto the hose/stab carrier first and then finally in the diverter housing,
FIG. 28 is an elevational view of the upper portion of the second embodiment of this invention,
FIG. 29 is a cross-sectional view taken along line 29--29 of FIG. 28,
FIG. 30 is a cross-sectional view taken along line 30--30 of FIG. 28,
FIG. 31 is an elevational, cross-sectional view of part of the diverter, diverter housing, and ball joint taken along line 31--31 of FIG. 29,
FIG. 32 is an elevational, cross-sectional view of the ball joint extension, locking ring, and packer seal assemblies, etc., taken along line 32--32 of FIG. 30, and
FIG. 33 is a perspective view of this invention as an addition to the conventional riser tensioning systems on a rig.
DETAILED DESCRIPTION
Referring to FIG. 1, vessel V is a drill ship (although a semi-submersible SS shown in phantom may also be used) and is shown floating on a body of water, such as an ocean. The vessel includes a vertical opening or "moon pool" M through its hull near the longitudinal and transverse center of the vessel. Supported on the upper deck of the vessel and approximately centered over the moon pool is a derrick from which the upper end of drill pipe P is supported by a traveling block T. The derrick and much of the associated equipment are of a type commonly used in offshore rotary drilling and are not shown in detail. Approximately centered in the base of the derrick are a support platform S, a riser handling spider HS, and a rotary table R. The drill pipe P passes vertically through aligned openings in the platform and rotary table and is rotated by the rotary table R in a standard manner. Anchors may be used to limit the movement of the vessel from its normal position over the well or, in deep water drilling, the vessel may be positioned dynamically.
A wellhead W is located on the submerged formation in which the hole is being drilled. The wellhead includes a base B and several lengths of well casing C extending beneath the wellhead into the well. In shallow water, drilling guide lines (not shown) extending between the vessel and the base B are used to guide equipment as it is lowered from the vessel to the wellhead, but in deep water drilling, such equipment is lowered and positioned on the wellhead by sonar, T.V., etc.
With the wellhead in place on the ocean bottom, a riser string RS, a lower marine riser package LMRP and blowout preventer BOP, are lowered to connect the vessel to the wellhead. This riser string is releasably connected at its lower end to the wellhead and is connected at its upper end to the vessel in a manner which will be described below.
High density drilling fluid from a mud system on the vessel is fed to the well from a pump to a drill bit DB at the bottom of the well and is returned to the sump by passing upwardly around the outside of drill pipe through well casings C, through the wellhead and then upward through the riser string where it is returned to the mud system.
As mentioned above, the upper end of the riser string is connected to the vessel, and this connection is accomplished preferably by an upper marine riser package (UMRP) 10 comprising this invention, shown in FIG. 1, connected to the support platform S. The first embodiment of this package 10 will be described in detail with reference to FIGS. 2-27.
First Embodiment--Flexible Joint Version
Thus, it can be seen that the upper marine riser package 10 includes four main components--a diverter D cooperable with a housing DH (FIGS. 2, 4, 11 and 12), a flexible joint FJ (FIGS. 2 and 11), a self-tensioning riser slip joint SJ (FIGS. 2, 5, 6, 7, 8, 13 and 21), and a riser rotation bearing joint RB (FIGS. 2, 9, 10, 22 and 23). In use, the self-tensioning riser slip joint SJ, and riser rotation bearing RB, can be connected, as a modular unit, to the upper end of the riser string. The flexible joint FJ and diverter D are then attached to the self-tensioning slip joint. As a package, it is then lowered through the rotary table of the rig with the diverter D finally locked in place in the diverter housing DH.
To facilitate understanding of the upper marine riser package 10, which will be described in detail hereinafter, FIGS. 2, 4 and 11 show the rig sub-structure or supporting structure S of diverter housing DH, attached thereto as by a fixture F, containing the diverter D to which is connected a flexible joint FJ (FIG. 11). The flexible joint FJ supports an upper spool 12 (FIGS. 13 and 14) which, in turn, supports: first, a fixed inner barrel 14 (the first part of the slip joint SJ), and second, a moveable outer barrel 16 telescoped over the inner barrel (the second part of the slip joint SJ), by multiple peripheral tensioning cylinder assemblies 20 (FIGS. 2 and 13-19). These tensioning cylinder assemblies 20 (presently eight in number although the number can vary), have their respective hollow piston rods 22 connected to the upper spool 12 while the respective outer cylinders 24 are connected to the moveable outer barrel 16 by connecting assembly 26 (FIG. 19). Double packer seal assemblies 30 (FIGS. 13 and 14) provide an annular seal between the inner barrel and outer barrel and, since the barrels are keyed together by slot and key assembly 32 (FIGS. 14 and 18), rotational torque is transmitted from the inner barrel to the outer barrel through riser rotation bearing joint RB to the riser when the vessel is used to orient the lower stack before landing on wellhead. The riser rotation bearing RB joint is equipped with locking/unlocking devices and a gear system assembly 36, which are used to orient the lower riser stack if the vessel is required to maintain the heading to the current or wind during a storm (FIGS. 2, 9, 22 and 23).
The upper marine riser package 10 is shown connected to the upper riser of riser string RS by a riser connector RC (FIGS. 2 and 22) and the slip joint SJ is held in fully retracted position, as shown in the drawings, by a plurality of outer lock-up dogs 42 located below the upper spool (FIGS. 15 and 16).
Now in more detail (FIGS. 4, 11 and 12), the housing DH is cylindrical, fixed to and extends downwardly through the rig sub-structure S, and is typically provided vents 44 and mud-flow outlets 46. The housing is attached to beams of the rig substructure slightly below the rotary table and houses the diverter D. The diverter D is typically a cylindrical ring 50 with an inner bore 52 with the operating apparatus therein. Only the ring 50 and bore are shown since the inner apparatus and its function is conventional. The outer wall of the cylindrical ring 50 is provided with a landing shoulder 54 which engages a radially inwardly extending landing edge 56, sometimes referred to as a landing profile, on the inner surface of the housing to limit the downward movement of the diverter D. This profile supports the entire package, risers, connectors, etc., during operation. A plurality of hydraulically actuated diverter lock-down dogs 60 are located around the outer periphery of the housing, extend through windows 62, and engage a plurality of locking grooves 64 formed on the outer wall of the diverter D to lock the diverter D within the housing DH. All hydraulically actuated lock-down dogs are identical and the cylinders thereof are connected by a pair of hydraulic lines 66 for extension and retraction of the lock-down dogs to an operator controlled pressure system 70 located on the rig and shown schematically as block diagrams in FIG. 3. Similarly connected hydraulically actuated lock dogs are shown in the U.S. Pat. No. 4,057,267 of Jones to which reference is made.
The function and operation of the diverter D is conventional. It is activated to vent uncontrolled formation gas out a line connected to the vent 44. This connection may also be used as a flushing line. Return mud flows out a line connected to outlet 46.
Attached to the lower end of the diverter D is a flexible joint FJ. To do this, the lower surface of the diverter D is provided with a plurality of threaded bores to receive the threaded ends of suitable bolts 72 (one shown) extending through a radially extending attaching flange 74 forming part of the flexible joint FJ.
The flexible joint FJ comprises two main body members, an upper body member 76 and a lower body member 80 which is telescoped within the upper body member 76 and separated therefrom to accommodate an elastomeric bearing assembly 82 and an elastomeric seal assembly 84.
The upper body member 76 is provided with an axial bore, the diameter of which is substantially coextensive with the inner bore of the diverter D and is provided with a radially narrow neck 86 immediately below the flange 74 to accommodate the heads of the bolts 72 attaching the flange 74 to the diverter D. The upper body member is also provided with a cylindrical downwardly opening housing 90 with its inner wall spaced from the lower body member 80 and encloses the bearing assembly 82 and seal assembly 84. The outer diameter of the outer wall of the housing 90 is substantially the same as the outer diameter of the flange 74, and has an outer bearing ring 92 suitably attached to its lower end as by a plurality of threaded bolts 94. The radially inner edge 96 of the bearing ring 92 is spaced from the lower body member 80 to provide a clearance for tilting movement of the lower body member relative to the upper body member 76. The bearing assembly 82, which includes the bearing ring 92 and the manner of operatively connecting the bearing assembly to the two main body members 76 and 80, are fully taught in the U.S. Pat. No. 4,068,868, supra, to which reference is made for more complete information concerning this bearing assembly 82. The sole difference between the bearing assembly of this invention and that discussed in the Patent is in the increased amount of loading on the bearing assembly in this invention. However, it is within the skill of those in the art to select the size, shape and type of materials to accommodate this increased load using the teaching of the Patent. See also the use of an elastomeric bearing in the U.S. Pat. No. 4,391,554 to Jones to which reference is made.
Also located on the upper end of the lower body member 80 is the aforementioned seal assembly 84 to prevent leakage from the interior of the flexible joint into the cavity within the housing 90. This seal assembly 84 permits relative flexing or tilting in all directions while maintaining the integrity of the seal. Again, reference is made to the U.S. Pat. No. 4,068,868, supra, which discusses a similar seal assembly and the manner of operatively connecting the seal to the two main body members 76 and 80, in detail.
The lower body member 80 (shown in two pieces welded together in FIG. 11) extends downwardly beyond the cylindrical housing 90 and terminates in a lower radially outwardly extending flange 100 (FIG. 13) which is bored and affixed by suitable bolt assemblies 102 to a flange 104 comprising the upper end of the upper spool 12.
The upper spool 12 is part of the self-tensioning slip joint SJ supporting the inner and outer barrels and tensioning cylinders, the bearing joint RB and the connected risers.
The upper spool 12 is a relatively long, relatively thick cylindrical ring, with an outer diameter substantially equal to the diameter of the diverter D. The outer periphery of the ring is configured to form the aforementioned flange 104 and to also provide a spider landing shoulder 106 to aid in making up the package. This make up procedure will be discussed in more detail later.
The inner bore of the spool is provided with a counterbore 110 which provides space for a landing ring 112 (inner barrel hanger). This landing ring 112 is locked into the inner barrel by a split ring 114 trapped in oppositely facing grooves on the ring and upper end of the inner barrel 14 and also contains a plurality of screws 116 (only one being shown) which engage threaded holes in the landing ring 112 and screwed to engage the mating slots in the upper end of the inner barrel 14, thus preventing the inner barrel from rotation or, as designed, making the inner barrel to rotate with the rig. The radially outer periphery of the landing ring is locked to the upper spool 12 by a key/slot and landing arrangement 120 and thus is keyed to the inner barrel. An insert piece 122 lands on the top of the inner barrel to provide an inner diameter approximately coextensive with the inner diameter of the inner barrel and bore of the flexible joint FJ. This insert extends upwardly into the bore of the lower body member 80 of the flexible joint and straddles the joint between the flange 100 and the flange 104 to provide a sealed bore. The insert 122 is held against movement by a split ring 124 disposed within oppositely facing grooves in the flange 100 and insert 122 and is locked in place by a second split locking wedge 126 and a resilient O-ring 130 disposed in the same groove in the insert. The O-ring pressures the locking wedge 126 upwardly behind the split ring 124, to retain the same position, but permits easy removal by withdrawal of the resilient O-ring 130. The lower end of the insert 122 has a shoulder 132 which engages the top edge of the inner barrel, and thus serves to restrain the inner barrel and lock ring 112 from upward movement. Suitable sealing means, such as O-ring seals, are provided to prevent leakage out between the flanges and elsewhere.
Surrounding the upper spool 12 is a cylindrical carrier 140 comprising a wall which extends from approximately the lower end of the upper spool 12 to approximately the upper end of the upper spool 12. Approximately the lower half portion 142 of the carrier is thicker than the remainder of the ring and is a sliding fit with the outer surface of the upper spool. The mid portion 144 of the carrier has a larger radial inner diameter than that of the lower portion and extends upwardly to terminate in a upwardly facing funnel 146. The mid portion 144 joins the lower end of the diverter housing DH and the funnel 146 aids in guiding the carrier around the diverter housing DH. A drain passage 148 is located between the lower and mid portions of the carrier. This carrier 140 has thus two positions--a stored position attached to the diverter housing DH, and an operating position surrounding the upper spool. The two positions of this carrier are part of the makeup procedure of the package which will be described later. The lower end of the carrier 140 also has an inner landing profile 150 which is engaged by a radial shoulder 152 on the upper spool 12 when the upper spool is landed within the carrier as shown in FIG. 13.
In the mid portion 144 of the carrier 140, a plurality of hydraulically actuated locking dogs 154 are located circumferentially of the ring. These dogs are used to attach the carrier to the diverter housing. Since all the locking dogs and their hydraulic actuating are identical, only one will be described. Thus, each locking dog moves in and out through a window 156 in the carrier to engage and disengage mating grooves 160 (FIGS. 2 and 11) in the outer periphery of the housing DH and the cylinder 158 is connected by a pair of lines 162 to the same operator controlled system 70 located on the rig. Thus, these locking dogs are similar in function and operation to the previously described locking dogs 60.
At the lower portion 142 of the carrier, there is provided a plurality of hose/stab assemblies 164 positioned on a clamping ring 166. The clamping ring 166 is formed in halves and bolted together to clamp around the outer periphery of the carrier 140 and is positioned thereon by a circular key and slot arrangement 170. The clamping ring is provided with radially outwardly extending cavities 172, also formed in two halves bolted together and welded to the clamping ring to engage the outer periphery of the housing 174 of the hose/stab assemblies 164.
Since all the hose/stab assemblies are identical, only one will be described. Thus, each hose/stab assembly 164 has a hollow stab (tubing) 176 moveable radially inwardly and outwardly through windows 180 in the clamping ring 166 and carrier 140, respectively, and into and out of a suitable horizontal port 182 in the upper spool 12. Windows 180 are larger than the outer diameter of the stabs 176 to allow the stabs to "float" to compensate for tolerance variations in the carrier, clamping ring and the port 182. The O-rings, positioned in the port, sea against the stab to prevent leakage from the port 182. The stab is a hollow rod integral to a piston 184 reciprocable in a chamber in response to hydraulic fluid entering the chamber on either side of the piston from a pair of hydraulic lines 186 connected to a chamber and to a source of fluid under pressure. The chamber is also connected to hydraulic fluid under pressure through a line 190 connected to a coupling 192 located on the end of the housing. This latter fluid under pressure enters the chamber, passes through the piston via the hollow tube and into the port 182 of the upper spool 12. So that the piston will not be responsive to this latter fluid pressure, the piston is hydraulically balanced and is thus responsive only to the fluid in the two lines 186 for movement of the stab in and out of the upper spool. The source of hydraulic fluid under pressure for lines 186 and 190 is the same operator controlled pressure system 70, supra.
The mid portion 144 of the carrier 140 is also provided with a plurality of hydraulically actuated locking dogs 194 (FIGS. 2 and 6) interspersed between the hose/stab assemblies (four of such locking dogs being shown, although their number could vary) to engage a suitable groove 196 (FIG. 13) in the upper spool 12 to lock the carrier onto the upper spool when the carrier is released from the diverter housing, so that the dynamic load of the carrier is not imposed on the hydraulic stabs 176.
The hydraulic apparatus for actuating these locking dogs 194 is the same as the previously described locking dogs and is connected by a pair of hydraulic lines 198 to the operator controlled pressure system 70. Therefore, no further description is deemed necessary.
Thus, it should be apparent that the locking dogs 154 located on the mid portion of the rig are used to lock the carrier onto the diverter housing DH before and when the upper spool lands in the carrier. Once the upper spool has landed in the carrier with proper orientation, the four locking dogs 194 on the lower portion of the carrier are activated to lock the carrier onto the upper spool. Then, the hollow stabs 176 are pressured to stab into their corresponding ports. The next step is to retract the upper locking dogs 154 from the diverter housing DH allowing the carrier and hose/stab assemblies to lower with the upper spool until the diverter itself has landed on the diverter landing profile 56. This is the position of the upper spool as shown in FIG. 13.
Also as shown in FIG. 13, the horizontal ports 182 on the upper spool 12 and their stabs 176 communicate with vertical ports 200 on the upper spool 12 which in turn are connected to the hollow piston rods 22 of the tensioning cylinder assemblies 20 forming part of the self-tensioning slip joint SJ. These tensioning cylinder assemblies 20 and how they are attached and operate in the package will now be described. It is understood, of course, that the length of the cylinder assemblies is commensurate with the amount of vertical movement due to the heave of the vessel during operation.
The lower end of the inner bore of the upper spool 12 is counterbored and threaded as at 202 to receive an externally threaded inner sleeve 204, which has an inner diameter coextensive with the inner diameter of the upper spool and which telescopes over the outer diameter of the outer barrel 16 to accommodate the outer barrel 16. This sleeve 204 is provided with an upwardly facing ledge 206 formed by reducing the outer wall of the sleeve. A stab sub supporting plate 210 (FIGS. 7 and 13) seats on this ledge and supports cylindrical hollow stab subs 212 (eight in number although their number may vary), as well as the hollow piston rod 22 coupled thereto. The sleeve 204, the stab sub support plate 210 and the supporting ribs 214 are an assembled part which is subsequently welded to the low end of the upper spool to form a rigid support for the cylinder assemblies. Since all stab subs are identical, only one will be described. Thus, the stab sub 212 has a smooth outer surface at its top end 216 and is insertable in the vertical port 200 (one shown in FIG. 13). Suitable O-ring seals are positioned in the port 200 to form a liquid tight connection. The stab sub 212 is internally threaded at its lower end, as at 220 (FIG. 14), to engage mating external threads on the upper end of the hollow piston rod 22. The stab sub is also provided with external threads 222 at its mid portion on which a clamping nut 224 is threaded. The clamping nut 224 engages the upper surface of the stab sub supporting plate 210 and, together with a stop (ledge) 226 on the stab sub, hold the stab subs in place after having been inserted into the vertical bore 200 in the upper spool 12. The stab sub supporting ring 210 has a radially opening groove 230 (FIG. 7) to allow the stab subs to be inserted and removed from the stab sub support plate 210. The lower end of the tensioning cylinder assemblies 20 are removeable at the connection assembly 26 also for this purpose. Thus, when the clamping nut 224 is backed off out of engagement with the stab sub supporting plate 210, the stab sub/hollow piston rod 22 can be lowered to allow removal of the stab sub from the upper spool, and the stab sub, together with the cylinder assemblies 20, can be pulled outwardly for removal and repair. Making up the connection of the cylinder assembly 20 and stab sub is a reverse procedure. The disconnection of the cylinder assembly 20 from the connecting assembly 26 will be described later.
The outer barrel lock-up dogs 42 (eight used, but their number can vary) are spaced peripherally between the stab subs and located below the stab supporting plate 210. Their purpose is to hold the outer barrel in position until the cylinder assemblies 20 are pressurized. Since all eight lock-up dogs 42 are identical, only one will be described (FIGS. 15 and 16). Thus, each dog 42 is moveable radially in and out of engagement with a plurality of grooves 232 formed in the outer barrel through a window 234 in the sleeve 204. Each dog 42 is coupled by a retainer head and groove assembly 236 to an actuating screw 240 threaded for rotation within a threaded bore in a support plate 242 fixed to the sleeve 204. The screw is rotated by a shaft 244 by an air motor 246 driving a gear box 248 to move the dog 42 radially in and out of engagement with grooves 232. The air motor/gear reducer combination is suitably fixed to the support plate 242 and air under pressure is supplied to the motor via air supply line 250 connected to the operator controlled pressure system 70 on the rig. Exhaust 252 is part of the motor.
Below the lock up dogs 42 is a stabilizing ring 260 clamped to the outer barrel 16 to hold (centralize) the cylinder assemblies 20 relative to the outer barrel. This stabilizing ring 260 is formed in halves with radial flanges (not shown) bolted together and is provided with radially opening slots 262 to allow the cylinder assemblies 20 to be removed for repair and replacement. The stabilizing ring 260 is similar to the stab sub supporting plate 210 of FIG. 7 and thus is not shown in plan view and, again, since all eight cylinder assemblies 20 are identical, only one will be described.
As shown in FIG. 14, each outer cylinder 24 of each cylinder assembly 20 is closed at its upper end by a centrally apertured cylinder head 264 inserted within the cylinder 24 and held in place by the combination of a positioning ring 266 and a bushing 270, which engages a shoulder on the cylinder head and which is fixed thereto by set screws 272. Both the inner wall of the cylinder, the cylinder head, and the bushing have semi-circular grooves to collectively receive the positioning ring 266. A plurality of resilient seals in the aperture of the cylinder sealingly engage the piston rod and allow axial movement therein. As shown in FIGS. 19-21, a slideable piston 274 is fixed to the lower end of the piston rod 22 and provided with resilient seals which sealingly engage the inner wall of the cylinder in a conventional manner. Suitably attached to the top of the piston, as by bolts 276 is a snubber 280. This snubber 280 is a barrel-like member, having a conically formed outer surface 282 which will be received in the downwardly facing hollow cup-like area 284 of the cylinder head 264. The snubber and cup-like area will cushion the fall of the cylinder head if the cylinder assemblies were to lose hydraulic pressure at any time. The piston is also provided with radial passages 286 which communicate with vertical passages 290 in the snubber. Fluid from the operator controlled pressure system 70 communicated through the upper spool, through the hollow piston rod and through passages 286 and 290 which open into the upper chamber formed by the piston, cylinder wall and cylinder head.
The lower end of the cylinder assembly is closed in a manner similar to the manner in which the cylinder head is attached, that is, ring 292, having a central aperture 294, is inserted in the cylinder, is held against a positioning ring 296 by an internally threaded extension sub or cap 300 which is bolted to the ring 292 and has a ledge 418 which engages the end of the cylinder. Suitable grooves in the ring 292, the extension sub 300, and the cylinder wall hold the positioning ring in place. The extension sub 300 has a reduced portion which is externally threaded as at 304 and is long enough to extend beyond support plate 306, formed as an integral part of the outer barrel as a forged ring welded to the outer barrel. This forged ring is part of the previously mentioned connecting assembly 26 and is braced for strength by a plurality of strengthening ribs 310. The plate 306 is provided with radially outwardly open slots 312 (FIG. 8) to allow insertion and threaded extension sub 300. A retainer head 314 beneath the plate 306 cooperates with a nut 316 which is rotated downward to fasten the extension sub 300 to the support plate. The retainer head 314 seats in the counterbore 320 in the lower face of the support plate, thus securing itself and the extension sub on the plate.
To remove the cylinder assembly, the nut 316 is threaded upwardly and then, the nut 224 on the stab sub 212 at the upper end of the assembly is also threaded upwardly allowing the stab sub to drop clear of the port so that the assembly can be maneuvered out through the slots of the upper and lower support plates.
Both the ring 292 and the extension sub 300 are internally axially bored and connected to a pair of L-couplings 322 which are connected to a hose 324 which extends upwardly between adjacent cylinder assemblies 20. The upper end of the hose 324 (FIGS. 2, 16 and 17) is connected to a hollow ring manifold 326 located about the cylinder assemblies and below the lock-up dogs 42. This manifold surrounds the outer barrel and is connected in any suitable manner as by bolting to the stabilizing ring 260. The manifold also has large exhaust lines 330 connected by hoses to the rig. Thus, air trapped in the chamber of the cylinder 24 below the piston 274 is vented to the manifold and to the surface via the bores in the ring 292 and extension sub 300 and out through the hoses 324. Air in the manifold is vented to the surface via the exhaust lines 330.
Referring again to FIGS. 13, 14 and 16, when the outer barrel is in lock-up position, as shown, the double packer seal assemblies 30, providing the annular seal between the inner and outer barrels, are located in the same vertical position as the upper spool and its extension. On top of the outer barrel 16 is a hollow, cylindrical packer gland 340 which houses the double packer seal asemblies 30. The packer gland 340 is attached to a radial flange 342 on the top end of the outer barrel by bolts 344 (FIG. 14). A stepped bearing ring 346 on the lower end of the lower packer seal 350 lands on a stepped ledge 352 formed on the packer gland. The upper end of the lower packer seal 350 is provided with a second bearing ring 354 having a plurality of J-slots 356 (with only the vertical groove of only one J-slot being shown) to receive a pin 360 on still another bearing ring 362 which partly extends into the bearing ring 354. The pin in the J-slot 356 locks the two rings together during installation and also against relative rotation, but allows the two rings to be separated if necessary. The bearing ring 362 belongs to the upper packer seal 364. Attached to the upper end of the upper packer seal 364 is a fourth bearing ring 366, identical to the bearing ring 354. A lockdown ring 370 has external threads 372 to engage internal threads on the upper end of the packer gland and has a plurality of J-slots 374 (again, only one being shown) by which a running tool can rotate this lockdown ring 370, and thread the lockdown ring into the outer barrel to hold the double packer seal assembly in place and to force expansion of both upper and lower packer elements. This same running tool can be used to retrieve replacement since all J-slots are identical.
Either one of the double packer seals can be pressured from behind against the inner barrel by air under pressure from a suitable source. In this embodiment, and as shown in FIGS. 13 and 16, the packer gland is provided with two passages 380 and 382 extending from below lock-up dogs 42 to the packer seals. Passage 380 extends to the middle of the lower packer element 342 and the other passage 382 extends to the middle of the upper packer element 354. Both passages extend through an enlarged radius 384 on the outer barrel and through the packer gland 340 (passage 380 more clearly shown in FIG. 16) via a crossover tube 386, and are connected by air lines through hoses 390 to the rig where there are attached to a source of air pressure, such as an accumulator or to the operator controlled pressure system 70. Drilling fluid will enter the space between the inner and outer barrels, by reason of apertures 392 (FIG. 19) in the inner barrel 16 during operation, thus helping to lubricate the packing elements.
As previously mentioned, the outer and inner barrel are keyed together by key assembly 32. The key assembly comprises an elongated keys 400 on the outer barrel 16 and which extend the full length of the stroke of the slip joint and are attached to the outer barrel by plug wells 402 (FIGS. 14, 16 and 18). These keys 400 slide within key slot 404 formed in the inner barrel shoe 406 (FIG. 19) and also in a reaction ring 410 (FIGS. 14 and 18). The reaction ring on inner barrel also serves as a stopper for the slip joint when it comes in contact with the lower ledge 412 (FIG. 16) of the packer gland. Since the two barrels are keyed together, the aforementioned riser rotation bearing joint RB is appropriate to transmit torque from the outer barrel to the inner barrel due to rig rotation. This riser rotation bearing joint RB will now be described.
As shown in FIGS. 19 and 22, the riser rotation bearing RB comprises two telescoped tubular body members 420 and 422. The upper tubular body member 420 has a reduced portion which is welded to the outer barrel 16 and which terminates in a radial flange 424. An outer cup-like housing 426 is attached by bolts 430 (one shown) to the bottom of the flange. The outer wall of the housing 426 is spaced from the lower tubular body member 422 and terminates in a radially inwardly extending wall 432 and a barrel extension 434 which engages the outer lower body member in rotatable relationship. Wall 426 defines an oil filled cavity 436 which houses a spherical roller thrust bearing assembly 440. The upper end portion of the lower tubular body member is reduced as at 442 and is telescoped within a counterbore 444 in the upper tubular body member 420. A suitable low friction ring bearing 446, a thrust spacer or cushion ring 450, and suitable seals 452 provide free fluid tight rotation between the two tubular body members. Below the reduced upper end portion 442, the lower tubular body member is provided with a split ring 454 located in a circumferential groove 456 in the lower tubular body member and bolted as at 460 to the top race of the bearing assembly. The split ring 454 and bolt 460 retain the spherical roller bearings, bearing races, etc., of the spherical roller thrust bearing assembly 440 in place to operatively function, as such, between the upper and lower tubular body members. Suitable rotary seals 462 between the barrel 434 and lower tubular body member provide a fluid tight relationship between the housing and lower tubular body member.
The assembly comprising the locking/unlocking devices and gear system 36 are located below the riser rotation bearing joint RB and is used to orient the lower riser stack if the vessel is required to maintain heading to the current or wind during a storm.
As shown in FIG. 22, a second outer housing 464 whose outer wall is coextensive with the outer wall of the housing 424 of the bearing joint, is attached to the housing 426 by bolts 466. This housing encloses the loading/unloading devices and part of the gear system. Since there are a plurality of these devices located circumferentially of the lower tubular body member, only one is described and shown. Thus, in FIGS. 22 and 23 it can be seen to comprise a locking pin 470 moved into and out of engagement within a suitable bore 472 in the lower tubular body member by a hydraulic cylinder 474. Its piston 476, connected to the pin 470 by a retainer head and groove arrangement 480, is biased by a spring 482 outwardly from the bore 472. The cylinder is hydraulically connected by a suitable hydraulic line 484 to the operator controlled pressure system 70 on the rig. Thus, the spring 482 urges the locking pin 470 out of engagement with the bore 472 and the hydraulic pressure is used to urge the lock pin into the bore. A pin 486 signals the position of the locking pin 470. Attached to the lower radially inward wall 490 of the housing below the locking/unlocking devices is the gear system of assembly 36 which comprises a pair of hydraulic motors 492 (FIGS. 10 and 22). Each motor shaft 494 drives a pinion gear 496 which meshes with a ring gear 500 fixedly attached to the lower tubular body member 422 by drive keys 502 so that rotation of the motor shafts rotate the tubular member 422 relative to the upper tubular body member 420 when the lock pins 470 are withdrawn from the tubular body member. Each motor is hydraulically connected by branch lines 504 to a main line 506 to connect the operator controlled pressure system 70. Rotation of the lower tubular body member is incremental depending on the circumferential spacing of the locking bores 472.
As mentioned previously, FIGS. 2, 13 and 16 illustrate the lock-up dogs 46, air pressure actuated and holding the slip joint SJ in lock-up position as it would be during installation or retrieval. Attention is now directed to FIGS. 24-27 for the steps in making up the upper marine riser package. FIG. 24 illustrates the carrier 140 locked onto the diverter housing DH by lock-up dogs 154. The slip joint SJ and riser rotation bearing RB were first made up, connected to the riser connector RC (FIGS. 2 and 22), and held by the marine riser handling spider HS engaging the spider landing shoulder 106 on the upper spool 12 (FIG. 13). At this time, the carrier 140 is still locked on the diverter housing DH. Next, the diverter D and flex joint FJ are brought over and attached to the upper spool with mating flanges 100, 104. Once this is done, the upper spool is then freed of the riser handling spider HS and lowered through the rotary table until the landing surface 152 on the upper spool orients and lands on the profile 150 of the carrier 140 (FIG. 25). Then, the locking dogs 194 are hydraulically actuated to lock the upper spool 12 onto the carrier 140. This is followed by extending the stab subs 176 into their respective ports through hydraulic actuation of the lines 186. The locking dogs 154 are then retracted and the entire package is lowered until the diverter landing surface 54 lands on the profile 56 on the diverter housing (FIG. 26). The diverter lock-up dogs 60 are then actuated to lock the diverter D in the diverter housing DH. Then, for operation of the self-tensioning slip joint SJ, fluid pressure is applied to the cylinder assemblies 20 to ensure that the slip joint SJ would not drop the full stroke of the piston rods. The applied pressure will be high enough to apply greater tension on the riser string than for normal operation and then the control operator will release the lock-up dogs 42 by air pressure releasing the outer barrel to allow the outer barrel to descend gently by bleeding pressure from the cylinder asemblies till the BOP stack lands and locks on the wellhead. Another possibility is that after the applied pressure is raised above normal, the derrick will be used to support some of the load of the riser string while the control operator releases the lock up dogs 42 and bleeds pressure from the cylinder assemblies to allow the outer barrel to descend gently. Thereafter, the slip joint is set and tensioned at mid stroke, compensating for the rise and fall of the vessel due to tides, waves, and the like to keep the riser string in constant tension.
If it is desired to retrieve the upper marine riser package for any reason, the riser string RS is disconnected at the wellhead and additional fluid pressure is then applied to the cylinder assemblies 20 to raise the outer barrel to the position as shown in FIG. 26 where the lock-up dogs 42 can again lock the outer barrel in position. Once the outer barrel is locked in place, and after the diverter lockdown dogs 60 are hydraulically withdrawn, the entire package, including the carrier 140, is raised by handling sub until the locking dogs 154 are level with the grooves 160 on the diverter housing, at which time the locking dogs 154 are pressured into the grooves. The diverter and flexible joint can then be removed separately or together from the upper housing spool 12. Removal of the flexible joint also withdraws the insert 122.
It is important to note that, in connection with this retrieval procedure, that none of the major hydraulic or air connections to the upper marine riser package need to be disconnected, except for a few small air or hydraulic lines that are equipped with quick-disconnect unions.
If it is desired to remove and replace the packer seal assemblies while the upper spool is held by the riser handling spider, a running tool may be inserted into the bore of the inner barrel (the insert 122 having been removed) where it engages a downwardly facing surface 510 (FIG. 13). This downwardly facing surface was previously used to assemble the inner barrel within the outer barrel. With the downwardly facing surface 510 thus engaged, the inner barrel, together with its hanger 112, are hauled through the upper spool to rest the inner barrel hanger on handling spider. The inner barrel is disconnected from its hanger by removing the screws 116 and the split ring 114. Once the inner barrel is freed from it hanger, it is lowered, to free stand on the ledge 512 of outer barrel (FIG. 19). The top of the inner barrel is now below the packer seals, giving that area an open hole. At this time, a J-tool could then engage the J-slots 374 on the top ring 370 of the packer assembly and rotate the top ring so that ring 370 can be removed. Use the same J-tool to retrieve the first packer element or together with the second packer element for repair and replacement.
While the upper marine riser package is in its upper position, it may be feasible to remove any or all of the cylinder assemblies 20 for inspection, repair and/or replacement.
Second Embodiment--Ball Joint Version
Turning now to FIGS. 28-32, there is shown, in part, another embodiment of the upper marine riser package, identified as 10A. In this embodiment, the flexible joint FJ is replaced by a ball joint BJ and modifications are made in the diverter housing DH to the upper spool 12. The remainder of the upper marine riser package remains the same. To simplify the description of this embodiment, the suffix A will be added to those parts which are modified but perform a similar function as those parts described previously. Those parts in this embodiment which are exactly the same in both embodiments will be given the same reference numeral. Thus, the diverter housing DHA comprises an inner cylindrical diverter housing 520, a support frame or ring 522 spaced therefrom, a cylindrical ball joint housing 524 and vent and mud flow connections 44 and 46. The ball joint housing 524 is mounted to the rig platform S by a bolt/flange arrangement as previously described for the first embodiment. The inner wall of the diverter housing 520 is provided with an upwardly facing landing profile 56 for the landing surface 54 on the diverter outer wall. The upper end of the diverter housing 520 is connected to a support frame 522 by a plurality of radially oriented gussets 526. The support frame has a downwardly facing landing surface 530 which engages an upwardly facing profile 532 on the ball joint housing 524 so that the support frame 522 supports the diverter housing. The diverter housing is locked by a plurality of hydraulically actuated lock dogs 534 extending through the ball joint housing and engaging an upwardly facing ledge 536 on the support frame. The hydraulic actuators for the lock down dogs 534 are similar to actuators for the locking dogs 154 shown in FIG. 13.
Between the two housings, connections 44A and 46A are provided for the diversion of gas and drilling mud through the vents 44 and 46 similar to that of FIGS. 2 and 11. Suitable seals, such as metallic seals 540 and O-ring seals, prevent leakage from the outlets. The diverter is locked in its housing by lockdown dogs 60 which engage grooves 64 in the diverter outer wall in a manner similar to that previously described.
The lower end of the ball joint housing 524 is thickened so that its inner surface extends radially inwardly to form a socket 542. To facilitate tilting movement of the ball joint, a replaceable bearing insert 546 coated with TFE based material for low friction is provided between the main ball body 550 and the socket 542. The main ball body 550 is hemispherical on both its inner and outer surfaces 552 and 554. A radially smaller hemispherical segment 556 engages the inner surface 554 and has a cylindrical extension 560 extending upwardly within the diverter housing 520. The diverter housing has an enlarged radius 562 to accommodate the cylindrical extension so that the inner surface of the remainder of the diverter housing and the inner surface of the extension are radially equal to present a smooth bore for the diverter. The smaller hemispherical segment 556 allows tilting action of the main ball body in its socket since the hemispherical segment and its extension are fixed vertically by the diverter housing and rotationally by a anti-rotation pin 564 within a relatively long vertical slot 566 in the diverter housing. Any wear of the bearing inserts 546, the main ball joint segment 550, or on the surface of the hemispherical segment 556 will be accommodated by downward movement of the segment 556 and its extension 560. Suitable sealing means, such as O-ring seals, are disposed in the surface of the hemispherical segment and between the extension and inner wall of the enlarged radius 562 to seal against leakage through the ball joint. A ring 570 is fixed to the top surface of the main ball segment, as by bolts 572, and has a radially extending anti-rotation pin 574 threaded in the ring and extending therefrom into a vertical slot 576 in the outer cylinder to prevent rotational movement, yet allow tilting movement of the ball joint on two axes.
The main ball segment 550 has a cylindrical extension 580 directed downwardly and shown integral therewith (FIG. 32). Near its lower end, the extension 580 has a landing profile 150 on its inner wall which engages a shoulder 152 on the upper spool 12A when the upper spool 12A is oriented and landed in the extension. The upper spool 12A serves the same functions as were previously described in the first embodiment, except that the tension load is now transmitted through the ball joint housing 524 to the rig structure, and not through the diverter housing 520. The sequence of installation is also different. The upper large ball joint is, in this case, installed together with hose/stab assembly 164 as a ready package to receive the self-tensioning slip joint SJ.
The upper spool 12A, as in the first embodiment, is part of the self-tensioning slip joint SJ supporting the inner and outer barrels 14 and 16, the tensioning cylinder assemblies 20, the bearing joint RB and the connected risers.
After landing the upper spool 12A, a spool lock-down ring 582 is landed in the ball joint segment extension 580, the inner barrel lock-down dogs 194 are then actuated through windows in the extension to engage mating grooves in the lock-down ring 582, except that the lock-down dogs 194 engage the lock-down ring instead of the upper spool itself. These dogs and their hydraulic actuators are the same type as those described in the first embodiment and need not be described further. This lock-down ring 582 restrains the upper spool from upward movement and its inner wall is provided with gussets 584 to support an inner ring 586. Also, a funnel 590 welded to the two ring 582 and 586 seals off the areas below the diverter by means of an O-ring seal in a ring 610 attached to the outer periphery of the funnel. The inner ring 586 has a thickened portion 592 which extends radially inwardly over an inner barrel hanger 594, thus preventing the inner barrel from upward movement during operation. More precisely, inner ring 586 engages the upper edge of the inner barrel hanger 594 while the latter has a reduced portion forming a downwardly facing surface 596 which engages the top end of the inner barrel. The inside diameters of the ring 586 and the inner barrel hanger 594 coincide with the inner diameter of the inner barrel.
Above the inner barrel hanger 594 and above the radially inner thickened portion 592, the inner ring 586 is provided with a J-slot 600 with a long upwardly extending slot opening to receive a pin 602 in a wear bushing 604. Wear bushing 604 lands within the inner barrel and engages a landing shoulder 606 on the inner ring 586. Suitable seals such as O-ring seals are installed to prevent leakage. J-slots 612 are provided in the vertical portion of the wear bushing 604 for independent removal of the bushing with a running tool.
The upper portion of the upper spool 12A is bored and provided with internal threads 656 to engage mating threads on a running tool for running and retrieving of the self-tensioning slip joint through the rotary table. Retrieving would take place after removal of the wear bushing 604 and lockdown ring 582.
The inner barrel hanger 594 is prevented from rotation by vertical pins 616 in the upper spool extending through a relatively thin ring 620 forming the lower portion of the inner barrel hanger. This ring 620 rests on the upper spool and is attached to a vertical cylindrical ring 622 which is welded to the main ring 624 of the hanger. This main ring 624 has a plurality of threaded bores into which bolts 626 are threaded to engage bores 630 in the inner barrel to hold the latter relative to the hanger. A vertical cylindrical extension 632 on the ring provides the downwardly facing surface 596 which engages the upper edge of the inner barrel to lock the inner barrel against upward movement.
As can be seen from the drawing, the lower end of the bore of the upper spool is counterbored and threaded, as at 202, to receive the threaded inner sleeve 204. This sleeve and the slip joint are the same as previously described and need not be further described at this point.
Also, it should be apparent that after the spool lock-down ring 582 and wear bushing 604 have been landed, the diverter D is locked down in the diverter housing 520 by diverter lock-down dogs 60.
Since the upper spool 12A at its attendant apparatus and the ball joint BJ differ from the first embodiment, retrieval will necessarily be different.
Now to the method of retrieval, if it is desired to retrieve the upper marine riser package 10A for any reason, the riser string is disconnected at the wellhead and fluid pressure is then applied to the cylinder assemblies 20 to raise the outer barrel to the position where, as before, the lock up dogs 60 can again lock the outer barrel 16 in retracted position. In this position, the diverter lock down dogs 60 are retracted so that the diverter D can be withdrawn from the housing DHA.
After the lockdown block 582 has been removed, the upper spool 12A, the packer seal assemblies 30, and the inner and outer barrels 14 and 16 may be retrieved through the diverter housing 520. If it is required, the diverter housing 522 itself with the hemispherical segment 556 may be withdrawn, with or without the diverter remaining inside, simply by retracting those locking dogs in the locking device 534.
If it is desired to remove the ball body and its extension, the inner spool lockdown dogs 194 will be retracted and a running tool engages the J-slots 612 in the wear bushing to withdraw the wear bushing and lockdown block 582 exposing the threads 656 on the upper spool. A running tool will engage the threads 656 and withdraw the upper spool, together with the self-tensioning slip joint and riser string. At this time, the main ball segment 550 can be removed for service or for replacing the bearing insert 546.
In order to change the packer seal assembly, the diverter and the lock down ring 582 and wear bushing 604 must first be removed. A tool is lowered to engage the surface 596 on the inner barrel and retrieve the inner barrel hanger 594 onto the handling spider. While the inner barrel is partially supported by the retrieving tool, the bolts 626 are removed from the slots 630 on the inner barrel separating the hanger from the inner barrel which is then lowered down to free-stand inside the outer barrel below the packer seal assembly. Thus, the J-slots in the upper stepped ring of the packer seal assembly is exposed. A running tool can engage these J-slots, rotate the upper rings and remove the packer seal assemblies.
Therefore, it can be seen that the marine package is easily made up and easily retrievable for repair and maintenance in a manner similar to the repair and maintenance of the first embodiment, except for the details required because of the difference between the ball joint and the flex joint.
As mentioned previously, the upper marine riser package 10 or 10A may be used to rid the rig of the equipment necessary to operate the conventional riser tensioning system or, since the package is completely, or substantially completely, below the platform of the rig, it can be used as an addition to the conventional riser tensioning system to provide greater load capabilities for the tensioning system. To accomplish this, attention is now directed to FIG. 33 which shows the derrick, traveling block T and support platforms previously referred to in FIG. 1. The traveling block T is provided with a motion compensator unit 640 and accumulator 642 for vessel motion compensation for the drill pipe P (not shown in this Figure). In this Figure, the riser tensioner units 644, idler sheaves 646, operator controlled pressure system 70 to control fluid supply unit 650, air dryer/compressor unit 652 and air bottle assembly 654 for the conventional riser system are shown. The wire rope 656 for connecting the conventional riser tensioning system is shown connected to a tensioning ring 660 in the conventional manner. Thus far described, the system is conventional; however, also shown is the upper marine riser package 10 which is used in conjunction with the conventional riser tensioning system. Since both are connected to the same operator control panel 70 and to the same fluid and air supply system the two are compatible to increase the load capabilities of the rig for deeper and deeper water operations.
The foregoing teaches those skilled in this art about apparatus and methods of running a marine riser package through a confined space in a floating rig; however, it should also be apparent that a self tensioning slip joint made up of a plurality of peripheral cylinder assemblies, such as disclosed, which is supported and operated below the rig, is useful apart from the disclosed package and an operator may use other equipment than that disclosed to support such a slip joint in operation.
It should also be apparent to those skilled in the art that there are a number of individual features which are unique and useable apart from the two embodiments of the upper marine riser packages disclosed. These are:
the hose/stab assemblies,
the combination of the hose/stab assemblies and the upper spools as a means of communicating fluid pressure to the cylinder assemblies,
the key slot assembly between the inner and outer barrels of the slip joint,
the cylinder assemblies having hollow piston rods as a means of communicating fluid pressure to the cylinder assembly chambers,
the connection of the cylinder assemblies to the slip joint and the ability to change the individual cylinder assemblies,
the manner in which the packer seals may be changed, that is, centrally and upwardly from between the inner and outer barrels,
lock dogs which are air motor driven,
the manner of arranging the slip joint wherein the inner barrel does not support the load (riser strings, etc.) in operation,
the rotation bearing in a slip joint with or without the lock/unlock devices and gear assembly, and
the lock/unlock devices and gear assembly to rotate the riser string relative to the floating vessel.
Finally, while the foregoing continually refers to drilling risers, it should also be apparent to those skilled in the art that the upper marine riser package of this invention may also be used with production or sales risers.
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An upper marine riser package (10/10A) comprising a diverter (D) for diverting uncontrolled gas and return drilling mud therethrough, a flexible joint FJ for allowing tilting motion between a vessel and a riser string (RS), a self-tensioning slip joint (SJ) and riser rotation bearing joint (RB) suspended below said vessel (V) to compensate for vertical motion between a subsea well (W) and a floating vessel (V). The upper marine riser package (10/10A) is sized to be run through a confined opening such as a riser handling spider (HS) and rotary table (RT) and to be suspended and operated below the deck of the vessel (V). The upper marine riser package can be used to eliminate the conventional riser tensioners normally above the platform and can be used in combination with such conventional riser tensioners normally above the platform for deeper and deeper drilling opertion. Two versions of the upper marine riser package (10/10A) ar disclosed, one (10) with an elastomeric bearing type flexible joint (FJ) and the other (10A) with a ball joint.
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BACKGROUND OF THE INVENTION
The present invention relates to apparatus for manufacturing textiles on a textile loom and in particular to a double dent reed which spaces the individual warp ends on the loom and holds them parallel as the reed pushes the filling yarn into place at the fell of the fabric.
As each pick of the filling yarn is inserted through the shed of the warp yarns, the reed pushes the filling yarn against the already woven part of the fabric in an action commonly referred to as beat-up. Many types of cloth such as very fine fabrics, require a large number of warp yarn ends per inch of reed. It is difficult, if not impossible, to arrange the dents to provide a passage space for each warp end. A problem occurs because the warp yarns forming a shed for insertion of the filling yarn to pass, often stick or cling together due to their close proximity to one another. Maintaining the warp ends parallel becomes difficult during shedding and beating-up. This sticking can also result in breakages when the reed moves forward over the warp yarn ends during beat-up. Slubs, knots, and other imperfections in the individual warp yarn ends also tend to catch on the dents due to the narrow spacing therebetween which causes breakage of the warp yarn ends. Warp breaks result in time consuming loom stops or fabric imperfections, both of which are costly in terms of time and production.
The double dent reed arose in an attempt to more evenly space the warp yarn ends and hold them parallel as the reed beats up each pick of the filling yarn. By the use of two rows of dents, the front row beats the filling yarn against the woven fabric and the dents in the back row of dents are arranged to more evenly space the warp ends. Since there are more dents to hold the yarns parallel without a corresponding decrease in spacing distance, the warp ends pass more freely through the reed. In this manner, ends are spaced more evenly without constriction of the passage spaces between dents. Typical of earlier double dent reed constructions are those shown in U.S. Pat. No. 1,146,478, Dutch Pat. No. 2,823,222, and British Pat. No. 8,525.
As shown in U.S. Pat. No. 4,481,980, which is hereby incorporated herein by this reference, a double dent reed typically includes a frame which carries two rows of dents between a plurality of upper support bars and a plurality of lower support bars. Channels, as in double dent reeds available from Sulzer of Switzerland, may be used in place of the support bars in constructing the frame that carries the two rows of dents.
In a double dent reed, each row of dents includes a plurality of wire dents which are spaced apart side by side along the length of the frame. As schematically shown in FIG. 6, the front row R1 of dents d1 is spaced staggered from the gaps G1 between the dents d2 in the back row R2 of dents d2. In a double dent reed available from Sulzer of Switzerland schematically shown in FIG. 6, there is a 1.7 mm open separation space S between the two rows R1, R2 of dents. The warp yarn ends 12 on the loom are guided through the gaps G1, G2 between the dents d1, d2. One side of the frame is clamped to a moving beam, commonly called a slay, on the loom. The slay moves the reed back and forth to produce the beat-up action. The inertial forces on the upper free side of the reed frame are considerable when utilized on high speed loom operations. One side of the reed is commonly referred to as the beat-up side as it faces the fell of the cloth being woven. The wire dents are normally fairly rigid so that they may beat up the filling yarn against the fabric already woven.
While double dent reeds are an improvement, it has been found that considerable resistance to the passing of the warp ends may still be had in the back row of dents due in part to their staggered positioning relative to the gaps between the dents in the front row. This staggered positioning of the dents in the back row, requires the warp yarns to assume a somewhat tortuous path through the reed. This is particularly a problem in the weaving of terry cloth because of the need to keep the pile ends loose so that the loops found in the terry cloth can be properly formed. The pile ends can be caught on the adjacent ground ends, which are under tension, resulting in pulls and other imperfections in the weave of the terry cloth. Moreover, the tortuous path of the yarn ends between the front and back rows of dents is itself a cause of abrasion of the yarn ends and also results in yarn breaks and the accumulation of lint and size between the rows of dents.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, an important object of the present invention is to provide a double dent reed construction for a loom which permits the warp yarn ends to pass more freely through the dent spaces and reduces warp breakages, warp abrasion, and the accumulation of lint in the reed.
Another important object of the present invention is to provide a double dent reed construction for a high speed loom in which the separation space between the trailing edges of the dents in the row of dents on the beat-up side of the reed and leading edges of the dents in the row of dents on the clamping side of the reed, can be increased to reduce the angle of attack between the warp yarn ends and the dents during beat-up.
A further important object of the present invention is to provide a double dent reed construction for a loom which has a first and second row of staggered dents carried in the frame by means of upper and lower baulk mechanisms wherein at least the lower baulk mechanism is configured with a stepped clamping portion.
Still another important object of the present invention is to provide a double dent reed construction for a loom which has a first and second row of staggered dents carried in the frame by means of upper and lower baulk mechanisms wherein at least the lower baulk mechanism is configured as a two-tiered channel with the clamping portion stepped from the upper portion of the lower baulk mechanism.
Yet another important object of the present invention is to provide a double dent reed construction for a loom which has a first and second row of staggered dents carried in the frame by means of upper and lower baulk mechanisms formed as channels and wherein the ends of the dents are held in the channels with epoxy.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the apparatus and method of the present invention can be summarized as follows.
The above objectives are accomplished according to the present invention by means of a reed construction which includes a first row of dents on the beat-up side of the frame and a second row of dents on the warp beam side of the frame. A separation space is disposed between the first and second rows of dents.
The dents of both rows are carried in the frame by means of upper and lower channels. The lower channel is provided with a two-tiered configuration wherein the upper portion has a greater depth than the clamping portion, which nonetheless has adequate structural strength for clamping on the slay of the loom by which the beat-up action is imparted to the reed.
The lengths of the dents in the second row are shorter than the lengths of the dents in the first row and thus do not extend into the clamping portion of the lower channel. Because only one row of dents extends into the clamping portion of the lower support channel in the reed construction of the present invention, a larger separation can be disposed between the two rows of dents than if both rows of dents were to extend into the clamping portion of the lower support channel. Thus, in the present invention, the separation space that exists between the trailing edges of the first row of dents and the leading edges of the second row of dents measures a distance that is increased over that available in the conventional construction of a double dent reed.
Because of this increased separation space available in the reed construction of the present invention, the angle of attack between the dents and the warp yarn ends in the reed construction of the present invention, is reduced over the angle of attack in a conventional double dent reed and offers less resistance to the yarn passage, thereby reducing the abrasion of the warp yarns, reducing the lint build-up between the dents, and increasing efficiency by offering a larger effective opening to the warp yarns.
Because of the stepped configuration of the clamping portion, a shim of 1 mm thickness can be used to protect the clamping portion of the reed from indentations by the socket screws which fix the reed in the slay.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one embodiment of the invention and, together with the description, serve to explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The construction designed to carry out the invention will be hereinafter described, together with other features thereof.
The invention will be more readily understood from a reading of the following specification, which serves to explain the principles of the invention, and by reference to the accompanying drawings forming a part of the specification, wherein an example of the invention is shown and wherein:
FIG. 1 is an elevation illustrating schematically the beat-up of a filling yarn on a textile loom by means of a reed;
FIG. 2 is an elevation of a partial assembly view of a double dent reed construction according to the present invention;
FIG. 3 is a partial, cut away front elevation of a double dent reed construction according to the present invention and shown in relation to the slay of the loom;
FIG. 4 is a sectional view of the double dent reed construction taken in the direction of the arrows 4--4 of FIG. 3;
FIG. 5 is a sectional view taken in the direction of either set of the arrows 5--5 of FIG. 3;
FIG. 6 schematically illustrates from a top sectional view taken in the direction of the arrows 5--5 of FIG. 3, what is meant by the angle of attack between the dents and the warp yarn ends in a prior art reed; and
FIG. 7 schematically illustrates from a top sectional view taken in the direction of the arrows 5--5 of FIG. 3, what is meant by the angle of attack between the dents and the warp yarn ends in a reed construction of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference now will be made in detail to the presently preferred embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents. The same numerals are assigned to the same components throughout the drawings and description.
The invention relates to a reed construction for a loom which beats the filling yarn against the already woven part of the fabric on the loom. As schematically shown in FIG. 1, the loom typically includes a warper beam 10 on which a plurality of warp yarn ends 12 are carried. The warp yarn ends are raised and lowered on the loom by means of harnesses 14 to form a shed 16 in which a filling yarn 18 is inserted.
As shown schematically in FIG. 1, a reed A is carried on a movable slay 20 by means of a clamp 20a on the end of the slay. After the filling yarn 18 is inserted, the slay is moved forward to the full line position and the reed pushes the filling yarn 18 against the fell 22 of the woven part of the fabric 24 previously woven. The woven fabric is then taken up on a cloth roll 26.
A preferred embodiment of the double dent reed of the present invention is shown in FIGS. 2, 3 and 4 and is designated generally by the numeral 28. As shown in FIGS. 2, 3, 5 and 7, reed 28 includes a first plurality of dent wires 30 fixed in a side-by-side arrangement in a first or front row B of dents to define a plurality of dent gaps 32 (FIGS. 2 and 7) therebetween through which the individual warp yarn ends 12 (FIG. 7) pass. The first row B of dents 30 is illustrated on the beat-up side of the reed. The beat-up side of the reed is the side which beats the filling yarn against the already woven part of the fabric 24.
As shown in FIGS. 2, 3, 5 and 7, a second plurality of wire dents 34 is fixed in a side-by-side arrangement in a second or back row C that is disposed behind the first row B of dents 30 such that a separation space 68 (FIGS. 4 and 7) exists between the two rows of dents. As shown in FIGS. 2 and 7, a second plurality of dent gaps 36 is defined between the dents 34 of the second row C. In a preferred embodiment, each gap 32 between adjacent dents 30 is equal in size to each gap 36 between adjacent dents 34. As illustrated, the dents 34 of the second row C are carried about midway between the dents 30 of the first row B in a staggered relation. Thus, a pair of warp yarns 12a (FIG. 7) pass together through gaps 32 in the first row B of dents 30 for beat-up but are evenly spaced in a parallel relationship by means of the staggered dents 34 in the succeeding row C of dents 34 during shedding.
In accordance with the present invention, a double dent reed construction includes a frame for carrying two rows of dents in a fixed spatial relationship. In a preferred embodiment, the dents 30, 34 are formed of stainless steel. The two rows B, C of dents 30, 34 are held in their fixed relationship in the frame by means of an upper baulk mechanism and a lower baulk mechanism disposed opposite the upper baulk mechanism. As shown in FIG. 2, an upper baulk mechanism is designated generally by the letter D and provides a means for holding one set of opposing remote ends 30a, 34a of the first and second rows B, C of dents 30, 34 in a fixed relationship in the reed 28. Similarly, a lower baulk mechanism is designated generally by the letter E and provides a means for holding the opposite remote ends 30b, 34b of the two rows B, C of dents 30, 34 in a fixed relationship in the reed. Thus, the opposed remote ends 30a and 30b of the dents 30 of the front row B and the opposed remote ends 34a and 34b of dents 34 of the back row C are supported in the frame by means of an upper baulk mechanism D and a lower baulk mechanism E. Supporting end frame structure (not shown) at the ends of the reed 28 may be provided as required.
As shown in FIGS. 2, 3, and 4 for example, the upper baulk mechanism D includes an upper channel 38 in the form of a first rigid, elongated longitudinal beam that defines a first elongated longitudinal slot 39 (FIG. 2). Upper channel 38 desirably is formed in a rectangular configuration and has a top wall 40 that is connected between two opposing side walls 41. In a preferred embodiment, the top wall and side walls of the upper channel are formed as a unitary structure made of aluminum. As shown in FIG. 2, the free ends 43 of the side walls 41 define an entrance 42 into the first elongated slot 39 that extends between the two open ends 44 of the upper channel.
As shown in FIG. 2, the first slot 39 of upper channel 38 has a depth that is measured as the perpendicular distance between the two opposed side walls 41. The first slot 39 of upper channel 38 is configured to receive therein, side-by-side, one set of the remote ends 30a of a first row B of dents 30, one set of the remote ends 34a of a second row C of dents 34, and a first rectangular filler bar 45 disposed between these sets of the remote ends 30a, 34a of the first and second rows B, C of dents 30, 34, respectively. The interposed first rectangular filler bar 45 is configured to extend substantially the full length of first slot 39 of upper channel 38. Thus, the upper channel forms a support that carries one set of the remote ends 30a, 34a of the two rows B, C of dents 30, 34.
As shown in FIGS. 2, 3, and 4 for example, the lower baulk mechanism E includes a lower channel 50 in the form of a second rigid, elongated longitudinal beam that defines a second elongated longitudinal slot 51. The lower channel forms a support that carries one set of the remote ends 30b, 34b of the two rows B, C of dents 30, 34, respectively. Lower channel 50 desirably is formed in a two-tiered rectangular configuration and has a bottom wall 52, a front wall 53 that is integral with bottom wall 52, and a tiered back wall 54 that is integral with bottom wall 52 and disposed to oppose front wall 53. In a preferred embodiment, the bottom wall 52, front wall 53 and tiered back wall 54 of the lower channel are formed as a unitary structure made of aluminum. Back wall 54 has an upper back wall 55 connected to a lower back wall 56 by a riser member 57 extending between and perpendicular to both upper back wall 55 and lower back wall 56. As shown in FIG. 4, upper back wall 55 is disposed to oppose the upper portion 58 of front wall 53. Thus, the lower channel 50 has an upper portion defined by the upper portion 58 of front wall 53, a riser member 57, and upper back wall 55.
As shown in FIGS. 2, 3, and 4, the second slot 51 of lower channel 50 is tiered in an upper portion 59 (FIG. 2) and a lower portion 60 (FIG. 2). The upper portion 59 of tiered second slot 51 has a depth that is measured as the perpendicular distance between the upper portion 58 of front wall 53 and the opposed upper back wall 55. As shown in FIGS. 3 and 4, the measurements of depth dimensions 83, 84, 85 (FIG. 4) are taken in a direction transverse to the direction in which the dents 30 and dents 34 are disposed side-by-side (FIG. 3). The upper portion 59 of second slot 51 of lower channel 50 is configured to receive therein, side-by-side, the first row B of dents 30, one set of the remote ends 34b of a second row C of dents 34, and a first double flat-sided filler rod 61 disposed between the first and second rows B, C of dents 30, 34, respectively. The interposed first double flat-sided filler rod 61 is configured to extend substantially the full length of lower channel 50. This upper portion 59 of the lower channel 50 is the so-called dent-receiving portion 59 of lower channel 50 because it receives one set of the remote ends 34b of one row C of dents 34 and the other row B of dents 30 passes through this upper portion 59 of lower channel 50. The free end 62 of the upper portion 58 of the front wall 53 and the free end 63 of the upper back wall 55 define an entrance 64 into the upper portion 59 of second slot 51 that extends between the two open ends 65 of the lower channel.
Integral with the upper portion of the lower channel is a clamping portion of the lower channel. The clamping portion is configured so that the frame can be clamped on the slay 20 of the loom for movement during beat-up of a filling yarn on the loom. As shown in FIGS. 2, 3, and 4, the clamping portion of lower channel 50 includes lower back wall 56, bottom wall 52, and a lower portion 66 of front wall 53. Bottom wall 52 connects the lower portion 66 of front wall 53 to lower back wall 56. Because riser member 57 steps away from upper back wall 55 to connect to lower back wall 56, the clamping portion of lower channel 50 is said to be stepped from the upper portion of lower channel 50, and lower channel 50 is said to be a stepped lower channel 50.
The clamping or stepped portion 60 of second slot 51 of lower channel 50 is defined by lower back wall 56, bottom wall 52, and the lower portion 66 of front wall 53. The clamping portion 60 of second slot 51 of lower channel 50 is configured to receive therein, side-by-side, one set of the remote ends 30b of one row B of dents 30 and a second rectangular filler bar 67 disposed between one of either the leading edges 75 or trailing edges 76 of the dents 30 in the row B of dents 30 and one of either the lower back wall 56 or the lower portion 66 of front wall 53. As shown in FIG. 4, the interposed second rectangular filler bar 67 is configured to extend substantially the full length of the clamping portion 60 of second slot 51 of lower channel 50 and extends into the upper portion 59 of second slot 51 of lower channel 50.
The clamping portion 60 of tiered second slot 51 has a depth that is measured as the perpendicular distance between the lower portion 66 of front wall 53 and the opposed lower back wall 56. The upper portion 59 (a.k.a. dent receiving portion) of the tiered second slot 51 has a depth that is measured as the perpendicular distance between the upper portion 58 of front wall 53 and the opposed upper back wall 55. The upper portion 59 (a.k.a. dent receiving portion) of the tiered second slot 51 has a greater depth than the lower portion 60 or (a.k.a. clamping portion) of the tiered second slot 51, hence the stepped configuration. As shown in FIG. 3, this stepped configuration of the clamping portion of reed 28 enables reed 28 to be used in the bracket of a standard loom, yet provides the advantages of an increased separation space 68 between the two rows B, C of dents 30, 34.
As shown in FIGS. 2, 3, 4, and 5, the clamping portion 60 of second slot 51 of lower channel 50 is stepped from and integral with the upper portion 59 and is configured to receive one of the first and second rows of dents. The upper portion of the lower channel has a depth that is at least as great as the sum of the depths of the first and second rows B, C of dents 30, 34 and the separation space 68 (FIGS. 4 and 7) that is disposed between the first and second rows B, C of dents 30, 34. The stepped clamping portion of lower channel 50 is configured with a depth that is smaller than the depth of the upper portion of lower channel 50 by at least an amount equal to the depth of one of the first and second rows B, C of dents 30, 34. In the illustration of FIG. 2, the first row B of dents 30 is on the beat-up side of the reed, and the second row C of dents 34 is on the back side of the reed. Accordingly, in the embodiment shown, the stepped clamping portion of the lower channel 50 has a depth that is smaller than the upper portion of the lower channel by a distance equal to at least the depth of the second row C of dents 34.
As shown in FIG. 3, the reed 28 is fixed in the slay 20 (dashed line) with hexagon socket screws 69 threaded through a bracket 70 at regular intervals over its entire length. As shown in FIG. 3 for example, the stepped clamping portion of lower channel 50 is configured with a depth that is smaller than the depth of the dent-receiving portion by at least the depth of a shim 71 and the depth of one of the first and second rows B, C of dents 30, 34. When the reed is installed into the clamping bracket 70 of the slay 20, a thin one millimeter shim 71 for example can be disposed against the exterior surface 72 of the stepped lower clamping portion of the lower channel so that when the fastening screws 69 are tightened, the ends 73 of the screws 69 will press against the shim 71 rather than the exterior surface 72 of the stepped portion of lower channel 50 of the frame of the reed. This prevents indentations from being formed in the stepped portion of the lower channel. The ability to provide the lower channel with a reduced depth enables this protective shim to be used. In a preferred embodiment, the shim used with the clamping portion is formed of stainless steel.
As shown in FIGS. 4 and 7, each of the dents 30 or 34 defines a leading edge 75 and a trailing edge 76 facing opposite to the leading edge. Each of the trailing edges 76 is disposed toward the stepped clamping portion and away from the beat-up side of the reed when fixed into place in the upper and lower channels 38, 50.
As shown in FIGS. 6 and 7, the tortuous path of the warp ends 12 through the gaps G1, G2 (FIG. 6); 32, 36 (FIG. 7) between front and back rows R1, R2 (FIG. 6); B, C (FIG. 7) of dents d1, d2 (FIG. 6); 30, 34 (FIG. 7) can be characterized by the angle of attack α (FIG. 6), β (FIG. 7) that exists between the warp ends 12 and the dent as the dent approaches and then moves past the warp ends during each stroke of the beat-up motion of the reed. The larger this angle of attack, the more abrasion that is caused on the warp yarns. The larger this angle of attack, the more likely that the adjacent warp yarns will stick and or entangle during the stroke of the reed. For purposes of comparison, FIG. 6 shows the attack angle α in a conventional double dent reed and FIG. 7 shows the attack angle β in a preferred embodiment of the double dent reed of the present invention. As illustrated by comparison of the attack angle α in the conventional double dent construction of FIG. 6 with the angle of attack β of the reed construction of the present invention of FIG. 7, the increased separation space 68 between the front and back rows of dents in the reed of the present invention, reduces the attack angle β of the warp yarns relative to the path of movement taken by the dents, as the yarn ends enter the front row B of dents 30 from the back row C of dents 34. A similar reduction in attack angle would be encountered when the reed moves in the opposite direction (to the dashed line position of slay in FIG. 1) as the warp yarns enter the back row C of dents 34 from the front row B of dents 30. The smaller this attack angle, the less abrasion that is caused on the warp yarns. Reducing this abrasion results in a reduction in the accumulation of lint and size between the rows of dents. The smaller this attack angle, the less likely that the warp yarns will become entangled, pulled or broken.
Thus, the stepped lower channel construction of the present invention permits an increase in the separation space 68 between the two rows B, C of dents 30, 34 over that obtainable in conventional reeds, thereby reducing the angle of attack so that less resistance is presented to the passages of the knots, slubs, and the warp yarn ends through the dent gaps 32, 36 and the adjacent warp ends are less likely to stick to one another. This also reduces the accumulation of lint which often occurs in the dent gaps of more closely spaced dent row constructions of double dent reeds.
The double dent reed of the present invention is particularly useful for weaving terry cloth. In a loom that is set up to weave terry cloth, a double dent reed is used to separate the pile ends (from which the loops in the terry cloth are formed) from the ground ends (which are maintained under tension on the loom) as this arrangement diminishes the likelihood that the ground ends will pull the pile ends during beat up and cause imperfections in the cloth. By reducing the angle of attack, the reed of the present invention further diminishes the likelihood that the ground ends will pull the pile ends during the weaving of the terry cloth.
While the dimensions can be varied according to the type of reed and loom that is desired, a preferred embodiment of a 70% air-space reed 28 is constructed with the following dimensions. Upper channel 38 has a height (80, FIG. 4) of 12.7 mm and lower channel 50 has a height (81, FIG. 4) of 25 mm with lower back wall (82, FIG. 4) having a height of 18 mm and upper back wall 55 having a height of 7 mm. The depth (83, FIG. 4) of upper channel 38 is 12.7 mm. The depth (84, FIG. 4) of the upper portion of lower channel 50 is 10.5 mm, and the depth (85, FIG. 4) of the clamping portion of lower channel 50 is 8 mm. As shown in FIG. 5, dents 30, 34 are formed with a thickness 49 of 0.022 inches and a depth 48 of 0.090 inches (2.3 mm). The separation space 68 between the trailing edges 76 of the front row B of dents 30 and the leading edges 75 of the back row C of dents 34 is 0.118 inches (3.1 mm). As shown in FIG. 5, the diameter of the wire 47 (described below) is 0.013 inches, and there are six windings of the wire 47 between the dents 30 in the front row B and six windings of the wire 47 between the dents 34 in the back row C, thus providing three windings between adjacent dents 30, 34 alternating from the front and the back rows B, C. The side-by-side gap 32 between adjacent dents, whether between adjacent dents 30 in row B or between adjacent dents 34 in row C, is 0.078 inches. The total length of each dent 30 in the front row B is about 96 mm, and the total length of each dent 34 in the back row C is about 78 mm. The working length of each dent 30 or 34 is about 52 mm. The overall height (86, FIG. 4) of the reed 28 is about 102 mm.
In a preferred embodiment shown FIGS. 3, 4, and 5, the upper baulk mechanism D includes a first double flat-sided rod 90 disposed between the first and second rows B, C of dents 30, 34 and at the entrance 42 of first slot 39. The lower baulk mechanism E further includes a second double flat-sided rod 90 disposed between the first and second rows B, C of dents 30, 34 and above the second slot 51 near the entrance 64 of the second slot 51. Each of the upper baulk mechanism and the lower baulk mechanism also includes a first elongated tying member 91. Each first tying member 91 has a flat side and a curved side disposed opposite to the flat side. Each first tying member 91 is disposed at the respective entrance 42, 64 of the respective slot 39, 51 of the respective upper channel 38 or lower channel 50 and with the flat side of the first tying member disposed against the leading edges 75 of the dents 30 in the first row B of dents 30. Each of the upper baulk mechanism D and the lower baulk mechanism E also includes a second elongated tying member 92. Each second tying member 92 has a flat side and a curved side disposed opposite to the flat side. Each second tying member 92 is disposed at the respective entrance 42, 64 of the respective slot 39, 51 of the respective upper channel 38 or lower channel 50 and with the flat side of the second tying member 92 disposed against the trailing edges 76 of the dents 34 in the second row C of dents 34. In a preferred embodiment, the tying members 91, 92, the double flat-sided rods 90, and the rectangular filler bars 45, 67 of the upper and lower baulk mechanisms D, E are formed of carbon steel.
As shown in FIGS. 2, 3, 4, and 5, each of the upper and lower baulk mechanisms D, E includes a wire 47 that is wound successively around the lengths of at least the first tying member 91, the double flat-sided rod 90, and the second tying member 92. As shown in FIG. 5 for example, the same number of windings of wire 47 is disposed between adjacent dents 30, 30 or 34, 34 in each of the first and second rows B, C of dents. Depending upon the side-by-side gaps 32 or 36 that are desired between the dents in each row of dents, the number of windings of the wire 47 between adjacent dents in a row and the diameter of the wire can be selected accordingly. In a preferred embodiment, the wire 47 is formed of stainless steel.
After the two rows B, C of dents 30, 34 are wired to the upper set of flat-sided rods 90, 91, 92 and the two rows B, C of dents 30, 34 are wired to the lower set of flat-sided rods 90, 91, 92, the opposed remote ends 30a, 30b or 34a, 34b of the dents 30, 34 may be affixed respectively within the upper or lower channels 38, 50 by any suitable means such as by bonding with a suitable thermoplastic adhesive such as disclosed in U.S. Pat. No. 3,189,056, which is incorporated herein by this reference. The first slot 39 of upper channel 38 and the second slot 51 of lower channel 50 are prepared by inserting the respective filler bars 45, 67 and pouring thermoplastic adhesive 95 (FIG. 2) such as epoxy into the first slot 39 of the upper channel and into both tiers of the second slot 51 of the lower channel. The evenly matched remote ends 30a, 34a of the two rows B, C of dents 30, 34 are inserted into the upper channel containing the epoxy. As shown in FIG. 4, insertion of the dents 30, 34 displaces some of the epoxy from the first slot, and the excess epoxy 96 that is displaced may be trimmed away. Similarly, the unevenly matched remote ends 30b, 34b of the two rows B, C of dents 30, 34 and flat-sided filler rod 61 are inserted into the lower channel, and the displaced epoxy 96 may be trimmed away. As shown partially broken away in the view of FIG. 3, the epoxy 97 is then allowed to harden to fix the dents 30, 34 in the frame of the reed.
While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.
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A reed (28) for a loom includes a frame with upper and lower baulk mechanisms (D, E) that carry a front row (B) of dents (30) on the beat-up side of the frame and a back row (C) of dents (34) staggered in alignment with dents (30). Lower baulk mechanism (E) includes a stepped clamping portion which is reduced in depth compared to the depth of the upper portion of the lower baulk mechanism (E) such that dents (34) are shorter in height in the lower baulk mechanism (E) than dents (30). This renders one of the rows (C) of dents (34) able to be disposed farther from the other row (B) of dents (30) than if they were to extend into the clamping portion of the lower baulk mechanism (E) the same amount as dents (30). In this way, the angle of attack between the dents and the warp yarn ends is reduced and offers less resistance to the yarn passage, reducing abrasion of the warp yarns, reducing the lint buildup between the dents, and increasing efficiency by reducing the incidence of friction between adjacent warp yarns.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to ink-jet technology and, more particularly to a heated printing zone vacuum platen.
[0003] 2. Description of the Related Art
[0004] The art of ink-jet technology is relatively well developed. Commercial products such as computer printers, graphics plotters, copiers, and facsimile machines employ inkjet technology for producing hard copy. The basics of this technology are disclosed, for example, in various articles in the Hewlett - Packard Journal , Vol. 36, No. 5 (May 1985), Vol. 39, No. 4 (August 1988), Vol. 39, No. 5 (October 1988), Vol. 43, No. 4 (August 1992), Vol. 43, No. 6 (December 1992) and Vol. 45, No. 1 (February 1994) editions. Ink-jet devices are also described by W. I. Lloyd and H. T. Taub in OUTPUT HARDCOPY [sic] DEVICES, chapter 13 (Ed. R. C. Durbeck and S. Sherr, Academic Press, San Diego, 1988). As providing background information, the foregoing documents are incorporated herein by reference.
[0005] It is known to use a vacuum induced force to adhere a sheet of flexible material to a surface, for example, for holding a sheet of print media temporarily to a platen. [Hereinafter, “vacuum induced force” is also referred to as “vacuum induced flow,” “vacuum flow,” or more simply as just “vacuum” or “suction,” as best fits the context.] Such vacuum holddown systems are a relatively common, economical technology to implement commercially and can improve hard copy apparatus throughput specifications. For example, it is known to provide a rotating drum with holes through the surface wherein a vacuum through the drum cylinder provides a suction force at the holes in the drum surface (see e.g., U.S. Pat. No. 4,237,466 (Scranton)). [The term “drum” as used hereinafter is intended to be synonymous with any curvilinear implementation incorporating the present invention; while the term “platen” can be defined as a flat holding surface, in hard copy technology it is also used for curvilinear surfaces, such as the ubiquitous typewriter rubber roller; thus, for the purposes of the present application, “platen” is used generically for any shape paper holddown surface used in a hard copy apparatus.] Permeable belts traversing a vacuum inducing support have been similarly employed (see eg., Scranton and U.S. patent application Ser. No. 09/163,098 by Rasmussen et al. for a BELT DRIVEN MEDIA HANDLING SYSTEM WITH FEEDBACK CONTROL FOR IMPROVING MEDIA ADVANCE ACCURACY (assigned to the common assignee of the present invention and incorporated herein by reference)).
[0006] Generally in a hard copy apparatus implementation, the vacuum device is used either to support cut-sheet print media during transport to a printing station of a hard copy apparatus, to hold the sheet media at the printing station while images are formed (known as the “printing zone”), or both. [In order to simplify discussion, the term “paper” is used hereinafter to refer to all types of print media and the tern “printer” to refer to all types of hard copy apparatus; no limitation on the scope of the invention is intended nor should any be implied.]
[0007] Typically thermal ink-jet inks are water-based and when deposited on wood-based is papers, they are absorbed into the cellulose fibers, causing the fibers to swell. As the cellulose fibers swell, they generate localized expansions, causing the paper cockle. Not only does this create a finished hard copy product that may be objectionable to the end-user, cockle growth can cause actual degradation of ink dot printing quality itself due to uncontrolled pen-to-paper spacing which may even, in turn, lead to pen printhead-to-paper contact as the cockle waves move a region of the paper upwardly.
[0008] Moreover, most commercial ink-jet printers allow the paper to exit the printing zone on a flat platen or into a substantially flat output tray while the ink is drying. A flat platen with no post-printing holddown mechanism allows cockle to expand, generally creating larger waves in the sheet of paper.
[0009] Furthermore, in order to produce high quality color copy, e.g., photo-quality printing, ink flux is increased to produce vivid color saturation. This flux increase further exacerbates the paper cockle problem.
[0010] Still further, ink-jet printhead size is increasing to increase throughput. As the print zone length increases, ink bleed effects and the paper cockle problem are again enlarged or intensified.
[0011] Several solutions to these problems have been developed. U.S. Pat. No. 4,329,295 (Medin et al.) for a PRINT ZONE HEATER SCREEN FOR THERMAL INK-JET PRINTER, U.S. Pat. No. 5,461,408 (Giles et al.) for a DUAL FEED PAPER PATH FOR INK-JET PRINTER, U.S. Pat. No. 5,399,039 (Giles et al.) for an INK-JET PRINTER WITH PRECISE PRINT ZONE MEDIA CONTROL, U.S. Pat. No. 5,420,621 (Richtsmeier et al.) for a DOUBLE STAR WHEEL FOR POST-PRINTING MEDIA CONTROL IN INKJET PRINTING, and Des. Pat. No. 358,417 (Medin et al.) (each is assigned to the common assignee of the present invention and incorporated herein by reference) exemplify various techniques for a hard copy apparatus using conventional electromechanical paper feed systems. U.S. Pat. No. 5,742,315 (Szlucha et al.) shows a SEGMENTED FLEXIBLE HEATER FOR DRYING A PRINTED IMAGE. A segmented flexible beater is disposed adjacently to a paper path for heating a recording medium before and during printing.
[0012] There remains a need for print zone and post-print zone paper path transport mechanisms that assist in reducing the expanding paper cockle problem. One solution is to hold the paper to a platen with a vacuum force during printing. However, it has been found that with vacuum holding creates a higher frequency, or sharper looking, cockle wave in the paper. The geometric complexities of designing a vacuum transport type apparatus compounded by the heating of the transported flexible material creates a need for unproved heat distribution mechanisms. In ink-jet printing applications, there is a need for vacuum holddown paper path systems that assist in reducing or substantially eliminating paper cockle.
SUMMARY OF THE INVENTION
[0013] In a basic aspect, the present invention provides a print media vacuum holddown device, including: supporting mechanisms for supporting a print media transport belt, having a first pattern of vacuum passages therethrough for distributing vacuum across a support surface, the support surface having a second pattern of surface mechanisms for containing heating mechanisms interspersed with the first pattern of vacuum passages; and heating mechanisms for generating heat for transmission to the belt, wherein the heating mechanisms are inset within the surface mechanisms such that the heating mechanisms are substantially surrounded by a gap from the supporting mechanisms wherein the supporting mechanisms is insulated from heat emitted by the heating mechanisms.
[0014] In another basic aspect, the present invention provides a hard copy apparatus, including: a printing station; proximate the printing station, writing mechanisms for printing on print media; transport mechanisms for selectively transporting the print media into and out of the printing station; and mounted proximate the printing station adjacently to the writing mechanisms, vacuum platen mechanisms for supporting print media transported through the printing station, the platen mechanisms including supporting mechanisms for supporting a print media transport belt, having a first pattern of vacuum ports therethrough and a support surface having a second pattern of surface channels interspersed with the first pattern of vacuum ports, and heating mechanisms for transmitting heat to the belt, inset within the surface channels such that the heating mechanisms are substantially surrounded by a gap from the supporting mechanisms wherein the supporting mechanisms is insulated from beat emitted by the heating mechanisms.
[0015] Another basic aspect of the present invention is a method for heating a print medium in a printing zone of a hard copy apparatus having a vacuum inducing subsystem, including the steps of: providing a vacuum holddown and positioning the holddown in the printing zone; interspersing electrical heating elements with vacuum ports across a surface of the holddown such that the heating elements are isolated from the surface by a gap; and transporting the print medium through the printing zone on a belt in superjacent contact with the platen at least in the printing zone while reducing cockle from ink droplets deposited on the medium and heat loss via the vacuum subsystem.
[0016] In another basic aspect, the present invention provides a method for heating on a print medium in a printing zone of a hard copy apparatus having a vacuum inducing subsystem, including the steps of: positioning a vacuum holddown having an electrically resistive, heat emitting surface in the printing zone, the surface have passageways therethrough coupled to the vacuum inducing system; and transporting the print medium through the printing zone on a belt in superjacent direct contact with the surface at least in the printing zone, using the surface for reducing cockle from ink droplets deposited on the medium while reducing heat loss via the vacuum subsystem.
[0017] Some advantages of the present invention are:
[0018] it reduces the spread of thermal mass and therefore the attendant amount of energy and time to bring a heater up to operating temperature;
[0019] it reduces the loss of thermal energy through the vacuum platen structure itself due to the intrinsic air flow design;
[0020] it substantially eliminates thermal mass induced lang and resultant non-uniform temperature profiles in the printing zone;
[0021] it reduces spreading of undesirable heat to adjacent parts of the hard copy apparatus and vacuum subsystems;
[0022] it uses materials conducive to faster rise time to operating temperatures;
[0023] it provides a vacuum transport for ink-jet paper transport which will reduce cockling;
[0024] it reduces or substantially eliminates thermal expansion induced problems; and
[0025] it limits heat loss through the vacuum subsystem and the concomitant need for is more powerful and efficient heating subsystems, thus reducing cost of manufacture.
[0026] The foregoing summary and list of advantages is not intended by the inventor to be an inclusive list of all the aspects, objects, advantages and features of the present invention nor should any limitation on the scope of the invention be implied therefrom. This Summary is provided in accordance with the mandate of 37 C.F.R. 1.73 and M.P.E.P. 608.01(d) merely to apprize the public, and more especially those interested in the particular art to which the invention relates, of the nature of the invention in order to be of assistance in aiding ready understanding of the patent in future searches.
[0027] Other objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description and the accompanying drawings, in which like reference designations represent like features throughout the figures.
DESCRIPTION OF THE DRAWINGS
[0028] [0028]FIG. 1 is a schematic depiction of an ink-jet hard copy apparatus 10 in accordance with the present invention.
[0029] [0029]FIG. 2 is a detail segment schematic of the platen in accordance with the present invention shown in FIG. 1.
[0030] [0030]FIG. 3 is a schematic depiction in cross-section of the present invention as shown in FIG. 2.
[0031] [0031]FIG. 3A is a close-up detail from FIG. 3.
[0032] [0032]FIG. 3B is an alternative embodiment of the present invention as shown in FIGS. 2 and 3.
[0033] [0033]FIG. 4 is an alternative embodiment schematic depiction in cross-section of the present invention.
[0034] [0034]FIG. 5 is an alternative embodiment schematic of the present invention illustrated in a cross-section perspective view.
[0035] The drawings referred to in this description should be understood as not being drawn to scale except if specifically noted.
DETAILED DESCRIPTION OF THE INVENTION
[0036] Reference is made now in detail to a specific embodiment of the present invention, which illustrates the best mode presently contemplated by the inventors for practicing the invention. Alternative embodiments are also briefly described as applicable.
[0037] [0037]FIG. 1 is a schematic depiction of an ink-jet hard copy apparatus 10 in accordance with the present invention. A writing instrument 12 is provided with printhead 14 having drop generators including nozzles for ejecting ink droplets onto an adjacently positioned print medium, e.g., a sheet of paper 16 , in the apparatus' printing zone 34 . [The word “paper is used hereinafter for convenience as a generic term for all print media; the implementation shown is for convenience in explaining the present invention and no limitation on the scope of the invention is intended by the inventors nor should any be implied.] An endless-loop belt 32 is one type of known manner printing zone input-output paper transport. A motor 33 having a drive shaft 30 is used to drive a gear train 35 coupled to a belt pulley 38 mounted on an fixed axle 39 . A biased idler wheel 40 provides appropriate tensioning of the belt 32 . The belt rides over a platen 36 in the print zone 34 ; the platen is described in detail hereinafter, but is associated with a known manner vacuum induction system 37 , The paper sheet 16 is picked from an input supply (not shown) and its leading edge 54 is delivered to a guide 50 , 52 where a pinch wheel 42 in contact with the belt 32 takes over and acts to transport the paper sheet 16 through the printing zone 34 (the paper path is represented by arrow 31 ). Downstream of the printing zone 34 , an output roller 44 in contact with the belt 32 receives the leading edge 54 of the paper sheet 16 and continues the paper transport until the trailing edge 55 of the now printed page is released.
[0038] [0038]FIG. 2 illustrates the details of the vacuum platen 36 device of the hard copy apparatus 10 . [It is also contemplated that the construct of the present invention be adapted for use as a vacuum transport subsystem or other vacuum holddown such as might be used for picking a sheet of paper and moving the sheet to the printing zone, providing an additional advantage of preheating the sheet before depositing ink drops, while depositing ink, and post-printing. In order to simplify the detailed description, the word “platen” is used generically; no limitation on the scope of the invention is intended nor should any be implied.] A vacuum manifold 201 is fabricated of a thermally non-conductive material. A plurality of vacuum passageways, or ports, 203 is distributed across the platen surface 204 such that a vacuum will draw down through the ports—represented by arrows labeled “Fv.” Some thermally nonconductive materials suitable for employment in the present invention are thermoset or thermoplastic materials having a low coefficient of thermal expansion, for example, glass-filled polycarbonate, LCP, polyetherimide. The geometric shape, thickness, and material combination can be tailored to a specific implementation.
[0039] Interspersed with the pattern of vacuum ports 203 is a set of platen surface channels 205 . Inlaid within each of the channels is a strip heater 207 (other patterns and shapes may be employed in accordance with the present invention). The heaters 207 are connected to a power source (not shown), such as via or on the hard copy apparatus controller 62 (FIG. 1) in any convenient known manner.
[0040] The use of known resistor trace technology is advantageous in that resistance and therefore heat generated can be predetermined by varying the thickness of the trace.
[0041] As will be apparent to a person skilled in the art, the specific implementation of the structure just described will be related to the hard copy apparatus design and performance specifications; e.g., a platen 36 for a desktop computer peripheral printer will differ from a fax machine or a large engineering drawing plotter. Therefore specific shapes and dimensions for the platen and each sub-component of the platen will vary widely.
[0042] An important aspect of the present invention is that an air gap 209 is provided between the heaters 207 and the side and end walls and the floor of each associated surface channel 205 . Turning also to FIG. 3, a set of standoffs 301 is provided in the floor of each channel 205 for mounting the heaters 207 such that the air gap 209 surrounds each heater 207 , substantially isolating it from the vacuum manifold 201 .
[0043] In a first embodiment the heaters 207 are fabricated as a thick film 303 on a stainless steel or ceramic material substrate as illustrated in FIG. 3A. Generally, a thick film 303 resistive layer, or conductor, 309 can be formed using resistor paste commercially available from Electro-Science Laboratories, Inc., King of Prussia, Pa.; other processes or thick film heating devices known in the art can also be employed. Tape processing methods are alternatively used to tick film techniques for application on a substrate.
[0044] Superjacent the stainless steel substrate 305 is a layer of an electrical insulator 307 , the conductor 309 , and a low abrasive surface insulator 311 . It has been found that the use of a glass coating surface insulator 311 provides a wear resistant, low coefficient of friction layer between the heater 207 and the belt 32 (FIG. 1) as it traverses the platen 36 . The thickness of the insulator 311 is chosen based on the specific implementation such that abrasion of the belt 32 is minimized.
[0045] Merely to provide some idea as to appropriate dimensions, in an exemplary test bed for an ink-jet desktop computer printer, the heater 207 was formed to have a stainless steel substrate approximately one millimeter thick and three millimeters wide; the triple layer thin film was approximately seventy-five to ninety micrometers thick; the vacuum ports 203 had a diameter in the range of about 0.1 to 3.0 millimeters; and a 50% porosity flexible belt 32 having a thickness in the range of approximately 0.003-0.007 inch thick sized for A-size and B-size paper was successfully operated.
[0046] [0046]FIG. 3B is an alternative to the embodiment of FIG. 3. In some applications, it may be advantageous to partially reduce the amount of heat transferred from the heater 207 to the over-riding belt 32 (FIG. 1). It has been found that the same heater structure can be inverted so that the heat from the thick film heater 303 laminate dissipates uniformly through the stainless steel 305 . When appropriately coated or polished, the top surface 313 provides a suitable low friction contact with the adjacent belt 32 .
[0047] [0047]FIG. 4 demonstrates an alternative embodiment employing strip heaters 207 ′ in channels 205 . A heater casing 401 is formed of a thermoset plastic. A Nichrome wire 403 is embedded in the plastic and connected to the power source. In a similar test bed to the aforementioned, a three millimeter square heater 207 ′ was successfully employed.
[0048] [0048]FIG. 5 is an alternative embodiment of a platen 36 ′ for the present invention. A one piece heater 501 having a plurality of apertures 503 is constructed of stainless steel. A base plate 505 is formed of a thermoplastic or thermoset material having a plurality of apertured pillars 506 extending into the apertures 503 of the heater 501 and forming a vacuum Fv passageway 507 . A gasket 509 , such as of silicone foam, is layered between the heater 501 and the base plate 505 . In the geometric complexity of forming an efficient heater-platen for ink-jet uses, this alternative offers a simplicity of construction. Note also that again, either the heater 501 bottom surface 501 ′ or the base plate 505 top surface 505 ′ may be employed as the non-abrasive contact surface with the belt 32 (FIG. 1) with minor modifications to the construct to ensure appropriate vacuum Fv flow.
[0049] The foregoing description of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in this art. Similarly, any process steps described might be interchangeable with other steps in order to achieve the same result. The embodiment was chosen and described in order to best explain the principles of the invention and its best mode practical application to thereby enable others skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents. Reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather means “one or more.” Moreover, no element, component, nor method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the following claims. No claim element herein is to be construed under the provisions of 35 U.S.C. Sec. 112, sixth paragraph, unless the element is expressly recited using the phrase: “means for . . . . ”
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Predetermined geometric constructs reduce heat loss in a vacuum platen and assist in the reduction of paper cockle in ink-jet printing. A vacuum platen for supporting media during printing is provided with a plurality of heating elements and surfaces interspersed with vacuum ports. The heater elements are laid into surface channels of the platen such that an insulative gap separates the heaters from the main platen support structure. In an alternative embodiment, an insulative gasket is provided for the gap.
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TECHNICAL FIELD
The present invention relates to luggage and, more particularly, to a garment bag provided with a detachable wheel and handle assembly for rolling the garment bag.
BACKGROUND OF THE INVENTION
Originally, luggage consisted of a suitcase or duffel bag and perhaps a small "travel bag". These structures allowed many items to be stored in one portable structure.
However, both suitcases and duffel bags suffer from the fact that they are basically large receptacles into which clothing is dumped. Because of their size and shape, certain clothes, especially formal clothes such as suits and dresses, are not easily transported in a suitcase or duffel bag. Suits and dresses placed in a suitcase will almost invariably be wrinkled by both the folding of the clothes to fit within the suitcase and by the shifting of clothes within the suitcase. Travelers must then spend time and money pressing these clothes to remove the wrinkles.
To overcome this problem, garment bags were developed. Garment bags are elongate soft-sided bags. A hook extending from the top of the bag allows the bag to be hung. Suits, shirts and dresses are placed inside the bag and hung from hangers that are affixed to the top of the bag. The clothes hang freely within the elongate garment bag, and therefore are not wrinkled. The garment bag is narrow in width to preclude the clothes from shifting within the bag during transport.
Of course, easy portability is a primary concern for any piece of luggage. However, garment bags are long, which makes it inconvenient to carry them by holding the top of the bag. To enhance portability, garment bags can be and usually are folded in half lengthwise, and carried using a handle that extends upward from the garment bag when it is folded. The clothes hanging within the garment bag are also folded lengthwise when the garment bag is folded. Experience has shown that this one fold does not cause significant wrinkling of the garments.
Garment bags have become standard luggage for many travelers, especially business travelers, because they reduce the extent to which clothes become wrinkled during transport. Indeed, the conventional garment bag has evolved into more than just a suit or dress holder. Garment bags today have pockets for shoes, toiletries and other foldable clothes. For many business travelers, the garment bag has entirely replaced the suitcase.
The broadened utility of garment bags has significantly increased the weight of the typical packed garment bag. Garment bag weights have increased in weight as items other than hanging clothes are stored in the garment bag. However, methods for transporting the increased weights now associated with garment bags have not improved in conjunction with the new utilities of the bag. Garment bags are still transported by a handle or a shoulder strap extending from the top of the folded garment bag. For travelers walking a long way, or for elderly or handicapped travelers, carrying a heavy garment bag is an onerous task.
Putting wheels on suitcases is known in the art as a means for improving the portability of the luggage. However, because of their soft, flexible nature, most garment bags are poor candidates for wheeled transport. If a soft, flexible garment bag is strapped onto a wheeled carrier, the bag sags or folds. When the sagging or folded bag is strapped onto the wheeled assembly, the clothes inside the bag are wrinkled and folded.
Accordingly, a need yet exists for easily transportable luggage for transporting formal garments without wrinkling the garments.
SUMMARY OF THE INVENTION
The present invention solves the above-identified problems in the art by providing a garment bag that is transportable on wheels.
Briefly described, the present invention is a wheeled assembly that is removably attachable to a garment bag. The wheeled assembly has a retractable handle that telescopes upward so that a user can pull the garment bag, and the garment bag rolls on two wheels depending from the wheeled assembly. The wheeled assembly acts like a dolly in carrying the garment bag.
More particularly described, the garment bag of the present invention has U-shaped stiffeners positioned along the top and bottom panels. When the garment bag is folded in half, these stiffeners provide structural rigidity that permits the garment bag to stand upright.
The wheeled assembly is detachably affixed to the front lower portion of the garment bag by a zipper. Two wheels depend from the wheeled assembly, protruding slightly below the bottom panel of the garment bag. When the retractable handle is extended and the user pulls the garment bag behind them, the garment bag rolls on the wheels.
The wheeled assembly can readily be removed from the garment bag by unfastening the zipper. Thus, if the user wants to carry the garment bag and avoid the weight associated with the wheeled assembly, the wheeled assembly is simply removed. Additionally, a pocket assembly is provided. The pocket assembly may be zippered to the garment bag in place of the wheeled assembly if the traveler wants to carry the garment bag. The pocket assembly provides additional storage space.
Further, the garment bag retains a narrow profile, regardless of whether the wheeled assembly or the pocket assembly is attached. This feature is critical to airline travel, allowing the rolling garment bag of the present invention to be stored in the overhead carry bin of an airplane.
The rolling garment bag has the flexibility and structure required for carrying formal garments. However, enough structural rigidity is supplied so that the garment bag may be wheeled.
Accordingly, it is an object of the present invention to provide an improved garment bag.
It is a further object of the present invention to provide a garment bag that may be transported by rolling the garment bag.
It is a further object of the present invention to provide a garment bag that has a detachable wheeled assembly that may be affixed to the garment bag if the user wants to transport the garment bag on wheels, and that may be removed if the user wants to carry the garment bag and avoid the weight associated with the wheeled assembly.
It is a further object of the present invention to provide a garment bag to which a pocket assembly may be attached when the wheeled assembly is not attached to the garment bag.
Other objects features and advantages of the present invention will become apparent upon review of the following detailed description of embodiments of the present invention when taken in conjunction with the drawings and appended claims.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of the preferred embodiment of the present invention, with the rolling garment bag opened.
FIG. 2 is a perspective view of the side wall and top panel of the preferred embodiment of the present invention.
FIG. 3 is a perspective view of the preferred embodiment of the rolling garment bag ready for transport.
FIG. 4 is a rear view of the wheeled assembly.
FIG. 5 is a frontal view of the garment bag without the wheeled assembly.
FIG. 6 is a rear view of the pocket assembly.
DETAILED DESCRIPTION
Refer now to the Figures in which like referenced numerals correspond to like parts throughout the several views. FIG. 1 is a perspective view of the preferred embodiment of the present invention, with the rolling garment bag 10 opened. The rolling garment bag 10 comprises a garment bag 16 and a wheeled assembly 60 removably attachable to the garment bag 16.
The garment bag 16 has a front panel 18 and a rear panel 24, a top panel 30 and a bottom panel 36, and two side walls 40 and 46. The front panel 18 is sewn to the top panel 30, bottom panel 36, and side walls 40 and 46. The panels, 18, 24, 30, 36, and walls 40 and 46, are manufactured of 900 D Polyester with two-time PU coating manufactured by E.I. DuPont de Nemours Corp. Those skilled in the art will recognize that the panels may be formed of different materials, including various durable cloths, and that the front panel 18, top panel 30, bottom panel 36, and side walls 40 and 46 may be formed of one piece of material. A conventional zipper 51 and associated pocket are shown on panel 18. Those skilled in the art will recognize that other pockets may be placed on the panels and/or inside the garment bag.
The rear panel 24 is sewn to the right side wall 46 along edge 38. Zipper teeth 26 circumscribe the remaining three sides of the rear panel 24. Zipper teeth 26 correspond to zipper teeth 32 on top panel 30, side wall 40 and bottom panel 36. When the zipper teeth 26 and 32 are mated using sliding fastener 33, the garment bag 16 is closed. A hanger hook 59 extends upwardly from rear panel 24. Zipper teeth 26 and 32 are formed of #9 Decathlon Plastic Tooth (YKK), manufactured by in the preferred embodiment.
On the other hand, when zipper teeth 26 and 32 are disengaged, as seen in FIG. 1, the rear panel 24 may be swung about edge 38. Therefore, the user has access to the interior of the garment bag 16 using zipper teeth 26 and 32. Further, the garment bag may be hung by hangers 57 and 59 when in an open position.
FIG. 2 is a perspective view of the side wall 46 and top panel 30 of the preferred embodiment of the present invention. Zipper teeth 32 are sewn along the edge of the top panel 30.
A stiffener 52 is attached to top panel 30 and partially down side walls 40 and 46. The stiffener 52 is a U-shaped piece of PVC material. Rivets 54 connect the stiffener 52 to the garment bag 16 along top panel 30 and downward along side walls 40 and 46 approximately 14". A second U-shaped stiffener 53, corresponding in structure to stiffener 52, is rivoted to the bottom panel 36 of the garment bag 16. The second stiffener 53 extends upward into side walls 40 and 46 approximately 1441, and is rivoted to the side walls 40 and 46. The stiffeners 52 and 53 provide rigidity to the frame of the garment bag 16. Those skilled in the art will recognize that the stiffeners 52 and 53 may be affixed to the garment bag 16 in a variety of manners. The stiffeners 52 and 53 are made of polyvinyl chloride, although those skilled in the art will recognize that other materials may be utilized.
The stiffeners 52 and 53 extend 14" into side walls 40 and 46 so that the horizontal center of the garment bag 16 is pliable. Therefore, the garment bag 16 may be folded about a horizontal line running through handle 56 (FIG. 3). When the garment bag 16 is folded in half, the stiffeners 52 and 53 allow the bag 16 to stand-up.
Referring back to FIG. 1, a bag hanger hook 57 is rivoted to stiffener 52 on top panel 30. A zippered pocket 58 is positioned immediately adjacent the hook 57. The pocket 58 is large enough to hold hook 57. Therefore, when the hook 57 is not in use it can be stored in pocket 58.
FIG. 3 is a frontal view of the preferred embodiment of the rolling garment bag 10 folded and ready for transport. Handle 56 protrudes upward so the traveler may lift and carry the rolling garment bag 10.
The wheeled assembly 60 is affixed to the front of the rolling garment bag 10. The wheeled assembly 60 includes a top surface 82, a bottom surface 83, a front surface 84 and side surfaces 86a and b. The wheeled assembly 60 is made from the same material as front panel 18 in the preferred embodiment.
A rigid frame formed of stiffeners 68 (FIG. 4) circumscribes the interior of the wheeled assembly 60. The stiffener frame 68 provides a rigid frame for the wheeled assembly 60.
A retractable handle 62 extends from the top surface 82 of wheeled assembly 60. The handle 62 may be pulled upward and fixed into position so that the user can pull the rolling garment bag 10 using wheels 72a and b. Wheels 72a and b are known to those skilled in the art.
Wheels 72a and b protrude from the bottom surface 83 of the wheeled assembly 60. Wheels 72a and b protrude below the bottom panel 36 of the garment bag 10, so that the rolling garment bag 10 may be rolled on wheels 72a and b. The user can roll the rolling garment bag 10 by pulling on retractable handle 62 to urge the rolling garment bag in a direction aligned with the wheels 72a and b.
The preferred embodiment of the rolling garment bag 10 has a relatively narrow width. Therefore, the rolling garment bag 10 may be stored in the overhead bin of an airliner, obviating the need to check the rolling garment bag 10.
Folding flap 41 is made of the same material as wheeled assembly 60. Velcro connections 44, familiar to those skilled in the art, disengagingly affix flap 41 to the wheeled assembly 60. Lowering the zippers 42 and 43 allows easier access to the contents of wheeled assembly 60 when flap 41 is raised. As will be familiar to those skilled in the art, many pockets or attachments, such as zippered pocket 45, may be provided on wheeled assembly 60.
FIG. 4 is a rear view of the wheeled assembly 60. Stiffener frame 68 is attached to the wheeled assembly 60 by a plurality of rivets 64. The wheeled assembly 60 has an open face 88 that is closed by affixing the wheeled assembly to the garment bag 16.
Handle 62 on top surface 82 of the wheeled assembly 60 is shown partially extended. Handle 62 telescopes into tubes 70a and b. An interference fit between handle 62 and tubes 70a and b allows the handle to be extended and fixed in a variety of positions. Those skilled in the art are familiar with such interference fit mechanisms.
Tubes 70a and b extend from top surface 82 of the wheeled assembly 60 to the wheel casings 74a and b. The rigid handle 62 and tubes 70a and b provides support under the garment bag 16 when the user tilts the garment bag 16 forward and rolls the assembly forward.
Wheels 72a and b are rotatably bolted to wheel casings 74a and b. Wheel casings 74a and b are rigid covers affixed to the axles of wheels 72a and b and precluding the contents of the wheeled assembly 60 from contacting wheels 72a and b.
Support plate 80 is riveted to the bottom surface of the wheeled assembly 60. The support plate 80 is inserted into an opening 90 (FIG. 5) in the bottom of the garment bag 16 to provide support under the garment bag 16 during transport. The support plate 80 further provides leverage when the garment bag 16 is pivoted onto the wheeled assembly 60 for transport. The support plate is of polyvinyl-chloride (PVC) in the preferred embodiment.
FIG. 5 is a frontal view of the garment bag 16 with the wheeled assembly 60 unattached. Zipper teeth 100 circumscribe the lower region of the front panel 18 of the garment bag 16. Zipper teeth 102 circumscribing the open face 88 of the wheeled assembly 60 correspond to zipper teeth 100 on the garment bag 16 (FIG. 4). Slidable connector 104 on the wheeled assembly 60 permits zippers 100 and 102 to be connected and disconnected. Further, zipper teeth 100 are sewn onto a protruding lip of material 101 that facilitates connecting zipper teeth 100 and 102. The wheeled assembly 60 may be detachably affixed to the garment bag 16 by mating sliding connector 104 with zipper 100, as is familiar to those skilled in the art. Attaching wheeled assembly 60 to the garment bag closes open face 88.
A zippered opening 90 is located on the bottom of the garment bag 16. Zipper 92 is retracted, creating an opening, when the wheeled assembly 60 is to be mounted on the garment bag 16. The support plate 80 on the bottom of the wheeled assembly 60 extends into the zippered opening 90 when the wheeled assembly is mounted on the garment bag 16.
FIG. 6 is a rear view of a pocket assembly 110 that may be attached to the garment bag 16 in the present invention. If the wheeled assembly 60 is not mounted on the garment bag 16, zipper teeth 100 on the garment bag 16 (FIG. 5) are not occupied. Zipper teeth 112 circumscribing the interior open face of the pocket assembly 110 correspond to the zipper teeth 100, allowing the pocket assembly 110 to be mounted and affixed on the garment bag 16. Fastener 114 is utilized to connect zipper teeth 100 and 112, as is familiar to those skilled in the art.
Pocket assembly 110 is constructed of the same material as the garment bag 16. The pocket assembly 110 has a top surface 120, bottom surface 122, front surface 124 and side surfaces 126a and b. Pocket assembly 110 is constructed similarly to the wheeled assembly 60, except no wheel and handles are on the pocket assembly 110.
A zippered opening 116 allows the traveler to access the interior of the pocket assembly 110 when the pocket assembly 110 is affixed to the garment bag 16. Zippered opening 90 (FIG. 5) may be closed when the pocket assembly 110 is affixed to the garment bag 16.
During transport, the wheeled assembly 60 is affixed to the front of the garment bag 16. The garment bag 16 stands on its edges and on the wheels under the wheeled assembly when folded. Stiffeners 52 and 53 in the garment bag 16, and the stiffener frame 68 in the wheeled assembly 60, provide a frame-like structure that greatly limits wrinkling of the garments in the rolling garment bag 10 during transport. Thus, the basic structure of a garment bag for carrying formal clothes is retained. Additionally, portability is enhanced through provision of a wheeled assembly.
While this invention is described in detail with particular reference to the preferred embodiment thereof, it will be understood that other variations and modifications can be made without departing from the spirit and scope of the invention as defined in the appended claims.
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A wheeled assembly that is removably attachable to a garment bag. The wheeled assembly is affixed to the folded garment bag with a zipper. The wheeled assembly is tilted forward and the attached garment bag rides on the wheeled assembly. Both the wheeled assembly and the garment bag have rigid structural features to provide the structural integrity needed to roll the garment bag. The wheeled assembly has a retractable handle that telescopes upward so that a user can pull the rolling garment bag.
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This application claims the benefit of the Korean Application No. P2004-13270; P2004-13271 and P2004-13266 filed on Feb. 27, 2004, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a drum type washer with dry function, and more particularly, to an apparatus for supplying hot air in a drum type washer with dry function, by which a laundry within a drum can be dried in a manner of forcibly blowing the generated hot air to the drum.
2. Discussion of the Related Art
Generally, a drum type washer with dry function is an apparatus for removing dirt or filth from a laundry inputted to a drum using a proper detergent and mechanical force through washing, rinsing, dewatering, and drying cycles.
FIG. 1 is a cross-sectional diagram of a drum type washer with dry function according to a related art, and FIG. 2 is a perspective diagram of a hot air supplying device consisting of a drying duct and a blower according to a related art.
Referring to FIG. 1 and FIG. 2 , a tub 4 is installed within a cabinet 2 to be horizontally supported by a spring and damper (not shown in the drawing). A cylindrical drum 5 is rotatably installed within the tub 4 to wash a laundry inputted thereto. A motor 7 is installed under the tub 7 . A drive pulley (not shown in the drawing) connected to the motor 7 via a belt 6 is provided in rear of the tub 4 to rotate the drum forward or reversely. A water supply hose 9 connected to a water supply source is provided to one side of an upper part of the cabinet 2 to supply a detergent to the tub 4 via a detergent box 8 . A drain hose 11 connected to a drain pump 10 is provided to one side of a lower part of the cabinet 2 to drain water within the tub 4 outside. And, a door (not shown in the drawing) opening/closing a front portion of the drum 5 is revolvably provided to a front portion of the cabinet 2 .
A drying duct 30 , in which a heater 36 and a blower 34 are built to blow out hot air into the tub, is provide over the tub 4 . A condensing duct 40 is provided to one side of the tub 4 . One end of the condensing duct 40 communicates with a lower lateral part of the tub 4 and the other end of the condensing duct 40 communicates with the drying duct 30 . Hence, the condensing duct 40 forms a circulation path together with the drying duct 30 and the tub 4 . A water supply nozzle 4 is provided to one side of the condensing duct 40 to remove humidity from air introduced from the tub 4 in a manner of flowing cooling water.
The drying duct 30 , as shown in FIG. 2 , consists of a metallic upper housing 31 , a metallic lower housing 32 , and a blower cover 33 connected to one side of the upper housing 31 . Moreover, a motor 35 and the blower 34 are assembled to each other centering on the same axis by leaving the blower cover 33 in-between.
The heater 36 is attached within the drying duct 30 to heat air flowing within the duct.
A motor guide 37 is provided to the blower cover 33 to have a recess for receiving the motor 35 therein. A power cable guide slot is provided to the motor guide 37 to guide a power cable 39 of the motor 35 . A flange 33 a is provided to an outer circumference of the blower cover 33 to be loaded on an outer circumference of the lower housing 32 , and a plurality of locking holes 33 b are provided to both sides of the flange 33 a for screw-coupling with the lower housing 32 .
The above-configured drying duct and blower 30 and 34 according to the related art are manufactured by iron-casting.
However, the related art drum type washer with dry function has the following problems or disadvantages.
First of all, a locking place of the lower housing configuring the drying duct is varied according to a washing capacity of the washer, and a size of the blower drive motor and an installation direction of the power cable 39 are changed as well. Hence, the blower cover 33 needs to be modified to correspond to the washing capacity of the washer. If the blower cover is applied to a specific washing capacity only, the product cost is raised as well as maintenance and management get difficult.
Secondly, the upper and lower housings 31 and 32 configuring the drying duct 30 of the related art drum type washer with dry function are manufactured by iron casting using steel. And, the blower 34 and the blower cover 33 are made of steel or stainless steel by casting or metallic processing. Hence, the corresponding product costs are high to raise the product cost of the washer/dryer.
Specifically, in case of the blower 34 , a rim 34 a , a base 34 b , and a blade 34 c need to be separately formed to be assembled. Hence, the corresponding manufacturing process is considerably complicated to further raise the product cost.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a drum type washer with dry function that substantially obviates one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a drum type washer with dry function, by which a manufacturing process of a drying duct is simplified and by which a product cost is lowered.
Another object of the present invention is to provide a drum type washer with dry function, by which compatibility of a blower cover is enhanced to cope with variable sizes of a drying duct and motor according to washing capacity.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, an apparatus for supplying hot air in a drum type washer according to the present invention includes a first duct housing provided to a tub included in the drum type washer with dry function, a second duct housing provided to an upper side of the first duct housing, a blower cover provided to the upper side of the first duct housing adjacent to the second duct housing, the blower cover being formed of a synthetic resin based injection material, a heater provided between the first and second duct housings, a motor provided to the blower cover, and a blower provided under the blower cover, the blower being rotatably connected to the motor.
In another aspect of the present invention, an apparatus for supplying hot air in a drum type washer with dry function includes a first duct housing provided to a tub included in the drum type washer, a second duct housing provided to an upper side of the first duct housing, a blower cover provided to the upper side of the first duct housing adjacent to the second duct housing, the blower cover being formed of a synthetic resin based material, the blower cover having a recess, a heater provided between the first and second duct housings, a motor coupled with the recess of the blower cover, a blower under the blower cover, the blower being rotatably connected to the motor, and a motor guide protruding upward along an outer circumference of the recess of the blower cover, the motor guide including a plurality of bosses having screws locked therein for coupling with the motor, respectively and at least one escape recess for receiving a projected portion of a locking screw separately locked in the motor.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:
FIG. 1 is a cross-sectional diagram of a drum type washer with dry function according to a related art;
FIG. 2 is a perspective diagram of a hot air supplying device consisting of a drying duct and a blower according to a related art;
FIG. 3 is a projected perspective diagram of a hot air supplying apparatus according to one embodiment of the present invention;
FIG. 4 is a graph of temperature measurement results at major parts of a blower and drying duct on a drying operation;
FIG. 5 is a projected perspective diagram of a hot air supplying apparatus according to another embodiment of the present invention;
FIG. 6 is a projected perspective diagram of major parts of the hot air supplying apparatus of FIG. 5 ; and
FIG. 7 is a perspective diagram of a lock hole comprising a square shape.
FIG. 8 is a perspective diagram of a lock hole comprising a square shape.
FIG. 9 is a perspective diagram of different exemplary representations of a lock hole comprising an oval shape.
FIG. 10 is a perspective diagram of different exemplary representations of a lock hole comprising a rectangular shape.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
FIG. 3 is a projected perspective diagram of a hot air supplying apparatus according to one embodiment of the present invention.
Referring to FIG. 3 , a hot air supplying apparatus 300 according to one embodiment of the present invention includes a lower housing 320 forming a air-flowing passage, an upper housing 310 assembled to a top portion of the lower housing 320 , and a blower cover 330 assembled to a top portion of the lower housing 320 at one side of the upper housing 310 to contact with the upper housing 310 . Additionally, the upper housing 320 , the lower housing 310 , and the blower cover 330 construct a drying duct for air-flowing.
The blower 340 is provided to one end of the lower housing 320 , and more specifically, to a portion of the lower housing 320 communicating with the condensing duct 40 in FIG. 1 , and a heater 360 is provided to an opposite side to the lower housing 320 to heat air blown by the blower 340 .
The lower housing 320 can be formed by casting using steel. Moreover, the upper housing 310 can be formed by pressing using a zinc plate or preferably by injection molding using a synthetic resin material such as a plastic material. Alternatively, the upper housing 310 can be formed by casting using steel like the lower housing 320 as well.
Preferably, the blower 340 is formed by injection molding of a synthetic resin material having a high heat-resistant property.
Preferably, the blower cover 330 is formed by injection molding of a synthetic resin material having a high heat-resistant property.
A recess 331 for receiving a motor 350 driving the blower 340 therein is provided to the blower cover 330 . Moreover, a motor guide 370 protrudes from a circumference of the recess 331 to load the motor 350 therein and to fix the motor 350 thereto. A rotational shaft of the motor 350 penetrates into the blower cover 330 to be coupled to the blower 340 for shaft-coupling.
An operation of the hot air supplying apparatus according to the present invention is explained as follows.
FIG. 4 is a graph of temperature measurement results at major parts of a blower and drying duct on a drying operation.
Referring to FIG. 4 , temperature sensors are attached to a portion A of the blower cover 300 having the blower 340 installed therein, a heater entrance B in the vicinity of a connecting part between the blower cover 330 and the upper housing 310 , and a portion C of the upper housing 310 provided over the heater 360 , respectively. A drying cycle is then carried out to measure temperature variations of the respective portions A, B, and C according to time.
As a result of the test, the vicinity A of the blower 340 has a maximum temperature of 75° C. and the entrance B of the heater 360 has a temperature of about 80° C.
Namely, the vicinity of the blower cover 330 in the vicinity of the blower 340 has a prescribed amount of heat dissipation and cooling effects attributed to a rotation of the blower 340 . Air that passes through the blower 340 and the blower cover 330 is further passed through the condensing duct 40 in FIG. 1 to decrease in humidity and temperature. Hence, the temperature is not so high as to break down the synthetic resin material having high heat-resistant property.
Based on the measurement result, a synthetic resin having an excellent heat-resistant property such as PVDF (polyvinylidene fluoride), POM (polyactal copoymer), and the like is preferably used as a material having excellent resistant properties against moisture, strong alkalinity, and oxidation. The POM can sustain excellent properties including mechanical strength, hardness, creep-proof, and the like as well as various kinds of mechanical feasibility by 100° C. Furthermore, the PVDF has a melting point of 170˜185° C. and a continuously usable temperature of 120° C. that is the lowest among fluoride resins. Yet, the PVDF has excellent processing features of injection molding, pressing forming, and the like as well as excellent mechanical and weathering properties.
Of course, other synthetic resins such as PC (polycarbonate), each of which has high heat-resistant property and good low-temperature characteristic and us usable between (−)100˜135° C., can be employed as well.
If the blower 340 , the blower cover 330 , and the upper housing 310 are formed by an injection process using a highly heat-resistant synthetic resin, they can be manufactured by a single process unlike the casting method which requires multiple steps. Hence, it is able to lower product cost, thus reducing overall product cost.
A hot air supplying apparatus according to another embodiment of the present invention is explained with reference to FIGS. 5 to 7 as follows.
First of all configurations and materials of a lower housing 1320 , an upper housing 1310 , and a blower 1340 of a hot air supplying apparatus 1300 according to another embodiment of the present invention are substantially identical to those of the former hot air supplying apparatus 300 according to one embodiment of the present invention. However, the hot air supplying apparatus 1300 according to another embodiment of the present invention differs from the apparatus 300 in configurations of a blower cover 1330 and a motor 1350 assembled to the blower cover 1330 .
Specifically, a recess 1331 is provided to the blower cover 1330 to receive the motor 1350 therein. A motor guide 1370 protrudes upward along a circumference of the recess 1331 . A plurality of bosses 1371 are built in one body of the motor guide 1370 to fix the motor 1350 and the motor guide 1370 to each other. A plurality of cable guide slots 1373 are provided to the motor guide 1370 to draw out a power cable 1352 of the motor 1350 that is loaded in the blower cover 1330 . Preferably, each top end of the cable guide slots 1373 is fully open.
A motor cover 1355 is fixed to a top portion of the motor 1350 via a plurality of locking screws 1356 . In doing so, each of the locking screws 1356 is slightly projected downward. Hence, it is preferable that a plurality of escape recesses 1372 are concavely provided to the motor guide 1370 to receive the corresponding locking screws 1356 therein, respectively. Each of the escape recesses 1372 plays a role in preventing a lower end of the projected locking screw 1356 from colliding with the motor guide 1370 , thereby smoothing the corresponding locking.
Meanwhile, the drum type washer with dry function is differently manufactured according to washing capacity such as 7.5 kg, 10 kg, and the like. Hence, a size and configuration of the motor 1350 driving the blower 1340 are designed differently to correspond to the washing capacity. The recess 1331 having the motor 1350 received therein has a depth enough for each of the various motors 1350 to be locked therein.
A position of the power cable 1352 for supplying power of the motor is varied according to the corresponding one of the various motors. Hence, a plurality of the cable guide slots 1373 are provided along a circumference of the motor guide 1370 not to interfere with the position of the power cable 1352 of the motor.
Meanwhile, a pump (not shown in the drawing) is provided to a lower part of the drum type washer with dry function. Moreover, a hose connected to the pump may traverse over the drying duct due to a configurational reason. Thus, if a hose or cable of an external device traverses over the drying duct, a guide part 1338 and a support recess 1339 are preferably provided to one side of the motor guide 1370 to support the hose or cable. In this case, the support recess 1339 having an open top is provided to the guide part 1338 .
A flange 1335 is provided to a circumference of the blower cover 1330 except the portion connected to the upper housing 1310 to be loaded on an outer circumference of the lower housing 1320 . A plurality of locking holes 1336 are provided to the flange 1335 . A plurality of the locking holes 1336 are preferably provided to leave a prescribed distance from each other to secure compatibility of the lower housing 1320 of which locking position through the locking holes 1336 varies according to capacity of the washer/dryer. Optionally, each of the locking holes 1336 may be a long hole 1337 .
Also, a shape of the locking hole comprises at least one of a circular, square, oval, or rectangular shape. Exemplary and non-limiting perspective views and representations of locking holes comprising a square, oval and a rectangular shape are respectively illustrated in FIGS. 8–10 .
Preferably, the blower 1340 and the blower cover 1330 are formed by injection molding using a synthetic resin material having an excellent heat-resistant property such as plastic. Preferably, the motor guide 1370 is formed by injection molding together with the blower cover 1330 . Alternatively, the motor guide 1370 can be separately formed by injection molding and assembled to the blower cover 1330 .
An assembling process of the above-configured hot air supplying apparatus according to the present invention is explained as follows.
First of all, the motor cover 1355 is assembled to the top portion of the motor 1350 using the locking screws 1356 . In doing so, the locking screws 1356 are slightly projected downward.
Subsequently, the motor 1350 is inserted inside the recess 1331 of the blower cover 1331 to be loaded in the motor guide 1370 . In doing so, the power cable 1352 of the motor 1350 is drawn out via the guide slot 1373 . Furthermore, the locking screws 1356 are inserted in the escape recesses 1372 of the motor guide 1370 to prevent interference with a surface of the motor guide 1370 , respectively.
Screws 1358 are then locked via the locking holes 1357 of the motor 1350 and the bosses 1371 of the motor guide 1370 , respectively to fixedly assemble the motor 1350 to the motor guide 1370 .
Once the motor 1350 is fixed to the blower cover 1330 , the blower cover 1330 , as shown in FIG. 5 , is loaded on the lower housing 1320 . Subsequently, screws 1380 are locked via the locking holes 1336 and long holes 1337 of the flange 1335 and the locking holes 1322 of the lower housing 1320 , respectively to assemble the blower cover 1330 to the lower housing 1320 .
As mentioned in the above explanation, if positions of the locking holes 1322 of the lower housing are changed according to the capacity of the washer, the screws 1358 can be locked in another adjacent locking holes 1336 among the locking holes 1336 , respectively. Moreover, since the long holes 1336 are provided for another screw locking, it is able to cope with a slight position variation of the corresponding locking hole 1322 of the lower housing 1320 . Hence, without changing the structure and size of the blower cover and the locking hole position, and the like despite the variation of the applicable model according to the washing capacity, it is able to configure the hot air supplying apparatus using the same blower cover.
Moreover, even if the size of the motor 1350 is changed, the locking screw 1356 projected from the motor 1350 avoids contacting with the motor guide 1370 and the power cable 1352 of the motor 1350 can be easily drawn out via one of the cable guide slots 1373 provided to various locations of the motor guide 1370 . Hence, it is able to fix the motor 1350 variously differing in size thereto using the same blower cover 1330 without modifying the structure of the blower cover 1330 .
Accordingly, by forming the upper housing with the zinc plate and by forming the blower and blower cover with the synthetic resin material by injection molding, the present invention simplifies the manufacturing process and lowers the product cost, thereby enhancing user's economical advantage and reliability on the product and manufacturer.
Moreover, the same blower cover is applicable despite modifications of the structures and sizes of the lower housing and motor according to the capacity of the washer, whereby the present invention enhances compatibility, lowers the product cost, and facilitates maintenance and management thereof.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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The present invention provides a drum type washer with dry function, by which a product cost is lowered and by which compatibility of a blower cover is enhanced. The present invention includes a first duct housing provided to a tub included in the drum type washer, a second duct housing provided to an upper side of the first duct housing, a blower cover provided to the upper side of the first duct housing adjacent to the second duct housing, the blower cover being formed of a synthetic resin based injection material, a heater provided between the first and second duct housings, a motor provided to the blower cover, and a blower provided under the blower being rotatably connected to the motor.
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BACKGROUND OF THE INVENTION
The present invention relates to an improved engine fuel control systems, and more specifically to an engine fuel control system which compensates for changes in engine aspirated air due to changes in altitude, atmospheric temperature and/or barometric pressure as disclosed and claimed in our co-pending application Ser. No. 06/685,908 with the Title GAS-COUPLED TRANSDUCER DEVICE which is now abandoned; and as disclosed and claimed in our co-pending application Ser. NO. 06/788,634 with the title FUEL CONTROL SYSTEM FOR INTERNAL COMBUSTION ENGINES.
Several types of air flow rate sensing devices as part of engine fuel control systems are known to exist. One of which (a thermal flowmeter) is described in the U.S. Pat. No. 4,275,695. While being widely used, such thermal flowmeters are characterized by a multitude of shortcomings. Such as for instance, the pulsating, electric current flow within a heated wire located in the engine air induction tube, caused by pulsating heat exchange as a consequence of pulsating air flow in step with the opening and closing of the engine intake valves. Still other limitations may be found in the possible braking, and the formation of unwanted deposits on the heated wire. This, and other shortcomings may have adverse effects on the smooth operation of the engine fuel injection systems. To eliminate such shortcomings, requires extensive, and costly signal conditioning components. Other systems are described in the U.S. Pat. No. 4,311,042, and 4,457,167; whose principle of operation, except for the addition of electronic signal smoothing and linearizing components are basically as in the heretofore discussed system, and are therefore subject to basically the same limitations. While a still further U.S. patent with the U.S. Pat. No. 4,457,166 describes a device based on the subtraction of an appropriated number of Karman vortex pulses from a number of measured Karman vortex pulses.
SUMMARY OF THE INVENTION
To ascertain the mass flow rate of any gas in motion, it is necessary to know the cross sectional area at a certain measuring zone within a flow system under consideration; as it is necessary to know the velocity of the gas within said zone, and the density of the particular gas. Wherein, the cross sectional area times the velocity times times the density of the gas is equal to the mass flow rate, thereof. The preferred embodiments of the mass flow rate measuring device of the present invention serves a twofold purpose; first, to provide the engine fuel injector(s) with an electric signal to produce at any engine throttle position, engine speed and load as well as atmospheric condition the correct air/fuel mixture necessary for complete combustion within the cylinders of the engine; and second, to produce at any of the aforesaid conditions, the correct air/fuel mixture necessary to achieve the highest degree of fuel efficiency.
Since it is however difficult to measure the velocity of air within an engine air induction system, a section of the air induction tube is provided with an internally disposed, streamlined constriction having a throat of well defined cross sectional area; which makes it indirectly possible, to measure the velocity of air by measuring the decrease in pressure generated by the proportional increase in velocity as the air passes through the narrow venturi throat. Hence, since the cross sectional area at the point of measurement is a known constant, the rate of produced difference in pressure between the point of measurement and atmosphere may be utilized to indicate the volumetric rate of air flow.
The systems of the prior art require complex, multi-transducer measurements to produce an indirect, computer correlated electric output, proportional to the mass flow rate of air in motion, thereby increasing cost. Whereas, the embodiments of the present invention produce a single, electric output, which by virtue of simplicity, greatly reduces cost.
The mass flow sensing system of the present invention basically comprises two individual fluid communicative connected assemblies. One of which, is an air flow responsive component which does not require an electric input, nor does it provide an electric output. Whereas, the other assembly consists of an acoustically responsive component, which requires an electric input, to provide a modified electric output.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to provide low cost means for measuring the mass flow rate of engine aspirated air without the limitations, characteristic of the prior art.
Another object of the present invention is to provide a single, low cost transducer means for measuring the mass flow rate of air in motion.
A further object of the present invention is to provide an improved, low cost, and efficient engine fuel control system comprising mass flow sensing means for engine aspirated air.
A still further object of the present invention is to provide low cost means for making a single measurement on the mass flow rate of engine aspirated air while compensating for changes in concurrent atmospheric conditions.
Yet still another object of the present invention is to provide means for producing an electric signal proportional to the mass flow rate of engine aspirated air, which is utilized in controlling the fuel-injector(s) to obtain at any throttle position, engine load and environmental conditions a correct air/fuel mixture.
The features which are believed to be characteristic of the present invention, both as to their organization and method of operation, together with further objects and advantages will be better understood from the accompanying drawing which we have chosen for purpose of explaining the basic concept of the invention. It is to be clearly understood however, that the invention is capable of being implemented into other forms and embodiments within the scope and spirit of the defining claims by those skilled in the art, such as for instance applications involving the mass flow measurement of any gas, which other forms and embodiments will be taken advantage of.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 represents the sectioned view of the preferred embodiment of the present invention comprising a venturi tube, and thereto fluid communicative connected, ultrasonic transducer.
FIG. 2 represents the electric diagram for the device in FIG. 1.
FIG. 3 represents the sectioned view of an alternate embodiment of the device in FIG. 1, comprising two ultrasonic transducers, one for measuring the volumetric rate of air flow, and the other, for measuring the density of atmospheric air.
FIG. 4 represents the electric diagram for the device in FIG. 3.
FIG. 5 represents an alternate embodiment comprising an ultrasonic ceramic emitter sub-assembly, and a separate, ultrasonic ceramic receiver sub-assembly.
FIG. 6 represents a venturi tube having a integrally disposed ultrasonic transducer assembly, including electronic circuit block diagram.
FIG. 7 is a graphic illustration of the shift in phase of the device in FIG. 1.
FIG. 8 is a graphic illustration of the shift in phase of the first device in FIG. 3.
FIG. 9 is a graphic illustration of the shift in phase of the second device in FIG. 3.
FIG. 10 is a graphic illustration of the shift in phase in FIG. 5.
DESCRIPTION
In accordance with the preferred embodiment of the present invention, FIG. 1 represents the venturi tube 1 being connected via suitable fluid transport means 2, to the ultrasonic transducer assembly 3. The venturi tube consists of a length of tube 4 of cross sectional area (a), having the air inlet 5, and outlet 6; and comprises the internally disposed constriction 7 having a throat 8 of substantially reduced cross sectional area (b). The fluid communicative passageway 9 extends perpendicular to the main-stream of air flow from throat 8 to port 10 outward, so as to form via the fluid transport means 2, a fluid communicative relationship with the ultrasonic transducer assembly 3. The ultrasonic transducer assembly 3 comprises the first and second housing portions 11 and 12. The first as well as the second housing portions are provided with radially outward extending flanges 13 and 14. Flange 13 is provided with a series of longitudinally extending pegs 15 of the well defined length (c); whereas flange 14 is provided with the radially extending planar surface 16 having the internally treated apertures 17 being located so as to match the geometry of the longitudinally through pegs 15 extending apertures 18. A set of screws 19 extend trough apertures 18 of pegs 15 so as to combine, and securely fix the first and second housing portions by being in a threaded engagement with the internally threaded apertures 17 of flange 14. In the arrangement, pegs 15 serve the purpose of providing a series of large, circumferentially spaced openings between atmosphere and the device's interior. Housing portion 11 comprises the sub-assembly 20, having the axially flexible bellows 21, which is hermetically closed at end 22 by the disk like member 23 having the perpendicular to the center 24 oriented, planar wave reflecting surface 25. Sub-assembly 20 further comprises the disk like support member 26 which is hermetically fixed to bellows end 27. The disk like support member 26 comprises the threaded stem 28 having the longitudinal air passageway 29. Stem 28 extends in a threaded engagement with the internally threaded aperture 30 through housing boss 31, so that surface 25 of member 23 is axially adjustable, and fixed in the adjusted position, by tightening the nut 32 against the boss 31. Housing portion 12 comprises concentrically within disposed the annular, resilient member 33 being fixed by suitable means with its cylindrical outer wall 34 to the housing cylindrical inner wall 35. Housing portion 12 further comprises the piezoelectric, ultrasonic generator sub-assembly 36 (such as e.g., the Ultrasonic Ceramic Transducer being commercially available at Projects Unlimited, Inc.). Sub-assembly 36 comprises the electric leads 37 and 38, as well as comprises the piezoelectric ceramic element incorporating the single emitter-receiver element 39, which serves the dual functions of emitting, as well as of receiving acoustic energy in form of sonic pressure pulses. Sub-assembly 36 is concentrically disposed within resilient member 33, by being fixed via suitable means with its cylindrical outer wall 40 to the cylindrical inner wall 41 of member 33.
In operation, a constant stream of air enters inlet 5 of venturi tube 4 to pass the point of measurement at the narrowest portion of flow constricting throat 8. As the air enters the constriction, part of its pressure is converted to an proportional increase in velocity, accompanied by a proportional decrease in pressure at fluid passageway 9. The reduced pressure within venturi throat 8, causes a proportional axial contraction of bellows 21 as a consequence of higher atmospheric pressure being exerted on the outer surface 25 of member 23; which in turn, tends to increase the distance between wave reflector surface 25, and the wave emitting and receiving element 39 located at end 37 of the transducer sub-assembly 36. This function reverses, as the volumetric rate of flow within the venturi tube decreases, and thereby allowing the member 23 and bellows 21 to return to their equilibrium position.
FIG. 2, shows the oscillator 43 connected in series with resistor 44, capacitor 45, and the piezoelectric ceramic element 46 to ground 47. Wherein the electric lead 48 and lead 49 represent the leads 37 and 38 in FIG. 1. In the circuit, the crystal controlled oscillator produces an alternating electric output of stable frequency and amplitude, which is applied across the piezoelectric ceramic element 46 whose resonance frequency is equal to the oscillator frequency. Thereby, causing element 46 to vibrate mechanically in phase with the frequency of the applied electric current. The mechanical vibrations of piezoelectric ceramic element 46 and the thereto coupled emitter-receiver element 39 produces acoustic energy in form of pressure pulses which are propagated to the wave reflecting surface 25 of member 23, from where the they are reflected to return, and to impinge on the emitter-receiver element 39. The oscillator 43 is series connected with resistor 44 and capacitor 45 to form a constant current source of greater resistance than the impedance of the piezoelectric ceramic element 46; the output voltage at leads 48a, and 49a is therefore proportional to the impedance. Since the piezoelectric element will only produce mechanical vibrations when electrically stimulated at its resonant frequency, the change in the electrical impedance in a function of antiresonant frequencies generated by a shift in phase between the mechanical vibrations of the piezoelectric element and the thereon impinging reflected sonic waves. Whereby the shift in phase, may be the consequence of changes in air temperature, or changes in the distance between the emitter-receiver element 39, and the wave reflecting surface 25 of member 23; which in turn, is caused by the contraction or expansion of bellows 21.
Referring to the diagram in FIG. 7. As shown, if the wave reflecting surface is located at the node, position (A) of the propagated wave (a1), the propagated, and the reflected wave (a2) will be in phase. The returning wave will therefore be in resonance with the emitting surface (G) of the piezoelectric element. At this condition, the piezoelectric element has a low impedance, and therefore causes the transducer output voltage to be high. At a no flow, and standard temperature condition through the venturi tube, the wave reflecting surface (R) is moved, to be fixed at position (D). Thereby causing the reflected wave (a3) to undergo the shift in phase as represented by (H). This in turn produces an antiresonance of high magnitude, thereby causing the piezoelectric element to change to a higher impedance, and inversely, causing the transducer output voltage to be low. Any movement of the wave reflecting surface (R) from position (D) toward position (E) or (A) caused by increasing air flow through the venturi tube, causes the reflected wave to undergo the shift in phase (C). Thereby lowering the antiresonance, as as well as the impedance of the piezoelectric element, accompanied by an inverse increase in transducer output voltage. In addition, either a leading, or a lagging shift in phase may occur as a consequence of changes in the velocity of sound, due to changes in the temperature of air between the emitting and reflecting surface. The diagram e. g., shows an increase in the temperature between the emitting and the reflecting surface, thereby causing the propagated wave (a1), to shift to (a5), and the returning wave to shift from (a4) to (a6). The total of which being represented by (F). This causes an additional antiresonance, accompanied by a proportional increase in impedance of the piezoelectric element, and hence causes an inverse lowering of the transducer output voltage. Wherein, the shift in phase (C) measures the volumetric rate of air flow through the venturi, minus the shift in phase (F) caused by the influence of changes in temperature of intervening air between the emitting and reflecting surface, hence: (C) minus (F) is equal to the transducer output as represented by the single output signal (V).
FIG. 3 represent an alternate embodiment of the present invention comprising the engine throttle-body device 55 being connected in a fluid communicative relationship via suitable fluid transport means 56 to the first ultrasonic transducer assembly 57, and via suitable fluid transport means 58 to the second ultrasonic transducer assembly 59. The throttle-body assembly 55, basically consists of a length of a suitable tube 60 being provided with the air inlet 61 and outlet and 62; and comprises the internally disposed, streamlined, venturi constriction having the narrow throat portion 63 of substantially reduced cross sectional area. The venturi constriction is provided with the fluid passage 64 extending laterally, relative to the mainstream of air flow from throat 63 to port 65 outward, so as to connect with fluid transport means 56. Throttle-body 55 further comprises the tubular member 66 extending downstream from the throttle valve 67 inward; and comprises further downstream the fuel injector 68. Except for the fluid communicative ports, the second transducer assembly is an exact duplication of the first transducer assembly. For purpose of simplicity therefore, only the component parts of the first assembly are provided with reference numbers which are also applicable to like parts of the second transducer assembly 59. The second housing structure comprises the port 69 which is fluid communicative connected to fluid transport means 58; as well as comprises port 70 which remains open to provide a fluid communicative passage between chamber 71 and atmosphere. Whereas, the first housing structure comprises a port which is hermetically closed by plug 72; as well as comprises the port 73 which is fluid communicative connected to fluid transport means 56. The cylindrical housing structure 74 is inherently closed at one end, while being closed at the opposite end via the end cap 75 so as to form a chamber defined by the cylindrical inner wall 76, and end walls 77 and 78. The annular member 79 made of a suitable resilient material is fixed by suitable means to the housing cylindrical inner wall 76 so as to coaxial retain by suitable means, the ultrasonic transducer sub-assembly 80. Sub-assembly 80 comprises the electric leads 81 and 82, as well as comprises the emitter-receiver element 83 at end 84. The disk like member 85 having the sound reflecting surface 86 is concentrically provided with an externally threaded stem 87, which is engaged with the internally threaded boss 88, so that the distance (G) between the emitter-receiver element 83 and surface 86 of the disk member 85 may be axially adjusted. To prevent air stagnation within chamber 71, and to assure the measurement of air at concurrent atmospheric conditions, the tubular member 66 by virtue of slightly lower than atmospheric pressure at aperture 91 continuously removes a small amount of air from within chamber 71, while maintaining atmospheric pressure within the chamber 71.
The diagram in FIG. 8 pertains to the first transducer of the alternate embodiment as shown in FIG. 3. As shown, if in the no flow condition through the venturi tube the wave reflecting surface is positioned at the second node, the propagated wave (A) possesses the fixed amplitude (b1), and the fixed frequency as represented by length (G) plus (F) given by the oscillator output frequency. Thus, when the wave reflecting surface is located at the second node, the propagated wave (a1) and the reflected wave (a2) will be in phase, thereby producing a resonance between the reflected wave and the emitting surface of the piezoelectric element. This in turn, causes the piezoelectric element to assume a low impedance, and hence, to produce a high transducer output voltage. Due to the fixed frequency of the propagated wave, the movement of the wave reflecting surface from the second node to distance (G) from the emitting surface, causes the fixed shift in phase indicated by (D1), and (D2), thereby causing an antiresonance of high magnitude, which in turn, causes the piezoelectric element to assume a high impedance, and hence, to produce a low transducer output voltage. An additional shift in phase may be caused due to lowering the air pressure between the wave emitting and the wave reflecting surface. That is to say, the transmissibility of sound through air may vary as the pressure, from high, at maximum pressure, to zero at a total vacuum. Any pressure change within the transducer causes therefore, an additional shift in phase. As may be seen in the diagram, a lowering in pressure causes the reduction in the amplitude (b1) of the propagated wave, to the lower amplitude (B2) represented by the dotted line. In operation, the venturi suction pressure causes a proportional change in air pressure between the wave emitting and the wave reflecting surface. The amplitude of the propagated wave (b2) and the reflected wave (b3) will therefore follow any change in venturi suction pressure. This in turn, causes the shift in phase (C1) and (C2) thereby lowering the impedance of the piezoelectric element, and hence, causing an inversely high transducer output voltage (V) of the first transducer, which indicates the volumetric flow rate through the venturi tube. The second transducer 59, whose purpose is to senses the density of atmospheric air between wave reflecting surface 86 and emitter-receiver element 83 is adjusted to distance (H) to match distance (G) of the first transducer 57.
The diagram in FIG. 9 pertains to the second transducer of the alternate embodiment as shown in FIG. 3. As shown, if in the no flow condition, the wave reflecting surface (R) is positioned at the second node, the propagated wave (a) possesses the fixed amplitude (b1), and the fixed frequency represented by length (H) plug (F) which is given by the oscillator frequency. Thus, when the reflecting surface is located at the second node, the propagated wave (a1) and the reflected wave (a2) will be in phase, which produces the resonance between the reflecting wave and the emitting surface (E) of the piezoelectric element. The resonance causes the piezoelectric element to have an inverse low impedance, and therefore to produce a high transducer output voltage. Due to the fixed frequency of the propagated wave, the movement of the reflector surface (R) from the second node to distance (H) from the emitter surface (E), causes the fixed shift in phase indicated by (D1), and (D2). Thereby giving rise to an antiresonance of high magnitude, which causes the piezoelectric element to assume a high impedance, and inversely, to produce a low transducer output voltage. As may be seen in FIG. 8, at a no flow condition, (D2) of the first transducer is equal to (D2) of the second transducer. Therefore, as may be seen in FIG. 4, when the first and the second transducers are connected in the bridge network, and (D2) of the first transducer is equal to (D2) of the second transducer, then, the electrical potential at points 94 and 95 will be the same. An meter connected between this points, will therefore show a zero reading. An additional shift in phase may occur dur to changes in the temperature between the wave emitting and the wave reflecting surface. Since the velocity of sound through air, varies with changes in air temperature, a temperature variation within the transducer will result in a sound velocity dependent shift in phase, either leading, or lagging, depending on the change in temperature. The diagram shows, an increase in the velocity of sound as a consequence of increased temperature between the wave emitting and the wave reflecting surface. Thereby, causing the additional shift in phase as indicated by the dotted line, which changes the dimensions (D1), to (C1), and (D2), to (C2). The additional sound velocity dependent shift in phase, causes the electrical impedance of the piezoelectric element to increase, and inversely to produce a lower transducer output voltage. The second transducer output voltage (V) will therefore follow any change in temperature between the wave emitting, and the wave reflecting surface.
In operation, both piezoelectric ceramic elements are driven by the same oscillator. Hence, both transducers will produce a coincidental propagation of acoustic waves, in step with the oscillator frequency, while serving independent functions. The independent functions of the first transducer 57 and second transducer 59 each, will produce an electric output of a different magnitude. Both, the first and the second transducer are therefore electrically connected, so as to provide a single electric output equivalent to both, the first, and second function.
FIG. 4 shows the electric circuit of the device in FIG. 3, wherein a single electronic oscillator receives driving current from a power supply not shown, to generate an alternating current of fixed frequency and amplitude. The oscillator is in line connected with resistors R1 and R2, capacitors C1 and C2, and the piezoelectric ceramic elements 92 and 93 to ground. Thereby forming a bridge network, wherein the electric output signal is provided at terminals 94 and 95, which may be connected to either a volt meter, or an automobile on-board electronic computer for controlling the incorporated fuel injection system.
FIG. 5, represents another alternate embodiment of the present invention, in which for reason of simplicity the housing upper portion 99 above line A-A is not described, since except for the concentrically within said upper housing portion disposed ultrasonic generator sub-assembly 100 having emitter element 102 and the input leads 103 and 104, all other parts are in all respects identical to housing portion 12 in FIG. 1. In FIG. 5, the arrangement of the upper housing portion 99, the annular second housing portion 105, and cup 106 are securely held together by the set of suitable screws 107 extending through the longitudinal apertures of flange 108, and housing portion 105 to be in threaded engagement with the internally threaded aperture 109 of end cup 106. A longitudinally flexible diaphragm 110 is securely held in a concentrically disposed position, and is hermetically sealed at its periphery 111, by being squeezed between the radially extending end wall 112 of housing portion 105, and the radially extending end wall 113 of end cup 106 so as to form the internal cavity 114 which via aperture 115, is in a fluid communicative relationship with the suction port of the venturi tube. A disk like member 116 is concentrically fixed by suitable means to center 117 of diaphragm 110, so as to bear a coaxial thereto fixed, ultrasonic receiver sub-assembly 118 having the output leads 119 and 120, and the receiver element 121 which possesses the same inhered, natural frequency, as does the emitter element 102. In operation, an electronic oscillator provides the piezoelectric ceramic emitter element 102 with an alternating driving current of sinusoidal, or square wave configuration, at a fixed frequency and fixed amplitude. Thereby exciting the emitter element to vibrate at the oscillator frequency. The mechanical vibrations generate, and propagate acoustic energy in form of wave motion at oscillator frequency and fixed amplitude, which is received by element 121.
Referring now to FIG. 10. Since the emitting, and the receiving piezoelectric elements in FIG. 5 possesses equal natural resonance frequencies, the impingement of the emitted waves on the receiving element produces the highest achievable resonance, when the receiving surface is positioned at nose (A); which in turn, produces, the highest achievable transducer output voltage. To obtain a gain in the volumetric flow rate dependent output voltage, the receiving surface of the piezoelectric element must be located at position (D), where, due to high antiresonance, and corresponding high impedance, the transducer produces a substantially lower output voltage. Therefore, any movement of the wave reflecting surface (R) from position (D) toward node (A) due to increase in suction pressure within cavity 114, causes an increase in transducer output voltage at a rate, proportional to the volumetric rate of air flow through the venturi tube. In addition, changes in air density, due to fluctuations in air temperature may change the transducer volumetric flow rate dependent output, either to a higher, or to a lower voltage. That is to say, a decrease in the temperature causes an increase in air density, and visa versa as the case may be. Since the velocity of sound in air increases with increasing temperature, the propagated wave undergoes the leading shift in phase, from (a1), to (a2). As may be seen in the diagram, the shift in phase, causes antiresonance to increase from (b1), to (b2), accompanied by increased electrical impedance of the piezoelectric element, and inversely by lowering the transducer output voltage as indicated by (V1). Any change in the distance between the emitting and the receiving element from position (D) to position (E) causes the lowering of antiresonance, accompanied by the lowering in impedance, and inversely by the increase of transducer output voltage. Therefore, the transducer output voltage (V2) represents the mass flow rate of air.
FIG. 6 shows another alternate embodiment of the present invention, consisting of the venturi tube having the constriction 126. The upper housing portion 127a is securely fixed by screws 128 to the venturi housing 127b, so as to form the cavity 129. For purpose of venting cavity 129, to equalize the cavity internal pressure with pressure encountered before and after the venturi constriction, the cavity is fluid communicative connected via aperture 130 just upstream, and via aperture 131 just downstream of the venturi throat 132. To vent the interior of cavity 129, aperture 133 connects the venturi throat 132 fluid communicative with the interior of the flexible capsule element 134. The capsule element having concentrically thereto disposed, the wave deflecting member 135. The housing portion 127a comprises concentrically within disposed, the ultrasonic transducer sub-assembly 136 having the emitter-receiver element 137 and electric leads 138 and 139. In principle, the integrally constructed venturi-acoustical transducer device operates similar to the device in FIG. 1. Hence producing at leads 138 and 139 a single electric output from two independent functions. As may be seen in FIG. 6, the electronic circuit comprises the electronic oscillator 140 producing alternating current of a fixed frequency and amplitude. The oscillator output is series connected via resistor 141, and capacitor 142 to terminal 143, and via lead 138 across the ultrasonic generator 137 and lead 139 to ground. Terminal 143 is connected in series via amplifier 144, rectifier 145, digital converter 146, to computer 147. For use in automobile on-board applications in addition, a engine temperature sensor 148, throttle position sensor 149 and the distributor RPM sensor 150 are also connected to the computer 147, which correlate all input data to provide the fuel injector control unit 151 with an electric signal which is further processed by said control unit to produce an electric signal for driving the fuel injector(s) 152.
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Apparatus for obtaining the mass flow rate of engine aspirated air. An ultrasonic transducer measures the density of atmospheric air, while coincidentally measuring the velocity of air within a venturi of an engine air induction tube. The two individual measurements produce a single electric output signal proportional to the mass flow rate of air.
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BACKGROUND
The present invention relates to pest control, and more particularly to monitoring termite activity proximate and especially under building structures.
Termite infestation and damage is a continuing problem in buildings having wood structure. Traditionally, the structures are inspected only infrequently, such as in connection with a sale, at which time considerable damage may have been done, with expensive repairs being required. Termite infestation and damage is generally not readily apparent, and partial dismantling of building structures in order to locate possible infestation has to be weighed against the damage done by such dismantling and the cost of restoration. Even professional inspections are not always effective with respect to inaccessible structure.
Accordingly, various non-invasive devices have been developed for detecting termite activity, such devices being implanted in the ground around and/or under homes or other building structures. For example, U.S. Pat. No. 5,329,726 to Thorne et al. and U.S. Pat. No. 5,901,496 to Woodruff disclose ground-implantable devices for detecting termite activity, the devices having a perforate outer housing for permanent ground implantation, and a removable perforate cartridge having bait therein. The cartridge is removed and visually inspected for detection of termite activity. These devices of the prior art exhibit a number of disadvantages; for example:
1. They are ineffective in that active termite infestations may be ignored because:
a. the unit does not get proper inspections;
b. the original placement of the unit is difficult to determine;
c. an aggressive termite colony was not identified early; and
2. They are difficult to install and monitor, especially when implanted in crawl space under structures.
Thus there is a need for a device that facilitates detection and monitoring of infestation of soil environments of building structures by destructive organisms, that is both effective and easy to use, and that is inexpensive to provide.
SUMMARY
The present invention meets this need by providing a monitoring device having a direct indication of a predetermined amount of cumulative destructive activity of invasive organisms such as termites. In one aspect of the invention, an apparatus for signaling a cumulative amount of weakening of a test material resulting from exposure to a hazardous environment includes a body; a test element supported relative to the body and comprising the test material; means for controllably exposing the test element to the hazardous environment; means for applying a load force to the test element, the load force being effective for displacing a portion of the test element when there is a predetermined amount of weakening of the test element; a flag member movably supported relative to the body and coupled to the test element for movement in projecting relation to the body when the test element is weakened to the predetermined amount. The means for controllably exposing can include the body having a cavity for enclosing the test element, a side wall of the body having an opening therein for communicating with the hazardous environment. As used herein “hazardous environment” means an environment that may be deleterious to the strength of a structural material.
In another aspect of the invention, an apparatus for detecting the presence and eating activity of organisms that damage structures by consuming portions thereof includes the body; a bait element supported relative to the body and comprising a consumable structural material; means for controllably exposing the bait element to the organisms; means for applying a load force to the bait element, the load force being effective for displacing a portion of the bait element when there is a predetermined amount of weakening of the bait element; a flag member movably supported relative to the body and coupled to the bait element for movement in projecting relation to the body when the bait element is weakened to the predetermined amount by the organisms.
The exposing means can include the body having a cavity for enclosing the bait element, a side wall of the body having an entrance passage formed therein for admitting the organisms. Preferably the exposing means further includes a barrier member covering the entrance passage and being formed of a sheet of consumable porous material for excluding foreign material from the entrance passage. The consumable material of the barrier member is preferably perforated for enhanced communication of bait odor out of and of the organisms into the entrance passage. The barrier member can also act as an attractant, being selected, for example, from the group consisting of balsa wood, pine, and cardboard. Preferably the body has an outer portion to which the sheet of consumable porous material is connected and a telescopically separable core portion that supports the bait element and the flag member for facilitating removal and inspection of the bait element without disturbing the outer body and the sheet of porous material.
The entrance passage can extend between a first opening in an outside surface of the side wall and a second opening in an inside surface of the side wall, the first opening having a first area, the second opening having a second area being preferably less than the first area, the passage smoothly tapering between the first area and the second area for concentrating eating activity at a specific location along the bait element. The body can form an elongate housing having respective bottom and top extremities, the entrance passage being preferably one of a vertically spaced plurality of entrance passages for exposure to organisms at plural depths within the hazardous environment, a consumable porous barrier member covering each of the entrance passages. The entrance passages and the barrier member can be on a first fade of the body, the body preferably including a second face having counterparts of the entrance passages and the barrier member for exposing the bait element to organisms approaching from different directions.
The means for applying a load force can include a first coupling for anchoring one end to the bait element to the body, a second coupling for connecting an opposite end of the bait element, and a spring for applying tensile load to the bait element through the second coupling. The flag member can be connected to the second coupling. The bait element can be a wood member having a bait substance applied thereto.
In a further aspect of the invention, a method for monitoring a predetermined cumulative eating activity of organisms on a bait member includes:
(a) providing a housing body having an elongate cavity and a side wall passage;
(b) anchoring one end of the bait member to the body with the bait member extending within the cavity;
(c) connecting a flag member to an opposite end of the bait member with the flag member extending to proximate a flag opening of the body;
(d) connecting a spring member between the flag member and the housing body for tensioning the bait member;
(e) placing the housing body in a medium subject to infestation by the organisms with the side wall passage being accessible by the organisms and the flag opening being located outside the medium; and
(f) periodically observing the housing body for display to the flag member in an extended position thereof.
The method can further include interposing a consumable porous barrier between the medium and the side wall passage for preventing the medium from contacting the bait member.
DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings, where:
FIG. 1 is a side view of a termite monitoring apparatus according to the present invention;
FIG. 2 is a top view of the apparatus of FIG. 1;
FIG. 3 is a lateral sectional view on line 3 — 3 of FIG. 1; and
FIG. 4 is a plan sectional view on line 4 — 4 of FIG. 1 .
DESCRIPTION
The present invention is directed to a device and method for detecting and monitoring the activity of invasive destructive organisms such as termites. With reference to FIGS. 1-4 of the drawings, a monitoring apparatus 10 includes a generally cylindrical housing body 12 having an elongate main cavity 14 for receiving a test element 16 , a plurality of entrance passages 18 being formed in one or more side walls 20 of the body 12 for admitting the organisms (not shown). The test element 16 is typically in the form of a cardboard strip or rod, wooden rod or dowel, which can be impregnated or coated with a suitable attractant such as phermone, the element 16 thus also being sometimes referred to herein as a bait element. A stop member 22 is attached at a bottom extremity of the bait element 16 for anchoring engagement proximate a lower extremity of the main cavity 14 . Also, a flag member 24 is connected to a top extremity of the bait element 16 by a flag fitting 26 , the flag member 24 being axially movable from a first position as shown by solid lines to a second position as shown by broken lines in FIG. 3 . The flag member 24 extends within a flag cavity 28 that forms an enlargement of the main cavity 14 , the cavity 28 extending to the top of the housing body 12 . An upper portion of the flag cavity 28 is enlarged, forming a spring cavity 30 for accommodating a stop ring 32 that projects laterally from the flag member, and a compression spring 34 that is interposed between the stop ring and a bottom extremity of the spring cavity 30 for biasing the flag member toward the second position thereof, the stop ring 32 abutting a main cap 54 (further described below) that forms an upper extremity of the spring cavity 30 in the second position of the flag member 24 . Thus, when a predetermined amount of weakening of the test element 16 occurs, the element fractures in tension, whereupon the flag member 24 snaps to the second position thereof in projecting relation to the housing body 12 , being viewable from a distance as a direct indication of the corresponding cumulative consumption of the element 16 .
The stop member 22 and the flag fitting 26 can be attached to the test element 16 by any suitable means, such as by an adhesive, and/or by a coupling pin (not shown) that projects laterally through the element 16 and opposite walls of the stop member (and the flag fitting). As shown in FIG. 3, the stop member 22 is retained against upward movement by an anchor ledge 36 that projects inwardly within the main cavity 14 of the body 12 .
A preferred configuration of the entrance passages 18 has each passage formed with a large outwardly facing first opening 38 and a much smaller second opening 40 into the main cavity 14 , the passage 18 being smoothly inwardly tapered from a first area corresponding to the first opening 38 to a second area corresponding to the second opening 40 for focusing invasive activity at a particular location along the test element 16 .
A principal feature of the present invention is that each entrance passage 18 is covered by a porous barrier member 42 that is easily consumed by invasive organisms seeking access to the bait element 16 after the apparatus 10 is imbedded in soil that may contain the organisms. Thus the first openings 38 of the entrance passages 18 can be quite large without being blocked by pebbles or clods of the soil. More particularly, it is expected that the invading organisms will not entirely consume the portions of the barrier member 42 that cover the first openings 38 , the barrier member being at least partially effective in excluding the soil particles from the entrance passages 18 . Further, the soil particles that do get in the passages are likely to fall below the second openings 40 without blocking them. Moreover, the enhanced area of the first openings 38 serves to enable the passage of gaseous attractant matter through the porous barrier member 42 at a rate at least as great as that permitted by the smaller area of the second openings 40 . As shown in FIG. 1, each of the first openings 38 can have a rounded rectangular of other non-circular shape for more fully utilizing the area of the side walls 20 of the body 12 . Further, the barrier members are preferably perforated as indicated at 43 for enhanced communication of gaseous attractant into the soil, and for facilitating entry of termites or other invasive organisms. As best shown in FIG. 4, the barrier members 42 are retained in respective side walls 20 of the body 12 by pairs of flange portions 44 , the barrier members being inserted (or removed for replacement) from the top of the body 12 .
A drain opening 46 is provided at the bottom of the main cavity 14 as shown in FIG. 3 for draining moisture that might otherwise accumulate therein, the opening 46 being recessed above a bottom extremity of the housing body 12 for spacing soil therefrom when the apparatus 10 is in use. Moisture released into the soil from the opening 46 creates an environment that is attractive to termites. As shown in FIG. 4, at least a lower portion of the main cavity 12 optionally extends laterally as indicated at 12 ′ by a sufficient distance from the anchor ledge 36 for allowing the test element having the stop member 22 thereon to be lowered through the flag cavity 28 into the main cavity 14 , and moved laterally into engagement with the anchor ledge 36 , the anchor ledge 36 being open toward the enlarged cavity portion 12 ′.
Preferably the second openings 40 of the entrance passages 18 in respective side walls 20 of the body 12 are at corresponding locations along the test element 16 for further concentrating invasive activity at those locations, thereby further accelerating fracture of the test element 16 to more effectively and repeatably indicate a degree of infestation as the predetermined weakening of the test element 16 .
The apparatus 10 also includes a skirt member 48 for facilitating imbedded placement of the housing body 12 vertically oriented and at a desired depth in soil. The skirt member also collects condensation, which typically occurs between the soil and the skirt-member. The skirt member 48 is generally circular, having an outwardly and downwardly extending main portion 49 for directing the condensation away from the housing body 12 , and a downwardly projecting flange portion 50 for imparting stiffness to the skirt member, which is also formed with a central opening for passage of an upper portion of the housing body 12 . The outwardly directed condensation advantageously creates an enlarged moisture barrier around the housing 12 , thereby enhancing the attraction of termite activity to the monitor apparatus 10 .
The body 12 is formed with an outwardly projecting skirt lip 52 which rests on the skirt member 48 , the skirt member resting on the ground and being retained on the body 12 against the lip 52 by the weight of the body 12 and the other components of the apparatus 10 . A main cap 54 covers the top of the body 12 and the barrier members 42 for shedding moisture that might fall on the apparatus 10 , the main cap 54 having a central opening 55 for exposing the flag cavity 28 , the flag member 24 extending partway through the opening 55 in the first position thereof. The main cap is upwardly convex for enhancing the shedding of moisture, and for smoothly deflecting passing objects such as lawnmowers and the like that may be used in the vicinity of the apparatus 10 . The flag member 24 is exposed by extending through the main opening 55 in the second position thereof, upward movement of the flag member being limited by the stop ring 32 contacting the underside of the main cap 55 . In the exemplary configuration of the apparatus 10 as shown in the drawings, the housing body 12 is generally triangular in cross-section. Of course, there can be other numbers of the side walls 20 , with square and other polygonal cross-sectional shapes being contemplated.
Preferably the housing body 12 is separable, including a core portion 12 ′ that holds the test element 16 together with the flag member 24 and its associated hardware, the designation 12 pertaining to an outer body portion having the flange portions 44 and the lip 52 formed thereon. As shown in FIGS. 3 and 4, the first openings 38 are formed in the core portion 12 ′. Also, a bail member 56 is pivotally connected at the top of the core portion 12 ′ for facilitating removal thereof axially from the top of the body 12 when the main cap 54 is removed, the cap 54 having snap-engagement with a cap lip 58 that is spaced above the skirt lip 52 on the outer body 12 . Thus the core portion 12 ′ can be removed from the main body portion 12 and inspected without disturbing either the body 12 or the barrier members 42 that are retained thereby. As further shown in FIG. 4, the enlarged cavity potion 14 ′ can extend through a side wall 20 ′ of the core portion 12 ′, the side wall 20 ′ not having the vertically spaced entrance passages 18 formed therein. However, the main body portion 12 is provided with counterparts of the flange portions 44 and the barrier member 42 facing the side wall 20 ′. In the alternative of the housing body 12 having the core portion 12 ′ being integrally formed, the enlarged cavity portion 14 ′ can be open to the outside, being covered by one of the barrier members 42 .
Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. For example, The housing body 12 can have a generally circular cross-section, a single tubular member being substituted for the barrier members 42 . Also, the stop member 22 can be configured for snap-engagement with the anchor ledge 36 , the body 12 being formed without the enlarged cavity portion 14 ′. Therefore, the spirit and scope of the appended claims should not necessarily be limited to the description of the preferred versions contained herein.
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Apparatus, for detecting the presence and eating activity of organisms such as termites that damage structures, includes a body; a wooden bait element controllably exposed to the organisms within a cavity of the body, and having an applied bait substance; a side wall of the body having a vertically spaced plurality of smoothly converging entrance passages for admitting the organisms, a consumable porous barrier covering each of the entrance passages. Spring tension is applied to an upper end of the bait element, an opposite end being anchored to the body. A flag member that is connected to the upper end of the bait element projects from the body when the bait element is weakened to the predetermined amount by the organisms.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. application Ser. No. 15/166,185 filed May 26, 2016, a continuation-in-part of U.S. application Ser. No. 15/289,126 filed Oct. 8, 2016, a continuation-in-part of U.S. application Ser. No. 15/353,537 filed Nov. 16, 2016, a continuation-in-part of U.S. application Ser. No. 15/415,844 filed Jan. 25, 2017, a continuation-in-part of U.S. application Ser. No. 15/415,846 filed Jan. 25, 2017 and a continuation-in-part of U.S. application Ser. No. 15/462,536 filed Mar. 17, 2017. The U.S. application Ser. No. 15/166,185 claims the priority benefit of U.S. Provisional Application Ser. No. 62/166,771 filed May 27, 2015. The U.S. application Ser. No. 15/289,126 is a continuation-in-part of U.S. application Ser. No. 15/166,185 filed May 26, 2016. The U.S. application Ser. No. 15/353,537 is a continuation-in-part of U.S. application Ser. No. 15/166,185 filed May 26, 2016 and a continuation-in-part of U.S. application Ser. No. 15/289,126 filed Oct. 8, 2016. The U.S. application Ser. Nos. 15/415,844, 15/415,846 and 15/462,536 are continuation-in-part of U.S. application Ser. No. 15/166,185 filed May 26, 2016, continuation-in-part of U.S. application Ser. No. 15/289,126 filed Oct. 8, 2016 and continuation-in-part of U.S. application Ser. No. 15/353,537 filed Nov. 16, 2016. The entirety of each of said applications is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a semiconductor assembly and, more particularly, to a thermally enhanced semiconductor assembly with three dimensional integration in which a stacked semiconductor sub-assembly is wire bonded to and thermally conductible to a wiring board having a heat spreader integrated with dual wiring structures, and a method of making the same.
DESCRIPTION OF RELATED ART
[0003] Market trends of multimedia devices demand for faster and slimmer designs. One of assembly approaches is to interconnect two devices with stacking configuration so that the routing distance between the two devices can be the shortest possible. As the stacked devices can talk directly to each other with reduced latency, the assembly's signal integrity and additional power saving capability are greatly improved. However, as semiconductor devices are susceptible to performance degradation at high operational temperatures, stacking chips without proper heat dissipation would worsen devices' thermal environment and may cause immediate failure during operation.
[0004] Additionally, U.S. Pat. Nos. 8,008,121, 8,519,537 and 8,558,395 disclose various assembly structures having an interposer disposed in between the face-to-face chips. Although there is no TSV in the stacked chips, the TSV in the interposer that serves for circuitry routing between chips induces complicated manufacturing processes, high yield loss and excessive cost.
[0005] For the reasons stated above, and for other reasons stated below, an urgent need exists to provide a three dimensional semiconductor assembly that can address high packaging density, better signal integrity and high thermal dissipation requirements.
SUMMARY OF THE INVENTION
[0006] The objective of the present invention is to provide a thermally enhanced semiconductor assembly in which a stacked semiconductor sub-assembly is electrically connected to a wiring board through a plurality of bonding wires and thermal conductible to a heat spreader provided in the wiring board. The heat spreader is disposed in a through opening of a wiring structure and mechanically supported by, electrically connected with, and thermally dissipated through another wiring structure, thereby improving mechanical, thermal and electrical performances of the assembly.
[0007] In accordance with the foregoing and other objectives, the present invention provides a thermally enhanced semiconductor assembly having a stacked semiconductor sub-assembly electrically connected to a wiring board through bonding wires. The stacked semiconductor sub-assembly includes a first device, a second device and a routing circuitry. The wiring board includes a heat spreader, a first wiring structure and a second wiring structure. In a preferred embodiment, the first device is thermally conductible to the heat spreader and spaced from and electrically connected to the second device through the routing circuitry; the routing circuitry provides primary fan-out routing and the shortest interconnection distance between the first device and the second device; the first wiring structure laterally surrounds peripheral edges of the heat spreader and the sub-assembly, and is electrically coupled to the routing circuitry by bonding wires to provide further fan-out routing; and the second wiring structure covers the first wiring structure and the heat spreader to provide mechanically support, and is thermally conductible to the heat spreader and electrically coupled to the first wiring structure.
[0008] Accordingly, the present invention provides a thermally enhanced semiconductor assembly with three dimensional integration, comprising: a stacked semiconductor sub-assembly that includes a first device, a second device and a routing circuitry, wherein the first device is electrically coupled to a first surface of the routing circuitry and the second device is electrically coupled to a second surface of the routing circuitry opposite to the first surface; a wiring board that includes a first wiring structure, a second wiring structure and a heat spreader, wherein (i) the first wiring structure has a first surface, an opposite second surface, and a through opening extending from the first surface and to the second surface, (ii) the heat spreader is disposed in the through opening and has a backside surface substantially coplanar with the first surface of the first wiring structure, (iii) the second wiring structure is disposed on the backside surface of the heat spreader and the first surface of the first wiring structure and electrically connected to the first wiring structure and thermally conductible to the heat spreader through metallized vias, and (iv) the stacked semiconductor sub-assembly is disposed in the through opening; and a plurality of bonding wires that electrically couple the routing circuitry to the wiring board.
[0009] Additionally, the present invention provides a method of making a thermally enhanced semiconductor assembly with three dimensional integration, comprising: providing a stacked semiconductor sub-assembly that includes a first device, a second device and a routing circuitry, wherein the first device is electrically coupled to a first surface of the routing circuitry and the second device is electrically coupled to a second surface of the routing circuitry opposite to the first surface; providing a wiring board that includes a first wiring structure, a second wiring structure and a heat spreader, wherein (i) the first wiring structure has a first surface, an opposite second surface, and a through opening extending from the first surface to the second surface, (ii) the heat spreader is disposed in the through opening and has a backside surface substantially coplanar with the first surface of the first wiring structure, and (iii) the second wiring structure is disposed on the backside surface of the heat spreader and the first surface of the first wiring structure and electrically connected to the first wiring structure and thermally conductible to the heat spreader through metallized vias; disposing the stacked semiconductor sub-assembly in the through opening of the first wiring structure and over the heat spreader; and providing a plurality of bonding wires that electrically couple the routing circuitry and the wiring board.
[0010] Unless specifically indicated or using the term “then” between steps, or steps necessarily occurring in a certain order, the sequence of the above-mentioned steps is not limited to that set forth above and may be changed or reordered according to desired design.
[0011] The semiconductor assembly and the method of making the same according to the present invention have numerous advantages. For instance, stacking and electrically coupling the first and second devices to both opposite sides of the routing circuitry can offer the shortest interconnect distance between the first and second devices. Inserting the sub-assembly into the through opening of the first wiring structure of the wiring board is particularly advantageous as the wiring board can provide mechanical housing for the sub-assembly, whereas the heat spreader in the through opening and mechanically supported by the second wiring structure can provide thermal dissipation for the first device. Additionally, attaching the bonding wires to the sub-assembly and the wiring board can offer a reliable connecting channel for interconnecting the devices assembled in the sub-assembly to terminal pads provided in the wiring board.
[0012] These and other features and advantages of the present invention will be further described and more readily apparent from the detailed description of the preferred embodiments which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The following detailed description of the preferred embodiments of the present invention can best be understood when read in conjunction with the following drawings, in which:
[0014] FIG. 1 is a cross-sectional view of a structure with routing traces formed on a sacrificial carrier in accordance with the first embodiment of the present invention;
[0015] FIG. 2 is a cross-sectional view of the structure of FIG. 1 further provided with a dielectric layer and via openings in accordance with the first embodiment of the present invention;
[0016] FIG. 3 is a cross-sectional view of the structure of FIG. 2 further provided with conductive traces in accordance with the first embodiment of the present invention;
[0017] FIG. 4 is a cross-sectional view of the structure of FIG. 3 further provided with a first device in accordance with the first embodiment of the present invention;
[0018] FIG. 5 is a cross-sectional view of the structure of FIG. 4 further provided with a molding compound in accordance with the first embodiment of the present invention;
[0019] FIG. 6 is a cross-sectional view of the structure of FIG. 5 after removal of the sacrificial carrier in accordance with the first embodiment of the present invention;
[0020] FIG. 7 is a cross-sectional view of the structure of FIG. 6 further provided with a second device to finish the fabrication of a stacked semiconductor sub-assembly in accordance with the first embodiment of the present invention;
[0021] FIG. 8 is a cross-sectional view of a first wiring structure in accordance with the first embodiment of the present invention;
[0022] FIG. 9 is a cross-sectional view of the structure of FIG. 8 further provided with a heat spreader in accordance with the first embodiment of the present invention;
[0023] FIG. 10 is a cross-sectional view of the structure of FIG. 9 further provided with a second wiring structure to finish the fabrication of a wiring board in accordance with the first embodiment of the present invention;
[0024] FIG. 11 is a cross-sectional view of the structure of FIG. 10 further provided with the stacked semiconductor sub-assembly of FIG. 7 in accordance with the first embodiment of the present invention;
[0025] FIG. 12 is a cross-sectional view of the structure of FIG. 11 further provided with bonding wires to finish the fabrication of a semiconductor assembly in accordance with the first embodiment of the present invention;
[0026] FIG. 13 is a cross-sectional view of the structure of FIG. 12 further provided with an encapsulant in accordance with the first embodiment of the present invention;
[0027] FIG. 14 is a cross-sectional view of the structure of FIG. 13 further provided with a third device in accordance with the first embodiment of the present invention;
[0028] FIG. 15 is a cross-sectional view of the structure of FIG. 14 further provided with solder balls in accordance with the first embodiment of the present invention;
[0029] FIG. 16 is a cross-sectional view of the structure of FIG. 13 further provided with passive components, an additional heat spreader and solder balls in accordance with the first embodiment of the present invention;
[0030] FIG. 17 is a cross-sectional view of the inverted structure of FIG. 13 further provided with third devices, an additional heat spreader and solder balls in accordance with the first embodiment of the present invention;
[0031] FIG. 18 is a cross-sectional view of the structure of FIG. 13 further provided with an additional wiring board in accordance with the first embodiment of the present invention;
[0032] FIG. 19 is a cross-sectional view of the structure of FIG. 18 further provided with third devices and solder balls in accordance with the first embodiment of the present invention;
[0033] FIG. 20 is a cross-sectional view of the structure of FIG. 13 further provided with another aspect of the additional wiring board in accordance with the first embodiment of the present invention;
[0034] FIG. 21 is a cross-sectional view of a wiring board in accordance with the second embodiment of the present invention;
[0035] FIG. 22 is a cross-sectional view of the structure of FIG. 21 further provided with the stacked semiconductor sub-assembly of FIG. 7 in accordance with the second embodiment of the present invention;
[0036] FIG. 23 is a cross-sectional view of the structure of FIG. 22 further provided with bonding wires to finish the fabrication of a semiconductor assembly in accordance with the second embodiment of the present invention;
[0037] FIG. 24 is a cross-sectional view of the structure of FIG. 23 further provided with an encapsulant in accordance with the second embodiment of the present invention;
[0038] FIG. 25 is a cross-sectional view of the inverted structure of FIG. 24 further provided with a third device and passive components in accordance with the second embodiment of the present invention;
[0039] FIG. 26 is a cross-sectional view of the inverted structure of FIG. 25 further provided with an encapsulant in accordance with the second embodiment of the present invention;
[0040] FIG. 27 is a cross-sectional view of the inverted structure of FIG. 26 further provided with solder balls in accordance with the second embodiment of the present invention;
[0041] FIG. 28 is a cross-sectional view of the structure with a stacked semiconductor sub-assembly attached to the wiring board of FIG. 10 in accordance with the third embodiment of the present invention;
[0042] FIG. 29 is a cross-sectional view of the structure of FIG. 28 further provided with bonding wires in accordance with the third embodiment of the present invention;
[0043] FIG. 30 is a cross-sectional view of the structure of FIG. 29 further provided with vertical connecting elements in accordance with the third embodiment of the present invention;
[0044] FIG. 31 is a cross-sectional view of the structure of FIG. 30 further provided with an encapsulant to finish the fabrication of a semiconductor assembly in accordance with the third embodiment of the present invention;
[0045] FIG. 32 is a cross-sectional view of the structure of FIG. 31 further provided with a third device in accordance with the third embodiment of the present invention;
[0046] FIG. 33 is a cross-sectional view of the structure of FIG. 32 further provided with solder balls in accordance with the third embodiment of the present invention;
[0047] FIG. 34 is a cross-sectional view of another aspect of the semiconductor assembly in accordance with the third embodiment of the present invention;
[0048] FIG. 35 is a cross-sectional view of yet another aspect of the semiconductor assembly in accordance with the third embodiment of the present invention;
[0049] FIG. 36 is a cross-sectional view of a stacked semiconductor sub-assembly in accordance with the fourth embodiment of the present invention;
[0050] FIG. 37 is a cross-sectional view of the structure with the sub-assembly of FIG. 36 wire bonded to the wiring board 30 of FIG. 10 in accordance with the fourth embodiment of the present invention;
[0051] FIG. 38 is a cross-sectional view of the structure of FIG. 37 further provided with an encapsulant in accordance with the fourth embodiment of the present invention;
[0052] FIG. 39 is a cross-sectional view of the structure of FIG. 38 further provided with a third device in accordance with the fourth embodiment of the present invention;
[0053] FIG. 40 is a cross-sectional view of the inverted structure of FIG. 38 further provided with third devices, a heat spreader and solder balls in accordance with the fourth embodiment of the present invention;
[0054] FIG. 41 is a cross-sectional view of a semiconductor assembly in accordance with the fifth embodiment of the present invention;
[0055] FIG. 42 is a cross-sectional view of the structure of FIG. 41 further provided with a third device and solder balls in accordance with the fifth embodiment of the present invention;
[0056] FIG. 43 is a cross-sectional view of the structure of FIG. 41 further provided with a lens and solder balls in accordance with the fifth embodiment of the present invention;
[0057] FIG. 44 is a cross-sectional view of a semiconductor assembly in accordance with the sixth embodiment of the present invention;
[0058] FIG. 45 is a cross-sectional view of the structure of FIG. 44 further provided with a third device and solder balls in accordance with the fifth embodiment of the present invention; and
[0059] FIG. 46 is a cross-sectional view of the structure of FIG. 44 further provided with a lens and solder balls in accordance with the sixth embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0060] Hereafter, examples will be provided to illustrate the embodiments of the present invention. Advantages and effects of the invention will become more apparent from the following description of the present invention. It should be noted that these accompanying figures are simplified and illustrative. The quantity, shape and size of components shown in the figures may be modified according to practical conditions, and the arrangement of components may be more complex. Other various aspects also may be practiced or applied in the invention, and various modifications and variations can be made without departing from the spirit of the invention based on various concepts and applications.
Embodiment 1
[0061] FIGS. 1-12 are schematic views showing a method of making a semiconductor assembly that includes a routing circuitry 21 , a first device 22 , a molding compound 25 , a second device 27 , a wiring board 30 and bonding wires 41 in accordance with the first embodiment of the present invention.
[0062] FIG. 1 is a cross-sectional view of the structure with routing traces 212 formed on a sacrificial carrier 10 . The sacrificial carrier 10 typically is made of copper, aluminum, iron, nickel, tin, stainless steel, silicon, or other metals or alloys, but any other conductive or non-conductive material also may be used. In this embodiment, the sacrificial carrier 10 is made of an iron-based material. The routing traces 212 typically are made of copper and can be pattern deposited by numerous techniques, such as electroplating, electroless plating, evaporating, sputtering or their combinations, or be thin-film deposited followed by a metal patterning process. For a conductive sacrificial carrier 10 , the routing traces 212 are deposited typically by plating of metal. The metal patterning techniques include wet etching, electro-chemical etching, laser-assist etching, and their combinations with an etch mask (not shown) thereon that defines the routing traces 212 .
[0063] FIG. 2 is a cross-sectional view of the structure with a dielectric layer 215 on the sacrificial carrier 10 as well as the routing traces 212 and via openings 216 in the dielectric layer 215 . The dielectric layer 215 is deposited typically by lamination or coating, and contacts and covers and extends laterally on the sacrificial carrier 10 and the routing traces 212 from above. The dielectric layer 215 typically has a thickness of 50 microns, and can be made of epoxy resin, glass-epoxy, polyimide, or the like. After the deposition of the dielectric layer 215 , the via openings 216 are formed by numerous techniques, such as laser drilling, plasma etching and photolithography, and typically have a diameter of 50 microns. Laser drilling can be enhanced by a pulsed laser. Alternatively, a scanning laser beam with a metal mask can be used. The via openings 216 extend through the dielectric layer 215 and are aligned with selected portions of the routing traces 212 .
[0064] Referring now to FIG. 3 , conductive traces 217 are formed on the dielectric layer 215 by metal deposition and metal patterning process. The conductive traces 217 extend from the routing traces 212 in the upward direction, fill up the via openings 216 to form metallized vias 218 in direct contact with the routing traces 212 , and extend laterally on the dielectric layer 215 . As a result, the conductive traces 217 can provide horizontal signal routing in both the X and Y directions and vertical routing through the via openings 216 and serve as electrical connections for the routing traces 212 .
[0065] The conductive traces 217 can be deposited as a single layer or multiple layers by any of numerous techniques, such as electroplating, electroless plating, evaporating, sputtering, or their combinations. For instance, they can be deposited by first dipping the structure in an activator solution to render the dielectric layer 215 catalytic to electroless copper, and then a thin copper layer is electroles sly plated to serve as the seeding layer before a second copper layer is electroplated on the seeding layer to a desirable thickness. Alternatively, the seeding layer can be formed by sputtering a thin film such as titanium/copper before depositing the electroplated copper layer on the seeding layer. Once the desired thickness is achieved, the plated layer can be patterned to form the conductive traces 217 by any of numerous techniques such as wet etching, electro-chemical etching, laser-assist etching, or their combinations, with an etch mask (not shown) thereon that defines the conductive traces 217 .
[0066] At this stage, the formation of a routing circuitry 21 on the sacrificial carrier 10 is accomplished. In this illustration, the routing circuitry 21 is a multi-layered buildup circuitry and includes routing traces 212 , a dielectric layer 215 and conductive traces 217 .
[0067] FIG. 4 is a cross-sectional view of the structure with a first device 22 electrically coupled to the routing circuitry 21 . The first device 22 can be electrically coupled to the conductive traces 217 of the routing circuitry 21 using first bumps 223 in contact with the first device 22 and the first routing circuitry 21 by thermal compression, solder reflow or thermosonic bonding. In this example, the first device 22 is illustrated as a semiconductor chip.
[0068] FIG. 5 is a cross-sectional view of the structure with a molding compound 25 on the routing circuitry 21 and around the first device 22 by, for example, resin-glass lamination, resin-glass coating or molding. The molding compound 25 covers the routing circuitry 21 from above and surrounds and conformally coats and covers sidewalls of the first device 22 . As an alternative, the step of providing the molding compound 25 may be omitted.
[0069] FIG. 6 is a cross-sectional view of the structure after removal of the sacrificial carrier 10 . The sacrificial carrier 10 can be removed to expose the routing circuitry 21 from below by numerous techniques, such as wet chemical etching using acidic solution (e.g., ferric chloride, copper sulfate solutions), or alkaline solution (e.g., ammonia solution), electro-chemical etching, or mechanical process such as a drill or end mill followed by chemical etching. In this embodiment, the sacrificial carrier 10 made of an iron-based material is removed by a chemical etching solution that is selective between copper and iron so as to prevent the copper routing traces 212 from being etched during removal of the sacrificial carrier 10 .
[0070] FIG. 7 is a cross-sectional view of the structure with a second device 27 electrically coupled to the routing circuitry 21 . The second device 27 can be electrically coupled to the routing traces 212 of the routing circuitry 21 using second bumps 273 in contact with the second device 27 and the routing circuitry 21 by thermal compression, solder reflow or thermosonic bonding. In this example, the second device 27 is illustrated as a semiconductor chip. However, in some cases, the second device 27 may be a packaged device or a passive component.
[0071] At this stage, a stacked semiconductor sub-assembly 20 is accomplished and includes a routing circuitry 21 , a first device 22 , a molding compound 25 , and a second device 27 . The first device 22 and the second device 27 are electrically coupled to first and second surfaces 201 , 202 of the routing circuitry 21 , respectively, and the molding compound 25 is disposed over the first surface 201 and laterally surrounds the first device 22 .
[0072] FIG. 8 is a cross-sectional view of a first wiring structure 31 . The first wiring structure 31 has a through opening 315 extending from its first surface 311 to its second surface 312 . In this illustration, the first wiring structure 31 includes an interconnect substrate 32 , a first buildup circuitry 33 and a second buildup circuitry 34 . The interconnect substrate 32 includes a core layer 321 , a first routing layer 323 , a second routing layer 324 and metallized through vias 327 . The first routing layer 323 and the second routing layer 324 respectively extend laterally on both sides of the core layer 321 , and metallized through vias 327 extend through the core layer 321 to provide electrical connections between the first routing layer 323 and the second routing layer 324 . The first buildup circuitry 33 and the second buildup circuitry 34 are respectively disposed on both sides of the interconnect substrate 32 , and each of them includes a dielectric layer 331 , 341 and conductive traces 333 , 343 . The dielectric layers 331 , 341 respectively cover both sides of the interconnect substrate 32 from below and above, and can be made of epoxy resin, glass-epoxy, polyimide, or the like. The conductive traces 333 , 343 respectively extend laterally on the dielectric layers 331 , 341 , and include metallized vias 334 , 344 in the dielectric layers 331 , 341 . The metallized vias 334 , 344 contact the first and second routing layers 323 , 324 of the interconnect substrate 32 , and extend through the dielectric layers 331 , 341 .
[0073] FIG. 9 is a cross-sectional view of the structure with a heat spreader 35 disposed in the through opening 315 of the first wiring structure 31 . The heat spreader 35 can be a thermally conductive layer made of, for example, metal, alloy, silicon, ceramic or graphite. In this embodiment, the heat spreader 35 is a metal layer and has a backside surface 351 substantially coplanar with the first surface 311 of the first wiring structure 31 from below.
[0074] FIG. 10 is a cross-sectional view of the structure with a second wiring structure 36 formed on the backside surface 351 and the first surface 311 of the first wiring structure 31 . In this illustration, the second wiring structure 36 is a multi-layered buildup circuitry without a core layer, and includes multiple dielectric layers 361 and conductive traces 363 in an alternate fashion. The conductive traces 363 extend laterally on the dielectric layers 361 and include metallized vias 364 in the dielectric layers 361 . Accordingly, the second wiring structure 36 can be electrically coupled to the first wiring structure 31 and the heat spreader 35 through the metallized vias 364 embedded in the dielectric layers 361 and in contact with the first routing layer 323 and the heat spreader 35 .
[0075] At this stage, a wiring board 30 is accomplished and includes a first wiring structure 31 , a heat spreader 35 and a second wiring structure 36 . As the depth of the through opening 315 is more than the thickness of the heat spreader 35 , the exterior surface of the heat spreader 35 and the sidewall surface of the through opening 315 of the first wiring structure 31 forms a cavity 316 in the through opening 315 of the first wiring structure 31 . As a result, the heat spreader 35 can provide thermal dissipation for a device accommodated in the cavity 316 , whereas the combination of the first wiring structure 31 and the second wiring structure 36 offers electrical contacts for next connection from two opposite sides of the wiring board 30 .
[0076] FIG. 11 is a cross-sectional view of the structure with the stacked semiconductor sub-assembly 20 of FIG. 7 attached to the wiring board 30 of FIG. 10 . The stacked semiconductor sub-assembly 20 is aligned with and disposed in the through opening 315 of the first wiring structure 31 , with the first device 22 attached to the heat spreader 35 of the wiring board 30 using a thermally conductive material 39 . The thermally conductive material 39 can be a solder (e.g., AuSn) or a silver/epoxy adhesive. The interior sidewalls of the through opening 315 laterally surround and are spaced from peripheral edges of the stacked semiconductor sub-assembly 20 . As a result, a gap 317 is left in the through opening 315 between the peripheral edges of the stacked semiconductor sub-assembly 20 and the interior sidewalls of the first wiring structure 31 . The gap 317 laterally surrounds the stacked semiconductor sub-assembly 20 and is laterally surrounded by the first wiring structure 31 .
[0077] FIG. 12 is a cross-sectional view of the structure with bonding wires 41 attached to the stacked semiconductor sub-assembly 20 and the wiring board 30 typically by gold or copper ball bonding, or gold or aluminum wedge bonding. The bonding wires 41 contact and are electrically coupled to the routing traces 212 of the routing circuitry 21 and the conductive traces 343 of the first wiring structure 31 . As a result, the bonding wires 41 can electrically couple the routing circuitry 21 to the first wiring structure 31 .
[0078] Accordingly, as shown in FIG. 12 , a semiconductor assembly 110 is accomplished and includes a stacked semiconductor sub-assembly 20 electrically connected to a wiring board 30 by bonding wires 41 . In this illustration, the stacked semiconductor sub-assembly 20 includes a routing circuitry 21 , a first device 22 , a molding compound 25 and a second device 27 , whereas the wiring board 30 includes a first wiring structure 31 , a heat spreader 35 and a second wiring structure 36 .
[0079] The first device 22 is flip-chip electrically coupled to the routing circuitry 21 from one side of the routing circuitry 21 and enclosed by the molding compound 25 and the heat spreader 35 . The second device 27 is flip-chip electrically coupled to the routing circuitry 21 from the other side of the routing circuitry 21 and face-to-face connected to the first device 22 through the routing circuitry 21 . As such, the routing circuitry 21 offers primary fan-out routing and the shortest interconnection distance between the first device 22 and the second device 27 . The heat spreader 35 of the wiring board 30 is thermally conductible to and covers the first device 22 from below. The first wiring structure 31 laterally surrounds peripheral edges of the stacked semiconductor sub-assembly 20 and the heat spreader 35 , and is electrically coupled to the routing circuitry 21 by the bonding wires 41 . The second wiring structure 36 covers the first wiring structure 31 and the heat spreader 35 from below, and is electrically coupled to the first wiring structure 31 and thermally conductible to the heat spreader 35 through metallized vias 364 . As a result, the routing circuitry 21 , the first wiring structure 31 and the second wiring structure 36 can provide staged fan-out routing for the first device 22 and the second device 27 .
[0080] FIG. 13 is a cross-sectional view of the semiconductor assembly 110 of FIG. 12 further provided with an encapsulant 51 . The encapsulant 51 covers the bonding wires 41 and the stacked semiconductor sub-assembly 20 as well as selected portions of the wiring board 30 from above, and further fills up the gap 317 between the peripheral edges of the stacked semiconductor sub-assembly 20 and the interior sidewalls of the wiring board 30 .
[0081] FIG. 14 is a cross-sectional view of the semiconductor assembly 110 of FIG. 13 further provided with a third device 61 stacked over the stacked semiconductor sub-assembly 20 and the first wiring structure 31 of the wiring board 30 . The third device 61 can be a ball grid array package or a bumped chip, and is electrically coupled to the conductive traces 343 of the first wiring structure 31 through solder balls 71 .
[0082] FIG. 15 is a cross-sectional view of the semiconductor assembly 110 of FIG. 14 further provided with solder balls 73 . The solder balls 73 are mounted on the second wiring structure 36 of the wiring board 30 for external connection.
[0083] FIG. 16 is a cross-sectional view of the semiconductor assembly 110 of FIG. 13 further provided with passive components 65 and a heat spreader 81 at the first wiring structure 31 and solder balls 73 at the second wiring structure 36 . The passive components 65 are electrically coupled to the conductive traces 343 of the first wiring structure 31 . The heat spreader 81 has a cavity 811 and is mounted on the first wiring structure 31 and electrically coupled to the conductive traces 343 of the first wiring structure 31 for ground connection by solder balls 75 . The second device 27 is accommodated in the cavity 811 of the heat spreader 81 and thermally conductible to the heat spreader 81 by a thermally conductive material 89 in contact with the second device 27 and the heat spreader 81 . The solder balls 73 are mounted on the conductive traces 363 of the second wiring structure 36 for external connection.
[0084] FIG. 17 is a cross-sectional view of the inverted semiconductor assembly 110 of FIG. 13 further provided with third devices 61 and a heat spreader 81 at the second wiring structure 36 and solder balls 73 at the first wiring structure 31 . The third devices 61 can be ball grid array packages or bumped chips accommodated in a cavity 811 of the heat spreader 81 , and are electrically coupled to the conductive traces 363 of the second wiring structure 36 by solder balls 71 . The heat spreader 81 is thermally conductive to the third devices 61 using a thermally conductive material 89 , and electrically coupled to the conductive traces 363 of the second wiring structure 36 by solder balls 75 . The solder balls 73 are mounted on the conductive traces 343 of the first wiring structure 31 for external connection.
[0085] FIG. 18 is a cross-sectional view of the semiconductor assembly 110 of FIG. 13 further provided with an additional wiring board 90 . The wiring board 90 is stacked over the stacked semiconductor sub-assembly 20 and the wiring board 30 , and includes a third wiring structure 91 , a heat spreader 95 and a fourth wiring structure 96 . In this illustration, both the third wiring structure 91 and the fourth wiring structure 96 are multi-layered buildup circuitries without a core layer, and each includes multiple dielectric layers 911 , 961 and conductive traces 913 , 963 in an alternate fashion to provide electrical contacts at two opposite sides of the wiring board 90 . The third wiring structure 91 has a through opening 915 extending from its first surface 911 to its second surface 912 , and is electrically coupled to the conductive traces 343 of the first wiring structure 31 by solder balls 71 . The heat spreader 95 is disposed in the through opening 915 of the third wiring structure 91 , and has a backside surface 952 substantially coplanar with the second surface 912 of the third wiring structure 91 . The second device 27 is attached to and thermally conductible to the heat spreader 95 by a thermally conductive material 99 and laterally surrounded by the third wiring structure 91 . The fourth wiring structure 96 is disposed on the second surface 912 of the third wiring structure 91 and the backside surface 952 of the heat spreader 95 , and includes metallized vias 964 embedded in the dielectric layer 961 and in contact with the conductive traces 913 of the third wiring structure 91 and the heat spreader 95 .
[0086] FIG. 19 is a cross-sectional view of the semiconductor assembly 110 of FIG. 18 further provided with third devices 61 at the fourth wiring structure 96 and solder balls 73 at the second wiring structure 36 . The third devices 61 can be ball grid array packages or a bumped chips, and are stacked over and electrically coupled to the conductive traces 963 of the fourth wiring structure 96 through solder balls 77 . The solder balls 73 are mounted on the conductive traces 363 of the second wiring structure 36 for external connection.
[0087] FIG. 20 is a cross-sectional view of the semiconductor assembly 110 of FIG. 13 further provided with another aspect of the additional wiring board 90 . The wiring board 90 is similar to that illustrated in FIG. 18 , except that the third wiring structure 91 is an interconnect substrate that includes a core layer 921 , a first routing layer 923 , a second routing layer 924 , and metallized through vias 927 . The first routing layer 923 and the second routing layer 924 are disposed on opposite sides of the core layer 921 . The metallized through vias 927 extend through the core layer 921 and are electrically coupled to the first routing layer 923 and the second routing layer 924 . The fourth wiring structure 96 includes metallized vias 964 in contact with the second routing layer 924 of the third wiring structure 91 and the heat spreader 95 .
Embodiment 2
[0088] FIGS. 21-24 are schematic views showing a method of making a semiconductor assembly with the stacked semiconductor sub-assembly laterally surrounded by metallized sidewalls of the cavity of the wiring board in accordance with the second embodiment of the present invention.
[0089] For purposes of brevity, any description in Embodiment 1 above is incorporated herein insofar as the same is applicable, and the same description need not be repeated.
[0090] FIG. 21 is a cross-sectional view of a wiring board 30 . The wiring board 30 is similar to that illustrated in FIG. 10 , except that (i) it further includes a metal layer 37 that completely covers sidewalls of the through opening 315 of the first wiring structure 31 and contacts the heat spreader 35 , and (ii) the outmost conductive traces 363 of the second wiring structure 36 includes a thermal pad 366 . In this illustration, the exterior surface of the heat spreader 35 and the lateral surface of the metal layer 37 forms a cavity 316 in the through opening 315 of the first wiring structure 31 .
[0091] FIG. 22 is a cross-sectional view of the structure with the stacked semiconductor sub-assembly 20 of FIG. 7 attached to the wiring board 30 of FIG. 21 . The stacked semiconductor sub-assembly 20 is disposed in the cavity 316 of the wiring board 30 and attached to the heat spreader 35 using a thermally conductive material 39 .
[0092] FIG. 23 is a cross-sectional view of the structure with bonding wires 41 attached to the stacked semiconductor sub-assembly 20 and the wiring board 30 . The bonding wires 41 contact and are electrically coupled to the routing traces 212 of the routing circuitry 21 and the conductive traces 343 of the first wiring structure 31 .
[0093] Accordingly, as shown in FIG. 23 , a semiconductor assembly 210 is accomplished and includes a stacked semiconductor sub-assembly 20 electrically connected to a wiring board 30 by bonding wires 41 . In this illustration, the stacked semiconductor sub-assembly 20 includes a routing circuitry 21 , a first device 22 , a molding compound 25 and a second device 27 , whereas the wiring board 30 includes a first wiring structure 31 , a heat spreader 35 , a second wiring structure 36 and a metal layer 37 .
[0094] The first device 22 and the second device 27 are disposed at two opposite sides of the routing circuitry 21 and face-to-face electrically connected to each other through the routing circuitry 21 therebetween. As such, the routing circuitry 21 offers the shortest interconnection distance between the first device 22 and the second device 27 , and provides first level fan-out routing for the first device 22 and the second device 27 . The heat spreader 35 covers the inactive surface of the first device 22 and is thermally conductible to the first device 22 , whereas the metal layer 37 surrounds peripheral edges of the stacked semiconductor sub-assembly 20 and contacts the heat spreader 35 . The first wiring structure 31 is electrically coupled to the routing circuitry 21 through bonding wires 41 . The second wiring structure 36 covers the first wiring structure 31 and the heat spreader 35 from below, and is electrically coupled to the first wiring structure 31 for signal routing and to the heat spreader 35 for ground connection through metallized vias 364 . Accordingly, the combination of the first wiring structure 31 and the second wiring structure 36 can provide second level fan-out routing for the routing circuitry 21 and electrical contacts for next-level connection, whereas the combination of the heat spreader 35 and the metal layer 37 , electrically connected to the second wiring structure 36 , provides thermal dissipation and EMI shielding for the first device 22 .
[0095] FIG. 24 is a cross-sectional view of the semiconductor assembly 210 of FIG. 23 further provided with an encapsulant 51 . The encapsulant covers the bonding wires 41 , the stacked semiconductor sub-assembly 20 as well as selected portions of the first wiring structure 31 from above, and further fills up a gap 317 between the peripheral edges of the stacked semiconductor sub-assembly 20 and the interior sidewalls of the wiring board 30 .
[0096] FIG. 25 is a cross-sectional view of the inverted semiconductor assembly 210 of FIG. 24 further provided with a third device 61 and passive components 65 . The third device 61 is illustrated as a semiconductor chip, and is attached on the thermal pad 366 of the second wiring structure 36 and electrically coupled to the conductive traces 363 of the second wiring structure 36 by bonding wires 72 . The passive components 65 are mounted on and electrically coupled to the conductive traces 363 of the second wiring structure 36 .
[0097] FIG. 26 is a cross-sectional view of the semiconductor assembly 210 of FIG. 25 further provided with an encapsulant 85 . The encapsulant 85 covers the bonding wires 72 , the third device 61 , the passive components 65 and the second wiring structure 36 from above.
[0098] FIG. 27 is a cross-sectional view of the semiconductor assembly 210 of FIG. 26 further provided with solder balls 73 . The solder balls 73 are mounted on the conductive traces 343 of the first wiring structure 31 for external connection.
Embodiment 3
[0099] FIGS. 28-31 are schematic views showing a method of making a semiconductor assembly with vertical connecting elements on the wiring board in accordance with the third embodiment of the present invention.
[0100] For purposes of brevity, any description in Embodiments above is incorporated herein insofar as the same is applicable, and the same description need not be repeated.
[0101] FIG. 28 is a cross-sectional view of the structure with a stacked semiconductor sub-assembly 20 disposed in the cavity 316 of the wiring board 30 of FIG. 10 . The stacked semiconductor sub-assembly 20 is similar to that illustrated in FIG. 7 , except that it further includes a passive component 23 and a metal pillar 24 electrically coupled to the routing circuitry 21 and encapsulated in the molding compound 25 . The stacked semiconductor sub-assembly 20 is attached on the heat spreader 35 by a thermally and electrically conductive material 38 in contact with the heat spreader 35 , the first device 22 , the metal pillar 24 and the molding compound 25 .
[0102] FIG. 29 is a cross-sectional view of the structure with bonding wires 41 attached to the stacked semiconductor sub-assembly 20 and the wiring board 30 . The bonding wires 41 contact and are electrically coupled to the routing traces 212 of the routing circuitry 21 and the conductive traces 343 of the first wiring structure 31 .
[0103] FIG. 30 is a cross-sectional view of the structure with vertical connecting elements 58 on the wiring board 30 . The vertical connecting elements 58 are electrically connected to and contact the conductive traces 343 of the first wiring structure 31 . In this examples, the vertical connecting elements 58 are illustrated as solder balls 581 .
[0104] FIG. 31 is a cross-sectional view of the structure provided with an encapsulant 51 . The encapsulant 51 covers sidewalls of the vertical connecting elements 58 and the bonding wires 41 , the stacked semiconductor sub-assembly 20 and the wiring board 30 from above. Accordingly, a semiconductor assembly 310 is accomplished and includes a stacked semiconductor sub-assembly 20 , a wiring board 30 , bonding wires 41 , an encapsulant 51 and vertical connecting elements 58 . In this illustration, the stacked semiconductor sub-assembly 20 includes a routing circuitry 21 , a first device 22 , a passive component 23 , a metal pillar 24 , a molding compound 25 and a second device 27 , whereas the wiring board 30 includes a first wiring structure 31 , a heat spreader 35 and a second wiring structure 36 .
[0105] The first device 22 /passive component 23 and the second device 27 are disposed at two opposite sides of the routing circuitry 21 and face-to-face electrically connected to each other through the routing circuitry 21 therebetween. The metal pillar 24 is electrically connected to the routing circuitry 21 and extends through the molding compound 25 . The heat spreader 35 is electrically connected to the metal pillar 24 for ground connection and thermally conductible to the first device 22 for heat dissipation. The combination of the first wiring structure 31 and the second wiring structure 36 is electrically coupled to the routing circuitry 21 using the bonding wires 41 , and electrically coupled to the heat spreader 35 through metallized vias 364 . The vertical connecting elements 58 are mounted on and electrically coupled to the first wiring structure 31 and laterally surrounded by the encapsulant 51 .
[0106] FIG. 32 is a cross-sectional view of the semiconductor assembly 310 of FIG. 31 further provided with a third device 61 . The third device 61 is stacked over the encapsulant 51 , and electrically coupled to the vertical connecting elements 58 in the encapsulant 51 through solder balls 71 .
[0107] FIG. 33 is a cross-sectional view of the semiconductor assembly 310 of FIG. 32 further provided with solder balls 73 . The solder balls 73 are mounted on the conductive traces 363 of the second wiring structure 36 for external connection.
[0108] FIG. 34 is a cross-sectional view of another aspect of the semiconductor assembly according to the third embodiment of the present invention. The semiconductor assembly 320 is similar to that illustrated in FIG. 31 , except that the encapsulant 51 has a larger thickness than that of the solder balls 581 , and has openings 511 to expose the solder balls 581 from above.
[0109] FIG. 35 is a cross-sectional view of yet another aspect of the semiconductor assembly according to the third embodiment of the present invention. The semiconductor assembly 330 is similar to that illustrated in FIG. 31 , except that it includes metal posts 583 as the vertical connecting elements 58 .
Embodiment 4
[0110] FIGS. 36-37 are schematic views showing a method of making a semiconductor assembly with the second device wire bonded to the routing circuitry in accordance with the fourth embodiment of the present invention.
[0111] For purposes of brevity, any description in Embodiments above is incorporated herein insofar as the same is applicable, and the same description need not be repeated.
[0112] FIG. 36 is a cross-sectional view of a stacked semiconductor sub-assembly 20 . The stacked semiconductor sub-assembly 20 is similar to that illustrated in FIG. 7 , except that the second device 27 is electrically coupled to the routing traces 212 of the routing circuitry 21 using bonding wires 276 .
[0113] FIG. 37 is a cross-sectional view of a semiconductor assembly 410 with the stacked semiconductor sub-assembly 20 of FIG. 36 electrically coupled to the wiring board 30 of FIG. 10 through bonding wires 41 . The stacked semiconductor sub-assembly 20 is disposed in the cavity 316 of the wiring board 30 and attached to the heat spreader 35 using a thermally conductive material 39 . The bonding wires 41 contact and are electrically coupled to the routing traces 212 of the routing circuitry 21 and the conductive traces 343 of the first wiring structure 31 .
[0114] FIG. 38 is a cross-sectional view of the semiconductor assembly 410 of FIG. 37 further provided with an encapsulant 51 . The encapsulant 51 covers the bonding wires 41 and the stacked semiconductor sub-assembly 20 as well as selected portions of the wiring board 30 from above, and further fills up a gap 317 between the peripheral edges of the stacked semiconductor sub-assembly 20 and the interior sidewalls of the wiring board 30 .
[0115] FIG. 39 is a cross-sectional view of the semiconductor assembly 410 of FIG. 38 further provided with a third device 61 stacked over the stacked semiconductor sub-assembly 20 and the first wiring structure 31 of the wiring board 30 . The third device 61 is electrically coupled to the conductive traces 343 of the first wiring structure 31 through solder balls 71 .
[0116] FIG. 40 is a cross-sectional view of the inverted semiconductor assembly 410 of FIG. 38 further provided with third devices 61 and a heat spreader 81 at the second wiring structure 36 and solder balls 73 at the first wiring structure 31 . The third devices 61 are accommodated in a cavity 811 of the heat spreader 81 , and electrically coupled to the conductive traces 363 of the second wiring structure 36 by solder balls 71 . The heat spreader 81 is thermally conductive to the third devices 61 using a thermally conductive material 89 , and electrically coupled to the conductive traces 363 of the second wiring structure 36 by solder balls 75 . The solder balls 73 are mounted on the conductive traces 343 of the first wiring structure 31 for external connection.
Embodiment 5
[0117] FIG. 41 is a cross-sectional view of a semiconductor assembly in accordance with the fifth embodiment of the present invention.
[0118] The semiconductor assembly 510 is similar to that illustrated in FIG. 12 , except that (i) the stacked semiconductor sub-assembly 20 further includes a passive component 23 electrically coupled to the routing circuitry 21 and encapsulated in the molding compound 25 , and (ii) the first wiring structure 31 of the wiring board 30 has a larger thickness to create a deeper cavity 316 , and the routing circuitry 21 and the second device 27 of the stacked semiconductor sub-assembly 20 also extend into the cavity 316 of the wiring board 30 .
[0119] FIG. 42 is a cross-sectional view of the semiconductor assembly 510 of FIG. 41 further provided with a third device 61 at the first wiring structure 31 and solder balls 73 at the second wiring structure 36 . The third device 61 is stacked over the stacked semiconductor sub-assembly 20 and the wiring board 30 and electrically coupled to the first wiring structure 31 through solder balls 71 . The solder balls 73 are mounted on and electrically coupled to the second wiring structure 36 for external connection.
[0120] FIG. 43 is a cross-sectional view of the semiconductor assembly 510 of FIG. 41 further provided with a lens 88 at the first wiring structure 31 and solder balls 73 at the second wiring structure 36 . The lens 88 optically transparent to at least one range of light wavelengths is stacked over the stacked semiconductor sub-assembly 20 and mounted to the first wiring structure 31 using a joining material 881 . The solder balls 73 are mounted on and electrically coupled to the second wiring structure 36 for external connection. The exemplary material of the lens 88 includes, but is not limited to, polycrystalline ceramics (e.g. aluminum oxide ceramics, aluminum oxynitride, perovskytes, polycrystalline yttrium aluminum garnet, etc.), single crystalline ceramics, non-crystalline materials (e.g. inorganic glasses and polymers), and glass ceramics (e.g. silicate based). The joining material 881 may be metal-based material (such as solder), epoxy-based material, polyimide, any other resin or appropriate material.
Embodiment 6
[0121] FIG. 44 is a cross-sectional view of a semiconductor assembly in accordance with the sixth embodiment of the present invention.
[0122] The semiconductor assembly 610 is similar to that illustrated in FIG. 37 , except that (i) the stacked semiconductor sub-assembly 20 further includes a passive component 23 electrically coupled to the routing circuitry 21 and encapsulated in the molding compound 25 , and (ii) the first wiring structure 31 of the wiring board 30 has a larger thickness to create a deeper cavity 316 , and the routing circuitry 21 and the second device 27 of the stacked semiconductor sub-assembly 20 also extend into the cavity 316 of the wiring board 30 .
[0123] FIG. 45 is a cross-sectional view of the semiconductor assembly 610 of FIG. 44 further provided with a third device 61 at the first wiring structure 31 and solder balls 73 at the second wiring structure 36 . The third device 61 is stacked over the stacked semiconductor sub-assembly 20 and the wiring board 30 and electrically coupled to the first wiring structure 31 through solder balls 71 . The solder balls 73 are mounted on and electrically coupled to the second wiring structure 36 for external connection.
[0124] FIG. 46 is a cross-sectional view of the semiconductor assembly 610 of FIG. 44 further provided with a lens 88 at the first wiring structure 31 and solder balls 73 at the second wiring structure 36 . The lens 88 optically transparent to at least one range of light wavelengths is stacked over the stacked semiconductor sub-assembly 20 and mounted to the first wiring structure 31 . The solder balls 73 are mounted on and electrically coupled to the second wiring structure 36 for external connection.
[0125] The semiconductor assemblies described above are merely exemplary. Numerous other embodiments are contemplated. In addition, the embodiments described above can be mixed-and-matched with one another and with other embodiments depending on design and reliability considerations. For instance, the first wiring structure may have multiple through openings in an array and each stacked semiconductor sub-assembly is accommodated in its corresponding through opening. Also, the first wiring structure of the wiring board can include additional conductive traces to receive and route additional stacked semiconductor sub-assemblies.
[0126] As illustrated in the aforementioned embodiments, a distinctive semiconductor assembly is configured and includes a stacked semiconductor sub-assembly electrically coupled to a wiring board by bonding wires. Optionally, an encapsulant may be further provided to cover the bonding wires. For the convenience of below description, the direction in which the first surfaces of the routing circuitry and the first wiring structure face is defined as the first direction, and the direction in which the second surfaces of the routing circuitry and the first wiring structure faces is defined as the second direction.
[0127] The stacked semiconductor sub-assembly includes a first device, a second device, a routing circuitry and optionally a molding compound, and may be prepared by the steps of: electrically coupling the first device to the first surface of the routing circuitry detachably adhered over a sacrificial carrier by, for example, bumps; optionally providing the molding compound over the routing circuitry; removing the sacrificial carrier from the routing circuitry; and electrically coupling the second device to the second surface of the routing circuitry by, for example, bumps or bonding wires. As a result, the first and second devices, respectively disposed over the first and second surfaces of the routing circuitry, can be electrically connected to each other by the routing circuitry.
[0128] The first and second devices can be semiconductor chips, packaged devices, or passive components. The first device can be electrically coupled to the routing circuitry by a well-known flip chip bonding process with its active surface facing in the routing circuitry using bumps without metallized vias in contact with the first device. Likewise, after removal of the sacrificial carrier, the second device can be electrically coupled to the routing circuitry by a well-known flip chip bonding process with its active surface facing in the routing circuitry using bumps without metallized vias in contact with the second device. Alternatively, the second device is electrically coupled to the routing circuitry by wire bonding process with its active surface facing away the routing circuitry.
[0129] The routing circuitry can be a buildup circuitry without a core layer to provide primary fan-out routing/interconnection and the shortest interconnection distance between the first and second devices. Preferably, the routing circuitry is a multi-layered buildup circuitry and can include at least one dielectric layer and conductive traces that fill up via openings in the dielectric layer and extend laterally on the dielectric layer. The dielectric layer and the conductive traces are serially formed in an alternate fashion and can be in repetition when needed. Accordingly, the routing circuitry can be formed with electrical contacts at its first and second surfaces for first device connection from the first surface and second device connection and next-level connection from the second surface.
[0130] The wiring board includes a heat spreader, a first wiring structure and a second wiring structure. The first wiring structure includes electrical contacts at its second surface for the routing circuitry connection from the second direction, whereas the second wiring structure includes electrical contacts at its exterior surface for next-level connection from the first direction. The first wiring structure has a through opening extending from its first surface to its second surface to accommodate the heat spreader and the stacked semiconductor sub-assembly therein. The first wiring structure is not limited to a particular structure, and may be a multi-layered routing circuitry that laterally surround peripheral edges of the first device, the optional molding material and the heat spreader. For instance, the first wiring structure may include an interconnect substrate, a first buildup circuitry and a second buildup circuitry. The first and second buildup circuitries are disposed on both opposite sides of the interconnect substrate. The interconnect substrate can include a core layer, first and second routing layers respectively on both opposite sides of the core layer, and metallized through vias formed through the core layer to provide electrical connection between the first and second routing layers. Each of the first and second buildup circuitries typically includes a dielectric layer and one or more conductive traces. The dielectric layers of the first and second buildup circuitries are respectively deposited on opposite sides of the interconnect substrate. The conductive traces extend laterally on the dielectric layer and include conductive vias in contact with first and second routing layers of the interconnect substrate. Further, the first and second buildup circuitries can include additional dielectric layers, additional via openings, and additional conductive traces if needed for further signal routing. Accordingly, the outmost conductive traces at both the first and second surfaces of the first wiring structure can provide electrical contacts for the routing circuitry connection from its second surface and for the second wiring structure connection from its first surface. The second wiring structure is provided to cover the backside surface of the heat spreader and the first surface of the first wiring structure, and is electrically coupled to the heat spreader and the first wiring structure by metallized vias embedded in a dielectric layer of the second wiring structure and in contact with the backside surface of the heat spreader and the first surface of the first wiring structure. Accordingly, the heat spreader, covered by the dielectric layer of the second wiring structure from the first direction, can be mechanically supported by the second wiring structure and provide thermal dissipation and EMI shielding for the first device attached thereto using a thermally conductive material. As the heat spreader has a thickness less than that of the first wiring structure, a cavity is formed in the wiring board to accommodate the stacked semiconductor sub-assembly therein. Preferably, the heat spreader is a metal layer having peripheral edges adjacent to and attached to sidewalls of the through opening of the first wiring structure. Optionally, an additional metal layer may be further provided in contact with the heat spreader and the sidewalls of the through opening of the first wiring structure and completely cover a remaining portion of sidewalls of the through opening of the first wiring structure. The second wiring structure may be a multi-layered routing circuitry and laterally extends to peripheral edges of the first wiring structure. Preferably, the second wiring structure is a multi-layered buildup circuitry without a core layer, and includes dielectric layers and conductive traces in repetition and alternate fashion. The conductive traces include metallized vias in the dielectric layer and extend laterally on the dielectric layer. The outmost conductive traces of the first and second wiring structures can respectively accommodate conductive joints, such as solder balls or bonding wires, for electrical communication and mechanical attachment with an assembly, an electronic device, an additional heat spreader, an additional wiring board or others. For instance, a third device may be a semiconductor chip and mounted over and electrically coupled to the second wiring structure through a plurality of bonding wires, or be a ball grid array package or a bumped chip and mounted over and electrically coupled to the first wiring structure or the second wiring structure through a plurality of solder balls. As another aspect of the present invention, an additional heat spreader may be mounted over the second surface of the first wiring structure, and the second device can be disposed in a cavity of the additional heat spreader and thermally conductible to the additional heat spreader through a thermally conductive material. Further, the additional heat spreader may be electrically coupled to the first wiring structure for ground connection by, for example, solder balls in contact with the additional heat spreader and the outmost conductive traces of the first wiring structure. Alternatively, an additional wiring board may be stacked over the stacked semiconductor sub-assembly and the wiring board and electrically coupled to the first wiring structure from the second surface of the first wiring structure. More specifically, the additional wiring board can include a third wiring structure, a fourth wiring structure and an additional heat spreader. The third wiring structure has a through opening extending from its first surface to its second surface to accommodate the additional heat spreader and the second device therein. Preferably, the third wiring structure is a multi-layered routing circuitry and laterally surround peripheral edges of the additional heat spreader and a selected portion of the sub-assembly outside of the through opening. For instance, the third wiring structure may include an interconnect substrate having a core layer, routing layers respectively on both opposite sides of the core layer, and metallized through vias formed through the core layer to provide electrical connection between both the routing layers. Alternatively, the third wiring structure may be a multi-layered buildup circuitry without a core layer, and includes dielectric layers and conductive traces in repetition and alternate fashion. In any case, the third wiring structure can include electrical contacts at its opposite first and second surfaces for electrical connection with the first wiring structure and with the fourth wiring structure. Accordingly, the third wiring structure can be electrically coupled to the first wiring structure by, for example, solder balls, between the second surface of the first wiring structure and the first surface of the third wiring structure, whereas the fourth wiring structure can be electrically coupled to the second surface of the third wiring structure by metallized vias. Further, the fourth wiring structure is also electrically coupled to the heat spreader disposed in the through opening of the third wiring structure by metallized vias for ground connection. As a result, when the second device of the sub-assembly is disposed in the through opening of the third wiring structure, the heat spreader of the additional wiring board can provide thermal dissipation and EMI shielding for the second device attached thereto using a thermally conductive material. Preferably, the fourth wiring structure is a multi-layered routing circuitry and laterally extends to peripheral edges of the third wiring structure. For instance, the fourth wiring structure may be a multi-layered buildup circuitry without a core layer, and include dielectric layers and conductive trace in repetition and alternate fashion. As a result, the fourth wiring structure can include conductive traces at its exterior surface to provide electrical contacts from the second direction, and a third device may be optionally stacked over and electrically coupled to the exterior surface of the fourth wiring structure. Additionally, when the stacked semiconductor sub-assembly is an optical sub-assembly, a lens optically transparent to at least one range of light wavelengths may be stacked over the sub-assembly and mounted on the first wiring structure of the wiring board.
[0131] The bonding wires provide electrical connections between the routing circuitry of the sub-assembly and the first wiring structure of the wiring board. In a preferred embodiment, the bonding wires contact and are attached to the second surface of the routing circuitry exposed from the through opening of the first wiring structure and the second surface of the first wiring structure. As a result, the first and second devices can be electrically connected to the wiring board for external connection through the routing circuitry and the bonding wires.
[0132] Optionally, an array of vertical connecting elements may be further provided in electrical connection with the wiring board for next-level connection. Preferably, the vertical connecting elements contact and are electrically coupled to the first wiring structure from the second surface of the first wiring structure. The vertical connecting elements can include metal posts, solder balls or others, and may be laterally covered by an encapsulant. As the vertical connecting elements have a selected portion not covered by the encapsulant, a third device can be further provided to be electrically coupled to the vertical connecting elements.
[0133] The term “cover” refers to incomplete or complete coverage in a vertical and/or lateral direction. For instance, in a preferred embodiment, the heat spreader covers the first device in the first direction regardless of whether another element such as the thermally conductive material is between the first device and the heat spreader.
[0134] The phrases “attached to”, “attached on”, “mounted to” and “mounted on” includes contact and non-contact with a single or multiple element(s). For instance, in a preferred embodiment, the peripheral edges of the heat spreader are attached to the sidewalls of the through opening regardless of whether the peripheral edges of the heat spreader contact the sidewalls of the through opening or are separated from the sidewalls of the through opening by an adhesive.
[0135] The phrases “electrical connection”, “electrically connected” and “electrically coupled” refer to direct and indirect electrical connection. For instance, in a preferred embodiment, the bonding wires directly contact and are electrically connected to the first wiring structure, and the routing circuitry is spaced from and electrically connected to the first wiring structure by the bonding wires.
[0136] The “first direction” and “second direction” do not depend on the orientation of the semiconductor assembly, as will be readily apparent to those skilled in the art. For instance, the first surfaces of the routing circuitry and the first wiring structure face the first direction and the second surfaces of the routing circuitry and the first wiring structure face the second direction regardless of whether the semiconductor assembly is inverted. Thus, the first and second directions are opposite one another and orthogonal to the lateral directions. Furthermore, the first direction is the upward direction and the second direction is the downward direction when the outer surface of the second wiring structure faces in the upward direction, and the first direction is the downward direction and the second direction is the upward direction when the outer surface of the second wiring structure faces in the downward direction.
[0137] The semiconductor assembly according to the present invention has numerous advantages. For instance, the first and second devices are mounted on opposite sides of the routing circuitry, which can offer the shortest interconnect distance between the first and second devices. The routing circuitry provides primary fan-out routing/interconnection for the first and second devices, whereas the wiring board provides a second level fan-out routing/interconnection. As the routing circuitry of the sub-assembly are connected to the first wiring structure of the wiring board by bonding wires, not by direct build-up process, the simplified process steps result in lower manufacturing cost. The heat spreader can provide thermal dissipation, electromagnetic shielding and moisture barrier for the first device. The second wiring structure can provide mechanical support for the heat spreader and dissipate heat from the heat spreader. The semiconductor assembly made by this method is reliable, inexpensive and well-suited for high volume manufacture.
[0138] The manufacturing process is highly versatile and permits a wide variety of mature electrical and mechanical connection technologies to be used in a unique and improved manner. The manufacturing process can also be performed without expensive tooling. As a result, the manufacturing process significantly enhances throughput, yield, performance and cost effectiveness compared to conventional techniques.
[0139] The embodiments described herein are exemplary and may simplify or omit elements or steps well-known to those skilled in the art to prevent obscuring the present invention. Likewise, the drawings may omit duplicative or unnecessary elements and reference labels to improve clarity.
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A thermally enhanced semiconductor assembly with three dimensional integration includes a stacked semiconductor sub-assembly electrically coupled to a wiring board by bonding wires. A heat spreader that provides an enhanced thermal characteristic for the stacked semiconductor sub-assembly is disposed in a through opening of a wiring structure. Another wiring structure disposed on the heat spreader not only provides mechanical support, but also allows heat spreading and electrical grounding for the heat spreader by metallized vias. The bonding wires provide electrical connections between the sub-assembly and the wiring board for interconnecting devices assembled in the sub-assembly to terminal pads provided in the wiring board.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to oscillating drive axles for vehicles, industrial as industrail tractors or the like, and more particularly to the lubrication system for the trunnion bearing assemblies for pivotally mounting axles on these types of vehicles. One or more axles of the vehicles may be pivotally attached to the vehicle body so as to accommodate movement of the vehicle over rough terrain. These axles are commonly attached to the vehicle frame by means of a trunnion bearing assembly.
2. Description of the Prior Art
It is known to provide oscillating drive axle structures for large off-the-road wheeled vehicles so that all four drive wheels will stay in contact with the ground regardless of the unevenness of the terrain. It is also known to mount the entire axle structure, including the differential housing, on a pair of longitudinally spaced bearings carried by support members bolted to the frame and disposed in fore-and-aft alignment on the front and rear sides of the differential housing, with the axle structure therefore oscillating about the fore-and-aft axis of the bearings.
Lubrication for such bearings is important, however, since the bearings are located underneath the vehicle, they present a problem both in terms of access and in terms of safety for the maintenance men who may have to crawl under the vehicle to service said bearings. The prior art, which teaches lubrication via the usual grease fittings, is exemplified by U.S. Pat. No. 3,702,196, issued Nov. 7, 1972 to Krutis and, U.S. Pat. No. 3,811,699, issued May 21, 1974 to Casey.
Another method for lubricating the trunnion bearings is disclosed in U.S. Pat. No. 3,481,421, issued Dec. 2, 1969 to Sullivan, wherein the oscillating axle bearings are lubricated automatically by using the oil within the differential housing. While this prior art structure tends to perform quite satisfactorily, it is more complicated in construction and therefore more expensive to manufacture.
SUMMARY OF THE INVENTION
The axle trunnion lubrication system of this invention solves the previously-noted servicing problems by eliminating all crawling under the vehicle as well as all periodic maintenance in regard to the lubrication of these trunnion bearings. In addition, the lubrication system of this invention neither requires fluid communication with the interior of the differential housing nor does it utilize the lubricant contained within the differential housing.
The lubrication system of this invention makes use of cored or hollow trunnion support castings that are filled with lubricating fluid and thus, in addition to their trunnion support function, also act as lubricating fluid reservoirs. These lubricating fluid reservoirs, which extend both above and below the trunnion bearing bores are connected via fluid passage means with the trunnion bearings so as to permit the flow of lubricating fluid from the reservoirs to the trunnion bearings.
In addition, further fluid passage means are utilized to fluidly connect the trunnion bearings with thrust bearings and to permit the flow of lubricating fluid from the trunnion bearings to the thrust bearings. In addition, the thrust plate together with a thrust plate cover and the thrust bearings themselves define a cavity that is adapted to hold lubricating fluid.
Thus, according to the present invention, a novel arrangement of components is provided to permit the lubrication of both the trunnion and thrust bearings by utilizing the hollow trunnion supports as lubricating fluid reservoirs. This construction is both simple, foolproof, inexpensive and needs no moving parts. A further benefit of this construction is that these lubricant-filled trunnion supports provide lifetime lubricant reservoirs, with no service or periodic maintenance being required under normal operating conditions.
Other features and advantages of the invention will become more readily understood by persons skilled in the art when following the detailed description in conjunction with the several drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view, partially broken away, of a trunnion mounted axle that incorporates the lubrication system of this invention.
FIG. 2 is a simplified end view of the rear trunnion support incorporating an annular sleeve bearing and a wear sleeve associated therewith.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, particularly FIG. 1, there is illustrated a pivoting axle assembly shown generally at 10 which may, for example, be attached to the rear or tractor portion of a vehicle which also includes a front implement unit, such as a loader, with the tractor unit and implement unit being joined together by means of a vertical steering coupling so as to provide an articulated vehicle. An example of such an articulated vehicle is shown in U.S. Pat. No. 3,563,329 to Licari. As is well known in the art, the tractor unit includes an engine and transmission (not shown) that are operatively connected to power a pair of the rear wheels. A drive line and U-joint system transmit power from the transmission to the oscillating, pivoting or swing axle assembly 10 through an input member or pinion shaft 12.
Axle assembly 10, which is more or less conventional, includes a pair of oppositely extending axle housing portions 16, intermediate the inner ends of which is secured a differential housing or "banjo" structure portion 18. It will be understood that the "banjo" housing includes housing portion 18 and a cover (not shown), substantially enclosing a central lower portion of the assembly and forming a lubricant sump in the bottom thereof. Structure portion 18 is provided with laterally spaced surrounding portions 20 adjacent the inner ends of each axle housing 16, respectively, with anti-friction bearings 22 being carried by supporting portions 20.
A differential casing 24, preferably formed in two parts, is rotatably carried on spaced bearings 22 by opposed sleeve portions 26 and 28 formed on casing 24. Casing 24 is also provided with an annular flange to which is secured, for rotation therewith, a ring gear 30. Ring gear 30 and casing 24 are driven by a beveled pinion 32 which is keyed to input or pinion shaft 12 adjacent the innermost end thereof. Pinion shaft 12 is rotatably carried by a plurality of anti-friction bearings in a manner well known in the art.
The gear assembly (not shown) housed within differential casing 24 may be of any form of construction which is suitable for the transmission of power from pinion 32 to axle shafts 34 which extend coaxially of the axle housing portions 16, respectively.
Differential housing portion 18 of axle assembly 10 is transversely rockable on a front and rear trunnion arrangement shown generally at 36 and 38, respectively. As best seen in FIG. 1, front and rear trunnions 36 and 38 respectively are conveniently formed as integral and axially aligned front and rear portions 40 and 42 respectively, of differential housing 18. A front trunnion support 44 and a rear trunnion support 46 are disposed on either side of differential housing 18 and are secured to a pair of vehicle frame members (not shown) through a plurality of bolts (not shown) that pass through apertures 50.
Rear trunnion 38 is supported within rear trunnion support 46 by a sleeve bearing 52 of preferably cylindrical construction, attached to cylindrical through bore 54 of trunnion support 46. The inner surface of sleeve bearing 52, which is preferably provided with a continuous central groove 56, bears against the outer surface of a cylindrical wear sleeve 58 which surrounds and is physically attached to rear trunnion 38. The outer surface of wear sleeve 58 takes the form of a generally cylindrical bearing surface. The inner end of trunnion bore 54 is closed off by a retaining plate 60 which also serves to retain a seal 62.
Axial end thrust of axle assembly 10, relative to the vehicle, is taken up by a pair of opposed annular thrust washers 64 and 66 whose opposed inner surfaces can be contacted by the opposite sides of a thrust plate 68 bolted to the circular end face 70 of rear trunnion 38. Trunnion support 46 is provided with a peripheral recess or step 67 in its bore 54 to permit the insertion of the outer portion of plate 68. Inner thrust washer 64 is attached to rear trunnion 38 by a plurality of pins 72 whereas outer thrust washer 66 is held, by a plurality of pins 74, to the inner surface of a cover plate 76 bolted to rear trunnion support 46. An O-ring seal 78 prevents the discharge of lubricant between cover plate 76 and rear trunnion support 46.
Similar to the preceding description with reference to rear trunnion 38, front trunnion 36 is also provided with a wear sleeve 58 and sleeve bearing 52 is attached to the cylindrical bore 54 of front trunnion support 44. A pair of retaining plates 60 are removably secured on either side of front trunnion support 44 and are adapted to also contain a pair of seals 62 therein.
It should be understood at this time that front and rear trunnions 36 and 38 respectively are transversely rockable or pivotable via their wear sleeves 58 against sleeve bearings 52 in front and rear trunnion supports 44 and 46 respectively. These trunnion and bearing arrangements are of conventional construction, with the thrust function being taken care of by thrust plate 68 and opposed thrust washers 64 and 66.
Sleeve bearings 52 as well as thrust washers 64 and 66 are preferably of a metallic composition and therefore require lubrication. To this end, front and rear trunnion supports 44 and 46 take the forms of cored castings which in addition to their support function also serve as lubricant reservoirs 80. As best seen in FIG. 2, rear trunnion support 46, which is so substantially similar to front trunnion support 44, that the latter need not be described separately, has its end portions, containing apertures 50, closed off by means of expanding plugs 82. The trunnion support upper wall portion 84 is provided with a filler plug 86 and a vent plug 88, whereas curved bottom wall portion 90 is provided with drain plug 92. These top and bottom wall portions are joined by side wall portions 89 and 91. The generally-cylindrical center wall portion 94 is provided with preferably vertically-directed upper and lower apertures 95, 96 (FIG. 2) axially aligned with upper and lower apertures 97 and 98, respectively, in sleeve bearing peripheral central groove 56.
Each of the front and rear trunnion support reservoirs 80 is initially filled with lubricant, with conventional vent plug 88 permitting excess lubricant to escape in the case of lubricant expansion. The lubricant then enters sleeve bearing central groove 56 via central wall upper and lower apertures 95, 96, respectively, and groove apertures 97, 98, respectively, in order to perform its lubricating function. The escape of lubricant from front trunnion arrangement 38 is prevented by seals 62, whereas a small amount of lubricant can escape from the clearance between rear trunnion support bearing 52 and wear ring 58 in a rearward or outwardly direction to provide lubricant for thrust washers 64 and 66. In time, the cavity 69, formed between thrust plate 68, cover plate 76 and thrust washers 64 and 66, will completely fill with lubricant, with the escape therefrom being prevented by O-ring seal 78.
Under normal operating conditions, lubricant-filled trunnion supports 44 and 46 contain enough lubricant to provide lifetime lubrication for front and rear trunnions 36 and 38, respectively, with no service or periodic maintenance being required. This arrangement is simple, foolproof, inexpensive and has no moving parts. In contrast to the prior art structures, no periodic lubricant replenishment is necessary and no fluid communication is required with the interior of the differential housing.
It should be understood that the structural details and functional relationships of the sleeve bearings relative to the wear sleeves could of course be modified. For example, instead of having a groove in the sleeve bearing, the groove could readily be incorporated into wear ring. Furthermore, the apertures from reservoir 80 into the bearing-wear sleeve interface need not be vertically directed.
From the foregoing, it is believed that those familiar with the art will readily recognize and appreciate the novel concept and features of the present invention. Obviously, while the invention has been described in relation to only a limited number of embodiments, numerous variations, changes and substitutions of equivalents will present themselves to persons skilled in the art and may be made without necessarily departing from the scope and principles of this invention. As a result, the embodiment described herein is subject to various modifications, changes and the like, without departing from the scope and spirit of the invention with the scope thereof being determined solely by reference to the claims appended hereto.
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A vehicle having a swing axle, front and rear trunnion bearing assemblies for supporting this axle and front and rear trunnion supports wherein the trunnion supports each take the form of a cored or hollow casting that is filled with lubricating fluid and thus acts as a fluid reservoir. First passage means in fluid communication with the trunnion bearings permit the flow of lubricating fluid from the reservoir to the trunnion bearings, with second passage means providing fluid communication with the trunnion bearings and a pair of thrust bearings.
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BACKGROUND
[0001] The disclosed subject matter relates generally to instruments useful in the drilling of wells and, more particularly, to a directional drilling instrument that may be useful in guiding the direction of the borehole as it is being drilled.
[0002] When drilling vertical, horizontal, or extended reach wells, obtaining accurate measurements of inclination and azimuth is a fundamental requirement. Typically, the drilling equipment includes a directional drilling instrument located within the drill string near the drill bit. The directional drilling instrument is configured to collect data regarding its orientation, and communicate that data to the surface where it may be analyzed to determine its current position, such that the position of the drill bit may be derived. Collecting and analyzing this data over a period of time allows the operator of the drilling process to accurately guide the drill bit to a desired location that will enhance production from the resulting well.
[0003] Typically, as is shown in FIG. 1 , a conventional directional drilling instrument 10 is comprised of a plurality of sensors 12 , 13 14 , such as accelerometers and/or magnetometers (e.g., typically three of each), that are positioned orthogonally to one another to form a 3-axis sensor capable of collecting data in a 3-dimensional system (e.g., X, Y, and Z coordinates) that may be used to locate and guide drilling. The magnetometers and accelerometers are oriented, relative to each other, so that their like axes are coincidentally aligned—X accelerometer parallel to X magnetometer, Y accelerometer parallel to Y magnetometer and Z accelerometer parallel to Z accelerometer. This alignment simplifies the mathematics involved in solving for the axes specific outputs, with respect to the orientation of the directional drilling instrument. The sensor 12 is oriented with its sensitive axis perpendicular to the instrument Z axis such that movement of the directional drilling instrument 10 along the Z axis will produce an output signal corresponding to the magnitude of such a movement. As will be appreciated by those skilled in the art, movement of the sensor 12 along the X and Y axes will result in a near-zero or non-significant output signal. The sensor 13 is oriented with its sensitive axis perpendicular to the X axis such that movement of the directional drilling instrument 10 along the X axis will produce an output signal corresponding to the magnitude of such a movement. And finally, the sensor 14 is oriented with its sensitive axis perpendicular to the Y axis such that movement of the directional drilling instrument 10 along the Y axis will produce an output corresponding to the magnitude of such a movement.
[0004] Historically, oil well drilling trajectories were originally most often vertical wells. However, over time the trajectories have varied to low angle slant wells (build and hold), to directional “S” shaped wells (Directional Drilling, with gradual changes in both inclination and direction) then to Extended Reach (3D designer well paths) and then to the current standard, “Long Lateral” horizontal wells. Currently, the typical development drilling well profile consists of a vertical segment drilled deep enough to get close to the production depth, a curved section with a borehole angle build up rate (and direction) calculated for the best fit between the hole size and the completion tubular program as well as the specified reservoir target(s) and the production volume. The horizontal section is designed for enhanced resource recovery. The horizontal section of these wells may commonly be almost as long, or longer, than the vertical section. Wells of this type only produce at desired capacities if they are actually located accurately in the target reservoir. Accordingly, wellbore position uncertainty is critical to well productivity.
[0005] The orthogonal orientation of the sensors in a conventional directional drilling instrument 10 is problematic in these types of wells. For example, the orthogonal orientation of the sensors 12 , 13 , 14 causes the output of one or more of the sensors to be either almost zero or full scale when the directional drilling instrument is oriented so that the direction of drilling substantially aligns with one of the X, Y, or Z-axis, such as would occur in the vertical or horizontal portions of the well. For example, when the directional sensor 10 is oriented vertically with the gravitational vector generally aligned with the Z-axis, the X and Y-axis sensors 13 , 14 will typically experience little variation, and thus, be at or near zero output, whereas the Z-axis sensor 12 will undergo substantial variation and may be at or near maximum output. Similarly, when directional sensor 10 is oriented horizontally with the gravitational vector, as shown in FIG. 1B , for example, generally aligned with the Y-axis, the Z and X-axis sensors 12 , 13 will typically experience little variation, and thus, be at or near zero output, whereas the Y-axis sensor 14 will undergo substantial variation and may be at or near maximum output.
[0006] Turning now to FIG. 1C , a stylistic representation of the sensor 12 is shown in a position where the directional drilling instrument is in a substantially vertical orientation. In this orientation, gravity is acting in a direction that substantially aligns with the sensitive axis of the sensor 12 . Similarly, as is shown in FIG. 1D , with the directional drilling instrument 10 in a substantially vertical orientation, the sensor 13 , on the other hand, has its sensitive axis at a right angle to the gravity vector. Thus, movement of the drilling instrument in a substantially vertical direction can produce very high output signals from the sensor 12 and very low output signals from the sensor 13 . Those skilled in the art will appreciate that the sensor 14 will have similar characteristics to the sensor 13 with respect to near vertical drilling.
[0007] Both conditions (zero and full scale) are sub-optimum for the sensors in use in directional drilling instruments, and the corresponding accuracy of the resulting calculations suffers a significant degradation. Of course, this degradation in the calculations will undesirably affect the ability of the operator to guide the drilling process and locate the well at its desired location.
[0008] Moreover, those skilled in the art will appreciate that the sensors 12 , 13 , 14 are more prone to physical damage when the sensitive axis is perpendicular to the direction that a force is applied to the sensor. For example, when drilling a vertical section of the well such that the sensitive axis and gravity vector of the sensor 12 are aligned, a substantial jarring or shock in the vertical direction can result in damage to and ultimate failure of the sensor 12 , whereas the sensors 13 , 14 are less likely to be damaged.
BRIEF SUMMARY
[0009] The following presents a simplified summary of the disclosed subject matter in order to provide a basic understanding of some aspects of the disclosed subject matter. This summary is not an exhaustive overview of the disclosed subject matter. It is not intended to identify key or critical elements of the disclosed subject matter or to delineate the scope of the disclosed subject matter. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.
[0010] One aspect of the disclosed subject matter is seen in a directional drilling instrument that comprises a chassis, a first sensor and a second sensor. The chassis has a longitudinal axis, and the first sensor is coupled to the chassis and oriented at a first angle (w 1 ) relative to the longitudinal axis of the chassis. The second sensor is coupled to the chassis and oriented at a second angle (w 2 ) relative to the longitudinal axis of the chassis. The first and second angles are non-identical and non-orthogonal relative to the longitudinal axis.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0011] The disclosed subject matter will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:
[0012] FIG. 1A is a stylistic representation of one embodiment of a conventional directional drilling instrument deployed in a vertical section of a well bore;
[0013] FIG. 1B is a stylistic representation of one embodiment of a conventional directional drilling instrument deployed in a horizontal section of a well bore;
[0014] FIG. 1C is a stylistic representation of one embodiment of a conventional single axis accelerometer that may be employed in the directional drilling instrument of FIG. 1A as a Z-axis sensor;
[0015] FIG. 1D is a stylistic representation of one embodiment of a conventional single axis accelerometer that may be employed in the directional drilling instrument of FIG. 1A as an X-axis sensor;
[0016] FIGS. 2A-2D are stylistic representations of an embodiment of a desired orientation of sensors within a directional drilling instrument;
[0017] FIG. 3A is a side view of one embodiment of a chassis of a directional drilling instrument configured to receive a plurality of sensors;
[0018] FIG. 3B is a side view of one embodiment of a sensor in an orientation where its sensitive axis is skewed from the gravity vector;
[0019] FIG. 4A is a stylistic representation of the directional drilling instrument of FIGS. 1 and 2 disposed in a vertical segment of a well;
[0020] FIG. 4B is a stylistic representation of the directional drilling instrument of FIGS. 1 and 2 disposed in a horizontal segment of a well; and
[0021] FIGS. 5A and 5B stylistically illustrate the angular measurements W and T that may be used to define the orientation of the sensors set forth in FIGS. 2A-2D and other alternatives.
[0022] While the disclosed subject matter is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the disclosed subject matter to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosed subject matter as defined by the appended claims.
DETAILED DESCRIPTION
[0023] One or more specific embodiments of the disclosed subject matter will be described below. It is specifically intended that the disclosed subject matter not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made to achieve the developers' specific goals, such as compliance with system-related and business related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but may nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. Nothing in this application is considered critical or essential to the disclosed subject matter unless explicitly indicated as being “critical” or “essential.”
[0024] The disclosed subject matter will now be described with reference to the attached figures. Various structures, systems and devices are schematically depicted in the drawings for purposes of explanation only and so as to not obscure the disclosed subject matter with details that are well known to those skilled in the art. Nevertheless, the attached drawings are included to describe and explain illustrative examples of the disclosed subject matter. The words and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. No special definition of a term or phrase, i.e., a definition that is different from the ordinary and customary meaning as understood by those skilled in the art, is intended to be implied by consistent usage of the term or phrase herein. To the extent that a term or phrase is intended to have a special meaning, i.e., a meaning other than that understood by skilled artisans, such a special definition will be expressly set forth in the specification in a definitional manner that directly and unequivocally provides the special definition for the term or phrase.
[0025] As will be discussed in more detail throughout, a directional drilling instrument is described that utilizes one or more of the principals associated with sensor axis orientation to provide for a directional drilling instrument (or any like navigational platform) that reduces individual sensor output degradation arising from the orientation of the instrument body. The principals described herein can be applied to a variety of sensors that may be utilized in directional drilling instruments, including accelerometers and magnetometers. The principals described herein allow the use higher order mathematical algorithms to detect and correct for misalignments in either the directional drilling sensor itself, a corresponding bottomhole assembly, or both. Moreover, the principals described herein may also be used to facilitate the detection and compensation for other environmental conditions, including, but not limited to, drillstring magnetism, adjacent cased hole well bores (magnetic interference), well bore geometric stability, drilling fluids (type and condition), thermal effects and individual sensor failure/s.
[0026] In one embodiment, the sensors within the directional drilling instrument may include a cluster of two, three or four accelerometers and two, three or four magnetometers where one or more of the sensor axes may be skewed relative to a conventional right-handed array. Additionally, one or more of the axes may be skewed relative to each other. This orientation creates a condition where each of the sensors delivers an output signal that falls near the middle of its capable range of output signals. Such a situation is highly desirable in that it enhances the accuracy of the measurement made by each individual sensor, and thus, the accuracy of the directional drilling instrument as a whole.
[0027] Those skilled in the art will appreciate that the principals set forth herein may be utilized to produce a directional drilling instrument that may provide accurate results in situations where only two sensors are employed. Such a two-sensor embodiment may be implemented to provide a lower cost design, or alternatively to allow a three or four-sensor instrument to continue to operate and provide acceptable results in the event that one or more of its sensors are damaged.
[0028] Referring now to the drawings wherein like reference numbers correspond to similar components throughout the several views and, specifically, referring to FIGS. 2A-2D , the disclosed subject matter shall be described in the context of a four-sensor directional drilling instrument that includes four sensors 202 - 205 . In one embodiment, the sensors 202 - 205 take the form of accelerometers manufactured by Honeywell as part number QAT-185 or magnetometers manufactured by Microtesla as part number 220368-PL-01, or both. Those skilled in the art, however, will appreciate that other specific sensors may be utilized without departing from the spirit and scope of the instant invention.
[0029] FIG. 2A illustrates a conventional right-hand coordinate system oriented with its Z-axis 210 generally corresponding to the longitudinal axis of the directional drilling instrument. The X and Y-axes 211 , 212 are positioned at 90° relative to the Z-axis and to each other. In conventional directional drilling systems, sensors are generally aligned with these axes. However, in the illustrated embodiment of the directional drilling instrument it may be seen that a first sensor 202 is positioned on a new axis A, which is located by rotating the original X-axis 211 through an angle of about −60° (clockwise in the XY plane) to form an axis X′ and then elevated by an angle of about 30°. As is shown in FIG. 2B , a second sensor 203 is positioned on a new axis B, which is located by rotating the original X-axis 212 through an angle of about −30° (clockwise in the XY plane) to form an axis X′ and then depressed by an angle of about 30°. As is show in FIG. 2C , a third sensor 204 is positioned on a new axis C, which is located by rotating the original X-axis through an angle of about 165° to form an axis X′ and then elevated by an angle of about 60°. As can be seen in FIG. 2D , a fourth sensor 205 is positioned on a new D axis, which is located by rotating the original X-axis through an angle of about −150° (clockwise in the XY plane) to form an axis K and then depressed by an angle of about −45°. Thus, the newly formed coordinate system A, B, C and D has the following relationships:
A to B=−145°; B to C=−150°; C to D=135°; and D to A=150°
[0034] Turning now to FIG. 3A , one embodiment of a chassis 400 is shown in which 4 sensors 402 - 405 , such as accelerometers and/or magnetometers may be located according to the angular relationships set forth with respect to FIGS. 2A-2D . Generally, the chassis 400 has a longitudinal axis 410 that aligns with a Z-axis 415 of a conventional 3-dimension coordinate system, which also includes an X-axis 420 and a Y-axis 425 as references for describing the orientation of the sensors 402 - 405 .
[0035] The first sensor 402 is located in a pocket 430 formed in the chassis 400 , wherein the pocket 402 includes a longitudinal axis 435 that is skewed from the 3-dimension coordinate system 415 , 420 , 425 according to the relationships described above. Further, the second, third and fourth sensors 403 - 405 are similarly positioned in pockets 431 - 433 with each of these pockets having longitudinal axes 436 - 438 , respectively. The axes 436 - 438 are also skewed from the 3-dimension coordinate system 415 , 420 , 425 according to the relationships described above. Those skilled in the art will appreciate that the chassis 400 may be formed from any suitably rigid material, including plastics, metals, etc., and the pockets 430 - 433 may be formed by casting or forming the chassis 400 with the pockets 430 - 433 formed therein. Alternatively, the chassis 400 could be initially formed without pockets and the pockets 430 - 433 could be subsequently formed therein via a machining or similar process. The size and construction of the pockets 430 - 433 may be sufficient to securely retain the sensors 401 - 404 in a desired orientation while limiting movement between the sensors 401 - 404 and the chassis 400 . It is envisioned that any of a variety of conventional retention systems may be employed. For example, in one embodiment it may be useful to retain the sensors 401 - 404 using a conventional snap ring arrangement; however, other methods, including, various mechanical and chemical processes may be employed, including, but not limited to, gluing, soldering, welding, screws, bolts, nuts, etc.
[0036] As can be seen in the stylistic drawing of FIG. 3B , the sensor 402 , for example, when constructed according to the principals set forth herein has its sensitive axis 480 skewed from the gravity vector 482 when the instrument 400 is vertically oriented. This orientation causes the sensor 402 to detect gravity, when oriented vertically at only a portion of its full-scale capability.
[0037] Turning now to FIG. 4A , a stylized representation of an instrument 500 having four accelerometers 501 - 504 arranged according to the principals set forth herein is shown, and these accelerometers 501 - 504 have the following angular relationships to the longitudinal axis of the instrument 500 : 45°, 60°, 60°, and 30°, respectively. The mathematical formula for calculating the output of the accelerometer 504 is as follows:
[0000] Output=sin(Angle of sensor+Angle of Instrument relative to the Gravity vector)×Gravity
[0000] Output=sin(30°+0°)×Gravity
[0000] Output=0.5 G.
[0038] Thus, when the instrument is arranged vertically, the output of the accelerometer 504 is advantageously at about its mid-range. Those skilled in the art will appreciate that similar mathematical relationships exist between accelerometers 501 - 503 , based on the degree to which each accelerometer is skewed from the gravity vector such that each of their output signals is a fraction of full scale.
[0039] Turning now to FIG. 4B , when the instrument 500 is oriented horizontally, such as in the horizontal portion of a wellbore, the angle of the instrument relative to the gravity vector is about 90°, and thus, the mathematical calculations for determining the output of the accelerometer 504 in the horizontal orientation is as follows:
[0000] Output=sin(Angle of sensor+Angle of Instrument relative to the Gravity vector)×Gravity
[0000] Output=sin(30°+90°)×Gravity
[0000] Output=0.866 G.
[0040] Thus, the output of the accelerometer 504 , whether it is vertically or horizontally oriented, is advantageously at a fraction of full scale. Those skilled in the art will appreciate that similar mathematical relationships exist between accelerometers 501 - 503 , based on the degree to which each is skewed from the gravity vector such that each of their output signals is a fraction of full scale in both horizontal and vertical orientations.
[0041] Those skilled in the art, having the benefit of the instant description, will appreciate that the precise angular orientation of each of the accelerometers/magnetometers relative to the longitudinal axis of the instrument may vary substantially without departing from the spirit and scope of the instant invention. For example, it is anticipated that varying the angular orientation of each of the sensors by as much as 5° from their designed orientation in any plane will nevertheless produce results having acceptable accuracy for at least some applications.
[0042] Those skilled in the art will also appreciate that the sensors may be oriented in a variety of positions and still result in acceptable accuracy. For example, three embodiments that describe orientations that may be useful are set forth in Tables I-III below. In these tables, a simpler convention is adopted to define the orientation of the individual sensors, as opposed to the convention used to describe the embodiment set forth in FIGS. 2A-2D . In the embodiments set forth below, the orientation of the sensors A, B, C, and D are defined by two angular components, W and T. W, as shown in FIG. 5A , represents the angle of the longitudinal axis of the individual sensor relative to the longitudinal axis of the tool, and thus, would theoretically fall in the range of 0°-180°. T, as shown in FIG. 5B , represents the angle of the longitudinal axis of the sensor as viewed from the top of the tool, and thus, would theoretically fall in the range of 0°-360°.
[0000]
TABLE I
Sensor
W
T
A
23°
180°
B
85°
337°
C
102°
94°
D
68°
43°
[0000]
TABLE II
Sensor
W
T
A
20°
210°
B
90°
330°
C
90°
90°
D
70°
30°
[0043] Table III, set forth below, represents the angles W and T for the embodiment set forth in FIGS. 2A-2D .
[0000]
TABLE III
Sensor
W
T
A
120°
60°
B
30°
330°
C
150°
195°
D
45°
150°
[0044] The particular embodiments disclosed above are illustrative only, as the disclosed subject matter may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the disclosed subject matter. Accordingly, the protection sought herein is as set forth in the claims below.
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One aspect of the disclosed subject matter is seen in a directional drilling instrument that comprises a chassis, a first sensor and a second sensor. The chassis has a longitudinal axis, and the first sensor is coupled to the chassis and oriented at a first angle (w1) relative to the longitudinal axis of the chassis. The second sensor is coupled to the chassis and oriented at a second angle (w2) relative to the longitudinal axis of the chassis. The first and second angles are non-identical and non-orthogonal relative to the longitudinal axis.
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FIELD
The present application relates to the removal of nutrients, such as phosphorous and nitrates from water and/or wastewater.
BACKGROUND
In 2008, the Water Resources Institute in Washington D.C., identified excess nutrients in water as one of the leading causes of water degradation, and reported over 415 areas worldwide experiencing the devastating economic and environmental effects of eutrophication (algal bloom) and hypoxia (oxygen dissolved depletion). Recent surveys in United States and Europe found that a staggering 78 percent of the assessed continental U.S. coastal area and approximately 65 percent of Europe's Atlantic coast exhibit symptoms of eutrophication. Furthermore, trends in agricultural practices, energy use, and population growth indicate that coastal eutrophication will be an ever growing problem.
To combat hypoxia it is essential to reduce nutrients from land-based wastewater reaching rivers in runoff. This is effectively achieved by an adequate treatment of sewage and by reducing agricultural fertilizers reaching surface waters. It is estimated that 25% of all water body impairments are due to the effects associated with the excess of nutrients in water (oxygen depletion, algal growth, biological extinction). To palliate these effects municipalities have begun looking beyond conventional treatment technologies and have lowered effluent discharge limits for nitrogen and phosphorous compounds. These advanced technologies involve new bioreactors and/or biological processes.
About one-third of the influent phosphorous in wastewater treatment plants (WWTP) is removed by both the settling of the insoluble fraction, and by cellular growth which occurs in both primary and secondary treatments. Typical heterotrophic bacteria present in secondary treatment use phosphorous for cellular growth to make up 2.5% of their weight. The complete removal of nutrients occurs after the secondary treatment. That is, after the elimination of carbon and ammonia pollutants. These processes are followed by both denitrification to eliminate the nitrates, and by phosphorous removal. Currently, phosphorous removal is primarily done by the addition of coagulants and flocculants. Because these chemicals create much sludge and are expensive, biological phosphorous removal is becoming the preferred option. In view of the foregoing, it would be desirable to develop a more efficient and cost effective method for nutrient removal.
SUMMARY
In accordance with particular process, method and system aspects there is provided a biological manner of treating water/wastewater. Treatment is undertaken in bioreactor configured to treat the water/wastewater through a first process of denitrification followed by a second process of biological phosphorus removal. The bioreactor may be defined by multiple stages arranged in compact vertical alignment, for example, to reduce a footprint of the bioreactor and to feed the water/wastewater between the stages using gravity. The stages may comprise, in order, a Deaeration stage, an Anoxic stage, an Anaerobic stage, and an Aerobic stage. Continuous vacuum operation in the Deaeration stage enhances the physical removal of oxygen and other dissolved gases, which can interfere with nutrient removal in later stages.
Thus, in one aspect there is provided a method of removing nutrient from water/wastewater. The method comprises denitrifying the water/wastewater through a first process; and, subsequently, biologically removing phosphorus through a second process. The first process and second process are undertaken in a bioreactor comprising multiple stages in compact vertical alignment whereby water/wastewater is fed into the top of the Deaeration stage and flows downward sequentially from one stage to the other.
The method may comprise removing dissolved oxygen and other gases in the water/wastewater in a Deaeration stage; applying denitrifying organisms in an Anoxic stage to reduce nitrates in the water/wastewater to free nitrogen; applying phosphorous accumulating organisms (PAOs) in an Anaerobic stage to uptake acetates and convert them to polyhydroxyalkanoates (PHAs) and release orthophosphate into water/wastewater and applying oxygen in an Aerobic stage to the PAOs to remove the orthophosphates. The multiple stages are defined by the Deaeration stage, Anoxic stage, Anaerobic stage and Aerobic stage.
Removing dissolved oxygen and other gases may comprise applying a continuous vacuum in the Deaeration stage to enhance the physical removal of oxygen and other dissolved gases that interfere with the removal of nutrients from the water/wastewater in subsequent of the multiple stages. The method may comprise removing dissolved oxygen and other gases by a physical deaeration process to control the anoxic and anaerobic conditions in the Anoxic and Anaerobic stages without addition or recycle of a sludge.
The Anoxic stage may operate in an anoxic condition to reduce a nitrate level of the water/wastewater to no more than about 0.5 mg/L. The nitrate level of the water/wastewater is reduced in the Anoxic stage so as to avoid interfering with a biological phosphorus removal process of the Anaerobic stage and Aerobic stage. The method may comprise adding a carbon source to said water/wastewater in said Anoxic stage to facilitate nitrate removal by the denitrifying organisms.
Denitrifying organisms within the Anoxic stage may be contained in the stage using a high interfacial area packing.
The method may comprise feeding water/wastewater to the top of the Deaeration stage. From the Deaeration stage water/wastewater is pumped to the Anoxic stage from which water/wastewater flows down to the Anaerobic stage and next to the Aerobic stage by gravity thereby to reduce pumping requirements compared to conventional horizontal biological nutrient removal plants.
The multiple stages may be defined by a modular bioreactor using a cylindrical cross section for each of the stages to enhance control and mixing of flows relative to a rectangular cross section. The method may comprise at least one of expanding, substituting and modifying at least one of the multiple stages by adding a modular cylindrical section.
In another aspect there is provided a bioreactor for treating water/wastewater to remove nutrients. The bioreactor comprises multiple stages configured to treat the water/wastewater through a first denitrification process followed by a second biological phosphorus removal process without interference between the first and second processes. The multiple stages are further configured to be in vertical alignment whereby water/wastewater is fed at the top of the Deaeration stage and water/wastewater exits from the bottom stage of the bioreactor called Aerobic stage.
The multiple stages comprise a Deaeration stage in which dissolved oxygen and other gases in the water/wastewater are removed; an Anoxic stage in which nitrates in the water/wastewater are reduced to free nitrogen by denitrifying organisms and the free nitrogen is removed (for example, escapes through a vent in the Anoxic stage); an Anaerobic stage in which phosphorous accumulating organisms (PAOs) uptake acetates and convert them to polyhydroxyalkanoates (PHAs) and release orthophosphate into water/wastewater; and an Aerobic stage in which the PAOs remove the orthophosphates from the water/wastewater.
The bioreactor may be configured utilizing a compact vertical configuration of the multiple stages to reduce a footprint of the bioreactor compared to conventional horizontal biological nutrient removal plants.
In another aspect, there is provided A water/wastewater treatment process comprising: providing water/wastewater to a bioreactor to produce a treated effluent, the bioreactor comprising multiple stages configured to treat the water/wastewater through a first denitrification process followed by a second biological phosphorus removal process, the multiple stages further configured to be in vertical alignment whereby water/wastewater is fed into the top of the Deaeration stage and flows downward sequentially from one stage to the other. The bioreactor may be configured utilizing a compact vertical configuration of the multiple stages to reduce a footprint of the bioreactor compared to conventional horizontal biological nutrient removal plants. Treatment of the water/wastewater through the first and second processes may be performed without interference between the first and second processes thereby to increase removal efficiency relative to conventional simultaneous removal processes.
The process may comprise feeding the water/wastewater into the top of the Deaeration stage and flows downward sequentially from one stage to the other. thereby to reduce pumping requirements compared to conventional horizontal biological nutrient removal plants. The multiple stages may comprise, in order: a Deaeration stage in which dissolved oxygen and other gases in the water/wastewater are removed; an Anoxic stage in which nitrates in the water/wastewater are reduced to free nitrogen by denitrifying organisms and the free nitrogen is removed (for example, escapes through a vent in the Anoxic stage); an Anaerobic stage in which phosphorous accumulating organisms (PAO) uptake acetates and convert them to polyhydroxyalkanoates (PHAs) and release orthophosphate into water/wastewater.
These and other aspects will become apparent in the detailed description that follows by reference to the following figures.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a schematic drawing of the bioreactor and the method in accordance with an embodiment;
FIG. 2 graphically illustrates the semi-qualitative concentration profiles of the BOD 5 , COD, dissolved oxygen (DO), NO 3 − , and total phosphorous (TP) in water using the method of FIG. 1 ;
FIG. 3 graphically illustrates the removal profile of dissolved oxygen using the method of FIG. 1 ;
FIG. 4 graphically illustrates the inlet and outlet nitrate concentrations to highlight nitrate removal efficiency of the bioreactor using the method of FIG. 1 ;
FIG. 5 graphically illustrates the inlet and outlet phosphorus concentration using the method of FIG. 1 ; and
FIG. 6 illustrates a Compact Upright Bioreactor for the Elimination of Nutrients, showing its configuration and geometry in accordance with an embodiment.
DETAILED DESCRIPTION
A method of removing nutrient from water/wastewater is provided. With reference to FIG. 1 , the method comprises treating the water in the four treatment stages, where the four stages are arranged in a vertical alignment with respect to each other. The four stages comprise: a Deaeration stage 2 in which dissolved gases, such as oxygen and nitrogen, in the water are removed; an Anoxic stage 3 in which denitrifying bacteria reduce nitrates to free nitrogen, and the free nitrogen escapes from the water; an Anaerobic stage 5 in which phosphorous accumulating organisms (PAOs) uptake acetates and convert them polyhydroxyalkanoates (PHAs); and an Aerobic stage 6 in which the PAOs uptake phosphates in the water and convert them to polyphosphates and store them internally.
As used herein, the term “wastewater” refers to wastewater comprising a high concentration of both phosphorus and nitrates, for example, a concentration of phosphorus which is at least about 5 mg/L and generally higher, e.g. at least about 8 mg/L, and a nitrate concentration that is at least about 20 mg/L and generally higher, e.g. at least about 25 mg/L, which has a total suspended solid content of about 10 mg/L. An example of wastewater in accordance with an embodiment for treatment, thus, includes wastewater that has undergone primary and secondary wastewater treatments.
To treat water/wastewater ( 1 ) in accordance with an embodiment, a first step of the treatment is the deaeration or vacuum stage. In this stage of the treatment, dissolved oxygen and nitrogen are physically removed from the wastewater by deaeration. Deaeration may be accomplished by the application of a vacuum, for example, using any standard source of vacuum. Vacuum deaeration is applied continuously at a pressure below atmospheric to achieve a level of about 0.01-0.1 mg/L dissolved oxygen. In one embodiment, vacuum at an absolute pressure in the range of about 50-63 cm of Hg at a temperature in the range of about 20-25° C. is applied. To enhance removal of dissolved oxygen, liquid distributers such as a misting nozzle ( 2 - a ), and packing ( 2 - b ), e.g. polypropylene packing such as Tri-Packs®, may also be used in the deaeration stage to improve liquid distribution and to increase surface area for removal of dissolved oxygen as described by Alvarez-Cuenca, M. Ph.D. Thesis (1979). (The University of Western Ontario, Canada, the contents of which are incorporated herein by reference). The deaerated water/wastewater is collected in the reservoir section of the Deaeration stage ( 2 - c ) (referring to FIG. 1 ).
The effluent from the Deaeration or vacuum stage enters the Anoxic stage. In the Anoxic stage, the operating conditions favor the breakdown of nitrates (i.e. denitrification) by denitrifying organisms such as Pseudomonas, Aerobacter, Achromobacter and Micrococcu . Such denitrifying organisms are inherent in the wastewater. In order to support the growth of the denitrifying organisms, a source of carbon ( 4 ) is required. Suitable sources of carbon for this purpose include biodegradable organic matter such as methanol or volatile fatty acids (VFA) (e.g. electron donors). The amount of carbon source required is an amount suitable to support organism growth so as to achieve denitrification to a desired level, e.g. to achieve denitrification to a nitrate level of no more than about 0.5 mg/L. Although the wastewater may itself include carbon suitable for use by the denitrifying organisms, generally an external source of carbon is required on an ongoing basis during the treatment to result in an adequate level of carbon in the Anoxic stage, e.g. a total amount of carbon of about 250-300 mg/L. This Anoxic stage is conducted under anoxic conditions at a temperature suitable to encourage denitrification, e.g. preferably less than about 40° C., more preferably in the range of about 15-30° C., e.g. in the range of about 20-25° C. The pH may range from about 6.5-9.0, and preferably in the range of about 7.0 to 8.5. Denitrification in the Anoxic stage occurs until a low level of nitrate is achieved, e.g. preferably, until a level of denitrification of at least about 95%, e.g. in the range of about 95-100% denitrification to result in a nitrate level on the wastewater of, for example, no more than about 0.5 mg/L. An enhanced rate of denitrification may be achieved in the Anoxic stage compared to conventional denitrification units because of the very low oxygen dissolved in the effluent of the previous stage (Deaeration stage). By the effective removal of oxygen, the chemical equilibrium in the denitrification reaction is displaced towards the breakdown of nitrates. The low oxygen concentration in the anoxic stage is intended to lower the consumption of carbon source used, thus making the process more economic than in conventional denitrification processes.
To facilitate the denitrification process in the Anoxic stage, packing is used to maintain the large inventory of denitrifiers in this stage and achieve high nitrate removal. At the same time, the bio film formation of denitrifiers on the surface of the packing reduces their flow to the Anaerobic stage thus avoiding the interference of the denitrifiers in the phosphorus removal process. Any suitable packing may be used, including for example, a packing comprising Hydroxyl-Pac media.
The denitrified effluent from the Anoxic stage flows to the Anaerobic stage in which anaerobic conditions is maintained. During this stage, the conditions favor the growth of phosphorus-accumulating organisms such as Acinetobacter, Candidatus Accumulibacter phosphatis and Pseudomonas putida GM6, which are also inherent in the wastewater. These organisms uptake and convert the remaining carbon source (e.g. volatile fatty acids) into poly-b-hydroxyalkanoates with the energy provided from the breakdown of intracellular poly-phosphates. As a result of this breakdown, the phosphorus-accumulating organisms release ortho-phosphate into the wastewater. In order to facilitate the activity of phosphorus-accumulating organisms, sludge separated by the ceramic membrane may be recycled back to the Anaerobic stage. This reduces the need for fresh sludge addition and increases efficiency.
In the final stage, in accordance with an embodiment of the present method, the Aerobic stage, the conditions favour phosphorus utilization by phosphorus-accumulating organisms. The effluent from the Anaerobic stage is exposed to aerobic conditions, e.g. dissolved oxygen in the range of about 2.5-3.5 mg/L. Oxygen may be added to the liquid using known methods, for example, bubbled into the liquid using an air diffuser. Preferably the pH during this stage is in the range of about 7-8 and the temperature is in the range of about 18-25° C. During the Aerobic stage, the phosphorus-accumulating organisms oxidize poly-b-hydroxyalkanoates, and using the energy released from this oxidation to uptake ortho-phosphates from the water/wastewater and to convert them into poly-phosphates which can be used by the organisms to reconstruct their cell structure, as well as for growth and reproduction. Thus, oxidation results in the uptake of the phosphorus in the wastewater by the organisms. The aerobic stage of the method is conducted until a suitable reduction of phosphorus level is achieved, for example, a level of no more than about 0.5 mg/L of phosphorus, and preferably a level of less than about 0.1 mg/L of phosphorus.
The treated water may be filtered ( 7 ) to collect and recycle PAOs back into the Anaerobic stage using well-established technology like membranes. Persons of ordinary skill in the art will appreciate that some elements of the bioreactor of FIG. 1 such as various holding tanks, air or liquid streams, liquid flow meters, air flow meters, pressure gauges, vacuum gauges, pumps (e.g. gear pump, vacuum pump, and metering pump) pressure air filters, globe, air or sampling valves and air diffuser are shown but not described. Further description is provided with reference to FIG. 6 .
In another aspect, a bioreactor is provided that is sufficient to treat wastewater in accordance with a method as detailed above. Referring to FIG. 6 , a bioreactor 10 according to one embodiment is provided. The bioreactor 10 comprises a cylindrical column suitable to conduct each stage of the treatment method in vertical alignment including, from top to bottom, a Deaeration stage 20 , an Anoxic stage 30 , an Anaerobic stage 40 and an Aerobic stage 50 . The cylindrical stages may be made of materials that are suitable for the biological treatment of wastewater, such as fiberglass, steel or concrete. The use of cylindrical stages provide better mixing and also permits more readily stage replacement, e.g. for upsizing and capacity expansion. The capacity of each stage will vary depending on the process that occurs here within. Adjacent stages are separated by flat flanges (e.g. 29 ) and connected by outer pipes including an influent pipe 12 connecting the influent holding tank 14 to the Deaeration stage, pipe 22 connecting Deaeration stage to Anoxic stage, pipe 32 connecting Anoxic stage to Anaerobic stage, pipe 42 connecting Anaerobic stage to Aerobic stage and effluent pipe 52 connecting the Aerobic stage to an effluent holding tank 54 .
The Deaeration stage 20 comprises three sections, an upper section 20 a , a mid-section 20 b and a lower section 20 c , each of which are vertically aligned and in communication. The top portion 20 a of Deaeration stage 20 is connected to a vacuum pump 24 suitable to generate a vacuum appropriate to remove dissolved oxygen from water, e.g. vacuum in the range of about 50-63 cm of Hg. The water is delivered to the Deaeration stage by a liquid distributor 21 such as a misting nozzle. Mid-section 20 b comprises a packing suitable to provide liquid distribution as well as more surface area for DO removal, e.g. plastic hollow spherical packing called Tri-Packs®. The lower section 20 c receives water from the mid-section 20 b . Water is pumped from the Deaeration stage 20 to the Anoxic stage 30 using a gear pump 26 which is connected to the pipe 22 as well as a liquid flow meter 28 .
The Anoxic stage 30 also comprises high interfacial area packing as described suitable to maintain the denitrifying microorganisms within the stage. A tank 34 holding carbon sources is connected via pipes 35 a and 45 a to each of the Anoxic and Anaerobic stages 30 , 40 . In addition, a sludge-containing tank 37 is connected via pipe 38 to the Anoxic stage 30 and Anaerobic stage 40 . Tank 37 is present for the purposes of the inoculation of the lab scale treatment of synthetic wastewater which is lacking in denitrifying bacteria and phosphorus-accumulating organisms. The sludge tank provides sludge to the Anoxic and Anaerobic stages to seed the bioreactor with the required microorganisms. Such seeding is not required in the industrial scale treatment of secondary effluent wastewater which already comprises these organisms.
The Aerobic stage 50 includes a globe valve 53 a to permit removal of sludge from the tank, when necessary.
Each of the Anoxic, Anaerobic and Aerobic stages includes vents 31 to vent gases formed therein and prevent pressure build-up.
The effluent holding tank 54 is connected to a microfiltration membrane unit 60 via metering pump 56 a and pipe 62 a . The final filtered effluent 64 from the membrane unit 60 may enter into a disinfection unit (not shown) via piping 64 for further treatment while retentate comprising PAOs, is fed back to the Anaerobic stage 40 using metering pump 56 b through pipe 62 b.
In use, water/wastewater (influent) to be treated is fed into the bioreactor 10 . The water/wastewater, which may initially be held in a holding tank, is fed into the Deaeration stage in which dissolved oxygen and other gases are physically removed by vacuum. A water distributor may be used to create small water droplets to ease the removal of dissolved oxygen by vacuum. Flow of the water over packing also increases water distribution and thereby increases deaeration efficiency. The flowrate of the water is adjusted to permit sufficient deaeration of the water/wastewater, e.g. to a level of less than about 0.2-0.5 mg/L dissolved oxygen. A reservoir 20 c is designed to hold the liquid to about 6 hours, and often less than 6 hours. The deaerated water then flows into the Anoxic stage 30 in which denitrifying microorganisms are established and function to breakdown or remove nitrates from the water. A suitable carbon source 34 is fed into the Anoxic stage from a carbon mixture tank to support the growth of the denitrifying microorganisms. Residence time in the Anoxic stage to achieve a desirable level of denitrification, e.g. a level of no more than about 0.5 mg/L nitrates, is generally in the range of about 2-4 hours. The denitrified water then flows into the Anaerobic stage 40 where the anaerobic condition and addition of carbon source 34 favor the activity of phosphorus-accumulating organisms (PAOs). Residence time in the Anaerobic and Aerobic stages is sufficient to reduce phosphorus to a level of no more than about 0.1 mg/L. To achieve this reduction in phosphorus level in the wastewater, residence time in the Anaerobic stage is generally about 0.5-2 hours, while residence time in the Aerobic stage 50 is generally about 4-12 hours. The treated water (effluent 52 ) may then be fed through a membrane filtration system (generally 60) to separate the PAOs from water and yield the final effluent 64 with phosphorus concentration of 0.1 mg/L or less.
The use of a vacuum stage allows the fast physical removal of oxygen and other unwanted gases that can interfere with the biological removal of the nutrients in the next stages. For example, the effective removal of oxygen shifts the chemical equilibrium in the denitrification reaction towards the breakdown of nitrates in the Anoxic stage. This prevents potential interference of nitrates with the biological elimination of phosphorus in the Anaerobic and Aerobic stages thereby resulting in higher removal efficiency of both relative to conventional biological nutrient removal technologies.
In addition, the upright modular design of the bioreactor provides flexibility with respect to installation, substitution and/or expansion, and due to its vertical arrangement, provides a smaller footprint. In addition, gravity flow of the liquid due to the vertical orientation of the bioreactor results in fewer pumps and power consumption costs relative to the horizontal flow between stages in currently existing biological nutrient removal reactors
The use of a method and bioreactor as set out above is exemplified in the following example which is not to be construed as limiting.
EXAMPLE
A synthetic wastewater solution comprising the components shown in Table 1 below was prepared.
TABLE 1
Concentration
Chemical Compounds
(volume or grams)
COD
Nitrate
P
CH 3 COOH
5-10
ml
Variable
—
—
Butyric Acid
5-10
ml
Variable
—
—
Propanoic Acid
5-10
ml
Variable
—
—
Methanol
10
ml
Variable
—
—
NaOH (Salt)
15 grams in 2 L
KNO 3
4.109
g
—
25 mg/L
—
KH 2 PO 4
5.535
g
—
—
10 mg/L (P)
Na 2 HPO 4 •H 2 O
5.614
g
—
—
10 mg/L (P)
Na 2 HPO 4
5.776
g
—
—
10 mg/L (P)
Minerals
NaHCO 3
34.7
g
—
—
—
KCl
4.5
g
—
—
—
CaCl 2 •H 2 O
1.512
g
—
—
—
MgSO 4 •7H 2 O
1.512
—
—
—
FeCl 3
1.5
g/L
—
—
—
Na 2 SO 4
0.1
g/L
—
—
—
ZnCl 2 (Zinc chloride)
0.12
g/L
—
—
—
The solution was fed into the Deaeration stage of the bioreactor from the top as shown in FIG. 6 . Vacuum was applied to this stage at an absolute pressure of between about 50-63 cm of Hg. The temperature was maintained between about 20-25° C. The dissolved oxygen concentration was measured to be 0 mg/L by a sensor.
The performance of the bioreactor was monitored by comparing influent specifications to target effluent specifications. Predicted effluent specifications throughout the course of the treatment, determined based on optimal conditions, are graphically illustrated in FIG. 2 for comparison with actual specifications.
TABLE 2
Design Influent
Design Effluent
Parameters
Specifications
Specifications
Flowrate (L/day)
120
120
BOD 5 (mg/L)
50
<5
COD (mg/L)
80
<10
TSS (mg/L)
0-8
<5
NO 3 (mg/L)
25
<0.5
P (mg/L)
8
<0.1
DO (mg/L)
4-6
2.5-3.5
The dissolved oxygen (DO) concentration at each stage of the treatment for a six month period are set out in Table 3 below and graphically illustrated in FIG. 3 . As can be seen, the DO values at each stage approach the target or objective value over time.
TABLE 3
The inlet and outlet nitrate concentration at each stage in the bioreactor over a period of time is shown in FIG. 4 . FIG. 4 also compares the nitrate removal performance with the target nitrate profile. The experimental nitrate removal results correspond closely with the target profile. The inlet nitrate concentration was variable ranging from 21 mg/L to 34 mg/L and the outlet nitrate concentrations reached 0.1 mg/L as the commissioning of the bioreactor progressed and steady state was achieved. This graph shows superior and consistent nitrate removal performance of the bioreactor.
Phosphorus removal efficiency of the bioreactor over a period of time was also monitored as shown in FIG. 5 . Inlet phosphorus concentration was varied from 10 mg/L up to 30 mg/L. The reason for varying the inlet phosphorus concentration was to analyze its effect on the phosphorus removal efficiency as increased phosphorus concentration in the influent is believed to enrich the PAO population in the bioreactor and consequently enhance the process. Initially, during the commissioning period, there was a considerable difference between the inlet and outlet phosphorus concentrations. During the first month of the unit operation, the overall phosphorus removal efficiency of the bioreactor reached as high as 60%. However, the phosphorus removal efficiency was reduced to approximately 12% during the commissioning period. These results are consistent with those observed in BNR plants during the commissioning period. Once continuous operating conditions are well established and a sufficient PAO population is attained phosphorus removal efficiency will increase to approach the target phosphorus concentration in the effluent of <0.1 mg/L. Due to the slow growth rate of PAOs and their hypersensitivity to the operating parameters of the bioreactor, high phosphorus removal efficiency will be attained 6 months after a large population of PAOs is established.
Microscopic analysis and well known technique called Fluorescent in Situ Hybridization (FISH) clearly identified the presence of PAOs, more specifically Candidatus Accumulibacter Phosphatis in both Anaerobic and Aerobic stages. These techniques must be used regularly to monitor and optimize the biological phosphorus removal process.
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In accordance with particular process, method and system aspects there is provided a biological manner of treating water/wastewater. Treatment is undertaken in bioreactor configured to treat the water/wastewater through a first process of denitrification followed by a second process of biological phosphorus removal. The bioreactor may be defined by multiple stages arranged in compact vertical alignment, for example, to reduce a footprint of the bioreactor and to feed the water/wastewater between the stages using gravity. The stages may comprise, in order, a Deaeration stage, an Anoxic stage, an Anaerobic stage, and an Aerobic stage. Continuous vacuum operation in the Deaeration stage enhances the physical removal of oxygen and other dissolved gases.
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RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Application Ser. No. 60/872,189, filed on 1 Dec. 2006, and which is incorporated herein by reference.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
[0002] This invention was made with Government support under Contract No. DE-AC0996-SR18500 awarded by the United States Department of Energy. The Government has certain rights in the invention.
FIELD OF THE INVENTION
[0003] This invention is directed towards a container for receiving contaminated clothing for use at Step Off Pad areas. In many industrial environments, such as a radiation area, workers must exit at a Step Off Pad (SOP) to remove any protective clothing and place it into a clothing container. Any contaminated waste other than clothing should also be directed into a separate waste container.
BACKGROUND OF THE INVENTION
[0004] Contaminated clothing containers for use at SOPs are commercial trash containers upon which a laundry bag or waste bag is placed for the receipt of clothing or other waste. The prior art containers do not lend themselves to providing any assistance to workers who need to remove contaminated clothing. The conventional handles and lids on such containers are also not well suited for the unique demands of a SOP within a radiologically contaminated area.
[0005] Accordingly, there remains room for improvement and variation within the art.
SUMMARY OF THE INVENTION
[0006] It is one aspect of at least one of the present embodiments to provide a sturdy and stable container for holding removed protective clothing that helps workers maintain their balance while changing out of protective clothing.
[0007] It is a further aspect of at least one embodiment of the present invention to provide a protective clothing receptacle which is portable, weather proof, and easy to decontaminate.
[0008] It is a further aspect of at least one embodiment of the present invention to provide for a receptacle for receiving used protective clothing which can be easily transported by a single user, can be used to steady a worker while changing clothes, has a lid with a stop mechanism to facilitate easy closure, has dimensions that are compatible with standard size commercial laundry bags and has sufficient dimensions and capacity such that a single operator can easily and safely move the wheeled container when fully loaded with contaminated clothing.
[0009] These and other aspects of the invention are provided by a container for receiving contaminated clothing comprising: a compartment defining an interior volume; a lid adapted for engaging the compartment, the lid capable of being operatively disposed between a closed position and an open position relative to the compartment; a frame, supported by the compartment and extending around an exterior of the compartment, the frame having at least one rear portion positioned a spaced distance from a rear of the lid and the compartment; at least one hinge connecting at least one rear portion of the frame to the lid; a handle attached to the lid, the handle extending outwardly from the lid at least about 30 cm from an edge of the lid; a pair of wheels positioned along a rear of the compartment; and wherein the lid, when in an open position, will engage a portion of a rear wall of the compartment, thereby preventing the lid from further movement in a rear direction; and, wherein the at least one hinge further defines a stop member for limiting movement of the lid beyond about a 90° angle relative to the compartment and the at least one rear portion of the frame extends above the horizontal plane of the lid when the lid is in a closed position.
[0010] Further, the handle is a telescopic handle and is attached to an upper surface of the lid or to a front portion of the lid and the compartment nests within a cavity defined by an undersurface of the lid and the frame defines a rear portion which extends a spaced distance from a rear of the lid and a rear wall of the compartment.
[0011] These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] A fully enabling disclosure of the present invention, including the best mode thereof to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying drawings.
[0013] FIG. 1 is a perspective view of one exemplary embodiment of the present invention.
[0014] FIG. 2 is a perspective view similar to FIG. 1 and showing additional details in partial section.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] Reference will now be made in detail to the embodiments of the invention, one or more examples of which are set forth below. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents. Other objects, features, and aspects of the present invention are disclosed in the following detailed description. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary constructions.
[0016] In describing the various figures herein, the same reference numbers are used throughout to describe the same material, apparatus, or process pathway. To avoid redundancy, detailed descriptions of much of the apparatus once described in relation to a figure is not repeated in the descriptions of subsequent figures, although such apparatus or process is labeled with the same reference numbers.
[0017] Conventional containers used for receiving used radiological protective clothing make use of modified commercial trash containers. Such trash containers provide no support mechanism to assist workers in the removal of protective clothing. In addition, the free swinging lids on such commercial embodiments can frequently unbalance an empty or near empty container. Likewise, closing a free swinging lid can be difficult when there is no counter balancing load within the interior of the commercial trash container.
[0018] As best seen in reference to FIGS. 1 and 2 , the container 10 comprises a compartment 12 having an upper lid 14 , lid 14 having slightly greater dimensions than compartment 12 . A lower surface of lid 14 defines a flange 16 which projects downwardly and extends around a perimeter of lid 14 . In this manner, the upper rim of compartment 12 nests within flange 16 and lid 14 . Attached to compartment 12 is a frame 20 having a front portion 26 and a rear portion 24 each of which extend slightly above the container 10 and lid 14 when lid 14 is in a closed configuration as seen in FIG. 1 . Lid 14 is attached by a pair of hinges 22 to the portion of rear frame 24 . Preferably hinges 22 are connected to flange 16 along opposite sides of lid 14 . Frame 20 can be attached to the compartment 12 via any conventional mounting hardware suitable for the respective materials. Such attachments may include the use of threaded fasteners 28 or welding of the frame 20 to the compartment 12 .
[0019] Lid 14 and compartment 12 may be provided from stainless steel. The use of stainless steel provides for a sturdy construction that may be easily cleaned and decontaminated while maintaining a weight that still permits easy portability of the container. On a lower rear of compartment 12 , there are a pair of wheels provided which are connected by an axle 42 which, as illustrated, extends along an exterior of compartment 12 . A pair of mounting brackets 44 are used to attach and support the axle 42 and wheel 40 to the compartment 12 .
[0020] An upper surface of lid 14 supports thereon a handle 30 which comprises a handle tube 34 , an extension 36 , a terminal end of extension 36 defining a grip 32 . The interplay between extension 36 and handle tube 34 is such that member 36 may telescope in and out of the interior of the handle tube 34 . The telescopic nature of the handle 30 allows for the telescopic end of extension 36 to extend outwardly along the side of the container. When so extended, the handle provides a gripping surface 32 that an individual can grasp and use to steady, himself while removing contaminated clothing. Preferably, handle 30 , handle tube 34 , and extension 36 are made of an inert metal, such as stainless steel.
[0021] As seen in reference to FIG. 2 , lid 14 may be pivoted freely to at least a 90° angle to provide for access to the interior 13 of compartment 12 . Preferably, hinges 22 may be attached to the flange 16 of lid 14 in which the attachment site of lid 14 provides a detent, stop member, or other blocking mechanism that will retain lid 14 in the illustrated open, upright configuration. As further seen in reference to FIG. 2 , by providing a limited amount of spacing between the lid and the rear wall of the compartment 12 , the engagement between the rear container wall and bottom rear edge of the raised lid can also limit the range of motion the lid can travel. As seen in FIGS. 1 and 2 , the rear edge of lid 14 extends beyond the rear compartment wall to facilitate the interengagement of the rear container wall and the bottom rear edge of lid 14 . Alternatively, lid 14 may rest against a portion of rear frame 24 which may also serve as a stop member to prevent the lid from free swinging on the container. Providing some type of stop member or other blocking mechanism with respect to the lid prevents the container from becoming unbalanced by a free swinging lid and also allows the handle 30 to be engaged while the lid is in an open configuration. As such, workers removing contaminated clothing can be supported by grasping handle 30 as well as front frame 26 and rear frame 24 .
[0022] While the overall size, shape, and dimensions of the container 10 and compartment 12 are not critical, it is advantageous to conform the dimensions to accommodate standard size commercial laundry bags. Such laundry bags can be attached to or suspended within the interior volume 13 of compartment 12 by any conventional means including clips, hooks, or other hardware (not illustrated). As seen in FIG. 2 , when lid 14 is in an upright, open position, there is sufficient clearance between the lid and the upper rim of compartment 12 such that placement of a laundry bag or liner along the rim of compartment 12 may be accomplished. While a rectangular container 10 is illustrated, other shapes, including round containers may be used.
[0023] The container 10 may be fabricated from a number of different materials. A stainless steel container, for instance, may be constructed having a weight of about 15 to 20 kilograms which provides stability when workers are using the various handles and bars to assist when removing protective clothing. While stainless steel is extremely durable and can be easily decontaminated, it is also recognized that other materials including fiberglass, plastic, other metals, or similar materials may be used to construct a waste container for protective clothing according to the details and disclosures set forth herein. One advantage of stainless steel or other metal is that the weight of the container is sufficient to resist being blown over by wind gusts for applications where the SOP may be outdoors.
[0024] While protective clothing removal occurs at contaminated radiation areas, the container also has advantages at other work sites where contaminated clothing must be removed and processed. For instance, surgical suites in hospitals, chemical processing facilities, food processing facilities, industrial waste collection, industrial cleaning, and bulk chemical transfer and handling operations are all representative environments where protective clothing is typically worn and must be collected from workers as they exit the work site. Many employers in industrial fields of technology provide protective uniforms, coveralls, and other protective outer wear for which the company is responsible for cleaning and maintaining. Providing the clothing receptacle as set forth herein at convenient locations for workers facilitates the collection of clothing and does so in a manner that allows the workers to safely remove the clothing and do so in a more expedient and efficient manner.
[0025] An additional advantage of a stainless steel or other heavy duty construction material is that a clean/decontaminated container can be used to transport protective clothing to a work area. For instance, a metal bracket suspended across the opening of compartment 12 can be used to hang protective gear. Subsequently, at the end of a shift, the same container can be used to receive the contaminated clothing.
[0026] The present invention can also be used in the hotel/motel industry as a safer alternative to conventional laundry carts. The waste container is easily transported and can be used to collect and transport soiled bedding, used towels, and other items that require laundering. Safety guidelines for the safe handling of used linens and towels dictate that workers need to protect themselves from such items using protective gear. The present invention allows for the materials to be received in the container and easily transported without exposure to other workers, hotel guests, etc. The present invention is also conducive to a laundry receptacle for the entertainment industry at locations such as pools and health clubs. Such facilities frequently provide towels for use by their patrons and guests which are returned to designated receptacles. The present invention provides a receptacle that is easy to use, holds a generous supply of soiled items, and may be transported to an onsite location if desired without additional worker or patron exposure to the soiled items.
[0027] Although preferred embodiments of the invention have been described using specific terms, devices, and methods, such description is for illustrative purposes only. The words used are words of description rather than of limitation. It is to be understood that changes and variations may be made by those of ordinary skill in the art without departing from the spirit or the scope of the present invention.
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A container ( 10 ) for receiving contaminated clothing from an industrial environment such as a radiation work area is provided. The container ( 10 ) provides for a telescopic handle ( 30 ) and a spaced frame ( 20 ) extending around the container ( 10 ) which workers can grasp to maintain balance while changing into and out of protective clothing. The container ( 10 ) is preferably made of a metal which provides sufficient stability and rigidity for workers to brace themselves. The container ( 10 ) has a fittable lid ( 14 ) which provides for a telescopic handle ( 30 ) which can be used to pivot the lid ( 14 ) as well as providing a handheld support for workers.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 60/491,569, filed Jul. 31, 2003.
[0002] This application is a continuation-in-part of co-pending U.S. patent application Ser. No. 10/744,683, filed Dec. 23, 2003. U.S. patent application Ser. No. 10/744,683 is a continuation of U.S. patent application Ser. No. 10/161,310, filed Jun. 3, 2002. U.S. patent application Ser. No. 10/161,310 has issued as U.S. Pat. No. 6,672,383. U.S. patent application Ser. No. 10/161,310 is a divisional of U.S. patent application Ser. No. 09/777,090, filed on Feb. 5, 2001. U.S. patent application Ser. No. 09/777,090 has issued as U.S. Pat. No. 6,405,795. U.S. patent application Ser. No. 09/777,090 is a divisional of U.S. patent application Ser. No. 08/981,070, filed Dec. 10, 1997. U.S. patent application Ser. No. 08/981,070 has issued as U.S. Pat. No. 6,209,632. U.S. patent application Ser. No. 08/981,070 was the National Stage of International Application No. PCT/CA96/00407, filed Jun. 11, 1996. International Application No. PCT/CA96/00407 claims benefit of Canadian Patent Application Serial No. 2,151,525, filed on Jun. 12, 1995.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] This invention generally relates to borehole telemetry. More particularly, the invention relates to an electrically insulating gap sub assembly used for electromagnetic telemetry between surface and subsurface locations or between multiple subsurface locations.
[0005] 2. Description of the Related Art
[0006] During a typical drilling operation, a wellbore is formed by rotating a drill bit attached at an end of a drill string. To provide for a more efficient drilling operation, various techniques may be employed to evaluate subsurface formations, such as telemetry, as the wellbore is formed. Generally, telemetry is a system for converting the measurements recorded by a wireline or measurements-while-drilling (MWD) tool into a suitable form for transmission to the surface. In the case of wireline logging, the measurements are converted into electronic pulses or analog signals that are sent up the cable. In the case of MWD, they are usually converted into an amplitude or frequency-modulated pattern of mud pulses. Some MWD tools use wirelines run inside the drill pipe. Others use wireless telemetry in which signals are sent as electromagnetic waves through the Earth. Wireless telemetry is also used downhole to send signals from one part of a MWD tool to another. The most commonly used drilling telemetry methods can be arranged into several distinct groups such as wireline, mud pulse, or electromagnetic (EM).
[0007] In the first telemetry group, wireline communication involves one or more insulated cables that has a wide bandwidth and thus can communicate large amounts of data quickly, but the cable must be pulled out of the hole when adding additional sections of drill pipe. This is time consuming and reduces overall drilling efficiency. It also may not be possible to rotate the drill string with the wireline cable in the hole.
[0008] In the second telemetry group, mud pulse telemetry, the drilling fluid is utilized as the transmission medium. As the drilling fluid is circulated in the wellbore, the flow of the drilling fluid is repeatedly interrupted to generate a varying pressure wave in the drilling fluid as a function of the downhole measured data. A drawback of the mud pulse technique is that the data transmission rates are very slow. Transmission rates are limited by poor pulse resolution as pressure pulses attenuate along the borehole and by the velocity of sound within the drilling mud. Further, while mud pulse systems work well with incompressible drilling fluids such as a water-based or an oil-based mud, mud pulse systems do not work well with gasified fluids or gases typically used in underbalanced drilling.
[0009] In the third telemetry group, electromagnetic (EM) telemetry, relatively low frequency (4-12 Hz) electromagnetic waves are transmitted through the earth to the surface where the signal is amplified, filtered, and decoded. Communication may also be accomplished in the reverse direction.
[0010] In a typical EM operation, generating and receiving the electromagnetic waves downhole involves creating an electrical break between an upper section and a lower section of a drill string to form a large antenna. Thereafter, sections of this antenna are energized with opposite electrical polarity often using a modulated carrier wave that contains digital information. The resulting EM wave travels through the earth to the surface where a potential difference may be measured between a rig structure and a point on the surface of the earth at a predetermined distance away from the rig.
[0011] Typically, the electrical break in the drill string is accomplished by a device referred to as a gap sub assembly. Generally, the gap sub assembly must electrically insulate the upper and lower sections of the drill string and yet be structurally capable of carrying high torsional, tensile, compressive, and bending loads. The known gap sub assembly includes an external non-conductive section with composite coatings to isolate the upper and lower sections. However, these coatings generally lack sufficient abrasion resistance when in contact with the abrasive rock cuttings and require frequent maintenance or replacement. In addition, the composite coatings typically do not provide a significant beneficial effect to the bending or compressive strength of the design. Additionally, the known gap sub assembly is expensive to manufacture. Furthermore, the known gap sub assembly is bulky and cumbersome to employ during a drilling operation.
[0012] Therefore, a need exists for a gap sub assembly that is capable of withstanding the abrasive environment of a wellbore. Further, there is a need for a gap sub assembly that is capable of withstanding the bending and compressive loading that occurs during a drilling operation. Furthermore, there is a need for a gap sub assembly that is cost effective to manufacture. Further yet, a need exists for a gap sub assembly that is compact and may be easily employed during a drilling operation.
SUMMARY OF THE INVENTION
[0013] This invention overcomes the problem of creating an electrical break in the drill string in a compact and cost effective yet highly robust method.
[0014] In one embodiment, an apparatus for use with an EM telemetry system is provided, comprising: a housing; a mandrel; a dielectric material disposed between the housing and the mandrel; and a first non-conductive gap ring disposed between the housing and the mandrel.
[0015] Optionally, the mandrel is bonded to the housing with the dielectric material. The housing and the mandrel may be configured to remain axially coupled in the event of failure of the dielectric material. The housing and the mandrel section may be attached by a threaded connection so that the housing and the mandrel remain axially coupled in the event of failure of the dielectric material. The dielectric material may be disposed in the threaded connection. The apparatus may further comprise an anti-rotation member configured so that the housing and the mandrel remain rotationally coupled in the event of failure of the dielectric material. The anti-rotation member may comprise at least one non-conductive torque pin disposed between the housing and the mandrel. The first gap ring may be fabricated from a toughened ceramic material. The first gap ring may provide structural support in bending and compression. The first gap ring is may be preloaded in compression between the housing and the mandrel to provide a seal between the housing and the mandrel. The dielectric material may be epoxy.
[0016] Further, the mandrel may comprise a first section and a second section coupled by a threaded connection. The housing may comprise a first section and a second section coupled by a threaded connection. The first gap ring may be disposed between the second section of the housing and the second section of the mandrel. The apparatus may further comprise a second non-conductive gap ring disposed between the first section of the housing and the first section of the mandrel. The apparatus may further comprise a first seal assembly disposed between the second section of the housing and the first section of the mandrel. The first seal assembly may comprise a first sleeve made from a relatively high strength, high temperature plastic; and at least one elastomer sealing element disposed between the first sleeve and the second section of the housing and at least one elastomer sealing element disposed between the first sleeve and the first section of the mandrel. The apparatus may further comprise a second seal assembly similar to that of the first seal assembly. The apparatus may further comprise: a first compression ring disposed between the first gap ring and the mandrel and a second compression ring disposed between the first gap ring and the housing. The compression rings may be made from a relatively soft, strain-hardenable material.
[0017] In another embodiment, an apparatus for use with an EM telemetry system is provided, comprising: a housing; a mandrel; a dielectric material bonding the mandrel to the housing, wherein the apparatus is configured so that the housing and the mandrel remain coupled in the event of failure of the dielectric material.
[0018] In another embodiment, an apparatus for use with an EM telemetry system, comprising: a housing; a mandrel; means for electrically isolating the housing from the mandrel and for primarily coupling the housing to the mandrel; and means for secondarily coupling the housing to the mandrel in the event of failure of the primary coupling means.
[0019] In another embodiment, a method of receiving data from a wellbore, comprising: placing a gap sub assembly between an upper portion and a lower portion of a drill string, the gap sub assembly comprising: a housing; a mandrel; a dielectric material disposed between the housing and the mandrel; and a first non-conductive ring disposed between the housing and the mandrel; positioning the drill string and the gap sub assembly in the wellbore; energizing the upper portion and the lower portion of the drill string with opposite electrical polarity, thereby forming the electromagnetic wave; and measuring the electromagnetic wave at a predetermined point on the surface of the wellbore.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
[0021] FIG. 1 illustrates a drilling rig structure and an EM telemetry system utilizing a gap sub assembly of the present invention.
[0022] FIG. 2 illustrates a cross-sectional view of the gap sub assembly.
[0023] FIG. 2A illustrates an expanded view of dielectric filed threads in the gap sub assembly.
[0024] FIG. 2B illustrates an expanded view of an external gap ring disposed in the gap sub assembly.
[0025] FIG. 3 illustrates a cross-sectional view of the gap sub assembly.
[0026] FIG. 3A illustrates an expanded view of a non-conductive seal arrangement in the gap sub assembly.
[0027] FIG. 3B illustrates an expanded view of a plurality of torsion pins in the gap sub assembly.
[0028] FIG. 4 illustrates an expanded view of an alternative embodiment of the gap sub assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] Embodiments of the present invention generally provide a method and an apparatus for use in an EM telemetry system. For ease of explanation, the invention will be described generally in relation to drilling directional wells, but it should be understood, however, that the method and the apparatus are equally applicable in other telemetry applications. Furthermore, it should be noted that the principles of the present invention are applicable not only during drilling, but throughout the life of a wellbore such as logging, testing, completing, and producing the well.
[0030] FIG. 1 illustrates a drilling rig structure 40 and an EM telemetry system 100 utilizing a gap sub assembly 15 of the present invention. Generally, the EM telemetry system 100 may be used as a method to generate and receive the electromagnetic waves downhole. The method typically involves creating an electrical break between an upper section 10 and a lower section 20 of a drill string 60 to form a large antenna. The sections 10 , 20 of this antenna are energized with opposite electrical polarity, often using a modulated carrier wave that contains digital information which results in an EM wave 30 . Thereafter, the EM wave 30 travels through the earth to the surface where a potential difference may be measured between the rig structure 40 and a point 50 on the surface of the earth at a predetermined distance away from the rig.
[0031] In the embodiment illustrated, the electrical break in the drill string 60 is accomplished by a device referred to as the gap sub assembly 15 . Generally, the gap sub assembly 15 is an electrical isolation joint disposed between the upper and lower sections 10 , 20 of the drill string 60 . Preferably, the gap sub assembly 15 is constructed and arranged to carry high torsional, tensile, compressive, and bending loads.
[0032] It has been determined that the transmission efficiency of EM telemetry system 100 can be improved by increasing the non-conductive length of the gap on the exterior and interior in the range of 2-3″ or more, compared with a very small gap, in the range of 1/32″. The improvement is especially pronounced when the gap sub assembly 15 is immersed in conductive drilling fluids, as is often the case. The reason for this is that as the gap length is increased, the electrical resistance of the fluid path between the sections 10 , 20 increases, and more of the current flows through the formation and thus to the surface instead of through the fluid where it does not provide any transmission benefit.
[0033] FIG. 2 illustrates a cross-sectional view of the gap sub assembly 15 . As shown, the gap sub assembly 15 consists of a lower threaded member 101 which mates with a lower portion of the drill string (not shown) and an upper threaded member 102 which mates with an upper portion of the drill string. Alternatively, the gap sub assembly may be disposed in the drill string upside down. Disposed between the upper and lower threaded members 101 , 102 is a mandrel 104 , a housing 103 , and a first gap ring 105 .
[0034] The upper threaded member 102 and lower threaded member 101 serve as thread savers for the housing 103 and mandrel 104 . For instance under normal operating conditions, the upper threaded member 102 and lower threaded member 101 remain torqued up to the housing 103 and mandrel 104 respectively. Thereafter, exposed threads 113 and 114 are then used to attach the drill string above and below the gap sub assembly 15 . The sequence of mating and unmating of these threads is done frequently and causes wear which may require re-cutting the threads. Eventually when the upper threaded member 102 and the lower threaded member 101 become too short to further re-cut, they may easily be replaced without requiring the entire gap sub assembly 15 to be replaced. Alternatively, the housing 103 and the upper threaded member 102 may be formed as one-piece and the mandrel 104 and the lower threaded member 101 may also be formed as one-piece.
[0035] FIG. 2A illustrates an expanded view of dielectric filed threads 107 in the gap sub assembly 15 . As shown, the mandrel 104 contains an external threadform that has a larger than normal space 108 between adjacent threads. In the same manner, the housing 103 has an internal threadform with widely spaced threads 107 . The mandrel 104 and housing 103 are separated from each other by a dielectric material 109 , such as epoxy, which is capable of carrying axial and bending loads through the compression between adjacent threads. Typically, the load carrying ability of most dielectric materials is much higher in compression than tension and/or shear. In this respect, the total surface area bonded with the dielectric material 109 may also be increased dramatically over a purely cylindrical interface of the same length. Therefore, the increased surface area equates to higher strength in all loading scenarios.
[0036] Additionally, if the dielectric material 109 adhesive bonds fail and/or the dielectric material 109 can no longer carry adequate compressive loads due to excessive temperature or fluid invasion, the metal on metal engagement of the threads 107 prevents the gap sub assembly 15 from physically separating. Therefore, the mandrel 104 will remain axially coupled to the housing 103 and may be successfully retrieved from the wellbore.
[0037] FIG. 2B illustrates an expanded view of the first gap ring 105 disposed in the gap sub assembly 15 . In the preferred embodiment, the first gap ring 105 is constructed from a toughened ceramic material, such as yttria stabilized tetragonal zirconia polycrystals, as it is a highly abrasion resistant, as well as an impact resistant material. Zirconia also has an elastic modulus and thermal expansion co-efficient comparable to that of steel and an extremely high compressive strength (i.e. 290 ksi) in excess of the surrounding metal components. These properties allow the first gap ring 105 to support the joint under bending and compressive loading producing a significantly stronger and robust gap sub assembly 15 . One advantage of a first gap ring 105 over that of a coated annular disc is that coatings may become scratched revealing the conductive underlying material. Another advantage of the first gap ring 105 is that a non-porous surface is easily achieved, whereas suitable high temperature coatings, such as flame deposited ceramic are highly porous preventing their use generally as a reliable sealing surface.
[0038] In the preferred embodiment, a primary external seal 110 is formed by torquing the lower threaded member 101 onto the mandrel 104 to compress the first gap ring 105 between the two halves of the gap sub assembly 15 , thereby forming the primary external seal 110 on the faces of the first gap ring 105 . The combination of high compressive stress, good surface finish, and low porosity in the first gap ring 105 produces a high pressure, high temperature seal that is compatible with the entire range of drilling fluids. In addition to the stress required between faces to seal under no-load conditions, a higher compressive stress is required to maintain face to face contact during bending and/or tension.
[0039] In an alternative embodiment, the primary external seal 110 may be formed by mechanically stretching the mandrel 104 by the use of a hydraulic cylinder (not shown) or other device. Thereafter, as the mandrel 104 is maintained in the stretched condition, the lower threaded member 101 can be threadingly advanced until it is in contact with the external gap ring 105 , even though no significant torque has been applied. Upon releasing the stretch on the mandrel 104 , the high compressive forces on the faces of the first gap ring 105 forms the primary external seal 110 . In another alternative embodiment, the primary external seal 110 may be formed by cryogenically cooling the first gap ring 105 and subsequently mating the lower threaded member 101 thereto. As the first gap ring 105 warms up, it will expand creating the desired compressive forces to form the primary external seal 110 .
[0040] The use of the first gap ring 105 in the gap sub assembly 15 of the present invention may provide several advantages. A first advantage is that it forms a structural element supporting the gap sub assembly 15 in bending and compression. A second advantage is that it provides a significant non-conductive external length which is virtually impervious to abrasion. A third advantage is that the first gap ring 105 is the primary external seal compatible with the full chemical and temperature range of drilling fluids.
[0041] As further shown on FIG. 2B , a secondary seal arrangement is disposed adjacent the external gap ring 105 . The secondary seal arrangement includes a first sleeve 106 made from a high strength, high temperature plastic, such as PEEK and a series of elastomer seals 112 , 111 disposed on the interior of the housing 103 and the exterior of the mandrel 104 , respectfully. Preferably, the seals 112 , 111 prevent fluid from entering the space between the mandrel 104 and the housing 103 if the primary seal 110 should fail. Furthermore, the first sleeve 106 supports the first gap ring 105 and provides some shock absorption should the first gap ring 105 experience a severe lateral impact. In another aspect, the ability to remove the lower threaded member 101 easily allows the seals 112 , 111 and the first sleeve 106 to be inspected and replaced during a regular maintenance program.
[0042] FIG. 3 illustrates a cross-sectional view of the gap sub assembly 15 . FIG. 3A illustrates an expanded view of an internal, non-conductive seal arrangement 160 in the gap sub assembly 15 . Preferably, the internal, non-conductive seal arrangement 160 includes a second sleeve 151 formed from a high temperature, high strength dielectric material, such as PEEK, and a series of elastomer seals 155 , 156 disposed on the mandrel 104 and housing 103 respectively. Preferably, the elastomer seals 155 , 156 prevent drilling fluid from entering the internal space between mandrel 104 and housing 103 .
[0043] As further shown in FIG. 3A , a second, non-conductive gap ring 157 is provided in the bore of the gap sub assembly 15 to improve the electrical performance of the system. More specifically, as with the first gap ring 105 , the second, non-conductive gap ring 157 increases the path length that the current must flow through, thereby increasing the resistance of that path, and thus decreasing the unwanted current flow in the interior of the gap sub assembly 15 . In this manner, more of the current flows through the formation and thus to surface, instead of through the fluid where it does not provide any transmission benefit. Preferably, the second gap ring 157 is formed from a high temperature, high strength dielectric material, such as PEEK.
[0044] FIG. 3B illustrates an expanded view of the plurality of non conductive torsion pins 150 in the gap sub assembly 15 . The torsion pins 150 are constructed and arranged to ensure that no relative rotation between the mandrel 104 and housing 103 may occur, even if the dielectric material 109 bond fails. In the preferred embodiment, the torsion pins 150 are cylindrical pins disposed in matching machined grooves 154 and 153 . It is to be understood, however, that other forms of non-conductive devices may be employed such as non-conductive material forming keys in surrounding keyways, splines separated by a plastic insert, hexagonal sections separated by a non-conductive material, or a variety of other means known in the art to prevent rotation.
[0045] FIG. 4 illustrates an expanded view of an alternative embodiment 215 of the gap sub assembly 15 . Only a portion of the alternative gap sub assembly 215 is shown because the rest of the alternative gap sub assembly is identical to the gap sub assembly 15 . Parts that have not been substantially modified in this embodiment have retained the same reference numerals as that of gap sub assembly 15 . In this embodiment, a first compression ring 205 A is disposed between the housing 103 and the first gap ring 105 . Since the first compression ring 205 A radially extends to the mandrel 104 , the first sleeve 106 has been split into two pieces 206 A,B. A second compression ring 205 B is disposed between the first gap ring 105 and the lower threaded member 101 . Preferably, the compression rings 205 A,B are made from a relatively soft strain hardenable material, such as an aluminum and bronze alloy.
[0046] During testing of an embodiment of the gap sub assembly 15 , it was observed that when the preload was removed from the first gap ring 105 cracking resulted in the first gap ring 105 . Since the cracks did not form until the preload was removed, operation of the first gap ring 105 is unaffected. However, the cracks would necessitate replacement of the gap ring 105 possibly every time the gap sub assembly 15 is dismantled. This is undesirable from a cost perspective since the preferred zirconia material is relatively expensive. It is believed that the cracking stems from surface imperfections in ends of the housing 103 and the lower threaded member 101 facing respective ends of the first gap ring 105 . The relatively rough surface finish causes point loading between the first gap ring 105 and the housing 103 and lower threaded member 101 .
[0047] To mitigate the point loading effect, each end of the housing 103 and the member 101 facing the first gap ring 105 would have to be machined to a relatively fine surface finish. Machining the required surface finish would be time consuming and expensive. However, addition of the compression rings 205 A,B also mitigates the point loading effect. The preferred relatively soft material of the rings 205 A,B conforms to the surface imperfections in the first gap ring 105 as the connection is torqued, thereby distributing the load over the entire respective surfaces of the first gap ring. The compression rings 205 A,B will also preferably strain harden during torquing of the connection, thereby obtaining effects of increased strength and hardness which are beneficial to the service life of the compression rings. Therefore, compression rings 205 A,B provide a simple and inexpensive fix to the cracking problem. Further, it is believed that the compression rings 205 A,B may also minimize any torsional stress sustained by the first gap ring 105 .
[0048] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
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A compact, robust, wear resistant, and high performance electrically insulating gap sub for use with borehole EM Telemetry is disclosed. In one embodiment, the gap sub may include an externally threaded mandrel separated from an internally threaded housing by a dielectric material. Additionally, some embodiments may include an external gap ring for separating the upper and lower electrical halves of the sub which offers structural support, acts as the primary external seal, and provides an abrasion resistant non-conductive length on the exterior. Some embodiments may include torsion pins to prevent the possible unscrewing of the dielectric filled threaded sections should the dielectric material become damaged or weakened.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an apparatus and method for generating gravitational force/gravitational field. This may be used in the field of space travel, satellite positioning and orientation and in avionics where levitation is required to the low gravitational field of outer space.
[0003] 2. Description of the Related Art
[0004] The earth's gravitational field was discovered by Sir Isaac Newton in 1686, which was postulated as Newton's Law of Gravitation and expressed in the form of a mathematical equation.
[0005] In recent years numerous researchers have worked in the field of “antigravity” and the generation of an axial gravitational force/field by artificial methods in order to generate levitational effects at these sites. In general, levitation involves the use of a fundamental (non contact) force to balance gravity. Levitation is achieved in low gravitational forces of space, but can also occur in the presence of extremely intense fields such as electromagnetic, optical and acoustic levitation which have all been demonstrated.
[0006] Bettels et al (DE198,32001 A1 1998) describe the flow of electrons (current) in a rapidly rotating spiral form superconductor and a 2.5% reduction of the gravitational field above the superconductor.
[0007] Powerful superconducting magnets are commonly in use in England, Japan and Germany to guide and propel vehicles at high speed along a guide rail. Magnetic levitation has been achieved in these vehicles by the controlled use of magnetic forces to balance gravitational forces and hold the vehicle clear of the guide rail (for contactless, frictionless support). Further, electromagnetic induction driven coils disposed on opposing sides of the guide rail, alternate in polarity along the guide rail such that the current flows in the power coils and creates a magnetic field to interact with the vehicle superconducting magnets and provide thrust to the vehicle.
[0008] Acoustic levitation has been achieved by the use of intense acoustic waves to suspend a body which is immersed in a fluid medium without obvious mechanical support. Intense acoustic waves are nonlinear in their basic character and therefore may exert a net acoustic radiation pressure on an object sufficient to balance the gravitational force and thus levitate the body. The applications of acoustic levitation in air or other gas include an acoustic positioning module which is designed to be carried in the space shuttle and used in fundamental studies of oscillation and fission of spinning drops. An acoustic levitation furnace, also to be carried by the space shuttle, has been designed to study the possibility of containerless solidification of molten materials. This could result in materials of commercial interest, and lead to the bulk processing of materials in space.
[0009] The levitation of particles by light beams has been demonstrated in the field of quarks.
[0010] Artificial satellites, termed as geostationary satellites, which are in use for communication purposes for worldwide television, international telephonic traffic, facsimile, electronic mail services, etc. are increasingly of importance because no other wideband transmission system exists. The launch of these satellites in space and their position and orientation is achieved by disposable rockets. They are essentially in free fall because gravitational force is balanced by centrifugal force and normally have to be positioned at a height of 36,000 km above earth to cover the period of rotation exactly in 24 hours. If the gravitational force/field on them is reduced then they can be positioned at a distance of much less than 36,000 km to recieve better signal strength.
[0011] The newly concieved theory for gravitational force generation which has been implemented by way of laboratory experimentation postulates that a dipole charge in a dielectric, moving in a circular path in the presence of a radial magnetic field generates an axial gravitational force when it is subjected to the impulse of a current dipole.
[0012] The equal and opposite currents in two closely wound coils of high mutual coupling can generate a very high rate of change of magnetic flux between these coils and this changing flux causes the charge dipoles to vibrate which generates a very high frequency broad band radiation including the gravity band.
[0013] According to the said theory as concieved by the applicant, gravity is generated by the motion of an electron in its orbit, which is equivalent to the sinusoidal vibration of the charge dipole in three axes. Therefore, the vibration and the velocity of a charge dipole, generates gravity.
SUMMARY OF THE INVENTION
[0014] The first object of the invention is to provide an apparatus for generating gravitational force/field at ambient temperature or even at industrial temperature ranges without using any superconductor, acoustic or optical means.
[0015] Another object of the invention is to provide a method for generating gravitational force/field at ambient temperature or even at industrial temperature range without using any superconductor, acoustic or optical means.
[0016] The major components of the apparatus of the present invention comprise:
[0017] (a) a capacito inductor, which is a four terminal device giving the combined effect of capacitance and inductance;
[0018] (b) a permanent magnet synchronous motor;
[0019] (c) current pulse generator;
[0020] (d) magnetic circuit;
[0021] wherein the charge dipoles in the dielectric when oriented and vibrated in a radial magnetic field generate gravity.
[0022] Accordingly, the present invention provides an apparatus for generating gravitational force/gravitational field, said apparatus comprising a capacito-inductor, constituted by at least two coils, made of two metal layers with two dielectric layers provided therebetween, said coils being wound in predetermined turns on a cylindrical core of an insulating material; a magnet placed at the centre of said capacito-inductor for creating and passing radial magnetic field through the capacito-inductor; power supplies for applying equal and opposite current pulses at the end terminals of said two metal layers of the capacito-inductor, and also for applying predetermined voltage between the same end terminals of said metal layers; and a drive source for rotating the capacito-inductor, journalled between two covers; the arrangement being such that on high speed rotation of the capacito-inductor in the presence of the radial magnetic field, and on application of voltage at the same end terminals of the metal layers, charge dipole is caused to be oriented inside the dielectric layers in a radial direction with negative and positive charge directed towards the axis of rotation of the capacito-inductor in its alternate layers of dielectric, and with all the charge dipole being tilted towards the negative charge, either down or up, parallel to the axis of rotation, depending on the direction of rotation; and on application of equal and opposite current pulses between the end terminals of each of said metal layers, vibration is caused to be generated in the charge dipole, which, due to its rotation, generates gravitational force/field.
[0023] The invention further produces a method for generating gravitational force/gravitational field which comprises rotating at high speed a capacito-inductor constituted by at least two coils made of two metal layers with two dielectric layers provided therebetween, said coils being wound in predetermined turns on a cylindrical core of an insulating material with a magnet placed at the centre of said capacito-inductor, for creating and passing a radial magnetic field through the capacito-inductor, and simultaneously applying equal and opposite current pulses at the end terminals of said two metal layers of the capacito-inductor, and applying a predetermined voltage between the same end terminals of said metal layers, whereby the charge dipole is caused to be oriented inside the dielectric layers in a radial direction with negative and positive charges directed towards the axis of rotation of the capicito-inductor in its alternate layers of dielectric, with all the charge dipole being tilted towards the negative charge either down or up, parallel to the axis of rotation, depending on the axis of rotation, and vibration is caused to be generated in the charge dipole on the application of equal and opposite current pulses between the end terminals of each of said metal layers, resulting in generation of gravitational force/field.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] [0024]FIG. 1 shows an illustrative embodiment to explain the theory, based on which the apparatus according to the present invention has been designed and developed.
[0025] [0025]FIG. 2 shows, in symbolic representation, one embodiment of a capacito-inductor as used in the apparatus according to the present invention.
[0026] [0026]FIG. 3( a ) shows, in sectional view, one embodiment of the capacito-inductor, as used in the apparatus according to the present invention.
[0027] [0027]FIG. 3( b ) shows diagramatically the different layers of the capacito-inductor, as illustrated in FIG. 3( a ).
[0028] [0028]FIG. 4 diagramatically shows, in section, one embodiment of the apparatus according to the present invention and FIG. 5 shows, in block diagram, the interconnection amongst the various components of the embodiment of the present apparatus according to the present invention, as shown in FIG. 4.
[0029] FIGS. 6 ( a ) and 6 ( b ) show in sectional and plan views respectively one arrangement for generating magnetic field in the apparatus of the present invention.
[0030] FIGS. 7 ( a ) and 7 ( b ) show in sectional and plan views respectively another arrangement for generating magnetic field in the apparatus of the present invention.
[0031] FIGS. 8 ( a ) and 8 ( b ) show in sectional and plan views respectively a further arrangement for generating magnetic field in the apparatus of the present invention.
[0032] FIGS. 9 ( a ) and 9 ( b ) show in sectional and plan views respectively one more arrangement for generating magnetic field in the apparatus of the present invention.
[0033] [0033]FIG. 10 diagrammatically shows an embodiment of a capacito-inductor with more than four terminals, which may be used in the apparatus of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0034] In the capacito-inductor of the proposed apparatus, the metal layers are aluminium foils. Other metals may also be used. The dielectric may be polyester, but other dielectrics can be used. The cylindrical core is made of an insulating material like plastic. The thickness of the metal and dielectric layers is preferably in the range of 0.5 microns to 50 microns.
[0035] The inductance between the opposite terminals of the coils, as used in the apparatus of the instant invention, depends upon many factors like the number of turns, mean radius, width of coil and thickness of coil. It also depends upon metal thickness. It is proportional to the square of the number of turns, and it decreases as width or thickness is increased.
[0036] Inductance in a capacito-inductor is very important because magnetic energy is stored in the inductor and is given by:
E L =(1/2) LI 2
[0037] Where,
[0038] E L : The energy stored in the Inductor in Watt-sec
[0039] L: Inductance of the Inductor in Henry
[0040] I: Current in Ampere
[0041] This energy is in the form of a magnetic field. The rate of change of magnetic field creates vibrations of the charge dipole in the apparatus according to this invention. Therefore, inductance is very important.
[0042] It is to be understood that the construction of capacito-inductor is very close to that of capacitors. The capacito-inductor contains two metal layers and two dielectric layers. Therefore, all theories in manufacturing a capacitor are also applied here. The major difference between a capacitor and the proposed capacito-inductor is that capacitor is a two terminal device, while the capacito-inductor is a four terminal device. It is to be understood further that in good capacitors the inductance of metal layer is kept minimum to have better performance, while in the case of the proposed capacito-inductor the inductance is very important, as explained hereinbefore. In capacitors one connection is taken from the middle of the length of the metal layer to minimize the effect of inductance, while in case of the capacito-inductor there are two connections at both ends of each metal layer. The capacitance is proportional to the area of the metal surface and the dielectric constant, while it is inversely proportional to the thickness of the dielectric or the distance between the metal layers.
[0043] The two coils of the capacito-inductor are mutually coupled with the same end terminals in the same direction. The said mutual coupling can be explained by a transformer action. As it is known, all transformers work on mutual coupling, which is more if the two coils of the transformer are closely wound. As a preferred embodiment, more than four terminals are provided in the capacito-inductor by employing a corresponding number of coils and capacitors, said coils being connected either in series or parallel.
[0044] In the apparatus of this invention the magnet is placed at the centre of the capacito-inductor, ensuring that a radial magnetic flux passes through the capacito-inductor.
[0045] An iron cylinder may be used to improve the radial magnetic flux, as will be explained hereinafter with the help of the illustrative drawings. So, there can be different ways to make the magnetic circuit but the radial magnetic field should pass through the capacito-inductor. A magnetic field with radial and tangential components gives better results.
[0046] With reference to FIG. 1, if it is considered that two hydrogen atoms ( 34 ) and ( 35 ) are placed at a distance d ( 29 ), the force vector between two protons ( 38 ) and ( 39 ) is F 1 ( 30 ), which is a force of repulsion. The force vector between two electrons ( 36 ) and ( 37 ) is F 2 ( 31 ). The force vector between the first electron ( 36 ) and the second proton ( 39 ) is F 3 ( 32 ). The force vector between the first proton ( 38 ) and the second electron ( 37 ) is F 4 ( 33 ), as shown in FIG. 1. As the electrons ( 36 ) and ( 37 ) are moving around the nucleus, the force F 2 ( 31 ), F 3 ( 32 ) and F 4 ( 33 ) will change continuously.
[0047] The resultant force Fe can be deduced to be:
Fe=F 1 ( 30 )+F 2 ( 31 )+ F 3 ( 32 )+ F 4 ( 33 )
[0048] This resultant force Fe is nothing but the electrostatic force vector of gravitation force. Similarly, there is a resultant force Fm which can be calculated and this is the magnetic force vector of gravitation force. The gravitational force is the resultant vector of these two forces.
[0049] Hence, gravitation force, Fg=Fe+Fm
[0050] The probability of finding an electron in spherical co-ordinates is not uniform, and it changes significantly with distance, which effects the resultant force Fe. The probability of finding the electron is dependent on the force applied on it, and the force is dependent on its position. The average value of resultant force Fe is not ZERO, and it is positive in all elements of matter. It was solved with certain assumptions for the distance “d” ( 29 ) between the atoms, ranging from 10E-6 m to 10E+7 m by a special custom built software of mathematical accuracy greater than 200 digits. It has been observed that the answer is never zero.
[0051] A simple analogy is that if there is one voltage source of 1000 V DC and another source of 1000V DC having a ripple of 1 volt then the average voltage of both the sources will be 1000 V. However, the RMS voltage in the second source will be more than that of the first source, and difference between these two voltage sources will not be zero. The RMS value is always, greater or equal to the average value. Therefore, the resultant force Fg (gravitation force) will not be zero even at higher distances based on the above explanation.
[0052] From the above, it has been concluded that gravitational force is an electromagnetic force (or electromagnetic wave), which is generated by motion of charge in matter. The resultant force Fg is always positive, as explained hereinbefore. So, gravitational force is always a force of attraction. Also, Fe (electrostatic force vector of gravitation) is the sum of four electrostatic forces, of which two are positive and two are negative. Therefore, the resultant force Fg is significantly weak compared to the electrostatic force F 1 ( 30 ).
[0053] As stated hereinbefore, the probability of finding an electron in spherical coordinates is not uniform, and it varies with distance. Its variations (non-uniformity) are more at shorter distances, which means that motion of electron is more restricted at shorter distances. This reduces the kinetic energy of electrons at shorter distances. As the distance is increased, the kinetic energy of electrons is also increased, because of more uniform probability. The difference in KE of electrons at different distance is the gravitational potential energy.
[0054] It has also been concluded that the product of vibrating charge dipole and velocity is gravitation, which is analogous to the theory of magnetism, which says that the product of charge and velocity is magnetism. As explained hereinbefore, rotational motion is equivalent to sinusoidal vibrations in the three axes. Thus, the gravitational field generated will not be omni-directional but will have a specific direction.
[0055] Based on the aforementioned theory, it has been found by the applicant herein that the gravity can be generated with the help of a newly invented electrical component, termed as capacito-inductor ( 14 ) which is a four terminal device and generates the combined effect of capacitance and inductance. Such a device with more than 4 terminals will give better results, as illustrated in FIG. 10 of the drawings accompanying this Specification.
[0056] As shown in FIG. 2, the capacito-inductor is constituted by two coils having terminals A( 1 ), B( 2 ) and C( 3 ), D( 4 ), which offer inductance L between A( 1 ) to B( 2 ), and C( 3 ) to D( 4 ). It also has sufficient capacitance between A( 1 ) to C( 3 ) or B( 2 ) to D( 4 ). Its inductance is very small at A( 1 ) to C( 3 ) when B( 2 ) and D( 4 ) are shorted. It is used as the main component for generating gravitational force, by the proposed apparatus, to be described hereinafter with reference to the accompanying drawings. As shown in FIG. 2, equal and opposite current pulses ( 5 and 6 ) are applied between the terminals D to C and A to B of the two coils, and voltage ( 7 ) is applied between the same end terminals A and C of the two coils. Mutual coupling between the two coils, as explained hereinbefore, is indicated by ( 8 ). In the illustrative embodiment of the capacito-inductor, shown in FIG. 10, there are used more than four terminals, by employing coils L 1 , L 2 , L 3 and L 4 and capacitors C/ 2 .
[0057] L 1 and L 2 can be connected either in series or in parallel. Similarly L 3 and L 4 can also be connected.
[0058] More than four terminals in a capacito-inductor will change the impedance of the circuit. This helps in matching the impedance of a current pulse generator.
[0059] As shown in FIGS. 3 ( a ) and 3 ( b ), the capacito-inductor has:
[0060] (a) Core ( 9 );
[0061] (b) Metal foil Layer ( 10 );
[0062] (c) Dielectric film Layer ( 11 );
[0063] (d) Metal foil Layer ( 12 );
[0064] (e) Dielectric film Layer ( 13 ).
[0065] With the help of the said capacito-inductor the generation of gravity can be controlled by the following control parameters:
[0066] (i) Applied voltage-V ( 7 );
[0067] Function: To orient the charge dipoles inside dielectric;
[0068] (ii) Current ( 6 ) through metal layer ( 10 ) and Current ( 5 ) through metal layer ( 12 );
[0069] Function: To vibrate the charge dipoles;
[0070] (iii) Angular frequency —ω;
[0071] Function: To give velocity to the charge dipoles;
[0072] (iv) Superimposed vibration amplitude—A;
[0073] Function: To compensate the eccentricity of capacito-inductor rotation;
[0074] (v) Radial magnetic field Intensity—B;
[0075] Function: To tilt the charge dipoles
[0076] (vi) Design parameters of capacito-inductor ( 14 ):
[0077] Dielectric Constant—K,
[0078] Number of turns N,
[0079] Dielectric Thickness—d,
[0080] Internal Diameter—ID,
[0081] Outer Diameter—OD.
[0082] It is, therefore, clear that the capacito-inductor ( 14 ) is a four-layer device with metal foil ( 10 )-dielectric film ( 11 )-metal foil ( 12 )-dielectric film ( 13 ), wound on a cylindrical core ( 9 ) as shown in FIGS. 3 ( a ) and 3 ( b ). The first layer of the metal film ( 10 ) is having its ends as the two terminals of the device i.e. A( 1 ) and B( 2 ), while the second layer of metal film ( 12 ) has its ends as other two terminals of the device i.e. C( 3 ) and D( 4 ). These two metal layers have dielectric film layers ( 11 ) and ( 13 ) in between, as shown in FIG. 3( b ).
[0083] The apparatus according to the present invention, for generating gravitational force/gravitational field, has the following essential constructional features, as shown in FIG. 4:
[0084] (i) Capacito-inductor ( 14 );
[0085] (ii) Stator of a permanent magnet synchronous motor (PMSM) ( 15 );
[0086] (iii) Slip-rings ( 16 ) of slip-ring assembly;
[0087] (iv) Top cover ( 17 );
[0088] (v) Contacts ( 18 ) of slip-ring assembly;
[0089] (vi) Magnet ( 19 ) for synchronous motor;
[0090] (vii) PCB (Printed circuit board) ( 20 ) for current pulse generator;
[0091] (viii) Magnet ( 21 ) to create radial magnetic field;
[0092] (ix) Bottom cover ( 22 ).
[0093] In the operation of the apparatus according to the present invention, the magnetic rotor ( 19 ) of PMSM ( 15 ) rotates all the moving parts including the capacito-inductor ( 14 ), PCB ( 20 ) and slip-rings ( 16 ). The magnet ( 21 ) creates a radial magnetic field. Electronic PCB ( 20 ) is also mounted on the rotating system and optically couples the two current pulse generators. The slip-ring assembly ( 16 and 18 ) is mounted above the PMSM ( 15 ) to feed power to electronic PCB. The whole system is covered with the help of the top ( 17 ) and bottom ( 22 ) covers, as shown in FIG. 4.
[0094] The diverse arrangements for generating magnetic field have been illustrated in FIGS. 6 ( a ), 6 ( b ), 7 ( a ), 7 ( b ), 8 ( a ), 8 ( b ), 9 ( a ) and 9 ( b ) of the drawings accompanying this complete specification. In all the said figures magnets are denoted by ( 40 ), iron cores by ( 41 ), and iron cylinder by ( 42 ). In FIG. 8( a ) radial magnetic flux is indicated by ( 43 ). The arrangement of FIGS. 8 ( a ) and 8 ( b ) increases the flux and that makes it more radial because path reluctance is reduced. The arrangement of the magnetic circuit shown in FIGS. 9 ( a ) and 9 ( b ) yields comparatively better magnetic flux.
[0095] As shown in FIG. 5 of the drawings, the apparatus according to the present invention can be caused to be operated/actuated by means of the following features and in the following manner:
[0096] (a) First power supply ( 23 ) to feed power to PCB for current pulse generator ( 27 );
[0097] (b) Second power supply ( 24 ) to apply voltage V ( 7 ) on the capacito-inductor ( 14 );
[0098] (c) Third power supply ( 25 ) to feed power to PCB for current pulse generator ( 28 );
[0099] (d) Slip-rings ( 26 ) to transfer power to rotating PCB;
[0100] (e) Current pulse generator ( 27 ) to generate current pulses ( 5 );
[0101] (f) Current pulse generator ( 28 ) to generate current pulses ( 6 ).
[0102] The Voltage ( 7 ) is applied at the terminal A( 1 ) and C( 3 ) of the coils of the capacito-inductor ( 14 ) through the power supply ( 24 ). Equal and opposite current pulses are applied at the terminals A( 1 )-B( 2 ) and C( 3 )-D( 4 ) of the capacito-inductor ( 14 ) with the help of two current pulse generators ( 28 ) and ( 27 ) respectively. These two current pulse generators are opto-coupled to generate almost equal and opposite current pulses.
[0103] The second current pulse generator ( 27 ) may be eliminated by short circuiting the terminals C( 3 ) and D( 4 ). In that case, due to high mutual inductance between the two coils A( 1 )-B( 2 ) and C( 3 )-D( 4 ) almost equal and opposite current is generated in both the coils with only one current pulse generator ( 28 ).
[0104] It would therefore, be appreciated that the essential and significant component of the apparatus according to the present invention is a four-layer device with metal ( 10 )-dielectric ( 11 )-metal ( 12 )-dielectric ( 13 ) wound on a cylindrical core ( 9 ). It is a four terminal device A( 1 ), B( 2 ), C( 3 ), D( 4 ) which offers inductance between A( 1 ) to B( 2 ) and C( 3 ) to D( 4 ). It also has sufficient capacitance between A( 1 ) to C( 3 ) or B( 2 ) to D( 4 ). However, its inductance is very small at A( 1 ) to C( 3 ) when B( 2 ) and D( 4 ) are shorted. It has been termed as capacito-inductor ( 14 ). It is placed within a magnetic circuit of permanent magnet ( 21 ) which creates radial and tangential magnetic field, as explained. When the capacito-inductor is caused to be rotated at high speed, and voltage ( 7 ) is applied between A( 1 ) and C( 3 ), and also opposite current (dipole current) pulses ( 6 ) and ( 5 ) are applied on the terminal ends A( 1 )-B( 2 ) and C( 3 )-D( 4 ) respectively, axial gravitational field is generated. A PMSM ( 15 and 19 ), used to rotate the capacito-inductor ( 14 ), is controlled with the help of a separate electronic controller. The applied voltage ( 7 ) orients charge dipole inside dielectric in radial direction with negative and positive charge towards axis of rotation in alternate layers of dielectric. Rotation of the capacito-inductor ( 14 ) in presence of radial and tangential magnetic field tilts all the charge dipole towards negative charge, either down or up, parallel to axis of rotation, depending upon the direction of rotation. As force vector on positive and negative charge is equal and opposite, the resultant effect is torque on charge dipole. The current dipole pulses generate vibration in charge dipole, and rotation of this charge dipole generates gravity.
EXAMPLES
[0105] Test results as achieved from some of the embodiments of the apparatus according to the present invention
Prototype “A”
[0106] ID=62 mm, OD=120 mm, 25 um Polyester, 4.5 um Aluminum, N=453
[0107] RAB=6.3E, C=32 uF
[0108] Weight of Prototype=10 Kg
[0109] Deflection sensitivity of test stand=17 gram/mm
[0110] Rotation speed=2800 to 2900 RPM
[0111] Current pulses of peak current 6 A approx., Radial magnetic field is applied
[0112] DC Voltage between A and C=0 to 700 V
[0113] Speed(rpm) 0 2500 2860 3100 3262 3330 2954 2868
[0114] Pointer 151 151 152 152 151.5 150.8 151.5 151.5
[0115] Voltage(DC) 0 750 0 750
[0116] Pointer 151 151.5-152 151 151.5
[0117] This shows 0.5 mm deflection in the direction of weight decrease which is equivalent to 0.05% weight reduction.
Prototype “B”
[0118] ID=62 mm, OD=200 mm, 15 um Polyester, 6 um Aluminum, N-1760
[0119] R AB =30E, L AB =0.256 H, Capacitance is not measurable correctly by simple
[0120] capacitance meter because of high inductance.
[0121] Weight of Prototype=18.9 Kg
[0122] Deflection sensitivity of test stand=35 gram/mm
[0123] Rotation speed=800 to 2000 RPM
[0124] Current pulses of peak current 2.5 A approx., Radial magnetic field is applied.
[0125] DC Voltage between A and C=0 to 100V Deflection due to weight reduction=0.4 to 0.5 mm. The deflection was reduced to 0.3 mm after trials of one day. However it showed a weight reduction of 0.05%.
[0126] It is to be understood that various embodiments of the apparatus according to the present invention are possible within the scope of what has been described hereinbefore, and will be claimed hereinafter.
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There is disclosed an apparatus for generating gravitational force/gravitational field, which, for example, may be used in space and avionics applications, said apparatus comprising a capacito-inductor, constituted by at least two coils, made of two metal layers with two dielectric layers provided therebetween, said coils being wound in predetermined turns on a cylindrical core of an insulating material; a magnet placed at the center of said capacito-inductor for creating and passing radial magnetic field through the capacito-inductor; power supplies for applying equal and opposite current pulses at the end terminals of said two metal layers of the capacito-inductor, and also for applying predetermined voltage between the same end terminals of said metal layers; and a drive source for rotating the capacito-inductor, journalled between two covers.
Also disclosed a method of generating gravitational force/field by using said capacito-inductor.
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[0001] This application is based on an claims a priority from a Japanese Patent Application No. 2006-157713 filed on Jun. 6, 2006, the entire content of which are incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a vehicle steering system for moving a vehicle in a desired direction, and more particularly to a vehicle steering system which can perform an automatic steering to park the vehicle in a desired parking position.
[0003] A technique is proposed in JP-A-5-58319 in which an automatic driving of a vehicle is realized by an automatic steering system and an automatic control is performed when the traveling vehicle is expected to contact with an obstacle.
[0004] In addition, a technique is disclosed in JP-A-10-114272 and JP-A-2006-21722 in which a vehicle steering system is automatically controlled so that a vehicle is guided to a parking position when a parking from back or parallel parking is performed.
[0005] In order to realize the automatic driving of the vehicle by the automatic steering system, various types of vehicle sensors are necessary for detecting driving conditions and behaviors of the vehicle. As for the vehicle sensors, since the behavior of the vehicle differs remarkably between when the vehicle is driven at relatively high speeds and when the vehicle is driven to be parked, separate vehicle sensors are necessary for vehicle sensors for the relatively high-speed driving such as those disclosed in JP-A-5-58319 and vehicle sensors for automatic parking control such as those disclosed in JP-A-10-114272 and JP-A-2006-21722.
[0006] In this way, many vehicle sensors have to be provided on the vehicle, and moreover, separate vehicle sensors which are different in sensitivity from one another are necessary for the relatively high-speed running and the automatic parking control which is performed at low speeds. Accordingly, this situation has caused a problem that the realization of the automatic steering is extremely difficult.
SUMMARY OF THE INVENTION
[0007] The invention has been made in these situations, and an object thereof is to provide a vehicle steering system in which detection outputs of vehicle sensors are switched so as to be used appropriately for automatic driving control when a automatic driving control is performed by the vehicle steering system.
[0008] In addition, another object of the invention is to provide a vehicle steering system which can realize an automatic parking control by making effective use of outputs of vehicle sensors such as a yaw rate sensor and/or a lateral acceleration sensor for detecting a behavior of a vehicle when the vehicle is driven at high speeds.
[0009] With a view to attaining the objects of the invention, according to a first aspect of the invention, there is provided a vehicle steering system comprising:
[0010] a control member that is manipulated by a driver for controlling a direction of a vehicle;
[0011] a steering mechanism that turns steered road wheels in response to manipulation of the control member;
[0012] an automatic driving mode setting unit that enables an automatic driving control for an automatic driving mode;
[0013] a plurality of vehicle sensors for detecting various kinds of information which represent behaviors of the vehicle;
[0014] an output gain switch that switches an output gain for a predetermined vehicle sensor of the plurality of vehicle sensors so as to output an appropriate output for the automatic driving mode in response to setting of the automatic driving mode by the automatic driving mode setting unit; and
[0015] an automatic steering controller that automatically controls the steering mechanism while referring to outputs of the plurality of vehicle sensors in the automatic driving mode.
[0016] According to a second aspect of the invention, there is provided a vehicle steering system as set forth in the first aspect of the invention, in which the automatic driving mode is an automatic parking control mode, and the vehicle sensor whose output gain is switched by the output gain switch includes a yaw rate sensor for detecting a yaw rate of the vehicle so that the output gain is switched in such a manner as to increase a resolution in a low speed area.
[0017] In the configurations described above, when the driver manipulates the control member, the steered road wheels are turned by the steering mechanism so that the vehicle can be steered in a desired direction.
[0018] In addition, when the driver manipulates the automatic driving mode setting unit, a state can be produced in which the automatic driving control or, for example, the automatic parking control is performed. In the automatic parking control, the steered road wheels are turned by the automatic steering control units so that the vehicle is moved to a predetermined parking position.
[0019] While the plurality of vehicle sensors are provided on the vehicle for detecting the behavior of the vehicle, the output gain of the predetermined vehicle sensor of the plurality of vehicle sensors is switched by the gain switching unit at the time of automatic parking control.
[0020] For example, an output gain of the yaw rate sensor for detecting the yaw rate of the vehicle is determined such that an effective detection output is led out within a vehicle driving speed range of, for example, 0 to 150 km/h.
[0021] In the automatic parking control, however, since the driving speed of the vehicle is on the order of 10 km/h or slower at the fastest, the output range of the yaw rate sensor is limited to a narrow range for low speeds.
[0022] Then, the gain of a detection output of the yaw rate sensor is switched by the gain switching unit at the time of automatic parking control, so that the resolution of a detection output which results when the driving speed is, for example, 10 km/h or slower is increased.
[0023] By this configuration, the detection output of the yaw rate sensor can be made use of in a more effective fashion so as to be reflected on the automatic parking control of the vehicle.
[0024] While in the above description, the yaw rate sensor is described as an example of the vehicle sensor whose output gain is switched by the gain switching unit, the relevant vehicle sensor is not limited to the yaw rate sensor, and hence, other vehicle sensors than the yaw rate sensor such as a lateral acceleration sensor, a vehicle speed sensor and the like can be raised as the vehicle sensor whose output gain is so switched.
[0025] In addition, while in the above description, the invention is described as being applied to the automatic parking control, the application of the invention is not limited to the control at the time of parking, and hence, the invention can also be applied to an automatic driving control when the vehicle is driven at high speeds.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is an illustration drawing which illustrates the configuration of a vehicle steering system according to an embodiment of the invention.
[0027] FIG. 2 is a block diagram illustration which illustrates the switching of an output gain of a yaw rate sensor 16 which is given to a control unit 20 .
[0028] FIG. 3 are graphs showing sensor output characteristics.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0029] Hereinafter, an embodiment of the invention will be described in detail with reference to the accompanying drawings.
[0030] FIG. 1 is an illustration drawing which illustrates a configuration of a vehicle steering system according to an embodiment of the invention, and in the drawing, a configuration of a so-called steer-by-wire system is shown. The vehicle steering system includes a steering wheel 1 which is a control member that is manipulated by a driver for controlling the direction of the vehicle, a steering actuator 2 which is driven in response to rotational manipulation of the steering wheel 1 and a steering gear 3 which transmits the driving force of the steering actuator 2 to, for example, front left and right road wheels 4 as steered road wheels. A mechanical connection for mechanically transmitting a steering torque applied to the steering wheel 1 to the steering mechanism 5 is not provided between the steering wheel 1 and a steering mechanism 5 including the steering actuator 2 , and the steering actuator 2 is controlled to be driven according to a manipulation amount (a manipulation angle or manipulating torque) of the steering wheel 1 , so as to turn the road wheels 4 .
[0031] The steering actuator 2 can be made up of an electric motor such as a known brushless motor. The steering gear 3 has a motion transforming mechanism for transforming a rotational motion of an output shaft of the steering actuator 2 into linear motions (linear motions in lateral directions of the vehicle) of steering rods 7 . The movements of the steering rods 7 are transmitted to the road wheels 4 via tie rods 8 and knuckle arms 9 , so as to change toe angles (turning angles) of the road wheels 4 . A known steering gear can be used for the steering gear 3 , and there is no limitation on the configuration thereof, provided that the movement of the steering actuator 2 can be transmitted to the road wheels 4 in such a manner as to change the turning angles thereof. In addition, a wheel alignment is set such that the road wheels can returns to a straight-ahead position by a self aligning torque in a state that the steering actuator 2 is not driven.
[0032] The steering wheel 1 is connected to a rotational shaft 10 which is supported rotatably on a vehicle body side. A counterforce actuator 19 is provided on the rotational shaft 10 for generating a counterforce to be applied to the steering wheel 1 . The counterforce actuator 19 can be made up of an electric motor such as a brushless motor which has an output shaft which is integrated with the rotational shaft 10 .
[0033] An elastic member 30 is provided between the vehicle body and the rotational shaft 10 for applying an elastic force in a direction in which the steering wheel 1 is caused to turn back to the straight-ahead steering position. The elastic member 30 can be made up of, for example, a spring for applying an elastic force to the rotational shaft 10 . When no torque is applied to the rotational shaft 10 by the counterforce actuator 19 , the steering wheel 1 is allowed to turn back to the straight-ahead steering position by virtue of the elastic force of the elastic member 30 .
[0034] An angle sensor 11 is provided for detecting a rotational angle δh of the rotational shaft 10 in order to detect a manipulation angle (a rotational angle) of the steering wheel 1 . In addition, a torque sensor 12 is provided for detecting a torque transmitted by the rotational shaft 10 in order to detect a manipulation torque Th which is applied to the steering wheel 1 by the driver. Furthermore, a steered angle sensor 13 for detecting a steered angle (a turning angle produced by the steering mechanism 5 ) δ of the vehicle is made up of a potentiometer for detecting an operation amount of the steering rods 7 which correspond to the steered angle of the vehicle. In addition, a speed sensor 14 for detecting a vehicle velocity V, a lateral acceleration sensor 15 for detecting a lateral acceleration Gy of the vehicle and a yaw rate sensor 16 for detecting a yaw rate γ of the vehicle are provided to the vehicle.
[0035] Furthermore, a rearview monitor camera 17 for picking up a rearview at the rear of the vehicle and an obstacle sensor 18 for emitting detection signals (for example, infrared rays or ultrasonic waves) to sides and obliquely rearward directions of the vehicle to sense obstacles lying to sides of the vehicle and in obliquely rearward positions of the vehicle and to detect distances to those obstacles so sensed are provided to the vehicle.
[0036] The angle sensor 11 , torque sensor 12 , steered angle sensor 13 , speed sensor 14 , lateral acceleration sensor 15 and yaw rate sensor 16 are connected to a control unit 20 which is made up of a computer. The control unit 20 is configured to control the steering actuator 2 and the counterforce actuator 19 via drive circuits 22 , 23 .
[0037] In addition, an automatic driving mode setting switch 21 is provided in a position where the driver can manipulate the switch.
[0038] When the automatic driving mode setting switch 21 is switched on, a signal which represents that the automatic driving mode setting switch 21 is on is given to the control unit 20 , whereby the vehicle steering system is then automatically controlled by the control unit 20 . In the case of an automatic parking mode, detection outputs of the rearview monitor camera 17 and the obstacle sensor 18 are effectively used. As an example, FIG. 2 shows an illustration of a block diagram which illustrates switching of an output gain of the yaw rate sensor 16 which is given to the control unit 20 . A yaw rate γ of the vehicle which is detected by the yaw rate sensor 16 is switched to be given to an amplifier circuit 202 or an amplifier circuit 203 by a selector switch 201 in the control unit 20 . The amplifier circuit 202 has an amplification factor of a predetermined relatively small gain G 1 , while the amplifier circuit 203 has an amplification factor of a predetermined relatively large gain G 2 (G 2 >G 1 ).
[0039] A yaw rate γ 1 or γ 2 which is amplified at the amplifier circuit 202 or 203 is converted from an analog signal to a digital signal by an A/D converter circuit 204 and is then given to an MPU (micro processing unit) 205 .
[0040] A more specific description will be made with reference to sensor output characteristics shown in FIG. 3 , as well.
[0041] The vehicle steering system shown in FIG. 1 is normally in a steer-by-wire mode, and the drive circuits 22 , 23 are controlled so as to output steering forces suitable for the steer-by-wire mode by the control unit 20 . In this case, the switch 201 is switched so that the yaw rate γ which is detected by the yaw rate sensor 16 is given to the amplifier circuit 202 , and the yaw rate γ 1 which is amplified by the gain G 1 exhibits an output characteristic shown in Example 0 of FIG. 3A , for example. Namely, the yaw rate γ 1 is amplified so that yaw rate and voltage are associated with each other in such a manner that an output of “5V” can be obtained with an input of “10.”
[0042] On the other hand, when the automatic parking mode setting switch 21 is switched on so that the vehicle steering system is in the automatic parking mode, the switch 201 is switched so that the output γ of the yaw rate sensor 16 is given to the amplifier circuit 203 and is then amplified by the gain G 2 , so as to obtain a yaw rate of γ 2 .
[0043] The yaw rate γ 2 has a characteristic shown, for example, in Example 1 of FIG. 3 and is associated in such a manner that an output of “5V” can be obtained with an input of “5.”
[0044] Namely, the output characteristic of the sensor shown in Example 1 of FIG. 3 have a double sensitivity (resolution) when compared to the output characteristic of the sensor shown in Example 0 of FIG. 3 . More specifically, while the detection range (working range) of the sensor is narrowed to one half, but the resolution is doubled.
[0045] Normally, in the automatic parking mode, the driving speed of the vehicle is slow or low to be 10 km/h or slower, and the yaw rate (speed at which the orientation of the vehicle changes) is relatively moderate. Therefore, even in the event that the working range of the yaw rate sensor 16 is narrowed, for example, to one half, there is caused no problem in detecting a yaw rate. Then, an output which is more suitable for the automatic parking mode is obtained by making the resolution of the sensor double while the working range of the sensor is narrowed to one half.
[0046] As a modification of the above embodiment, another configuration in which an output of the yaw rate sensor is switched between a normal mode and the automatic parking mode can be adopted. Specifically, the switching is determined based on which of the two tables 206 , 207 installed in the MPU 205 is used. The MPU 205 includes a data conversion table 206 which corresponds to the gain G 1 and a data conversion table 207 which corresponds to the gain G 2 . At the MPU 205 , the corresponding table 206 or 207 is applied to a yaw rate so inputted thereinto for gain conversion.
[0047] In FIG. 2 , the output γ of the yaw rate sensor 16 is given to the MPU 205 by way of the amplifier circuit 202 irrespective of the signal from the automatic driving mode switch 21 . In this case, when the MPU 205 obtains a sensor output by applying the table 206 to the yaw rate γ 1 given thereto, for example, the output characteristic shown in Example 0 of FIG. 3 is obtained.
[0048] On the other hand, the table 207 is applied to the yaw rate γ 1 so as to obtain a sensor output in the automatic parking mode, whereby an output characteristic shown in Example 2 of FIG. 3 is obtained.
[0049] The output characteristic shown in Example 2 of FIG. 3 is an output characteristic in which the resolution near a rotational angle of 0° on a positive side is increased.
[0050] In this way, taking the output of the yaw rate sensor 16 for example, one of features of the embodiment is that the amplifier circuits 202 , 203 or the tables 206 , 207 which can be switched between the normal mode and the automatic parking mode so as to optimize the output of the yaw rate sensor 16 to necessary output ranges for the respective modes is provided.
[0051] Incidentally, while in the configuration of the block diagram illustration shown in FIG. 2 , the selector switch 201 , the amplifier circuit 202 and the amplifier circuit 203 are provided and the table 206 and the table 207 are included, a configuration may be adopted in which for example, only either the switch and circuits or the tables are provided, for example, the selector switch 201 , the amplifier circuit 202 and the amplifier circuit 203 are provided and the tables 206 , 207 are omitted, or a configuration may be adopted in which the selector switch 201 , the amplifier circuit 202 and the amplifier circuit 203 are excluded from the configuration shown in the block diagram of FIG. 2 .
[0052] While in the description that has been made heretofore, the invention is described by taking the yaw rate sensor 16 for example embodiment, the vehicle sensors other than the yaw rate sensor 16 such as the lateral acceleration sensor 15 , the vehicle speed sensor 14 , a throttle position sensor and the like can be raised, for example, as sensors whose detection outputs are preferably switched between the normal mode and the automatic parking mode.
[0053] In addition, while in the embodiment, the output gain of the sensor is described as being switched between the normal mode and the automatic parking mode, the output gain of the sensor may be made to be switched between the normal mode and, for example, an automatic driving control mode. For example, when the vehicle enters a high-way driving state, the vehicle steering system can be made to be switched from the normal mode to the automatic driving control mode, so as to increase a detecting resolution for a steering angle δh of the steering wheel 1 which is detected by the angle sensor 11 (refer to FIG. 1 ) for detecting a rotational angle of the rotational shaft 10 , whereby the detection accuracy within a small steering angle range is increased for stabilizing control of the behavior of the vehicle, or the same can be made use of in order to enhance the accuracy of a lane keeping control of the vehicle.
[0054] Furthermore, while in the embodiment, the invention is described as being applied to the steer-by-wire system, the invention can widely be applied to vehicle steering systems in which the steering actuator for imparting steering force to the steering mechanism of the vehicle is provided. Vehicle steering systems like this include an electric power steering system, a hydraulic steering system and the like.
[0055] The embodiments described above are to be regard as illustrative rather than restrictive. Variations and changes may be made by others, and equivalents employed, without departing from spirit of the present invention. Accordingly, it is intended that all variation, changes and equivalents which fall within the spirit and scope of the present invention as defined in the claims be embraced thereby.
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A vehicle steering system includes: a control member that is manipulated by a driver for controlling a direction of a vehicle; a steering mechanism that turns steered road wheels in response to manipulation of the control member; an automatic driving mode setting unit that enables an automatic driving control for an automatic driving mode; a plurality of vehicle sensors for detecting various kinds of information which represent behaviors of the vehicle; an output gain switch that switches an output gain for a predetermined vehicle sensor of the plurality of vehicle sensors so as to output an appropriate output for the automatic driving mode in response to setting of the automatic driving mode by the automatic driving mode setting unit; and an automatic steering controller that automatically controls the steering mechanism while referring to outputs of the plurality of vehicle sensors in the automatic driving mode.
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BACKGROUND OF THE INVENTION
a) Field of the Invention
The present invention pertains to an apparatus for determining the state of combustion within internal combustion engines which use an ignition coil as part of its ignition system.
b) Description of Related Art
A known ignition system for internal combustion engines is shown in FIG. 5. The system includes an ignition coil 10 having a primary winding 12 and a secondary winding 14. On the primary side of the ignition coil 10, a power supply unit 2 is connected to a first end of the primary winding 12 and an ignition timing control means 4 is connected to a second end of the primary winding 12, thereby forming the primary circuit. A known ignition timing control means 4 includes a transistor with the collector connected to the second end of the primary winding 12, the emitter connected to ground, and the base connected to an ignition signal input port 6. On the secondary side of the ignition coil 10, spark plug gaps 20,22 are provided between the secondary winding 14 and ground.
The known ignition system operates when the primary side of the ignition coil 10 is "opened", i.e. when current does not flow from the emitter to the collector. When the ignition signal input port 6 receives an ignition signal, the flow of current from the emitter to the collector occurs, thus the "primary" current flow through the primary winding 12.
As is well understood, the interruption of primary current flow through the primary winding 12 induces a secondary voltage in the secondary winding 14. Ignition is possible when the secondary voltage exceeds the breakdown voltage across the gaps 20,22, and a sufficient spark is created to ignite a mixture of fuel and air under compression. Such a spark is created at the instant the primary current flow ceases after reaching a predetermined level. FIGS. 6(a) and 6(b) show primary current flow and secondary voltage, respectively. The vertical dashed lines extending between the designated portions of FIG. 6 identify common points in time to compare and relate the different parameters.
The known ignition system, designed only to provide ignition to an internal combustion engine, is not capable of analyzing performance. For example, it is desirable to determine the state of combustion, e.g. whether combustion has or has not occurred. However, the known ignition system is not capable of determining whether an ignition signal at the input port 6 has in fact created a spark across the gaps 20,22, or whether the fuel and air mixture has actually been ignited by a spark.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an apparatus for analyzing the state of combustion in an internal combustion engine. The present invention meets this and other objectives by:
1) an ionic current computing circuit, connected via a current limiting diode and a combustion state detector to an intermediate point along the secondary winding of an ignition coil;
2) a primary flyback voltage comparator circuit, monitoring
"flyback" voltage that is developed in the primary winding at the instant the primary current is cut off;
3) a reset signal provided at a reset signal output port for the duration a spark is created across the gaps; and
4) comparing the output of the ionic current computing circuit to a reference voltage obtained through a reference voltage stabilizing circuit.
In this disclosure, ionic current refers to current flow in the secondary winding occurring as a consequence of ionization caused by combustion, when there is a voltage potential across the spark plug gaps. The ionic current computing circuit integrates the ionic current flow over time, whereupon it is possible to determine not only whether a spark was created across the gaps at the precise instant a firing signal was supplied to the firing signal input port, but also whether the fuel was actually ignited by the spark.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically shows an apparatus for detecting the state of combustion in an internal combustion engine according to an embodiment of the present invention.
FIG. 2 shows an alternate circuit diagram for the apparatus of FIG. 1 where only one spark plug gap is provided.
FIG. 3 shows a circuit diagram of a first embodiment for an ionic current computing circuit in the apparatus of FIG. 1.
FIG. 4 shows a circuit diagram of an embodiment for a primary flyback voltage comparator circuit in the apparatus of FIG. 1.
FIG. 5 shows a circuit diagram of a known system for providing ignition to an internal combustion engine.
FIG. 6 shows the relationship over time between primary current (a), secondary voltage with respect to breakdown voltage (b), ionic current with the occurrence of combustion (c), ionic current without the occurrence of combustion (d), the integrated value of ionic current with the occurrence of combustion (e), the integrated value of ionic current without the occurrence of combustion (f), the integrated value of ionic current with the occurrence of combustion (g), and the integrated value of ionic current without the occurrence of combustion (h), for the apparatus of FIG. 1.
FIG. 7 shows a circuit diagram of a second embodiment for an ionic current computing circuit in the apparatus of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Identical or similar elements of the present invention are consistently identified in the drawings and throughout the following description with the same reference number. Those elements which are identical or similar to those described in association with the known ignition system are identified by like reference numbers and are not further discussed in detail.
FIG. 1 shows an apparatus 1 for creating a spark across spark plug gaps 20,22. The spark plug gaps 20,22 are provided at opposite ends of a secondary winding 34 of an ignition coil 30. Connected at an intermediate point 36, shown here as a midpoint, of the secondary winding 34 is the cathode of a current limiting diode 38. The anode of the current limiting diode 38 is connected to a terminal 50. A supply voltage stabilizing circuit 40 maintains voltage of a motor vehicle battery to be constant within a range of 5 V and 9 V.
Whereas FIG. 1 shows two spark plug gaps 20,22, FIG. 2 shows an alternative circuit diagram with only one spark plug gap 22. The cathode of the current limiting diode 38 is now connected to the end of the secondary winding 34 opposite the spark plug gap 22, while the anode remains connected to the terminal 50. The cathode of a current leakage preventing diode 39 is also connected at the junction of the secondary winding 34 and the cathode of current limiting diode 38, and the anode of the current leakage preventing diode 39 is connected to one end of the primary winding 12.
Element 38 is shown as a diode in both FIG. 1 and FIG. 2, however, a resistor may be substituted in so far as the function of element 38 is to limit current.
FIG. 1 further shows an ionic current integrating circuit 100 connected to:
1) the terminal 50,
2) an output port 80 for providing an indication of the state of combustion,
3) a power supply 2 via a series-connected reference voltage input port 42 and supply voltage stabilizing circuit 40,
4) a collector of the ignition timing control drive transistor 4 via a series-connected reset signal output port 60 and a primary flyback voltage comparator circuit 200, and
5) the same collector of the ignition timing control device 4 via a primary flyback voltage input port 70.
FIG. 3 shows the ionic current integrating circuit 100 in detail. The ionic current integrating circuit 100 includes a series-connected capacitor 124, diode 126 and zener diode 128 provided between the terminal 50 and the ground. In particular, the anode of the diode 126 is connected to the capacitor 124, the cathode of the diode 126 is connected to the cathode of the zener diode 128, and the anode of the zener diode 128 is grounded.
FIG. 3 further shows the primary flyback voltage input port 70 is connected to the anode of a diode 130, with the cathode of the diode 130 connected to the junction between the terminal 50 and the capacitor 124. The junction between the terminal 50 and the capacitor 124 is also connected to ground via a series-connected resistor 116, zener diode 118, resistor 120 and diode 122. In particular, the cathode of the zener diode 118 is connected to the resistor 116, the anode of the zener diode 118 is connected to one end of the resistor 120, the cathode of the diode 122 is connected to the other end of the resistor 120, and the anode of the diode 122 is grounded.
The junction between the capacitor 124 and the diode 126 is connected to the junction between the zener diode 118 and the resistor 120, as well as to the cathode of a diode 114. The anode of diode 114 is connected to the non-inverting input port (+) of an operational amplifier 112. The output port of the operational amplifier 112 is connected to the output port 80 for providing an indication of the state of combustion. The connection to the inverting input port (-) of the operational amplifier 112 will be described below.
Connected in series between the reference voltage input port 42 and ground are resistors 104 and 106, as well as a capacitor 108. The junction between the resistors 104 and 106 is connected to the cathode of a zener diode 110, with the anode of the zener diode 110 connected to the inverting input port (-) of the operational amplifier 112. The junction between the output port of the operational amplifier 112 and the output port 80 also serves as the junction between the zener diode 110 and the inverting input port (-) of the operational amplifier 112. The non-inverting input port (+) of the operational amplifier 112 is also connected to the junction between the resistor 106 and the capacitor 108, as well as to the collector of a transistor 102. The emitter of the transistor 102 is grounded while the base is connected to the reset signal output port 60. The circuit diagram such as shown in FIG. 7 may be used as a second embodiment of the ionic current computing circuit 100. In the circuit diagram shown in FIG. 7, the base of the transistor 102 is connected to the reset signal output port 60, the collector of the transistor 102 is connected to the reference voltage input port 42 via the resistor 106, and the emitter of the transistor 102 is grounded via the capacitor 108. The anode of the diode 114 and the non-inverting input port (+) of the operational amplifier 112 are connected between the emitter and capacitor 108. The inverting input port (-) of the operational amplifier 112 is connected to the output port of the operational amplifier 112, and the output port connected to the output port 80. The description regarding the members from the right side of the cathode of the diode 114 shown in FIG. 7 is omitted since it is the same as FIG. 3.
FIG. 4 shows the primary flyback voltage comparator circuit 200 in detail. Series-connected resistors 210 and 212 are provided between reference voltage input port 42 and ground. The junction between the two resistors 210 and 212 is also connected via a resistor 214 to the inverting input port (-) of an operational amplifier 216, as well as to the output port of the operational amplifier 216 via a resistor 220. In turn, the junction between the output port of the operational amplifier 216 and the resistor 220 is connected to the reset signal output port 60 via a resistor 218.
FIG. 4 further shows the junction between the primary winding 12 and the ignition timing control means 4 is series-connected to the non-inverting input port (+) of the operational amplifier 216 via resistors 202 and 208. The junction between the resistors 202 and 208 is parallel-connected to ground via a resistor 204 and a capacitor 206.
The following description of the operation of the apparatus according to the present invention, with reference to the exemplary construction described above, does not discuss in detail those actions or operations that are identical or similar to those which are described in association with the known ignition system.
With regard to spark creating apparatus 1, when voltage supplied from the power supply 2 to the primary winding 12 is periodically interrupted, a corresponding high voltage is developed in the secondary winding 34 of the ignition coil 30. Immediately after a spark is created across the gaps 20,22, a predetermined voltage provided at the terminal 50 is passed through the current limiting diode 38 and a portion of the secondary winding 34, thereby producing a positive (+) voltage potential at the electrode on the coil side of each of the gaps 20,22.
It is well know that fuel is ionized during combustion, consequently, ionic current, which can be related to the state of combustion, flows across the plug gaps in the presence of the aforementioned voltage potential. Specifically, the state of combustion may be determined by monitoring the ionic current flowing from the terminal 50, through the current limiting diode 38, the secondary winding 34, a first one of the two electrodes at each of the spark plug gaps 20,22, the ionized fuel, and the second one of the two electrodes at each of the spark plug gaps 20,22, to ground. Plots against time for several parameters relevant to the present invention are shown in FIG. 6.
FIGS. 6(a) and 6(b) relate the primary current to the secondary voltage. The current flowing through the primary winding 12 reaches a predetermined level before being cut off by the ignition timing control means 4o The instant this occurs, voltage begins developing in the secondary winding 34 until it reaches the dielectric breakdown voltage, indicated as a horizontal dashed line in FIG. 6(b), thereupon creating a spark across the spark plug gaps 20,22. The terminal 50 facilitates the voltage potential at the conclusion of the spark's duration, and the ionic current flow is analyzed to determine the state of combustion based on the degree of fuel ionization.
In practice, ionic current flow is neither consistent or regular, as shown in FIGS. 6(c) and 6(d). To correctly evaluate the state of combustion, it is not sufficient to simply determine the existence of ionic current flow. The magnitude of the measured ionic current may likely to fall within anticipated upper and lower limits for ionic current, whether combustion has occurred or not.
The operation of the primary flyback voltage comparator circuit 200 and the ionic current computing circuit 100 will now be described in detail.
A primary flyback voltage comparator circuit, such as that shown in FIG. 4, uses resistors 202 and 204 to divide the flyback voltage developed (ie, when a spark at the spark plug has occurred) in the primary winding 12 at the instant the primary current is cut off. The divided voltage is input to a hysteresis comparator, such as the operational amplifier 216 supported by the peripheral circuit described above, and compared with a threshold value obtained from the reference voltage input port 42. If the divided voltage is greater than the threshold value, a reset signal is provided at the reset signal output port 60 to the ionic current computing circuit 100. The effect of the reset signal is to initialize (ground and thereby zero out) the integral value in the ionic current computing circuit 100.
In FIG. 3, when the transistor 102 is in the OFF state the charging of capacitor 108 is accomplished through stable reference voltage input port 42. When the transistor 102 is in the ON state, the capacitor 108 charging from voltage source 42 is interrupted and capacitor 108 is discharged to ground through transistor 102.
An ionic current computing circuit, such as that shown in FIG. 3, uses capacitor 108 to store electric energy supplied from the reference voltage input port 42 through resistors 104 and 106. The electrical energy stored in the capacitor is then supplied to the non-inverting input port (+) of the operational amplifier 112. The operational amplifier 112 functions as a voltage follower with a direct feedback connection from the output port to the inverting input port (-), therefore the charge voltage of capacitor 108 and the output voltage of the operational amplifier 112 eventually equalize.
The ionic current computing circuit 100 shown in FIG. 3 further shows zener diode 110 connected between the output port of operation amplifier 112 and the junction of the resistors 104 and 106. The connection of zener diode 110 ensures the voltage across the resistor 106 remains constant. Consequently, the current flowing through the resistor 106, which is equivalent to the charging current of the capacitor 108, also remains constant. Absent leakage of any current from the power supply for the operational amplifier 112 and the transistor 102, and without any current flow through the diode 114, it is possible to insure that the charge voltage of capacitor 108 increases substantially linearly. In other words, the charge voltage of capacitor 108 and the output of operational amplifier 112 will produce ramp waveforms similar to those illustrated in FIGS. 6(e) and 6(f).
In FIG. 7 showing a second embodiment of the ionic current computing circuit 100, similar to FIG. 3, the transistor 102 is in the ON state while a reset signal is output at port 60 (corresponding to the period of the gap discharging time shown in FIG. 6), and is in the OFF state except in the above-mentioned period.
When the transistor 102 is in the ON state, the input voltage from the reference voltage input port 42 is charged in the capacitor 108 via the resistor 106. The resistor 106 is adjusted to be low resistance value in such a manner that the capacitor 108 is at completely charged while the reset signal is output at port 60.
When the transistor 102 is in the OFF state, the input voltage from the input port 42 is not charged in the capacitor 108, so the capacitor 108, which was completely charged in the ON state, is discharged via the diode 114.
Therefore, when there is not an input voltage to the operational amplifier 112, current leakage from the transistor 102, nor current flown into the diode 114, the signal at the output port 80 shown in FIG. 7 will produce ramp waveforms substantially as illustrated in FIGS. 6(g) and 6(h).
The means for analyzing ionic current flow within the ionic current computing circuit 100 shown in FIG. 3 comprises capacitor 124 for storing electric energy supplied from the primary flyback voltage input port 70. Specifically, primary flyback voltage provided at the input port 70 passes through diode 130, capacitor 124, diode 126 and zener diode 128, back to ground. The zener voltage of the zener diode 128 is selected to be slightly higher than the reference voltage provided at the input port 42, thereby preventing the electric charge on the capacitor 108 from passing through diodes 114 and 126 to the ground. At the same time, the zener voltage of the zener diode 128 is selected to be lower than the primary flyback voltage provided at the input port 70, so as not to present a substantial obstacle to charging the capacitor 124.
Combustion is detected by ionic current flow through the terminal 50. According to Kirchhoff's Current Law, the magnitude of ionic current flow through the junction between capacitor 124 and diode 126 must be equal to the summation of the current components flowing into the junction between capacitor 124 and diode 126 from ground. That is to say, the summation of:
1) the ionic current flow through the capacitor 124;
2) the current flow from ground, through diode 122 and resistor 120; and
3) the current flow from ground, through capacitor 108 and diode 114, must be zero. In so far as the third of these components also has the effect of lowering the charge voltage of capacitor 108, adjustments to the third component as a result of ionic current flow (i.e. the first component) are reflected by a reduction in charge voltage of capacitor 108.
Selecting an appropriate value for the resistance for resistor 120 alters the ratio of the contribution by each of the second and third components to current flow through the junction between capacitor 124 and diode 126. This makes it possible to adjust the sensitivity of the third component to the effect of the ionic current. Therefore, according to the present invention, the magnitude of the ionic current will alter the charge voltage of capacitor 108. In case of using the ionic current computing circuit 100 shown in FIG. 3, if the ionic current is small, the output of operational amplifier 112 will increase appreciably to a higher voltage within the same unit time, whereas if the ionic current is great, the output of operational amplifier 112 is boosted only slightly within a unit time. In case of using the ionic current computing circuit 100 shown in FIG. 7, if the ionic current is small, the output of operational amplifier 112, as shown in FIG 6(h) attenuated within a unit time less than when the ionic current is great and the output of the operational amplifier 112, is attenuated appreciably more, as shown in FIG. 6(g). The output of the operational amplifier 112 is supplied to the output port 80, and is compared (by a known, per se, I.C. engine ECU) with predetermined limit value(s) (upper, lower or both) so as to determine the state of combustion.
Rather than attempting to determine the state of combustion by measuring an instantaneous value of ionic current, the apparatus according to the present invention computes the quality of ionic current. The advantage being the positive determination of not only whether a spark is created across the gaps at the instant a firing signal is supplied to the firing signal input port, but also whether the fuel has actually been ignited.
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An apparatus for determining the ignition characteristic of combustion in an internal combustion engine having an ignition coil including an ionic current computing circuit which analyzes ionic current enabled as a result of combustion. Ionic current flow is facilitated by establishing a voltage potential across the gap of a spark plug the instant after an ignition spark across the gap has occurred. The flow of ionic current enabled by the combustion process is provided to an ionic current computing circuit effecting the creation of a signal reflecting the flow of ionic current. The output signal from the computing circuit is integrated to determine the quality (length and magnitude of ionic current flow. This quality of flow is compared against predetermined high and low values for the integrated value and the ignition characteristic or state of combustion, ie, whether a spark and/or complete combustion has occurred, of the cylinder can be understood.
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The present invention relates to a method in accordance with the preamble of claim 1 for the generation of real-time control parameters by means of a video camera signal for the control of smoke-generating combustion processes.
DESCRIPTION OF THE BACKGROUND ART
In stoker boilers the combustion process is controlled by means of a direct camera-to-monitor chain. A black-and-white video camera, especially developed for the monitoring of combustion processes, is mounted in the wall of the fire box. A special construction video camera for this application is often called a fire-box monitoring camera. The unprocessed video output signal from the video camera is connected to a monitor. Then, based on the video image, the required control procedures of the stoker boiler, such as the control of a hydraulically driven stoker or quantity of combustion air, are effected. The goal of video signal use has been to define from the video image the location of the flame front which is the principal control parameter, as well as to locate possible craters in the fuel bed which cause an uneven air flow.
In soda recovery boilers the combustion process is monitored by means of a video camera but principal information is obtained via the air feed openings.
A disadvantage of the prior art technique is that the image obtained by using the direct video connection is rather undefined due to the random movement of the flames. Also, the generation of smoke disturbs the image. Consequently, the control information obtained from the video image is mostly approximative and does not provide means for an efficient control of the combustion process. In soda recovery boilers the video image gives relatively little information because most of the radiation emitted by the combustion process does not effectively fall within the range of visible light. Monitoring the process via the air feed openings is awkward and leaves obscured areas in the visible field.
SUMMARY OF THE INVENTION
The present invention aims to overcome the disadvantages of the aforementioned technique and to achieve a completely novel method for generating real-time control parameters by means of a video camera for smoke-generating combustion reactions.
The invention is based on monitoring the combustion process with a video camera whose signal is digitized, filtered appropriately, and formatted on the basis of the distribution of the digitized signal, into a histogram table for image processing in which the table is processed into an image from which the location of the flame front is appropriately identified for process control on the basis of the averaging of video images.
More specifically, the method in accordance with the invention is characterized by a method for generating real-time control parameters by means of a video camera for smoke-generating combustion processes with the method based on generating a video signal by means of a video camera, digitizing the video signal, and filtering the digitized video signal temporally and spatially, characterized by the following, dividing the digitized video signal on the basis of its signal level distribution onto signal subareas in order to reduce the quantity of information to be handled, combining the picture elements belonging to the same subarea into contiguous image areas, each of which corresponds to a certain signal level, combining the subareas into an integrated image, averaging the subsequent images so as to eliminate the effect of random disturbances, and displaying the averaged image on a display device.
The invention provides appreciable benefits.
In its practical implementation, the method in accordance with the invention provides an image in the form of a two-dimensional table indicating the short-term average value of the temperature distribution of the fuel bed, which facilitates the easy localization of the flame front location, size, and form, from the image. Because of the fast computation method, the image processing takes only a few seconds, which allows a real-time control of the combustion process. Images obtained by use of the method can be compared to an optimum condition, which simplifies the control task. A time related comparison of subsequent averaged images make it possible to anticipate the spreading of the flame front and to estimate the stability of the combustion process.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, the present invention will be examined in detail by means of exemplifying embodiments illustrated in the enclosed drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 shows a longitudinal partially cross-sectioned perspective view of a stoker boiler with a fire-box monitoring camera installed therein;
FIG. 2 shows a partially cross-sectioned perspective view of the stoker construction of a stoker boiler;
FIG. 3 schematically shows conventional monitoring equipment for the combustion process;
FIG. 4 schematically shows monitoring equipment for the combustion process in accordance with the present invention;
FIG. 5 schematically shows a block diagram of the method in accordance with the present invention;
FIG. 6 shows a histogram of the fire-box monitoring camera image when the combustion process is unobstructedly visible;
FIG. 7 shows a histogram of the fire-box monitoring camera image when the combustion process is obscured by smoke or steam;
FIG. 8 shows a top view of a stoker with combustion zones and a combustion zone model formed thereof; and
FIG. 9 shows a display screen format compliant with the method in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows the combustion process of a stroker boiler 15 operating very close to the optimum. A fuel bed 13 is burning with a continuous firing front 14 at the lower end of a boiler stoker 16. Omitted from FIG. 1 are the undesirable craters which may be created in the fuel bed 13 if firing occurs elsewhere other than at the lower end of the bed. As shown in FIG. 2, the craters cause an airflow 17 which enters from below through the stoker, with the flow concentrating in the craters, thus inhibiting the controlled combustion air flow through the fuel bed 13 and further causing an uneven humidity profile percentage in the fuel bed 13.
FIG. 4 shows in a simplified form the combustion process monitoring members and their interconnections associated with the method in accordance with the present invention. A fire-box monitoring camera 12 provides a video output signal to an image processing unit 18, which is connected to a color monitor 19 and an automation system 20 of the stroker boiler 15. Furthermore, the automation system 20 is connected via a control line to the control system of the boiler 15 and the color monitor 19.
FIG. 5 shows in detail the main principles of the method in accordance with the present invention. The first block represents the fire-box monitoring camera 12 from which the video signal is routed, to the second block in which the digitization of the image is performed by quantization of the analog video signal to discrete levels; transferred to an image memory, and finally, information is read from the image memory into the working memory of the computer with an appropriate reduction of image information. Information can be compacted by omitting every other picture element and every other scan line without losing the efficiency of the method. In the applied method, this means a reduction of resolution from 256×256 pixels to 128×128 pixels. The second block also performs a filtering operation in which the comparison of subsequent picture elements is used for reducing large intensity differentials between subsequent picture elements, and a temporal filtering operation in which the value of each picture element signal is compared to the temporally preceding value of the same picture element, after which computational methods are applied to reduce large variations in order to attenuate large signal variations caused by sparking and smoke. The third block performs image averaging with contrast reduction of the image signal. This kind of image "make up" can be used for reducing disturbance. In the fourth block, the "made up" information is used for numerically searching for the desired pixel values by means of histogram processing (to be described later) so as to find the picture elements characteristic of combustion areas 1, 2 in this embodiment. Block five performs the image analysis in which the image is compared to previous images and the optimum situation, after which the control operations are performed by block six. Block seven assigns each intensity level an individual color to be displayed in the color monitor 19 of block eight, which serves as the real-time supervisory monitor for the boiler plant operator.
After the video signal has been digitized, filtered and processed in the foregoing manner, areas corresponding to an effective combustion are defined using histograms shown in FIGS. 6 and 7. The definition of intensity levels on the basis of histograms may be performed irregularly for calibration purposes: in practice, however, it has proven necessary to define the intensity levels at regular intervals, for instance, at five minute intervals. The horizontal axis of FIG. 6 illustrates the intensity levels of picture element signals from the camera, which may receive 63 discrete values so that the intensity is increased from the left to the right in the diagram. The vertical axis shows the percentage distribution of picture elements at each intensity level in relationship to the total number of picture elements.
Compressed and averaged on the basis of the histogram, the image is quantized to intensity levels essential to the combustion process. A picture element is assigned to a certain intensity level if its intensity value is equal to or larger than the lower limit defined for the level and smaller than or equal to the upper level defined for the level. The quantization result is shown by means of a bar table in which the points belonging to the same intensity level, and located adjacently in the same row, form a bar. Normally, the bar table is shown on a CRT monitor screen where a horizontal row is represented by a horizontal bar formed from the picture primitives of the CRT display. The bar display format offers an essential reduction of processed information.
On the basis of the bar table, the contiguous areas of the flame image are identified. In this context, a contiguous area is defined as an area having the intensity values of its adjacent picture elements belonging to the same quantization level of intensity and having a closed contour. A contiguous area may also incorporate holes or voids, which are not belonging to the aforementioned intensity level.
FIGS. 6 and 7 illustrate the method in detail. Shown in FIG. 6 is a histogram in which the whole of the firing front 14 is unobscuredly visible. The unobscured combustion is represented in FIG. 6 by such picture elements whose intensity value is larger than an intensity value 21 corresponding to a minimum value 20 of the histogram. In accordance with FIG. 7, combustion zones obscured by smoke or steam are represented by such picture elements whose intensity value is larger than an intensity value 22 or smaller than an intensity value 23 in FIG. 6. The intensity value 22 is defined as an intensity value whose derivative of picture elements in respect to the intensity is largest and which is located to the right from the inflection point located to the right from the peak 23 in FIG. 6. Combustion zones 1 are represented by such contiguous areas which fulfill the aforementioned criteria and are defined and identified by means of their area, point of gravity coordinates of the area, and point-by-point recorded contours of the area. In addition, any possible areas, gravity points and contours of voids inside the area are defined.
In FIG. 8, which especially illustrates the combustion zone 1 of a stoker boiler, the fuel transport direction is indicated by an arrow 26, while the combustion zone 1 and its location are defined as follows:
the image is divided into columns in the transport direction of the fuel, with one of the columns shown in the left part of FIG. 8,
the areas and point-of-gravity coordinates obtained for these areas are computed for two intensity level classes of the combustion zones 1, 2 defined above so that,
the combustion zone proper is an area found in the column and representing either of the combustion zones by virtue of having a width equal to the column width and a shape corresponding to its actual area, and having the form of a rectangle, which is symmetrically located in respect to its gravity point 25, parallel to the direction of the column.
Effective combustion on the time scale is represented by the median area, computed from the areas of combustion zones identified in subsequent images over a time span of 1 . . . 2 minutes. The movement velocity and direction of the combustion zones is defined from the slope of the regression line computed from temporally subsequent values of gravity points that correspond to the median areas. The stability of combustion is represented by the ratio of the standard deviation of areas to the average values of areas in a series of areas determined from the subsequent images. A low value of oscillation indicates a stable and good combustion process while a large value of oscillation is characteristic of disturbances in combustion. The ratio of combustion indicating areas to the total area correlates with the quality of fuel.
FIG. 9 shows a method for formatting the characterizing variables of combustion described above in order to display them on a CRT monitor, which is used as a display device in the method according to the invention. Areas 1 are representative of the area of the hottest zone within the column and, consequently, the combustion zone. The gravity point of the zone is located vertically in the mid of the zone. Areas 2 illustrate the combustion zones of the lower intensity level. An area 9 illustrates the fuel zone. An area 6 illustrates a combustion zone external to the actual flame front 14. The edge of the fuel bed has been stopped at a point 7, where firing was latest observed. Bars 3 indicate the extrapolated location of gravity points of combustion areas after a few minutes. A white area 10 represents ash.
The hereinbefore described method can also be applied to soda recovery. The method is excellently applicable to the temperature control of a soda recovery boiler because the temperature differentials involved are in the same order of magnitude. In the soda recovery boiler, the camera can be located in, for instance, a primary or secondary air inlet opening, thus facilitating the monitoring of the soda bed shape. Due to the wavelengths present in a soda recovery boiler, the use of an IR sensitive camera is preferred.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
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A method for generating real-time control parameters by a video camera for smoke-generating combustion reactions is disclosed. In accordance with the method, a video camera is used for obtaining a video signal, which is digitized and filtered temporally and spatially. The digitized video signal is divided on the basis of its signal level distribution into signal subareas to reduce the quantity of processed information. The picture elements belonging to the same subarea are combined into contiguous image areas representing a certain signal level, the subareas are combined into an integrated image, subsequent images are averaged to eliminate random disturbance, and the averaged image is displayed on a display device. This method facilitates the real-time monitoring of a combustion process.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Patent Provisional Application No. 60/204,413, filed on May 16, 2000.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
(Not Applicable)
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to drainage systems located on the bottom or along the side of a swimming pool or spa. More particularly, the invention relates to a method and apparatus for preventing the entrapment of a person in the drain of a swimming pool or spa.
2. Description of the Related Art
Swimming pools and spas typically have systems for draining and recirculating water. Such systems usually have a main drain or sump located at or near the bottom of the swimming pool or spa. Water is normally suctioned out of the swimming pool or spa through the main drain, into an inlet of a suction pump, and then drained or recirculated back into the swimming pool or spa through jets located around the interior wall of the swimming pool or spa.
When bathers place their heads or bodies in the vicinity of an active drain, their hair or a portion of their body may become entrapped in a portion of the drain, such as a cover or grating. A sealed drain can develop a strong vacuum within a few seconds. If the vacuum pressure is strong enough, a bather who is entrapped by a drain may not be able to break free of the vacuum and may ultimately drown.
Swimming pool and spa safety organizations, such as the United States Consumer Product Safety Commission (CPSC), the National Spa and Pool Institute (NPSI), and various state government entities, have acknowledged the need for devices that protect against swimming pool and spa drain entrapment. Of particular concern are entrapments involving hair entanglement, limb entrapment, body entrapment, and disembowelment. Hair entanglement occurs when a bather dips below a water surface and his or her hair is sucked into and becomes entangled on a drain grate on the main drain of a swimming pool or spa. Body entrapment typically occurs when part of a bather's torso completely covers an unprotected or damaged drain, thereby creating a vacuum within the drain from which the bather cannot break free. Limb entrapment refers to accidents in which a bather's arm or leg is sucked into a main drain of a swimming pool or spa. Disembowelment accidents occur where small children, usually three to six years old, sit on a drain. Injury occurs when their lower intestines are sucked out of their body through their anus.
Various devices have been used to prevent entrapment. For example, swimming pools and spa have been provided with multiple drains, as opposed to just a single drain, to prevent a vacuum from being formed when one of the drains is obstructed. A system with multiple drains has its drawbacks, however, in that it can be significantly more expensive. Additionally, multiple bathers can cover the multiple drains, permitting the creation of the hazardous vacuum which the system is designed to prevent.
Pressure detection systems have also been used to reduce the risk of entrapment. Pressure detection systems shut off a drain system when the vacuum pressure within the system reaches a critical level. Unfortunately, the complexity of such systems raises reliability concerns. Thus, a need still exists for an improved method and apparatus for preventing entrapment.
SUMMARY OF THE INVENTION
One aspect of the present invention relates to a pool drain safety cover. The cover includes a base defining at least one primary fluid aperture and a plurality of secondary fluid apertures. The cover also includes a grating extending across at least the primary fluid aperture for permitting the passage of drain water therethrough. The grating has at least an upper layer and a lower layer. The upper and lower layers are adjacent, and each is comprised of a plurality of spaced ribs for permitting the passage of fluid in a clearance space between the ribs.
Another aspect of the invention relates to a method for providing a pool drain safety cover. The method includes providing a base defining at least one primary fluid aperture and a plurality of secondary fluid apertures. The method also includes positioning across at least the primary fluid aperture a grating for permitting the passage of drain water therethrough. The grating includes at least an upper layer and a lower layer. The upper and lower layers are adjacent, and each includes a plurality of spaced ribs for permitting the passage of fluid in a clearance space between the ribs.
According to either aspect of the invention, the ribs of the upper layer can be perpendicular to the ribs of the lower layer. The spacing between the ribs can be between approximately one-eighth inch and one-sixteenth inch. The base can include a perimeter portion surrounding the primary fluid aperture, and a plurality of protrusions extending from an underside of the perimeter portion. Adjacent pairs of the plurality of protrusions can define the secondary fluid apertures. A tip portion of the protrusions can extend radially beyond the perimeter portion. The tip portion can have a smoothly contoured curved face.
BRIEF DESCRIPTION OF THE DRAWINGS
There are presently shown in the drawings embodiments which are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
FIG. 1 is a perspective view of a drain safety cover according to the invention.
FIG. 2 is a top view of the cover of FIG. 1 .
FIG. 3 is an enlarged cross-sectional view of the cover of FIG. 1, taken along the line 3 — 3 in FIG. 2 .
FIG. 4 is a perspective view of a base of FIG. 1 .
FIG. 5 is a bottom view of the cover of FIG. 1 .
FIG. 6 is an enlarged cross-sectional view of a portion of a protrusion attached to the base of FIG. 2, taken along line 6 — 6 in FIG. 2 .
FIG. 7 shows the cover of FIG. 1 positioned over a drain.
FIG. 8 is a cross-sectional view of the cover of FIG. 1 attached to a drain.
FIG. 9 is a cross-sectional view of the cover of FIG. 1 positioned over a drain, illustrating how fluid can flow through the cover prior to entering the drain.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a drain safety cover 10 according to the present invention. The cover 10 can be positioned over a pool drain to prevent bathers from being trapped by the suction of the drain. The cover 10 includes a grating 12 . The cover 10 can also include a base 14 for receiving the grating 12 .
The grating can have a top portion 18 and a side portion 20 . As shown in FIG. 2, the top portion 18 can have at least one upper layer of spaced ribs 24 and at least one lower layer of spaced ribs 26 . The ribs within the upper layer 24 and lower layer 26 can extend partially or completely across the top portion 18 . The upper layer 24 and the lower layer 26 are preferably adjacent to each other, as shown in FIG. 3 . The upper layer 24 and the lower layer 26 define a clearance space 22 through which fluid can pass.
As shown in FIG. 3, the ribs in the upper layer 24 are preferably substantially parallel to each other. The ribs in the lower layer 26 are also preferably substantially parallel to each other. In addition, the ribs in the upper layer 24 are preferably substantially perpendicular to the ribs in the lower layer 26 . It should be understood that the invention is not limited to these particular orientations, however, as any suitable angles of orientation are acceptable.
Referring again to FIG. 1, the side portion 20 of the grating 12 can include at least one upper layer of one or more ribs 28 , and at least one lower layer of one or more ribs 29 . The upper layer 28 and the lower layer of 29 can be adjacent to each other, and the upper layer 28 and the lower layer 29 can each have clearance space 22 through which fluid can pass. The ribs in the upper and lower layers 28 , 29 of the side portion 20 can extend partially or completely across the side portion 20 . The ribs in the upper and lower layers 28 , 29 of the side portion 20 can be oriented in the same manner as the ribs in the upper and lower layers 24 , 26 of the top portion 18 . Thus, the ribs in the upper layer 28 can be substantially parallel to each other, the ribs in the lower layer 29 can be preferably substantially parallel to each other, and the ribs in the upper layer 28 can be substantially perpendicular to the ribs in the lower layer 29 . It is understood that the invention is not limited to these parallel and perpendicular orientations, however, as any other suitable angles of orientation are also acceptable.
Positioning the upper and lower layers of the top portion 18 and/or the upper and lower layers of the side portion 20 in the orientations described above has been found to provide distinct advantages over the prior art. Specifically, hair which is placed in the vicinity of the grating 12 can be substantially or entirely prevented from entering the clearance space 22 . Consequently, such a design can prevent hair entanglements and thereby protect individuals from being trapped by the suction of a drain covered by the cover 10 . Notably, however, a cover 10 in accordance with the inventive arrangements will not significantly interfere with the flow of fluid through the cover 10 .
In one arrangement, the ribs in the upper and lower layers 24 , 26 of the top portion 18 and the ribs in the upper and lower layers 28 , 29 of the side portion 20 can be spaced approximately one-sixteenth inch apart, approximately one-eighth inch apart, or between approximately one-eighth inch and approximately one-sixteenth inch apart. It should be noted, however, that the invention is not limited to these particular dimensions, as other suitable dimensions are also acceptable.
In addition, the top portion 18 of the grating 12 can have a plate 30 . In one arrangement, the plate 30 can be a section of the top portion 18 , and can be substantially centrally located on the top portion 18 . Further, the plate 30 can have a perimeter that is less than the perimeter of the top portion 18 so as not to substantially interfere with the flow of fluid through the grating 12 . Including a plate 30 with the grating 12 can provide extra support to the grating 12 , as the plate 30 can provide a solid surface over a portion of the grating 12 .
In another arrangement, any layer of the grating 12 can include one or more ribs 31 having a thickness greater than the remaining ribs, where the greater thickness reduces the spacing between the ribs within the layer. Including one or more thicker ribs 31 in one or more of the layers of the grating 12 can provide extra support to the cover 10 , and can help the cover 10 absorb collisions or impacts. Although FIG. 1 shows the grating 12 as having two thicker ribs 31 , it should be noted that the invention is not limited to this particular arrangement.
As previously indicated, the invention can also include a base 14 . FIG. 4 shows an example of a suitable base 14 . Although FIG. 4 shows the base 14 as having a circular shape, the invention is not so limited, as the base 14 can be any other suitable shape capable of receiving the grating 12 and covering a drain. The base 14 can have a perimeter portion such as a ring 32 , which can enlarge the size of the cover 10 and possibly further reduce the risk of entrapment or injury. The ring 32 can define a primary fluid aperture 34 through which fluid can flow from the grating 12 to a drain.
The base 14 can have one or more support members 36 extending partially or completely across the primary fluid aperture 34 upon which the grating 12 can be seated. Alternatively, one or more projections (not shown) placed along an inner perimeter 38 of the primary fluid aperture 34 can be used to support the grating 12 .
For purposes of holding the grating 12 in place, the perimeter of the side portion 20 of the grating 12 can be substantially equivalent to the inner perimeter 38 of the primary fluid aperture 34 of the base 14 . Such an arrangement can provide a snug fit between the grating 12 and the base 14 . The invention, however, is not limited to this particular arrangement, as any other suitable structure or process can be used to secure the grating 12 to the base 14 . For example, the grating 12 and the base 14 can be constructed as one component in which the grating 12 can be secured to the base 14 during the manufacturing process.
Referring to FIG. 5, the base 14 can have one or more protrusions 40 which can be arranged radially about the underside of a perimeter portion such as a ring 32 . The protrusions 40 can define a plurality of radially spaced secondary fluid apertures 41 beneath the ring 32 for ensuring an unimpeded fluid flow path in the event that an obstruction is placed over the grating 12 . In one arrangement, most of the protrusions 40 do not extend beyond the inner perimeter 38 of the primary fluid aperture 34 of the base 14 so as not to interfere with the fluid flowing through the grating 12 . One or more of the protrusions 40 , however, can be extended across the primary fluid aperture 34 , for example to form the support members 36 for supporting the grating 12 .
The ends of one or more of the protrusions 40 can be rounded or tapered. The invention, however, is not so limited, as the protrusions 40 can be any suitable shape. FIG. 6 shows a suitable protrusion 40 , in which a top surface 42 of the protrusion 40 can be tapered such that the top surface 42 slopes substantially downwards towards an end 44 of the protrusion 40 . In addition, the top surface 42 and the end 44 can be rounded. The upper layers 26 of the grating 12 can be positioned above, below, or at the same level as the uppermost surface of the ring 32 . In one arrangement (not shown), a section of the side portion 20 of the grating 12 can extend below the underside of the ring 32 SO that fluid flowing through secondary fluid apertures 41 can also pass through the side portion 20 .
FIG. 7 shows the cover 10 attached to a drain 16 . The cover 10 may be attached to a drain 16 in any suitable manner. For example, a portion of the cover 10 may be mounted to the drain 16 with any suitable mechanical or chemical fastening structure, such as screws, bolts, nails, or adhesive. To receive such a suitable fastening structure, one or more holes 46 can be provided in the ring 32 of the base 14 , as shown in FIG. 4 . Although FIG. 4 shows the base 14 as containing eight holes 46 , the invention is not limited to this particular embodiment, as the base can contain any suitable number of holes 46 . As shown in FIG. 5, the holes 46 can be positioned on the base 14 such that the holes 46 pass through one or more protrusions 40 . Such an arrangement can provide extra support to the base 14 , as a greater portion of the base 14 can be engaged by the suitable fastening structure inserted into the holes 46 . Notably, however, the invention is not limited in this regard, as the holes 46 can be located at any other suitable location on the base 14 . FIG. 8 shows one or more fasteners 48 being inserted into the holes 46 to secure the cover 10 to the drain 16 .
FIG. 9 shows the path of fluid through the grating 12 and the base 14 . Fluid can enter the top portion 18 of the grating and can pass through the upper layers 26 of the grating (not shown) before entering the drain 16 . Further, fluid can enter and pass through the side portion 20 of the grating 12 before entering the drain 16 . Fluid can also pass through the secondary fluid apertures 41 formed by the protrusions 40 and, if so desired, can pass through a section of the side portion 20 before the fluid enters the drain 16 . The arrangement illustrated in FIG. 9 can prevent a bather from being trapped by the low pressure area created by the drain 16 , yet does not significantly interfere with the flow of fluid through the grating 12 and the base 14 .
It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be obvious to persons skilled in the art, and that such modifications or changes are to be included within the spirit and purview of this application. Moreover, the invention can take other specific forms without departing from the spirit or essential attributes thereof.
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A pool drain safety cover system and method. The system includes a base defining at least one primary fluid aperture and a plurality of secondary fluid apertures. The cover also includes a grating extending across at least the primary fluid aperture for permitting the passage of drain water therethrough. The grating has at least an upper and a lower layer. The upper and lower layers are adjacent, and each is comprised of a plurality of spaced ribs for permitting the passage of fluid in a clearance space between the ribs.
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BACKGROUND OF THE DISCLOSURE
[0001] 1. Field of the Disclosure
[0002] The present disclosure relates to flexible composite pipe for conducting petroleum or other fluids offshore or on land and a method of controlling gaps within the same.
[0003] 2. Description of the Related Art
[0004] A composite flexible pipe may be formed, in part, from composite tape stacks of laminated tape strips. The composite tape stacks may be helically wound onto a pipe to provide structure and support. Gaps may form between adjacent wrappings of the tape stacks, which may allow for blow through of a fluid barrier or layer that may be beneath the wrappings. However, advantageously, the gaps may provide flexibility to the wrapped layers so that there may be relative movement or spacing between adjacent layers, thereby allowing the pipe to bend and/or flex. Therefore, control over the gaps may be desired so as to prevent blow through of a fluid barrier, but allow flexibility in the pipe.
[0005] In traditional steel pipes, which may be flexible pipes, interlocking layers or wrappings may be employed to control the blow through and provide gap control. This is particularly prevalent in high-pressure applications, where pressure armor may be employed to provide resistance to internal and external pressure and mechanical crushing loads. The pressure armor may include interlocked metallic hoop strength layers and gaps may be controlled by only allowing a maximum separation between adjacent wraps to be the full extension of interlocked wraps. Furthermore, an internal pressure sheath material may be able to span the gap under a high internal pressure loading, thereby allowing some flexibility to the pipe, but also preventing blow through of the internal pressure sheath.
[0006] However, in the design of some flexible pipes, which may employ composite materials for reinforcement layers, and, particularly, flexible fiber reinforced pipe, there may be no interlocking layers. As such, gap control may be difficult to achieve effectively.
SUMMARY OF INVENTION
[0007] In one aspect, the present disclosure relates to a tubular assembly with gap control. Embodiments disclosed herein relate to one or more embodiments of and methods for controlling gaps between helically wrapped layers in a pipe structure. A tubular assembly includes a fluid barrier, a first layer, and a second layer comprising a plurality of non-interlocking helical wraps and disposed on an outer surface of the first layer, in which the first layer is disposed between the fluid barrier and the second layer and configured to at least partially displace into a space created between adjacent non-interlocking helical wraps of the second layer. The helically wrapped layers may include composite tape stacks.
[0008] In another aspect, the present disclosure relates to a method to control gaps between adjacent non-interlocking helical wraps disposed on a tubular member. The method includes installing a control layer between a curved outer surface of the tubular member and the non-interlocking helical wraps, in which the control layer is configured to at least partially displace between the adjacent non-interlocking helical wraps from underneath the wraps.
BRIEF DESCRIPTION OF DRAWINGS
[0009] Features of the present disclosure will become more apparent from the following description in conjunction with the accompanying drawings.
[0010] FIG. 1 shows an isometric view of a composite flexible pipe in accordance with one or more embodiments of the present disclosure.
[0011] FIG. 2 is a cross-sectional view of a composite flexible pipe in accordance with one or more embodiments of the present disclosure.
[0012] FIG. 3 is a cross-sectional view of a composite flexible pipe in accordance with one or more embodiments of the present disclosure.
[0013] FIG. 4A is a top view, FIG. 4B is a cross-sectional view, and FIG. 4C is a blown up cross-sectional view of a gap control layer in accordance with one or more embodiments of the present disclosure.
[0014] FIG. 5 is a cross-section view of a portion of a composite flexible pipe in accordance with one or more embodiments of the present disclosure.
[0015] FIG. 6 is a cross-section view of a portion of a composite flexible pipe in accordance with one or more embodiments of the present disclosure.
DETAILED DESCRIPTION
[0016] A control layer and method of controlling gaps of a non-interlocking helically wrapped layer of a flexible pipe in accordance with one or more embodiments will be described herein with reference to the accompanying drawings.
[0017] Referring to FIG. 1 , an isometric view of a composite fiber reinforced flexible pipe 100 is shown. A fluid barrier (or liner or internal pressure sheath) 102 may be wrapped with a hoop reinforcement layer 104 , tensile layers 106 and 108 , and may be sealed, covered, and/or protected by a jacket (or outer sheath) 110 . Further, an anti-extrusion layer may be included between the fluid barrier 102 and the hoop reinforcement layer 104 . The anti-extrusion layer may include multiple layers and/or wrappings 120 and 122 of an anti-extrusion material, such as fiber reinforced tape, polymers, and/or any other pressure resistant material known in the art. Further, those skilled in the art will appreciate that composite flexible pipe 100 may be made of different and/or additional layers including perforated cores, collapse resistant hoop layers, anti-wear layers, lubricating layers, tensile layers, membranes, burst resistant hoop layers, perforated jackets, and/or any other additional layers, or combinations thereof, without deviating from the scope of the present disclosure.
[0018] In certain embodiments, hoop reinforcement layer 104 may be made from laminated tape stacks such as that disclosed in U.S. Pat. No. 6,491,779, filed on Apr. 24, 2000, entitled “Method of Forming a Composite Tubular Assembly,” U.S. Pat. No. 6,804,942, filed on Sep. 27, 2002, entitled “Composite Tubular Assembly and Method of Forming Same,” U.S. Pat. No. 7,254,933, filed on May 6, 2005, entitled “Anti-collapse System and Method of Manufacture,” and U.S. Patent Application Publication No. 2008/0145583, filed on Dec. 18, 2006, entitled “Free Venting Pipe and Method of Manufacture,” all of which are hereby incorporated by reference in their entireties.
[0019] Hoop reinforcement layer 104 may be wound at any “lay angle” relative to the longitudinal axis of fluid barrier 102 , in which higher lay angles may provide relatively high hoop strength and lower lay angles may provide relatively high axial strength. However, in accordance with one or more embodiments of the present disclosure, hoop reinforcement layer 104 may be wound at a relatively high lay angle relative to the longitudinal axis of the pipe, for example 60° to 89°, to provide internal pressure resistance against burst and/or external pressure resistance against collapse or crushing due to external loads. As noted, hoop reinforcement layer 104 may be made from stacks of tape, which may include fibers of glass fiber, aramid, carbon, and/or any other fiber used in composite structural materials.
[0020] Further, those skilled in the art will appreciate that the hoop reinforcement layer 104 may be made from steel wire which may be helically wound at a high lay angle to provide hoop strength. The steel wire may be rectangular or any other shape that may allow for a high lay angle. Additionally, although only one hoop strength layer 104 is shown in FIG. 2 , those skilled in the art will appreciate that multiple layers or wrappings of hoop reinforcement to provide additional burst, collapse, or crushing resistance may be applied to a pipe without deviating from the scope of the present disclosure. Furthermore, superimposed hoop strength layers may be counter-wound, such that, for example, one layer may be wound clockwise and a next layer may be wound counter-clockwise, so as to provide and/or improve torsion balance within the pipe.
[0021] Hoop reinforcement layers 104 may have gaps 128 formed between adjacent wrappings of the layer. Gap 128 may result from imperfect installation, particularly if 100% coverage of a liner or other previously applied layer is desired and/or attempted to be achieved. Alternatively, gaps 128 may be intentionally produced, so as to allow for flexibility within pipe 100 .
[0022] Further, as shown in FIG. 1 , anti-extrusion layers 120 and 122 may be applied to a pipe structure to prevent fluid barrier 102 from entering gaps 128 and to prevent blow-through of fluid barrier 102 . Multiple layers may be applied so that stronger blow through resistance is achieved. As the blow through resistance (i.e., layers 120 and 122 , and any additional layers) is increased, gap 128 may be increased in size, thereby allowing more flexibility. However, a larger gap 128 may increase the likelihood of blow-through of fluid barrier 102 .
[0023] Further, although only two anti-extrusion layers between fluid barrier 102 and hoop reinforcement layer 104 are shown in FIG. 1 , those skilled in the art will appreciate alternative structures may be used without deviating from the scope of the present disclosure. For example, additional anti-extrusion layers, in accordance with one or more embodiments of the present disclosure, or other anti-extrusion layers and/or lubricating layers, may be applied between two hoop strength layers and/or between any superimposed, adjacent, and/or sequentially wrapped layers. For example, an anti-extrusion layer such as that disclosed in U.S. Patent Application Publication No. 2008/0145583 may be applied, or a lubricating layer and/or anti-wear layer described in American Petroleum Institute Specifications 17J and 17B, which are hereby incorporated in their entireties, may be applied. Further, more than one layer may be wrapped and/or applied between consecutive pipe structure layers, thereby providing a stronger anti-extrusion layer.
[0024] During the manufacture and operation of pipe 100 , control of gaps 128 between adjacent wrappings of a helically wrapped layer may be desired. Gaps 128 may allow for appropriate spacing between adjacent wrappings so that the pipe may flex and/or bend, without damaging the pipe structure. As noted above, a composite flexible pipe may be made without interlocking adjacent wraps, and therefore an alternative gap control system and/or method may be necessary.
[0025] Referring again to FIG. 1 , anti-extrusion layers 120 and 122 may provide gap control. A first layer 120 may be helically wrapped around fluid barrier 102 . A second layer 122 may be helically wrapped around the first layer 120 , but second layer 122 may be wrapped with an offset from first layer 120 , such that the gaps between adjacent wraps of first layer 120 may be covered by second layer 122 . Further, second layer 122 may, at least partially, be made of a material that may allow for at least part of second layer 122 to displace between adjacent wraps of hoop layer 104 which may be wrapped over second layer 122 .
[0026] The displaced material of second layer 122 may form a filler 124 , which may be displaced bedding material (as described below). As shown in FIG. 1 , filler 124 may fill gaps 128 that form between adjacent wrappings of hoop layer 104 . Accordingly, filler 124 may form as a counter-wound raised surface of second layer 122 , as shown in FIG. 1 . Filler 124 may provide gap control between the wrappings of hoop layer 104 .
[0027] As shown in FIG. 1 , the first and second anti-extrusion layers 120 and 122 may be made of rectangular cross section tape that may be helically wound around fluid barrier 102 . Anti-extrusion layers 120 and 122 may be reinforced with uniaxial or woven fibers that may provide tensile and/or lateral strength and may be twisted and/or woven (see FIGS. 4A-4C ). Furthermore, cross fibers may be woven perpendicular to the uniaxial fibers to provide additional strength and/or support.
[0028] The reinforcement fibers of anti-extrusion layers 120 and 122 may be made from glass fiber, aramid, carbon, metallic fibers, and/or any other fibrous materials known in the art. The reinforcement fibers may be short fibers or long chopped fibers embedded in a polymer matrix, so as to provide appropriate reinforcement to the anti-extrusion layers.
[0029] Moreover, although shown as two wrappings of a tape, anti-extrusion layers 120 and 122 may be a single anti-extrusion layer, such as a single tape wrapping, a sleeve, or an extruded layer or may be more than two wrappings, sleeves, and/or layers or combinations thereof without deviating from the scope of the present disclosure.
[0030] Furthermore, second layer 122 may include a low modulus bedding material, allowing for a low stress concentration in second layer 122 at the edge of gaps 128 in hoop layer 104 . Fillers 124 of anti-extrusion layer 122 may form because of the bedding material, and/or bedding layer, of anti-extrusion layer 122 . The bedding material may be a polymeric material, and, more particularly, may be an elastomeric material, for example, elastomers and other materials used in bonded flexible pipe. Furthermore, the bedding material, used to form the fillers, may include a foam material to allow for greater displacement and/or expansion.
[0031] Alternatively, in accordance with one or more embodiments of the present disclosure the elastomeric material, which may cover any reinforcement fibers, may be made of a swellable material, such as that disclosed in U.S. Patent Application Publication No. 2008/0093086, filed on Oct. 19, 2007, entitled “Swellable Packer Construction for Continuous or Segmented Tubing,” which is hereby incorporated by reference in its entirety. The swellable material may swell in the presence of water or other moisture, thereby expanding and displacing between adjacent wraps in layer 104 and forming fillers 124 . During manufacture, after a swellable anti-extrusion layer may be applied, and a hoop layer may be wrapped over the anti-extrusion layer, the pipe may be conveyed through a fluid bath and/or high humidity zone, thereby swelling the anti-extrusion layer 122 and forming fillers 124 .
[0032] Alternatively, in accordance with one or more embodiments of the present disclosure, the fillers may be created by interaction between the surface of the anti-extrusion layer and a layer that may be helically wrapped thereupon. Referring to FIG. 2 , a cross-sectional view of a pipe section in accordance with one or more embodiments of the present disclosure will be discussed. Anti-extrusion layers, first layer 220 and second layer 222 , may be wrapped around a fluid barrier 202 . Further, hoop strength wrappings 204 may form a hoop strength layer of a pipe helically wrapped over the anti-extrusion layers 220 and 222 . The top anti-extrusion layer 222 may be made of a material which may allow it to displace into gaps 228 between adjacent wrappings 204 of the hoop strength layer, such as elastomers used in the manufacturing of bonded flexible pipe. Accordingly, fillers 224 may form and may provide gap control between wrappings 204 of the hoop strength layer. Filler 224 may form as a ridge or nub and fill (or displace) between wrappings 204 , thereby preventing adjacent wrappings 204 from impacting or getting too close, thereby preventing too much rigidity in the pipe and preventing high alternating stress in the hoop strength layer when the pipe is subject to repetitive bending. Further, as filler 224 may form in each gap 228 between each wrapping 204 , it may also prevent adjacent wraps 204 from separating too much, and therefore may provide blow-through prevention. Accordingly, gaps 228 may be controlled.
[0033] In one or more embodiments of the present disclosure, wrappings 204 of a hoop strength layer may be wound on the underlying anti-extrusion layer 222 with an interference fit (see FIG. 5 ). Accordingly, the inner wrapping diameter of wrappings 204 may be smaller than an outer diameter of anti-extrusion layer 222 . For example, the interference fit between the two layers 204 and 222 may be 0.010 to 0.030 inches, such that the outer diameter of anti-extrusion layer 222 may be 0.010 to 0.030 inches larger than an inner diameter of wrapping 204 . Accordingly, wrappings 204 may impact and/or press into anti-extrusion layer 222 by an amount in that range. Those skilled in the art will appreciate that other interference fits outside of that range may be used without deviating from the scope of the present invention and the stated range is merely provided as an example. Furthermore, the amount of interference may depend, at least partially, on the thickness of the anti-extrusion layer.
[0034] As noted above, and discussed below, anti-extrusion layer 222 may have a bedding surface as an outer surface, which may be the contact surface between anti-extrusion layer 222 and wrappings 204 . Accordingly, due to the interference fit, wrappings 204 may squeeze and/or press into the bedding surface. As a result, the material of the bedding surface may displace into gaps 228 formed between adjacent wrappings 204 . The displacement may occur as a result of the wrappings 204 pressing into the bedding material, and displacing the pressed material into gaps 228 between adjacent wrappings 204 , thereby forming fillers 224 . Fillers 224 may, therefore, control the gaps between adjacent wrappings 204 .
[0035] To control gaps 228 , fillers 224 may prevent wrappings 204 from moving axially relative to the fluid barrier and may maintain gaps 228 between adjacent wrappings 204 . Wrappings 204 may, therefore, be held in approximately the same position in which they were installed, even during spooling, subsequent manufacturing operations, installation, and/or service.
[0036] As anti-extrusion layer 222 may be made with a reinforced elastomer that may allow for the formation of fillers 224 , wrappings 204 may be applied with minimal force, even with the interference fit, and thereby prevent damage to the fluid barrier during manufacture. Therefore, excessive force, collapse and/or shrinking of the fluid barrier and high pre-stress in the hoop strength layer may be avoided.
[0037] Now referring to FIG. 3 , a cross-sectional view of a pipe section in accordance with one or more embodiments of the present disclosure will be discussed. A single anti-extrusion layer 326 may be wrapped around a fluid barrier 302 . Accordingly, anti-extrusion layer 326 may be a single layer which may allow for displacement between adjacent wrappings 304 . Fillers 324 may form between adjacent wrappings 304 in gaps 328 , and thereby provide gap control, as discussed above. Further anti-extrusion layer 326 may be a reinforced structure, where the reinforcement may be provided by fibers 330 within anti-extrusion layer 326 .
[0038] Further, as shown in FIG. 3 , pressure (arrows of FIG. 3 ) may be applied from beneath fluid barrier 302 . Under normal conditions, without a gap control mechanism in accordance with one or more embodiments of the present disclosure, the pressure may tend to push fluid barrier 302 radially outward and into gaps 328 . Further, as a pipe is manufactured, stored, transported, installed, and/or used in service, the pipe may be wound, bent, and/or manipulated, thereby allowing gaps 328 to fluctuate in size. For example, the wrappings 304 may shift and/or slide relative to each other and relative to a surface of the fluid barrier 302 . As such, the gaps 328 may increase in size between some wrappings 304 , and decrease in size between other wrappings 304 . Accordingly, the amount of free space that may be in a particular gap 328 may become large, and when pressure may be applied through the pipe, the radial pressure within fluid barrier 302 may become large enough, and gap 328 may be weak enough (due to its large width), so that blow through of the fluid barrier may occur. Further, if gaps 328 are removed by shifting and/or moving of wraps 304 , regions or sections of the pipe may lose flexibility and/or cause damage to a pipe if forced to bend.
[0039] Therefore, according to one or more embodiments of the present disclosure, an anti-extrusion layer 326 may be applied between fluid barrier 302 and wrappings 304 . Anti-extrusion layer 326 may displace between adjacent wrappings 304 , thereby preventing relative movement and/or sliding of the wraps. Accordingly, gap 328 may be controlled and maintained at a desired width so as to prevent increases in the size of gap 328 , thereby preventing blow through of fluid barrier 302 . Further, gap 328 may be controlled so that the size of gap 328 may not decrease in size, thereby maintaining flexibility within the pipe.
[0040] Now referring to FIG. 4A , a top view of a gap control layer in accordance with one or more embodiments of the present disclosure will be described. Gap control layer 426 may be a reinforced tape. However, as noted above, the gap control layer may alternatively be a sleeve or extruded layer, with or without reinforcements. Fibers 435 and 436 may be threaded through gap control layer 426 to provide reinforcement and structure. The threading may be parallel to the direction of the tape, or may be perpendicular thereto, or may be a combination thereof, or may be oriented at any angle between. Accordingly, a matrix structure may be formed, with cross-weaving of reinforcement fibers 435 and 436 .
[0041] FIG. 4B shows an end-on cross-sectional view of gap control layer 426 . As shown in FIG. 4B , elastomeric layers 440 and 441 may contain parallel fibers 450 which may be supported and reinforced by woven fibers 435 and 436 and cross-knitting 460 and 461 .
[0042] FIG. 4C shows a blown-up detail of the end-on view shown in FIG. 4B . Fibers 450 may be contained and aligned with cross-knitting 460 and 461 . Cross-knitting 460 may provide a top support and cross-knitting 460 may provide a bottom support to the fibers 450 and to gap control layer 426 or may be woven within gap control layer 426 .
[0043] Although shown as reinforcement fibers, fibers 450 may be individual fibers, woven bundles, and/or other fibrous structures. Similarly, cross-knitting 460 and 461 , and woven fibers 435 and 436 , may be single fibers, bundles, woven bundles, and/or any other fiber and/or fiber structure that may provide support and/or reinforcement to gap control layer 426 . Furthermore, although fibers 450 are shown in FIG. 4B as a particular orientation, fibers 450 may be in a different orientation, such as perpendicular to that shown in FIG. 4B , or may be in a matrix form, such that FIG. 4B may represent a side cross-sectional view as well. Accordingly, variations in fibers 450 , cross-knitting 460 and 461 , and/or woven fibers 435 and 436 may be applied and/or employed without deviating from the scope of the present disclosure.
[0044] Gap control layer 426 may be 0.05 inches thick, thereby allowing only a very slight increase in the size of the pipe, but allowing for an effective control over the gaps between adjacent wrappings. However, this thickness is for example only and those skilled in the art will appreciate that the thickness of gap control layer 426 may vary in thickness without deviating from the scope of the present disclosure.
[0045] Displacement of the gap control layer between adjacent wrappings of a superimposed layer will be discussed with reference to FIG. 5 . Specifically, the anti-extrusion layer may include a lower anti-extrusion surface 541 , an upper anti-extrusion surface 540 , and reinforcement fiber bundles 550 . Reinforcement fiber bundles 550 may be further supported by cross-knitting 560 and 561 and woven fibers 535 and 536 . Hoop strength wraps 504 may be helically wound around the anti-extrusion layer. Gaps 528 may form between adjacent wraps 504 . Prior to installation of wraps 504 , upper anti-extrusion surface 540 may be represented by dashed line 555 . However, after installation of wraps 504 , upper anti-extrusion surface 540 may deform. The deformation of upper anti-extrusion surface 540 is shown by a decrease in thickness below each wrapping 504 and an increase in thickness in gaps 528 between each set of adjacent wrappings 504 . Accordingly, filler 524 may form as a gap controller, preventing wraps 504 from shifting or moving relative to the other wraps 504 or relative to a fluid barrier upon which the anti-extrusion layer may be applied. Alternatively, deformation of upper anti-extrusion surface 540 may be caused by application of a force and/or pressure 570 from beneath the lower anti-extrusion layer 541 .
[0046] Accordingly, in accordance with one or more embodiments of the present disclosure the deformation of upper anti-extrusion surface 540 may occur during factory acceptance hydrostatic pressure testing of the pipe. For example, when internal pressure 570 may be applied to the pipe, the liner 541 may be forced radially outward (upward in FIG. 5 ) toward hoop strength wraps 504 , thus squeezing filler 524 from beneath hoop strength wraps 504 into gaps 528 .
[0047] Now, referring to FIG. 6 , a cross section view of a portion of a composite flexible pipe in accordance with one or more embodiments of the present disclosure is shown. Particularly, FIG. 6 shows a cross section of a free venting pipe. For example, a free venting pipe as disclosed in U.S. Patent Application Publication No. 2008/0145583 may incorporate aspects of the present disclosure.
[0048] Specifically, with reference to FIG. 6 , anti-extrusion layers 680 and 681 , in accordance with one or more embodiments as described above, may be applied during manufacture of a free venting pipe. A free venting pipe may include a perforated core 602 , an internal hoop layer 605 , an inner anti-extrusion layer 680 , a membrane 685 , an outer anti-extrusion layer 681 , and an external hoop layer 606 . Internal hoop layer 605 may provide collapse resistance, and external hoop layer 606 may provide internal pressure resistance. Additional layers such as those discussed above, including anti-wear layers, tensile layers, and jackets, may be provided without deviating from the scope of the present disclosure.
[0049] In a pipe as shown in FIG. 6 , gaps 688 and 698 may be present between adjacent wraps of hoop layers 605 and 606 , respectively. Anti-extrusion layers 680 and 681 may be applied between the hoop layers 605 and 606 and membrane 685 . In accordance with embodiments of the present disclosure, gaps 688 and 698 may be controlled by fillers 684 and 694 , respectively.
[0050] Accordingly, anti-extrusion layers may be applied between reinforcement layers and membrane layers, to thereby control gaps in the reinforcement layers. Therefore, gap control may be achieved in an internal reinforcement layer, in addition to achieving gap control in an external reinforcement layer. As such, there may be two or more anti-extrusion layers with filler for gap control, and, particularly, on either side of a membrane.
[0051] Further, in accordance with one or more embodiments of the present disclosure, an anti-extrusion layer with bedding may be applied externally to a hoop strength reinforcement layer. The anti-extrusion layer control may potentially be improved if application of the anti-extrusion layer is made both internally and externally to a hoop strength layer, thereby allowing gap control from both sides of the hoop strength layer. Alternatively, an anti-extrusion layer with bedding may only be applied to the external surface of the hoop strength layer. For example, referring again to FIG. 3 , anti-extrusion layer 326 may be applied above hoop strength wraps 304 , instead of, or in addition to being applied between hoop strength wraps 304 and fluid barrier 302 . The anti-extrusion layer may be applied with sufficient tension so that fillers 324 may form between wraps 304 and into gaps 328 .
[0052] Advantageously, gap control in accordance with one or more embodiments of the present disclosure may provide minimum requirements to prevent blow through. According to the American Petroleum Institute Specification 17J, Table 6, “the maximum allowable reduction in wall thickness (of the internal pressure sheath) below the minimum design value due to creep in(to) the supporting structural layers shall be 30% under all load combinations.” Although this requirement is for conventional flexible pipe, the requirement also applies to flexible fiber reinforced pipe, and is a requirement to prevent blow through of a fluid barrier, internal pressure sheath, or liner. Gap control in accordance with one or more embodiments of present disclosure may provide fillers which may prevent slip between adjacent wrappings of a hoop strength layer while maintaining a minimum of less than 30% thickness reduction.
[0053] Moreover, reinforcement layers may be wound at any lay angle relative to the fluid barrier, where a high lay angle may provide hoop strength and low lay angles may provide axial strength. In some embodiments of flexible fiber reinforced pipe, the innermost structural reinforcement layer may be applied at an approximately 40° to 60° lay angle to the pipe axis. Thus, when the pipe bends, any gaps that may exist between adjacent wrappings may not open significantly. However, in accordance with one or more embodiments of the present disclosure, hoop reinforcement layers (i.e., 104 , 204 , 304 , and 504 of FIGS. 1 , 2 , 3 , and 5 , respectively) may be wound at a relatively high lay angle relative to the longitudinal axis of the pipe (i.e., 60° to 89°) to provide internal pressure resistance against burst and/or external pressure resistance against collapse. Therefore, one or more embodiments of the present disclosure may allow for a higher lay angle, thereby allowing hoop strength reinforcement instead of axial strength reinforcement.
[0054] Moreover, one or more embodiments of the present disclosure may provide control over the gaps between adjacent wrappings of a structural layer so as to prevent blow through of a fluid barrier or other layer beneath the gap control layer. Accordingly, fewer wrappings and/or applications of anti-extrusion layers may be allowed, thereby increasing the efficiency with which flexible pipes may be made. Further, fewer wrappings and/or applications may reduce the pipe diameter, reducing costs and weight.
[0055] Moreover, one or more embodiments of the present disclosure may allow a first reinforcement layer above a fluid barrier to be applied at a high lay angle, thus providing more hoop than axial strength. Accordingly, the innermost structural support layer may be a hoop strength layer, and therefore may provide burst and/or collapse resistance. Further, embodiments described herein may require less material than traditional flexible pipe, as a hoop strength layer may be applied at a smaller diameter. Further, the reinforcement may also prove a relatively “soft” layer onto which a hoop resistant layer may be applied.
[0056] Moreover, one or more embodiments of the present disclosure may provide reinforcement to a fluid barrier so as to prevent blow through. In accordance with one or more embodiments of the present disclosure, the gap control layer, which may be an anti-extrusion layer, may be applied as a single tape layer, sleeve, or extrusion, or may be applied as multiple tape layers, sleeves, and/or extrusions, or combinations thereof. Accordingly, the efficiency with which gap control may be applied may be improved.
[0057] Moreover, gap control provided by one or more embodiments of the present disclosure may be used with pipes employing internal carcass designs, free venting designs, standard annulus designs, and/or any other pipe designs where gap control may be desired, including non-interlocking steel pipe layers. Additionally, gap control layers in accordance with one or more embodiments described herein may be provided between any two consecutively wrapped layers of a pipe.
[0058] While the disclosure has been presented with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments may be devised which do not depart from the scope of the present disclosure. Accordingly, the scope of the invention should be limited only by the attached claims.
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In one aspect, the present disclosure relates to a tubular assembly with gap control. Embodiments disclosed herein relate to one or more embodiments of and methods for controlling gaps between helically wrapped layers in a pipe structure. A tubular assembly includes a fluid barrier, a first layer, and a second layer comprising a plurality of non-interlocking helical wraps and disposed on an outer surface of the first layer, in which the first layer is disposed between the fluid barrier and the second layer and configured to at least partially displace into a space created between adjacent non-interlocking helical wraps of the second layer.
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BACKGROUND OF INVENTION
[0001] The invention relates to a patient monitor and, particularly, a patient monitor for continuously monitoring one or more physiological signals of a patient and for determining a probability that a patient has acute cardiac ischemia based at least in part on one of the continuously monitored physiological signals.
[0002] Every day, patients arrive at an emergency room of a hospital complaining of chest pain. The chest pain may be a symptom indicating the patient is experiencing a myocardial infarction or, alternatively, the chest pain may be a symptom indicating the patient is experiencing a lesser medical condition (e.g., heartburn or indigestion). Statistics show that quickly identifying whether a patient is having a myocardial infarction may minimize the amount of damage to the heart. However, performing the necessary tests to correctly determine whether a patient is experiencing the myocardial infarction or heartburn are expensive.
[0003] One instrument used to predict whether a patient is likely experiencing a myocardial infarction is an electrocardiograph capable of calculating a probability that the patient has acute cardiac ischemia. If the patient has a high probability of acute cardiac ischemia, then the patient should be further tested to determine whether the patient is experiencing a heart attack. One instrument for determining a probability of a patient having acute cardiac ischemia is an Acute Cardiac Ischemia Time-insensitive Predictive Instrument (ACI-TIPI). ACI-TIPI is described in detail in Selker et al., A Tool for Judging Coronary Care Unit Admission Appropriateness, Valid for both Real - Time and Retrospective Use: Medical Care, Vol. 28, No. 7 July 1991), pp. 610-627 and Selker et al., Erratum: Medical Care, Vol. 30, No. 2 (February 1992), p. 188, both of which are incorporated herein by reference.
[0004] The ACI-TIPI calculates a score representing the probability of a patient having acute cardiac ischemia. Based on the probability of the patient having acute cardiac ischemia, an experienced doctor or technician can determine whether the patient should be admitted to the coronary care unit. Once admitted to the coronary care unit, the patient can undergo more complicated, expensive and time consuming tests to determine whether the patient is experiencing a heart attack.
[0005] Prior medical equipment having the capability of calculating a probability of a patient having acute cardiac ischemia consisted exclusively of electrocardiographs having ACI-TIPI. An example electrocardiograph capable of determining a probability that a patient has acute cardiac ischemia is the MAC™5000, which is manufactured and sold by GE Medical Systems Information Technologies, Inc. Electrocardiographs are not used for continuous, constant or ongoing patient monitoring, i.e., they typically only take a small time sample (e.g., ten to twelve seconds) of a patient's electrocardiograms (ECGs). A separate piece of medical equipment (i.e., a patient monitor) is attached to a patient for continuous, constant or ongoing monitoring of patient parameters. One such patient monitor is the DASH®2000 brand patient monitor, which is manufactured and sold by GE Medical Systems Information Technologies, Inc. Such patient monitoring devices however have not heretofore included the capability of determining the probability that a patient has acute cardiac ischemia.
SUMMARY OF INVENTION
[0006] When the patient enters the emergency room complaining of chest pains, multiple pieces of medical equipment (e.g., a patient monitor and an electrocardiograph) may be attached to the patient at any time. Attaching multiple pieces of equipment to the patient requires time for attachment, space for each piece of equipment, and coordination among the emergency room staff. In addition, the patient may be periodically moved throughout the emergency room or the hospital. Consequently, requiring an electrocardiograph to be temporarily attached to the patient requires use of extra time, space, personnel, and restricts transferability, which may affect the care provided to the patient. Therefore, it would be beneficial to have a patient monitor, and particularly a patient transport monitor, capable of determining a probability that a patient has acute cardiac ischemia.
[0007] Accordingly, the invention provides a patient monitor for determining a probability that a patient has acute cardiac ischemia. The patient monitor includes an input device connectable to a patient to continuously acquire electrocardiogram (ECG) signals from the patient, an instrumentation amplifier connected to the input terminal to combine the signals and to generate at least one ECG lead, and an analysis module. The analysis module is operable to continuously read the ECG lead, to analyze a portion of the ECG lead for a period of time, and to calculate a probability that the patient has acute cardiac ischemia based at least in part on the analyzed portion of the ECG lead.
[0008] The invention further provides a method of determining a probability that a patient has acute cardiac ischemia. The method includes the acts of providing a patient monitor having an input device connectable to a patient, acquiring electrocardiogram (ECG) signals from the patient, generating at least one ECG lead in response to acquiring the ECG signals, continuously monitoring the ECG lead, analyzing a portion of the ECG lead for a period of time, and calculating the probability that the patient has acute cardiac ischemia based at least in part on the analyzed portion of the ECG lead.
[0009] The invention further provides a software program for a patient monitor. The software program is capable of determining a probability that a patient has acute cardiac ischemia. The software program includes the acts of reading at least one electrocardiogram (ECG) lead acquired from the patient, continuously monitoring the ECG lead, analyzing a portion of the ECG lead for a period of time, and calculating the probability that the patient has acute cardiac ischemia based at least in part on the analyzed portion of the ECG lead.
[0010] Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0011] [0011]FIG. 1 is a schematic diagram of a patient monitor embodying the invention.
[0012] [0012]FIG. 2 is a flowchart implementing a method of determining a probability that a patient has acute cardiac ischemia.
DETAILED DESCRIPTION
[0013] Before one embodiment of the invention is explained in full detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of including and comprising and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.
[0014] A patient monitor 100 embodying the invention is schematically shown in FIG. 1. An example monitor embodying the invention is a GE Medical Systems Information Technologies, Inc. DASH®3000 Pro™ brand portable monitor. In general terms, the monitor 100 includes one or more input devices 105 , a central unit 110 , a data entry device 115 connected to central unit 110 , and one or more output devices 120 connected to central unit 110 .
[0015] The one or more input devices 105 include a plurality of electrodes E 1 , E 2 . . . E n that are connectable to a patient. The electrodes acquire electrical activity (i.e., ECG signals) generated by the patient. The number of electrodes E 1 , E 2 . . . E n may vary. But for the embodiment shown, the number of electrodes is equal to ten and are connected to the patient in a standard twelve-lead configuration.
[0016] The electrodes E 1 , E 2 . . . E n are connected to the central unit 110 by an interface cable 125 . The interface cable 125 provides direct communication between the electrodes E 1 , E 2 . . . E n and an input terminal 130 . The interface cable 125 allows for transmission of the acquired ECG signals from the patient to the central unit 110 . The interface cable 125 is preferably a passive cable but, alternatively, the cable 125 may contain active circuitry for amplifying and combining the ECG signals into ECG leads (discussed further below). In other embodiments, the electrodes E 1 , E 2 . . . E n may be in communication with the central unit 110 through a telemetry-based transmitter transmitting a radio frequency (RF) signal to one or more antennas connected to central unit 110 through a conventional RF receiver.
[0017] The one or more input devices 105 may further include one or more sensors S 1 , S 2 . . . S n . The sensors S 1 , S 2 . . . S n are connectable to the patient and acquire physiological signals from the patient. Example sensors may include invasive and noninvasive blood pressure sensors, carbon dioxide sensors, pulseoximetry sensors, temperature sensors, etc. Similar to electrodes E 1 , E 2 . . . E n and for the embodiment shown, the one or more sensors S 1 , S 2 . . . S n are connected to the central processing unit at input terminals 135 by interface cables 140 . In other embodiments, the one or more sensors may be in communication with the central processing unit via a telemetry transmitter as described above.
[0018] The data-entry device 115 allows an operator (e.g., a technician, nurse, doctor, etc.) to enter data into the central unit 110 . The data-entry device 115 may be incorporated within the central unit 110 (e.g., a trim knob) or, alternatively, may be a stand-alone device (e.g., a stand-alone keyboard). Example data-entry devices 115 include a trim knob, a keyboard, a keypad, a touch screen, a pointing device (e.g., a mouse, a trackball), etc.
[0019] The central unit 110 includes a power supply 147 . The power supply 147 powers the patient monitor 100 and receives input power either by an external power source 155 or an internal power source 160 (e.g., a battery).
[0020] The central unit 110 also includes amplifying-and-filtering circuitry 165 , analog-to-digital (A/D) conversion circuitry 170 , and an analysis module 175 . The amplifying-and-filtering circuitry 165 , the A/D conversion circuitry 170 , and the analysis module 175 may be discrete circuitry, may be incorporated as an integrated circuit (e.g., an application specific integrated circuit), or may be a combination of both.
[0021] The amplifying-and-filtering circuitry 165 receives the physiological signals from the input terminals 130 and 135 , and amplifies and filters (i.e., conditions) the physiological signals. For example, the amplifying-and-filtering circuitry 165 includes an instrumentation amplifier 180 . The instrumentation amplifier 180 receives the ECG signals, amplifies the signals, and filters the signals to create a multi-lead ECG. The number of leads of the multi-lead ECG may vary without changing the scope of the invention.
[0022] The A/D conversion circuitry 170 is electrically connected to the instrumentation amplifier 180 . The A/D conversion circuitry 170 receives the amplified and filtered physiological signals and converts the signals into digital physiological signals (e.g., a digital multi-lead ECG.) The digital physiological signals are then provided to the analysis module 175 which is electrically connected to the A/D conversion circuitry 170 .
[0023] The analysis module 175 reads the digital physiological signals, analyzes the signals from the A/D conversion circuitry 170 , and displays the signals and the resulting analysis to an operator. The analysis module 175 includes a controller or microprocessor 182 and internal memory 185 , and implements a software program to control the monitor 100 . The internal memory 185 includes program storage memory 190 for storing the software program and data storage memory 195 for storing data. The implementation of the software program, including determining a probability that the patient has acute cardiac ischemia, is discussed in further below.
[0024] The output devices 120 may include a printer, a display, a storage device (e.g., a magnetic disc drive, a read/write CD-ROM, etc.), a server or other processing unit connected via a network 200 , and a speaker. Of course, other output devices may be added or attached (e.g., a defibrillator), and/or one or more output devices may be incorporated within the central unit 110 . Additionally, not all of the outputs 120 are required for operation of the monitor 100 .
[0025] In operation and at act 300 (FIG. 2), an operator activates the monitor 100 . The software initializes the microprocessor 182 . The operator then attaches the electrodes E 1 , E 2 . . . E n and/or sensors S 1 , S 2 . . . S n to the patient.
[0026] At act 305 , the monitor 100 automatically identifies which input devices 105 are connected to the patient. Alternatively, the operator may inform the monitor 100 , via the data-entry device 115 , which inputs 105 are connected to the patient. Once the monitor 100 is informed from which inputs 105 to acquire physiological signals from, the monitor 100 begins continuously monitoring the physiological signals from the patient. The monitoring data may be displayed on the display, printed by the printer, stored in the data storage memory for analysis or later recall, provided to the external storage device for storage, and/or provided to the server via the network 200 .
[0027] For example and in the embodiment shown, the operator attaches ten electrodes to the patient and selects twelve-lead ECG monitoring. Once twelve-lead ECG-monitoring is selected (act 310 ), the monitor 100 continuously monitors the ECG leads generated by the patient (act 315 ). This is accomplished by acquiring electrical activity generated by the patient in the form of ECG signals. The ECG signals are transmitted to the input terminal 130 via the interface cable 125 . The ECG signals enter the central unit 110 at terminal 130 and are provided to the instrumentation amplifier 180 . The instrumentation amplifier 180 combines, amplifies and filters the ECG signals resulting in a standard twelve-lead ECG. For other electrode configurations, the number of leads of the multi-lead ECG may vary. The resulting multi-lead ECG is provided to the A/D conversion circuit 170 . The A/D conversion circuit 170 samples each lead of the multi-lead ECG to create a digital signal representing the multi-lead ECG, and provides the digital multi-lead ECG to the analysis module 175 . The analysis module 175 reads the digital multi-lead ECG signal for monitoring. The monitored twelve-lead ECG may be used to calculate a heart rate, detect an arrhythmia, measure ST-segment elevation and, as is discussed below, calculate a probability that the patient has acute cardiac ischemia. The monitor 100 continues to monitor the twelve-lead ECG until the operator exits the twelve-lead monitoring function (act 320 ). Other monitoring applications are performed similarly. The other monitoring applications include blood pressure monitoring, pulse oximetry monitoring, temperature monitoring, etc.
[0028] If the patient complains of heart pain, the operator may request the monitor 100 to perform a calculation of a probability that the patient has acute cardiac ischemia (act 325 ). For example, when a patient enters the emergency room complaining of heart pain, the emergency room staff may attach the patient monitor 100 to the patient for monitoring. In addition, a staff member (e.g., the resident emergency room doctor) may request a test to determine whether the patient has acute cardiac ischemia. In the past, an electrocardiograph and a technician would need to be requested and brought into the patient's direct area. The electrocardiograph would then need to be attached to the patient. Attaching the electrocardiograph to the patient takes valuable time. Moreover, the presence of another piece of equipment and the operator thereof connected to the patient, may inconvenience the emergency room staff. Thus, it is beneficial for the patient monitor 100 already connected to the patient for continuous, ongoing monitoring to be able to perform this function in addition to performing the monitoring function.
[0029] For the embodiment shown, the operator uses the data entry device 115 (e.g., the trim knob) to select an ACI-TIPI analysis. Once the ACI-TIPI analysis is selected (act 325 ), the software initiates an ACI-TIPI analysis subroutine (act 330 ). Although the patient monitor 100 described herein uses ACI-TIPI to determine a probability that the patient has acute cardiac ischemia, other instruments (i.e., formulas) may be used.
[0030] Specifically, the monitor 100 uses Formula 1 (below) to calculate or determine a probability that a patient has acute cardiac ischemia.
[0031] FORMULA 1 ACI-TIPI
probability % = 100 × [ 1 - 1 1 + exp ( b o + ∑ b i · x i ) ]
[0032] where: b o is a constant term, b i are coefficients, and x i are variables. The coefficients include values representing a chest pain condition, patient demographics, and ECG analysis coefficients. The variables are empirically found and act as multipliers. Formula 1 and its constant term, coefficients and variables are further described in Selker et al., A Tool for judging Coronary Care Unit Admission Appropriateness, Valid for both Real - Time and Retrospective Use: Medical Care, Vol. 28, No. 7 (July 1991), pp. 610-627 and Selker et al., Erratum: Medical Care, Vol. 30, No. 2 (February 1992), p. 188, both of which are incorporated herein by reference.
[0033] If the ACI-TIPI subroutine is selected, the patient monitor 100 proceeds to act 330 . At act 330 , the operator enters patient information. For example, the operator enters patient biographical data (e.g., patient sex and patient age) and a patient condition (e.g., chest or left arm pain is the primary complaint, chest or left arm pain is the secondary complaint, or chest or left arm pain is not present). As described above, the entered patient information is used by Formula 1 for determining a probability that a patient has acute cardiac ischemia. Other patient data may be entered when using different instruments.
[0034] Once the patient information is entered, the operator initiates the ACI-TIPI analysis (act 340 ) via the data entry device 115 . At act 345 , the software temporarily stores a portion of the monitored ECG leads for a period of time (i.e., a time window). When the ECG leads are stored, the software analyzes the stored ECG leads to obtain ECG analysis coefficients for the ACI-TIPI formula. Example ECG analysis coefficients include whether ECG Q-waves are present, whether the ECG ST segment is depressed or elevated by an amount, whether the ECG T-waves are inverted by an amount, and whether both the ECG ST segment is depressed and the ECG T-wave is inverted. The ECG analysis coefficients are used by Formula 1 to determine a probability that the patient has acute cardiac ischemia. Other ECG analysis coefficients may be used when using different instruments (i.e., different formulas). Additionally, the temporarily stored portion of the monitored ECG leads may be stored prior to the operator initiating the ACI-TIPI analysis. For example, the software may repeatedly store a portion of the monitored ECG leads for a period of time. Once the operator initiates the ACI-TIPI analysis, the software analyzes the most recently stored data to obtain ECG analysis coefficients for the ACI-TIPI formula.
[0035] At act 350 , the software calculates a probability that the patient has acute cardiac ischemia using the ACI-TIPI formula as is disclosed in Selker et al., A Tool for Judging Coronary Care Unit Admission Appropriateness, Valid for both Real - Time and Retrospective Use: Medical Care, Vol. 28, No. 7 (July 1991), pp. 610-627 and Selker et al., Erratum: Medical Care, Vol. 30, No. 2 (February 1992), p. 188. Upon completing the calculation, the resulting probability is disclosed (e.g., displayed on the monitor) to the operator (act 355 ). In addition, the software may provide a list of factors affecting or reasons for the resulting calculated probability. Example factors are shown in TABLE 1 EXAMPLE FACTORS. Based on the probability and disclosed factors (if provided), an experienced operator may determine whether the patient should be admitted to the cardiac care unit for further testing. In addition, the resulting probability and data used for calculating the probability may be stored or printed for future reference, or provided to the network 200 for additional analysis by a remote server or processor.
TABLE 1 EXAMPLE FACTORS 1. Chest or left arm pain present. 2. Chest or left arm pain is chief complaint. 3. Patient is male, less than 41 years of age. 4. Patient is male, age 41-50. 5. Patient is male, over 50 years of age. 6. Patient is female, less than 41 years of age. 7. Patient is female, age 41-50. 8. Patient is female, over 50 years of age. 9. Q waves are not present. 10. No significant Q waves detected. 11. ST segment is elevated 2 mm or more. 12. ST segment is elevated 1-2 mm. 13. ST segment is depressed 2 mm or more. 14. ST segment is depressed 1-2 mm. 15. ST segment is depressed 0.5-1 mm. 16. No abnormal ST segment deviation detected. 17. Hyperactive T-waves. 18. T waves are inverted 5 mm or more. 19. T waves are inverted 1-5 mm. 20. Flattened T waves in all frontal or precordial leads. 21. No T-wave abnormality detected.
[0036] As can be seen from the above, the invention provides a patient monitor for determining a probability that a patient has acute cardiac ischemia. The invention also provides a method of determining a probability that a patient has acute cardiac ischemia and a software tool for a patient monitor to calculate a probability that a patient has acute cardiac ischemia. Various features and advantages of the invention are set forth in the following claims.
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A patient monitor for determining a probability that a patient has acute cardiac ischemia including an input device connectable to a patient to acquire electrocardiogram (ECG) signals from the patient, an instrumentation amplifier connected to the input terminal to combine the signals and to generate at least one ECG lead, and an analysis module. The analysis module is operable to continuously read the ECG lead, to analyze a portion of the ECG lead for a period of time, and to calculate a probability that the patient has acute cardiac ischemia based at least in part on the analyzed portion of the ECG lead.
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BACKGROUND OF THE INVENTION
1. The Field of the Invention
The present invention relates to a hetero-branched radial polystyrene-polyisoprene (SIS) block copolymer used as a base polymer of pressure-sensitive adhesive compositions, and a preparation method thereof.
2. Related Prior Art
Different block polymers comprised of polystyrene-polyisoprene blocks have been used as a base polymer of pressure-sensitive adhesive compositions. Moreover, radial polystyrene-polyisoprene block polymers are known to be excellent in initial adhesion, holding power, workability, and heat stability.
Various coupling agents are available in use for the preparation of the radial polystyrene-polyisoprene block copolymers. Among the tetravalent coupling agents, SiCl 4 is most preferred in the aspect of reactivity, bond stability, price, and supply stability.
Techniques for the preparation of a radial polystyrene-polyisoprene block copolymer using SiCl 4 as a coupling agent are disclosed in, for example, U.S. Pat. Nos. 5,668,208; 5,552,493; and 6,534,593 B1.
As stated in the documents, an active lithium polymer having an isoprene terminal participates in a coupling reaction with SiCl 4 to form a polymer having three branches due to steric hindrance. The use of butadiene to solve the problem that the steric hindrance prohibits 4-branch coupling is disclosed in U.S. Pat. No. 3,840,616. The use of butadiene for 4-branch coupling in the case of polymers having an isoprene or styrene terminal is described in a Fetters and Hadjichristidis et al., ( Macromolecules, 7, 552, 1972 & 11, 668, 1978). The technologies applied to radial polystyrene-polyisoprene block copolymers based on the results of the researches are U.S. Pat. Nos. 5,292,819; and 5,399,627, WO 9220725 and WO 9514727.
More specifically, these techniques include adding less than 10% butadiene to the terminal of the isoprene block, and inducing a coupling with SiCl 4 to form 4 butadiene block branches. However, the use of the radial block copolymer having 4 butadiene block branches as a base polymer of adhesive compositions may cause a deterioration of adhesive capacity as disclosed in U.S. Pat. No. 6,534,593 B1 it is may also deteriorate heat stability of the adhesive compositions in the case of polystyrene-polyisoprene block copolymers comprised of a polystyrene-polyisoprene block alone, heat stability may be deteriorated.
Some techniques for block copolymers having both the isoprene block and the butadiene block for improvement of heat stability are already disclosed, for example, in U.S. Pat. Nos. 5,532,319; and 5,583,182.
In summary, the polystyrene-polyisoprene block copolymer forms a 3-branched polymer instead of a 4-branched polymer by a coupling reaction with a tetravalent coupling agent due to steric hindrance of the isoprene block terminal. To solve this problem, the addition of a small amount of butadiene to the isoprene block terminal is suggested. But, the use of butadiene may deteriorate adhesive capacity, while without using butadiene results in poor heat stability. Accordingly, there is a need for a novel design of the base polymer that maintains adequate adhesive capacity and viscosity stability.
SUMMARY OF THE INVENTION
In an attempt to develop radial polystyrene-polyisoprene block copolymers having a structure having optimized heat stability and adhesion property, the inventors of the present invention found out that a 4-branched radial polystyrene-polyisoprene block copolymer with one butadiene block, i.e., a 4-branched radial SIS comprised of three polystyrene-polyisoprene blocks and one polystyrene-polyisoprene-polybutadiene block, thereby completing the present invention.
It is an object of the present invention to provide a hetero-branched polystyrene-polyisoprene radial block copolymer having high holding power, good adhesion, and high heat stability.
It is another object of the present invention to provide a method for preparing the hetero-branched polystyrene-polyisoprene radial block copolymer.
To achieve the objects of the present invention, there is provided a hetero-branched radial polystyrene-polyisoprene block copolymer represented by the following formula I:
(pS-pI) 3 X-(pB-pI-pS) Formula I
where pS is polystyrene; pI is polyisoprene; pB is polybutadiene; and X is a residue of a tetravalent coupling agent.
To achieve the objects of the present invention, there is further provided a method for preparing a hetero-branched radial polystyrene-polyisoprene block copolymer that includes: (a) adding a styrene monomer in the presence of an organolithium initiator in an inert hydrocarbon solvent and proceeding polymerization until all of the monomer is consumed, to synthesize a polystyrene living polymer; (b) adding an isoprene monomer to the polystyrene living polymer and proceeding polymerization until all of the monomer is consumed, to synthesize a polystyrene-polyisoprene diblock living polymer; (c) adding a tetravalent coupling agent to the polystyrene-polyisoprene diblock living polymer and proceeding a primary coupling reaction; and (d) further adding a butadiene monomer, proceeding a secondary coupling reaction to produce a hetero-branched radial polystyrene-polyisoprene block copolymer represented by the above formula I while the butadiene monomer is consumed to form a butadiene block, and completing the reaction:
More specifically, in the present invention, the styrene monomer and the isoprene monomer are sequentially polymerized using an organolithium initiator in the presence of an inert hydrocarbon solvent, and a tetravalent coupling agent is then added for coupling to form a polymer branched with three polystyrene-polyisoprene blocks due to steric hindrance. An addition of the butadiene monomer to this polymer solution causes polymerization of the butadiene monomer to the living polystyrene-polyisoprene-Li to form one polystyrene-polyisoprene-polybutadiene block.
The tri-block copolymer thus formed participates in a secondary coupling reaction to one unreacted functional group of the 3-branch polymer to form a hetero-branched radial block copolymer having a structure of (pS-pI) 3 X-(pB-pI-pS), which includes a hetero branch, polystyrene-polyisoprene-polybutadiene block.
The present invention is directed to a radial block copolymer having a structure of (pS-pI) 3 X-(pB-pI-pS), and its preparation method.
Next, the polymerization step for the block copolymer of the present invention will be described in detail as follows.
In the step 1, a styrene monomer is added with an organolithium initiator in the presence of an inert hydrocarbon solvent and sufficiently polymerized until it is consumed (to synthesize polystyrene-Li living polymer).
The organolithium initiator as used in the present invention can be any organolithium compound that initiates polymerization of styrene, isoprene, and butadiene.
The specific examples of the organolithium initiator may include methyllithium, n-propyllithium, n-butyllithium, or sec-butyllithium. Preferably, the organolithium initiator includes n-butyllithium, or sec-butyllithium.
The inert hydrocarbon solvent for polymerization can be selected from known solvents for anionic polymerization. The suitable solvent may include aliphatic, cycloaliphatic or aromatic hydrocarbons, or mixtures of these hydrocarbons. The specific examples of the aliphatic hydrocarbons include butane, pentane, hexane, or heptane; those of the cycloaliphatic hydrocarbons include cyclohexane, cycloheptane, cyclopentane, methylcyclohexane, or methylcycloheptane; and those of the aromatic hydrocarbons include benzene, toluene, or xylene. Preferably, the solvent includes cyclohexane, a mixture of cyclohexane and n-hexane, or a mixture of cyclohexane and n-heptane.
The term “styrene”, “polystyrene’ or “pS of the formula I” as used herein does not only mean styrene specifically, but also refers to all vinyl aromatic hydrocarbon monomers. The vinyl aromatic hydrocarbon monomers available herein include alkyl-substituted styrenes, alkoxy-substituted styrenes, 2-vinyl pyridine, 4-vinyl pyridine, vinyl naphthalene, or alkyl-substituted naphthalene.
In the step 2, an isoprene monomer is added to the living polymer obtained in the step 1, polystyrene-Li polymerized until it is consumed, to synthesize a living diblock polymer (polystyrene-polyisoprene-Li).
In the step 3, a tetravalent coupling agent is added to the diblock copolymer obtained in the step 2 to produce a 3-branched polymer that includes three polystyrene-polyisoprene diblocks. The specific examples of the tetravalent coupling agent may include halogenated silicon coupling agents such as silicon tetrachloride or silicon tetrabromide; or alkoxysilanes such as tetramethoxysilane, or tetraethoxysilane. The most preferred tetravalent coupling agent is silicon tetrachloride (SiCl 4 ).
In the step 4, a butadiene monomer is added to the polymer solution of the step 3 The butadiene monomer reacts with unreacted polystyrene-polyisoprene-Li to form a triblock(polystyrene-polyisoprene-polybutadiene-Li). This polystyrene-polyisoprene-polybutadiene-Li block reacts with one unreacted functional group of the 3-branched polymer through a secondary coupling reaction to form a hetero-branched (4-branched) radial SIS represented by the formula I.
Lewis bases, which are polar compounds to increase the vinyl content of a diene polymer, are generally used in combination with a polymerization solvent so as to adequately control molecular weight distribution and polymerization rate from polymerization of the styrene monomer. The polar compounds, Lewis bases can also be used as a coupling activator to control the coupling rate in the secondary coupling step, i.e., the step 4. The Lewis bases that are a polar compound used for these purposes largely include ethers and amines. The specific examples of ethers may include diethyl ether, dibutyl ether, THF, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, dioxane, triethylene glycol ether, 1,2-dimethoxy benzene, 1,2,3-trimethoxy benzene, 1,2,4-trimethoxy benzene, 1,2,3-triethoxy benzene, or 1,2,3-tributoxy benzene. The specific examples of amines may include triethyl amine, tripropyl amine, tributyl amine, N,N,N′,N′-tetramethyl ethylene diamine, N,N,N′,N′-tetraethyl ethylene diamine, 1,2-dimorpholinoethane, 1,2-dipiperidinoethane, or Sparteine. These polar compounds can be used alone or in combination.
These polar compounds can be further added in the middle of the reaction as well as at the initial stage of the reaction. The adequate point of time for a second addition of the polar compounds is before or after the addition of the coupling agent, and also before or after a second addition of butadiene. By partially adding the polar compounds twice, i.e., at the initial and middle stages of the reaction, it is possible to control the 3,5-vinyl content of isoprene to a desired level while maintaining the microstructure of polymer.
Each step of the polymerization reaction can be performed both in the same temperature condition and in a different temperature condition, and both in the constant temperature condition and in the adiabatic temperature condition. The range of reaction temperature available is −10 to 150° C., preferably 10 to 100° C.
The styrene content of the hetero-branched radial SIS thus obtained in the present invention is in the range of 10 to 95 wt. %, and for the maintenance of adequate mechanical and applied properties, preferably 10 to 50 wt. %, most preferably 10 to 35 wt. %. If not specifically limited, the weight average molecular weight of the polystyrene block is in the range of about 5,000 to 40,000, and for the maintenance of adequate mechanical and applied properties, preferably about 5,000 to 40,000, most preferably about 8,000 to 20,000. The isoprene content of the isoprene block polymer is preferably 40 to 80 wt. %.
The weight average molecular weight of the hetero-branched radial SIS is 50,000 to 400,000, preferably 80,000 to 250,000.
The coupling rate after secondary coupling reaction is in the range of 10 to 100%, and for the maintenance of balanced mechanical properties, preferably 30 to 100%, most preferably 50 to 90%. In the present invention, the coupling rate is defined as the mass of coupled polymer divided by the sum of the mass of uncoupled polymer and the mass of coupled polymer, multiplied by 100. This can be expressed by the following equation 1.
Mass of coupled polymer/Mass of (uncoupled+coupled polymer)×100 Equation 1
The coupled rate is measured by an analysis using the gel permeation chromatography.
In the present invention, the butadiene content added after the coupling agent following the completion of the isoprene polymerization is 0.05 to 10 wt. %, preferably 0.5 to 2.0 wt. %. If the butadiene content exceeds 10 wt. %, then a deterioration of adhesive capacity and gelation may occur in using the base of the adhesive. The weight average molecular weight of the polybutadiene block thus obtained is preferably in the range of about 50 to 40,000.
As the secondary coupling reaction proceeds to a proper degree, a reaction terminator is added to complete the reaction. The specific examples of the reaction terminator may include water, alcohol, polyol, ethoxys, ketones, aldehydes, carbon dioxide, or acids. The role of the reaction terminator is deactivating the terminal of the living polymer. After the deactivation of the living polymer, a proton donating acid compound, such as phosphate, sulfate, hydrochloric acid, boric acid, or C 3 –C 20 monocarboxylic acid or polycarboxylic acid is added to adjust the pH of the polymer. Finally, an antioxidant is added and a desired dry polymer is obtained after steam stripping and drying steps.
The hetero-branched polymer thus obtained in the present invention is characterized by enhanced heat stability in the high-temperature processing condition due to the effect of the butadiene block, relative to a radial polystyrene-polyisoprene block without the butadiene block. Namely, it exhibits more excellent heat resistance because of one polystyrene-polyisoprene-polybutadiene triblock branch than the radial SIS comprising only a polystyrene-polyisoprene block. Additionally, the hetero-branched polymer has much improved harmonized properties in regard to adhesion property relative to the radial SIS having a polystyrene-polyisoprene-polybutadiene block.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail by way of the following examples, which are not intended to limit the scope of the present invention.
EXAMPLE 1
960 g of cyclohexane, 6.6 mmol of THF and 32 g of styrene were mixed in a 2 L reactor in the nitrogen atmosphere and then 2.7 mmol of n-butyllithium was added at 60° C. to initiate the reaction. After 10 minutes from the maximum temperature achieved by the exothermic reaction, 126.4 g of isoprene was added to cause a polymerization reaction. After 3 minutes from the maximum level of the isoprene polymerization temperature, 0.55 mmol of silicon tetrachloride (SiCl 4 ) was successively added to cause a coupling reaction for 5 minutes. 1.5 g of butadiene was further added to the coupled polymer solution and observed for 20 minutes or more. Every about 5 minutes, a sample of the reactant solution was completely deactivated and subjected to GPC(Gel Permeation Chromatography). The results are presented in Tables 1 and 2.
EXAMPLE 2
960 g of cyclohexane, 1.3 mmol of THF and 32 g of styrene were mixed in a 2 L reactor in the nitrogen atmosphere and then 2.7 mmol of n-butyllithium was added at 60° C. to initiate the reaction. After 10 minutes from the maximum temperature achieved by the exothermic reaction, 126.4 g of isoprene was added to cause a polymerization reaction. After 3 minutes from the maximum level of the isoprene polymerization temperature, 0.55 mmol of silicon tetrachloride (SiCl 4 ) was successively added to cause a coupling reaction for 5 minutes. 1.5 g of butadiene and 5.0 mmol of THF were further added to the coupled polymer solution and observed for 20 minutes or more. Subsequently, the reactant solution was completely deactivated and subjected to GPC. The results are presented in Table 2.
EXAMPLE 3
960 g of cyclohexane, 1.3 mmol of THF and 32 g of styrene were mixed in a 2 L reactor in the nitrogen atmosphere and then 2.7 mmol of n-butyllithium was added at 60° C. to initiate the reaction. After 10 minutes from the maximum temperature achieved by the exothermic reaction, 126.4 g of isoprene was added to cause a polymerization reaction. After 3 minutes from the maximum level of the isoprene polymerization temperature, 0.55 mmol of silicon tetrachloride (SiCl 4 ) was successively added to cause a coupling reaction for 5 minutes. 1.5 g of butadiene and 0.82 mmol of N,N,N′,N′-tetramethyl ethylene diamine(TMEDA) were further added to the coupled polymer solution and observed for 20 minutes or more. Subsequently, the reactant solution was completely deactivated and subjected to GPC. The results are presented in Table 2.
EXAMPLE 4
960 g of cyclohexane, 1.3 mmol of THF and 32 g of styrene were mixed in a 2 L reactor in the nitrogen atmosphere and then 2.7 mmol of n-butyllithium was added at 60° C. to initiate the reaction. After 10 minutes from the maximum temperature achieved by the exothermic reaction, 126.4 g of isoprene was added to cause a polymerization reaction. After 3 minutes from the maximum level of the isoprene polymerization temperature, 0.55 mmol of silicon tetrachloride (SiCl 4 ) was successively added to cause a coupling reaction for 5 minutes. 1.5 g of butadiene and 1.5 mmol of diethylene glycol dimethyl ether were further added to the coupled polymer solution and observed for 20 minutes or more. Subsequently, the reactant solution was completely deactivated and subjected to GPC. The results are presented in Table 2.
TABLE 1
Elapsed time (min.) after
Block copolymer content (%)
Coupling
addition of butadiene
4-branch
3-branch
2-branch
rate (%)
0
3.0
87
10
58
5
58
42
0
65
10
76
24
0
65
15
100
0
0
70
20
100
0
0
70
The results of Table 1 reveal that a 3-branched polymer with three polystyrene-polyisoprene blocks was mainly formed before the addition of butadiene. Upon adding the butadiene to this polymer solution, the butadiene block was added to the unreacted polystyrene-polyisophrene diblock and a secondary coupling reaction occurred with one unreacted functional group in the center of the 3-branched polymer to form a 4-branched polymer composition having a structure of (pS-pI) 3 X-(pB-pI-pS) (where X=Si). After the addition of butadiene, 4-branched and 3-branched polymers coexisted initially and, after about 15 minutes, only the 4-branched polymer was formed and this state was continued after then.
TABLE 2
Examples
1
2
3
4
Styrene (wt. %)
20
20
20
20
Isoprene (wt. %)
79
79
79
79
Butadiene (wt. %)
1.0
1.0
1.0
1.0
Polar compound
THF/—
THF/THF
THF/
THF/
(initial/middle stage of
TMEDA (1)
digyme (2)
reaction)
Coupling rate (%)
72
72
72
72
isoprene 3,4-vinyl
14
8.2
8.2
8.2
content (%)
weight average
21200
21600
20900
21000
molecular weight(Mw) of
polystyrene block
Mw of polybutadiene
1200
1100
1300
1300
block
Mw of whole block
17500
182000
178000
180000
copolymer
(Note)
(1) TMEDA: N,N,N′,N′-tetramethyl ethylene diamine
(2) digyme: diethylene glycol dimethyl ether
According to the results of Table 2, THF, the polar compound for accelerating the coupling rate in the secondary coupling step was all added at the initial stage of reaction in Example 1. As a result, the 3,4-vinyl content in the isoprene increased to 14%, as demonstrated by 1 H NMR. Contrarily, THF was added at the initial stage of reaction and further used in combination with N,N,N′,N′-tetramethyl ethylene diamine(TMEDA) and diethylene glycol dimethyl ether(digyme) at the middle stage of reaction in Examples 2, 3 and 4. In this case, the vinyl content in the isoprene lowered to 8.2% while the microstructure of the polymer as well as the coupling rate was maintained. Furthermore, the 4-branch polymer was synthesized successfully In this manner, polar compounds of the same kind or different kinds can be added separately in the initial and middle stages of reaction so as to control the vinyl content of the resultant polymer.
EXAMPLE 5
960 g of cyclohexane, 1.3 mmol of THF and 32 g of styrene were mixed in a 2 L reactor in the nitrogen atmosphere and then 2.7 mmol of n-butyllithium was added at 60° C. to initiate the reaction. After 10 minutes from the maximum temperature achieved by the exothermic reaction, 124.8 g of isoprene was added to cause a polymerization reaction. After 3 minutes from the maximum level of the isoprene polymerization temperature, 0.55 mmol of silicon tetrachloride (SiCl 4 ) was successively added to cause a coupling reaction for 5 minutes. 1.5 g of butadiene and 5.3 mmol of THF were further added to the coupled polymer solution and, after 10 minutes, a polymer terminator was added to the living polymer solution. The living polymer solution was then completely deactivated by stirring and mixed with an antioxidant to form the final product. The block copolymer thus obtained was analyzed by GPC in regard to its molecular weight and coupling rate before and after the coupling reaction. The results are presented in Table 3.
EXAMPLE 6
960 g of cyclohexane, 1.3 mmol of THF and 32 g of styrene were mixed in a 2 L reactor in the nitrogen atmosphere and then 2.7 mmol of n-butyllithium was added at 60° C. to initiate the reaction. After 10 minutes from the maximum temperature achieved by the exothermic reaction, 123.2 g of isoprene was added to cause a polymerization reaction. After 3 minutes from the maximum level of the isoprene polymerization temperature, 0.55 mmol of silicon tetrachloride(SiCl 4 ) was successively added to cause a coupling reaction. 4.8 g of butadiene and 5.3 mmol of THF were further added to the coupled polymer solution and, after 10 minutes, a polymer terminator was added to the living polymer solution. The living polymer solution was then completely deactivated by stirring and mixed with an antioxidant to form the final product. The block copolymer thus obtained was analyzed by GPC in regard to its molecular weight and coupling rate before and after the coupling reaction. The results are presented in Table 3.
EXAMPLE 7
960 g of cyclohexane, 1.3 mmol of THF and 35 g of styrene were mixed in a 2 L reactor in the nitrogen atmosphere and then 2.7 mmol of n-butyllithium was added to initiate the reaction. After 10 minutes from the maximum temperature achieved by the exothermic reaction, 124.8 g of isoprene was added to cause a polymerization reaction. After 3 minutes from the maximum level of the isoprene polymerization temperature, 0.55 mmol of silicon tetrachloride(SiCl 4 ) was successively added to cause a coupling reaction. 7.3 g of butadiene and 5.3 mmol of THF were further added to the coupled polymer solution and, after 10 minutes, a polymer terminator was added to the living polymer solution. The living polymer solution was then completely deactivated by stirring and mixed with an antioxidant to form the final product. The block copolymer thus obtained was analyzed by GPC in regard to its molecular weight and coupling rate before and after the coupling reaction. The results are presented in Table 3.
COMPARATIVE EXAMPLE 1
960 g of cyclohexane, 0.82 mmol of tetramethyl ethylene diamine and 32 g of styrene were mixed in a 2 L reactor in the nitrogen atmosphere and then 2.7 mmol of n-butyllithium was added at 60° C. to initiate the reaction. After 10 minutes from the maximum temperature achieved by the exothermic reaction, 128 g of isoprene was added to cause a polymerization reaction. After 3 minutes from the maximum level of the isoprene polymerization temperature, 0.55 mmol of silicon tetrachloride(SiCl 4 ) were successively added to cause a coupling reaction. A polymer terminator was then added to the resultant living polymer solution. The living polymer solution was completely deactivated by stirring and mixed with an antioxidant to form the final product. The block copolymer thus obtained was analyzed by GPC in regard to its molecular weight and coupling rate before and after the coupling reaction. The results are presented in Table 3.
COMPARATIVE EXAMPLE 2
960 g of cyclohexane, 1.3 mmol of THF and 32 g of styrene were mixed in a 2 L reactor in the nitrogen atmosphere and then 2.7 mmol of n-butyllithium was added at 60° C. to initiate the reaction. After 10 minutes from the maximum temperature achieved by the exothermic reaction, 124.8 g of isoprene was added to cause a polymerization reaction. After 3 minutes from the maximum level of the isoprene polymerization temperature, 5.2 g of butadiene was added to perform a polymerization reaction, and 0.55 mmol of silicon tetrachloride(SiCl 4 ) were added to cause a coupling reaction. A polymer terminator was then added to the resultant living polymer solution. The living polymer solution was then completely deactivated by stirring and mixed with an antioxidant to form the final product. The block copolymer thus obtained was analyzed by GPC in regard to its molecular weight and coupling rate before and after the coupling reaction. The results are presented in Table 3.
TABLE 3
Example
Comparative Example
5
6
7
1
2
Styrene (wt. %)
20
20
21
20
19.8
Isoprene (wt. %)
79.0
77.0
75.0
80
77
Butadiene (wt. %)
1.0
3.0
4.0
0
3.2
Catalyst (mmol)
2.7
2.7
2.7
2.7
2.7
Coupling agent (mmol)
0.55
0.55
0.55
0.55
0.55
Molecular weight (Mp)
174,000
175,000
171,000
189,000
175,000
after coupling
Molecular weight (Mp)
55,000
57,000
57,000
59,000
56,000
before coupling
Coupling rate (%)
71
72
75
75
73
Isoprene 3,4-vinyl content
8.2
8.2
8.2
9.1
8.3
(%)
Mw of polystyrene
19,500
19,000
20,200
21,000
19,800
Mw of polybutadiene
800
2,400
4,500
—
2,200
EXPERIMENTAL EXAMPLE
To analyze the block copolymers obtained in Examples 5, 6 and 7, and Comparative Examples 1 and 2 in regard to heat stability and pressure-sensitive adhesion property, block copolymer samples were prepared according to the pressure-sensitive adhesive composition of Table 4. For sufficient blending of the pressure-sensitive adhesion composition, the ingredients were stirred in a laboratory scale batch mixer at 150 to 165° C. for 2.5 hours in the nitrogen atmosphere.
The hot melt mixer was coated on a 20 to 25 μm thickness PET film.
TABLE 4
SIS polymer
100 parts by weight
Tackifier resin
100 parts by weight
(Wingtack 86 supplied by Coodyear tire & Rubber)
Oil
10 parts by weight
(WT2150 supplied by Michang petroleum)
Antioxidant
2 parts by weight
(Irganox 1010 supplied by Ciba-Geigy)
Subsequently, tests for heat stability and pressure-sensitive adhesion property were carried out according to the procedures described below.
(1) Retention of Viscosity at High Temperature (Heat Stability Test)
The melt viscosity of each pressure-sensitive adhesive composition sample was measured by means of using a Brookfield Thermosel Viscometer at 180° C. This pressure-sensitive adhesive composition sample was then heated at 180° C. for 24 hours, and its melt viscosity was measured again, thereby determining a ratio of the melt viscosity after the heating to the melt viscosity before the heating (unit: %). This ratio indicates a retention of the melt viscosity after the heat treatment. Heat stability is better as this value is greater.
(2) Color Change Test at High Temperature
Color change of the samples was checked with the heat stability test simultaneously. After pressure-sensitive adhesive composition was heated at 180° C. for 24 hours, the color was also checked.
(3) Loop Tack Testing
About 20 to 25 μm adhesive film was coated onto a polyester film. The film was allowed to dry for a minimum of 24 hours. The film was then mated with release liner, and cut into 1×5 inch strips. A test sample was then inserted into a Chemsultants International Loop Tack Tester with the adhesive side facing out.
(4) Holding Power
The cohesive strength of the adhesives was determined according to the general procedures outlined in PSTC-7 (a holding power test prescribed by the American Pressure Sensitive Tape Council). Specifically, a piece of pressure-sensitive adhesive tap having a width of 12.5 mm was adhered to paper so as to give a 12.5×12.5 mm bonded area, and its holding power was measured at 49° C.
(5) 180° Peel Adhesion
Adhesive capacity on steel by peeling at 180° was measured in g/2.5 cm and determined according to regulation PSTC 1.
The results are presented in Table 5.
TABLE 5
Comparative
Examples
examples
5
6
7
1
2
Heat
Viscosity maintenance rate
22
25
24
14
17
stability
at high temperature (%)
Color change at high
Pale
Pale
Pale
Pale
Pale
temperature
brown
brown
brown
brown
brown
pressure-
Loof tack (gf/in)
2,278
2,324
2,290
2,250
2,270
sensitive
Holding powere (min.)
>3,000
>3,000
>3,000
>3,000
>3,000
adhesive
180° peel (gf/in)
1,490
1,510
1,470
1,170
1,350
properties
As can be seen from the results of Table 5, the radial block copolymer having butadiene blocks to all the four branches in Comparative Example 2 and the radial block copolymer having isoprene blocks to all the four branches in Comparative Example 1 were poor in the retention of viscosity at high temperature relative to the radial block copolymers of Examples 5, 6 and 7. But, after 72 hours at a high temperature of 180° C., the radial block copolymers had little difference in color tone.
In regard to the pressure-sensitive adhesion property, the radial block copolymers of Examples 5, 6 and 7 showed enhanced adhesion performance relative to those of Comparative Examples 1 and 2.
Accordingly, the polymers synthesized according to the present invention were particularly excellent in heat stability and showed an adhesion property equivalent to or greater than the existing products.
As described above in detail, the 4-branched radial SIS comprised of three polystyrene-polyisoprene blocks and one polystyrene-polyisoprene-polybutadiene block according to the present invention is excellent in heat stability and adhesion property and therefore useful as a base polymer of pressure-sensitive adhesives.
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Disclosed is a hetero-branched radial block copolymer suitable as a base polymer of pressure-sensitive adhesives, the hetero-branched radial block having a hetero-branched structure comprised of polystyrene, polyisoprene, and polybutadiene blocks and being represented by
(pS-pI) 3 X-(pB-pI-pS)
wherein pS is polystyrene; pI is polyisoprene; pB is polybutadiene; and X is a residue of a tetravalent coupling agent.
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INFORMATION DISCLOSURE STATEMENT
It is well known that paper, paper board and other such materials are coated with various substances to change the color, the surface texture or the like. This coating sometimes includes a dyeing material to change the color, and often includes clay or other relatively heavy materials to fill the somewhat porous surface of a paper or paperboard to yield a smooth surface.
As is well known in the art, the manufacture of paper is a generally continuous process wherein the web has an extremely high water content, the water content being gradually reduced until the web is ultimately dried. Because of the nature of the method and apparatus for applying coatings, one is generally very limited in the selection of the stage of paper production at which the coatings are applied. Specifically, clay and the like are usually placed on the surface and scraped to the desired thickness by a roller, a doctor blade, or a similar mechanical means. This requires that the paper substrate be sufficiently strong to withstand mechanical forces as the coating is spread uniformly over the surface. There has been some effort at spraying coating materials on paper-like substrates, but the coatings have never been successfully applied using a spraying technique.
SUMMARY OF THE INVENTION
This invention relates generally to the coating of substrates, and is more particularly concerned with a method and apparatus for coating a substrate without mechanical contact with the substrate.
The present invention includes the preparation of a slurry to be used as the coating mixture, and the generation of a fog from the slurry. The fog may be mixed with fogs containing other coating materials if desired; then, the fog containing the final materials to be applied to the substrate is directed against the substrate. In the preferred embodiment, the fog and the substrate may contain static charges that assist both in contact and in retaining of the fog on the substrate, though success has been achieved without the use of the static charges.
The fog may be generated in many ways, including through the use of generally conventional spray nozzles. Another embodiment of the invention utilizes ultrasonic energy to create the fog, and perhaps by means of an ultrasonic nozzle of the type well known in the art.
Brief Description cf the Drawing
These and other features and advantages of the present invention will become apparent from consideration of the following specification when taken in conjunction with the accompanying drawing in which:
The single FIGURE is a schematic, flow diagram illustrating a method and apparatus for coating paper in accordance with the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Referring now more particularly to the drawings, and to those embodiments of the invention here presented by way of illustration, it will be seen that there is a tank designated at 10 which contains a slurry to be coated on the substrate designated at 11. It will be noticed that the substrate 11 is shown extending vertically, and moving upwardly as indicated by the arrow 12. This particular orientation of the substrate 11 is by way of illustration only, and those skilled in the art will realize that the substrate may move in any direction. While it is possible that a substrate having sufficient integrity can be moved vertically, and coated while moving vertically, the substrate also may be moving generally horizontally, for example on the wire of a Fourdrinier machine.
Returning then to the tank 10, it will be seen that the slurry is removed from the tank 10 by a pump 14, the pump 14 having its discharge connected to a line 15 for feeding a nozzle 16. The nozzle 16 breaks up the slurry from the tank 10 so that the slurry becomes a spray having very small particle size, or a fog. In the present application, the material will be referred to as a fog, and it should be understood that this term includes a range of forms from a very small particle aerosol to a relatively small particle spray.
The nozzle 16 may comprise many specific pieces of hardware. It is possible that, by using a pump 14 having sufficient pressure, the nozzle 16 may in fact be a fluid type nozzle wherein the nozzle will break up a fluid that flows therethrough to produce a fine-particle spray, or a nozzle wherein gas under pressure breaks up the liquid and mixes therewith to form the fog. It is also possible to use an ultrasonic nozzle, generally of the type disclosed in the U.S. Pat. No. 4,352,459to Berger et al. Ulatrasonic nozzles are well known in the art, and those skilled in the art will understand without further explanation.
One further form that the nozzle 16 may take is a transducer located at the bottom of the tank 18. It will be noted that the tank 18 is illustrated as having some slurry in the bottom thereof, with the fog in the upper portion of the tank 18. By placing a transducer 17 at the bottom of the tank 18, ultrasonic energy can break up the slurry into fine particles to produce the desired fog above the liquid, additional fog being generated as fog is removed for use.
It will be noted that the fog from the tank 18 is directed to a mixing chamber 19, and further that there is a second tank designated at 18A, which also has its output directed to the mixing chamber 19. If desired, one might have two or more tanks such as the tanks 18 and 18A, each of the tanks 18 and 18A containing a different slurry and different fog so that two or more materials can be coated on a substrate 11 simultaneously. In the event two or more slurries and fogs are used, the plural tanks such as 18 and 18A can be utilized, the output of all being directed to the mixing chamber 19 where the fogs are intermixed to the point of substantial homogeniety. In the event only one tank such as the tank 18 is to be used, the mixing chamber 19 may be omitted, and the output 20 from the tank 18 can be connected directly to the output 21 of the mixing chamber 19.
Another means for providing two different materials for coating the substrate 11 is to provide two or more of the tanks such as the tank 10. In the drawings, a second tank 10A is shown, and a pump 14A moves the material from the tank 10A and feeds the material through a line 15A to a nozzle 16A in the tank 18. It will therefore be understood that two different fogs are generated within the tank 18 by the nozzles 16 and 16A. The mixed fogs will then be directed to the mixing chamber 19, or directly to the application nozzle 24.
From the mixing chamber 19, the output at 21 is directed through a valve 22, then to the application nozzle generally indicated at 24. Those skilled in the art will be aware that a valve arrangement is commonly used in adjusting pressure across the web of paper, such valve arrangements being computer controlled in a plurality of sections to equalize the pressure across the web. The valve 22 here illustrated is expected to take the form of that prior art arrangement, the object being to adjust the volume of material directed to the substrate 11.
The present invention also provides injection means 23 for injecting air or other gas into the stream of fog. The injection means 23 are shown to be located adjacent to the walls of the application nozzle 24, and in this position a curtain of gas is placed along the walls to prevent the attachment of droplets on the walls.
The injection means 23, however, can replace the valve 22. A plurality of gas injectors 23 can be placed across the nozzle, or a conduit leading to the nozzle. These gas injectors can be computer controlled as with the prior art valve 22; but, the quantity of material will be varied by injecting gas to dilute the material. It will also be understood that the gas injectors 23 can be used alone, or in conjunction with a conventional valve such as the valve 22. The curtain can prevent formation of droplets on the walls, while the valve 22 can be used as the control.
In looking at the application nozzle 24, it should be understood that the fog is carried to the application nozzle 24 by the air flow produced by a fan, or centrifugal blower, 29. The output of the blower 29 is directed to the tank 18 which contains a supply of fog. A current is therefore established through the line 21 and through the valve 22, then to the application nozzle 24 and onto the substrate 11. The nozzle 24 includes a central application area 25 which receives the fog and directs the fog towards the substrate 11, and the fog will tend to move in a straight line and engage the substrate 11.
In the event some of the fog fails to engage the substrate 11 and/or fails to adhere thereto, the nozzle 24 includes a return chamber 26. The chamber 26 is connected through the line 28 to the suction side of the blower 29 so the return chamber 26 is at a lower pressure and will somewhat scavenge the area of the application nozzle 24. Also of course, the return chamber 26 acts as the intake for the blower 29. Fluid therefore flows through the line 28, through the blower 29, through the tank 18, thence through the line 20, the chamber 19, and the line 21. The valve 22 will adjust the flow and allow the desired fog to enter the application chamber 25 of the nozzle 24.
Since the flow to the application nozzle 24 may be varied, it is desirable to utilize a variable speed blower 29 in an effort to match the flow through the blower 29 to the flow to the nozzle 24. Even so, there may be times when there is excess volume at the high pressure side of the blower 29; therefore, a bleed line 27 will allow the excess to be directed to a separator 35.
To assist in causing the fog to attach to the substrate 11, it is contemplated that a static electric charge will be utilized on the fog and on the substrate 11. Those skilled in the art will readily understand that the substrate 11 can be charged, and that the fog can be charged by means of a grating or the like. For purposes of illustration, a charge generator is indicated at 30, there being only one charge generator shown. Nevertheless, it will be understood that one charge (e.g. a negative) can be generated and placed on the substrate 11 while the opposite charge (e.g. a positive) can be placed on the fog. These opposite charges will cause the fog to be attracted to the substrate 11 and stick thereto.
An important feature of the present invention is the application of the fog-containing coating material to a substrate 11 at low pressure and without mechanical manipulation or the like. This allows the system of the present invention to be utilized for coating paper anywhere along the paper production line, from the first de-watering stage until the paper has been completely dried. If desired, the paper can be manufactured and rolled up, and the rolls can be transported to another location, unrolled and then coated using the system of the present invention.
Returning briefly to the drawing, it will be seen that there is a supply of material designated at 31. This supply of material can be a larger tank, mixing means or the like to supply the coating slurry in the tank 10. Those skilled in the art will understand that any means for providing the slurry in the tank 10 is a reasonable equivalent of the supply 31 shown.
Looking again at the separator 35, the separator 35 may include any conventional filter or the like, the object of the separator 35 being to separate the gas from the liquid portion of the excess fog from the blower 29. When the gas and liquid are separated, the gas is simply discharged to atmosphere at 36, and the liquid is returned through the line 38 to the tank 10 for reuse. If it is determined that the gases discharged at 36 contain improper contaminants, some further removal of material may be necessary before the gas is discharged to the atmosphere.
It will therefore be seen that the present invention provides an extremely simple method and apparatus for coating substrates. Since the slurry to be coated on the substrate is transformed into a fog, and the fog is applied at very low pressure, it will be understood that the substrate will never be harmed, even when the substrate is largely water. The use of the electrostatic charge will assure appropriate coating of the substrate and adherence thereto until the substrate is completely dried. Further, in view of the coating technique, it will be understood that any conventional drying technique is appropriate so that infrared lamps or the like can be utilized to dry the coating on paper or board.
It will of course be understood by those skilled in the art that the particular embodiments of the invention here presented are by way of illustration only, and are meant to be in no way restrictive; therefore, numerous changes and modifications may be made, and the full use of equivalents resorted to, without departing from the spirit or scope of the invention as outlined in the appended claims.
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A coating method and apparatus allows coating of a paper substrate from any point from the first de-watering stage to a fully dried stage. The method includes the making of a fog from a coating slurry, and directing the fog to a nozzle that does not physically contact the substrate. An air current normally carries the fog; but, electrostatic charges can be applied to the substrate and the fog to cause the fog to be attracted and adhere to the substrate. Vacuum chambers contiguous with the nozzle pick up excess fog and deliver the excess to a separator for recycling.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to overpressure relief valves and, more particularly, to a variable overpressure relief valve for buoyancy compensators used for scuba diving. A buoyancy compensator is partially inflated to compensate for the weight of the equipment a diver is carrying. It is usually connected to the scuba air tank so that a diver can actuate an air flow control valve and inflate the compensator. Usually the diver increases the inflation of the buoyancy compensator a small amount when he wants to go to the surface. In order to prevent overinflation of the compensator during the diver's ascent, due to the decreasing water pressure causing too rapid a rise of the diver, or possible explosive rupture of the buoyancy compensator, a relief valve is integrated into the fabric of the compensator to permit the release of overpressure.
2. Description of the Prior Art
Standard relief valves for a buoyancy compensator (sometimes hereafter referred to as a "B.C.") include a base member which is secured to the external surface of the B.C. and provides basically an air vent passageway in the air containment chamber of the B.C. The air escape passageway vents the internal air cavity to the ambient medium which is usually water but can be air. The base member has a flange which is usually glued to the rubberized fabric material of the B.C. The base member permits a cap to be secured to the base member generally by a threaded engagement between the two. The standard valve includes a floating disk which covers the hole forming the passageway in the base member. The disk is spring biased by means of a compression spring disposed between the cap and the floating disk which keeps the disk pressed on the hole of the base member keeping it sealed shut. A pull cord is usually secured to the center of the disk and extends through the coil spring and out through the cap whereby a diver can grab the pull cord and put tension on it to pull the disk away from its sealing position on the hole in the base member. As a result, air can be released from the B.C. a desired amount and then the pull cord released to reseal the hole in the base member and stop the venting of air from the B.C.
A need exists in the art of overpressure relief valves to make the action automatic, not requiring the attention and operation of the valve by the diver which usually results in the inexact release of air which in most cases is an insufficient release of pressure. Correction usually requires successive pulls on the cord. If too long of a pull occurs, causing the release of too much air, the diver will sink, and that usually happens just as the diver is approaching the exact release of air he intended to achieve the equilibrium he desires. Therefore, there is a need for a variable overpressure relief valve which works automatically and can be preset which is the design purpose and resulting effect of the present invention.
SUMMARY OF THE INVENTION
The present invention is a variable overpressure relief valve for scuba diving buoyancy compensators. It includes a cylindrical base member having a lateral flange for air sealed securement to the material portion of a B.C. forming the inflatable air compartment thereof. The base member has a central air passageway for communication with the air compartment, and the base member is formed for releasably engaging a cap. A first or inner floating disk is disposed internally of the cylindrical cavity of the base member and is formed for sealing the air passageway. The diameter of the disk is smaller than the internal diameter of the cylindrical cavity in the base member whereby air vented from the B.C. air compartment through the air passageway can flow around the edges of the disk and out of the base member. A second or outer floating disk is secured to the first floating disk by a means which prevents separation of the disks beyond a predetermined adjustable limit and positions the second disk in a predetermined relation with respect to the first floating disk. A spring means is disposed between the floating disks and is biased to urge the disks apart. A vented cap is releasably engaged to the base member permitting air vented around the edges of the first floating disk to leave the interior of the base member. An adjustment button is reciprocably engaged to the cap and projects therethrough whereby the button can move adjustably in and out with respect to the interior of the base member. The adjustment button is interconnected to the second floating disk whereby movement of the button in or out with respect to the base member increases or decreases the spring pressure separating the floating disks depending upon whether the button moves inward or outward with respect to the vented cap. Means are provided for external control of the reciprocating movement of the button.
OBJECTS OF THE INVENTION
It is therefore an important object of the present invention to provide an improved variable overpressure relief valve for buoyancy compensators.
It is another object of the present invention to provide an adjustable overpressure relief valve which operates automatically.
It is a further object of the present invention to provide a variable pressure relief valve which can be operated by the diver wearing the B.C.
Other objects and advantages of the present invention will become apparent when the apparatus of the present invention is considered in conjunction with the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation in cross-section showing the variable overpressure relief valve of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference is made to the drawings for a description of the preferred embodiment of the present invention wherein like reference numbers represent like elements on corresponding views.
FIG. 1 shows the variable overpressure relief valve of the present invention in cross section. There shown is a cylindrical base member 11 having a lateral flange 13 for attachment to the external surface of a buoyancy compensator. The flange is usually glued to the material portion of the B.C. which forms the inflatable air compartment. It is usually located on the front of the B.C. high up where a diver's hand would naturally come to rest.
Projecting locating studs 15 center the base member 11 in the hole formed in the B.C. fabric for the purpose of gluing the flat underside of the flange 13 of the base member to the fabric of the B.C. The lateral flange formed on the base member provides a wider surface area for the purpose of gluing the base member to the B.C. rubberized fabric. The flange top surface also provides a stop surface for the cap or cover 17 when it is threadably secured to the base member. The stop surface prevents over-tightening, and provides a positioning surface for the cap to locate against. The stop function of the flange also prevents over tightening of the cap from pushing the base member away from its glued attachment to the B.C. fabric.
The base member 11 has a central air passageway 19 for communication with the inner air compartment or chamber of the buoyancy compensator. This communication passageway is surrounded by a slight flange or lip 21 which permits a sharper sealing edge or sealing surface to be projected outward of the base member for sealing with the closing element or stopper 23. The base member is provided with means for releasably engaging the cap or cover 17. In the preferred embodiment, threads are formed on the external cylindrical surface of the base member to engage internal threads formed in the cap. Other cap engagement means would work equally satisfactorily but a threaded engagement is the simplest and least expensive to manufacture because it can be molded into the two engaging elements.
A first or inner floating disk 23 is disposed internally of the cylindrical cavity of the base member 11 and is formed for sealing the air passageway 19. The diameter of the disk is smaller than the internal diameter of the cylindrical cavity of the base member so that air vented from the air compartment of the buoyancy compensator through the air passageway of the base member, flows up and over the flange or lip 21 and then outward around the edges of the floating disk. The air then flows out of the base member and into the cap where it in turn vents out through the holes 25 in the cap into the surrounding water or air. The term "floating" as used herein to describe the disks and an interconnecting bolt means that the floating elements are not interconnected to the surrounding structure that they are contained in.
The first floating disk 23 includes a pliant sealing washer 27 which is cylindrical in configuration, in the form of a ring, and it is captured in a recess in the floating disk and seals against the adjacent outward projecting lip 21 of the base member 11 surrounding the air passage 19. Other configurations than a round disk in a cylindrical cavity, such as square, oval, and polygonal shapes, could be utilized for the valve elements, but a circular configuration is the simplest to manufacture.
A second or outer floating disk 29 is interconnected to the first floating disk 23 by a means which permits reciprocating movement of the disks with respect to each other but prevents the separation of the two disks beyond a predetermined adjustable limit and positions and maintains the disks in a predetermined relation with respect to each other. In the preferred embodiment of the invention, this is accomplished by a floating bolt 31 which projects through and is captured by the second floating disk and is threadably engaged to the first floating disk. This arrangement permits the bolt to be adjusted to set a predetermined adjustable space between the disks. The bolt head is disposed in a recessed chamber formed in the second disk whereby the bolt can reciprocate freely therein but is confined in its movement thereby. It is obvious that the bolt can be inverted and screwed into the second floating disk and captured by the first floating disk to perform in the same manner.
A spring means 33 is disposed between the floating disks and is biased to urge the disks apart. In the preferred embodiment, this bias is effected by a coil spring which is centered on the inner floating disk 23 by means of a central projecting cylindrical portion 35 formed on the disk which the spring member is stretched around for positioning. The spring member bears against an inner surface of the outer floating disk 29 and is captured by a cylindrical flange 37 which projects inward or downward towards the first floating disk.
The vented cap 17 is threadably engaged to the base member. The bottom edge of the vented cover locates against the top surface of the flange 13 of the base member as well as to the internal top edge 39 of the base member. The cap could be a plug secured internally of the base member, but a cap construction is simpler and provides a plurality of locating surfaces.
An adjustment button is reciprocably engaged to the cap 17 and projects therethrough to permit the button to move adjustably in and out with respect to the interior of the base member 11. In the preferred embodiment, this is accomplished by means of an internally threaded cylindrical surface in the cap which engages the threaded external cylindrical surface of the button.
The adjustment button 41 is interconnected to the second floating disk 29 whereby movement of the button in or out with respect to the base member moves the inner disk in the same manner. The button can be provided with a slit for a screwdriver or with a knob-type surface for simple grasping and turning by the diver with his fingers. Turning of the adjustment button moves it in or out with respect to the vented cover 17. A pull cord can be inserted through the center of the button and connected to the central bolt 31 for hand or manual actuation of the inner floating disk 23 to vent the buoyancy compensator.
A spacer 43 is disposed between the adjustment button 41 and the second floating disk 29 whereby rotation of the adjustment button increases or decreases the spring pressure separating the floating disks depending upon whether the button moves inward to compress the spring 35 or outward with respect to the vented cover 17 to release the pressure on the spring and thereby releasing the pressure holding the first or inner floating disk 23 against the lips 21 of the air passageway 19. The spacer element defines an extended portion of the chamber formed in the second floating disk to accommodate reciprocating movement of the floating bolt 31 when movement of the first floating disk forces the bolt to project beyond the chamber formed in the second disk.
Thus it will be apparent from the foregoing description of the invention in its preferred form that it will fulfill all the objects and advantages attributable thereto. While it is illustrated and described in considerable detail herein, the invention is not to be limited to such details as have been set forth except as may be necessitated by the appended claims.
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A variable overpressure relief valve for a buoyancy compensator including an open hole base member for securement to a buoyancy compensator and a pair of spring biased floating disks in the base member sealing the hole and biased apart and held in place by a vented cover secured to the base member and having an adjustment button for changing the spring bias separating the floating disks.
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